FR2635717A1 - BATI OF A FLEXOGRAPHIC PRINTING MACHINE - Google Patents

Abstract

The invention relates to a frame of a flexographic printing machine with an individual backpressure cylinder and comprising one or more printing units. The frame of this flexographic printing machine is characterized by the fact that it is modular, with each module 16 to 19, 69 and 70 corresponding to a printing unit and its associated backpressure cylinder. The invention will find its application both among manufacturers and users of printing devices and, in particular, of machines of the flexographic type.

Description

The invention relates to a building of an ilexographic printing machine with

  individual counterpressure cylinder and

  with one or more printing groups.

  The invention will find application both among manufacturers and users of printing devices

  and, not surprisingly, machines of the flexographic type.

  The process of printing is particularly well known and consists in printing on web media such as paper, cellulosic film, aluminum, plastics, etc. These impressions are made, more precisely, by passing the strip between a counterpressure cylinder and a forme cylinder, the latter postponing the graphics to be printed on the support. An ink cylinder receives a dosage of ink from either a bubbler cylinder bathed in a basin containing ink, or by any other device, and ensures the transfer of ink to the platen cylinder. The combination of these different

  cylinders constitutes a printing group.

  The number of these printing units, grouped in a flexographic printing machine, will depend on the number of basic shades constituting the printing. There are so-called two-color, four-color or six-color machines. When printing requires a higher number of shades, it is common to associate multiple units or

  flexographic printing machines.

  Among the latter, there are also those which are said to single counterpressure cylinder around which are arranged the various inking stations and those

  say to individual counterpressure cylinder.

  The present invention relates more particularly to flexograph printing machines of the second type and comprising, for each printing unit a counterpressure cylinder. Thus, the current design of these flexographic machines with individual compression cylinders consits into a frame formed by two parallel parols disposed on either side of a vertical plane passing through the iongludimentary axis of the strip forming the medium to be printed. These walls are held together by means of crossbeads distributed over the entire height of the bati. Moreover, their size and their design are function or number of groups where printing. Alnesi, this number is determined in a definitive way at the time of the design of the machine

flexographic printing.

  On this frame are fixed, horizontally, the different counterpressure cylinders and implanted the drive mechanisms of the latter. In addition, the front and rear walls forming said frame are provided with bearings for accommodating a whole series of tape return rollers to guide the latter through the machine.

during printing.

  The locations for the printing units are debsinrésr on the frame to the right of each counterpressure cylinder. such locations may consist of slides arranged on each of the front and rear walls, slides on which is mounted, sliding, a carrier which is associated with the forme cylinder. The inking device composed of the ink cylinder and the bubbler cylinder is, according to this particular embodiment of embodiment, secured to a second support itself freely mounted in translation on the

support of the forme cylinder.

  Of course, the shape of these locations will depend on the particular design of the printing units and the aforementioned slides may be substituted for means

different media.

  The disadvantages of these flexographic printing machines consist, in essence, of their rigid design, the origin of their application reduced to conditions

print data.

263 5 7 1 7

  By way of example, a four-color machine consists of four printing units, it allows, alsos, the printing in four different colors or printing.

  a double-sided tape requiring four applications.

  b Performed by such a machine, a two-color printing or falsely intervene that two printing groups consists of reducing, by half, the profitability of this machine. This translates, undeniably, into a higher manufacturing cost. Indeed, whatever the type of printing chosen, the cost of use is identical and it is preferable to use the printing machine

  Llexographic in all its capacity.

  Taking into account only this reasoning, a printing unit would be equipped with means of production far superior to its workload or would have such a rigidity, as to the diversity of the products designed, that it could not be used. systematically adapt to market demand. It is therefore necessary to find an economic compromise which only rarely corresponds to the cost of

minimum production.

