CA2273388C - Positioning device of a flexible printing plate on a plate cylinder - Google Patents
Positioning device of a flexible printing plate on a plate cylinder Download PDFInfo
- Publication number
- CA2273388C CA2273388C CA002273388A CA2273388A CA2273388C CA 2273388 C CA2273388 C CA 2273388C CA 002273388 A CA002273388 A CA 002273388A CA 2273388 A CA2273388 A CA 2273388A CA 2273388 C CA2273388 C CA 2273388C
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- Canada
- Prior art keywords
- plate
- plate cylinder
- claw
- base plate
- cylinder
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41F—PRINTING MACHINES OR PRESSES
- B41F27/00—Devices for attaching printing elements or formes to supports
- B41F27/12—Devices for attaching printing elements or formes to supports for attaching flexible printing formes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41F—PRINTING MACHINES OR PRESSES
- B41F27/00—Devices for attaching printing elements or formes to supports
- B41F27/12—Devices for attaching printing elements or formes to supports for attaching flexible printing formes
- B41F27/1218—Devices for attaching printing elements or formes to supports for attaching flexible printing formes comprising printing plate tensioning devices
- B41F27/1225—Devices for attaching printing elements or formes to supports for attaching flexible printing formes comprising printing plate tensioning devices moving in the printing plate end substantially rectilinearly
- B41F27/1231—Devices for attaching printing elements or formes to supports for attaching flexible printing formes comprising printing plate tensioning devices moving in the printing plate end substantially rectilinearly by translatory motion substantially tangential to support surface
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- Supply, Installation And Extraction Of Printed Sheets Or Plates (AREA)
- Rotary Presses (AREA)
- Mechanical Operated Clutches (AREA)
- Portable Nailing Machines And Staplers (AREA)
- Inking, Control Or Cleaning Of Printing Machines (AREA)
Abstract
The positioning device of a flexible printing plate on a plate cylinder (3) allows to bias a printing plate in a rotary printing machine, the plate cylinder (3), having a rotational axis (2), comprises a groove (1) being disposed in a parallel direction with the rotational axis (2) and inside of which said positioning device of the printing plate is arranged. This device is actuated by the lateral movement of the plate cylinder (3) which is set into operation by an external means and by a cam-ring (14) being arranged outside the cylinder facing this means. This means, which is secured to the frame of the printing machine, consists of the motor and the mechanism allowing the conventional lateral movement of the plate cylinder (3) along its rotational axis (2). On the inner edges (12, 13) of the cam-ring (14) rests, by means of a screw (62) and a fastener (60), a roller secured to a movable base plate which is freely held with respect to the plate cylinder (3) by holding means (102). Two cams (17), being rigidly attached on the bottom of the groove (1) of the plate cylinder (3), control the movement of two rollers (15), which are attached to the base plate (4), in an opposed slanted movement.
Description
' -1-POSITIONING DEVICE OF A FLEXIBLE PRINTING PLATE
ON A PLATE CYLINDER
The present invention relates to a positioning device of a flexible printing plate on a plate cylinder, and more particularly to a device allowing to bias this flexible printing plate on the plate cylinder of a rotary printing machine.
Machines of this kind, which are frequently used in the packaging industry for printing plate-like workpieces such as sheets of paper or cardboard, are usually called flexographic printing machines and comprise a plurality of constitutive stations, i.e. according to a logical development from upstream to downstream referring to the travelling direction of the plate-like workpieces, an infeed station, which successively seizes one sheet after another from the top of a pile, followed by one or more printing groups, if desired, with one or more dryers put in between these groups and, finally, a delivery station collecting the printed workpieces. The sheets are conveyed from one station or one group to another by means of a roller train and a suction system thus entirely setting free the lower printed surfaces of the sheets.
The positioning device of a printing plate is used in the printing groups.
Each printing group, generally printing one colour, comprise a plate cylinder round which winds and is tensioned thereto a flexible printing plate. Being coated with ink owing to a screened cylinder, this printing plate prints at each rotation of the cylinder, according to the number of printing forms that it comprises, one or more patterns on the sheet travelling between the plate cylinder and a pressure roller both arranged such that the printing effects on the tower surface of the sheets.
The printing form, consisting of a rubber or plastic material, is usually glued on a flexible support base made of polyester such as Mylar in order to form an assembly called printing plate. After the manufacturing of the printing form. its gluing onto the polyester base is a decisive operation. Being performed by the manufacturer, it directly conditions the quality of the printing register between the various colours. The upstream and downstream ends of the flexible support base are equipped with a plastic strip, a longitudinal edge of which having an U-section and allows the fixing of the printing plate in a claw secured to the plate cylinder. This claw is arranged in a parallel direction with the rotational axis of this cylinder. A thin metallic plate, attached on the strip and provided with an elongate aperture having a longitudinal upstream-downstream axis, allows a rapid and accurate lateral positioning of the printing plate on its cylinder by fitting on a centering pin secured to the claw.
At the time of gluing the printing form on its flexible support polyester base, a lateral or longitudinal positioning error can easily be corrected, respectively by a lateral movement or by a rotation of the plate cylinder round its axis, but this will not be the case if an error is caused by a biasing of the printing form. Then, the sides of the printing form are not orientated in a parallel or perpendicular direction with the upstream and downstream edges of the polyester base, resulting in an incorrigible biased positioning of the printing form with respect to the direction given by the rotational axis of the plate cylinder.
If a plurality of printing forms are glued on a flexible polyester base, each having the same biasing error, generally the upper edges of each printing form are aligned and can thus be assimilated to a single large printing form affected by a positioning error resulting from a biased positioning.
In order to remedy to this problem, various known devices allow to pivot the front and rear claws with respect to the rotational axis of the plate cylinder so as to bias the printing plate by the same amount but in opposition to the registered error.
To this end, US Patent 5'488'904 describes a device comprising two parallel bars clamping the ends of the printing plate. A mechanism, controlled by the manual rotation of a graduated eccentric gauge, allows to impart a lateral movement (parallel to the rotational axis of the cylinder) to the rear fixing bar of the printing plate and a pivoting of the front bar owing to an assembly of bent pieces articulating round a plurality of pivots arranged at its ends. Owing to an articulation actuated by a spring placed at one end of the rear bar, this latter is automatically pivoted in a position which is parallel to the position occupied by the front bar, when the printing plate is kept by its two ends in this device. The whole mechanism is arranged in the plate cylinder body at the bottom of a wide and deep groove which is machined in a parallel direction with the rotational axis of the cylinder. The eccentric controlling the mechanism is mounted on one side of the plate cylinder.
Patent EP-232'730 provides another biasing device of a printing plate suggesting a mechanism based on the pivoting of two tension bars in which the ends of the printing plate are clamped. The ends of the tension bars are connected to each other by two articulated plates having a triangular shape and being mounted on two fixed pivots which are secured to the plate cylinder.
The pivots of the articulations have a rectangular configuration so that the tension bars of the printing plate pivot about a virtual point P located in the center axis of the plate cylinder. The control means is arranged on one side of the plate cylinder and comprises a complex mechanism consisting of articulated levers which can be actuated by a single-acting cylinder when the plate cylinder is at standstill in a determined position.
