Mounting printing plate cylinder having tapered bore to untapered rotatable drive shaft

Information

  • Patent Grant
  • 6363850
  • Patent Number
    6,363,850
  • Date Filed
    Monday, November 22, 1999
    24 years ago
  • Date Issued
    Tuesday, April 2, 2002
    22 years ago
Abstract
A printing plate or decorator cylinder has a tapered bore for engaging the tapered outer surface of a sleeve member which is mounted on an untapered rotatable drive shaft and the sleeve is adjustably coupled to the shaft to permit accurate registration of the printed indicia when a printing plate is changed.
Description




FIELD OF THE INVENTION




This invention is directed toward adjustably mounting a printing plate cylinder, for example a magnetic cylinder to a rotatable drive shaft of a printing press or the like.




DESCRIPTION OF THE PRIOR ART




U.S. Pat. No. 5,819,648 by Megyesi point out some of the problems encountered in using a printing plate cylinder, such as a magnetic cylinder, in printing presses and decorator machines and the like. In practice the printing plate or decorator plate usually has to be changed often which in many cases requires that the printing plate cylinder with attached plate has to be removed from the drive shaft and a new plate installed, or a different cylinder with an attached printing plate installed on the drive shaft. Each time the printing plate is changed it may require some small amounts of adjustment both axially and circumferentially to bring the indicia on the new printing plate into proper registration with respect to other printed indicia. The Megyesi '648 patent describes some of the problems associated with removal and replacement of the printing plate cylinders on a decorator machine and the need to have adjustments available to bring the indicia on the printing plate into close registration with the other printed indicia. As is well-known in the commercial field and as mentioned in the '648 patent, some printing presses or decorator machines have straight or right angle cylindrical rotatable shafts and others have tapered shafts. The untapered shaft generally allows for easier adjustability but repeated replacement usually causes some wear to the bore of the printing plate cylinder and/or the shaft. The tapered shaft has the advantage of minimizing the amount of wear caused by repeated replacements but lacks adjustability. The '648 patent utilizes an inner member or sleeve which has a tapered or conical shaped axial bore to engage a tapered rotatable drive shaft. The outer surface of the sleeve is untapered to engage the untapered axial bore of an outer sleeve or printing plate cylinder. In this arrangement to bring the printing plate into registration the outer printing plate cylinder is adjusted with respect to the inner sleeve which remains mated to or engaged with the tapered shaft. To gain the advantage of a tapered shaft when the printing plate or decorator plate has to be changed the entire combination of the inner member or sleeve and the outer member or printing plate cylinder (as well as the attached printing plate) is removed from the shaft and replaced with a new similar combination with a new printing plate or a new printing plate is replaced on the printing plate cylinder and the same unit or assembly is then reinserted on the tapered drive shaft.




Another embodiment of an adjustable printing plate cylinder by the same applicants as the instant application is a printing plate cylinder with a linear bearing press-fitted into the bore for engaging an untapered rotatable printing press drive shaft. The linear bearing minimizes the wear which normally is encountered when mounting the cylinder on an untapered drive shaft and also allows for both axial and circumferential adjustment of the printing plate cylinder as needed.




SUMMARY OF THE INVENTION




A sleeve member has an untapered bore for engaging and surrounding an untapered rotatable drive shaft of a printing press or the like and fits snugly but adjustably on the untapered drive shaft. The outer surface of the sleeve is tapered. A printing plate cylinder has a correspondingly tapered axial bore for engaging the outer surface of the sleeve member. When replacing a printing plate, only the printing plate cylinder, with attached printing plate, is removed from the sleeve member which remains engaged with the drive shaft. The tapered coupling between the sleeve member and the printing plate cylinder produces some benefits attributable to a tapered shaft yet at the same time, the untapered bore of the sleeve member engaging the untapered shaft retains the benefit of the adjustability feature associated with an untapered drive shaft. When a printing plate is changed only the printing plate cylinder (with attached printing plate) is removed. Because of the tapered bore of the printing plate cylinder it can then be replaced onto the outer tapered surface of the sleeve member so that the printing place is close to the ultimate registration. The sleeve member can then be adjusted both axially and circumferentially with respect to the drive shaft to bring the printing plate into precise registration.




