Abstract:
A bearing assembly for use on a printing press is disclosed. A printing press includes a support frame. A shaft having a first end and a second end fixedly attached to the support frame, the shaft arranged to define a longitudinal axis relative to the support frame. A cylinder, the cylinder having a cylinder bore formed therethrough; and a bearing assembly having an outer circumferemce and an inner bore, the outer circumference sized insertion within the cylinder bore and the inner bore sized to rotatably engage the shaft. The bearing assembling includes an adjustment assembly including a first tapered portion and a second tapered portion, the first and second tapered portions cooperate to permit angular adjustment of the cylinder relative to the longitudinal axis of the shaft, the angular adjustment of the cylinder being about an axis perpendicular to the support shaft longitudinal axis.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims priority from co-pending application Ser. No. 09/951,926, filed on Sep. 13, 2001, the disclosure of which is hereby incorporated herein by reference in its entirety for all purposes, which was a continuation of application Ser. No. 09/312,137, filed May 14, 1999, now U.S. Pat. No.6,318,257, which was a continuation-in-part of application Ser. No. 08/920,462, filed Aug. 29, 1997, now U.S. Pat. No. 5,943,955. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates generally to a rotary offset printing press having removable impression and blanket sleeves mounted on axially rotatable plate and blanket cylinders, respectively. More specifically, the present invention relates to an improved bearing assembly for rotatably supporting such cylinders.  
       BACKGROUND OF THE INVENTION  
       [0003]     Rotary offset printing presses having rotatable cylinders and removable impression and blanket sleeves are generally well known in the art. Such presses typically operate at very high speeds and are capable of printing a high quantity of material in a relatively short period of time. A continuous web of paper passes between a pair of rotating blanket cylinders which print images on opposites sides of the paper web. Each blanket cylinder is in contact with a plate cylinder having an impression sleeve which has been inked and dampened and which transfers the images to the blanket cylinder for printing onto the web in a manner well known in the art.  
         [0004]     In order to change the printed material, such as when a newspaper, magazine or brochure is switched to a different edition, the plate cylinder is moved away from its adjacent blanket cylinder, the impression sleeve on the plate cylinder is removed, and a different impression sleeve is installed. When the changeover process is complete the press is ready for the next printing run.  
         [0005]     Many times, such changeovers occur with great frequency, such as when small jobs are being printed. Unfortunately, the process of changing the impression sleeve is very labor intensive and time consuming, and thus there is considerable down time for the press. Typically, each cylinder in the press is mounted for axial rotation between a pair of spaced apart side walls. The impression sleeves are mounted to the cylinders, and fit so snugly that the sleeves are held in place by friction. In order to move the sleeve relative to the cylinder, compressed air is forced between the inner surface of the sleeve and the outer surface of the supporting cylinder. The cushion of air expands the sleeve slightly, and allows the sleeve to slide relative to the cylinder. Thus, in order to install or remove the impression sleeve from the plate cylinder, the plate cylinder must first be disconnected and removed from the side walls. Thereafter, a new impression sleeve is placed on the cylinder in the same manner and the rotatable cylinder is reinstalled in preparation for the next printing run. As outlined above, this is a very time consuming process and seriously undermines the cost effectiveness of the press when the press is being used on relatively small jobs.  
         [0006]     A number of approaches have been attempted in order to decrease the changeover time between printing runs. For example, one approach as disclosed in U.S. Pat. No. 4,807,527 is to provide a releasable bearing on one end of the cylinder shaft. Removal of the bearing assembly creates an access hole in the press side wall and exposes one end of the cylinder shaft so that the impression sleeve can slide off the shaft through the access hole. The other end of the shaft is elongated, and during the changeover process the elongated portion of the shaft abuts an auxiliary shaft which is put in place for temporary support.  
         [0007]     Similarly, U.S. Pat. No. Re. 34,970 discloses a pivotable bearing which swings away to free up one end of the cylinder for the removal of the sleeve, and also discloses a cylinder supported by a pair of linearly retractable bearings, and finally a cylinder mounted to a swivel on one end and having a retractable bearing on the other.  
         [0008]     Unfortunately, in addition to other shortcomings, each of the prior art devices requires some means of temporary cylinder support in order to effectuate the changeover of the impression sleeve. In addition, each of the prior art devices requires that at least one of the bearing assemblies be completely disconnected from the cylinder shaft, and thus, neither of these approaches provides a cost effective solution to the problems outlined above.  
