EP0611240B1 - Printing machine, incorporating at least one double-displacement cylinder - Google Patents

Description

The present invention relates to a printing machine equipped with a plurality of cylinders and more particularly to a printing machine of the flexographic sheet-by-sheet type in which at least one cylinder, for example the screened cylinder or the back-pressure cylinder is completely retractable. by a double displacement of great amplitude.

In all printing machines, most of the cylinders are provided with displacement members allowing the spacing of the cylinders with respect to each other, in particular in the absence of sheets to be printed or in the case of adjustment of the machine. Such a spacing corresponds to a displacement of small amplitude.

A displacement of certain cylinders, of greater amplitude, is sometimes necessary, in particular when it is a question of changing one cylinder by another.

Multiple devices have already been proposed aiming to obtain a quick and easy change of certain cylinders. It can be a device external to the printing machine, for example in the form of a robot, such as that described in document EP 0 400 517. It can also be devices integrated into the printing machine. to print. Such a device aimed at the automatic change of cylinders of a flexographic printer is described in document FR 2 485 990. This device aims more particularly at the automatic change of plate cylinders and screened cylinders on a flexographic printer, the counter cylinder -pressure is common to several inking stations. It comprises gripping means capable of achieving a certain clearance in height of the cylinders, said gripping means cooperating with tilting raceways intended to ensure a linear translation of the cylinders, moving by gravity on the raceways until reaching a position where they are suitable for being taken up by hoists.

According to the applicant, the device described in this document FR 2 485 990 has a certain number of drawbacks. On the one hand it is very complex in terms of production, using a very large number of various mechanical components. On the other hand it is not fully automatic insofar as manual intervention is necessary to release the cylinder whose change is desired.

The aim set by the applicant is to provide a printing machine equipped with a plurality of cylinders and which comprises displacement means for at least one of said cylinders, which overcomes the aforementioned drawbacks.

This object is perfectly achieved by the machine of the invention which, in a manner known from document FR 2485990 comprises for a given cylinder first means of displacement from a first position corresponding to the working position to a second position and second means for moving from said second position to a third position; typically the shaft of said cylinder, with double displacement, comprises an individual drive motor and cogwheels at its two ends, and the second displacement means comprise a set of two racks in which said cogwheels can mesh , so that the displacement of said cylinder from the second to the third position is obtained by the rotation of said drive motor.

It is understood that, according to the invention, the individual drive motor of the double displacement cylinder remains integral with said cylinder during the two successive displacements of the latter. It is in particular an electronic servo motor, of the brushless type.

Of course, it had already been proposed to equip the cylinders of a printing machine with individual drive motors, in particular in document FR 2 553 032. However, such a motor had never been used to produce, as is in the case of the present invention, a displacement of the cylinder during the retraction thereof relative to its working position.

Preferably each end of the shaft of the double displacement cylinder is integral with a slide and the first displacement means comprise a first set of two slides delimiting the path of said slides between the first and second position and are capable of simultaneously moving the two slides in said slides.

According to this particular embodiment, the first displacement of the cylinder is a linear displacement between the first and the second position. In the case of a sheet-by-sheet flexographic printing machine, this first linear displacement is a vertical displacement, both for the screened cylinder and for the counter-pressure cylinder.

According to a first variant, each slide comprises a rack and the first displacement means comprise a motor driving a pinion which is capable of meshing with said rack.

According to a second variant, the two slides have a notch and the first displacement means comprise a motor driving two vertical ball screws, each screw having a length at least equal to the distance between the first and the second position and being able to pass through the notch, so that the nut of the ball screw carries a slider between the first and the second position and in that the nut of the screw can come out of the notch and be released from the slider between the second and the third position.

Advantageously, the printing machine according to the invention is with automatic change of screened cylinder. In this case, it comprises at least two double displacement screened cylinders, one being in a fourth so-called storage position while the other is in the first so-called working position; moreover, it comprises third means of displacement of said cylinders from a fourth to a second position, said displacement taking place in the same direction as that of displacement from the second to the third position. The screened cylinder is changed by actuating the first, second and third displacement means so that the screened cylinder which is in the working position moves to the second and then to the third position and in that the cylinder which is in the fourth so-called storage position goes to the second and then to the first position.

