Patent Publication Number: US-6655276-B1

Title: Device for driving folding rolls

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to printing presses and more particularly to a device and method for driving folding rolls in a folder. 
     2. Background Information 
     Web printing presses print a continuous web of material, such as paper. In a folder of the printing press, the continuous web then is cut into signatures in a cutting unit and folded. 
     One way to fold the resulting signatures is using a rotary blade folder, which includes a cylinder with rotary blades which provide a fold to the signature. The fold is forced by the blade toward two rotating folding rolls, which grip the signature along the fold at a nip, set the fold and deliver the folded product, for example, to a fan unit. Each of the folding rolls must be driven. 
     As shown in FIG. 4 herein, in a prior art rotary blade folder the drives for the interacting folding rolls include drive-in gears  1 ,  2  and roll gears  3 ,  4 . The two drive-in gears  1 ,  2  interact in a geared 1:1 relationship, and each of the drive-in gears  1 ,  2  independently drives a roll gear  3 ,  4  respectively, gears  3  and  4  being coaxial with a respective folding roll. The coaxial gears  3 ,  4  and the folding rolls are adjustable about centers of gears  1 ,  2  as shown by arrows  5 ,  6 , so that a nip between the folding rolls can be adjusted, for example to accommodate different printed product thicknesses. A seal or cover  8 , shown schematically, generally surrounds all four of the gears of the folder drive, i.e. the two drive-in gears  1 , 2  and the two coaxial gears  3 , 4 . The seal  8  helps provide for proper lubrication of the gears. However, because the two coaxial gears  3 ,  4  need to be moved during adjustment of a nip between the folding rolls, the seal  8  typically suffers flexing at location  7 , which can lead to breakdown of the seal and/or leakage of lubricating oil. 
     BRIEF SUMMARY OF THE INVENTION 
     An object of the present invention is to provide for a device and method for providing improved sealing for gears of a folder drive. An additional or alternative object of the present invention is to provide a high quality folder drive and related method. 
     The present invention provides a drive for two interacting folding rolls, the drive including a first drive-in gear, a first roll gear driven by the first drive-in gear, a first cover for sealing the first drive-in gear and the first roll gear, a second drive-in gear, a second roll gear driven by the second drive-in gear and adjustable with respect to the first roll gear, and a second cover for sealing the second drive-in gear and the second roll gear. 
     With the two-seal arrangement of the present invention, flexing or stressing of a seal can be avoided, even during nip adjustment when the first and second roll gears are moved. 
     The first and second roll gears preferably are coaxial to their respective folder rolls. 
     The first and second drive-in gears preferably are connected by a first axle and a second axle, respectively, to a first and second drive gears. First and second drive gears preferably intermesh. At least one of the first and second drive gears is connected to a drive motor. 
     The first and second axles preferably pass through a gear side wall of the folder, the drive-in gears being located inside the gear side wall and the drive gears being located outside the gear side wall. 
     One of the folding cylinders preferably is a rotary blade folding cylinder. 
     The first cover preferably is attached to a nip adjustment arm connected to one of the folding rolls, so as to move with the nip adjustment arm. 
     The present invention also provides a folder for a printing press including a first folding roll, a second folding roll interacting with the first folding roll for processing signatures, a first drive-in gear, a first roll gear connected to the first folding roll and being driven by the first drive-in gear and a first cover for sealing the first drive-in gear and the first roll gear. A second drive-in gear drives a second roll gear connected to the second folding roll, the second roll gear being adjustable with respect to the first roll gear. A second cover seals the second drive-in gear and the second roll gear. 
     The present invention also provides a method for sealing a drive of interacting first and second folding cylinders comprising the steps of: 
     sealing a first drive-in gear and a first cylinder gear of the first folding cylinder using a first cover, and 
     sealing a second drive-in gear and a second cylinder gear of the second folding cylinder using a second cover, the first cylinder gear being adjustable with respect to the second cylinder gear. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred embodiment of the present invention is described below by reference to the following drawings, in which: 
     FIG. 1 shows a view of the folder drive of the present invention; 
     FIG. 2 shows a view of the folder drive of the present invention through section A—A of FIG. 1, with certain features also shown for added clarity; 
     FIG. 3 shows a schematic view of a cut through section B—B of FIG. 1; and 
     FIG. 4 shows a prior art folder drive. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 shows a side view of a drive  10  for a rotary blade folder  20 , which includes a folding roll  22 . Drive  10  includes a first drive gear  12  which can be driven by a motor, for example. First drive gear  12  rotates an axle  14 , which is rotatingly supported in a gear side frame  30  of the folder via bearings  32 . Axle  14  is supported on the other end by sealed bearings  16  supported in an extension  34  bolted to frame  30  via an integral end plate  234 . 
