EP2694280A2

EP2694280A2 - Hot-stamping printing device

Info

Publication number: EP2694280A2
Application number: EP12714224.8A
Authority: EP
Inventors: Julien CHRETIEN
Original assignee: Bobst Mex SA
Current assignee: Bobst Mex SA
Priority date: 2011-04-05
Filing date: 2012-04-05
Publication date: 2014-02-12
Anticipated expiration: 2032-04-05
Also published as: JP5890002B2; JP2014516319A; CN103459135A; EP2694280B1; US9579914B2; CN103459135B; TW201302449A; ES2768241T3; WO2012136373A3; WO2012136373A2; KR101545427B1; US20160325574A1; KR20130133070A; TWI474920B; US20140020575A1; US9849706B2; BR112013025515A2; WO2012136373A9

Abstract

The present invention relates to a device (300) for printing a series of elements in the form of sheets, including a platen press (310) capable of depositing, onto each sheet and by stamping between a static platen (320) and a movable platen (330), a colored or metalized film from at least one strip to be stamped (411), as well as a heating member (340) capable of raising any stamping tool secured to the static platen (320) to a given temperature in order for the stamping operation to be carried out under hot conditions within the platen press (310). The invention is characterized in that the heating member (340) is mounted so as to be movable between an operating position, in which the heating member is inserted between the static platen (320) and each stamping tool associated with said static platen (320), and a maintenance position, in which the heating member is positioned outside the platen press 310.

Description

HOT STAMP PRINTING DEVICE

The present invention relates to a device for printing a succession of sheet-shaped elements by hot 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 traditionally. performed by means of a vertical platen press, in which each printing medium and the stamping strips involved are pressed together between two parallel plates, one of which is static while the other is movably mounted in following motion a vertical back and forth motion.

In the case of hot stamping, film transfer requires heat input in addition to pressurization. For this reason, a heating element is usually interposed between the static plate and the stamping tools that are associated with the latter. Such a heating member is generally in the form of a heating plate, one side is covered with an insulator intended to interface with the plate, while the other side is intended to extend to the back of stamping tools.

In practice, the heating element is secured to the static plate by means of several fixing screws that come up from the inside of the platen press. This concretely means that each of them passes through the heating element before coming to screw in a tapped fit in the plate.

This type of arrangement, however, has the disadvantage of providing particularly difficult access to the heater, which has the effect of significantly complicating maintenance or troubleshooting. The mounting or dismounting of the fastening screws requires in fact to pass the arms between the plates of the press, which proves extremely impractical. In addition, to reach the fixing screws furthest away from the driver's side, it is often essential to remove some peripherals implanted directly upstream and downstream of the platen press. Finally, it is necessary to manually support the heating member during the entire phase of extraction or insertion in the platen press.

Also, the technical problem to be solved by the object of the present invention is to propose a device for printing a succession of sheet-shaped elements, comprising a platen press capable of depositing on each sheet, by stamping between a static plate and a movable platen, colored or metallized film from at least one stamping strip, and a heating element able to bring to a given temperature any stamping tool integral with the platen static so that the embossing operation takes place hot within the platen press, printing device that would avoid the problems of the state of the in particular by providing substantially easier maintenance.

The solution to the technical problem posed consists, according to the present invention, in that the heating element is movably mounted in displacement between an operating position in which it is interposed between the static plate and each stamping tool associated with said plate. and a maintenance position in which it is disposed out of the platen press.

It is worth emphasizing that at this stage of the description, the mobility of the heating element can in theory operate according to any movement. In the same way, its trajectory of displacement can be any, that is to say to be purely rectilinear or circular, to be more generally curvilinear, or to result from any combination of these movements.

The important thing is that the operating position is one in which the heating element is fully operational, that is to say able to fulfill its heating function within the platen press. In the maintenance position, however, it is essential that the heating element be held outside the platen press, in a place sufficiently accessible so that it can be operated directly on it or easily taken to a location. even more adequate.

Whatever the case may be, the invention as thus defined has the advantage of requiring no intervention at the heart of the platen press, both for extracting and for setting up the heating element. Unlike its counterparts of the prior art, the heating element according to the invention is not simply removable mounted, that is to say fixed reversibly. It is also movably mounted on the move, which means that it is mechanically supported and guided during any transfer between the inside and the outside of the platen press. Any intervention on the heater, for example to test its heating capacity independently of the rest of the machine, so can be done with ease, speed and comfort.