In the aforementioned Megyesi device, because of the weight of the assembly which has to be removed from and replaced on the shaft when replacing a printing plate, the outer sleeve of the Megyesi device preferably is made out of a lighter weight metal such as aluminum. By comparison, since the instant invention requires only that the outer printing plate cylinder be removed and replaced for changing the printing plate it can be made out of a heavier metal such as steel. The parts made of steel are more uniform and are more stable (hold their dimensions better) and can be machined more accurately and precisely. This results in a significant savings in manufacturing costs and registration can be more accurate and precise.




In the '648 patent, when changing printing plates both the inner and outer members are removed from the shaft and the assembly is usually cleaned (to remove ink and other materials). The cleaning process may result in dissolving surface lubrication between the members which is used to keep the members from binding up. Therefore, the usual practice is to separate the members after they are removed from the shaft and then relubricate after cleaning. In the instant invention only the printing plate cylinder is removed and cleaned before replacing on the sleeve. The lubrication is between the shaft and the bore of the sleeve which remains untouched and unchanged during replacement of a printing plate. Therefore, relubrication is not required.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a partial section side view of a preferred embodiment of the invention;





FIG. 2

is an end view of an end cap which is attached to the sleeve and used for adjustment of the printing plate cylinder;





FIG. 3

is an end view of a push/pull block utilized for adjustment of the printing plate cylinder;





FIG. 4

illustrates a shouldered bolt;





FIG. 5

is an end view of the mounting ring for attaching the printing plate cylinder to the sleeve; and





FIG. 6

is an end view of the printing plate cylinder.











DESCRIPTION OF THE PREFERRED EMBODIMENTS




Referring to

FIG. 1

, a cylindrical untapered printing press drive shaft


10


is attached in conventional fashion at one end to a conventional driving source identified generally by reference numeral


11


for rotatably driving the shaft in a conventional and well-known fashion. A sleeve


12


has a central or axial untapered cylindrical bore


13


for engaging shaft


10


with its outer surface


14


tapered generally inward from the attached end of shaft


10


to the open or distal end of the shaft for a significant length and continues with a cylindrical or untapered length identified by reference numeral


15


. The outer end of sleeve


12


has an inward extending flange. The bore


13


of sleeve


12


fits over and surrounds shaft


10


snugly yet it can be adjusted both circumferentially and axially a small amount as necessary with respect to the shaft, as will be described later. Fitting over the outer tapered surface


14


of sleeve


12


is the tapered inner bore


16


of a printing plate cylinder


17


. Conventionally a printing plate, not shown, is mounted on the untapered outer surface


18


of printing plate cylinder


17


. A mounting ring


19


is attached to the outer end of printing plate cylinder


17


by threaded bolts engaged in the threaded openings


20


, see FIG.


5


. The cylinder


17


may be a magnetic cylinder or a type which holds the printing plate in place by mechanical means.




The outer or unattached end of shaft


10


is counter sunk to form a depression or recess identified by reference numeral


22


. Resting in recess


22


is a push/pull block


23


. Preferably recess


22


is cylindrical in shape and push/pull block


23


is in the form of a disk which rests in recess


22


. Disc or block


23


is free to move axially within the recess, within limits, but not circularly or circumferentially. Certain restraints are places on the movement of block or disk


23


as part of the necessary adjustment to bring the printing plate cylinder into correct registration each time the printing plate is changed.