         [0009]     Another problem with prior art printing presses is that all of the rotating cylinders in the machine are mechanically connected to a single drive shaft system, which creates a number of inherent drawbacks. For example, all of the rotating cylinders and rollers in a printing press are typically connected to a common drive system, which consist of an extensive collection of drive shafts, gearboxes and pulleys, all of which is designed to spin all of the cylinders in the press at the same peripheral speed. Because all of the cylinders must have access to the same drive system, the placement of the cylinders relative to each other is severely constrained, which adds to the difficulty in changing impression sleeves on the plate cylinders. Moreover, on large presses there is noticeable lash in the drive system, which causes registration and vibration problems, both of which negatively impact print quality.  
         [0010]     Still another problem is the difficulty in maintaining acceptable print quality when longer cylinders are used. For example, because the outer end of a cantilevered cylinder may deflect, it is difficult to maintain even printing pressure along the length of the cylinder. Such a problem is of course exacerbated when longer print cylinders are used. Uneven cylinder pressure causes web wrinkling and web migration.  
         [0011]     Accordingly, there exists a need for a rotary offset printing press having cantilevered cylinders which permit fast replacement of the impression sleeve and which do not require temporary support during changeover. There also exists a need for self-driven cylinders which reduce or eliminate drive line lash and which also improve registration and overall system performance. Such cylinders will preferably be supported in such a manner that print quality is maintained even when relatively long cylinders are employed.  
         [0012]     There also exists a need for a system for supporting cylinders, whether cantilevered or not, in such a manner that the pressure between the cylinders along their length can be made substantially uniform. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a perspective view of a rotary offset printing press incorporating the cantilevered, self-driven cylinders of the present invention shown in combination with several more conventional cylinders;  
         [0014]      FIG. 2  is an enlarged cross-sectional view taken along lines  2 - 2  of  FIG. 1  and showing a blanket cylinder and plate cylinder unit incorporating the cantilevered, self-driven features of the present invention;  FIG. 3  is a fragmentary cross-sectional view taken substantially along lines  3 - 3  of  FIG. 2 ;  
         [0015]      FIG. 4  is a side elevational view taken along lines  4 - 4  of  FIG. 3  illustrating the tapered adjustment washers positioned for a zero bias angle;  
         [0016]      FIG. 5  is a side elevational view similar to  FIG. 4  but illustrating the tapered washers adjusted for a maximum bias angle;  
         [0017]      FIG. 6  is an enlarged end view, partly in section, of the end of the blanket cylinder shown in  FIG. 2  (the end of the plate cylinder being identical) and illustrating the air passage in the drive shaft flange which communicates pressurized air to the exit ports on the cylinder outer surface to facilitate removal of the blanket sleeve;  
         [0018]      FIG. 7  is an enlarged cross-sectional view of a plate cylinder and blanket cylinder unit having a mounting arrangement constructed in accordance with the teachings of the present invention;  
         [0019]      FIG. 8  is an enlarged fragmentary cross-sectional view of a central portion of the support shaft illustrating portions of the bearing assembly constructed in accordance with the teachings of the present invention;  
         [0020]      FIG. 8A  is an enlarged fragmentary cross-sectional view of a portion of the ring assembly and the inner race;  
         [0021]      FIG. 9  is an enlarged fragmentary cross-sectional view of an outboard portion of the support shaft illustrating portions of the bearing assembly constructed in accordance with the teachings of the present invention;  
         [0022]      FIG. 10  is a fragmentary view of the outboard end of the support shaft illustrating the eccentric shoulder;  
         [0023]      FIG. 11  is a elevational view taken along line  11 - 11  of  FIG. 10  illustrating the eccentric shoulder at the outboard end of the support shaft; and  
         [0024]      FIG. 12  is a schematic view of either the plate cylinder or blanket cylinder assembly illustrating the derivation of certain critical dimensions thereof. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0025]     The embodiments described herein are not intended to be exhaustive or to limit the invention to the precise form disclosed. The embodiments detailed have been chosen and described in order to best explain the principles of the invention and its practical use in order to enable others skilled in the art to follow its teachings.  