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 consists of and how it can be achieved. The description is further given with reference to the accompanying drawings in which:

FIG. 1 represents a processing machine which is intended to print sheets of cardboard by hot stamping, and which is equipped for this purpose with a printing device according to the invention.

FIG. 2 is a perspective view which more specifically details the printing device visible in FIG.

Figures 3 to 7 illustrate the movement kinematics of the heating member relative to the platen press, during a transfer from the inside to the outside of said press.

Figure 3 shows the heater in operating position within the platen press. FIG. 4 represents the heating element at the moment of its unlocking, at the beginning of the transfer phase.

Figure 5 shows the heater in an intermediate position of the transfer.

Figure 6 relates to the end of the transfer, that is to say the moment when the heater reaches its maintenance position.

Figure 7 illustrates the removal of the heater from the maintenance position.

Figure 8 is a vertical cross section at the static plate of the press, which reveals the attachment of the heater in the operating position.

Figures 9 and 10 are views similar to Figures 3 and 7, but which correspond to an alternative embodiment whose particularity is to associate an electrical connection box to the heating member.

For the sake of clarity, the same elements have been designated by identical references. Similarly, only the essential elements for the understanding of the invention have been represented, and this without respect of the scale and schematically.

Figure 1 illustrates a processing machine 1 for customizing cardboard packaging for the luxury industry. Commonly referred to as a gilding machine, this processing machine 1 is conventionally composed of several work stations 100, 200, 300, 400, 500 which are juxtaposed but interdependent one by one in order to form a unitary unit able to process a succession of supports sheet-shaped printing. There is thus a feeder 100, a margin table 200, a device 300, a tape feed and recovery station 400, and a receiving station 500. Transport means 600 are further provided for individually moving each sheet from the output of the margin table 200 to at the receiving station 500, including through the printing device 300.

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

In this particular embodiment, selected solely by way of example, the feeder 100 is supplied with cardboard sheets from a succession of stacks stored on pallets. The leaves are successively removed from the top of each stack by a suction gripper which transports them to the directly adjacent margin table 200.

At the level of the margin table 200, the sheets are tabled by the suction grip member, 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 conveyor mechanism. At the end of the web, the head sheet is systematically accurately positioned by means of front and side cleats.

The workstation located immediately after the margin table 200 is therefore the printing device 300. This station has the function of depositing on each sheet, by hot stamping, the film metallized which is from a single tape stamp 410 in this embodiment. It uses for this purpose a platen press 310 in which the stamping operation is carried out between an upper platen 320 which is static, and a lower platen 330 which is mounted movably in movement in a movement of va-et- comes vertical. Embossing tools (not shown) are of course associated with each of the plates 320, 330.

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 exemplary embodiment, the strip 410 is conventionally stored in a wound form, around a supply reel 420 rotatably mounted. 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 path scrolling to drive said strip 410 on the move. A guide 444 is also present just downstream of the platen press 310.

The process of processing the sheets ends in the receiving station 500 whose main function is to repackage the previously treated sheets. For this, the transport means 600 are arranged to automatically release each sheet when the latter is found at the right of the new stack. The sheet then falls squarely on the top of the stack.

In a very conventional manner, the transport means 600 implement a series of gripper bars 610 which are movably mounted in transverse translation via two chain trains 620 arranged laterally on each side of the processing machine 1. chain train 620 traverses a loop which 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.

As can be seen more specifically in FIG. 2, the printing device 300 is designed to be able to generate hot stamping. To do this, the platen press 310 is equipped with a heater 340 which is capable of carrying at a given temperature, each stamping tool (not shown) which is associated with the static plate 320.

In accordance with the object of the present invention, this heating member 340 is mounted movably in displacement between an operating position and a maintenance position. The assembly is arranged so that in the operating position, the heating member 340 is interposed between the plate static 320 and each stamping tool associated with said plate 320 (Figures 2 to 4), and that in the maintenance position, said heater member 340 is disposed outside the platen press 310 (Figure 6 ).

