EP2616243A1

EP2616243A1 - Device for printing by stamping

Info

Publication number: EP2616243A1
Application number: EP11757166.1A
Authority: EP
Inventors: Christophe De Gaillande
Original assignee: Bobst Mex SA
Current assignee: Bobst Mex SA
Priority date: 2010-09-16
Filing date: 2011-08-30
Publication date: 2013-07-24
Anticipated expiration: 2031-08-30
Also published as: WO2012034645A1; BR112013006172B1; AU2011301409B2; JP2013542866A; US20130160663A1; PL2616243T3; RU2537283C2; TW201219229A; EP2616243B1; US8881649B2; CN103097137B; JP5698364B2; CN103097137A; RU2013117091A; TWI474930B; AU2011301409A1; ES2587446T3; KR101453702B1; KR20130064112A; BR112013006172A2

Abstract

Device (300) for printing elements in sheet form (10), comprising a platen press (310) for applying to each sheet (10), by stamping, some coloured or metallized film that comes from at least one stamping strip (410), conveyor means using a succession of gripper bars (610) to move each sheet (10) individually through the platen press (310), and a blower member (320) to separate each stamping strip (410) from each sheet (10) leaving the platen press (310). The blower member (320) is mounted so that it can be moved between a work position in which it is able to operate from the transit zone in which the gripper bars (610) travel at the exit of the platen press (310), and a withdrawn position in which it lies away from said transit zone.

Description

STAMP PRINTING DEVICE

The present invention relates to a device for printing sheet-shaped elements by stamping.

The invention finds a particularly advantageous, but not exclusive, application in the field of manufacturing packaging for the luxury industry.

It is known to print texts and / or patterns by stamping, that is to say to deposit by pressure on a sheet-like support, colored or metallized film from one or more strips to be stamped. commonly referred to as metallized strips. In the industry, such a transfer operation is usually carried out by means of a vertical platen press, in which the printing media are introduced sheet-by-sheet, while the feeding of strips to be stamped takes place keep on going.

In a standard platen press, the stamping conventionally takes place between a fixed platen extending horizontally, and a platen movably mounted in displacement in a vertical reciprocating motion. This type of press being generally automated, means of transport are provided to bring one by one each sheet between the plates. In practice, it is usually a series of gripper bars each of which, in turn, grip a sheet at its front edge, before pulling it between the two decks when the latter are sufficiently spaced apart.

A tape stamping is schematically composed of a support film type polyester, on which is secured a pigmented layer via a layer of wax. The outer face of this pigmented layer is coated with a hot melt adhesive layer. As in the case of sheets, the feed of the belt press is traditionally automated, by means of a drive system able to unroll and circulate each of said bands following a well defined scrolling path, which pass especially through the platen press. Generally, such a tape drive system combines a series of return rods that are implanted along the running path to guide the webs movement, with a plurality of feed trees positioned downstream of said path to respectively drive each of said strips moving.

At each machine cycle, a sheet is fed between the two plates, while the strips to stamp are advanced and then immobilized at the same place. The platen press is then closed again. This closure generates pressurization of the sheet and strips between a plurality of plates and counterparts, arranged vis-a-vis respectively on each of the plates. The clichés or the counterparts being heated, it then occurs a wax melting and taking the hot melt glue only at their contact areas, thereby achieving the transfer of pigments bands to the sheet according to a given pattern.

In practice, it is unfortunately observed that during the reopening of the platen press after stamping, the various polyester films naturally tend to remain attached to the sheet. To overcome this difficulty, it is known to force the separation between the strips to punch and the sheet by directing a jet of air under pressure at their junction. For this, a blower is generally used which is fixed directly to the outlet of the platen press, and which implements blowing nozzles positioned closer to the plane of movement of the sheets, that is to say directly in the zone of passage of the gripper bars.

