Rotary printing machine

Information

  • Patent Grant
  • 6308622
  • Patent Number
    6,308,622
  • Date Filed
    Monday, August 30, 1999
    24 years ago
  • Date Issued
    Tuesday, October 30, 2001
    22 years ago
Abstract
A device for use in a rotary printing machine having at least one printing mechanism including a plate cylinder which can be releasably mounted on a shaft carrying the plate cylinder. The plate cylinder and the shaft can be oriented both axially and also in the peripheral direction relative to the shaft and thus relative to the article to be printed. When the plate cylinder and the shaft are oriented as desired, the plate cylinder is capable of being fixedly attached to the shaft. The plate cylinder can be fixed in the peripheral direction and in the axial direction.
Description




FIELD OF THE INVENTION




The invention concerns a device for use in a rotary printing machine.




BACKGROUND OF THE INVENTION




A typical form of rotary printing machine has at least one printing mechanism including a plate cylinder which can be releasably mounted to a shaft carrying it. The plate cylinder carries a printing plate which is fixedly connected thereto. If the printing plate is provided with the respective print image to be produced, in a special imaging or image-applying apparatus, that is to say outside the printing mechanism itself, it is then necessary for the printing or blanket cylinder, upon being fitted into the printing mechanism, to be properly oriented with respect to the shaft which carries it, in such a way that the print image which is transferred from the printing plate on to the printing cylinder is correctly oriented with respect to the article to which the printing is to be applied and on to which therefore the printing or blanket cylinder transfers the print image. In view of the fact that in many cases the number of articles to which printing is to be applied in the same fashion, that is to say the number of articles constituting a respective batch, may be very low, there is a need for the printing plate to be changed at short intervals of time. If the printing plate is fixedly connected to the plate cylinder, frequent changes in the printing plate entail correspondingly frequent changes in the plate cylinder. The amount of time that this involves is particularly significant when, as is normally always the case in offset printing, the article is to be successively provided with a plurality of partial print images each consisting of different colors or inks, which supplement each other to form an overall print image. This therefore requires a corresponding number of printing mechanisms and accordingly also plate cylinders, in the rotary printing machine.




SUMMARY OF THE INVENTION




An object of the present invention is to provide a rotary printing machine which permits plate cylinder changes to be implemented in a simple fashion involving a minimum amount of time.




Another object of the present invention is to provide a rotary printing machine affording a structure such as to permit accurate adjustment of the respective plate cylinder so as to satisfy the nowadays usual demands in terms of print image quality.




Still a further object of the present invention is to provide a rotary printing machine affording adjustability of plate cylinder and print image such as to satisfy the particularly high demands in terms of accuracy of adjustment which are involved when an article to be provided with printing thereon is to be successively provided with a plurality of partial print images which must be accurately positioned relative to each other.




In accordance with the principals of the present invention the foregoing and other objects are obtained by a rotary printing machine having at least one printing mechanism which includes a plate cylinder which can be releasably mounted on a shaft carrying it. The plate cylinder and the shaft are adapted to as to enable orientation of the plate cylinder relative to its shaft both axially and also in a peripheral direction, and for fixing the plate cylinder to a shaft in an oriented position with respect thereto. The plate cylinder includes a means of positioning which comprises a first and second projection. Associated with the shaft is an adjustment means for adjusting the position of the positioning means enabling the plate cylinder to be positioned as desired. The adjustment means comprises a first and second adjustable bolt. The first projection is co-operable with the first adjustable bolt which is operatively associated with the shaft for fixing the position of the plate cylinder in the peripheral direction. The second projection is co-operable with the second adjustable bolt which is operatively associated with the shaft to fix the axial position of the plate cylinder relative to the shaft. The first and second adjustable bolts include a region against which the respective positioning means come to bear so as to enable convenient and accurate positioning of the plate cylinder in either the peripheral direction or the axial direction.