  Moreover, from the point of view of the manufacturer, this diversity existing in the optical printing machines, does not allow them, unless they have a large and expensive stock, to satisfy the immediate demand. Indeed, a six-color flexographic printing machine can not be suitable for a buyer of a flexographic printing machine which is limited to two or four printing groups. The present invention aims to remedy all of the aforementioned drawbacks by proposing a flexographic printing machine of modular character allowing the removal or addition of printing units according to the

  nature of the printing & making or the customer's request.

  This module design of the bati of an machinelexographic machine gives the latter a high degree of adaptability to a variety of manufacturing programs.

  and, at the cost of production always optimized.

  To this end, the invention relates to a batl of a flexo printing machine with individual counterpressure cylinder and comprising one or more printing units, characterized in that it is flexible, each module corresponding to a group of impression and its cylinder

associated compression.

  Other aims and advantages of this proposal

  in the course of the description which follows and which

  However, it is given only as an indication and not as a limitation.

  The understanding of this description will be facilitated by

  Referring to the accompanying drawings in which: - Figure 1 shows, schematically and in elevation, a flexographic printing machine according to the invention

  and having four printing groups.

  FIG. 2 is a view identical to FIG. 1, the lithographic printing machine being provided in this case with six printing units; FIG. 3 represents a detailed view of one embodiment of the means for positioning one module of the frame relative to another; FIG. 4 is an enlarged view of the portion marked A in FIGS. 1 and 2 and showing the connection between two modules;

  composing the frame of the flexographic printing machine.

  It should be noted that the same reference in the various figures designates the same constituent element of the

  flexographic printing machine.

  Referring to FIG. 11, the present invention relates more particularly to frame 1 of a flexographic printing machine 2 of the individual counterpressure cylinder type. Thus, these printing machines comprise for each printing group 3,4,5,6 (four in number in FIG.

counterpressure 9,10,11,12.

  The number of these printing units is, of course, depending on the number of printing layers to be transferred to the substrate 15, which is constituted by a web, for example a web, a cellulosic film, aluminum or plastics. So can we design printing machines

  Ixxographic to two, six or more printing groups.

  Any flexographic printing machine consists of a frame 1 serving as a support for the different printing groups 3 to 6 and on which the counterpressure rollers 9 to 12 are fixed. This frame 1 also contains motor and compression means. drive (not shown) capable of animating said counterpressure cylinders 9 to

  12 of a rotating movement during production.

  However, the frame according to the invention has the particularity of being flexible. Each pair printing group 3 to 6 and counterpressure cylinders 9 to 12 corresponds to a basic module 16,17,18,19 said because of their identity regardless of their position in the machine

flexographic printing.

  More precisely, a base module 16 to 19 consists of two walls 20 arranged in parallel and symmetrically with

  on both sides of the longitudinal median plane of band 15.

  These walls 20 are made integral with each other by means of sleepers 21,22,23 whose number and section can be

  determined according to material resistance criteria.

  It has therefore been recommended, according to the embodiment represented in FIGS. 1 and 2, to use a section 21 of considerable mechanical strength (for example, with a "U" or "I" section) to connect the walls 20 at what constitutes, as described below, the location of a printing unit. This gives a better transverse stiffness. The addition of two additional crosspieces 22, 23 arranged at different heights, consolidates the assembly. The sleepers 22,23 being located on the side of the passage of the band, they will be chosen preferentially, of round section so as not to deteriorate said band 15 during its

  threading in the flexographic printing machine 2.

  Of course, other embodiments may be envisaged for connecting the walls 20 of a module 16 to 19. These walls 20 furthermore comprise a bearing 24 in which is mounted, free in rotation, one of the ends 9 to 12. Other bearings may be housed or provided in these walls 20, a module 16 to 19, such bearings for holding tape return rollers 25,26, orienting the latter to through said module 16 to 19. Also mounted on these walls 20 a pressure cylinder 27 pressed against the counterpressure cylinder 9 to 12 by pneumatic cylinders to ensure the entrainment of the support to be printed on the first group

printing 3.