Such an arrangement, however, has the disadvantage of requiring the use of clamp bars equipped with clamps at the top, that is to say clamps which are shaped to grip each sheet substantially at the upper face of the bar of pliers. However it is known that this type of clamps does not ensure optimum transport of the sheets through the platen press. The particular form of. clamps at the top actually leads to move each sheet away from the movable bottom plate, that is to say, without being supported to remain substantially horizontal. During its deceleration, the sheet will naturally have a tendency to deform, resulting in the occurrence of a wrinkling phenomenon which is particularly detrimental to the quality of printing.

Also, the technical problem to be solved by the object of the present invention is to provide a device for printing sheet-shaped elements, comprising a platen press for depositing on each sheet by stamping, colored film or metallized material from at least one stamping strip, means of transport using a succession of gripper bars for individually moving each sheet through the platen press, and a blower member for separating each strip stamped from each sheet coming out of the platen press, printing device which would avoid the problems of the state of the art by offering both optimal transport of the sheets through the platen press, and a perfect separation of the strips after stamping.

The solution to the technical problem posed consists, according to the present invention, in that the blower member is mounted movably in displacement between a working position in which it is able to operate from the passage zone in which the clamp bars circulate. at the outlet of the platen press, and a withdrawal position in which it stands away from said passage zone.

It should be noted that the working position here constitutes an optimal operating position, without necessarily being the only position in which the blower member is able to operate. This means in other words that in the context of the invention, it is perfectly possible to operate the blower member in other positions, including those between the work position in question and the position withdrawal.

It is also understood that the withdrawal position designates for its part any positioning of the blower member, which allows free movement of the clamp bars at the outlet of the platen press. If in theory, the locations corresponding to this criterion appear numerous, in practice, the withdrawal position will be advantageously established in depending on the space available within the stamping machine, and the kinematics chosen to move the blower means.

In any event, the invention as thus defined has the advantage of being compatible with the use of clamp bars provided with clamps at the bottom, that is to say clamps which are shaped to grasp each sheet substantially at the underside of the clip bar. However, it is known that this type of clamp is extremely well suited for transporting sheets through the platen press. The particular shape of the clips at the bottom makes it possible to translate each sheet as close as possible to the movable bottom plate. The latter can then advantageously play the role of support, supporting the sheet substantially horizontally throughout its movement. It is thus possible to avoid any risk of wrinkling, and to obtain a precise positioning of the sheet despite the strong deceleration it will undergo just before its immobilization between the plates of the press. In the end, this makes it possible to significantly improve the print quality, but also to increase the operating speed of the printing device.

The present invention further relates to the features which will emerge in the course of the description which follows, and which should be considered in isolation or in all their possible technical combinations.

This description, given by way of non-limiting example, is intended to better understand what the invention is and how it can be achieved. It is also given with reference to the appended drawings in which: Figure 1 illustrates a gilding machine in which is integrated a printing device according to the invention.

Figure 2 shows in detail the integration of the blower member in the printing device.

Figures 3 is a view similar to Figure 2, but with the blower member placed in a so-called release position.

Figures 4 shows in detail the integration of a return member which is also provided with the printing device.

Figures 5 to 10 illustrate at the output of the platen press, the main phases of the kinematic operation of the printing device object of the invention.

Figure 5 shows a first phase of operation during which the stamping takes place.

Figure 6 shows a second phase of operation which corresponds to the opening of the platen press.

FIG. 7 represents a third operating phase of which one particularity is the maximum opening of the platen press.

Figure 8 illustrates a fourth phase of operation which is characterized in particular by the departure of the gripper bar.

Figure 9 shows a fifth phase of operation corresponding to the arrival of a new bar clamps within the platen press.

Figure 10 shows a sixth phase of operation during which the new bar clamps in turn out of the platen press. For the sake of clarity, the same elements have been designated by identical references. Likewise, only the essential elements for understanding the invention have been represented, and this without regard to the scale and in a schematic manner.