In accordance with a preferred feature of the invention, operatively associated with the plate cylinder is a collar which is also arranged on the drive shaft thereof and which is provided with the adjustable bolts, while the-first and second projections located on the plate cylinder are introduced into openings in the collar that are brought into contact in the openings with the adjustable bolts which determine the position of the plate cylinder both axially and also in the peripheral direction.




In accordance with a further preferred feature of the invention the use of conically tapering portions of said bolts which are adjustable in the direction of the longitudinal axis thereof affords the advantage that the operating position of the plate cylinder can be very accurately adjusted relative to the shaft by simple axial displacement of the conically tapering portion.




An operating procedure which has been found to be particularly advantageous is one in which the imaging apparatus is also so designed that the positioning of the plate cylinder in the imaging apparatus is in conformity with the positioning thereof in the printing mechanism so that it is only necessary for the imaged plate cylinder to be removed from the imaging apparatus and fitted on to the drive shaft in the printing mechanism, whereupon, using the arrangement according to the invention, orientation thereof can be effected therein, relative to the shaft, without each change in plate cylinder necessitating displacement of the conically tapering portions for the purposes of adjusting the position of the plate cylinder in the axial direction and in the peripheral direction. On the other hand however the invention also permits fast and in particular accurate adjustment of the plate cylinder in a simple fashion in the situations in which the conically tapering portions for determining the position of the plate cylinder on the shaft have to be set for the first time or re-adjusted so that a fast change of the plate cylinders including accurate adjustment thereof is possible even when the position of the plate cylinder in the imaging apparatus is not defined in relation to the position of the plate cylinder in the printing mechanism.




It will be appreciated that it is assumed in all cases that the position of the plate which is respectively carried by the plate cylinder is accurately fixed and defined in relation to the plate cylinder.




Further objects, features and advantages of the invention will be apparent from the following description of a preferred embodiment of the invention.











BRIEF DESCRIPTION OF THE DRAWING





FIG. 1

is a side view of a plate cylinder,





FIG. 2

shows a front view of the

FIG. 1

structure,





FIG. 3

is a side view of a unit comprising a drive shaft, a plate cylinder and associated components,





FIG. 4

shows a view in section taken along line IV—IV in

FIG. 3

,





FIG. 5

shows a view in section taken along line V—V in

FIG. 3

,





FIG. 6

shows a view in section taken along line VI—VI in

FIG. 3

,





FIG. 7

shows a detail from

FIG. 2

on an enlarged scale,





FIG. 8

shows a plan view of the detail in

FIG. 7

, and





FIG. 9

is a view in longitudinal section of the detail of FIG.


7


.











DESCRIPTION OF THE PREFERRED EMBODIMENT




Referring firstly to

FIGS. 1 through 3

, reference numeral


10


denotes a mounting shaft of a printing mechanism of which at least one is contained in a rotary printing machine. The at least one printing mechanism further includes a plate cylinder which is generally indicated at


12


and which is mounted releasably and thus interchangeably on the shaft


10


which carries it. Connected upstream of the plate cylinder


12


in the printing mechanism is an ink roller (not shown). The plate cylinder


12


carries a printing plate (not shown) which has been provided with the appropriate print image to be applied to an article. The ink which is applied to the printing plate by the inking roller is transferred in accordance with the print image on to the printing blanket of the printing or blanket cylinder (not shown) which also forms part of the printing mechanism, and from the blanket on to the article to which the printing is to be applied. It will be appreciated that the arrangements and operating procedures just outlined above are readily familiar to the man skilled in the art for example in connection with offset printing machines so that details thereof do not need to be particularly described herein.




The printing plate which in operation of the printing mechanism is carried on the plate cylinder


12


is provided with the appropriate print image in a separate special image-applying or imaging station, for example by means of a laser. Thereupon the plate cylinder


12


is fitted on to the shaft


10


and secured thereto. As it is necessary for the print image and therewith the printing plate to be oriented in a specifically defined manner with respect to the article to which printing is to be applied, the plate cylinder


12


has to be suitably oriented with respect to the drive and mounting shaft


10


on which it is driven in rotation.