         [0026]     Referring now to the drawings,  FIG. 1  illustrates a rotary offset printing press incorporating the features of the present invention and which is generally referred to by the reference numeral  10 . Press  10  includes a frame  12  and a pair of opposing side walls  14 ,  16 . Press  10  also includes a pair of blanket cylinder assemblies  18 ,  20  between which passes a web of paper (not shown) to be printed. Each of the blanket cylinder assemblies  18 ,  20  is disposed adjacent a pair of plate cylinder assemblies  22 ,  24  and  26 ,  28 , respectively. Blanket cylinder assemblies  18 ,  20  each support a generally hollow rotatable blanket cylinder  19 ,  21 , respectively, and plate cylinder assemblies  22 ,  24 , and  26 ,  28  each support a generally hollow rotatable plate cylinder  23 ,  25 , and  27 ,  29 , respectively, in a manner which will be explained in greater detail below. Preferably, plate cylinder assemblies  22 ,  24  are interchangeable, i.e., one or the other can be used for printing at any given time, as are plate cylinder assemblies  26 ,  28 . Consequently, blanket cylinder assemblies  18 ,  20  are in contact with only one of their adjacent plate cylinder assemblies  22 ,  24  or  26 ,  28  during operation of the press  10 . Each of blanket cylinder assemblies  18 ,  20  and plate cylinder assemblies  22 ,  24  and  26 ,  28  are mounted in cantilever fashion to side wall  14  in a manner which will be discussed in greater detail below.  
         [0027]     Press  10  also includes a pair of ink roller assemblies  30 ,  32 , each of which includes a plurality of individual inking rollers. Ink roller assemblies  30 ,  32  apply ink and/or a dampening solution to their adjacent plate cylinders  22 ,  24  and  26 ,  28  respectively, in a manner well known in the art. Ink roller assemblies  30 ,  32  are rotatably mounted between side walls  14 ,  16  in a conventional manner.  
         [0028]     Referring now to  FIG. 2 , blanket cylinder assembly  20  and plate cylinder assembly  28  are shown mounted in side-by-side cantilever fashion to side wall  14 . It will be understood that the structure, function and operation of blanket cylinder assembly  18  and its adjacent plate cylinder assemblies  22 ,  24  is substantially the same as the structure, function and operation of cylinder assemblies  20  and  28  shown in.  FIG. 2 . Similarly, the structure, function and operation of plate cylinder assembly  26  is substantially the same as plate cylinder assembly  28 . Accordingly, only blanket cylinder assembly  20  and plate cylinder assembly  28  will be described in detail.  
         [0029]     Blanket cylinder assembly  20  includes a support shaft  34  having a cylindrical base  35  which extends through a bore  36  in a carriage  37 . Support shaft  34  also includes a shoulder  112  which abuts a pair of adjustment members  114 ,  116 , which are used to alter the angle of support shaft  34  relative to side wall  14  as is explained in greater detail below. Support shaft  34  is rigidly secured to carriage  37  by a plurality of mounting bolts  38 . Carriage  37  is slidably mounted in a slot  39  in side wall  14 , and is supported for linear movement within slot  39  on a plurality of linear bearing sets  40 . Carriage  37  thus permits the blanket cylinder assembly  20  to slide along a path perpendicular to the axis of support shaft  34 . Support shaft  34  includes a generally cylindrical outer surface  44  and an inboard set of bearings  46  and an outboard set of bearings  48  which rotatably support the blanket cylinder  21 . Support shaft  34  also includes a central longitudinal bore  42 , the purpose of which is discussed in greater detail below. Blanket cylinder  21  includes an internal cavity  31 , which is sized to fit over support shaft  34 . A removable cylindrical blanket sleeve  52  fits over the outer surface of blanket cylinder  21  and is held in place by friction.  
         [0030]     A drive shaft  54  extends through bore  42  of support shaft  34  and is operatively connected to a drive motor  56  by a coupling  58 . Drive motor  56  is preferably connected to a commercially available servo-controller  57 , which permits the rotational orientation of the cylinder  21  to be controlled. Drive shaft  54  includes an outer end  60  having a circular mounting flange  62  which is mounted to an annular seat  65  on the inner surface of cylinder  21  by a plurality of mounting bolts  64  spaced circumferentially about the flange  62 . As can be seen in  FIGS. 2 and 6 , flange  62  also includes a plurality of radially extending bores  66  which are aligned with a plurality of circumferentially spaced exit ports  67  through the outer surface of the blanket cylinder  21 . Outer end  60  of drive shaft  54  also includes a bore  68  which intersects each of the plurality of radial bores  66 . An air fitting  70  is affixed to the end  60  of drive shaft  54 , which permits compressed air from a supply source (not shown) to be routed through ports  67  via bore  68  and radial bores  66 , in order to permit the removal of sleeve  52  from blanket cylinder  21  in a manner commonly employed in the art. Moreover, because the blanket cylinder  21  is supported in true cantilever fashion, the sleeve  52  can be removed from blanket cylinder  21  without disconnecting bearing assemblies or providing temporary support since there is no interference from side wall  16  or from the drive system.  