Figure 1 shows a printing machine 1 which is intended for the personalization of cardboard packaging for the luxury industry. Commonly called gilding machine, this printing machine 1 is conventionally composed of several work stations 100, 200, 300, 400, 500 which are juxtaposed but interdependent one by one to form a unitary unit able to process a succession of supports in the form of a sheet 10, 20. There is thus a feeder 100, a margin table 200, a printing device 300, a feed and recovery station 400, and a receiving station 500. Means transport 600 are further provided for individually moving each sheet 10, 20 from the output of the margin table 200 to the receiving station 500, including through the printing device 300.

The different parts 100, 200, 300, 400, 500, 600 of the printing machine 1 being perfectly known from the state of the art, they will not be described in detail here, both in terms of their structure and their operation.

In this particular embodiment, selected solely by way of example, the feeder 100 is supplied by means of a succession of pallets on each of which a plurality of cardboard sheets 10, 20 are stacked. successively removed from the top of the pile by a suction gripping member which transports them to the directly adjacent margin table 200.

At the level of the margin table 200, the sheets 10, 20 are laid by the suction gripper, that is to say placed one after the other so as to overlap partially. The entire web is then moved along a platen 210 toward the printing device 300 by means of a belt transport mechanism. At the end of the web, the top sheet 10 is systematically accurately positioned by means of front and side catches.

The workstation located immediately after the margin table 200 is therefore the printing device 300. The latter has the function of depositing on each sheet 10, 20, by hot stamping, the metallized film which is derived from a single stamping tape 410 in this embodiment. It uses for this a platen press 310 within which the stamping operation operates conventionally, between a heated upper platen 311 which is fixed, and a lower platen 312 which is mounted movably in movement according to a movement vertical back and forth.

Downstream of the printing device 300 is the tape feeding and recovery station 400. As its name indicates, this station plays a dual role since it is responsible for ensuring both the power supply. machine stamped belt 410, and the evacuation of the same band once it used.

In this particular embodiment, the band 410 is conventionally stored in a wound form, around a supply coil 420 mounted press. Similarly, after its passage through the platen press 310, the band 410 is wrapped around a recovery spool 430 rotatably mounted.

Between its storage point and its point of recovery, the band 410 is driven in displacement by a drive system 440 which is able to circulate it over a given distance and following a determined path of travel which passes in particular through the platen press 310. This tape drive system 440 is mainly composed, on the one hand, of a series of deflection bars 441 which are located along the running path to guide the movement of the web 410, and on the other hand, the combination of a feed shaft 442 and a pressure roller 443 which are positioned downstream of said running path for driving said belt 410 in displacement.

The process of processing the sheets in the printing machine 1 is completed in the receiving station 500 whose main function is to repackage in sheets the sheets 10, 20 previously treated. For this, the transport means 600 are arranged to automatically release each sheet 10, 20 when the latter is found at the right of this new battery. Sheet 10, then falls squarely onto the top of the stack.

In a very conventional manner, the transport means 600 implement a series of clamp bars 610 which are movably mounted in transverse translation by means of two chain trains 620 arranged laterally on each side of the stamping machine 1. Each chain train 620 travels a loop that allows the gripper bars 610 to follow a path successively passing through the printing device 300, the feed and discharge station 400 and the receiving station 500.

FIG. 1 also shows that the printing device 300 has a blower member 320 which is capable of separating the stamping strip 410 from each foil 10, which has just undergone stamping, by generating a stream of air under pressure at their junction. In accordance with the object of the present invention, this blower member 320 is mounted movably in displacement between a working position and a retracted position. The assembly is arranged so that in the working position, the blower member 320 is able to operate from the passage zone in which the pliers bars 610 flow directly at the outlet of the platen press. 310, and that in the retracted position, said blower member 320 is disposed away from said passage zone. It is important to note that at this stage of the description, the mobility of the blower member 320 can in theory operate in any movement movement.

In this embodiment, the blower member 320 is schematically in the form of a hollow cross member 321 along which are distributed a plurality of blowing nozzles 322 transversely implanted. This crosspiece 321 is arranged parallel to the output edge of the platen press 310, so that the blowing nozzles 322 are oriented toward the outlet of the platen press 310.