FIG. 5

illustrates greater detail of the cylinder mounting ring


19


. Openings


24


are for threaded bolts which engage threaded openings


20


for attaching the mounting ring to the end of the printing plate cylinder


17


. Slotted openings


25


are access openings for allowing access to bolts which may have to be loosened and then retightened during circumferential adjustment of the printing plate. Slotted opening


26


allows access to adjustment screws which are used for axial adjustment of the printing plate. Slotted opening


27


allows access to an adjustable cam or gear which is used in the circumferential adjustment. The adjustments are done in a conventional and well-known fashion. The central or axial opening


28


is for a threaded bolt for attaching the mounting ring


19


, with the attached printing plate cylinder


17


, to end cap


30


which is attached to sleeve


12


. Threaded opening


38


is merely used for assisting in removing or disengaging the mounting ring with attached printing plate cylinder from sleeve


12


. A screw, not shown, is threaded into opening


38


to make contact with or butt against end cap


30


. As the screw advances it helps dislodge the printing plate cylinder from the sleeve. Opening


39


receives a dowel pin, not shown, which acts as a keyway for aligning mounting ring


19


to end cap


30


when the printing plate cylinder is being placed on sleeve


12


.




As mentioned earlier, the present invention results in benefits usually attributed to a tapered shaft while at the same time achieving benefits of the circumferential and axial adjustments which are normally experienced by using an untapered or a cylindrical shaft. This is achieved by using a sleeve


12


having an untapered bore for engaging an untapered rotatable drive shaft


10


so that the sleeve


12


can be moved slightly as necessary with respect to the shaft to obtain the circumferential and axial adjustments as needed for accurate registration. For removable attachment of printing plate cylinder


17


the outer surface of sleeve


12


is tapered to engage the tapered bore


16


of cylinder


17


. Mounting ring


19


attaches cylinder


17


to end cap


30


which in turn is attached to sleeve


12


whereby moving sleeve


12


circumferentially and/or axially with respect to shaft


10


results in circumferential and/or axial adjustment of cylinder


17


. As described earlier, to change a printing plate, cylinder


17


is removed from sleeve


12


by unthreading the bolt (not shown) in opening


28


of mounting ring


19


and sliding cylinder


17


, with attached mounting ring


19


, off sleeve


12


using a dislodging screw in opening


38


if necessary. A new printing plate is then placed on the printing plate cylinder


17


which is then replaced on sleeve


12


and bolted on. Alternatively, a new or different printing plate cylinder


17


with attached printing plate is slipped over sleeve


12


. In any event, only the printing plate cylinder with its attached printing plate and mounting ring is removed and replaced as compared to the aforementioned Megyesi device in which the entire assembly including the inner sleeve and the outer sleeve and printing plate and adjustment mechanism is removed from the shaft for replacement of the printing plate. Because the components are made of metal, they are quite heavy so to lighten the load the Megyesi components are made out of lighter weight metal such as aluminum or something similar. This can result, and has resulted, in some manufacturing problems, e.g., the aluminum components may not hold tolerances. Since the instant invention requires fewer component parts be removed and replaced when changing printing plates, cylinder


17


and sleeve


12


can be made out of a heavier and stronger metal, such as steel or similar, which hold tolerances more closely thereby achieving a significant manufacturing benefit.




One of the components or elements utilized for adjustment is the push/pull block or disk


23


which rests within the recess


22


at the end of shaft


10


. Referring to

FIG. 3

, push/pull block


23


is attached to the end of shaft


10


by four shouldered bolts inserted through counter-sunk openings


31


. As illustrated in

FIG. 4

, the bolts have a partially threaded length identified by reference


29


to engage corresponding threaded openings in the end of shaft


10


, not shown, and have an unthreaded shoulder


35


which permits push/pull block


23


to move longitudinally or in an axial direction while still attached to shaft


10


. In this fashion, then, push/pull block


23


is attached to shaft


10


yet has some degree of freedom of movement in an axial direction with respect to shaft


10


but cannot rotate or move circularly or in a circumferential direction with respect to shaft


10


. Opening


32


is to accommodate and accept a pin for attaching a cam or gear to make a circumferential adjustment of sleeve


12


with attached cylinder


17


which is done in a conventional fashion. Openings


33


and


34


are utilized for axial adjustment which is also done in a conventional fashion. A bolt or threaded screw, not shown, is threaded through opening


33


and the end of the bolt makes contact with or butts against the end of shaft


10


at the bottom of recess


22


. The other axial adjustment opening


34


contains a screw, not shown, with clearance between opening


34


and the screw but with the screw threaded into a threaded opening, not shown, in the end of shaft


