EP0132858A1 - Perfecting rotary multicolour printing machine - Google Patents

Abstract

The machine can print on both sides of the paper either a color image juxtaposed by means of a letter plate (5a, 15a) respectively inked by a collecting cylinder (6,16) in turn inked by color picking cylinders ( 8.8a; 18.18a), the number of which corresponds to the number of colors, i.e. a color image and drawings superimposed by means of the plate cylinders (8.8b; 18.18b) which replace the selector cylinders and are provided with printing plates inking a respective offset cylinder and the number of which corresponds to the number of colors and designs, ie an image of each type mentioned. For this purpose the machine comprises two blanket cylinders (6,16) which function either as collecting cylinders spaced from one another, each in contact with a cylinder (5; 15) carrying said typographic plate (5a, 15a ) whose image is transferred via another blanket cylinder (4,14) on the paper, either as pressurized offsets and printing on the paper, or one as a collecting cylinder and the other as an offset cylinder , both discarded. In the latter case, the image on the offset cylinder is transmitted via a transmission cylinder which replaces the typographic plate cylinder, to said blanket cylinder.

Description

The invention relates to a multi-color rotary printing machine for duplex printing simultaneously with the reel or the sheet, in particular for printing the security background of fiduciary papers and in particular banknotes, comprising a first pair of blanket cylinders along the periphery of each of these cylinders being arranged a group of several cylinders, each inked by an inking device in a different color and which cooperate with this corresponding blanket cylinder of said first pair for applying a multicolored image thereto, and comprising a second pair of blanket cylinders each cooperating with a roller arranged to be brought into contact with one, respectively the other, of said blanket cylinders of the first pair.

In a published German patent application (DE-A-31 09 964) such a machine has already been described ensuring on each side of the paper the printing of an image with juxtaposed colors. Each image is printed by means of a single typographic printing plate representing the complete drawing to be printed and mounted on one of said rolls. This typographic plate is inked by a collecting cylinder formed by one of said blanket cylinders of the first pair which is in turn inked by a plurality of color picking cylinders which are formed by said group of cylinders and the number of which corresponds the number of colors in an image to print. Each selector cylinder has areas cut in relief representing the parts of the image to be colored in a determined color which its own inking device has transferred to it. This machine is used in particular to print the security background for banknotes.

To carry out the simultaneous printing, the paper passes between the two blanket cylinders of the second pair which are pressed against each other and transfer the image of one respectively from the other inked letterpress plate to one, respectively the other, side of the paper.

By this process which is commonly called "Orlof", a multicolored image is obtained ensuring a perfect register between the different colors of the drawing of the image, a result which is impossible to obtain with any other printing process.

Since the color selector cylinders are in contact with an elastic surface of the collecting cylinder, they can be made of hard material which makes it possible to cut out very fine raised areas, therefore very fine colored parts, for example in the form of lines or dots.

We also know the indirect letterpress printing or offset color and overlapping designs which, too, is often used to print security funds. According to this method, the complete drawing is composed of partial drawings of different colors carried by printing plates mounted on plate-holding cylinders so as to allow the superimposition of drawings and colors in register with each other on a blanket cylinder against which the paper to be printed is pressed. The number of printing plates and, consequently, of plate cylinders corresponds to the number of different colors and designs composing the multicolored image. There are also machines of this type for simultaneous duplex printing in which the paper passes between two blanket cylinders, each receiving a multicolored image of the corresponding plate cylinders.

At the stage of the current technique, machines have each been developed which separately use one or the other of the methods described above.

The purpose of this invention is to create a single machine for simultaneous duplex printing having the possibility of exploiting the two methods described above and called below "Orlof" method and offset process, as well as the two processes for both "Orlof" printing on one side and offset printing on the other side of the paper, ensuring the passage from one process to the other in the simplest way.

To achieve this goal, the machine is characterized by the characteristic clause of claim 1.