Patent JP 62-56146 solves the biasing problem of a printing plate with a device comprising two bars which are each actuated by two hydraulic cylinders. When the position of the printing plate has to be diagonally corrected, the oil pressure in these four hydraulic cylinders is reduced so that four springs, having been compressed by the four hydraulic cylinders, can slacken and force back the fixing bars of the printing plate in an opening movement. The correction value is input to a controller converting it in a corresponding oil pressure applied to two other additional hydraulic cylinders arranged on the same side at one end of the fixing bars. Under the action of these two other hydraulic cylinders, two slanted planes can be independently moved in a rectilinear movement so as to force, when closing the fixing bars of the printing plate, one end of each bar in a perpendicular movement owing to the triangular shape of the slanted plane. In a preferred embodiment, the slanted planes can also be actuated by a motorized screw mechanism.
Several drawbacks arise with these devices, namely - the presence of a so-called enclosed mechanism which is bulky and needs, in the plate cylinder body, the arrangement of a groove having important dimensions with respect to the diameter of the cylinder, the existence of an undesirable unbalance, due to the importance of the arrangement of such a mechanism, generating constraints which originate in the bearings of the cylinder when the latter reaches a certain rotational speed, - a circumferential working surface about the cylinder which is reduced by the important width of the groove that is required by the biasing device, - the presence, in some case, of a manual adjustment which requires a machine stop involving a prolongated adjustment time, - the impossibility to resort to entire automation of adjusting the printing plate when old jobs are to be restarted; for which jobs the adjustment values could have been numerically saved and memorized, - the necessity of controlling the mechanism leading to the biasing of the printing plate, in the case of a non-manual adjustment, by means of an additional actuator being independent of the one which enables the lateral or circumferential movement of the plate cylinder.
The biasing device of a printing plate according to the invention is meant to remedy these drawbacks by providing a simple and automatized means, which occupies only a minimum volume in the plate cylinder body, and with which the machine has not to be stopped. Advantageously, due to the minimum volume occupied, the device is not depending on a biasing mechanism of the printing plate actuated by an actuator arranged in the plate cylinder body. Thus, for driving the biasing mechanism of the printing plate, the device described in the present invention uses an electrical motor secured to the frame of the machine being the same as the motor for moving the plate cylinder for lateral adjustment. This solution allows, on the one hand, a more rational utilization of the actuator that is already provided for lateral adjustment of the printing plate, and, on the other hand, to a biasing mechanism that is less expensive, less bulky, but strong and reliable, and which is easy to adapt to plate cylinders without such mechanism. Finally, owing to this mechanism, the utilization of an external electronic controller, which is connected to a plurality of position sensors arranged outside the cylinder, allows measurement and memorizing of the various adjustment positions adapted to respective jobs which could easily be restarted subsequently without requiring to register them. This latter variant offers an additional asset being particularly suitable for the mechanism of the present invention.
For this purpose, the present invention provides positioning device of a flexible printing plate on a plate cylinder in a printing machine frame, which device allows to bias a printing plate in a rotary printing machine, the plate cylinder, having a rotational axis, comprising a groove which is disposed parallel to the rotational axis and inside which said positioning device of a printing plate is arranged, characterized by the fact that the device is actuated by lateral movement of the plate cylinder, which is set into operation by an external means secured to the frame of the printing machine and by a cam-ring, which is arranged outside the cylinder opposite said external means, said cam ring having inner edges on which rests a roller that secured to a movable base plate which is freely held with respect to the plate cylinder by holding means and by two cams which are rigidly attached on the bottom of the groove of the plate cylinder and which control the movement of two rollers, being attached to the base plate.
-5a-In order to define some expressions used in the present description for describing the position of some elements within the printing machine, it should be understood that the terms "operator's side" (C. C.) and "opposite operator's side" (C.O.C.) make reference to a side as seen from the longitudinal center axis of the machine. This in order to avoid any confusions of the conventional terms left-hand side and right-hand side which depend on the point of view of the observer. In a similar way, for describing the orientation of some axis or means, the usual terms "longitudinal" and "lateral" will be used, still referring to the center axis of the machine, the orientation of which being determined by the travelling direction of the plate-like workpieces. Finally, it should be noted that the terms "upstream" and "downstream" refer to the travelling direction of the plate-like workpieces within the printing machine.
The invention will be better understood by the study of an embodiment taken by way of nonlimiting example and illustrated by the following drawings, in which:
Figs la and 1b are plan views, showing respectively a third C.O.C. and a third C.C. of the biasing device mounted on the plate cylinder, - Fig. 2 is a partial sectional view of the end C.C. of the positioning device of a flexible printing plate on the plate cylinder, - Figs. 3 and 4 are sectional views of the biasing device mounted on the plate cylinder, respectively according to the lines A-A and B-B of Figs.
1a and 1 b, - Figs. 5a and 5b are plan views, showing respectively one half C.O.C.
and one half C.C. of the base plate and the claw support being fitted thereon, - Fig. 6 is, in a parallel direction with the rotational axis of the plate cylinder, a partial sectional view of this cylinder in the vicinity of the cam C.C., - Fig. 7 is a plan view of the cam C.C. and of the corresponding stirrup, - Fig. 8a is a schematical plan view of the biasing device of the printing plate; more particularly when this mechanism is in an intermediate position of non-biasing the printing plate, - Fig. 8b differs from Fig. 8a in that the biasing mechanism of the printing plate, after a clockwise rotation, is acting in a first end position, - Fig. 8c differs from Fig. 8b in that the biasing mechanism of the printing plate, after a anticlockwise rotation, is acting in a second end position.
Figs. 1 a and 1 b are general plan views of the positioning device of a printing plate arranged in a groove 1 machined in a parallel direction with the rotational axis 2 of a plate cylinder 3. As better shown in the corresponding sectional views of Figs. 3 and 4, the biasing device is supported on a base plate 4 on which an immovable front claw 5 is attached, which seizes, in a notch 7, the front edge of a printing plate 19 arranged about the plate cylinder 3. Facing the front claw 5, a movable rear claw 6, which seizes the rear edge of the printing plate 19 in a notch 8, has at its end C.O.C. a slide 9 engaged on a roller 10 screwed on a block 100 secured to the plate cylinder 3 by two fastening screws. At the opposite end of the positioning device (Fig. 2), the base plate 4 is attached to a roller 11, which is placed between the lateral faces 12 and 13 of a circular cam-ring 14 mounted on the frame (not shown) of the machine. As can be seen in Figs. 1 a and 1 b, two other rollers 15, 16 are secured to the base plate 4 and slide respectively in two cams 17 and 18 which are rigidly attached to the bottom of the groove 1 of the plate cylinder 3.
A means 101, consisting of an electrical motor, is mechanically joined with the plate cylinder 3 and allows to laterally move it along its rotational axis 2.
As illustrated in Figs. 1 a, 1 b and 3, the base plate 4 comprises a plurality of supports 20 in the form of rectangular blocks kept at their base by screws 21 and above which are fixed, firstly and by means of screws 23, a protection plate 22 bent in its length, then the front claw 5 kept by screws which also clamp the protection plate 22. Opposite the front claw 5, the rear claw 6 is attached by fastening means 103 (Fig. 4) onto a claw support 25 consisting of a metallic plate having a plurality of elongate apertures 26 (Fig.