According to a presently preferred embodiment of the invention, between the working position and the withdrawal position, the blower member 320 is mounted to move in translation along a planar path which is substantially orthogonal to the passage plane in which the sheets 10, 20 circulate inside the platen press 310. It is understood that once the plane trajectory in question can in theory be any, that is to say, be purely rectilinear or circular, be more generally curvilinear, or result from any combination of these movements.

Preferably, however, the mobility in translation of the blower member 320 is exerted here in a direction which is generally substantially oblique with respect to the passage plane in which the sheets 10, 20 circulate inside the press. The assembly is also arranged so that the oblique direction in question is oriented so that it goes closer to the platen press 310 as it approaches the plane. of leaves 10,20. This characteristic makes it possible to have more time to translate the blower member 320, which offers the possibility of optimizing the timing of the displacements of the various moving elements which are present at the output of the platen press 310. .

Particularly advantageously, the printing device 300 is provided with first guiding means 330 which are able to guide the movement of the blower member 320 between the working position and the retracted position.

In this embodiment, the blower member 320 is directly supported by the first guide means 330, by means of two structurally identical lateral mechanisms 331 which are arranged symmetrically on either side of the printing device 300, and which are respectively connected to each end of the hollow cross member 321.

As can be seen in FIG. 2, each mechanism 331 comprises a control bar 332 whose lower end is integral with the blower member 320. This control bar 332 is connected via two levers pivoting 333, 334 to a support 335 which is integral with the fixed upper plate 311 of the press 310, and which is composed of a fastener 336 and a stirrup 337. The assembly is arranged so that the control bar 332, the two pivoting levers 333, 334 and the support 335 define a deformable quadrilateral. FIG. 2 clearly shows that the upper lever 333 is shorter than the lower lever 334, so that the deformable quadrilateral is more similar here to a trapezium whose deformation will advantageously generate a mowing effect, that is to say a displacement of the blower member 320 in a substantially oblique and curvilinear translation movement.

According to another advantageous characteristic of the invention, the printing device 300 is also provided with first motor means 340 which are able to move the blower member 320 between the working position and the retracted position.

In this embodiment, the first motor means 340 generate the displacement of the blower member 320 by directly actuating the first guiding means 330. They are therefore adapted to the fact that the guiding is carried out at each end of the blower member 320, and this is why in accordance with Figure 2, a lateral drive mechanism 341 is associated with each lateral guiding mechanism 331.

Thus, at the level of each lateral drive mechanism 341, the first motor means 340 comprise a cam 342 which is integral with a transmission shaft 343 able to be rotated by an electric motor (not shown) of which the implementation is synchronized with the operating cycle of the platen press 310. The cam 342 cooperates by driving with a roller 344 which is rotatably mounted on the short lever 333. An elastic return means 345 is provided to ensure the contact between the roller 344 and the cam 342. This is in the present case a tension spring which is positioned between an upper anchorage point on the control bar 332 and a lower anchor point on the stirrup 337.

The assembly is arranged so that the elastic return means 345 permanently pulls the control rod 332 downwards, which causes the roller 344 to bear against the cam 342. Thus, when the shaft 343 rotates, the rotation of the cam 342 causes pivoting in one direction or the other of the short lever 333, which causes the movement up or down of the control bar 332, and consequently the rise or the descent of the blower member 320.

According to a feature of the invention visible in Figure 3, the blower member 320 is further capable of being moved into a release position in which it is remote from the output of the platen press 310. It is important to point out that in theory, the release position can be accessible indifferently from the working position and / or from the withdrawal position.

Particularly advantageously, the printing device 300 is provided with second guiding means 350 which are able to guide the movement of the blower member 320 in the disengagement position, that is to say between the position and / or the withdrawal position on the one hand, and the release position on the other hand.