         [0031]     Referring now to the plate cylinder assembly  28 , which is shown on the top when viewing  FIG. 2 , it includes a support shaft  72  having an eccentric base  73  which extends through a bore  74  in side wall  14 . Support shaft  72  also includes a shoulder  75  which abuts a pair of adjustment members  114 ,  116 , which are used to alter the angle of support shaft  72  relative to side wall  14  as is explained in greater detail below. Support shaft  72  is secured to side wall  14  by a plurality of mounting bolts  76 , thrust washer  78 , and thrust bearings  80 . Thrust washer  78  and thrust bearings  80  permit the rotation of support shaft  72  about its eccentric base  73  using a throw off lever (not shown) in order to move plate cylinder assembly  28  towards or away from blanket cylinder assembly  20  during changeover, maintenance, or adjustments of press  10 .  
         [0032]     Support shaft  72  includes a generally cylindrical outer surface  82  and an inboard set of bearings  84  and an outboard set of bearings  86  which rotatably support the plate cylinder  29 . Support shaft  72  also includes a central longitudinal bore  88 . A removable cylindrical plate or impression sleeve  90  fits over the outer surface of plate cylinder  29  and is held in place by friction. Plate cylinder  29  includes an internal cavity  33 , which is sized to fit over support shaft  72 . A drive shaft  92  extends through bore  88  of support shaft  72  and is operatively connected to a drive motor  94  by a coupling  96 . Drive motor  94  is also connected to servo-controller  57 . Drive shaft  92  includes an outer end  98  having a circular mounting flange  100  which is mounted to an annular seat  102  on the inner surface of cylinder  29  by a plurality of mounting bolts  104  spaced circumferentially about the flange  100 . Flange  100  also includes a plurality of radially extending bores  106  which are aligned with a plurality of circumferentially spaced exit ports  107  through the outer surface of plate cylinder  29 . Outer end  98  of drive shaft  92  also includes a bore  108  which intersects each of the plurality of radial bores  106 . An air fitting  110  is affixed to the end  98  of drive shaft  92 , which permits compressed air from a supply source (not shown) to be routed through ports  107  via bore  108  and radial bores  106 , in order to permit the removal of plate or impression sleeve  90  from cylinder  29  in a manner commonly employed in the art. As with the blanket cylinder  21 , because the plate cylinder  29  is supported in true cantilever fashion, the removal of impression sleeve  90  can be accomplished without disconnecting bearing assemblies or providing temporary support since there is no interference from side wall  16  or the drive system.  
         [0033]     Referring now to  FIGS. 3 through 5 , adjustment members  114 ,  116  each include a tab or handle  115 ,  117  and a central bore  119 ,  121 , respectively, which is sized to fit over the base  35  or  73  of their corresponding support shafts  34  or  72 . As shown in  FIGS. 4 and 5 , adjustment member  114  includes a narrowed portion  122  and a thickened portion  124 , while adjustment member  116  includes a narrowed portion  126  and a thickened portion  128 . As can be seen in  FIG. 2 , a set of adjustment members  114 ,  116  is disposed about each of the bases  35  and  73  of shafts  34  and  72  in abutment with the shoulders  112 ,  75 , respectively. Moreover, the adjustment members  114 ,  116  are wedged between the shoulders  112  and  75  of the support shafts  34  and  72  and the carriage  37  and side wall  14 , respectively.  
         [0034]     In operation, the support shaft  34  is mounted to carriage  37  with the adjustment members  114 ,  116  abutting the shoulder  112  adjacent the base  35 . The members  114 ,  116  are rotated to the position shown in  FIG. 4  to achieve a zero bias angle, or to the position shown in  FIG. 5  to achieve a maximum bias angle. Alternatively, the adjustment members  114 ,  116  may be positioned in a plurality of intermediate positions. When the shaft  34  is secured to the carriage  37  using mounting bolts  38 , the wedging action of the adjustment members  114 ,  116 , when adjusted to achieve a desired bias angle, effectively bends the shaft  34  slightly. Thus, and by similarly using the adjustment members  114 ,  116  associated with the support shaft  72 , the ends of the respective cylinder assemblies  20 ,  28  may be brought closer together or moved farther apart, in order to achieve a generally uniform contact pressure along the lengths of the cylinder assemblies  20  and  28 .  
         [0035]     The blanket cylinder  21  is mounted on stationary support shaft  34  on the bearing assemblies  46  and  48 , and the drive shaft  54  is inserted through bore  42 , with flange  62  being secured to the annular seat  65  by bolts  64 . Drive motor  56  is mounted to carriage  37  in a conventional manner and operatively connected to drive shaft  54  via a coupling  58 . Similarly, plate cylinder  29  is mounted on stationary support shaft  72  on the bearing assemblies  84  and  86 , and the drive shaft  92  is inserted through bore  88 , with flange  100  being secured to the annular seat  102  by bolts  104 . Drive motor  94  is mounted to eccentric base  73  of shaft  72  in a conventional manner and is operatively connected to drive shaft  92  via a coupling  96 . Finally, servo-controller  57  facilitates the proper registration of cylinder  21  relative to cylinder  29 , and also ensures that the cylinders  21 ,  29  remain synchronized and spin at the same peripheral speed.  