5a, 5b) through which are arranged studs 27 allowing to maintain the rear claw 6 on its claw support 25 by means of fastening screws 28. The orientation of these elongate apertures 26 allows for the lateral movement of the claw support 25 with respect to the rear claw 6 and drives this latter in a longitudinal perpendicular movement to the rotational axis 1 of the plate cylinder. The closing and the opening of the rear claw 6 is achieved by this movement which allows respectively to tighten or to liberate the printing plate 19 of the plate cylinder 3. The claw support 25 is rigidly attached by means of screws 29 on two blocks 30 having a cuboidal rectangular form and sliding on two axes 31. These axes are kept at each end by a support 32 attached to the base plate 4 by screws 33. There is a fastening screw 34 above each support for locking the axis 31 in its support 32. Therefore, the claw support 25 can be longitudinally moved along the axes 31 driving the rear claw 6 owing to the perpendicular orientation of the elongate apertures 26.
The longitudinal opening movement of the rear claw 6 is controlled by seven simultaneously working pneumatic cylinders 40 (Fig. 5a, 5b), which are supplied by ducts 41 kept on the base plate 4 by fastening clamps 42, and which are attached to each other by connections 43. These pneumatic cylinders 40 are mounted by screws 45 on L-shaped supports 44, which may also serve as fastening points for the protection plate 22 and the front claw 7.
These supports 44 are spaced at regular intervals and each positioned on _g_ the base plate 4 by two fastening screws. Plates 46, which are bent at right angles in their ends, are positioned facing the pneumatic cylinders 40 and welded, standing on one of their two main edges, to the claw support 25.
During pressurization of the pneumatic circuit supplying the pneumatic cylinders 40, the axes 47 of these pneumatic cylinders (Fig. 1 a, 1 b), resting on the plates 46, push the claw support 25 in front of them. The rear claw 6, associated with the claw support 25, is then opened.
The closing of the rear claw 6 is achieved, after having released the pessure in the pneumatic cylinders, by a plurality of compression springs 48 pushing back.the claw support 25 in a longitudinal closing movement. Each spring 48 is guided by thestem of a screw 49 extending through the bent plate 46 on which rests one end of these springs. The second end of the springs 48 rests on a plug 50 which is screwed in a retaining block 51 that is kept on the base plate 4 by two screws 52. The retaining blocks 51 also serve as fixing support to a second bent protection plate 53 which partially covers the top of the claw support 25. This protection plate 53 is attached to its base by a plurality of screws 54 (Fig. 1 a, 1 b) arranged in the retaining blocks 51, and has circular openings to receive the plugs 50.
The lateral positioning of the printing plate 19 on the front claw 5 is ensured by a centering pin 55 (Fig. 4) chased in the upper part of the front claw 5 and accurately arranged on the longitudinal axis of the printing machine.
Fig. 5b shows a fastener 60 attached to the end C.C. of the base plate 4 by screws 61. The roller 11 is positioned on the longitudinal axis of this fastener by means of a screw 62. Two openings 63 in the vicinity of the first and the last third of the base plate 4 have a diameter which is substantially greater than the diameter of two bushings 64 extending through them (Fig. 3).
The overdimension of the openings 63 allows to provide the place required by the movements of the base plate 4 while being flattened at the bottom of the groove 1 by holding means 102; this in order to control the action of the centrifugal force on the base plate 4 during rotation of the plate cylinder.
The holding means 102 consist of bushings 84 round which two bearing shells 65, which are made of synthefical material having tow coeffiGent of friction, seize 3ondwichod the base plate 4 enabling it to move e~sily. A compression spring 66, being arrangi~d between two other wnsttars 67 and 68, and a screw 89, rusting on thv upper washer 88 and, after having extended through the bushing 64, screwing tn the hattom at the groove t, maintain the clamping of the base plate 4 in a parallel plan to the section of the plate cylinder. The fastener 60 also has an opening 70 through which extends a screw 71, both having the same respective functions as the openings 63 and the 3erows 69 described herein6efore.
As shown in Figs. 5a and 5b, two nclanguiat openings 72, cut out in the base plate 4, allow t0 housA fhA spaced cams 17 and 18 secured to the plate eyllndAr 3. These openings 72 have a larger size than the dirndnsion of the bases 80 of the cams 17 and 18, this for irr~e 'movement of the base plate 4 round these rams without abutting against one of them. The openings 72 aro widthwise bordered at each side with three aligned openings, the center opening9 79 of which allow to accun~ly position a stirrup 74 by means of two cylindrical pins 75, and the and openings 76 of which are adapted to fix the stirrup 74 on the base plate 4 by screws 77. A.s ilustrated in Figs. 6 and 7, the stirrups 74 constitute twe bridges, which are secured to the base plate and arranged above the cams 16 and 17, and in the largest surface of which are screwed from below the rollers 15 and 16 which slide in the respective cams 17 and 18. Screws 78 further allow to fhc the protection plate 22 and the front claw 5 above tire stimrp 74.
The cams 1 B and 17 aro symmetrical one with regard to the other and consist of a stairtike tease 80 being provided, on the one hand, with an opening adapted to receive a centering pin 81 and, on the other hand, with two fixing openings 83 in which slide two screws 82 which are screwed in the plate cylinder 3. Above thin base 80 rise two small salient parts 84 having N
triangular shape end constituting the core of the cams, betwaan which slides the roller 15 or 16.
In order to well grasp the working principle of the mechanism of the present invention, Figs. 8a, 8b and 8c schematically illustrate three different positions which can be occupied by the positioning device of the printing plate.
If no biasing is applied to the printing plate, the configuration of the mechanism is in an intermediate position corresponding to the schematical illustration of Fig. 8a.
If the printing plate has to be biased in one direction or another, a simple lateral movement of the plate cylinder in the direction of its rotational axis 2 allows to actuate the biasing mechanism of the printing plate. The lateral movement of the plate cylinder 3 is controlled by the means 101 comprising an electrical motor coupled to toothed wheels gearing in a worm.
This conventional mechanism allows to convert the circular movement of the motor shaft into a rectilinear movement required by the lateral movement of the plate cylinder. The movement of the plate cylinder by means of the motor and this mechanism is moreover automatized owing to sensors detecting the lateral position of the plate cylinder. These sensors are connected to an external electronic controller (not shown) controlling the motor of the means 101. Thus for a given job, the biasing of a printing plate can easily be controlled and memorized by the electronic controller, via position sensors, by simple memorization of the lateral movement of the plate cylinder.
As illustrated in Fig. 8b, when the cylinder is moved from C.O.C. to C.C., the roller 11 rests, after a certain stroke, against the lateral side 12 of the cam-ring 14. It follows a combined movement of the base plate 4, guided by the rollers 15 and 16 which slide in the cams 17 and 18, consisting of both a pivoting of the base plate 4 round the roller 11 and a translation of this base plate marked by the sliding motion upwards of this roller 11 along the lateral side 12 of the cam-ring 14. The slide 9 of the rear claw 6, which only slides longitudinally on the roller 10, solely permits a movement of translation and rotation round the fixed pivot point consisting of this roller 10 secured to the plate cylinder 3. Due to the longitudinal orientation of this slide, no movement along the axis 2 can be transmitted to the rear claw 6. Therefore, owing to this rear claw 6, which is not movable in a parallel direction with the axis 2 of the plate cylinder, and owing to the combined movement to which the front claw 5 is also liable, the front and rear edges of the printing plate can be biased, as subtly as simply, in a shearing movement while remaining parallel to each other.
