EP0305235A1 - Removable printing unit for offset-printing presses - Google Patents

Abstract

A detachable printing unit for offset printing presses, which can be incorporated during their manufacture or fitted to existing presses, said unit being defined in that it is composed of an independent inking module 16 (FIG. 3) comprising all the components required for effecting in chronological operating order the moistening and inking of an offset plate ready for printing on a blanket, and a likewise independent detachable blanket cylinder 7C. One embodiment of the invention is defined in that the numbering device with which the press is equipped (FIG. 6, View B) is replaced by the blanket cylinder (FIG. 7, View B) of the printing unit working with the inking module 16 (FIG. 3), and use is made of the drive mechanism 8 (FIG. 6) and pressure adjustment mechanism 9B provided in the press to obtain for each printing cycle, instead of the numbering, an additional color obtained by color superimposition with the aid of the pressure cylinder 4. In the other form of the invention the same inking module, disposed in another position in the press, works conjointly with the blanket cylinder 3 of the press to enable for each printing cycle an additional color and optionally letterpress numbering or an additional letterpress color to be achieved.

Description

The present invention relates to a removable printing unit, adaptable to existing offset printing presses or incorporable during their manufacture.

This printing unit consists of an inking module and a blanket cylinder, independent of each other, so as to allow the inking module to be used alone or in conjunction with the cylinder blanket holder.

In one of its forms, the invention is characterized by the fact of replacing the numbering device fitted to the press with the blanket cylinder of the printing unit working with the inking module, of using the drive mechanisms and for adjusting the pressure delivered by the press, in order to obtain, by printing cycle, instead of numbering, a complementary color produced by superimposing colors.

In the other form of the invention, the same inking module placed at another location on the press, works jointly with the blanket cylinder thereof, to allow, by printing cycle, to obtain a additional color and possibly numbering.

Currently the vast majority of professional offset printing presses are designed to carry out tri- or four-color printing. Their mode of operation varies little from one manufacturer to another and the choice of printer is oriented by the reliability of the equipment, its simplicity of start-up, driving and its production possibilities.

As an indication, a schematic description is given, with reference to the appended drawings, of the principle of operation of a traditional GTO Heidelberg press representative of this type of machine and therefore retained to illustrate the invention.

The press Figure 1 consists of a frame 1 comprising all of the components. The inking group 2A and its wetting device 2B (inking rollers shown in full and those of halftone wetting) moistens and inks the offset plate fixed on the plate cylinder 2. The inked plate prints its pattern on the blanket of the blanket cylinder 3. The paper 5, coming from the stack 5A, is printed by transfer passing between the blanket 3 and pressure 4 cylinders. The printed sheet is taken up by the pliers of the chain output device 6, to be deposited on the receiving stack 5B. The 2C inkwell as well as the wetting system starting from the 2D water reserve are provided with means making it possible to adjust the ink and water supply, according to the ink charge necessary for the type of printing to be produced. . The plate cylinder 2 has the means for hooking and planing the offset plate and adjustment possibilities for moving it circumferentially relative to the blanket cylinder 3, so as to allow the correct positioning of the printing on the support to be to print. The blanket cylinder 3 also includes the mechanical elements necessary for fixing and tensioning the blanket. The back pressure cylinder 4 is provided with pliers to hold the sheet during printing.

A removable, typographic 7 Figure 2 numbering and color-matching device equips these presses and operates as follows:

The inking group 7A inks the numberers 9B or the printing blocks which deposit their printing directly on the sheet 5 having just received its offset printing of the blanket of the blanket cylinder 3. This typographic printing is carried out online, in the same cycle that offset printing and perfectly locating with it, the drive members being synchronized and interconnected. The pressure necessary for this letterpress printing is obtained between the backpressure cylinder 4 (as in offset printing) and the numberers or plates. The adjustment screws 7B, placed on each side of the press, allow micrometric adjustment of the pressure of the shaft carrying the numberers or plates. The chronological order determined to carry out the various maneuvers leading to printing is ordered by different control levers designed to execute this order. All of these functions are synchronized by print cycle. These presses are equipped with a very precise positioning mechanism for the sheet, allowing them, in the case of successive prints of the same print, to obtain perfect registration between each color. This type of professional press is also produced in 2, 4 and 5 colors. These multicolored presses are made up of several basic color presses. The sheet passes successively from one press to another, by mechanisms conveying it positively using pliers. On these presses, the numbering device is positioned on the end of printing press. Some manufacturers offer, as an option, an additional inking group of an offset color, most often removable. These groups are independent, and include all the elements suitable for wetting and inking an offset plate fixed on a plate cylinder of the same diameter as that of the basic press, as well as the control mechanisms suitable for chronologically ordering all the functions. . This inked plate prints its image on the blanket of the press, which therefore receives two inked images of different colors per printing cycle. These two images are transferred simultaneously to the sheet passing between the blanket and press pressure cylinders. Most often, these booster groups are not manufactured by the major manufacturers of printing presses. An American manufacturer has specialized in this type of printing units adaptable to all kinds of presses and many American and foreign printers use them with success because these auxiliary groups render great services to the printers, but do not allow however, to obtain, in a positive manner, prints in raster overlay, without risk of pollution by mixing the inks together and this in a printing time period more or less long depending on the importance of the superimposed patterns to be inked .

This serious restriction due to the principle of this support group, to a large extent limits its use and does not allow the printer. I consider its press equipped with this adaptation to be a real two-color press.

The evolution of graphics, tastes and printing techniques make the need to print multicolored prints inexpensive. Nowadays, for a good number of printers not specialized in color printing, the purchase of a two-color press is problematic, since its cost and size are appreciably doubled compared to a one-color press, making its amortization difficult. This factor is all the more sensitive for quality presses of relatively small format, such as GTO., Which can hardly compete, for large print runs in four-color printing, double or quadruple format presses. Furthermore, a two-color press is ill-suited to one-color printing.

The present invention aims to improve the state of the art, by enabling the production of compact offset presses, offering the printer increased possibilities.

• a) un module d'encrage amovible d'un type traditionnel et connu, dont la puissance d'encrage correspond le plus généralement à celle de la presse, possédant son propre groupe de mouillage, d'encrage et cylindre porte plaque ainsi que l'ensemble des mécanismes permettant, par ordre chronologique, d'effectuer l'encrage de la plaque offset.
• b) un cylindre porte blanchet amovible, monté sur l'arbre du dispo­sitif de numérotation ou couleur d'appoint typographique de la presse et la remplaçant.

In the context of the invention, the additional means provided to a traditional offset printing press are generally defined as follows:

• a) a removable inking module of a traditional and known type, the inking power of which generally corresponds to that of the press, having its own wetting group, inking and plate cylinder as well as the set of mechanisms allowing, in chronological order, to carry out the inking of the offset plate.
• b) a removable blanket cylinder, mounted on the shaft of the numbering device or typographical makeup color of the press and replacing it.

From these two elements of the printing unit and according to their location on the press, the printer can, at will and in a short time, transform his one color press either into a real two-color press offering the same possibilities and performances that a two-color press constructed from two presses be a one-color press plus a fill color and numbering group.

A third possibility is offered on these presses comprising the adaptation members of these different elements, to mount on the press transformed into true two colors a complementary booster group.

In the case where the press to be equipped with an additional printing unit is not provided with a numbering device, this can be installed and its drive shaft will be used in the same way as on a press equipped with the origin to support and drive the blanket cylinder.

Apart from adaptations to existing presses and without departing from the scope of the present invention, the production of presses comprising directly during their construction the same removable and modular elements is desirable, because it allows machines to be obtained at lower cost. of two colors, indifferently producing one or two colors or twice two colors, much more compact and easy to use and offering significant additional possibilities. It is obvious that the printing unit can include wide variants in these inking or wetting modes or print in "waterless" offset printing without departing from the scope of the invention.