         [0036]     Referring now to  FIGS. 7 through 12 , a bearing support system assembled in accordance with the teachings of the present invention is generally referred to by the reference numeral  102 , and is as shown in  FIG. 7 . The bearing support system  102  is adapted for use with a rotary offset printing press  110 . The rotary offset printing press  110  may be the same or similar to the above described rotary offset printing press  10 . To the extent practical, the same or similar elements described in the above embodiment will retain the same reference characters, with the reference characters for those elements being increased by  100 .  
         [0037]     It will be understood that the bearing support  102  may be used to support either a cylinder assembly  120  (which may be a blanket cylinder assembly), or a cylinder assembly  128  (which may be a plate cylinder assembly), on a frame  112 . Preferably, each of the cylinder assemblies  120 ,  128  are mounted to the frame  112  in cantilever fashion as will be outlined in greater detail below. For the sake of brevity, only the structure and operation of the bearing assembly  102  installed on the cylinder assembly  120  will be described in detail. However, it will be understood that the bearing assembly  102  is equally adaptable for use on the cylinder assembly  128 .  
         [0038]     The cylinder assembly  120  includes a generally hollow rotatable cylinder  125  which defines an internal cavity  131  sized to fit over the support shaft  134  having a longitudinal axis or centerline designated by the reference arrow A. The cylinder  125  includes an outboard end  125   a.  The cylinder  125  is rotatably supported on the support shaft  134  by the bearing assembly  102 . The cylinder  125  may include an inner carrier sleeve  123 , and the cylinder  125  is sized to receive thereon a removable sleeve, a portion of which is viewable in  FIG. 9  and designated as  125   b,  in a manner more fully described above with respect to the first embodiment. Alternatively, the cylinder  125  may be adapted to accept thereon a conventional plate sleeve.  
         [0039]     The support shaft  134  includes a base  135  which extends through a bore  136  in a carriage  137 . Alternatively, as shown with respect to the cylinder assembly  128  mounted on a similar support shaft  134 , the base  135  may extend through a bore  139  in the frame  112 . The support shaft  134  of cylinder assembly  120  preferably includes a shoulder  212  which abuts a pair of rotatable angular shims  214 ,  216 , which shims may be used to alter the angle of the support shaft  134  relative to a sidewall  114  of the frame  112  in the manner discussed more fully with respect to the first embodiment described above. Note that the shims  214 ,  216  provide for the angular adjustment of the support shaft  134  relative to the frame  112 . Further, the support shaft  134  may be secured to the carriage  137 , and the carriage  137  may be slidable within the frame  112 , all in a manner similar to that described above with respect to the first embodiment.  
         [0040]     Preferably, the base  135  is eccentric about a centerline generally designated by the reference arrow B, which is illustrated schematically in  FIG. 11 . It will be noted that the centerlines A and B are generally offset from each other. Accordingly, as would be known to those skilled in the art, rotation of the support shaft  134  about its base  135  (i.e., by rotating the base  135  within the frame  112 ), by virtue of the eccentric connection, would cause the centerline A to circumscribe an imaginary circle when the support shaft  134  is viewed from its end.  
         [0041]     Referring again to  FIGS. 7-10 , the support shaft  134  includes a generally cylindrical outer surface  144 , and will include a first, inboard section  145  having an end  147  fixed to the carriage  137  (and hence the frame  112 ), and a second, outboard section  149  having a free end  151 . The inboard section  145  and the outboard section  149  are separated by a transition  153 , which may be rounded so as to prevent stress risers. It will be understood that the inboard section  145  will have a first stiffness, while the outboard section  149  will have a second, lesser stiffness by virtue of having a smaller cross-sectional area as would be known to those of skill in the art. The support shaft  134  further includes a central portion  152 , disposed generally outwardly of the transition  153  so as to lie generally on the inboard extent of the outboard section  149 .  