Fig. 8c illustrates, in the opposite direction, the same combined movement resulting from the movement of the plate cylinder 3 from C.C. to C.O.C. In this case, the roller 11 rests and slides along the opposite lateral side 13 of the cam-ring 14.
To correct the biased positioning of a printing plate 19, the operator acts on a control which slightly releases the pressure in the pneumatic cylinders 40, so as to slacken and unglue the printing plate from the plate cylinder, and which actuates the motor of the means 101 in order to move, in one direction or another, the plate cylinder 3. Once the roller 11, being in contact with one lateral side 12 or 13 of the cam-ring 14, has moved along this cam-ring 14 by a distance corresponding to the desired biasing, the plate cylinder 3 moves in the opposite direction so as to reposition it according to the lateral register suitable for the printing. The latter movement does not at all change the biasing of the printing plate 19 since, on this opposite movement, the roller 11 is immediately loosened from the lateral side of the cam-ring 14.
Owing to the adherence of the printing plate tensioned on the plate cylinder, the biased positon of the printing plate remains. The position of the lateral register of the plate cylinder being known, it is thus easy to autmatize the baising of the printing plate by an angular value, if desired, by simple introduction of this value in the electronic controller.
Thus, the positioning and biasing operations of a printing plate on a plate cylinder equipped with a device according to the present invention, are limited to the following steps a) Opening of the rear claw 6 by means of the pneumatic cylinders 40 which compress the springs 48.
b) Fixing of the front edge of the printing plate 19 in the notch 7 of the front claw 5 and in the centering pin 55.
c) Slow rotation of the plate cylinder 3 round its axis 2 so that the printing plate 19 winds about the cylinder.
d) Fixing of the rear edge of the printing plate 19 in the notch 8 of the rear claw 6.
e) Closing of the rear claw 6 by releasing of the pressure in the pneumatic cylinders 40.
f) Rapid rotation of the plate cylinder 3 and actuation of the pneumatic cylinders 40 to slightly unglue the printing plate 19 from the cylinder in order to allow for its biasing.
g) Actuation of the biasing of the printing plate 19 by lateral movement of the plate cylinder 3 by a certain distance corresponding to the desired slant.
h) Opposed lateral movement of the plate cylinder 3 so as to restore the lateral register required for the printing.
i) Releasing of the pressure in the pneumatic cylinders 40.
Besides the fixing of the printing plate about its cylinder, each other operation described hereinbefore can easily be automatized owing to the conception and the specific mechanism for biasing the printing plate of the present invention. When restarting an old printing job, advantageously, this device does not require any manual adjustment of the printing plate if the previously known adjustment values have been memorized. Finally, it should be noted that this device also allows a biasing of the printing plate when the plate cylinder rotates at maximum speed. Therefore, the printing machine does not have to be stopped to correct the slanted position of the printing plate, which fact allows to mainly reduce the costs for putting into service when preparing a new printing job. Numerous improvements can be added to this device within the scope of the claims.
ON A PLATE CYLINDER
The present invention relates to a positioning device of a flexible printing plate on a plate cylinder, and more particularly to a device allowing to bias this flexible printing plate on the plate cylinder of a rotary printing machine.
Machines of this kind, which are frequently used in the packaging industry for printing plate-like workpieces such as sheets of paper or cardboard, are usually called flexographic printing machines and comprise a plurality of constitutive stations, i.e. according to a logical development from upstream to downstream referring to the travelling direction of the plate-like workpieces, an infeed station, which successively seizes one sheet after another from the top of a pile, followed by one or more printing groups, if desired, with one or more dryers put in between these groups and, finally, a delivery station collecting the printed workpieces. The sheets are conveyed from one station or one group to another by means of a roller train and a suction system thus entirely setting free the lower printed surfaces of the sheets.
The positioning device of a printing plate is used in the printing groups.
Each printing group, generally printing one colour, comprise a plate cylinder round which winds and is tensioned thereto a flexible printing plate. Being coated with ink owing to a screened cylinder, this printing plate prints at each rotation of the cylinder, according to the number of printing forms that it comprises, one or more patterns on the sheet travelling between the plate cylinder and a pressure roller both arranged such that the printing effects on the tower surface of the sheets.
The printing form, consisting of a rubber or plastic material, is usually glued on a flexible support base made of polyester such as Mylar in order to form an assembly called printing plate. After the manufacturing of the printing form. its gluing onto the polyester base is a decisive operation. Being performed by the manufacturer, it directly conditions the quality of the printing register between the various colours. The upstream and downstream ends of the flexible support base are equipped with a plastic strip, a longitudinal edge of which having an U-section and allows the fixing of the printing plate in a claw secured to the plate cylinder. This claw is arranged in a parallel direction with the rotational axis of this cylinder. A thin metallic plate, attached on the strip and provided with an elongate aperture having a longitudinal upstream-downstream axis, allows a rapid and accurate lateral positioning of the printing plate on its cylinder by fitting on a centering pin secured to the claw.
At the time of gluing the printing form on its flexible support polyester base, a lateral or longitudinal positioning error can easily be corrected, respectively by a lateral movement or by a rotation of the plate cylinder round its axis, but this will not be the case if an error is caused by a biasing of the printing form. Then, the sides of the printing form are not orientated in a parallel or perpendicular direction with the upstream and downstream edges of the polyester base, resulting in an incorrigible biased positioning of the printing form with respect to the direction given by the rotational axis of the plate cylinder.
If a plurality of printing forms are glued on a flexible polyester base, each having the same biasing error, generally the upper edges of each printing form are aligned and can thus be assimilated to a single large printing form affected by a positioning error resulting from a biased positioning.
In order to remedy to this problem, various known devices allow to pivot the front and rear claws with respect to the rotational axis of the plate cylinder so as to bias the printing plate by the same amount but in opposition to the registered error.
To this end, US Patent 5'488'904 describes a device comprising two parallel bars clamping the ends of the printing plate. A mechanism, controlled by the manual rotation of a graduated eccentric gauge, allows to impart a lateral movement (parallel to the rotational axis of the cylinder) to the rear fixing bar of the printing plate and a pivoting of the front bar owing to an assembly of bent pieces articulating round a plurality of pivots arranged at its ends. Owing to an articulation actuated by a spring placed at one end of the rear bar, this latter is automatically pivoted in a position which is parallel to the position occupied by the front bar, when the printing plate is kept by its two ends in this device. The whole mechanism is arranged in the plate cylinder body at the bottom of a wide and deep groove which is machined in a parallel direction with the rotational axis of the cylinder. The eccentric controlling the mechanism is mounted on one side of the plate cylinder.
Patent EP-232'730 provides another biasing device of a printing plate suggesting a mechanism based on the pivoting of two tension bars in which the ends of the printing plate are clamped. The ends of the tension bars are connected to each other by two articulated plates having a triangular shape and being mounted on two fixed pivots which are secured to the plate cylinder.