According to a feature of the invention, the printing device 300 is provided with means 350 for transporting the heater member 340 between the operating position and the maintenance position. This characteristic implies in practice that the transport means 350 are capable of providing real support and guidance functions during the transfer of the heating element 340.

Particularly advantageously, the printing device 300 is arranged in such a way that the displacement of the heating element 340 takes place in two stages. Thus, the transport means 350 are first of all able to translate the heating member 340 in a direction substantially orthogonal to the inner face 321 of the static plate 320. This mobility is exerted between the position of operation (Figures 3 and 4) and an intermediate position in which the heater 340 is disposed between the two plates 320, 330 of the press 310 but at a distance therefrom (Figure 5). However, on the other hand, the transport means 350 are also able to translate the heating element 340 in a direction substantially parallel to the internal face 321 of the static plate 320. The mobility then takes place between the intermediate position previously defined ( Figure 5) and the maintenance position (Figure 6).

In the embodiment chosen to illustrate the invention, the printing device 300 is conventionally equipped with a frame 351 responsible for supporting each stamping tool associated with the static plate 320. Similarly conventional, this frame 351 is mounted movably in displacement between a position of use (FIGS. 3 and 4). ) in which it extends facing and in contact with the heating member 340 in the operating position, and an extraction position in which it is disposed outside the platen press 310 (FIGS. 6 and 7). ).

Under these conditions and in accordance with a presently preferred embodiment of the invention, the frame 351, forming means of transport 350, is able to transport the heating member 340 between the operating position and the maintenance position when said frame 351 is moved between the use position and the extraction position. The advantage of such an embodiment is to avoid the design and implementation of a specific system to transfer the heater 340, using a pre-existing transport system, in this case the mobile frame 351 which is responsible for supporting the stamping tools associated with the static plate 320.

In practice, the transfer between the inside and the outside of the platen press 310, of the moving assembly constituted by the heating member 340 placed on the frame 351, is carried out transversely by passing through a lateral opening 312 formed through the portion of the frame 311 which is located on the driver's side.

The displacement of the moving assembly 340, 351 from the inside to the outside of the platen press 310 thus starts with a vertical descent of the frame 351 between the plates 320, 330 of the press 310. Concretely, this operation is carried out by means of four locking hooks 352 which are substantially located at the four corners of the frame 351, and which are mounted simultaneously movable in vertical translation so as to be able to transport said frame 351 horizontally. the mobility of each hook 352 is exerted between a high position in which it comes to press the frame 351 against the heating member 340 which is itself in contact with the static plate 320 (Figures 3 and 4), and a position base in which it is spaced apart from the frame 351 after having laid it in abutment on two sets of transfer rollers 353a, 353b (FIGS. 5 to 7). The assembly is arranged so that when the chassis 351 actually rests on these rollers 353a, 353b, the heater member 340 is in the intermediate position.

Between their high position and their low position, the synchronized translation of the four hooks 352 results from the combined action of individual elastic return means (not shown) and common unidirectional displacement means (not shown). In this embodiment, each hook 352 is in fact coupled to a stack of spring washers, forming resilient return means, which permanently drives it to the high position. But it is also coupled to a pneumatic system, forming unidirectional displacement means, which is able to drive on command in the low position, despite the permanent action of the elastic return means.

Once the intermediate position is reached by the heating element 340, the movement of the moving assembly 340, 351 from the inside to the outside of the platen press 310 continues with a translation horizontally through the lateral opening 312. In practice, this operation is performed by sliding the frame 351 through the use of several sets of rotary rollers 353a, 353b, 354a, 354b which are implanted both inside outside the platen press 310.

Specifically, the sliding inside the platen press 310 is performed on two sets of internal rollers 353a, 353b which are mounted on the frame 311, and which are positioned vis-a-vis respectively upstream and downstream. of said press 310. With regard to the sliding of the frame 351 outside the press 310, two sets of outer rollers 354a, 354b are used. ^'They are positioned in the respective extensions of the two internal sets of rollers 353a, 353b, at two arm supports 312a, 312b located on either side of the side opening 312. The assembly is arranged so that that the horizontal translation of the frame 351 corresponds to the transfer of the heating member 340 between the intermediate position and the maintenance position.