The advantage of this machine is not only technical because it allows to operate two completely different processes, as well as the combination of these two processes at the same time, but also economic because it offers the user a choice of process without having to resort to three separate machines. The transformations which must be carried out by machine, passing from one process to another, are very simple.

An advantageous embodiment for sheet printing is described in the dependent claim.

• La figure 1 représente schématiquement pour une machine d'impression à la bobine la position de tous les organes lorsqu'elle imprime le procédé "Orlof"-"Orlof".
• La figure 2 représente schématiquement la même machine disposée pour l'impression offset-offset.
• La figure 3 représente schématiquement la même machine lorsqu'elle imprime selon le procédé Offset-"Orlof".
• La figure 4 représente schématiquement la même machine lorsqu'elle imprime selon le procédé "Orlof"-Offset, les moitiés de la machine étant échangées par rapport à la figure 3.
• La figure 5 représente pour une machine d'impression à la feuille la position de tous les organes lorsqu'elle imprime le procédé "Orlof"-"Orlof".
• La figure 6 représente schématiquement la même machine disposée pour l'impression offset-offset.
• La figure 7 représente schématiquement la même machine lorsqu'elle imprime selon le procédé offset-"Orlof".
• La figure 8 représente schématiquement la même machine lorsqu'elle imprime selon le procédé "Orlof"-offset. les deux moitiés de la machine étant échangées par rapport à la figure 7.

The invention will be described by way of nonlimiting example by two embodiments with reference to the accompanying drawings.

• FIG. 1 schematically represents for a spool printing machine the position of all the members when it prints the "Orlof" - "Orlof" process.
• FIG. 2 schematically represents the same machine arranged for offset-offset printing.
• FIG. 3 schematically represents the same machine when it prints according to the Offset- "Orlof" process.
• FIG. 4 schematically represents the same machine when it prints according to the "Orlof" -Offset process, the halves of the machine being exchanged with respect to FIG. 3.
• FIG. 5 represents for a sheet printing machine the position of all the members when it prints the "Orlof" - "Orlof" process.
• FIG. 6 schematically represents the same machine arranged for offset-offset printing.
• FIG. 7 schematically represents the same machine when it prints according to the offset-"Orlof" process.
• FIG. 8 schematically represents the same machine when it prints according to the "Orlof" -offset method. the two halves of the machine being exchanged with respect to FIG. 7.

The figures differ only as regards the arrangement of certain members, thus identical elements are identified by the same references in all the figures.

The machine shown in Figures 1 to 4 relates to a spool printing machine and comprises input rollers 2 for the paper web 1 and a device 3 for dust removal and removal of static electricity from the paper. The paper 1 can be printed either between the two blanket cylinders 4, 14 according to the "Orlof" - "Orlof" process (Figure 1), according to the offset process - "Orlof" (Figure 3) or according to the "Orlof process "-offset (figure 4), ie between the two large blanket cylinders 6,16 according to the offset-offset process (figure 2). After being printed, the paper is transported by exit rollers 10 out of the machine. The directions of rotation of the cylinders are indicated by the arrows. '

For printing according to the "Orlof" - "Orlof" process, the two blanket cylinders 6,16 are spaced from one another (Figure 1), while the blanket cylinders 4,14 are put in pressure. In practice, this spacing is very simply achieved - as illustrated for the cylinders 6, 16 - by means of an eccentric 7, 17, on which the body of each blanket cylinder 6, 16 is mounted. Such an arrangement with eccentric is well known for adjusting the pressure setting and for separating two cylinders if the machine is not in operation, the assembly being such that by turning the eccentric the axis of the cylinder moves. Therefore, for this spacing, the invention uses means which are already known in existing machines. When the two cylinders are spaced apart, the distance between them is very minimal, only 1 or a few mm, the distance illustrated in Figure 1 being greatly exaggerated.

The machine being composed of two symmetrical halves, below only one half will be described in detail, namely the right half.