  In fact, it should be remembered that a printing unit 3 to 6 is composed, in all cases, of a forme cylinder 28 to 31 on which are reported the photographs that are to be taken. These plate cylinders 28 & 31 are of variable diameter, depending on the printing format, and are arranged, parallel to the counterpressure cylinder 9 to 12, so as to cooperate with the latter during printing. . They are, moreover, mounted free to rotate on a support 32

  mobile in translation on the Bati 1.

  In addition, these printing units 3 & 6 comprise an ink roll 33, 34,35,36 generally screened, ensuring the transfer of ink, in a predetermined dosage on the forme cylinder 28 & 31. This ink cylinder 33 at 36 is secured to a slider 37 capable of moving on the plate support 32 in a direction parallel to the displacement

of the latter on the b & ti 1.

  Since each module 16 to 19 of the frame 1 is associated with a printing unit 3 to 6, their walls 20

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  comprise support means 38 of the latter. The design of these support means 38 will be more particularly adapted to that of the supports 32 of the forme cylinders 28 to 31. By way of example, mention may be made of the rails formed by a straight flat surface and scraped

  on which the above-mentioned supports 32 may evolve.

  The various modules 16 to 19 being brought and superposed on each other, they advantageously comprise, according to another characteristic of the invention, on the one hand, means 39 ensuring their positioning relative to one another and means of

  link 40 to make them integral.

  According to a preferred embodiment, the positioning means 39 consist of a key 41 which is housed in a groove 42 machined on the upper edge 43 of the walls 20 of a module 16. This key 41 cooperates with a groove 44 arranged in the lower edge 45 of the walls 20

  a module 17 coming to position immediately above.

  Thus, each wall 20 of a module 16 to 19 comprises, on its upper edge 43 and inside 45, a groove

  dimensions adjusted to those of the clavette 41.

  This provision is particularly visible in

Figures 1 and 3.

  In order to facilitate assembly and avoid a shift of the key 41 during assembly, the latter is fixed, beforehand, and by means of fasteners 46.

  such as a screw on the walls 20 of a module 17 & assemble.

  According to the embodiment shown, said key 41 is positioned on the walls 20 in a direction perpendicular to the plane of the latter. It can not, therefore, guarantee their positioning in a direction transverse to the longitudinal median plane of the support 15. To this end, have been arranged, at both ends 47,48 of said key 41, tapped orifices 49,50 in which are screwed bolts 51,52 provided with a washer 53,54 bearing, respectively, on the inner face 55 and outer 56 of the walls 20, both the upper module 17 and lower 16. The tightening of these bolts 51, 52 causes, under the impulse of the washers 53,54 the alignment of walls 20 superimposed modules 16,17 concerned. As for the connecting means 40, they can be designed by any removable fastener such as screws 57 inserted in orifices 58 factories in the lower edge b9 60,61 openings formed in the inner portion 62 of the modules 17 Such screws 57 cooperate with tapped orifices 63 present in the upper edge 43 of the walls 20.

has an associated module 16.

  For threading considerations of the paper web or the like in the machine for double-sided printing, it is customary to design the frame 1 of said machine 2 symmetrically with respect to a transverse median plane 64

  & the longitudinal axis of said strip 15.

  Thus, in order to facilitate the combination of modules 16, 17 arranged on one side of said transverse median plane 64, with those 18, 19 located on the opposite side, the frame 1, according to the invention, comprises a on the other hand, a base 65 on which the lower modules 16, 18 are fixed. This base 65 rests on the ground and may be part of, in some cases, a structure 66 external to the flexographic printing machine

  and ensuring the orientation of the support 15 in the latter.

  On the other hand, the frame 1 comprises a cap 67 which, just as the base 65 can be integrated & the external structure 66

  and ensures the connection of the higher 17,19 modules.

