Abstract:
To modify an existing printing press from its original length/cut off to a different cut off, a sub-frame may be mounted on an existing frame of a printing press. The sub-frame permits the relocation of bearing supports for various printing cylinders, such as, for example, the plate cylinders and blanket cylinders. In addition to mounting the sub-frame on the existing frame, new plate and blanket cylinders having different sizes than the plate and blanket cylinders used in the existing printing press may be mounted in the sub-frame to provide different printing lengths/cut offs. Suitable sleeves, such as the eccentric mounting sleeves may be provided as necessary in order to mount the cylinders to the sub-frame.

Description:
RELATED APPLICATIONS  
       [0001]    This application claims priority from U.S. Provisional Application Ser. No. 60/452,386, filed Mar. 6, 2003. 
     
    
     
       FIELD OF THE DISCLOSURE  
         [0002]    The present disclosure relates to printing presses and, more particularly, to a method and apparatus for changing the printing length/cutoff of an existing printing press to a new printing length/cutoff.  
         BACKGROUND OF THE DISCLOSURE  
         [0003]    In many large scale printing presses one of many factors that affect overall cost is the length of the printing operation, terned the printing length or cutoff. For example, a printing press having a relatively long printing length may require significantly more paper than a press with a shorter printing length. The additional paper required impacts the operational cost of the printing press, which ultimately has an effect on the competitiveness of the printing operation. It is known that certain printing presses may be replaced with more modern and cost-effective printing presses or with presses having a shorter cutoff. However, it is also known that the wholesale replacement of a printing press involves, at the very least, substantial capital expenditures and the incursion of significant labor costs, which costs may not be recovered for a significant length of time.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0004]    [0004]FIG. 1 is an elevational view of a printing station in a printing press having installed thereon an apparatus for changing the printing length/cutoff of the printing press assembled in accordance with the teachings of the present disclosure; and  
         [0005]    [0005]FIG. 2 is a fragmentary top plan view illustrating an exemplary manner by which a cylinder may be mounted to and installed or removed from an exemplary sub-frame attached to the existing frame of the printing press. 
     
    
     DETAILED DESCRIPTION  
       [0006]    Referring now to FIG. 1, a printing press  10  is shown. It will be understood that the printing press  10  may include a plurality of printing stations, however only a pair of printing stations  12   a  and  12   b  are shown. The printing press  10  includes a frame  14  which generally supports a number of printing cylinders, components, systems, and subsystems to be discussed below that form a part of the printing operation.  
         [0007]    Referring to FIGS. 1 and 2, the frame  14  typically includes a pair of spaced apart sides  14   a  and  14   b . Each side  14   a  and  14   b  may include a number of bores  37   a  and  37   b , respectively. Each pair of the bores  37   a  and  37   b  have a common bore axis  50  to support a print cylinder. The printing press  10  further includes a sub-frame  24  that similarly includes a pair of spaced apart sides  24   a  and  24   b . Each side  24   a  and  24   b  may include a number of bores  39   a  and  39   b , respectively. Each pair of the bores  39   a  and  39   b  have a common bore axis  60  to support a print cylinder.  
         [0008]    The bores  37   a  and  37   b  of the frame  14  are positioned on the frame relative to each other to provide operational coupling of print cylinders that have a first print length. The bores  39   a  and  39   b  of the sub-frame  24  are positioned on the sub-frame relative to each other to provide operational coupling of print cylinders that have a different print length than the first print length, which will be referred to as the second print length. As shown in FIG. 2, when the sub-frame  24  is mounted to the frame  14 , the bores  39   a  and  39   b  of the sub-frame  24  may non-concentrically align with the bores  37   a  and  37   b  of the frame  14 . In other words, the common bore axis  50  of the frame  14  and the common bore axis of the sub-frame  60  may not align when the sub-frame  24  is mounted to the frame  14 . Therefore, as will be described in the following, by mounting the sub-frame  24  to the frame  14 , the printing press  10  can be converted from having the first print length to the second print length.  
         [0009]    The sub-frame  24  is mounted to the frame  14  in any suitable manner so that the bores  39   a  and  39   b  of the sub-frame  24  properly align with the bores  37   a  and  37   b  of the frame  14  as described above and as will be described in detail below. The frame  14  and/or the sub-frame  24  may include a number of reference lines, surfaces, projections, or the like that provide the proper aligning of the sub-frame  24  and the frame  14 . For example, each of the frame sides  14   a  and  14   b  can include a plurality of dowels (not shown) that receive a corresponding number of apertures on the sub-frame sides  24   a  and  24   b , respectively, to properly align the sub-frame  24  with the frame  14 . In another example, each of the frame sides  14   a  and  14   b  can include a shallow depression (not shown) that is about the size of each of the sub-frame sides  24   a  and  24   b . Accordingly, each sub-frame side  24   a  and  24   b  can be placed in the a corresponding depression for proper alignment with the frame sides  14   a  and  14   b , respectively. In the disclosed example, the frame  14  includes or may otherwise be provided with one or more datum surfaces  28   a ,  28   b . The datum surface  28   a  is generally vertical, while the datum surface  28   b  is generally horizontal. According to the disclosed example, the datum surfaces  28   a  and  28   b  may be used in order to properly vertically and horizontally align the sub-frame  24  relative to the frame  14  of the printing press  10 .  