The blanket cylinder 6 cooperates in the example illustrated in FIG. 1 with four color selector cylinders 8 having reliefs 8a cut out according to the contour of the areas to be printed in the respective color and which are inked in said color, each at by means of an inking device 9 with double inkwell. These selector cylinders 8 with these reliefs 8a are preferably made of hard material which does not risk being deformed even if the relief is very fine, thus making it possible to obtain a safety background composed of very fine lines. The areas of the four colors are transferred to the blanket cylinder 6 which functions as a collecting cylinder on which they are joined and by which they are transferred to a single plate cylinder 5 carrying a letterpress printing plate 5a in contact with said collecting cylinder; this plate 5a represents the complete drawing to be printed in four colors. The complete image inked in the different colors is in turn transferred to the blanket cylinder 4 of a smaller diameter than the blanket cylinder 6, and which cooperates with the blanket cylinder 14 of the other half. of the machine to apply the printing of the complete image on the corresponding side of the paper.

Simultaneously another image is printed on the other side of the paper by this blanket cylinder 14. This other image is created in a similar manner by the corresponding members of the other half of the machine, namely the four cylinders 18 with reliefs 18a inked by the four inking devices 19, the collecting cylinder formed by the other blanket cylinder 16 and by the plate cylinder 15 in contact with the latter and provided with the letter plate 15a representing the complete drawing of said other image transferred to the blanket cylinder 14. During the simultaneous printing the two blanket cylinders 4 and 14 serve mutually as back pressure cylinders.

In the case of using the same machine for printing according to the offset-offset process (Figure 2), it suffices to replace the selector cylinders of colors 8, 8a and 18, 18a with plate cylinders 8, 8b and 18, 18b equipped with printing plates 8b and 18b, to separate the two blanket cylinders 4, 14 from one another and to further separate the plate cylinders 5 and 15 from the cylinder blankets 6 respectively 16 and put these two blanket cylinders 6, 16 under pressure so that they print on the paper 1. The cylinders 4, 5, 14 and 15 are therefore out of function and are not driven, their system of drive is not coupled to the machine drive device.

The printing plates 8b and 18b are offset plates, in particular typographic plates as used in dry offset, and represent partial drawings which are inked, as in the previous case, by inking devices 9 and 19. These partial drawings in different colors are combined on the blanket cylinder 6 respectively 16 operating here as an offset blanket cylinder, therefore as a collecting cylinder for the partial drawings composing the multicolored image. This gives a simultaneous dry offset printing in four colors on each side when the paper passes between the two blanket cylinders 6, 16.

The adjustment of the spacing between the different cylinders, namely between the blanket cylinders 4 and 14, as well as between the blanket cylinders 6 and 16 and between the plate cylinder 5 respectively 15 and the cylinder blankets 6 respectively 16 as well as the necessary displacements of the other rollers and cylinders in relation to the displaced cylinders, is carried out in a manner known per se, in particular by mounting all the rollers and the cylinders on eccentrics as already mentioned for the blanket cylinders 6 and 16. These spacings have very small distances, of the order of a few mm. The inking devices 9 and 19 are generally mounted on mobile carriages.

The machine also allows an Offset- "Orlof" printing, as shown in figure 3. In this case, the positions of the members correspond to the "Orlof" - "Orlof" process according to figure 1.

In the example considered, the right side of the machine produces the "Orlof" impression by means of the color selector cylinders 8, 8a and the plate cylinder 5 carrying a typographic plate 5a, inked. by the blanket cylinder 6 which functions as a collecting cylinder in turn inked by the selector cylinders 8, 8a.

The left side of the machine produces the offset printing by means of the plate cylinders 18 provided with offset plates 18b which ink the blanket cylinder 16. In this case, the image is transferred from this blanket cylinder 16 to the means of an image transmission cylinder 15 'to the blanket cylinder 14; said transmission cylinder 15 'replaces in this operating mode the plate cylinder 15 (Figure 1) and is formed by a rubber cylinder or blanket holder. In this case of mixed simultaneous printing, the offset image is therefore printed on the paper by the blanket cylinder 14 after having been transmitted via the cylinder 15.