         [0042]     The bearing assembly  102  which rotatably supports the cylinder  125  on the support shaft  134  includes a first or inboard set of bearings  146  and an second or outboard set of bearings  148 . The support shaft  134  also includes a central longitudinal bore  142 , and a drive shaft  154  extends through the bore  142  of the support shaft  134  and is operatively connected to a drive motor  156 , such as by a conventional shaft coupling (not shown). Preferably, at least one of the cylinder assemblies  120 ,  128  will be provided with a linear positioning mechanism  157 . The linear positioning mechanism is preferably a linear ball screw actuator, which is commercially available from THK Corporation, although other actuators may also be employed, such as actuators available from the Actuator Division of Parker Corporation, Warner Electric, or Industrial Devices Corporation. The linear positioning mechanism  157  permits axial adjustment of the cylinder  125  relative to the support shaft  134  for purposes of sidelay registration, the importance of which is known to those of skill in the art. The drive motor  156  is preferably connected to a commercially available servo-controller (not shown), which permits the rotational orientation of the cylinder  125  to be controlled. The drive shaft  154  includes an outer end  160  having a circular mounting flange  162  which is mounted to an outer edge  165  of cylinder  125  by a plurality of mounting bolts  164  spaced circumferentially about the flange  162 . Preferably, the mounting flange is secured to the drive shaft  154  by a lock nut  162   a,  and preferably the mounting flange  162  is keyed to the drive shaft  154  so as to rotate in common therewith. A plurality of bolts  219  are provided for securing the carrier sleeve  123  to the mounting flange  162 .  
         [0043]     The flange  162  may include a plurality of radially extending bores  166  which are aligned with a plurality of circumferentially spaced exit ports  167  which are spaced about the periphery of the cylinder  125  and which extend through the outer surface thereof. The bores  166  and the exit ports  167  will permit the installation and removal of an impression sleeve (not shown) using compressed air in the manner described in greater detail above with respect to the first embodiment.  
         [0044]     Referring now to  FIG. 8 , the inboard bearing set  146  is shown. The inboard bearing set  146  includes an inner race  155 , a ring assembly  159 , and an outer bearing  161  having a fixed race  163  and a moveable race  169 . The inner race  155  is preferably a bronze ring having a convex and generally curved, spherical outer surface  171  which is curved about a theoretical center point  173 . The inner race  155  also includes a bore  175  which is sized to fit onto the outboard section  149  such that the inner race will be free to slide longitudinally along the outboard section  149  of the support shaft  134 .  
         [0045]     As shown in  FIG. 8A , the ring assembly  159  includes an outboard ring  177  and an inboard ring  179 . Each ring  177 ,  179  includes a concave and generally curved inner surface  178 ,  180 , respectively, which curved inner surfaces are curved to match the curvature of the outer surface  171  of the inner race  155 . As shown in  FIG. 8 , the rings  177 ,  179  are attached to each other using a plurality of bolts  182 , such that the ring assembly  159  generally surrounds or encompasses the inner race  155 , so as to form a ball and socket arrangement. When so disposed, the ring assembly  159  will, as a unit, be pivotable or otherwise be permitted to swivel about the inner race  155  about the center point  173  of the inner race  155 . An inboard retaining ring or member  184  is attached to the inboard side of the ring  179 , such as by a plurality of mounting bolts. Preferably, one or more shims  179   a  may be provided between the rings  177 ,  179 . The shims may be generally circular or any other suitable shape, and act to control the fit between the inner race  155  and the rings  177 ,  179 . The shims control and/or limit the clamping force of the rings  177 ,  179  on the inner race  155 , so that the ring assembly  159  will swivel properly about the inner race  155 .  
         [0046]     The outboard ring  177  includes an annular shoulder  185 , and the retaining member  184  also includes an annular shoulder  186 . The shoulders  185  and  186  cooperate to secure the inner race  163  of the outer bearing  161  to the ring assembly  159 , such that the outer bearing  161  will swivel or pivot in conjunction with the ring assembly  159  about the center point  173 .  
         [0047]     Referring again to  FIG. 8 , the outer bearing  161  preferably includes an inboard bearing  161   a  and an outboard bearing  161   b,  each having fixed inner races  163   a,    163   b,  respectively, and moveable outer races  169   a,    169   b,  respectively. A pair of spacers  187   a  and  187   b  are disposed between the bearings  161   a,    161   b.  Preferably, the spacers  187   a  and  187   b  are of unequal length, so that upon securing the bearings  161   a  and  161   b  in place as outlined below, any play in the bearings  161   a  and  161   b  will be removed.  