These various possibilities are very interesting for the printer because, in the case of printing in superposition of colors, the numbering is seldom necessary, on the other hand, the jobs in numbering often require an additional color.

Figure 3 shows the printing unit where the removable inking module 16 works with its blanket cylinder 7C to obtain a complementary color superimposed on that of the press. This blanket cylinder 7C is mounted directly on the same axis 9 which carries the rings 9A Figure 2 numberers door 9B. The drive is provided by the gear 8. Figure 9 used to rotate the typographic inking group 7A Figure 2 and additional printing used for numbering. The plate cylinder 17 Figure 3 includes all the usual plate tensioning and planing devices as well as a circumferential and axial adjustment allowing the correct positioning of the print in the print. The wetting group 18 transfers the wetting liquid from its reserve 19 to the plate cylinder 17 by virtue of the conventional water ducting assembly 20, taker 21, portable table 22, wetting roller 23 and wetting touch rollers 24. The ink contained in the inkwell 25 is conveyed and milled to the touch rollers 24A inking the offset plate using the pick rollers 26 distributors 23A and grinding cylinder 22A. The sheet of paper 5 taken from the stack 5A is successively pressed by the pressure cylinder 4 a first time against the blanket cylinder 3 normally installed on the press and which prints the first color, then a second time against the blanket cylinder 7C which prints the second color. The sheet 5 having received the two colors of ink is taken up by the pliers of the chain conveyor 6 and deposited on the receiving stack 5B.

The inking module 16 is supported by two bearings 27 whose removable caps 28 Figure 5 keep the axes of rotation in position 29A Figure 9 thus allowing the inking module 16 to follow the weak movements of pressurization of the axis 9 Figure 3 of the extra blanket cylinder 7C when the press is printing and depressurized when it is stopped. The possibility of rapidly dismantling the caps 28 Figure 5 of the bearings 27 makes it possible to move very quickly from the configuration Figure 3 using the extra blanket holder 7C fixed on the shaft 9 numbering holders, to the configuration Figure 7 where the cylinder carries plate 17 of the inking module 16 deposits the second color of ink on the blanket of the blanket cylinder 3; the first ink color has already been applied to it by the plate cylinder 2 of the press. In this configuration, the typographic numbering and color system is normally used.

Figure 5 shows the inking module 16 in the stored position, out of service.

For greater ease and greater precision in the movements and positioning of the inking module 16, assistance handling, whose mechanism is retracted during printing, was obtained in the following manner: the pneumatic springs 29 bear on the frame 1 of the press and the lifting arms 30 articulated on the bearings 31 fixed on the frame 1 of the press, raise the inking head 16 by means of the connecting rods 32 articulated on the arms 30 by the axes 33 and on the inking head 16 by the axes 34. The eccentric axis 31A maneuvered by the lever 31B allows, at rest, to deposit the device on the top of the frame of the printing press.

The invention as characterized in its claims is described below in detail using the drawings appended to the text representing one of the preferred embodiments in its various printing versions, adapted on a GTO Heidelberg press.

Figure 6 view A shows in front view, press reception side, the blanket cylinder 3 on which is fixed and adjusted the toothed wheel 3A for driving the inking module 16 Figure 3 in the printing position two colors superimposed . The gear 8 Figure 6 acts as a power take-off driving the rotary shaft 9 serving as a rotary support either for the discs 9A Figure 6 view B on which the numberers 9B are fixed, or to the sleeve 9C Figure 7 view A on which are bonded the printing blocks or either for carrying out the invention with the blanket cylinder 7C Figure 7 view B and on which the plate cylinder 17 Figure 3 of the inking module 16 will deposit the ink from its plate representing the image to reproduce. The micrometric screws 7B Figure 2 for adjusting the pressure provided for letterpress printing, retain their same function in offset printing. The bearings 27 and 27A and their flanges 28 and 28A allow, in the two operating positions of the inking module 16 Figure 3, to support it and position it on the press. The ring 8A Figure 6 view A positions and serves as a bearing for the bearing 9D Figure 8 view A of the movable support shaft 9 Figure 6 view B. The device for automatically disengaging the pressure in the event that the sheet is not fed two-color offset printing.

