Abstract:
A folder superstructure is provided including a lead roll, a nip roll biasing the lead roll, and a frame supporting the lead roll and the nip roll. The frame is selectively movable between a first position where the lead roll and the nip roll act on a first web ribbon and a second position where the lead roll and the nip roll act on a second web ribbon. A method for folding printed webs is also provided.

Description:
BACKGROUND OF INVENTION 
       [0001]    The present invention relates generally to printing presses and more specifically to a ribbon transport for a folder superstructure. 
         [0002]    U.S. Pat. No. 6,578,479 discloses a method of operating a web-fed rotary printing machine. A web, on the web path through the rotary printing machine, runs successively through a first pull unit upstream of the printing unit, a sixth pull unit embodied by the cooling unit, and a second pull unit upstream of the turner bars. A slitting device divides the web into two web streams, each of which passes through one of respective third pull devices. A fourth pull device is located upstream of the folding former, and a fifth pull device is located downstream of the folding former. 
         [0003]    U.S. Pat. No. 7,191,704 discloses a web-fed press including a plurality of reel carriers and a plurality of groups of printing units. Following the printing of the printing material in the printing units, the printing material is supplied to a folder superstructure. 
         [0004]    U.S. Pat. Pub. 2006/0157924 discloses a folder superstructure in which ribbon bundles formed from printed webs pass over pull rolls, then past gathering rolls to an RTF. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    A folder superstructure is provided including a lead roll, a nip roll biasing the lead roll, and a frame supporting the lead roll and the nip roll. The frame is selectively movable between a first position where the lead roll and the nip roll act on a first web ribbon and a second position where the lead roll and the nip roll act on a second web ribbon. 
         [0006]    A method for folding printed webs is provided. The method includes folding a first web using a lead roll and nip roll in a first position, moving the lead roll and nip roll to a second position, and folding a second web using the lead roll and nip roll. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The present invention is described below by reference to the following drawing, in which: 
           [0008]      FIG. 1  shows a schematic side view of a printing device according to an embodiment of the present invention; 
           [0009]      FIG. 2  shows an enlarged side view of a folder superstructure shown in  FIG. 1  including a linear motion device  160 ; 
           [0010]      FIG. 3  shows an enlarged side view of a first printing press shown in  FIG. 1 ; and 
           [0011]      FIG. 4  shows an enlarged side view of a second printing press shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0012]    In a web printing press a web is commonly slit into a number of ribbons. The ribbons are translated towards a former by multiple rolls and the former acts to longitudinally fold these ribbon bundles. The rolls may translate the ribbons by acting on the ribbons alone or in pairs, where often one roll in the pair is driven and in turn rotates the other roll. As shown in the prior art, ribbons normally are only fed to a former by a printing unit or printing units from one direction. If the need arises to change to a printing unit or units located in a different direction, additional driven motors or rolls would need to be added to accept ribbons from that new direction. 
         [0013]      FIG. 1  shows a side view of a printing device  18  according to an embodiment of the present invention. Printing system  18  includes a first printing press  20 , a second printing press  40 , and a folder superstructure  17  that can work with each printing press  20 ,  40 . Folder superstructure  17  may include ribbon transport system  19 , a gathering roll  14  and a former  12 . Ribbon transport system  19  may include lead rolls  11 , nip rolls  15 , a movable frame  16  and a motor  21  driving leads  11 . In an alternative embodiment lead rolls  11  may be driven by separate motors. Ribbon transport system  19  either acts on first web ribbons  30  printed by first printing press  20  or second web ribbons  50  printed by second printing press  40 . 
         [0014]      FIG. 1  shows ribbon transport system  19  in a first position indicated by solid lines and indicated as position “A” in  FIG. 2 , acting on first web ribbons  30 .  FIG. 1  also shows dotted lines representing how ribbon transport system  19  would be positioned in a second position, indicated as position “B” in  FIG. 2 , when ribbon transport system  19  acts on second web ribbons  50 . Lead rolls  11 , nip rolls  15 , and motor  21  can be mounted on movable frame  16 . Frame  16  is configured to move lead rolls  11 , nip rolls  15  and motor  21  between at least the first position, position “A,” and the second position, position “B.” 
         [0015]    As shown in  FIGS. 1 and 3 , first printing press  20  includes a plurality of first printing units  22 ,  23 ,  24 ,  25 . First printing units  22 ,  23 ,  24 ,  25  print images on a first web  26  as web  26  passes through printing units  22 ,  23 ,  24 ,  25 . First web  26  is then slit by a first slitting device  28  into two or more first web ribbons  30 . First web ribbons  30  then enter ribbon transport system  19  of folder superstructure  17 . First web ribbons  30  are translated to gathering roll  14  by lead rolls  11  and nip rolls  15 . First web ribbons  30  are translated by being biased against lead rolls  11  by nip rolls  15  as lead rolls  11  are rotated counter clockwise by motor  21 . Gathering roll  14  then directs first web ribbons  30  to former  12 , which longitudinally folds first web ribbons  30 . After first web ribbons  30  are longitudinally folded, transport rolls  13  direct first web ribbons  30  away from former  12  and possibly toward additional post-press equipment, such as folders, trimmers, collators, perforators, stitchers, inserters, or any other post-press equipment found in a lithographic printing press. 
         [0016]    Lead rolls  11 , nip rolls  15 , and gathering roll  14  only act on first web ribbons  30  when lead rolls  11  and nip rolls  15  are located in first position, position “A.” In position “A”, lead rolls  11  are positioned on the right side of an axis C, thus allowing lead rolls  11 , nip rolls  15  and gathering roll  14  to direct first web ribbons  30  from printing units  22 ,  23 ,  24 ,  25  to former  12  for longitudinal folding along axis C. 
