FR2492734A1 - METHOD AND DEVICE FOR POSITIONING INK STATIONS OF A FLEXOGRAPHIC PRINTER - Google Patents

Abstract

THE INVENTION RELATES TO A PROCESS AND A DEVICE FOR POSITIONING THE PRINTING CYLINDERS AND WEFT-HOLDERS OF A FLEXOGRAPHIC PRINTER. THE DEVICE IS CHARACTERIZED IN THAT IT INCLUDES, IN COMBINATION, A DIGITAL ELECTRONIC ASSEMBLY 41 TO 58 FOR AUTOMATIC TAKING INTO ACCOUNT BY DISPLAYS 42, 47 TO 50 OF THE PRECISE VALUES OF THE VARIABLE PARAMETERS WITH A VIEW TO PRECISE POSITIONING OF AT LEAST ONE INKING STATION COOPERATING WITH AN ELECTRONIC ASSEMBLY 59, 60 FOR STORING CORRECTION ADJUSTMENTS AND VARIABLE PARAMETER DISPLAY FOR A LATER POSITIONING OF THE INCHING STATION (s) IDENTICAL TO THE PREVIOUS POSITIONING DURING A EXTERNAL RESUMPTION OF THE SAME PRINTING JOB WITH THE SAME PRINTING CYLINDERS. THE INVENTION RELATES TO PRINTING.

Description

- 2492734

  The invention relates, on the one hand, to a method and, on the other hand, to a device for the precise positioning of the station or stations

  inking, in particular printing cylinders such as cylinder cylinders

  dies and rolls of a flexographic printer, independent positioning of the thickness tolerances of the plates and their

  Adhesive ports, thicknesses of printing materials and

  caniques of transmission of the positioning means.

  A flexographic printer has a general frame on which are disposed one or more printing stations called stations

  inking. The strip of material to be printed passes successively through

  to the various inking stations to make the impression of a

  pattern in one or more shades. For independent technical reasons

  of the subject of the present invention, the flexographic printing machines

  may be - either of the type with individual counterpressure, including, for each printing inking, a drum called a counterpressure cylinder and

  serving as support for the strip of material to be printed.

  either of the single-counterpressure type comprising a central drum serving as a support for the band of material to be printed and around which

  the various inking stations are arranged.

  Each inking station comprises, on either side of the longitudinal axis of the printer, a frame provided with a rectilinear slide on which moves a slide provided with a bearing in which

  is housed the lateral rocket of the cliché cylinder arranged transversally-

  with respect to said longitudinal axis. On this slider linearly moves a support comprising, on the one hand, the bearings of the halftone cylinder carrying the printing ink on the mounted flexible plates.

  on the cylinder and, on the other hand, the bearings of a cylinder bar-

  a botter taking the ink in a cross-sectional container and dosing it, by applying

  cation on the screen cylinder, the ink film for printing.

  During the printing operation, the different cylinders are positioned relative to each other to allow the transfer of the ink taken from the tray by the cylinder bubbler to the cylinder

  from the latter to the cliché of the cliché cylinder and, finally, from the

  to the web of print material supported by the drum

  central, or by the counterpressure cylinder.

  If the printing process stops, the cylinder

  must be cleared both in relation to the cylinder and

  2-drepressure supporting the strip of material to be printed than with respect to the screened cylinder ensuring the transfer of the ink. Various known technical solutions make it possible to print and / or print one or more or all of the flexographic inking stations. On modern printing machines, setting operations and / or

  out of print of each inking station are carried out by means of

  linear and limited placements, on the one hand, the slider provided with the cylinder shot on the slide of the frame and, secondly, the support provided with the screened cylinders and bubbler on the slider. Similarly, during the assembly and / or disassembly of the cylinders cliches, the release of the slides and supports relative to the slide of the general building

  are made by linear movements of the different parts between them.