It is worth noting that contrary to the vertical translation previously described, the horizontal translation of the chassis is not mechanized. It is operated manually by means of two movement handles 355.

According to another feature of the invention, the printing device 300 is further provided with fixing means 360 for immobilizing the heating member 340 in the operating position. Of course, such immobilization must be reversible in order to preserve the displacement capacity of the heating element 340. This means that the fastening means 360 must be deactivated prior to the extraction of the heating element 340, and activated before any switching on of the printing device 300

Particularly advantageously, the fixing means 360 are designed to press the heating member 340 against the inner face 321 of the static plate 320, by pulling it from a portion of said static plate 320, which is situated substantially at the opposite of said inner face 321. Regardless of the immobilization it generates, the advantage of such a plating is to avoid buckling of the heating member 340 under the effect of heat, but also to limit the vibrations resulting from the back and forth movements of the movable stage 330.

According to another advantageous characteristic, the fastening means 360 are accessible from the face of the static plate 320, said external face 322, which is opposite to the internal face 321. It should be noted that this notion of accessibility also concerns the setting up of the fixing means 360, that their activation or deactivation.

In this embodiment, the fastening means 360 comprise a plurality of tie rods 361 which take place in as many positioning holes 323 (FIG. 2) formed through the static plate 320 in a direction substantially orthogonal to the internal face 321. elsewhere, each tie 361 comprises a stop-shaped head 362 which bears against a portion of the static plate 320 which is substantially opposite to the inner face 321, and a threaded end 363 which is screwed into a tapping 341 formed in the heating member 340.

As can be seen clearly in Figure 8, each tie 361 is concretely in the form of a threaded rod which passes vertically through the static plate 320 from one side to the other. Its head 362 is positioned at the outer face 322 of the static plate 320, which makes it directly accessible from the outside of the press 310. Its threaded end 363 exceeds that of the static plate 320 in order to come screw into the heating member 340 placed just below.

In this embodiment, the heating member 340 has a composite structure which associates a heating plate 343 and an insulating plate 344 positioned one below the other. The outer face of the heating plate 343 is turned towards the inside of the platen press 310, that is to say, facing the stamping tools, while the external face of the insulator 344 is pressed against the static plate 320.

According to FIG. 8, the heating plate 343 also has a composite structure, insofar as it consists of a heat-conducting plate 345 in which a plurality of heating elements 346 are integrated. For this purpose, housing 347 is formed in the thickness of the heat-conducting plate 345, and they are sized to receive heating elements 346 of the electric resistance type.

The supply wires of the various heating bodies 346 extend along the upstream and downstream edges of the heat-conducting plate 345, before being grouped together to connect to one and the same housing. connection 348 (FIGS. 9 and 10) which is implanted laterally, on the side where the operator of the machine 1 operates. In a particularly advantageous manner, this connection box 348 is integral with the heater member 340.

In this logic, and according to another advantageous characteristic, the printing device 300 also has fastening means for securing the connection box 348 to the frame 311 of the platen press 310. In practice, the use of Such fastening means is not only intended to maintain the connection box 348, since it also makes it possible to pre-position the heating member 340 with respect to the static plate 320 before they are secured by the tie rods 361. this example, the fastening means are constituted by screws which are screwed directly into the frame (not shown in Figures 9 and 10 but visible in Figure 2) of the platen press 310.

It should be noted that even if it appears theoretically possible to use only one tie 361 to perform the immobilization function, it will preferably be used several distributed over the entire surface of the heating member 340, in accordance with the embodiment of Figures 1 to 10. In this regard, it is also observed that this distribution is here not regular. This is due both to the fact that the positioning of each tie 361 takes into account the location of the various heating bodies 346 that make up the heating member 340, that the tie rods 361 must be more numerous in the central zone of the heater 340, since it is here that the constraints are the most important. As can be seen distinctly on the section of Figure 8, each positioning hole 323 has a section substantially greater than that of tie rod 361 associated therewith. This feature is intended to create a radial clearance between the tie rod 361 and the static plate 320, so as to allow free thermal expansion of the heater member 340.