         [0048]     A barrier ring  188  is secured to the inner surface of the cylinder  125 , such as by securing the barrier ring  188  to the inner carrier sleeve  123 , such as by using a plurality of mounting bolts. The barrier ring  188  includes a shoulder  189 , while the inner carrier sleeve  123  includes a shoulder  190 , which shoulders  189 ,  190  cooperate to secure the outer race  169  of the bearing  161 . The barrier ring  188  includes an outer edge  191  sized to fit tightly against the inner surface of the cylinder  125 , with the outer edge  191  having defined therein an annular groove  192 . The annular groove  192  is sized to receive an O-ring seal  193  therein. The barrier ring  188  also includes an inner edge  194  sized to form a small gap  195  between the inner edge  194  and the adjacent outer surface of the support shaft  134 . The inner edge  194  of the barrier ring  188  helps to maintain lubricant inside the cavity  131 .  
         [0049]     Preferably, a shim (not shown) is provided at the interface between the retaining member  184  and the inner carrier sleeve  123 , such that the proper pressure is applied by the shoulders  189 ,  190  to the outer races  169   a  and  169   b.  Similarly, a shim (not shown) is supplied at the interface between the retaining member  184  and the inboard ring  179 , such that the proper pressure is applied by the shoulders  185 ,  186  to the inner races  163   a  and  163   b.    
         [0050]     Referring again to  FIG. 8A , the retaining member  184  includes a radially disposed bore  196  having a pin  197  disposed therein. It will be noted that the outboard section  149  of the support shaft  134  includes a longitudinal slot  198  (viewable in  FIGS. 8, 10  and  11 ), which slot  198  is sized to receive therein the pin  197 . The pin  197  may be spring loaded.  
         [0051]     Referring now to  FIG. 9 , the outboard bearing set  148  is shown. The outboard bearing set  148  includes a fixed inner race  200  and a moveable outer race  202 , which outer race  202  is preferably of split construction. Still preferably, the outboard bearing set  148  is preferably a cross roller bearing device, such as a split outer race Type RA cross roller bearing unit manufactured by THK Corporation.  
         [0052]     An eccentric adjustment mechanism  204  is provided at the free end  151  of the support shaft  134 . The adjustment mechanism  204  includes an eccentric adjustment ring  206  that is eccentrically and rotatably mounted to an eccentric mounting shoulder  207  formed in the free end  151  of the support shaft. The eccentric mounting shoulder  207  can be seen in  FIGS. 9, 10  and  11 . It will be noted that the eccentric mounting shoulder  207  is centered about a centerline generally designated by the reference arrow C, and it will be noted that the centerline C is offset from the centerline A. In the preferred embodiment in which the cylinder  125  is approximately thirty six (36) inches in length, the centerlines A and C will be offset approximately three (3) millimeters.  FIG. 11  also illustrates the preferred eccentric relationship of centerlines A, B, and C, it being understood that the entire support shaft  134  may be rotated about the centerline B as outlined above.  
         [0053]     As shown in  FIG. 9 , the fixed inner race  200  of the bearing set  148  is mounted to the circumferential outer surface  206   a  of the adjustment ring  206 . Preferably, the inner race  200  is slidable relative to the outer surface  206   a  in response to longitudinal movement of the drive shaft  154  during sidelay adjustment. Still preferably, the inner race  200  may be keyed to the outer surface  206   a  of the adjustment ring  206  in order to prevent rotation of the inner race  200 . The outer race  202  of the bearing set  148  is preferably secured by cooperating shoulders  162   b,    123   b  on the mounting flange  162  and the carrier sleeve  123 , respectively, which shoulders also control the amount of play in the outer race  202 .  
         [0054]     The adjustment ring  206  also includes an inner shoulder  209 , which is engaged by a retaining flange or ring  210  in order to clamp the adjustment ring  206  in place. The retaining ring  210  is secured to the free end  151  of the support shaft  134  by a plurality of bolts  211 .  
         [0055]     The adjustment ring.  206  also includes one or more bores  213 , while the mounting flange  162  includes one or more bores  217  which may be aligned with the bores  213 . The bores  213  and  217  may be used to insert a lubricating tool into the cavity  131  in order to provide lubricant to the bearing sets  146  and  148 . The oil level in the cavity  131  may be checked in a similar fashion. It will be noted that the mounting flange  162  also includes one or more bores  215 , which may be aligned with the bolts  211  by rotating the cylinder  125  in order to provide access to the bolts  211 . The bores  213  and  217  may also be used in order to adjust the position of the adjustment ring  206  as follows. Upon loosening the bolts  211  to release the clamping force on the adjustment ring  216 , a tool (not shown) may be inserted into bores  213  and  217 , such that by rotating the cylinder  125  (such as manually) the rotational position of the adjustment ring  216  will be changed. The bolts  211  can then be re-tightened when the adjustment ring  206  is in the desired position.  