For that purpose, the plate cylinder


12


is provided with a means of positioning adapted to work together with an adjustment means so as to enable the convenient and accurate positioning of the plate cylinder. In a preferred embodiment, the means of positioning includes a first projection


16


and a second projection


18


. The first projection


16


serves to fix the position of the plate cylinder with respect to the shaft in the peripheral direction of the shaft


10


and the plate cylinder


12


. The first projection


16


illustrated in this embodiment is in the form of a cylindrical pin which is inserted in a bore


17


at the one end of the plate cylinder


12


and forms a projection which protrudes with respect to the end face


14


of the plate cylinder


12


. It should be understood however that the pin may be formed in any shape.




The second projection


18


serves for fixing the position of the plate cylinder


12


relative to the shaft


10


in the direction of the longitudinal axis of the shaft


10


or the plate cylinder


12


. The second projection


18


, in a preferred embodiment, is in the form of a T-shaped member indicated at


22


and shown in somewhat greater detail in

FIGS. 7 through 9

. It will be seen from

FIG. 1

however that the second projection


18


projects with respect to the end face


14


of the plate cylinder


12


. The second projection


18


is fixed to the plate cylinder


12


by means of two screws shown in FIG.


1


and indicated at


20


in

FIGS. 2 and 3

, which engage into corresponding screwthreaded bores at the end face


14


of the plate cylinder


12


. The two screws


20


extend through holes


26


provided on the head flange portion


24


of the second projection


18


.




Reference numeral


30


in

FIG. 3

denotes a collar which is disposed on the shaft


10


at a position beside the plate cylinder


12


which is also carried on the shaft


10


, at a small spacing from the end face


14


at which the first and second projections


16


and


18


are disposed. The collar


30


is fixed to the shaft


10


by way of a radial pin indicated at


32


in

FIG. 3

which for fixing purposes is cast using a suitable plastic material in a bore


34


in the collar


30


. The collar


30


is of an annular configuration in cross-section and is provided with two flats which form flat surface portions


36


,


37


extending in mutually right-angled relationship, as can be clearly seen from FIG.


4


.




In the region in which the collar


30


is disposed, the shaft


10


is provided with two substantially radial bores


38


and


40


which can be clearly seen from

FIGS. 4 and 5

. The bores


38


,


40


are displaced relative to each other in the direction of the axial extent of the shaft


10


and extend substantially in right-angled relationship with each other. As can be seen from

FIG. 4

, the first bore


38


is continued at each end into a coaxial bore portion


42


and


43


respectively in the collar


30


, in such a way that the bore


38


in the shaft


20


and the bore portions


42


,


43


in the collar


30


supplement each other to form a continuous means for receiving a first adjusting bolt


48


. In a corresponding manner, the second bore


40


, at each end, is continued into a bore portion


44


and


45


respectively in the collar


30


, in such a way that the second bore


40


and the bore portions


44


,


45


are adapted to receive a second adjusting bolt


50


.




As the two adjusting bolts


48


and


50


are of the same configuration and involve the same mode of operation, only the first adjusting bolt


48


will be described hereinafter.




Referring therefore now to

FIG. 4

, at its end which is towards the flat surface


36


in

FIG. 4

, the first adjusting bolt


48


has a portion


52


which projects with respect to the surface


36


of the collar


30


and which is provided with a first fixedly mounted adjusting knob


56


, by means of which the adjusting bolt


48


can be turned about its longitudinal axis. Adjoining the smaller-diameter bolt portion


52


is a portion indicated at


53


in

FIGS. 4 and 5

and which is provided on its outside with a screwthread engaging with a female screwthread indicated at


55


in Figure, which is provided in the bore portion


43


and in the portion of the bore


38


, that is towards the adjusting knob


56


. Adjoining the screwthreaded portion


53


is a bolt portion


57


without a screwthread, which is guided to achieve an accurate fit in a sleeve or bush indicated at


59


in FIG.