         [0010]    Once each of the sub-frame sides  24   a  and  24   b  are aligned with the frame sides  14   a  and  14   b , the sub-frame sides  24   a  and  24   b  can be securely fastened to the frame sides  14   a  and  14   b  with bolts  26 , pins (not shown), or other types of fasteners. One of ordinary skill in the art will readily recognize that the bolts  26  and a corresponding number of apertures in the frame  14  and/or the sub-frame  24  that support the bolts  26  can also be used to align the sub-frame sides  24   a ,  24   b  with the frame sides  14   a ,  14   b.    
         [0011]    Referring to FIG. 1, the printing station  12   a  includes a pair of plate cylinders  16   a  and  16   b  and a pair of blanket cylinders  18   a  and  18   b , which my be generally and collectively referred to herein as printing cylinders. The plate cylinders  16   a  and  16   b  and the blanket cylinders  18   a  and  18   b  straddle a path A along which the paper web (not shown) travels. The printing station  12   a  also includes an ink roller train  20   a , which in the disclosed example consists of five individual rollers, and a dampening system  22   a , which in the disclosed example consists of two individual rollers. The ink roller train  20   a  and the dampening system  22   a  are associated with the plate cylinder  16   a  and the blanket cylinder  18   a . Similarly, the printing station  12   b  includes an ink roller train  20   b , which in the disclosed example includes five individual rollers, and also includes a dampening system  22   b , which in the disclosed example includes two individual rollers.  
         [0012]    The ink roller train  20   b  and the dampening system  22   b  are associated with the plate cylinder  16   b  and the blanket cylinder  18   b . It will be understood that the precise details of the ink roller trains  20   a ,  20   b  and the dampening systems  22   a  and  22   b  may vary in accordance with the requirements of any given printing press. Similarly, it will be understood that the printing press  10  may include additional components (no shown) which are known to those of skill in the art. Also, the printing station  12   b  may be substantially similar to the printing station  12   a  described above, and therefore in the interest of brevity the printing station  12   b  need not be described in detail herein.  
         [0013]    Referring to FIG. 2, because the printing cylinders of the printing press  10  may have very similar or identical structures, only one of the printing cylinders, namely the plate cylinder  16   a  is shown in detail and will be described in the following. The plate cylinder  16   a  includes a shaft  17  having a first shaft end  19   a  and a second shaft end  19   b . The second shaft end  19   b  may be a drive end. The shaft ends  19   a  and  19   b  include shaft end bearing assemblies  36   a  and  36   b , respectively. Each shaft end bearing assembly  36   a  and  36   b  includes a bearing  34   a  and  34   b , respectively. Each of the shaft end bearing assemblies  36   a  and  36   b  also includes an eccentric mounting sleeve  30   a  and  30   b , respectively. Similarly, as shown in FIG. 1, each of the blanket cylinders  18   a  and  18   b  can include an eccentric mounting sleeve  32   a  and  32   b , respectively.  
         [0014]    The shaft end bearing assemblies  36   a  and  36   b  of the plate cylinder  16   a  are mounted to the sub-frame  24  using a split-side retainer  38  (only one retainer  38  is shown in FIG. 2). The retainer  38  may include two halves  38   a ,  38   b , which, when joined together, form a generally doughnut-shaped retainer. The bearings  34   a  and  34   b  along with the sleeves  30   a  and  30   b  may slide axially relative to the cylinder  16   a  to permit installation of the cylinder  16   a  on the sub-frame  24 . The retainers  38  serve to properly position the bearings axially on the cylinder  16   a  and to secure the sleeves  30   a  and  30   b  to the sub-frame  24 .  
         [0015]    The sub-frame  24  is configured to permit the print cylinders to swing between the two configurations shown in FIG. 2. For example, the sub-frame  24  may include an appropriate slot  40  sized to permit the eccentric sleeve  30   a  and the bearing  34   a  to be moved out of the sub-frame  24  as shown in FIG. 2. Thus, when the sleeves  30   a ,  30   b  and/or the bearings  34   a ,  34   b  are shifted toward the center of the cylinder  16   a , the ends  19   a ,  19   b  may be positioned through the bores  39   a  and  39   b , and possibly through the bores  37   a  and  37   b , thus allowing the cylinder  16   a  to be positioned as shown in FIG. 2. Subsequently, the sleeves and the bearings are shifted outwardly such that they may be mounted to the sub-frame  24  and secured using the retainer  38 .  