  The positioning means 39 and the connecting means 40 involved in the cooperation of a lower module 16,18 with the base 65 or an upper module 17,19 with the

  hat 67 may be identical to those mentioned above.

  In this connection, it will be noted that the embodiment of these positioning means 39 and of these connection means 40 described above is in no way limiting, other modes

Execution is feasible.

  By way of example, as positioning means 39, mention may be made of the nipples which, arranged on the upper edge 43 of the walls 20 of a module 16 A 19 and cooperating with a bore bent in the lower edge 45 of said walls 20 a module 16 to 19 superimposed ensure a perfect tracking

of these modules 16 & 19 between them.

  Figure 2 shows a flexographic printing machine b8 provided with a frame 1 provided with six modules 16 Ai9, 69 and 70. This type of design requires the consideration of special conditions of flexographic printing. Indeed, it is important to ensure a good impression that the contact of the support 15 with a cylinder

  plate holder 28 & 31 is limited to a generator.

  However, by conferring on this support a trajectory corresponding to the tangent to these forme cylinders 28 to 31, the contact is made on a sector and not on a generator because of the pressure exerted on the cylinder

counterpressure 9 to 12.

  Therefore, it is necessary to ensure a winding part] of the strip 15 around each of said counterpressure cylinders 9 to 12. It is not necessary to obtain this partial winding by the addition of an intermediate roller return cooperating with the face of the band 15 freshly printed. As part of a unit of two or four printing groups, the solution la. simpler is to print at the path of the strip 15, at the input and output of a superposition of modules -16,17 or 18,19, a certain angle with respect to the vertical so as to obtain The solution to the problem posed in the case of a six-color machine 68 consists, advantageously, in providing the moduies 16 to 19, 69 and 70 with means 71. allowing them to be shifted together in a horizontal direction and while maintaining the positioning means 39 and linkage 40 adopted for the designs at two or four inking stations. These means 71 consist, on the one hand, in a particular arrangement of the grooves 42 and 44 machined in the upper edge 43, respectively, and the lower edge 45 of the walls 20 of each of these modules 16 to 19, 69 and 70. More specifically these grooves 42,44 sonL made at a reduced distance from the inner side edge 72 of said walls distance substantially corresponding to the offset conferred to the various modules. More exactly, in order to solve the problem of winding the web around the counterpressure roll 9 & 14, while keeping the arrangement defined in the four-color process, it is necessary to move the modules further away. intermediates of the transverse median plane 64 with respect to the other modules 16, 69, and

18.70.

  Due to the proximity of the grooves 42,44 of the rear lateral edge 72 of the walls 20, the intermediate module 17,19 is positioned relative to the lower module 16,18 and 69,70 higher by cooperation of said rear lateral edge 72 of this intermediate module 17,19 with the keys 41, fixed respectively in the groove 42 in the upper edge 43 of the walls 20 of the lower module 16,18 and in the groove 44 machined in the lower edge 45 of the

  walls 20 of the upper module 69,70.

  It is in these conditions that the option of fixing the keys 41 on their respective module by means of

  fixation 46 really finds its interest ..

  Another more expensive solution consists in multiplying the number of grooves 42, 44 in the various walls 20,

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  the difference of these grooves 42,44 corresponding, sernsablement, to

  the amplitude of the offsets printed on the modules.

  The means 71 are supplemented by the creation of additional orifices 76 in the lower edge 59 of the openings 60, 61 made in the lower part 62 of the walls 20. These orifices 75, 76 serve for the passage of screws 57 and respect a gap by relative to the central orifice 58 corresponding to the aforementioned offset so that said screw 57 is able to cooperate with the same threaded orifice 63 present in the upper edge 43 of the walls 20 whatever

  the position of the modules 16, 17, 69 or 18, 19, 70 between them.

  The advantages obtained by means of this invention consist, mainly, in a standardization of the material

  ilexographic printing thanks to a modular design.