As can be seen clearly in the figure

3, at the level of each support 335, the upper end of the stirrup 337 is connected to the fastener 336 by a pivotal connection, while its lower end is not rigidly attached to the upper plate 311 of the press 310. This means in other words that the support 335 is articulated, that is to say that the stirrup 337 is able to pivot relative to the fastener 336, and that the lower end of said stirrup 337 is able to bear against the upper plate 311, in this case via an eccentric 338. It should be noted that the presence of this eccentric 338 makes it possible to adjust the angular position of the stirrup 337 by relative to the fastener 336, and thus to adjust the position of the blower member 320 relative to the outlet of the platen press 310.

Nevertheless, it has been seen previously that each control bar 332 is pivotally mounted at the end of the short lever 333, and is also connected to the support 335 via the long lever 334 and the means elastic return 345 which both use pivotal connections. As a result, the control bar 332 will be able to pivot relative to the end of the short lever 333, since that the stirrup 337 will be pivoted relative to the fastener 336 (Figures 2 and 3). In this logic, each control bar 332, each short lever 333, each long lever 334 each articulated support 335, and each resilient return means 345 must be considered as components of the second guide means 350 within the meaning of the invention.

According to another advantageous characteristic of the invention, the printing device 300 is further provided with second motor means 360 which are able to move the blower member 320 into the disengagement position.

As in the case of the first motor means 340, the second motor means 360 are arranged to cause the movement of the blower member 320 by directly actuating the second guide means 350.

In this embodiment, the second motor means 360 are constituted by a pneumatic jack 361 whose ends are respectively connected, via pivot links, to the upper plate 311 of the press 310 on the one hand, and to a cross member 362 binder rigidly the two stirrups 337 on the other hand. Of course, any other known motor means could be used in an equivalent manner. For example, here we think of the combination of several pneumatic cylinders, one or more hydraulic cylinders or a linear electric motor.

According to another feature of the invention, the printing device 300 further comprises a return member 370 which is capable of guiding the stamping band 410 to the output of the platen press 310, and which is movably mounted in displacement between a close position and a distant position. The whole is arranged in such a way that, in a close position, the deflection member 370 is able to operate at least in part in the passage zone through which the gripper bars 610 travel at the outlet of the platen press 310. The purpose here is to maintain the tape stamp 410 in a plane allowing its free movement between the plates 311, 312 of the press 310. But the assembly is also arranged so that in the remote position, the body of 370 reference can still officer but away from the area of passage of the gripper bars 610. The objective is against here to let each band to stamp 410 substantially in contact with one of the plates 311, 312 of the press 310, in this case the fixed upper plate 311.

It is important to underline that in the context of the invention, when a strip to be stamped is substantially in contact with a platen, it means indifferently that it extends in the direct vicinity, that it is in actual contact, even that it is in pressure against said platen. Whatever the circumstances, this implies that it does not seem relevant to circulate the tape to be stamped because of a risk of deterioration much too important.

According to a presently preferred embodiment of the invention, between the close position and the remote position, the return member 370 is mounted to move in translation along a plane trajectory which is substantially orthogonal to the passage plane in which the sheets circulate. 10, 20 inside the platen press. Once again, it is understood that the plane trajectory in question can in principle be arbitrary. Preferably, the mobility in translation of the return member 370 is exerted in a direction which is generally substantially oblique with respect to the passage plane in which the sheets 10, 20 circulate inside the platen press. 310. The assembly is also arranged so that the oblique direction in question is oriented so that it goes closer to the platen press 310 as it approaches the plane of passage leaves 10,20.

Particularly advantageously, the printing device 300 is provided with third guide means 380 which are able to guide the displacement of the return member 370 between the close position and the remote position.

In this exemplary embodiment, the return member 370 is in the form of a cross member 371 which is arranged parallel to the output edge of the platen press 310. This return member 370 is directly supported by the third gear means. guide 380, in this case by means of two structurally identical lateral mechanisms 381 which are symmetrically implanted on either side of the printing device 300, and which are respectively connected to each of the ends of the crossmember 371.