Advantageously the printing machine is washing automatic plate cylinder. In this case it comprises a double-displacement backpressure cylinder placed in the working position under the plate cylinder, a mobile device for washing the plate cylinder and means for moving said washing device which are suitable for bring close to the plate cylinder when the back pressure cylinder has moved from the first to the third position.

Preferably, the mobile washing device is, when the back-pressure cylinder is in the working position, placed in a housing which is located near the second position; the means for moving said washing device then comprise the first means for moving the back-pressure cylinder. In this case, it is the same displacement means which both retract the back-pressure cylinder between the first and second positions and which position the mobile washing device from its housing to its location in the vicinity and under the plate cylinder.

Advantageously, the printing machine according to the invention is with automatic retraction of the back-pressure cylinder and of the system for transferring the material to be printed, integral with said back-pressure cylinder. In this case the machine also includes support rods on which the transfer system is supported and pivots on itself during the passage of the back-pressure cylinder from the first to the third position.

• la figure 1 est une vue de côté de la machine à imprimer à deux cylindres tramés à changement automatique,
• les figures 2 à 7 illustrent les différentes étapes réalisant le changement automatique desdits cylindres tramés, conformément à la figure 1,
• la figure 8 est une vue de côté de la machine à lavage automatique du porte-cliché et à escamotage de l'ensemble cylindre de contre-pression et système de transfert, le dispositif mobile étant en position d'attente,
• les figures 9 à 12 montrent les différentes étapes de mise en place du dispositif de lavage et d'escamotage de l'ensemble cylindre contre-pression / système de transfert.

The present invention will be better understood on reading the description which will be given of two exemplary embodiments of a flexographic sheet-to-sheet printing machine with a double displacement cylinder: the first example relates to the automatic change of screened cylinder, and the second example concerns simultaneously the retraction of the assembly constituted by the back-pressure cylinder and the sheet transfer system, feeding the machine, as well as the automatic washing of the plate cylinder. These two examples are illustrated by the accompanying drawing in which:

• FIG. 1 is a side view of the printing machine with two screened cylinders with automatic change,
• FIGS. 2 to 7 illustrate the different steps carrying out the automatic change of said screened cylinders, in accordance with FIG. 1,
• FIG. 8 is a side view of the automatic washing machine for the plate holder and with retraction of the counter-pressure cylinder and transfer system assembly, the mobile device being in the standby position,
• Figures 9 to 12 show the different steps of setting up the washing and retracting device of the cylinder against pressure / transfer system.

The printing machine which will be discussed in the examples below is a sheet-fed flexographic printer in which the plate cylinder 1, fixed, occupies a central position while the back-pressure cylinder 2 is located below of the plate cylinder 1 and the screened cylinder 3 above it. This choice is not, however, limiting of the invention but simply allows it to be illustrated.

The screened cylinder is the cylinder which brings the desired ink dose to the plate cylinder. It has on its surface a multitude of cells. The ink deposited on the screened cylinder 3 is scraped with a rubber cylinder 4 or possibly with a doctor blade in order to leave on its surface an amount of ink corresponding to the volume of its cells. This ink is then transferred to the plate cylinder 1, against which the screened cylinder 3 is applied. The sheet to be printed passes between the plate cylinder 1 and the back pressure cylinder 2 so that the ink deposited on the plate is applied to said sheet.

In order to obtain good quality prints, it may be necessary to modify the quantity of ink added to the plate depending on the type of printing, for example flat or text in fine print, or the type of cardboard, for example. example kraft or coated cardboard. Such a modification of the quantity of ink can only be done by changing the screened cylinder. The printing machine represented in FIG. 1 shows the different elements making it possible to automatically change the screened cylinder.