  For this purpose, adjustment and positioning screws actuated by

  "step-by-step" control means make it possible to move

  port to the slide of the general building. These control means "step by step" comprise, in general, a reference point corresponding to the position of the maximum clearance of the slider and the support. This point of

  reference is taken into account by the control means for the posi-

  between the cylinders according to the development of the cy-

lick cliché.

  When mounting a cliché cylinder, the slide and the

  port are in a position of maximum clearance. This posi-

  tion constitutes a reference position by a digital control means of the motors "step by step" actuating the adjusting screws. After assembly of the forme cylinder, a display system makes it possible to introduce a theoretical setpoint display corresponding to the development of the forme cylinder mounted in the sliders for a printing operation. The setpoint is converted into a number of pulses necessary for the energy supply of the "step-by-step" motors actuating the adjusting screws, in particular when releasing the positioning command of the sliders, supports and their cylinders. The motors receive a given number of pulses to ensure exact theoretical positioning from the position

  reference. The setting in and out of the cylinders of the sta-

  Inking operations are carried out according to a number of steps of the predetermined and invariable adjustment screw irrespective of the development of the forme cylinder, the number of steps determining the stroke length 3-

  engaging or disengaging the slide and support.

  During printing, the precise positioning settings, ne-

  necessary for a perfect impression, are obtained by means of

  Isolated engagement and / or release lugs on any of the adjusting screws. This known technical solution, although being precise in the positioning, has some disadvantages in practice. In

  indeed, it does not take into account, during the processing, a certain

  number of variable parameters and, in particular, the value of

  development in "no" position of the motors, the thick-

  of the material to be printed, thickness tolerances of the

  mounted with their adhesive support on the cylinder body, tolerances on the theoretical diameter of the screen cylinder and games

  mechanical transmissions of the positioning means.

  The different parameters force the printer's driver to make multiple and important positioning corrections

  clichés cylinders and screened by acting by means of iso-

  engagement and / or clearance on any of the engines

  "step by step" adjustment to ensure exact positioning of

  cylinders for perfect printing.

  The object of the present invention is to remedy these drawbacks and proposes to provide a method and a device improving the operation of a flexographic printer by limiting for each inking station the positioning correction operations of the printing machines.

  clichés and halftone cylinders. Moreover, the present invention

  means for the exact positioning of said cylinders in the event of one or more repetitive jobs without further correction when the same print job is subsequently resumed with the same

same impression cylinders.

  For this purpose, the invention relates to a method for positioning

  the inking station (s), in particular cylinders

  such as image cylinders and screened cylinders of an im-

  flexographic primeuse, independent positioning of the thickness tolerances of the plates and their adhesive supports, the thicknesses of the materials to be printed and the mechanical games for the transmission of the positioning means, characterized in that the values are automatically taken into account precise variable parameters,

  in particular thickness parameters of the material to be printed, tolerance

- -

  these thicknesses of the clichés and their adhesive and dia-

  meter cylinder as well as mechanical games in the transmitters

  setting screws, and that it is possible to store all the correction settings and the variable parameter display for subsequent positioning of the inking station (s) identical to the previous positioning during a subsequent restart. of the same

  print job with the same print cylinders.

  The invention also relates to a device for positioning

  the inking station (s) according to the above procedure,

  characterized in that it comprises, in combination, an electronic assembly

  digital automatic recognition by displaying precise values of variable parameters for accurate positioning

  at least one inking station cooperating with an electronic unit

  than setting the settings for correcting and displaying

  variable parameters for later positioning of the sta-

  Inking operations identical to the previous positioning when the same print job is subsequently used with the same cylinders

- printing.

  Therefore, when resuming a job whose settings have

  memorized, the call of the corresponding memory and its transmission

  mission to the control means of motors "ipas a pas" de positionne-

  allows instant recovery and without additional correction

print jobs.