4


. The sleeve or bush


59


is fitted in the region, remote from the adjusting knob


56


, of the bore


38


which is within the shaft


10


. Adjoining the bolt portion


57


is a conically tapering portion


60


which tapers towards the adjusting knob


56


and serves as an abutment. The conical portion


60


continues at its larger-diameter end into a shorter cylindrical bolt portion


61


which is mounted with a close fit, with the interposition of a sleeve or bush


63


, in the bore portion


42


in the collar


30


.




By virtue of the operative engagement between the male screwthread on the bolt portion


53


and the female screwthread portion


55


in the bore


38


in the shaft


10


, rotation of the adjusting bolt


48


about its longitudinal axis, which is effected by turning the adjusting knob


56


, at the same time results in axial displacement thereof with its conical portion


60


, in one direction or the other.




Looking now at FIG.


3


and FIG.


4


. the collar


30


is provided with a first recess or opening


54


which starts from the end face of the collar that faces towards the plate cylinder


12


. This arrangement of the opening


54


can be particularly clearly seen in FIG.


3


. The opening


54


is arranged in such a way that the conical portion


60


of the bolt


48


is disposed within the opening


54


into which, in the assembled condition of the components, the first projection


16


projects to determine the position of the plate cylinder in the peripheral direction relative to the shaft, as can be seen in particular from

FIGS. 1 and 4

. In this respect, the position at which the first projection


16


bears against the conical portion


60


of the bolt


48


(see

FIG. 4

) determines the position of the plate cylinder


12


in the peripheral direction. By virtue of the conical configuration of the bolt portion


60


, axial displacement thereof also results in a corresponding change in position of the first projection


16


and thus the plate cylinder


12


in the peripheral direction so that suitable adjustment of the first adjusting bolt


48


and therewith the conical bolt portion


60


by way of the adjusting knob


56


can determine the position of the plate cylinder


12


in the peripheral direction.




The collar


30


is also provided with a second recess or opening which is indicated at


58


in

FIGS. 4 and 5

and which is arranged to extend continuously through the structure in such a way that the conical portion


65


of the second adjusting bolt


50


is disposed within the second opening


58


. The radial extent thereof can also be slightly greater than the radial extent of the operatively associated conically tapering bolt portion


65


. Adjustment of the second adjusting bolt


50


and therewith the conical bolt portion


65


by way of the second adjusting knob


56


A can determine the position of the plate cylinder


12


in the direction of the longitudinal axis of the shaft


10


.




It will be noted that the extent of each of the two openings


54


and


58


in a plane transverse with respect to the longitudinal axis of the mounting shaft


10


is noticeably larger than the largest diameter of the respective conically tapering bolt portion


60


and


65


respectively.




A prerequisite to achieve the desired orientation of the plate cylinder


12


with respect to the shaft


10


is that, when the plate cylinder


12


is pushed on to the shaft


10


, the two projections


16


,


18


assume a position in the peripheral direction of the collar


30


such that they are disposed in opposite relationship to the respective openings


54


and


58


in the collar


30


and thus engage into the openings. In that respect, it is to be noted that the projection


16


is introduced into the opening


54


at the correct side of the conically tapering bolt portion


60


, for properly establishing the position of the plate cylinder in the peripheral direction. As already indicated above. the axial movement involved in pushing the plate cylinder


12


on to the shaft


10


is limited by the end boundary face


64


encountering the conically tapering portion


65


of the second adjusting bolt


50


, in which case contact between the end face


64


and the conically tapering bolt portion


65


determines the correct position of the plate cylinder


12


. Thereafter, the plate cylinder


12


is turned about the shaft


10


to such an extent with respect to the shaft


10


until the first projection


16


, which in a preferred embodiment is a pin, bears with its peripheral surface


62


against the conically tapering portion


60


of the first adjusting bolt


48


. When that contact occurs, with contact between the second projection


18


and the conical portion


65


of the second adjusting bolt


50


being maintained at the same time, that is a guarantee that the plate cylinder is in the correct position relative to its support shaft


10


.