For simplification, there has been shown and we will only describe the change between two screened cylinders 3 and 3 '. In FIG. 1, the first screened cylinder 3 is in the working position while the second screened cylinder 3 'is in the so-called storage position.

The shaft 5, 5 'of each of the two screened cylinders 3, 3' is rotated by an electronic servo motor, of the brushless type, not shown. In addition, the shaft 5, 5 'also includes, towards each of its ends, a toothed wheel 6, 6'. Finally, the ends of said shafts 5, 5 'are secured to slides 7, 7'.

The automatic change of the screened cylinder 3 is carried out by a first movement from the working position to a second intermediate position, illustrated in FIG. 2. This first movement, linear and vertical, is obtained by means of slides, 8, 9, which delimit the path of the slides 7 between the first and the second position.

There is also provided, below each slide 7, in the working position, a transfer piece 10, capable of moving between the two slides 8, 9, at the same time as the slides 7. This transfer piece 10 is secured to the corresponding slide 7 so as to allow the vertical movement of the part 10 by driving the slide 7. This connection can result from the presence of an assembly system of the T-slot type which achieves this connection when the movement is vertical but which must allow the separation of the slide 7 and the transfer piece 10 when the movement will be horizontal as will be explained below.

The slide 7 as well as the transfer piece 10 laterally support a rack respectively 11, 12, the two racks being in the extension of one another when the slide 7 and the transfer piece 10 are secured.

The two vertical slides 8, 9 are extended, towards their ends opposite to the plate cylinder, each by a horizontal slide 13 and 14 respectively. In addition, a rack 15 extending horizontally is arranged. above the two horizontal slides 13, 14 and the space between these two slides corresponding to the spacing of the two vertical slides 8, 9.

The printing machine further comprises, opposite each slide 7, a toothed wheel 16, driven in rotation by a gear motor not shown. This toothed wheel 16 is arranged so as to always be in engagement with the teeth of the rack 11, 12 either of the slide 7 or of the transfer part 10.

The automatic change of the screened cylinder is obtained in accordance with the various steps illustrated in FIG. 1 in FIG. 7.

In Figure 1 there is shown the first screened cylinder 3 in the working position, applied against the plate cylinder 1, while the second screened cylinder 3 'is in the storage position, its slides 7' resting on one of the two horizontal slides 13, 14 at the end thereof. In this storage position, which we will call fourth position, the toothed wheel 6 'of the second screened cylinder 3' is engaged on the teeth of the rack 15.

In Figure 2, there is shown the displacement of the first screened cylinder 3 from the working position to an intermediate position, which we will call second position.

This displacement is obtained by controlling the rotation of the gear motor driving in rotation the toothed wheel 16 in the direction of the arrow F. The toothed wheel 16 meshes first in the rack 11 of the slide 7 then in the rack 12 of the transfer part 10, this rotation causes the vertical displacement along the arrow G of the assembly constituted by the slide 7, the first screened cylinder 3 and the transfer part 10.

The second position is reached when the toothed wheel 6 carried by the shaft 5 of the first screened cylinder 3 is applied in the teeth of the horizontal rack 15. In this second position the base of the slide 7 is tangent to the upper face of the horizontal slides 13, 14.

In FIG. 3, the second displacement of the first screened cylinder 3 from second to third position, the latter corresponding to the storage position of this first screened cylinder. This movement is obtained by controlling the motor with electronic servo drive of the shaft 5 of the first screened cylinder 3, in the direction of the arrow I. The toothed wheel 6 meshing on the horizontal rack 15, this rotation causes l 'assembly constituted by the slide 7 and the first screened cylinder 3 in the direction of the arrow H. During this movement the base of the slide 7 is supported and slides on the surface of the horizontal slide 14.

During this movement, the transfer part 10 remains in the position which was hers in FIG. 2, that is to say when the first screened cylinder was in the second position. Indeed the slide 7 is detached from the transfer part 10, by sliding one relative to the other of the assembly system of the T-slot type.

Figure 4 shows the two screened cylinders 3, 3 'in the storage position.