     Axle  14  rotates a drive-in gear  18 , which is geared, for example in a toothed arrangement, to a roll gear  21  coaxial with the axis of and connected to folding roll  22 . The two folding rolls  22 ,  122  create an ingoing nip. The fold is created with a tucking blade that tucks the cut signature into the ingoing nip of the two folding rolls  22 ,  122 . 
     Drive gear  12  thus drives folding roll  22  by rotating axle  14 , drive-in gear  18  and roll gear  21 . 
     Supported rotatingly by a bearing  36  on the outer side of extension  34  is a nip adjustment arm  40 , which is adjustable by a nip adjustment device  42 . A top section  41  of nip adjustment arm  40  is connected to folding roll  22  through a bearing  44 . The nip adjustment device  42  can move the top section  41  about extension  34  (i.e. generally into and out of the page as shown in FIG.  1 ), so as to move roll  22 , while gears  21  and  18  remain engaged. 
     A cover  50  seals drive-in gear  18  and roll gear  21 . Cover  50  may be for example made of steel, and is attached at one side along or to nip adjustment arm  44  and at the other side  51  with a V-seal sealingly about folding roll  22 . At the bottom of cover  50  an oil drain  52  may be provided. Cover  50  thus may move with nip adjustment arm  44  and is not subject to flexing or stress as a result of a nip adjustment of roll  22 . 
     FIG. 2 shows a view of the folder drive  10  of the present invention through section A—A of FIG. 1, with certain features also shown for added clarity. Nip adjustment arm  40  can rotate about extension  34  and bearing  36  through nip adjustment device  42 . Top end  41  of nip adjustment arm  40  moves as indicated by arrow  43 , and can move folding roll  22  (shown schematically by a circle with a line) through bearing  44  (FIG.  1 ). 
     A second folding roll  122  (also shown schematically) interacts with folding roll  22  in the folder and is driven by a second drive section  110  of drive  10 . Second drive section  100  has an axle  114  supported in an extension  134  of gear side frame  30 . A bearing  136  permits a second nip adjustment arm  140  to move the second folding roll in direction  143 . 
     Nip adjustment device  42  is connected by bolts  61 ,  62  to gear side frame  30  (FIG. 1) and includes a worm drive  63  for rotating a screw axle  64  through gear  66 . Depending on the rotational direction of screw axle  64 , guides  65 ,  165  move toward each other or apart from each other along screw axle  64  by virtue of the screw motion, i.e. guides  65 ,  165 , which may be spring-loaded, have interior grooves interacting with the screw axle  64 . Guides  65 ,  165  are connected to the top ends  41 ,  141  of nip adjustment arms  40 ,  140 , respectively, and thus can move the nip adjustment arms  40 ,  140  about extensions  34 ,  134 . When nip adjustment arm  40  moves, bearings  44  move folding roll  22  as well. Bearings are also provided in nip adjustment arm  140  for folding roll  122 . 
     Thus by rotation of worm drive  63  the nip distance between the folding roller  22  and the second folding roller  122 , shown schematically in FIG. 2, can be adjusted. 
     Also shown for clarity in FIG. 2 are end plates  234  and  334  which are integral with extensions  34  and  134 , respectively, and are attached by bolts to frame  30 , which is not shown in FIG. 2 for clarity purposes. 
     Also shown for clarity purposes is drive gear  12 , which can be geared outside of frame  30  to a second drive gear  112  driving axle  114 . 
     FIG. 3 shows second axle  114  driving a second drive-in gear  118 , which in turn rotates a second roll gear  121 . Second roll gear  121  is coaxial with and drives second folding roller  121 . Also shown in FIG. 3 is axle  14 , drive-in gear  18 , first roll gear  21  and first folding roll  22 . 
     Cover  50  is shown schematically surrounding gears  21  and  18 , and is penetrated in a sealed relationship at a first side  51  (FIG. 1) by rotating folding roll  22 . Cover  50  on the other side may be attached sealingly to nip adjustment arm  40  (FIG.  2 ). Thus when nip adjustment arm  40  is moved, cover  50  also moves. 
     In a similar fashion, a cover  150  seals gears  121  and  118 , is penetrated in a sealed relationship by rotating folding roll  22  and can move with second nip adjustment arm  140  (FIG.  2 ). 
     The two independent covers  50 ,  150  thus reduce stresses and possible problems associated with leakage in lubricating the gears  18 ,  21 ,  118  and  121 . 
     FIG. 4 shows a prior art folder drive, which is described in the Background Information section herein. 
     Bearings  44  and  16  and  36  may be seal bearings. Alternatively, cover  50  could have a second side which is penetrated sealingly solely by axle  14  and the far end of roll  22 .