In a fourth operating mode (Figure 4), the two halves of the machine are exchanged, which now allows an "Orlof" -Offset print. It is the left side which prints the "Orlof" image by means of the selector cylinders 18,18a and the plate cylinder 15 carrying the letter plate 15a, and the right side which prints the offset image by means of the door cylinders - offsets plates 8,8b and the image transmission cylinder 5 'which replaces the plate cylinder 5.

This possibility of choosing the sides in the case of mixed simultaneous printing is essential if the paper printed in the machine described passes yet another printing unit so that at least one side of the paper receives a second printing, for example. example an intaglio print as main drawing.

Figures 5 to 8 show the different arrangements of a sheet printing machine to perform simultaneous printing "Orlof" - "Orlof" (Figure 5), offset-offset (Figure 6), offset- "Orlof" ( figure 7) and "Orlof" -offset (figure 8). This machine and its four different arrangements are practically identical with the spool printing machine as shown in Figures 1, 2 _; 3 and 4 with the sole exception of the means of transporting the sheets 21. The trajectory of the sheets 21 is indicated in FIGS. 5 to 8 by a bold line. The sheets 21 to be printed are brought in a known manner by a margin cylinder 22 and two transfer cylinders 23 provided with clamps. Unlike the case of the paper strip 1, the sheets 21 are in each operating mode always in contact with one of the blanket cylinders of the pair 4, 14 and one of the blanket cylinders of the pair 6, 16, in the example considered with the blanket cylinders 4 and 6, which also always function as transfer cylinders and which are provided with grippers. To ensure the transfer of the sheets from cylinder 4 to cylinder 6, an intermediate transfer cylinder 24 is provided, provided with grippers, permanently cooperating with the two blanket cylinders 4 and 6. After being printed, the sheets 21 are transported by a chain clamp system 25 on an output stack or to a machine to complete the printing, for example by intaglio printing.

During the "Orlof" - "Orlof" process (Figure 5), the arrangement corresponds to that shown in Figure 1. The two blanket cylinders 6 and 16 are separated from one another and function as collecting cylinders which are inked by the color selector cylinders 8, 6a and 18, 18a and in turn ink the letter plate 5a, respectively 15a on the plate cylinder 5 respectively 15. The inking devices 9 and 19 are only illustrated diagrammatically by a few rollers and include for example the same elements as shown in FIGS. 1 to 4. The blanket cylinders 4 and 14 are pressurized and print the corresponding image on both sides of the sheets 21.

In the example illustrated, the ratio of the diameters of the cylinders 4, 5, 8, 14, 15, 18 and 24 on the one hand and of the cylinders 6 and 16 on the other hand is 1: 3; the periphery of the cylinders 6 and 16 therefore corresponding to three sheets of paper, and these blanket cylinders 6 and 16 each carry three blankets while the cylinders 4 and 14 carry only one blanket.

The fact that the sheets 21 remain in contact with the region of the blanket cylinder 6 on which is still the ink which was not transferred to the plate cylinder 5 has practically no harmful effect, because the arrangement is such that the areas inked on the cylinder 6, when they are in contact with a sheet 21 carrying the image printed by the cylinder 4, are in register with the colored areas of the printed image.

For this condition of register to be fulfilled, the cylinders concerned must be arranged as follows: the sum of the arc length on the periphery of cylinder 5, considered in the direction of rotation of the cylinders, between the point of contact of the latter with cylinder 6 and with cylinder 4, plus the arc length on the periphery of cylinder 4 between the point of contact from it with cylinder 5 and the point of entry of the paper on cylinder 4, plus the length of the path of the paper between the point where it arrives on cylinder 4 to its point of arrival on the cylinder 6, must be equal to the length of the arc on the periphery of the cylinder 6 between the point of contact of the latter with the cylinders 5 and 24 plus the length of the periphery of the cylinder 5 (which is equal to 1 / 3 of the periphery of this cylinder 6). Under these conditions, a point of the image transferred to the paper by the cylinder 4 and coming from one of the three blankets carried by the cylinder 6 coincides, when the paper arrives on the cylinder 6, with the same place of the image of the following blanket. The arrangement of the cylinders concerned for obtaining this register is known (DE-A 3 109 964).