  The invention will be well understood with reference to the description

  following example by way of non-limiting example and the accompanying drawing in which

  FIG. 1 is a schematic view in elevation of a station of

  flexographic core in its printing position

  FIG. 2 is a schematic view in elevation of this same sta-

  flexographic inking unit in its position of disengaging the cylinders.

dres

  FIG. 3 is a diagram of the electronic assembly for taking into account

  automatically by displaying the precise values of the various parameters

  and storage for an inking station - Figure 4 is a diagram of the electronic assembly for taking into account the actual mechanical transmission of each set of screws and positioning motors for a station. inking - Figure 5 is a diagram of the electronic assembly applied to a

  printer with several ink stations.

Referring to Figures 1 and 2.

  The flexographic printer has a counterpressure cylinder

  1 serving as support for the material to be printed.

  pressure 1 is placed between two frames 3, 4 arranged on both sides

  longitudinal axis of the printer and, for a better understanding of

  description, these frames 3, 4 will be referred to as right frame 3,

  left frame 4 seen in the unwinding direction of the material to be printed 2.

  Each frame 3, 4 comprises a slide 5, 6 on which

  places an inking station 7 having a right slider 8 and a left slider 9. These sliders 8, 9 comprise a bearing 10 in which is housed the side flare of a plate cylinder 11 provided with one or more plates 12. This cliché cylinder It is therefore interspersed

between the slides 8, 9.

  The displacement of the slides 8, 9 is ensured by an element Mo-

  positioner 13 and by a positioning motor element

  14. These motor elements 13, 14, advantageously constituted by stepped lipas motors, actuate right and left adjusting screws 16. These adjusting screws 15, 16 passing through a stop 17, 18,

  have, at their free end 19, 20, a stop 21, 22.

  The top 23 of the sliders 8, 9 serves as a slider for a straight support 24 and left 25 moving linearly. The supports 24, 25

  comprise bearings 26 for the lateral flares of a working cylinder.

  27 and bearings 28 for the lateral flares of a barb cylinder.

  29. The bubbler 29 draws the ink in a cross-flow container.

  Sal 30 and dose per application on the screen cylinder 27 the printing ink film.

  The displacement of the supports 24, 25 is ensured by a modular element

  positioner 31 and by a positioning motor element

  32, also constituted by "step-by-step" motors and ac-

  33 and left right adjustment screws 34, the free end

  35, 36 passes through a guide 37, 38. The supports 24, 25 cooperate

  with a stop 39, 40 secured to the top 23 of the slides 8, 9.

  For disengagement, the driving elements 13, 14 are actuated

  trailing the adjusting screws 15, 16 and the slides 8, 9 retreating until the stops 21, 22 come into contact with the stops 17, 18. As a result, the cylinder cliche It is cleared and is no longer in contact with the material to be printed 2. Then, the motor elements 31, 32 acting on the adjusting screws 33, 34 are actuated so that the

  supports 24, 25 recede until they abut against the arms

  39, 40. Thus, the screen cylinder 27 is cleared and is no longer

  contact with the plate cylinder II (see figure 2). It is then possible

  to mount and / or dismantle the latter corresponding to a certain development. For commitment, we proceed in the opposite way. However, the positioning of the forme cylinder and the screen cylinder 27 must be

very precise.

Referring to Figure 3

  The different motor elements 13, 14 and 31, 32 are controlled

  through a digital control unit 41 which solicits

  motors 13, 14 and 31, 32 according to the known principle of "not". Cha-

  that "not" motors 13, 14 and 31, 32 corresponds to a specific rotation

  of the adjusting screws 15, 16 and 33, 34 thus to precise displacement and positioning of the slides 8, 9 and supports 24, 25 by

  relative to the frames 3, 4, therefore compared to the stops 19, 20 and 39, 40.

  During an assembly and / or disassembly of a cylinder cliché It

  provided with his printing plates 12, a display of

  mat 42. This 42 format display is decoded and transcoded in the breeder.