The pivots of the articulations have a rectangular configuration so that the tension bars of the printing plate pivot about a virtual point P located in the center axis of the plate cylinder. The control means is arranged on one side of the plate cylinder and comprises a complex mechanism consisting of articulated levers which can be actuated by a single-acting cylinder when the plate cylinder is at standstill in a determined position.
Patent JP 62-56146 solves the biasing problem of a printing plate with a device comprising two bars which are each actuated by two hydraulic cylinders. When the position of the printing plate has to be diagonally corrected, the oil pressure in these four hydraulic cylinders is reduced so that four springs, having been compressed by the four hydraulic cylinders, can slacken and force back the fixing bars of the printing plate in an opening movement. The correction value is input to a controller converting it in a corresponding oil pressure applied to two other additional hydraulic cylinders arranged on the same side at one end of the fixing bars. Under the action of these two other hydraulic cylinders, two slanted planes can be independently moved in a rectilinear movement so as to force, when closing the fixing bars of the printing plate, one end of each bar in a perpendicular movement owing to the triangular shape of the slanted plane. In a preferred embodiment, the slanted planes can also be actuated by a motorized screw mechanism.
Several drawbacks arise with these devices, namely - the presence of a so-called enclosed mechanism which is bulky and needs, in the plate cylinder body, the arrangement of a groove having important dimensions with respect to the diameter of the cylinder, the existence of an undesirable unbalance, due to the importance of the arrangement of such a mechanism, generating constraints which originate in the bearings of the cylinder when the latter reaches a certain rotational speed, - a circumferential working surface about the cylinder which is reduced by the important width of the groove that is required by the biasing device, - the presence, in some case, of a manual adjustment which requires a machine stop involving a prolongated adjustment time, - the impossibility to resort to entire automation of adjusting the printing plate when old jobs are to be restarted; for which jobs the adjustment values could have been numerically saved and memorized, - the necessity of controlling the mechanism leading to the biasing of the printing plate, in the case of a non-manual adjustment, by means of an additional actuator being independent of the one which enables the lateral or circumferential movement of the plate cylinder.
The biasing device of a printing plate according to the invention is meant to remedy these drawbacks by providing a simple and automatized means, which occupies only a minimum volume in the plate cylinder body, and with which the machine has not to be stopped. Advantageously, due to the minimum volume occupied, the device is not depending on a biasing mechanism of the printing plate actuated by an actuator arranged in the plate cylinder body. Thus, for driving the biasing mechanism of the printing plate, the device described in the present invention uses an electrical motor secured to the frame of the machine being the same as the motor for moving the plate cylinder for lateral adjustment. This solution allows, on the one hand, a more rational utilization of the actuator that is already provided for lateral adjustment of the printing plate, and, on the other hand, to a biasing mechanism that is less expensive, less bulky, but strong and reliable, and which is easy to adapt to plate cylinders without such mechanism. Finally, owing to this mechanism, the utilization of an external electronic controller, which is connected to a plurality of position sensors arranged outside the cylinder, allows measurement and memorizing of the various adjustment positions adapted to respective jobs which could easily be restarted subsequently without requiring to register them. This latter variant offers an additional asset being particularly suitable for the mechanism of the present invention.
For this purpose, the present invention provides positioning device of a flexible printing plate on a plate cylinder in a printing machine frame, which device allows to bias a printing plate in a rotary printing machine, the plate cylinder, having a rotational axis, comprising a groove which is disposed parallel to the rotational axis and inside which said positioning device of a printing plate is arranged, characterized by the fact that the device is actuated by lateral movement of the plate cylinder, which is set into operation by an external means secured to the frame of the printing machine and by a cam-ring, which is arranged outside the cylinder opposite said external means, said cam ring having inner edges on which rests a roller that secured to a movable base plate which is freely held with respect to the plate cylinder by holding means and by two cams which are rigidly attached on the bottom of the groove of the plate cylinder and which control the movement of two rollers, being attached to the base plate.
-5a-In order to define some expressions used in the present description for describing the position of some elements within the printing machine, it should be understood that the terms "operator's side" (C. C.) and "opposite operator's side" (C.O.C.) make reference to a side as seen from the longitudinal center axis of the machine. This in order to avoid any confusions of the conventional terms left-hand side and right-hand side which depend on the point of view of the observer. In a similar way, for describing the orientation of some axis or means, the usual terms "longitudinal" and "lateral" will be used, still referring to the center axis of the machine, the orientation of which being determined by the travelling direction of the plate-like workpieces. Finally, it should be noted that the terms "upstream" and "downstream" refer to the travelling direction of the plate-like workpieces within the printing machine.
The invention will be better understood by the study of an embodiment taken by way of nonlimiting example and illustrated by the following drawings, in which:
Figs la and 1b are plan views, showing respectively a third C.O.C. and a third C.C. of the biasing device mounted on the plate cylinder, - Fig. 2 is a partial sectional view of the end C.C. of the positioning device of a flexible printing plate on the plate cylinder, - Figs. 3 and 4 are sectional views of the biasing device mounted on the plate cylinder, respectively according to the lines A-A and B-B of Figs.
1a and 1 b, - Figs. 5a and 5b are plan views, showing respectively one half C.O.C.
and one half C.C. of the base plate and the claw support being fitted thereon, - Fig. 6 is, in a parallel direction with the rotational axis of the plate cylinder, a partial sectional view of this cylinder in the vicinity of the cam C.C., - Fig. 7 is a plan view of the cam C.C. and of the corresponding stirrup, - Fig. 8a is a schematical plan view of the biasing device of the printing plate; more particularly when this mechanism is in an intermediate position of non-biasing the printing plate, - Fig. 8b differs from Fig. 8a in that the biasing mechanism of the printing plate, after a clockwise rotation, is acting in a first end position, - Fig. 8c differs from Fig. 8b in that the biasing mechanism of the printing plate, after a anticlockwise rotation, is acting in a second end position.
Figs. 1 a and 1 b are general plan views of the positioning device of a printing plate arranged in a groove 1 machined in a parallel direction with the rotational axis 2 of a plate cylinder 3. As better shown in the corresponding sectional views of Figs. 3 and 4, the biasing device is supported on a base plate 4 on which an immovable front claw 5 is attached, which seizes, in a notch 7, the front edge of a printing plate 19 arranged about the plate cylinder 3. Facing the front claw 5, a movable rear claw 6, which seizes the rear edge of the printing plate 19 in a notch 8, has at its end C.O.C. a slide 9 engaged on a roller 10 screwed on a block 100 secured to the plate cylinder 3 by two fastening screws. At the opposite end of the positioning device (Fig. 2), the base plate 4 is attached to a roller 11, which is placed between the lateral faces 12 and 13 of a circular cam-ring 14 mounted on the frame (not shown) of the machine. As can be seen in Figs. 1 a and 1 b, two other rollers 15, 16 are secured to the base plate 4 and slide respectively in two cams 17 and 18 which are rigidly attached to the bottom of the groove 1 of the plate cylinder 3.
A means 101, consisting of an electrical motor, is mechanically joined with the plate cylinder 3 and allows to laterally move it along its rotational axis 2.