In addition, since the sheets 21 do not undergo any pressure on the cylinder 6, the possible transfer of the ink from the cylinder 6 onto the sheets is very low.

To perform the offset-offset process (Figure 6), the arrangement corresponds to that shown in Figure 2. The two blanket cylinders 6 and 16 are pressurized and inked by the offset plates 8b and 18b mounted on the door cylinders -plate 8, 8b and 18, 18b. The blanket cylinders 4 and 14 are separated from each other, the plate cylinder 5 is separated blanket cylinders 4 and 6, and the plate cylinder 15 is moved away from the blanket cylinder 16. The plate cylinders 5 and 15 as well as the blanket cylinder 14 are therefore out of function, while the the other blanket cylinder 4 serves as a transfer cylinder for the sheets which are transported via the transfer cylinder 24 on the blanket cylinder 6 to be printed by the two cylinders 6 and 16.

To perform the mixed offset- "Orlof" process (figure 7), the arrangement of the organs corresponds to that shown in figure 5.

In the example considered, the right side of the machine produces the "Orlof" impression by means of the color selector cylinders 8, 8a and the plate cylinder 5 carrying a typographic plate 5a, inked by the blanket cylinder 6 which functions as a collecting cylinder in turn inked by the selector cylinders 8, 8a.

The left side of the machine produces offset printing by means of the plate cylinders 18, provided with offset plates 18b which ink the blanket cylinder 16. In this case, the image is transferred from this blanket cylinder 16 by means of an image transmission cylinder 15 'to the blanket cylinder 14; said transmission cylinder 15 'replaces in this operating mode the plate cylinder 15 (Figure 5) and is formed by a rubber cylinder or blanket holder. In the case of mixed simultaneous printing, the offset image is therefore printed on the paper. by the blanket cylinder 14 after being transmitted via the cylinder 15 '. With regard to the contact between the sheets 21 and the blanket cylinder 6 which transports them to the chain clamp system 25, the same remarks given in relation to FIG. 5 are valid.

In a fourth operating mode (figure 8) which allows an "Orlof" -Offset printing, the two halves of the machine are exchanged and it is the left side which prints the "Orlof" image by means of the selector cylinders 18 , 18a, the image transmission cylinder 15 ′ being replaced by a plate cylinder 15 provided with a typographic plate 15a representing the complete drawing, and it is the right side which prints the offset image by means of the offset plate cylinders 8, 8b, the plate cylinder 5 in the previous example being replaced by an image transmission cylinder 5 '.

In all the examples described, the color selector cylinders 8, 8a and 18, 18a intended for inking the blanket cylinder 6. 16 with a collective function can be replaced by sectioned plates functioning as color selector plates applied to a cylinder. In this case, it is therefore sufficient to change from one printing process to another, to change only the plates on the cylinders 8, 18 in contact with the corresponding blanket cylinder, the bodies of the cylinders themselves not being not changed. Likewise, the body of the plate cylinder 5, respectively 15 can remain mounted when one of these cylinders is transformed into a cylinder of 5 'or 15' image transmission if the letter plate is thin enough and can simply be replaced by a blanket and vice versa.

If necessary, at least one of the printing units comprising a plate cylinder 8 or / and 18 and an inking device 9 or / and 19 on one or / and the other side of the machine can also be a wet offset unit, the respective plate cylinder or cylinders being provided with a wet offset plate.

Furthermore, in the machine described for printing on the reel the direction of transport of the paper and the direction of rotation of the rolls can be reversed without inconvenience, in this case the paper passes from bottom to top and it is only the device 3 dedusting and elimination of static electricity which must be installed at the entrance of the machine, therefore at the bottom.