As can be seen clearly in FIG. 4, each lateral guiding mechanism 381 comprises a control bar 382 at the lower end of which is fixed the return member 370. This control bar 382 is connected by intermediate of two pivoting levers 383, 384 to a support 385 which is integral with the fixed upper plate 311 of the press 310. Again, the assembly is arranged so as to that the control bar 382, the two pivoting levers 383, 384 and the support 385 form a deformable quadrilateral. And since the upper lever 383 is also shorter than the lower lever 384, the deformable quadrilateral in question is more similar to a trapezium whose deformation will naturally generate a mowing effect, that is to say a displacement of the returning member 370 in a substantially oblique and curvilinear translation movement.

According to another advantageous characteristic of the invention, the printing device 300 is further provided with third motor means 390 which are able to move the return member 370 between the close position and the remote position.

In this embodiment, the third motor means 390 cause the displacement of the return member 370 by directly actuating the third guide means 380. They are therefore adapted to the fact that the guidance operates symmetrically at each end of the Referring member 370, and therefore according to Figure 4, a lateral drive mechanism 391 is associated with each lateral guide mechanism 381.

Thus, at the level of each lateral drive mechanism 391, the first drive means 390 comprise a cam 392 which is integral with a transmission shaft 393 able to be rotated by an electric motor (not shown) of which the implementation is synchronized with the operating cycle of the platen press 310. The cam 392 cooperates by driving with a roller 394 which is rotatably mounted at the upper end of the control rod 382. resilient biasing means 395 is further provided to ensure contact between the roller 394 and the cam 392. In the present case, it is a compression spring which is positioned between an upper anchorage point on the support 385 and a lower anchor point at the bottom of the control bar 382.

The set is _. arranged so that the elastic return means 385 continuously pushes the control rod 382 downwards, which causes the roller 394 to bear against the cam 392. Thus, when the transmission shaft 393 rotates , the rotation of the cam 392 causes the upward or downward movement of the control bar 382 and thus ultimately the raising or lowering of the return member 370.

It may be interesting to temporarily stop the reciprocating movement of the return member 370, especially when the printing device 300 must be used to deposit holograms on the sheets 10, 20. In this case, it is well obviously essential that the return member 370 is immobilized in a position allowing it not to encroach in the passage area of the clamp bars, that is to say a position relatively close to the remote position. Anyway, in the context of the invention, such a temporary immobilization can be advantageously achieved by simply deactivating the third motor means 390, or by disengaging the third guide means 380 with respect to said third motor means 390.

Figures 5 to 10 illustrate at the output of the platen press 310, the main phases of the kinematics of operation of the printing device 300 object of the invention.

Figure 5 shows that during the stamping operation, the platen press 310 is closed with the movable bottom plate 312 placed logically at its top dead center (pmh). The clamp bar 610 is meanwhile motionless at its pmh, while the blower member 320 is off and at its pmh. The return member 370 is for its part simply its pmh.

According to FIG. 6, the opening of the platen press 310 is materialized by the descent of the movable platen 312, followed by that of the pliers bar 610. The blower member 320 is then activated and begins to move. lowering synchronously with respect to the gripper bar 610. The return member 370 also starts its own descent, but offset from the blower member 320 so as not to disturb the action of the latter .

As can be seen in FIG. 7, when the platen press 310 is fully open, the movable bottom platen 312 is at its bottom dead point (pmb). It is the same for the return member 370, which implies that the stamping strip 410 is then completely detached from the fixed upper plate 311, and can thus start to move forward. The blower member 320 has also reached its pmb, so that the nozzles 322 are placed at this time between the body of the clamp bar 610 and the sheet 10. The blower member 320 can then be deactivated, and the gripper bar 610 continues its descent.

When the gripper bar 610 finally reaches its pmb, it can then be driven in horizontal translation so as to extract the sheet 10 of the platen press 310 according to Figure 8. The return member 370 is still at its pmb, the stamping tape 410 continues to advance. The blower member 320 remains deactivated at its pmb.

FIG. 9 illustrates the arrival of a new gripper bar 610 within the platen press 310 which is always wide open, while the blower member 320 and the return member 370 are still at their respective pmbs. .