Figure 6 view B shows the same section of the press as view A and also shows the rotary support shaft 9 connected to the power take-off gear 8 and the ring 8A serving to support it, rotating in phase with the machine and on which the disks 9A and the numberers 9B were installed, before assembly.

FIG. 7 view A shows, for a good understanding of the invention, the same section where the disks 9A FIG. 6 view B provided with the numberers 9B are replaced by the sleeve 9C FIG. 7 view A, on which the typographical plates are fixed, mounted on the same rotary support shaft 9.

Figure 7 view B shows the same section, where the sleeve 9C Figure 7 view A has been replaced by the blanket cylinder 7C, provided with its printing blanket 7D, on the rotary support shaft 9 driven by the gear 8 .

Figure 8 view A shows an embodiment of the blanket cylinder 7C, mounted on the rotary shaft 9 driving it. The rotary shaft 9 directly drives the blanket cylinder 7C, locked in rotation by the key 10 and in translation by the stop screws 11. The blanket 7D is pinched between the tension strips 12 and the clamping strips 13, held by screws 13A. The tightening of the screws 14, with a spherical head, provides normal tension to the blanket 7D by screwing into the cylindrical nuts 15, which produces the tilting of the tension strips 12 on the blanket cylinder 7C.

Figure 8 view B, shows the toothed wheel 3A permanently installed on the axis of the blanket cylinder 3 Figure 6. In the case of adaptation of the inking group to existing presses, this toothed wheel is made in two half-pieces to allow its installation without having to dismantle the printing press. Its machining is carried out with extreme precision to obtain a perfect rotation of the teeth, without eccentricity or warping. The screws 3 B maintain the assembly of the two half-wheels and, at the same time, secure the blanket cylinder on the shaft by pinch effect.

Figure 9 shows a partial section of the inking module 16, showing the general principles used to deposit the ink on the blanket cylinder 7C. The flanges 35 supporting the elements of the inking module 16 are attached to the printing press by means of the axes 29A pivoting in the bearings 27 by means of the ball bearings 27B. The plate cylinder 17 rotating in its bearings 17A carries at one end of its axis 17B the keyed gear 17C rotated by the motor gear 3C of the printing press. The gear 36 rotating on its fixed axis 27 actuates the connecting rod 38 by the eccentric pin 39 mounted on a ball joint. The connecting rod 38 in turn drives the lever 40, articulated on the support 40A by the axis 40B and the rollers 41 of which alternately push right and then left the wandering tables 22A and 22B for grinding the ink. These are driven in rotation by the gear 36 and the gear 42, the number of teeth of which allows them to obtain the same circumferential speed as the plate cylinder 17, the ink transfer rollers 23A and touchers 24A being thus trained by simple contact with light pressure. The adjustment of this pressure is obtained by the combined rotations of the eccentric bearings 43 acting on the pressure against the portable table 22A and the eccentric shaft 44 of the inking touch rollers 24A acting on the pressure against the plate of the plate cylinder 17. A end of the eccentric shaft 44 carries a crank 45 which is connected by a connecting rod 46 to the single control lever 47 Figure 10. Each inking touch roller 24A Figure 3 and wetting toucher 24 is likewise connected to the single control lever 47 Figure 10. Depending on its position, it is possible to put out of contact or in contact with the plate cylinder of plate holder 17 Figure 3, the set of ink-touching rollers 24A or all of the wetting touch-up rollers 24. L gear 42 Figure 9 carries at one end a toothed pulley 48 which by means of the toothed belt 49 rotates the toothed pulley 50 keyed on the shaft 51 with a dem ratio multiplication such that the shaft 51 rotates by one turn to each printed format. The cam 52 keyed onto the shaft 51 thus raises at each printing cycle the cam roller 53 fixed at the end of the lever 54. The latter is keyed at one end of the axis 55 whose other end carries, keyed , the lever 56 which thus allows the back and forth movement of the ink take-up roller 26 rotating on the axis 26A fixed on one side on the lever 56 and on the other on the lever 56A articulated on the axis 55A. In the forward movement, the ink take-up roller 26, pressing on the ink ducter 20A of the inkwell 26, is coated with ink which it deposits on the portable table 22B at the end of the return movement. The rotating shaft 51 carries at one end the crank 57 on which the connecting rod 58 fixed to the lever 59 pivots. This lever is pivotally mounted on the axis 20B of the ink-carrying roller 20A by means of the free wheel 60. In its oscillation, the movement of the lever 59 thus rotates a few degrees and in the same direction, thanks to the freewheel 60, the ink-conducting roller 20A which thus comes to coat in the ink reserve 25 whose flow is provided by the adjustment screws 61. The screws 62 and 62A keep the ink reserve 25 closed, which can however be opened for washing by tilting around the axes 63 and 63A. It should be noted that the kinematics of the wetting liquid distribution system is generally carried out in the same way as the kinematics of the ink distribution system. Protective housings 64 and 64A prohibit direct access to mechanical assemblies which could be dangerous for the user.