Claims (2)

1. Multicolor rotary printing machine for simultaneous duplex printing on a reel or a sheet, in particular for printing the security background of fiduciary papers and in particular banknotes, comprising a first pair of cylinders blanket holders (6,16), along the periphery of each of these cylinders being arranged a group of several cylinders (8,18), each inked by an inking device (9,19) in a different color and which cooperate with this corresponding blanket cylinder (6,16) of said first pair to apply on it a multicolored image, and comprising a second pair of blanket cylinders (4,14) each cooperating with a roller (5 , 15) arranged to be brought into contact with one, respectively the other, of said blanket cylinders (6,16) of the first pair, characterized in that the path of the paper to be printed passes between the two cylinders - blankets (4,14) of said second pair e and between the two blanket cylinders (6,16) of said first pair and that said machine allows different types of printing by the following arrangements of adjustable or replaceable elements: a) said cylinders of each group are color selector cylinders (8,8a; 18,18a) whose raised areas correspond to the parts of the image to be colored in the various colors and whose number corresponds to the number of colors to be to print; - the two blanket cylinders (6.16) of said first pair are spaced from one another and function as color collecting cylinders; - Said rollers (5,15) are plate cylinders each carrying a typographic plate (5a, 15a) representing the complete drawing to be printed and brought into contact with the corresponding collecting cylinder to be inked by the latter; - the blanket cylinders (4,14) of said second pair are pressurized so that an image in juxtaposed color is printed on each side of the paper by means of the corresponding typographic plate (5a, 15a) inked by the cylinder corresponding collector; b) said cylinders in each group are plate cylinders (8,8b; 18,18b) each equipped with a printing plate, the number of these printing plates for each group corresponds to the number of colors and designs to be printed; - the blanket cylinders (4,14) of said second pair are spaced from each other, themselves and said rollers (5,15) spaced from the corresponding blanket cylinder (6,16) of the first pair having no printing function; - the two blanket cylinders (6.16) of said first pair are pressurized to that a color image and superimposed designs be printed on each side of the paper by means of the plurality of said printing plates (8b, 18b); c) said cylinders of one of said group are color selector cylinders (8,8a or 18,18a) whose raised areas correspond to the parts of the image to be colored in the various colors and whose number corresponds to the number of colors to be printed, while the cylinders of the other group are plate cylinders (18, '18b or 8,8b) each equipped with a printing plate, the number of these printing plates corresponds to number of colors and designs to be printed; - the two blanket cylinders (6,16) of said first pair are spaced from one another and the one (6 or 16) which is in contact with the color selector cylinders functions as a collecting cylinder; - that of said rollers (5 or 15) which is associated with the collecting cylinder carries a typographic plate (5a or 15a) representing the complete drawing to be printed and brought into contact with said collecting cylinder to be inked by the latter, the other of said rollers is an image transmission cylinder (15 'or 5') in contact with the other blanket cylinder (16 or 6) of the first pair; - the blanket cylinders (4,14) of said second pair are pressurized so that a juxtaposed color image is printed on one side of the paper by means of the letterpress plate (5a or 15a) inked by the corresponding collecting cylinder and so that a color image and superimposed designs are printed on the other side of the paper by means of the plurality of said printing plates (8b, 18b) and via said image transmission cylinder (15 'or 5'). 2. Machine according to claim 1, characterized in that for a sheet printing machine there is provided between one of the blanket cylinders (4) of said second pair and the blanket cylinder (6) , located on the same side of the machine, of said first pair, a transfer cylinder (24), said three cylinders (4,24,6) which cooperate together in all operating modes, functioning as transfer cylinders sheets (21), the arrangement being such that in the case where said blanket cylinder (4) of the second pair transfers the image to the sheets, there is a register between this image inked on a sheet and the multicolored image present on said blanket cylinder (6) of the first pair when it comes into contact with this sheet.

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