  Although the invention has been described with respect to a particular embodiment, it is understood that it is in no way limited and that various modifications of shapes, materials and combinations thereof can be made. various elements without departing from the frame and

the spirit of the invention.

  Bati of an Olexographic printing machine with an individual counterpressure cylinder (9 to 14) and comprising one or more printing units (3 & 8), characterized in that it is flexible at each module (16 to 19, 69 and 70) corresponding to a printing unit and its cylinder of

associated counterpressure.

  2. Frame according to claim 1, characterized in that a module (16 to 19, 69 and 70) is composed of two walls (20) arranged parallel and symmetrically on either side of the longitudinal median plane of the support, such as a printing tape (15) made of paper, plastics, or the like, said walls (20) being secured between them by means of sleepers (21, 22, 23) and carrying

  media means (38) of a printing unit (3 to 8).

  3. Frame according to claim 2, characterized by the fact.

  that the sleepers (22,23) located on the side at the passage of the strip (15) are of round section, the cross member (21) associating the walls (20) of a module (16 to 19, 69 and 70) at the printing group (3 to 8) being of increased resistance for

ensure transverse stiffness.

  4. Frame according to claims 1 and 2, characterized by

  the different modules (16, 17, 69) or (18, 19, 70) are superimposed and each comprise means (39) ensuring their positioning relative to one another and

  connecting means (40) to make them integral.

  5. Frame according to claim 4, characterized in that the means (39) for positioning between them, the modules (16,17,69) and (18,19,70) superimposed consist of a key (41 ) being housed in a groove (42) machined on the upper edge (43) of the walls (20) of a module and cooperating with a groove (44) arranged in the lower edge (45) of the walls (20) of a module coming from

  position immediately above.

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  6. B & ti according to claim b, characterized in that each of the walls (20) of a module (16 to 19, 69 and? 0) comprises, danris its upper edge (43) and in its lower edge (45) at least one groove, respectively, (42), (44) for engaging a key (41). 7. Frame according to claim 5, characterized in that the keys (41) are positioned in the grooves (42,44) of the walls (20) in a direction perpendicular to the plane of the latter and comprise, at their ends (47). , 48) threaded orifices (49, 50) in which are screwed bolts (51, 52) provided with a washer (53, 54) bearing respectively on the inner (55) and outer (56) faces. walls (20) of two superposed modules to ensure

their vertical alignment.

  8. Frame according to claim 5, characterized in that the keys (41) are secured to at least one module (16 to 19, 69 and 70) by means of a fastener

(46) such as a screw.

  9. Frame according to claim 4, characterized in that the connecting means (40) are constituted by removable fasteners, such as screws (57) inserted into orifices (58) machined in the lower edge (59). ) openings (60,61) arranged in the inner portion (62) of the modules (16 to 19, 69 and 70), these removable fasteners cooperating with the walls (20) of a module placed

immediately below.

  10. Frame according to claims 5 and 9, characterized by

  the fact that the modules (16 & 19, 69 and 70) comprise means (71) for shifting them in a horizontal direction, said means (71) consisting, on the one hand, in arranging the grooves (42), (44), machined, respectively, in the upper edge (43) and inside (45) of the walls (20), near the internal lateral edge (72) of the latter and, secondly, in the embodiment of additional orifices (75, 76) in the inner edge (59) of the openings (60, 61) practiced with the lower part (62) of the parols (20), these orifices (75, 76) serving for the passage through the fixing members removable, and respecting a deviation, with respect to the central orifice (58) corresponding S to the amplitude of the offset to be imparted between the modules (16 to

19, 69 and / 0).

  11. Frame according to claim 1, characterized in that it can adopt a symmetrical structure with respect to the median plane (64) transverse to the longitudinal axis of the strip (15) superimposed modules (16,17,69) and (18,19,70) disposed respectively on either side of said transverse median plane (64) resting on an emDase (65) and being covered with a cap (67), the latter contending with a uniEé

in the building 1.