In a particularly advantageous manner, each tie 361 comprises an elastically deformable element 364 which is interposed axially between the head 362 and the static platen portion 320 which serves as a support surface for said tie rod 361. This characteristic is intended to compensate the pressure forces that are generated in the platen press 310, as well as the thermal expansion experienced by the heater 340 in the direction of the tie rods 361.

In this embodiment, each elastically deformable element 364 is constituted by a stack of conical washers 365 which are positioned head-to-tail so as to form a compact spring of great stiffness.

Of course, the invention more generally relates to any processing machine 1 of a succession of sheet-shaped elements, which comprises at least one printing device 300 as previously described. Such a processing machine 1 can be a simple gilding machine as in the embodiment chosen to illustrate the invention, but it can also integrate other functions such as cutting, the separation of poses, the ejection of waste, etc.

Claims

A printing device (300) for a succession of sheet-like elements, comprising a platen press (310) capable of depositing on each sheet, by stamping between a static platen (320) and a movable platen (330), colored or metallized film from at least one stamping strip (410), and a heating member (340) able to bring to a given temperature any stamping tool integral with the platen static (320) so that the embossing operation is carried out hot in the platen press (310), characterized in that the heating member (340) is mounted movably in displacement between an operating position in which is interposed between the static plate (320) and each stamping tool associated with said plate (320), and a maintenance position in which it is disposed outside the platen press (310).

2. Printing device (300) according to claim 1, characterized in that it comprises means (350) adapted to transport the heating member (340) between the operating position and the maintenance position.

3. Printing device (300) according to claim 2, characterized in that the transport means (350) are able to translate the heating member (340), on the one hand, in a direction substantially orthogonal to the internal face (321) of the static plate (320), between the operating position and an intermediate position in which said heating member (340) is disposed between the two plates (320, 330) of the press (310) but at a distance from the latter, and secondly, in a direction substantially parallel to the internal face (321) of the static board (320) between said intermediate position and the maintenance position.

The printing device (300) according to one of claims 2 or 3, further comprising a frame

(351) which is responsible for supporting each stamping tool associated with the static plate (320), and which is mounted movably in displacement between a position of use in which it extends facing and in contact with the body heater (340) in operating position, and an extraction position in which it is disposed outside the platen press (310), characterized in that the frame (351), forming a transport means (350) ), is able to transport the heater (340) between the operating position and the maintenance position when said frame (351) is moved between the use position and the extraction position.

5. Printing device (300) according to any one of claims 1 to 4, characterized in that it comprises fixing means (360) adapted to immobilize the heating member (340) in the operating position.

6. Printing device (300) according to claim 5, characterized in that the fixing means (360) are able to press the organ of heating (340) against the inner face (321) of the static platen (320), by pulling it from a portion of said static platen (320), which is situated substantially opposite said inner face (321).

7. Printing device (300) according to one of claims 5 or 6, characterized in that the fastening means (360) are accessible from the face of the static plate (320), said outer face (322), which is opposed to the inner face (321).

The printing device (300) according to any one of claims 5 to 7, characterized in that; that the fastening means (360) comprise at least one tie rod (361) which takes place in a positioning hole (323) formed through the static plate (320) in a direction substantially orthogonal to the internal face (321), and which comprises a stop-shaped head (362) bearing against a portion of the static plate (320) which is substantially opposite to the inner face (321), and a threaded end (363) screwed into a tapping (341) formed in the heater (340).

9. Printing device (300) according to claim 8, characterized in that each positioning hole (323) has a section substantially greater than that of said tie rod (361) associated therewith.

10. Printing device (300) according to one of claims 8 or 9, characterized in that each tie rod (361) comprises an elastic member. deformable (364) which is interposed axially between the head (362) and the static platinum portion (320) which serves as a bearing surface to said tie rod (361).

11. Printing device (300) according to claim 10, characterized in that each elastically deformable element (364) is constituted by a stack of conical washers (365) positioned head to tail.

12. Printing device (300) according to any one of claims 1 to 11, characterized in that the heating member (340) incorporates a plurality of heating bodies (346) which are electrically connected to at least one connection box (348), and in that each connection box (348) is integral with the heating member (340).

13. Printing device (300) according to claim 12, characterized in that it comprises fixing means adapted to secure each connection box (348) to the platen press (310).

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