  41. During the command for the establishment of the sliders 8, 9 with the plate cylinder 11 and supports 24, 25 with the screen cylinder 27, the digital control unit 41 sends

  the impulses of "not" to the motor elements 13, 14 and 31, 32 by the

  via its own digital control systems 43, 44 and 45, 46

  each positioning motor element 13, 14 and 31, 32.

  are counted in a counter inherent in the digital control unit 41 and the digital control units 43 to 46 up to the number of decoded and transcoded pulses from

  42. The slides 8, 9 and the supports 24, 25 are posi-

  and, after printing, the final position of the slides

  buckets 8, 9 and supports 24, 25 corresponds to the theoretical position of the inking station 7 in which the correct printing of the material

  to print 2 can be done (see Figure 1).

  However, various external parameters may influence this theoretical position and in particular: the thickness tolerances of the plates 12 arranged on the forme cylinder 11, the thickness tolerances of the material to be printed 2, the tolerances of the outside diameter of the screened cylinder 27, - tolerances or clearances in the mechanical transmission assemblies consisting of screws 15, 16, 33, 34, stops 21, 22 and stops 17, 18, 39, 40 arranged between the driving elements 13, 14, 31, 32 and the slides

buckets 8, 9 and supports 24, 25.

  To overcome these variable parameters, the digital set of

  digital control 41 is complemented by digital display

correction items 47, 48, 49, 50.

  The digital display assemblies 47, 48, 49, 50 make it possible to introduce directly, when mounting a plate cylinder 11 with the plates 12, the correction, positioning parameters of the sliders 8, 9 and the supports 24, 25 to correct the theoretical positioning of the slides 8, 9 and supports 24, 25 and, consequently, to correct algebraically the number of theoretical "steps" predetermined by the format display 42 and to be retransmitted via digital control sets 43 to 46 to the elements

motors 13, 14 and 31, 32.

  Of course. these parameter corrections can be subtracted

  or additive according to the algebraic value of the tolerances

to theoretical values.

  The digital correction display 47 relates to taking into account

  by the digital control unit 41 acting on the motor elements 13, 14 and 31, 32, mechanical clearances or tolerances in the motion transmissions between the motor elements 13, 14 and 31, 32 and the sliders 8, 9 and supports 24, 25. Indeed, any mechanical transmission system is subject to a certain clearance. Thus, between a movement of advance and retreat slides 8, 9 and / or supports 24, 25 required during corrections end of the adjustment settings of each adjusting screw 15, 16 and 33, 34, it is appropriate

  to catch up with the mechanical play in the system of transformation of the

  motor elements 13, 14, 31, 32 in linear motion of

  slides 8j 9 and / or supports 24, 25. For each station of

  7 and for the mechanical transmission movement of each motor element 13, 14, 31, 32, the clearance can be meticulously measured and the values of these games can be introduced by means of the display.

  numerical correction 47 and be taken into account by the nu-

  control system 41 and this at each inversion of the direction of de-

- 8 -

  placement of slides 8, 9 and supports 24, 25 and all

  during precise positioning operations during printing. It is the same during the engagement and disengagement operations of the sliders 8, 9 and supports 24, 25 at the time of printing on or off the inking station 7. The digital correction display 48 regards tolerances

  algebraic thicknesses of the plates 12 compared to the thickness no-

  theoretical and theoretical clichés with their adhesive media while

  the digital correction display 49 relates to the display of the thick-

  2. In addition, the correction digital display 50 relates to the algebraic tolerances of the dimensions of the

  screen cylinder 27 with respect to the nominal nominal diameter.

  After printing a flexographic inking station

  7, the driver of a printer is obliged, despite the various

  corrections mentioned above, to make certain adjustments to the

  positions on one or other of the adjusting screw assemblies 15,

  16,33,34 - positioning motor elements 13,14, 31,32 of which is

  7. For this purpose, it is expected that in an im-

  pressure, the operator can intervene independently on any one of the four motor elements 13,14,31,32 via donors

  advance pulse 51, 52, 53, 54 and / or recoil 55, 56, 57, 58

matted in Figure 3.