The above-mentioned rotary movement of the plate cylinder


12


about its shaft


10


, which is normally required for establishing its position in the peripheral direction, also results in a corresponding movement of the projection


18


with respect to the conically tapering bolt portion


65


so that the end face


64


of the second projection


18


, which co-operates with the conically tapering bolt portion


65


, should be of a peripheral extent which is not less than the magnitude of the maximum rotary movement which the plate cylinder experiences in order to bring the first projection


16


into contact with the conically tapering bolt portion


60


associated therewith.




Reference will now be made to the preferred embodiment of the second projection


18


as shown in

FIGS. 8 and 9

.

FIGS. 8 and 9

show more particularly that the second projection


18


is of such a configuration as to be curved around the axis of rotation of the shaft


10


, that is to say it extends in coaxial relationship with that axis of rotation. In that respect, as considered in longitudinal section through the second projection


18


, or more specifically the end portion


66


thereof, the end face


64


is profiled in such a way that along a center circle


68


it has a projection as indicated at


70


in

FIG. 9

, thereby involving substantially punctiform contact between the end face


64


and the conical bolt portion


60


. By virtue of the arcuate configuration of the projection


70


along the circle


68


, the end face of the second projection


18


is always in contact, that is to say irrespective of the position of the second projection


18


in the peripheral direction, with the same point of the conical portion


65


, and thus a movement of the second projection


18


about the axis of rotation of the shaft


10


and the plate cylinder


12


does not result in an axial change in position of the plate cylinder


12


on the shaft


10


.




Associated with each of the two adjusting bolts


48


,


50


is a more or less elastically deformable plastic body as indicated at


67


in

FIG. 4

, which is pressed against the screwthreaded bolt portion


53


by a screw


69


in

FIG. 4

in order thereby to prevent unwanted rotation of the adjusting bolt


48


or


50


respectively and in order thus to secure the adjusting bolt in its set position. On the other hand, possibly after slackening of the screw


69


, there is nonetheless the possibility of adjusting the adjusting bolt


48


or


50


respectively by manually rotating the respective adjusting knob


56


or


56


A in order to adjust the respective conical portion


60


or


65


, in accordance with the desired position for the plate cylinder


12


on its shaft


10


. The screw


69


is carried in a screwthreaded bore within the collar


30


.




After the above-described operation of orienting the plate cylinder


12


with respect to the shaft


10


, the plate cylinder


12


is fixed on the shaft


10


by expansion of the latter. For that purpose, at least in the region in which it carries the plate cylinder


12


, the shaft


10


is of a hollow structure and is filled with a hydraulic fluid. At the end of the shaft


10


which is remote from the two projections


16


,


18


on the plate cylinder


12


, the shaft


10


has a closure screw which is indicated at


74


in

FIG. 3

having a male screwthread engaging into a corresponding female screwthread on the shaft


10


. Actuation of the screw


74


by screwing it into or out of the hollow shaft consequently results in a reduction or an increase in the size of the internal space defined within the hollow shaft


10


and thus results in an increase in or a reduction in the pressure of the hydraulic fluid within the hollow region of the shaft


10


. After the plate cylinder


12


has been moved on to the shaft


10


in the manner described hereinbefore and oriented with respect to the shaft by the action of the two conically tapering bolt portions


60


,


65


, the plate cylinder


12


is fixed on the shaft


10


by suitable actuation of the closure screw


74


in such a way that an increase in the pressure of the hydraulic fluid in the hollow region of the shaft causes the hollow shaft


10


to experience slight radial expansion, by means of which the plate cylinder


12


is suitably fixed on the shaft


10


in the mutually oriented positions thereof. To remove the shaft


10


it is then only necessary to rotate the closure screw


74


in such a way that there is a drop in the pressure of the hydraulic fluid within the shaft


10


and the shaft


10


thus experiences a reduction in diameter by virtue of its elastic nature and the clamping connection to the plate cylinder


12


is thus released.




It will be appreciated that the above-described embodiment of the invention has been set forth solely by way of example and illustration of the principles thereof and that various other modifications and alterations may be made therein without thereby departing from the spirit and scope of the invention.