10


. When the bolt in opening


33


is threaded inwardly or advanced it moves push/pull block


23


axially outward or toward the free end of shaft


10


and when the screw in opening


34


is advanced it serves to pull push/pull block


23


inwardly or in the opposite direction toward the attached end of the shaft, i.e., toward the bottom of recess


22


. Push/pull block


23


is linked to sleeve


12


via end cap


30


and printing plate cylinder


17


with attached printing plate is coupled to sleeve


12


via mounting ring


19


so that the printing plate can be adjusted axially as needed to bring it into proper axial registration by axially adjusting push/pull block


23


. The two threaded openings


36


are to receive threaded bolts, not shown, which attach push/pull block


23


to the end cap


30


and thereby transfer the adjustments as described to the printing plate cylinder. Threaded openings


37


are to receive threaded bolts, not shown, for loosely attaching push/pull block


23


to end cap


30


for precaution to prevent the remote possibility of the two becoming disengaged during circumferential adjustment. Opening


46


in push/pull block


23


is merely to provide clearance for the bolt which attaches mounting ring


19


to end cap


30


.




Referring now to

FIG. 2

, end cap


30


is used for attaching push/pull block


23


to sleeve


12


. The seven outer peripheral shouldered openings


40


are for screws or bolts for attaching end cap


30


to the end of sleeve


12


. The central threaded opening


41


is to receive a bolt which passes through opening


28


on mounting ring


19


for attaching the mounting ring, along with the printing plate cylinder


17


, to end cap


30


thereby connecting printing plate cylinder


17


to sleeve


12


. When the printing plate is to be changed the bolt is unthreaded from opening


41


and the mounting ring


19


and printing plate cylinder


17


are slipped off sleeve


12


. An indexing hole


42


receives the dowel pin that fits into opening


39


in mounting ring


19


for alignment purposes when the printing plate cylinder is being placed on sleeve


12


. Slotted openings


43


are for the bolts which thread into openings


36


of push/pull block


23


and slotted openings


44


are for the bolts which thread into openings


37


on push/pull block


23


. Slotted opening


45


provides access to the axial adjustment screws or bolts which are in openings


33


and


34


in push/pull block


23


.



Claims
  • 1. Apparatus for mounting a plate cylinder to a printing press:an elongated untapered cylindrical shaft attached at one end to a source for rotationally driving said shaft; a sleeve having an axial untapered bore for engaging the outer surface of said shaft, said sleeve having a tapered outer surface; a plate cylinder having an untapered cylindrical surface for holding a printing plate and a tapered bore for engaging the outer surface of said sleeve; a recess at the distal end of the shaft; a push/pull member resting in said recess; means coupling said push/pull member to the shaft for axial adjustment of said push/pull member with respect to the shaft; and an end cap coupling said push/pull member to said sleeve for transferring any axial adjustment from said push/pull member to said sleeve.
  • 2. The apparatus as described in claim 1 further including:means for circumferentially adjusting said sleeve with respect to the shaft.
  • 3. The apparatus as described in claim 2 further including a mounting plate attached to an end of said printing plate cylinder; andmeans for attaching said mounting plate to said end cap for ensuring that the axial and circumferential adjustments of said sleeve are transferred to said printing plate cylinder.
  • 4. The apparatus as described in claim 3 wherein said mounting plate has openings for access to said axial and circumferential adjustment means.
US Referenced Citations (11)
Number Name Date Kind
1230190 McIndoe et al. Jun 1917 A
2587606 Dungler Mar 1952 A
3693544 Tryzna Sep 1972 A
3694844 Welter Oct 1972 A
3739722 Zottoli Jun 1973 A
4594068 Bardutzky et al. Jun 1986 A
4864926 Saueressig Sep 1989 A
5195430 Rise Mar 1993 A
5819648 Megyesi Oct 1998 A
5904095 Nelson May 1999 A
5996494 McEarchern Dec 1999 A
Foreign Referenced Citations (1)
Number Date Country
356008264 Jan 1981 JP