  The digital control assemblies 43 to 46 of the motor elements

  13, 14, 31, 32 take into account manual corrections or pulses.

  delivered by the operator and allow the final positioning of the

  slides 8, 9 and supports 24, 25.

  The number of manual corrections performed by the operator on each motor element 13, 14, 31, 32 is stored either by the digital control assemblies 43 to 46, or by the digital control unit 41. Therefore, it is possible to know the precise positions of the sliders 8, 9 and the supports 24, 25, in particular the exact number of "steps" via the stops 21, 22 and 39, 40 for each of the driving elements 13, 14, 31 , 32 arranged on an inking station 7. In case of a repetitive work, it is possible to memorize, from the

  printing position of an inking station 7 characterized by a name

  number of "steps" for each motor element 13, 14, 31, 32 from the

  reference numbers 21, 22 and 39, 40 the different positions in the

  appears to be digital control 41 and in digital control assemblies

  rate 43 to 46 by using the request for information and its storage in a means 59 comprising a set of call and setting

  memory shown schematically in Figure 3 by a pushbutton 60.

  The possible need to keep in memory the positions of several repetitive works is feasible by the addition of

  several systems equivalent to the means 59 and the pushbutton 60.

  When resuming a print job stored in the first embodiment and considering that the ink station 7 is in the mounting position or disassembly of the forme cylinders Il as shown in Figure 2, it it is possible to directly input the positioning values previously stored and, without using the various correction displays 42, 47 to 50, to put the ink station 7 in the exact position without being obliged, when printing, to make additional manual corrections through impulse donors in advance

51 to 54 or back 55 to 58.

Referring to Figure 4

  The display 47 of the mechanical transmission sets relates to the four sets of positioning: adjusting screws 15, 16, 33, 34 and

  motor elements 13, 14, 31, 32 constituting the inking station 7.

  For this reason, the display 47 can be subdivided into four af-

  471 472 '4739 474 to allow the actual play of each positioning set to be taken into account. In this case, the displays

  471 472 '473' 474 are applied directly to the control sets

  of numerals 43-46 of each positioning motor element 13, 14,

31, 32 of an inking station 7.

  Similarly, it is conceivable that the correction displays 48 and are also done individually for each inking station

  7. The correction display 48 applies to the positioning of the

  slats 8, 9 and supports 24, 25. The display 50 only relates to

  the supports 24, 25, therefore consequently, that the screws 33, 34.

  It goes without saying that the same principle applies to a printer

  flexographic system comprising a plurality of inking stations 71 '72' 739 74 '75' 76. FIG. 5 schematizes the principle of FIG.

  a flexographic printer with several printing stations

  ge 71, 72 '73 .... The same digital control unit 41 serves for the establishment of information and their transmission to four -] 0 -

  motor elements 13, 14, 31, 32 of each inking station 71 7273 ....

  A commissioning assembly 611, 612, 613, 614, 615, 616 serving to select the inking station (s) 71, 72 73 74 75 76 must take into account the information supplied by the digital control unit. for the positioning of inking stations 71 '72'

  73 ... having to do some printing work.

  The arrangements shown in Figures 3 to 5 are not

  only as an example. In fact, depending on the use of a printer

  flexographic, the displays of the various corrections can be

  individual stations for each inking station.

  decoded and transcoded data from the digital posters of

  Rections 47, 48, 49, 50 can be taken into account directly by the digital control assemblies 43, 44, 45, 46 of each positioning motor element 13, 14, 31, 32. The introduction of the display (42 ) the development of the forme cylinders 11 as well as the display (49) of the thickness of the material to be printed 2 can remain general for all the inking stations 71, 72 '73, 74, 75, 76 of a

  printer and applied to the central unit.