Figures 5 to 7 show the steps for moving the second screened cylinder 3 'from its storage position to the working position. These steps are very similar to those just described.

The displacement of the second screened cylinder 3 'from the fourth to the second position is effected by rotation of the electronically controlled motor driving the toothed wheel 6' mounted on the shaft 5 'of said second screened cylinder 3' in the direction of the arrow J. During this movement, the slide 7 ′ of the second screened cylinder 3 ′ comes to join with the transfer part 10 which had remained in the same position.

When this second screened cylinder 3 'is in the second position, as illustrated in FIG. 6, the gear motor drives in the direction of the arrow F' the toothed wheel 16, which first meshes in the rack 12 of the transfer part 10 then in the rack 11 'of the slide 7' so as to drive the second screened cylinder 3 'from the second to the first position.

As can be seen in Figure 7, the second cylinder screened 3 'which was initially in the fourth storage position is moved to the working position while the first screened cylinder 3 which was in the working position has been placed in the third storage position.

The embodiment which has just been described has been given by way of non-exhaustive example. This is a particularly simplified mode since it only has two screened cylinders 3.3 ′. It would be possible to envisage a plurality of screened cylinders in the storage position. In this case it would be necessary to extend the horizontal slides 13 and 14 in order to allow the juxtaposition on the same horizontal slide 13 or 14 of several cylinders.

Of course, it is understood that the drive motors of the screened cylinders 3, 3 ′ and of the toothed wheel 16 are connected to an electronic control system, making it possible to synchronize the movements as described above. More particularly, a particular synchronization must be implemented so that when the cylinder arrives in the second position, the corresponding toothed wheel 6 comes to perfectly engage in the teeth of the rack 15.

In addition, in the case of more than two screened cylinders, it would be necessary to ensure that the storage of the screened cylinders on the horizontal slides 13, 14 is always carried out in the same order, in order to avoid tangling of the cables. for connecting the drive motors of the screened cylinders. Such storage can be obtained by moving certain woven cylinders from a horizontal slide 13 to the other 14 by using, as a basis for movement, the upper face of the slide 7 of a woven woven cylinder, said face being in the alignment of the two horizontal slides 13, 14.

In the second example of embodiment, illustrated by FIGS. 8 to 12, the printing machine is with automatic washing of the plate cylinder 1 and with retraction of the assembly 17 constituted by the back pressure cylinder 2 and the transfer system. leaves.

Washing of the plate cylinder 1 is generally carried out manually when the machine is stopped, or else by dismantling the plate cylinder 1 and placing it in a special washing installation.

Thanks to the double displacement cylinder system according to the invention, it becomes possible to ensure an automatic washing of the plate cylinder 1, after complete retraction of the back pressure cylinder 2.

In the embodiment which will be described, the back-pressure cylinder 2 is integral with the system for transferring the material to be printed. There is therefore a transfer assembly 17 which consists of the back-pressure cylinder 2, of the electronically-controlled motor 18, which drives the shaft 19 of the back-pressure cylinder 2, a set of belts 20, possibly notched, mounted in a loop around two drive rollers 21, 22, the roller 22, located near the back pressure cylinder 2 also being driven by the motor 18. The set of belts 20 could be replaced by a succession of drive rollers.

As can be seen in FIG. 8, the set of belts 20 conveys the printed material, sheet by sheet, from the previous station 23.

Optionally, the set of belts 20 can be surmounted by an infrared device 24 intended for drying the ink in the case where the preceding station 23 is itself a printing station.

According to the invention, the shaft 19 of the back pressure cylinder 2 supports at each of its ends on the one hand a toothed wheel 25 and on the other hand a slide 26, which in this case is a rectangular metal plate .

The retraction of the back pressure cylinder 2 is achieved by a first vertical displacement, by means of vertical slides 27, 28 delimiting the path of the slide 26 between the first working position of the back pressure cylinder 2 and the second intermediate position. A second movement, between said second position and a third storage position is achieved by two horizontal slides 29, 30 defining the path of the slide 26 between these two positions.