         [0017]    As shown in  FIGS. 1 and 4 , second printing press  40  includes a plurality of second printing units  42 ,  43 ,  44 ,  45 . A second web  46  is fed through second printing units  42 ,  43 ,  44 ,  45 . Second printing units  42 ,  43 ,  44 ,  45  print images on second web  46  as web  46  passes through printing units  42 ,  43 ,  44 ,  45 . Second web  46  is then slit by a second slitting device  48  into two or more second web ribbons  50 . Second web ribbons  50  are then directed to ribbon transport system  19  of folder superstructure  17 . Lead rolls  11  and nip rolls  15  then translate second web ribbons  50  to gathering roll  14 . Second web ribbons  50  are translated by being biased against lead rolls  11  by nip rolls  15  as lead rolls  11  are rotated clockwise by motor  21 . Gathering roll  14  then directs second web ribbons  50  to former  12 , which longitudinally folds second web ribbons  50 . After second web ribbons  50  are longitudinally folded, transport rolls  13  direct second web ribbons  50  away from former  12  and possibly toward additional post-press equipment, such as folders, trimmers, collators, perforators, stitchers, inserters, or any other post-press equipment found in a lithographic printing press. 
         [0018]    Lead rolls  11 , nip rolls  15 , and gathering roll  14  only act on second web ribbons  50  when lead rolls  11  and nip rolls  15  are located in second position, position “B.” In position “B”, lead rolls  11  are positioned on the left side of an axis C, as shown in  FIG. 1 . This allows lead rolls  11 , nip rolls  15  and gathering roll  14  to pull second web ribbons  50  from second printing press  40 , along axis C to former  12  for longitudinal folding. 
         [0019]    A sensing element  150 , for example a limit switch or proximity sensor, may be used to detect a position of ribbon transport system  19  by detecting a position of one or more lead rolls, a position of one or more nip rolls  15  or a position of movable frame  16 . A controller  60  may receive signals from sensing element  150  and direct motor  21  to rotate lead rolls  11  based on the position of ribbon transport system  19 . Motor  21  may be mounted directly on movable frame  16 . 
         [0020]      FIG. 2  shows an enlarged schematic side view of ribbon transport system  19  shown in  FIG. 1 .  FIG. 2  depicts position “A” and position “B.” Ribbon transport system  19  can be moved between position “A” and position “B,” thus allowing former  12  to accept web ribbons  30  or  50  from printing presses  20  or  40 , respectively, without requiring another set of lead rolls, nip rolls, or motor. To change the source of web ribbons  30  or  50  from first printing press  20  to second printing press  40  ( FIG. 1 ), frame  16  is moved from position “A” to position “B.” To switch back to first printing press  20  from second printing press  40 , movable frame  16  is moved from position “B” to position “A”. Frame  16  may be moved between the printing positions by a linear motion device  160 ; for example: pneumatic cylinder, hydraulic cylinder, linear motor, motor/lead screw arrangement; or by manual movement by a machine operator. Frame  16  may also be held in place in a printing position by a stabilizing or locking mechanism. 
         [0021]    In a preferred embodiment, when driven lead rolls  11  are in position to pull web ribbons  30  or  50  from one of the printing presses  20 ,  40 , sensing element  150  can be used to determine whether ribbon transport system  19  is in position “A” or position “B.” Sensing element  150  sends a signal to controller  60  which automatically determines a corresponding direction lead rolls  11  need to be rotated and causes motor  21  to rotate lead rolls  11  in the corresponding direction. For example, if movable frame  16  is in position “A”, sensing element  150  informs controller  60  and controller  60  may cause lead rolls  11  to be rotated counter clockwise by motor  21 . If frame  16  is in position “B”, sensing element  150  can inform controller  60  and controller  60  can cause the lead rolls  11  to be rotated clockwise by motor  21 . Controller  160  may also control linear motion device  160 . 
         [0022]      FIG. 3  shows an enlarged side view of first printing press  20  shown in  FIG. 1 , with ribbon transport system  19  in first transport position. Movable frame  16 , along with lead rolls  11  and nip rolls  15 , is arranged in position “A.” Printing units  22 ,  23 ,  24 ,  25  print images on web  26 , which is cut first slitting device  28  into first web ribbons  30 . Lead rolls  11  and nip rolls  15  are positioned to translate first web ribbons  30  to former  12 . Controller  60  receives a signal from sensing element  150  indicating ribbon transport system is in position “A” and motor  21  rotates lead rolls  11  counterclockwise. 
         [0023]      FIG. 4  shows an enlarged side view of second printing press  40  shown in  FIG. 1 , with ribbon transport system  19  in second transport position. Movable frame  16  is arranged in position “B.” Printing units  42 ,  43 ,  44 ,  45  print images on web  46 , which is cut first slitting device  48  into first web ribbons  50 . Lead rolls  11  and nip rolls  15  are positioned to translate first web ribbons  50  to former  12 . Controller  60  receives a signal from sensing element  150  indicating ribbon transport system is in position “B” and motor  21  rotates lead rolls  11  clockwise. 
         [0024]    Although the embodiment shown in  FIGS. 1 to 4  show ribbon transport system  19  in a horizontal alignment, the present invention is not limited to such an alignment. For example, ribbon transport system  19  may be arranged so that frame  16  slides vertically between positions “A” and “B,” or even so that frame  16  is translated horizontally and vertically. Such an arrangement may be necessary, depending upon the arrangement of first printing press  20  and second printing press  40 , and former  12 . 
         [0025]    In the preceding specification, the invention has been described with reference to specific exemplary embodiments and examples thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative manner rather than a restrictive sense.