  According to a first embodiment, the advance pulse donors 51, 52, 53, 54 or recoil 55, 56, 57, 58 are arranged near

  inking stations 71, 72, 73 '74 75 76 ....

  According to one embodiment, the additional impulse donors

  51, 52, 53, 54, 55, 56, 57, 58 for each inking station 71, 72 '73, 74, 75, 76 are arranged in other places of the flexographic printer and more particularly near an observation post

  and viewing the material to be printed 2.

  Although the invention has been described in connection with a form of

  particular, it is understood that it is by no means limited and that various modifications of

  materials and combinations of these various elements without

  away from the frame and spirit of the invention.

_ He I-

Claims (10)

claims   1. Method for precise positioning of the station (s)   inking, in particular printing cylinders such as cylinder cylinders   halves and rolls of a flexographic printer, position-   independent of the thickness tolerances of the plates and their adhesive supports, the thicknesses of the materials to be printed and the mechanical games for transmitting the positioning means, characterized in that   what is automatically taken into account by displaying (47 to 50) the values   their precise variable parameters, including parameters of   thickness of the material to be printed (2), tolerance of the thicknesses of the plates (12) and of their adhesive supports and the diameter of the screen roll (27) as well as mechanical clearances in the transmission of the screws   setting (15, 16, 33, 34) then it is possible to store   re all the correction settings and the display (47 to 50) of   very variable for a subsequent positioning of the inking station (s) (71, 72 '73 ...) identical to the previous positioning when a subsequent printing of the same print job with the same   printing cylinders (11) and (27).   2. Device for the precise positioning of the inking station (s) according to the method according to claim 1, characterized in that it comprises, in combination, a digital electronic assembly (41 to 58) for automatic taking into account by displays (42), (47 to 50)   precise values of the variable parameters with a view to   precise location of at least one inking station cooperating with a set   electronic memory (59,60) for storing the correction and variable parameter display settings for later positioning of the inking station (s) identical to the previous positioning when an external recovery of the same work is performed impression with the same impression cylinders.   3. Device according to claim 2, characterized in that it comprises, for each positioning motor element (13, 14, 31, 32) of each inking station (7), a digital control assembly (43, 44 , 45,46) provided with an advance pulse donor (51,52,53,54) and a reverse pulse donor (55, 56, 57, 58), the sets (43, 44) and (45, 46) being connected in pairs to a digital set of control (41). - 12 -   4. Device according to claim 2 characterized in that it comprises a set of digital correction correction display (47)   automatic account, by the digital control unit (41) acts   on the positioning motor elements (13, 14, 31, 32), mechanical clearances or tolerances in the motion transmission between the driving elements (13, 14, 31, 32) and sliders (8, 9) provided   a forme cylinder (11) and supports (24, 25) provided with a cylinder dre halftone (27).   5. Device according to claim 2, characterized in that it comprises a digital correction display (48) for taking   automatic counting by the digital control unit (41) of the   algebraic ries of the thicknesses of the clichés (12) compared to the nominal and theoretical thickness.   6. Device according to claim 2, characterized in that it comprises a digital correction display (49) for taking   automatic counting by the digital control unit (41) of the thick of the material to be printed (2).   7. Device according to claim 2, characterized in that it comprises a digital correction display (50) for taking into account.   automatic counting by the digital control unit (41) of the   algebraic rances of the dimensions of the screen cylinder (27) with respect to nominal nominal diameter.   8. Device according to claim 2, characterized in that it comprises a storage means (59) provided with a call and storage assembly such as a push button (60) connected to the 'together digital control (41).   9. Device according to claim 2, characterized in that it comprises a set of commissioning (61) serving as a selection of   the inking station or stations (71, 72 '73) of a flexographic printer   than at several inking stations (71, 72 '73, 74 ...).   Device according to claim 3, characterized in that the advance pulse donors (5I, 52, 53, 54) and the reversing pulse donors (55, 56, 57, 58) are arranged in close proximity. a   observation and viewing station for the material to be printed (2).