As illustrated in Figs. 1 a, 1 b and 3, the base plate 4 comprises a plurality of supports 20 in the form of rectangular blocks kept at their base by screws 21 and above which are fixed, firstly and by means of screws 23, a protection plate 22 bent in its length, then the front claw 5 kept by screws which also clamp the protection plate 22. Opposite the front claw 5, the rear claw 6 is attached by fastening means 103 (Fig. 4) onto a claw support 25 consisting of a metallic plate having a plurality of elongate apertures 26 (Fig.
5a, 5b) through which are arranged studs 27 allowing to maintain the rear claw 6 on its claw support 25 by means of fastening screws 28. The orientation of these elongate apertures 26 allows for the lateral movement of the claw support 25 with respect to the rear claw 6 and drives this latter in a longitudinal perpendicular movement to the rotational axis 1 of the plate cylinder. The closing and the opening of the rear claw 6 is achieved by this movement which allows respectively to tighten or to liberate the printing plate 19 of the plate cylinder 3. The claw support 25 is rigidly attached by means of screws 29 on two blocks 30 having a cuboidal rectangular form and sliding on two axes 31. These axes are kept at each end by a support 32 attached to the base plate 4 by screws 33. There is a fastening screw 34 above each support for locking the axis 31 in its support 32. Therefore, the claw support 25 can be longitudinally moved along the axes 31 driving the rear claw 6 owing to the perpendicular orientation of the elongate apertures 26.
The longitudinal opening movement of the rear claw 6 is controlled by seven simultaneously working pneumatic cylinders 40 (Fig. 5a, 5b), which are supplied by ducts 41 kept on the base plate 4 by fastening clamps 42, and which are attached to each other by connections 43. These pneumatic cylinders 40 are mounted by screws 45 on L-shaped supports 44, which may also serve as fastening points for the protection plate 22 and the front claw 7.
These supports 44 are spaced at regular intervals and each positioned on _g_ the base plate 4 by two fastening screws. Plates 46, which are bent at right angles in their ends, are positioned facing the pneumatic cylinders 40 and welded, standing on one of their two main edges, to the claw support 25.
During pressurization of the pneumatic circuit supplying the pneumatic cylinders 40, the axes 47 of these pneumatic cylinders (Fig. 1 a, 1 b), resting on the plates 46, push the claw support 25 in front of them. The rear claw 6, associated with the claw support 25, is then opened.
The closing of the rear claw 6 is achieved, after having released the pessure in the pneumatic cylinders, by a plurality of compression springs 48 pushing back.the claw support 25 in a longitudinal closing movement. Each spring 48 is guided by thestem of a screw 49 extending through the bent plate 46 on which rests one end of these springs. The second end of the springs 48 rests on a plug 50 which is screwed in a retaining block 51 that is kept on the base plate 4 by two screws 52. The retaining blocks 51 also serve as fixing support to a second bent protection plate 53 which partially covers the top of the claw support 25. This protection plate 53 is attached to its base by a plurality of screws 54 (Fig. 1 a, 1 b) arranged in the retaining blocks 51, and has circular openings to receive the plugs 50.
The lateral positioning of the printing plate 19 on the front claw 5 is ensured by a centering pin 55 (Fig. 4) chased in the upper part of the front claw 5 and accurately arranged on the longitudinal axis of the printing machine.
Fig. 5b shows a fastener 60 attached to the end C.C. of the base plate 4 by screws 61. The roller 11 is positioned on the longitudinal axis of this fastener by means of a screw 62. Two openings 63 in the vicinity of the first and the last third of the base plate 4 have a diameter which is substantially greater than the diameter of two bushings 64 extending through them (Fig. 3).
The overdimension of the openings 63 allows to provide the place required by the movements of the base plate 4 while being flattened at the bottom of the groove 1 by holding means 102; this in order to control the action of the centrifugal force on the base plate 4 during rotation of the plate cylinder.
The holding means 102 consist of bushings 84 round which two bearing shells 65, which are made of synthefical material having tow coeffiGent of friction, seize 3ondwichod the base plate 4 enabling it to move e~sily. A compression spring 66, being arrangi~d between two other wnsttars 67 and 68, and a screw 89, rusting on thv upper washer 88 and, after having extended through the bushing 64, screwing tn the hattom at the groove t, maintain the clamping of the base plate 4 in a parallel plan to the section of the plate cylinder. The fastener 60 also has an opening 70 through which extends a screw 71, both having the same respective functions as the openings 63 and the 3erows 69 described herein6efore.
As shown in Figs. 5a and 5b, two nclanguiat openings 72, cut out in the base plate 4, allow t0 housA fhA spaced cams 17 and 18 secured to the plate eyllndAr 3. These openings 72 have a larger size than the dirndnsion of the bases 80 of the cams 17 and 18, this for irr~e 'movement of the base plate 4 round these rams without abutting against one of them. The openings 72 aro widthwise bordered at each side with three aligned openings, the center opening9 79 of which allow to accun~ly position a stirrup 74 by means of two cylindrical pins 75, and the and openings 76 of which are adapted to fix the stirrup 74 on the base plate 4 by screws 77. A.s ilustrated in Figs. 6 and 7, the stirrups 74 constitute twe bridges, which are secured to the base plate and arranged above the cams 16 and 17, and in the largest surface of which are screwed from below the rollers 15 and 16 which slide in the respective cams 17 and 18. Screws 78 further allow to fhc the protection plate 22 and the front claw 5 above tire stimrp 74.
The cams 1 B and 17 aro symmetrical one with regard to the other and consist of a stairtike tease 80 being provided, on the one hand, with an opening adapted to receive a centering pin 81 and, on the other hand, with two fixing openings 83 in which slide two screws 82 which are screwed in the plate cylinder 3. Above thin base 80 rise two small salient parts 84 having N
triangular shape end constituting the core of the cams, betwaan which slides the roller 15 or 16.
In order to well grasp the working principle of the mechanism of the present invention, Figs. 8a, 8b and 8c schematically illustrate three different positions which can be occupied by the positioning device of the printing plate.
If no biasing is applied to the printing plate, the configuration of the mechanism is in an intermediate position corresponding to the schematical illustration of Fig. 8a.
If the printing plate has to be biased in one direction or another, a simple lateral movement of the plate cylinder in the direction of its rotational axis 2 allows to actuate the biasing mechanism of the printing plate. The lateral movement of the plate cylinder 3 is controlled by the means 101 comprising an electrical motor coupled to toothed wheels gearing in a worm.
This conventional mechanism allows to convert the circular movement of the motor shaft into a rectilinear movement required by the lateral movement of the plate cylinder. The movement of the plate cylinder by means of the motor and this mechanism is moreover automatized owing to sensors detecting the lateral position of the plate cylinder. These sensors are connected to an external electronic controller (not shown) controlling the motor of the means 101. Thus for a given job, the biasing of a printing plate can easily be controlled and memorized by the electronic controller, via position sensors, by simple memorization of the lateral movement of the plate cylinder.