The drive of the back pressure cylinder 2 during the first movement, and correspondingly of the transfer assembly 17, is obtained by means of a ball screw system, driven by a motor, the nut of the ball screw supporting the slide 26 between the first and the second position. Preferably, the slide 26 is provided with a notch into which the nut of the ball screw penetrates during this movement so as to ensure its blocking. The arrangement of the notch is such that when the slide is driven from the second to the third position, the nut of the ball screw comes out of the notch, separating the transfer system 17 from the ball screw system.

The machine is also equipped with horizontal racks 31, located in the area between the two horizontal slides 29 and 30.

The mobile washing device 32 consists of a tank for recovering the washing liquid and an assembly comprising rotary brushes with axial displacement and water jets. It is of course possible to equip this mobile washing device 32 with all mechanical, pneumatic, ultrasonic, etc. means allowing washing of the plate cylinder 1 to be carried out in a short time.

The mobile washing device 32 is, when the back-pressure cylinder 2 is in the first working position, located in a housing 33 which is a hollow part of the base 34 of the machine.

The vertical movement of the washing device 32 from its housing 33 to the first position, that is to say in the immediate vicinity of the plate cylinder 1 is preferably obtained by the same means as those used to ensure the vertical displacement of the back pressure cylinder 2.

To do this, the washing device 32 is equipped, at each of its ends with a slide, not shown, capable of moving, like the slide 26 of the back pressure cylinder 2 between the vertical slides 27, 28, to carry out the automatic washing of the plate cylinder 1.

In the exemplary embodiment where the back-pressure cylinder 2 is integral with the transfer assembly 17, the retraction of the set of belts 20 is obtained also thanks to two support rods 35, 36 whose position and role will be explained during the description which follows of the various stages allowing the complete retraction of the transfer system 17 and automatic installation of the washing device 32.

In Figure 8 there is shown the transfer system 17 in its working position, namely the back pressure cylinder 2 being applied to the plate cylinder 1 and the set of belts 20 being upstream and in horizontal alignment of the line of tangency between the plate cylinder 1 and the back pressure cylinder 2.

So that the set of belts 20 is not completely cantilevered with respect to the ball screw system which keeps this assembly 17 in position, rods or rollers of support 37 have been arranged at the previous station 23.

In Figure 9 there is shown the first movement of the back-pressure cylinder 2 from the first working position to the second position, obtained by rotation of the screw of the ball screw system and the correlative movement of the slides 26 between the slides 27, 28.

During the first part of this movement, the upstream end of the set of belts 20 was supported by a support rod 35, placed on the frame of the previous station 23.

In the second part of this same first movement, the set of belts 20 is supported by a second support rod 36 fixed to the frame of the printing machine.

Thus when the back-pressure cylinder 2 reaches the second position as illustrated in FIG. 10, the set of belts 20 makes a substantially 45 ° angle with respect to the horizontal.

The complete retraction of the transfer system 17 is achieved by the second displacement of the back pressure cylinder 2 between the second intermediate position and the third standby position.

This second movement is obtained by the rotation of the shaft 19, driven by the electronic servo motor 18.

When the back pressure cylinder 2 arrives at the second position, the gear 25 is engaged on the teeth of the horizontal rack 31. Thus during the rotation of the shaft 19 in the direction of the arrow F, the gear 25 meshes on the rack 31 and moves thereon to the extreme position corresponding to the waiting position.

During this horizontal movement, the set of belts 20 remained in abutment on the rod 36, which resulted in a pivoting of the transfer system 17, so that the set of belts 20 is almost in the vertical position when the back-pressure cylinder 2 is in the third standby position, as shown in FIG. 11.

Once this second movement has been made, or possibly in masked time, the washing device is moved vertically between its low position where it is in its housing 33, to its high position where it is close to the plate cylinder. 1.

Such displacement can be obtained by independent means or, preferably, by the same means as those used to ensure the first vertical displacement of the back-pressure cylinder 2.