         [0016]    In accordance with disclosed example, wherein the printing press  10  is an existing printing press  10 , the printing press  10  may be converted from its original printing length to a different print length, while the frame  14  of the printing press  10 , the main drive train (not shown), the ink roller train  20   a  and  20   b , and the dampening systems  22   a  and  22   b  remain essentially intact. In other words, those systems in place on the printing press  10  prior to incorporating the apparatus of the present disclosure need not be replaced. Therefore, modifying an existing printing press  10  in accordance with the teachings of the present disclosure saves significantly on the cost of dismantling, shipping, and assembly, and a significant amount of parts, systems, and sub-structures remain in place and/or are reused after the printing press has been modified with the new printing length/cutoff. Further, most if not all of the electrical wiring, piping and ducting in place on the existing printing press may also remain undisturbed.  
         [0017]    In accordance with the disclosed examples, to modify the existing printing press  10  from its original print length to a different print length, the sub-frame  24  having the sides  24   a  and  24   b  may be mounted on the existing frame  14  of the printing press  10 . Prior to mounting the sub-frame  24  to the frame  14 , however, the print cylinders of the frame  14 , which are all sized to provide the first print length, are removed from the frame  14 . The sides  24   a  and  24   b  of the sub-frame can be mounted to the sides  14   a  and  14   b , respectively, of the frame  14 . The sides  24   a  and  24   b  of the sub-frame  24  may be located precisely both vertically and horizontally and relative to each other, using the above described datum surfaces  28   a  and  28   b . The sides  24   a  and  24   b  of the sub-frame  24  may be suitably fastened to the corresponding sides  24   a  and  24   b  of the frame  24  with pins, bolts or other types of fasteners.  
         [0018]    When the sub-frame  24  is mounted to the frame  14 , the bores  39   a  and  39   b  of the sub-frame  24  may align with the bores  37   a  and  37   b  of the frame  24 , respectively. However, the bores  39   a  and  39   b  may not align concentrically with the bores  37   a  and  37   b  of the frame  14 . In other words, the common bore axis  60  of the bores  39   a  and  39   b  may not align with the common bore axis  60  of the corresponding bores  37   a  and  37   b . Accordingly, when the print cylinders having a print length of the second size are mounted on the sub-frame  24 , the shaft end bearing assemblies  36   a  and  36   b  of the print cylinders are operatively mounted in the bores  39   a  and  39   b  of the sub-frame  24 . However, because the bores  39   a  and  39   b  of the sub-frame  24  may be aligned with the bores  37   a  and  37   b  of the frame  14 , the shaft ends  19   a  and  19   b  of the print cylinders can extend into the bores  37   a  and  37   b  of the frame  14 . As shown in FIG. 2, such extension of the shaft end  19   b  may be necessary since the shaft end  19   b  is the driven end of the shaft  17  and may be connected to a drive source.  
         [0019]    After the sub-frame  24  is mounted to the frame  14 , the printing cylinders having the second print length can be mounted to the sub-frame  24  as shown in FIG. 2. Each print cylinder can be mounted in the sub-frame  24  by first inserting the second shaft end  19   b  in the bore  39   b  of the sub-frame  24 . It may be necessary, however, to first slide the bearing assemblies  36   a  and  36   b  toward the center of the print cylinder. The first shaft end  19   a , which includes the bearing assembly  36   a  can be swung into the bore  39   a  through the slot  40 , as described above. The bearing assemblies  36   a  and  36   b  can be moved outward from the center of the printing cylinder and positioned in the bores  39   a  and  39   b , respectively. The eccentric sleeves  30   a  and  30   b  can then be adjusted to provide the proper operative coupling between the printing cylinders. The split retainer  38  may then be installed over the bearing assembly  36   a  and bolted to the appropriate eccentric mounting sleeve  30   a  in order to properly locate the bearing  34   a  within the sleeve  30   a . A separate retainer (not shown) may be installed at the opposite end of the cylinder to hold the bearing  34   b  and the sleeve  30   b  at the shaft end  19   b  in place in a similar manner.  
         [0020]    In accordance with another aspect of the disclosed example, much if not all of the main drive (not shown) may be retained intact or nearly intact. New gearing appropriate for the new cylinders may be provided as needed. Adapter plates and/or eccentric sleeves/studs may be used to reposition gears to accommodate the position of the existing main drive gear.  
         [0021]    In accordance with yet another aspect of the disclosed example, a printing press  10  can be provided with a number of sub-frames  24 . Each sub-frame  24  can include a plurality of bores that can support print cylinders having a print length that is different than the print length of the existing printing press  10  and the other sub-frames  24 . Accordingly, the printing press  10  is readily adaptable for conversion to different printing lengths in accordance with the number of sub-frames  24  provided. Each sub-frame  24  can be mounted to the frame  14  of the printing press  10  as described in the foregoing to change the print length of the printing press  10 .  
         [0022]    Numerous modifications and alternative embodiments of the invention will be apparent to those skilled in the art in view of the forgoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the system may be varied substantially without departing from the spirit of the invention, and the exclusive use of all modifications which are within the scope of the claims is reserved.