As can be seen in FIG. 10, as soon as the new gripper bar 610 is taken out of the platen press 310, it begins its ascent simultaneously with that of the movable bottom plate 312. In parallel with this, the blower member 320 and the return member 370 start their own elevations, while the stamping band 410 stops advancing. These different movements then continue until the complete closure of the platen press 310, according to FIG.

Of course, the invention more generally relates to any processing machine 1 of sheet-shaped elements 10, 20, which comprises at least one printing device 300 as previously described. One thinks in particular here of a gilding machine as that which served to illustrate the invention.

Claims

A printing device (300) for sheet-like elements (10, 20) comprising a platen press (310) for depositing on each sheet (10, 20) by stamping, colored or metallized film at least one stamping strip (410), conveying means (600) using a succession of clip bars (610) for individually moving each sheet (10, 20) through the platen press (310), and a blower member (320) for separating each stamping strip (410) from each sheet (10, 20) emerging from the platen press (310), characterized in that the blower member (320) is mounted mobile moving between a working position in which it is able to operate from the passage zone in which the clamp bars (610) circulate at the outlet of the platen press (310), and a withdrawal position in which it stands away from said passage area.

2. Printing device (300) according to claim 1, characterized in that between the working position and the retracted position, the blower member (320) is movably mounted in translation along a flat trajectory which is substantially orthogonal to the passage plane in which the sheets (10, 20) circulate within the platen press (310).

3. Printing device (300) according to one of claims 1 or 2, characterized in that between the working position and the retracted position, the blower member (320) is mounted movably in translation in a direction which is generally substantially oblique with respect to the passage plane in which the sheets (10, 20) circulate within the platen press (310), said oblique direction approaching said platen press ( 310) as it approaches said passage plane.

4. Printing device (300) according to any one of claims 1 to 3, characterized in that it comprises first guide means (330) adapted to guide the movement of the blower member (320) between the working position and the withdrawal position.

5. Printing device (300) according to any one of claims 1 to 4, characterized in that it comprises first motor means (340) adapted to move the blower member (320) between the working position and the withdrawal position.

6. Printing device (300) according to any one of claims 1 to 5, characterized in that the blower member (320) is further adapted to be moved to a release position in which it is held at distance from the outlet of the platen press (310).

7. Printing device (300) according to claim 6, characterized in that it comprises second guide means (350) adapted to guide the movement of the blower member (320) in the disengagement position.

8. Printing device (300) according to one of the claims 6 or 7, characterized in that it comprises second motor means (360) adapted to move the blower member (320) in the disengaged position.

9. Printing device (300) according to any one of claims 1 to 8, characterized in that it further comprises a return member (370) capable of guiding each band stamping (410) at the exit of the platen press (310), and in that said return member (370) is mounted movably in displacement between a close position in which it is adapted to operate at least partly in the passage zone in which the bars run. clamps (610) at the outlet of the platen press (310), and a remote position in which it is spaced apart from said passage area.

10. Printing device (300) according to claim 9, characterized in that between the close position and the remote position, the return member (370) is movably mounted in translation along a plane path which is substantially orthogonal to the passage plane in which the sheets (10, 20) circulate inside the platen press.

11. Printing device (300) according to one of claims 9 or 10, characterized in that between the close position and the remote position, the return member (370) is mounted to move in translation in a direction which is generally substantially oblique with respect to the passage plane along which the sheets (10, 20) circulate inside the platen press (310), said oblique direction approaching said platen press (310) as it approaches said passage plane.

12. Printing device (300) according to any one of claims 9 to 11, characterized in that it comprises third guide means (380) adapted to guide the displacement of the return member (370) between the close position and the distant position.

13. Printing device (300) according to any one of claims 9 to 12, characterized in that it comprises third motor means (390) adapted to move the return member (370) between the close position and the distant position.

14. Processing machine (1) of sheet-shaped elements (10, 20), characterized in that it comprises at least one printing device (300) according to any one of the preceding claims.