With regard to the ball screw system, in a first embodiment, the washing device 32 comprises a fork which is retractable between a retracted position and an extended position in which the ball screw penetrates between the arms of the fork at above the nut of the ball screw, the passage between the retracted position and the extended position of the fork being effected by the action of a limit switch when the counter-pressure cylinder arrives 2 in the third waiting position.

In a second embodiment illustrated by FIG. 12, the washing device 32 is mounted at each of its ends on slides 38 and the machine also includes a set of moving parts 39. As it appears on examining the figure 12, the moving part 39 is located below the level of the horizontal lower slide 30. It is further characterized by three shoulders 40, 41, 42, the first 40 being located at its front end while the other two shoulders 41, 42 are situated at its rear end and delimit between them a space capable of forming a housing for the slide 38 of the washing device 32.

In Figure 12 there is shown the position taken by the movable part 39 while the transfer system 17 is in the working position.

During the first movement, and for most of the second movement, the moving part 39 remains in this same position.

At the end of the second movement, the slide 26 supporting the pressure cylinder 2 comes to bear on the first shoulder 40 and pushes it back with it into the third waiting position. This correlatively causes the displacement of the movable part 39. The amplitude of the displacement of this part 39, and therefore the position of the first shoulder 40 relative to the third standby position, is determined so that, when said shoulder 40 is in this third position, the slide 38 of the washing device 32 is located directly above the vertical slides 27, 28.

Each slide 26 of the back-pressure cylinder 2 has a notch 43, substantially horizontal, open on the left side in FIG. 12. Each slide 38 of the washing device 32 has a notch 44, substantially horizontal, open on the right side. During the first vertical displacement from the first position to the second position, the nut of the ball screw 45 of the ball screw system is in the notches 43 of the slides 26 and supports the back-pressure cylinder 2. During the second displacement , horizontal, of the slides 26 from the second to the third position, the nut of the ball screw 45 remains in place, coming out of the notch 43. When the slides 38 of the washing device 32 move to the right, towards plumb with the vertical slides 27, 28 the nut of the ball screw 45 enters the notch 44. The ball screw system can then drive the washing device 32 from the second to the first position.

Claims (13)