As illustrated in Fig. 8b, when the cylinder is moved from C.O.C. to C.C., the roller 11 rests, after a certain stroke, against the lateral side 12 of the cam-ring 14. It follows a combined movement of the base plate 4, guided by the rollers 15 and 16 which slide in the cams 17 and 18, consisting of both a pivoting of the base plate 4 round the roller 11 and a translation of this base plate marked by the sliding motion upwards of this roller 11 along the lateral side 12 of the cam-ring 14. The slide 9 of the rear claw 6, which only slides longitudinally on the roller 10, solely permits a movement of translation and rotation round the fixed pivot point consisting of this roller 10 secured to the plate cylinder 3. Due to the longitudinal orientation of this slide, no movement along the axis 2 can be transmitted to the rear claw 6. Therefore, owing to this rear claw 6, which is not movable in a parallel direction with the axis 2 of the plate cylinder, and owing to the combined movement to which the front claw 5 is also liable, the front and rear edges of the printing plate can be biased, as subtly as simply, in a shearing movement while remaining parallel to each other.
Fig. 8c illustrates, in the opposite direction, the same combined movement resulting from the movement of the plate cylinder 3 from C.C. to C.O.C. In this case, the roller 11 rests and slides along the opposite lateral side 13 of the cam-ring 14.
To correct the biased positioning of a printing plate 19, the operator acts on a control which slightly releases the pressure in the pneumatic cylinders 40, so as to slacken and unglue the printing plate from the plate cylinder, and which actuates the motor of the means 101 in order to move, in one direction or another, the plate cylinder 3. Once the roller 11, being in contact with one lateral side 12 or 13 of the cam-ring 14, has moved along this cam-ring 14 by a distance corresponding to the desired biasing, the plate cylinder 3 moves in the opposite direction so as to reposition it according to the lateral register suitable for the printing. The latter movement does not at all change the biasing of the printing plate 19 since, on this opposite movement, the roller 11 is immediately loosened from the lateral side of the cam-ring 14.
Owing to the adherence of the printing plate tensioned on the plate cylinder, the biased positon of the printing plate remains. The position of the lateral register of the plate cylinder being known, it is thus easy to autmatize the baising of the printing plate by an angular value, if desired, by simple introduction of this value in the electronic controller.
Thus, the positioning and biasing operations of a printing plate on a plate cylinder equipped with a device according to the present invention, are limited to the following steps a) Opening of the rear claw 6 by means of the pneumatic cylinders 40 which compress the springs 48.
b) Fixing of the front edge of the printing plate 19 in the notch 7 of the front claw 5 and in the centering pin 55.
c) Slow rotation of the plate cylinder 3 round its axis 2 so that the printing plate 19 winds about the cylinder.
d) Fixing of the rear edge of the printing plate 19 in the notch 8 of the rear claw 6.
e) Closing of the rear claw 6 by releasing of the pressure in the pneumatic cylinders 40.
f) Rapid rotation of the plate cylinder 3 and actuation of the pneumatic cylinders 40 to slightly unglue the printing plate 19 from the cylinder in order to allow for its biasing.
g) Actuation of the biasing of the printing plate 19 by lateral movement of the plate cylinder 3 by a certain distance corresponding to the desired slant.
h) Opposed lateral movement of the plate cylinder 3 so as to restore the lateral register required for the printing.
i) Releasing of the pressure in the pneumatic cylinders 40.
Besides the fixing of the printing plate about its cylinder, each other operation described hereinbefore can easily be automatized owing to the conception and the specific mechanism for biasing the printing plate of the present invention. When restarting an old printing job, advantageously, this device does not require any manual adjustment of the printing plate if the previously known adjustment values have been memorized. Finally, it should be noted that this device also allows a biasing of the printing plate when the plate cylinder rotates at maximum speed. Therefore, the printing machine does not have to be stopped to correct the slanted position of the printing plate, which fact allows to mainly reduce the costs for putting into service when preparing a new printing job. Numerous improvements can be added to this device within the scope of the claims.
Claims (10)
1. Positioning device of a flexible printing plate (19) on a plate cylinder (3) in a printing machine frame, which device allows to bias a printing plate in a rotary printing machine, the plate cylinder (3), having a rotational axis (2), comprising a groove (1) which is disposed parallel to the rotational axis (2) and inside which said positioning device of a printing plate is arranged, characterized by the fact that the device is actuated by lateral movement of the plate cylinder (3), which is set into operation by an external means (101) secured to the frame of the printing machine and by a cam-ring (14), which is arranged outside the cylinder opposite said external means (101), said cam-ring having inner edges (12, 13) on which rests a roller (11) that secured to a movable base plate (4) which is freely held with respect to the plate cylinder (3) by holding means (102) and by two cams (17, 18) which are rigidly attached on the bottom of the groove (1) of the plate cylinder (3) and which control the movement of two rollers (15, 16), being attached to the base plate (4).
2. Device according to claim 1, characterized by the fact that the external means (101) of setting into operation of the positioning device of the printing plate consists of a motor and a mechanism allowing the conventional lateral movement of the plate cylinder (3) along its rotational axis (2) and of a numerical controller adapted to measure and to memorize the value and the direction of lateral movements of the plate cylinder utilizing conventional sensors arranged in the frame of the printing machine.
3. Device according to claim 1, characterized by the fact that each cam (17, 18) consists of a base (80) of rectangular shape fixed and accurately positioned in the bottom of the groove (1) of the plate cylinder (3) by means of screws (82) and at least one centering pin (81), and that above said base are two salient parts (84) of triangular shape and arranged such that the rollers (15, 16) can slide free from play between surfaces of these triangular salient parts which are orientated at 30 degrees with regard to the rotational axis (2) of the plate cylinder (3).
4. Device according to claim 1, characterized by the fact that the base plate (4) comprises, at adjacent the cams (17, 18), two rectangular openings (72) having larger dimensions than the bases (80), a plurality of openings (73, 76) adjacent each rectangular opening (72) adapted to rigidly and accurately fix therein two stirrups (74) which support the rollers (15, 16), other openings (63), spaced in the base plate (4) at regular intervals, accommodating said holding means (102) to secure the base plate (4) to the plate cylinder (3); said base plate (4) also supporting a front claw (5), the length of which is substantially equal to the length of the groove (1), and which is rigidly attached to the base plate by means of blocks (20) and supports (44); a rear claw (6) being arranged facing the front claw (5) and carried by fastening means (103) on a claw support (25) which is movable independently of the rear claw (6) solely in a parallel direction with the longest sides of the base plate (4).
5. Device according to claim 1, characterized by the fact that each holding means (102) consists of a bushing (64), having an outer diameter slightly smaller than the diameter of the opening (63) through which it extends, round which bushing are successively piled up a washer (67) resting on a bearing shell (65) resting on the base plate (4), a compression spring (66) and an upper washer (68) on which rests the head of a screw (69) that extends through the bushing (64) in order to screw into the bottom of the groove (1) of the plate cylinder (3).
6. Device according to claim 4, characterized by the fact that the stirrups (74) constitute bridges, in the largest surface of which are screwed from below the rollers (15, 16), these stirrups being arranged and fixed on the base plate (4) above each respective cam (17, 18).
7. Device according to claim 4, characterized by the fact that the claw support (25) consists of a metallic plate, the length of which being substantially equal to the length of the front claw (5), which is provided with a plurality of elongate apertures (26) spaced at regular intervals, orientated in a parallel direction with its longest sides, through which the fastening means (103) extend, each consisting of a stud (27) in which a screw (28) holding the rear claw (6) on the claw support (25) is screwed, the latter being mounted on at least two blocks (30) sliding each on an axis (31) orientated perpendicularly to the length of the base plate (4) and kept at its ends by two supports (32) screwed in the base plate (4), such that the rear claw (6) and the claw support (25) can slide along these axes (31) in a movement which effects closing and opening of the rear claw (6).