Claims
  • 1. A device for use in a rotary printing machine having at least one printing mechanism which includes:a shaft having located thereon, a means for adjusting the orientation of a plate cylinder, said means for adjusting including a plurality of adjusting bolts having a conically tapering portion; and a plate cylinder releasably mounted on the shaft, said plate cylinder having a means for positioning; said means for adjusting adapted to engage the means for positioning so as to control the location of the plate cylinder with respect to the shaft, said means for positioning having a plurality of projections in contact with said conically tapering portion so as to adjust the position of the plate cylinder with respect to the shaft.
  • 2. A device as set forth in claim 1 further comprising:a collar fixedly mounted on the shaft beside the plate cylinder and having a side facing towards the plate cylinder, the collar at least at its side towards the plate cylinder including a first opening and a second opening into which a first and second projection extending from said plate cylinder engage in the operative position of the collar and the plate cylinder, wherein a conically tapering portion of a first adjusting bolt is disposed with said first opening and a conically tapering portion of a second adjusting bolt is disposed within said second opening.
  • 3. A device as set forth in claim 2 wherein the shaft and collar are adapted to receive at least one adjusting bolt.
  • 4. A device as set forth in claim 3 wherein the shaft and collar include:a first bore portion in the collar; a radial bore which extends through the shaft and which is coaxial with respect to said first bore portion; a second bore portion in the collar which is coaxial with respect to said first bore portion and said radial bore; and a female screw thread in said radial bore in said shaft, the respectively associated adjusting bolt having a male screw thread co-operating with the associated female screw thread in the bore for adjustment of the position of a respective conically tapering portion located in the axial direction of the adjusting bolt.
  • 5. A device as set forth in claim 4 wherein the conically tapering portion is an inclined portion.
  • 6. A device as set forth in claim 1 wherein a first projection comprises a cylindrical pin having a peripheral surface which in an oriented position of the plate cylinder bears against a conically tapering portion of a first adjusting bolt, and a second projection comprises a T-shaped member having an end remote from the plate cylinder bearing against a conically tapering portion of a second adjusting bolt, said end defining a portion of an arc which is coaxial with the shaft and which is contactable with said conically tapering portion of the second adjusting bolt.
  • 7. A device as set forth in claim 6 wherein said end is provided with a narrow coaxial projection to achieve substantially punctiform contact with said conically tapering portion of the second adjusting bolt.
  • 8. A device for use in a rotary printing machine having at least one printing mechanism which includes:a collar fixedly mounted on a shaft; a plate cylinder releasably mounted on the shaft; a first and second adjusting bolt disposed within said collar; a first and second projection partially disposed within said plate cylinder and extending from the plate cylinder towards the collar; said first projection in contact with a conically tapering portion of said first adjusting bolt so as to enable positioning of the plate cylinder in the peripheral direction; and said second projection in contact with a conically tapering portion of said second adjusting bolt so as to enable positioning of the plate cylinder in the peripheral direction.
  • 9. A device as set forth in claim 8 wherein the collar is flattened at the side of the shaft which is in diametrally opposite relationship to the respective conically tapering portion to afford a flat peripheral surface portion.
  • 10. A device as set forth in claim 8 wherein the conically tapering portion of the adjusting bolts are arranged displaced through about ninety degrees relative to each other.
  • 11. A device as set forth in claim 8 wherein the shaft is hollow at least in the region in which it carries the plate cylinder, and being adapted to increase in diameter upon being subjected to hydraulic pressure exerted from within said hollow region.
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Number Name Date Kind
1328842 Marquardt Jan 1920
3143962 Dobson et al. Aug 1964
3724367 Pasinski Apr 1973
3750568 Weisgerber Aug 1973
4512256 Schriber et al. Apr 1985
5255604 Durr Oct 1993
Foreign Referenced Citations (2)
Number Date Country
2365201 Jun 1975 DE
9113505 Feb 1992 DE