1. Printing machine equipped with a plurality of cylinders, and comprising, for a given cylinder (3, 2), first means for displacement from a first position corresponding to the work position to a second position and second means for displacement from said second position to a third position, characterized in that the shaft (5,19) of said double-displacement cylinder (3, 2) comprises an individual drive motor and toothed wheels (6, 25) at its two ends, and in that the second displacement means comprise a set of two racks (15, 31) in which the toothed wheels (6, 25) may mesh so that the displacement of said cylinder (3, 2) from the second to the third position is obtained thanks to the rotation of the drive motor of the shaft (5, 19) of said cylinder.
2. Printing machine according to claim 1, characterized in that each end of the shaft of the double-displacement cylinder is fast with a slide block (7, 26), in that the first displacement means comprise a first set of two slideways (8, 9 and 27, 28) defining the path of said slide blocks between the first and the second positions and are adapted simultaneously to displace said two slide blocks in said slideways.
3. Printing machine according to claim 2, characterized in that each slide block (7) comprises a rack (11), and in that the first displacement means comprise a motor driving a pinion (16) adapted to mesh on said rack (11).
4. Printing machine according to claim 2, characterized in that each slide block (26) comprises a notch (43), and in that the first displacement means comprise a motor driving two vertical ballscrews, each screw having a length at least equal to the distance between the first and the second position and being adapted to pass in the notch (43), so that the nut of the ballscrew (45) supports the slide block between the first and the second positions, and in that the nut of the ballscrew (45) may emerge from the notch (43) and be disengaged from the slide block between the second and the third positions.
5. Printing machine according to claim 1 with automatic change of screened ink rollers, characterized in that it comprises at least two screened ink rollers (3, 3') with double displacement, one being in the fourth, so-called storage position, whilst the other is in the first, so-called work position, and in that it comprises third means for displacement of said screened ink rollers (3, 3') from the fourth to a second position, which is in the same direction as the displacement from the second position to the third position, the change of screened ink rollers (3, 3') being effected by actuating the first, second and third displacement means so that the roller (3) which is in work position passes to the second then the third position and in that the roller (3') which is in the fourth, storage position passes to the second then to the first, work position.
6. Printing machine according to claims 1, 3 and 5, comprising a plate cylinder, characterized in that, as the screened ink roller (3) is placed above the plate cylinder (1), the first direction is vertical, in that the third displacement means also comprise said set of racks (15) in which the toothed wheels (6') of said screened ink roller (3') which is in the fourth position may mesh, in that it comprises a second and a third set of horizontal sideways (13, 14) extending respectively between the second and the fourth and between the second and the third positions, in that it comprises two transfer pieces (10), with rack (12), arranged so that the two transfer pieces (10) support the slide blocks (7) of the screened ink roller (3) in work position and in that the passage of said roller (3) from the first to the second position is effected by drive of the pinions (16) meshed on the racks (11, 12) of the slide blocks (7) then of the transfer pieces (10), and in that the passage of the rollers (3, 3') from the second to the third or from the fourth to the second position is effected by drive of the toothed wheels (6, 6') of the rollers (3, 3') meshed on the set of racks (15) and by slide of the slide blocks (7, 7') on the second or the third set of horizontal slideways (13, 14).
7. Printing machine according to claim 6, characterized in that a screened ink roller (3) may pass from the third position to the fourth, storage position by displacement on the horizontal slideways (13, 14) and on the upper face of the slide blocks (7) of another screened ink roller (3') which is in standby position, said upper face being in line with the horizontal slideways (13, 14).
8. Printing machine according to claim 1, characterized in that it comprises a double-displacement impression cylinder (2) placed in work position beneath the plate cylinder (1), a mobile device (32) for washing the plate cylinder (1) and means for displacement of said washing device adapted to bring it near the plate cylinder (1) when the impression cylinder (2) has passed from the first to the third position.
9. Printing machine according to claim 8, characterized in that the first direction is substantially vertical, and in that, when the impression cylinder (2) is in work position, the mobile washing device (32) is placed in a housing (33) which is located near the second position, and in that the means for displacement of said washing device comprise the first means for displacement of the impression cylinder.
10. Printing machine according to claims 4 and 9, characterized in that the means for displacement of the washing device (32) comprise a fork which is fast with said device and which is retractable between a retracted position and an extended position in which the ballscrew (45) penetrates between the prongs of the fork above the nut of the ballscrew, the passage between the retracted position and the extended position of the fork being effected under the action of an end-of-stroke contactor upon arrival of the impression cylinder (2) in the third position.
11. Printing machine according to claims 4 and 9, characterized in that the means for displacement of the washing device (32) comprise slide blocks (38) provided with a notch (44) and a mobile piece (39) with three shoulders (40, 41, 42) arranged so that, upon displacement from the second to the third position, the slide block (26) of the impression cylinder (2) pushes the first shoulder (40) and drives the mobile piece (39) on a second position such that the slide block (38) which is housed between the other two shoulders (41, 42) is located plumb with the two vertical sideways (27, 28), the nut of the ballscrew (45) of the ballscrew system having penetrated in the notch (44).
12. Printing machine according to one of claims 1, 8, 9, 10 or 11, characterized in that it comprises a double-displacement impression cylinder (2) and a system (17) for transferring the material to be printed which is rigidly fast with the impression cylinder, and in that it further comprises abutment rods (35, 36) on which the transfer system abuts and pivots on itself upon passage of the impression cylinder from the first to the third position.
13. Printing machine according to claim 12, characterized in that, as the transfer system has a substantially horizontal direction when the impression cylinder is in work position, the abutment rods (35, 36) are disposed so that the transfer system has a substantially vertical direction when the impression cylinder is in the third position.

Images