         [0056]     Referring now to  FIG. 12 , it will be noted that the inboard bearing set, more specifically, the center of the inboard bearing set  146  (i.e., the center point  173 ) is preferably disposed a predetermined distance from the frame  112 . The calculation of this predetermined distance will be explained below, wherein:  
                                                       L 1 , L 2  =   Length                                                 
=   Deflection (at locations indicated in  FIG. 12 )                       I 1 , I 2 , I 3 =     Section Moment of Inertia           R =   Load           w =   Uniformly distributed load           E =   Modulus of Elasticity                      
 
         [0057]     With the remaining variables being known based upon a chosen support shaft having known dimensions, and for a known load, the desired ratio of L 1  to L 2  may be derived as follows, with reference being had to  FIG. 12 :  
           Δ   ⁢             1     =       w     L   2   4         8     EI   1             
         Δ   2     =       I     EI   1       ⁢     (         w     L   1   4       8     -       R     L   1   3       3       )           
         Δ   3     =       R     L   I   3         3     EI   2             
        FOR EVEN STRIPE Δ 1 =Δ 2       BUT Δ 2 =Δ 3 ∴Δ 1 =Δ 2 =Δ 3       SOLVING FOR L 1  AND L 2   
           L   1       L   2       =       +   _     ⁢           I   1     +     I   2         I   1               
       
 
         [0061]     In operation, the support shaft  134  is mounted to the frame  112  in the manner similar to that described above with respect to the first embodiment. The inner carrier sleeve  123  and the inboard bearing set  146  may be pre-assembled, such that an installer may slide the carrier sleeve  123  and the inboard bearing set  146  onto the support shaft  134 . With the cylinder  125  may be shifted toward the frame  112 , the outboard bearing set  148  and the adjustment mechanism  204  can then be assembled, with the adjustment ring  206 , the retaining ring  210 , and the mounting flange  162  secured as outlined above. Once assembled, the cylinder  125  may be secured to the mounting flange  162 .  
         [0062]     Once assembled, the bearing assembly  102  permits angular adjustment of the cylinder  120  relative to the support shaft  134  (i.e., the cylinder  120  may pivot or swivel about an axis generally designated by the reference arrow D in  FIG. 11 , which axis D extends perpendicular relative to the longitudinal axis or centerline A of the support shaft  134 . It will be understood that the axis D extends through the center point  173 . Further, the axis D may rotate about the axis A as the adjustment ring  206  is adjusted as will be outlined below. For example, the axis D may extend out of the plane of  FIGS. 7 and 8 , although as would be known to one skilled in the art, the axis D may also be disposed parallel to the plane of  FIGS. 7 and 8 , or at some angle in between.  
         [0063]     For example, when it is desired to adjust the angular position of the cylinder  125  relative to the support shaft  134 , the adjustment mechanism  204  may be used as follows. Upon loosening the bolts  211  in the manner described above, the adjustment ring  206  can be rotated using a tool inserted through the bores  213  and  217 . The eccentric ring  206  turning on the eccentric shoulder  207  in the support shaft  134  causes the outer end  125 a of the cylinder  125  to move. With the eccentric portion of the ring  206  disposed upwardly, the outboard end  125 a of the cylinder  125  will be urged upwardly. With the eccentric portion of the ring  206  disposed downwardly, the outboard end  125  of the cylinder  125  will be urged downwardly. Location of the eccentric portion of the ring  206  to either side (i.e., out of the plane of FIGS.  7  or  8  in either direction) will urge the outboard end  125   a  of the cylinder  125  out of the plane of  FIGS. 7 and 8  in a corresponding direction. When the desired angular position of the cylinder  125  relative to the support shaft  134  is reached, the bolts  211  are again tightened, which causes the retaining ring  210  to secure the adjustment ring  206  in place. By so doing, and by virtue of the swiveling or pivoting movement permitted by the ring assembly  159  mounted to the inner race  155 , printing pressure along the length of the cylinder assemblies  120 ,  128  may be controlled and made substantially uniform.  
         [0064]     Moreover, the pin-in-slot connection between the retaining member  184  and the support shaft  134  (i.e., the pin  197  carried by the retaining member  184  which engages the longitudinal slot  198  in the support shaft  134 ) enables the entire inboard bearing set  146  to move longitudinally relative to the support shaft  134  in response to longitudinal adjustments produced by the linear positioning mechanism  157 . As noted above, the bearing set  148  is longitudinally slidable relative to the ring  206  during sidelay adjustment.  
         [0065]     Those skilled in the art will appreciate that, although the teachings of the invention have been illustrated in connection with certain embodiments, there is no intent to limit the scope of this patent to such embodiments. On the contrary, the intention of this patent is to cover all modifications and embodiments fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.