8. Device according to claim 7, characterized by the fact that the closing of the rear claw (6) is ensured by a plurality of compression springs (48) each resting on a retaining block (51) secured to the base plate (4) and pushing the rear claw (6) towards the front claw (5) by means of a plurality of plates (46) arranged at right angles to the front claw support (25) and secured to the lower surface of the latter.
9. Device according to claims 7 and 8, characterized by the fact that opening of the rear claw (6) is actuated by a plurality of pneumatic cylinders fixed on the supports (44) on an axis (47) which push back the plates (46) in order to compress the springs (48).
10. Device according to claim 8, characterized by the fact that each retaining block (51) is provided with a threaded hole for the passage of a compression spring (48), a plug (50) screwed in each hole serving as rest for said springs (48).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH01192/98A CH689717A5 (en) | 1998-06-02 | 1998-06-02 | Flexible printing plate positioner for rotary printing machine |
| CH19981192/98 | 1998-06-02 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2273388A1 CA2273388A1 (en) | 1999-12-02 |
| CA2273388C true CA2273388C (en) | 2003-07-01 |
Family
ID=4204660
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002273388A Expired - Fee Related CA2273388C (en) | 1998-06-02 | 1999-05-28 | Positioning device of a flexible printing plate on a plate cylinder |
Country Status (12)
| Country | Link |
|---|---|
| EP (1) | EP0972639B1 (en) |
| JP (1) | JP3192640B2 (en) |
| KR (1) | KR100334476B1 (en) |
| CN (1) | CN1085147C (en) |
| AT (1) | ATE236016T1 (en) |
| AU (1) | AU748606B2 (en) |
| BR (1) | BR9902635A (en) |
| CA (1) | CA2273388C (en) |
| CH (1) | CH689717A5 (en) |
| DE (1) | DE69906426T2 (en) |
| DK (1) | DK0972639T3 (en) |
| ES (1) | ES2195469T3 (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE0602709L (en) * | 2006-12-18 | 2007-10-09 | Berg Ind Ab | Device for clamping and tilting cliché mounting |
| BR112013008668B1 (en) | 2010-09-21 | 2020-12-01 | Bobst Mex Sa | process and adjustment of color registration for a printing machine |
| KR20130055172A (en) | 2011-11-18 | 2013-05-28 | 삼성디스플레이 주식회사 | Substrate aligning unit, substrate processing apparatus having the same and method of processing substrate using the same |
| US11485101B2 (en) | 2017-07-14 | 2022-11-01 | Georgia-Pacific Corrugated Llc | Controls for paper, sheet, and box manufacturing systems |
| US10642551B2 (en) | 2017-07-14 | 2020-05-05 | Georgia-Pacific Corrugated Llc | Engine for generating control plans for digital pre-print paper, sheet, and box manufacturing systems |
| US11520544B2 (en) | 2017-07-14 | 2022-12-06 | Georgia-Pacific Corrugated Llc | Waste determination for generating control plans for digital pre-print paper, sheet, and box manufacturing systems |
| US20190016551A1 (en) | 2017-07-14 | 2019-01-17 | Georgia-Pacific Corrugated, LLC | Reel editor for pre-print paper, sheet, and box manufacturing systems |
| US11449290B2 (en) | 2017-07-14 | 2022-09-20 | Georgia-Pacific Corrugated Llc | Control plan for paper, sheet, and box manufacturing systems |
| DE102018214610A1 (en) * | 2017-09-26 | 2019-03-28 | Heidelberger Druckmaschinen Ag | Cylinder with a clamping rail for holding a cylinder lift in a printing machine |
| CN112728603A (en) * | 2020-12-31 | 2021-04-30 | 成都温骅康裕商贸有限公司 | Energy-saving and environment-friendly device for cleaning filter plate of smoke exhaust ventilator |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1536954B2 (en) * | 1966-04-07 | 1971-08-12 | Adamovske strojirny, N P , Adamov (Tschechoslowakei) | DEVICE FOR SIMILAR SWIVEL ADJUSTMENT OF BOTH ENDS OF A FLEXIBLE PRESSURE PLATE |
| JPH07106629B2 (en) * | 1985-09-05 | 1995-11-15 | 大日本インキ化学工業株式会社 | Plate position correction device for printing machine |
| DE3604209A1 (en) * | 1986-02-11 | 1987-08-13 | Heidelberger Druckmasch Ag | DEVICE FOR CLAMPING FLEXIBLE PRINTING PLATES ON THE PLATE CYLINDER OF ROTARY PRINTING MACHINES |
| JP2926656B2 (en) * | 1989-09-13 | 1999-07-28 | アキヤマ印刷機製造 株式会社 | Plate twist adjustment mechanism for sheet-fed printing press |
| DE9318599U1 (en) * | 1993-12-04 | 1994-02-24 | Heidelberger Druckmaschinen Ag, 69115 Heidelberg | Device for pivoting flexible printing plates on the plate cylinder of rotary printing machines |
-
1998
- 1998-06-02 CH CH01192/98A patent/CH689717A5/en not_active IP Right Cessation
-
1999
- 1999-05-20 DK DK99109884T patent/DK0972639T3/en active
- 1999-05-20 AT AT99109884T patent/ATE236016T1/en not_active IP Right Cessation
- 1999-05-20 DE DE69906426T patent/DE69906426T2/en not_active Expired - Lifetime
- 1999-05-20 EP EP99109884A patent/EP0972639B1/en not_active Expired - Lifetime
- 1999-05-20 ES ES99109884T patent/ES2195469T3/en not_active Expired - Lifetime
- 1999-05-25 AU AU31253/99A patent/AU748606B2/en not_active Ceased
- 1999-05-28 CA CA002273388A patent/CA2273388C/en not_active Expired - Fee Related
- 1999-05-31 BR BR9902635-0A patent/BR9902635A/en not_active IP Right Cessation
- 1999-06-01 KR KR1019990020032A patent/KR100334476B1/en not_active IP Right Cessation
- 1999-06-02 CN CN99107831A patent/CN1085147C/en not_active Expired - Lifetime
- 1999-06-02 JP JP15531399A patent/JP3192640B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1085147C (en) | 2002-05-22 |
| ATE236016T1 (en) | 2003-04-15 |
| AU3125399A (en) | 1999-12-09 |
| CH689717A5 (en) | 1999-09-15 |
| JP2000033688A (en) | 2000-02-02 |
| DE69906426T2 (en) | 2004-02-12 |
| KR20000005811A (en) | 2000-01-25 |
| KR100334476B1 (en) | 2002-04-26 |
| EP0972639A1 (en) | 2000-01-19 |
| EP0972639B1 (en) | 2003-04-02 |
| CN1237513A (en) | 1999-12-08 |
| DE69906426D1 (en) | 2003-05-08 |
| BR9902635A (en) | 2000-02-22 |
| JP3192640B2 (en) | 2001-07-30 |
| CA2273388A1 (en) | 1999-12-02 |
| DK0972639T3 (en) | 2003-07-28 |
| ES2195469T3 (en) | 2003-12-01 |
| AU748606B2 (en) | 2002-06-06 |
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