Figure 10 shows the inking module 16 on which are arranged all the controls necessary for the proper use of the module. The lever 65, with index and graduated scale, regulates the amplitude of the rotation movement of the ink-conducting roller 20A Figure 9 by action on the pawl of the freewheel 60. The lever 65A Figure 10 allows the rotation of the conducting roller manually of ink 20A Figure 9. The screws 61 regulate the coating of the ink conducting roller 20A thus acting in conjunction with the choice of the position of the lever 65 Figure 10 on the quantity of ink deposited on the plate cylinder of plate holder 17 The lever 66, with it seated its index and scale graduated, adjusts the amplitude of rotation of the conducting roller 20 Figure 3 of the wetting liquid thus acting directly on the flow of liquid deposited on the plate cylinder of plate holder 17. The lever 66A allows manually the rotation of the conducting roller 20 Figure 3 of the wetting liquid. The judicious adjustments of the screws 61 FIG. 10 and of the levers 65 and 66 thus make it possible to deposit on the plate of the plate-carrying cylinder 17 the quantity of ink and of wetting liquid best suited to an excellent impression. The unique control lever 47 with four positions, selects the different functions. In the "off" position, the connecting rods 46 Figure 9, not shown entirely for clarity of the drawing, controlled directly by the single control lever 47 Figure 10, push the levers 45 Figure 9 into a position such that the eccentric shafts 44 separate the wetting rollers 24 Figure 3 and ink pads 24A of the plate cylinder 17. In the "wetting" position of the single control lever 47 Figure 10, only the connecting rods 46 Figure 9 controlling the wetting touch rollers 24 Figure 3 are actuated bringing them under pressure against the plate of the plate cylinder 17 thus ensuring its necessary wetting. In the "inking" position, the ink-touching rollers 24A in turn come into pressure against the plate of the plate cylinder 17. It should be noted that these operations are carried out without the plate cylinder 17 Figure 10 coming into contact with the blanket cylinder 7C. Indeed on the axis 47A of the single control lever 47 is wedged a cam 67 acting on the roller 68 of the lever 69 articulated by the axis 70 on a flange 35 of the inking module 16. The lever 69 is supported directly on the frame 1 of the printing press rotating the inking module 16 on its axes 29A of articulation. In the "printing" position, the single control lever 47 rotates the cam 67, the hollow of which pivots the lever 69 and tilt the inking module 16 so that the raceways, called "cords" 17D Figure 9 of the plate cylinder 17 come to bear on the cords 7E of the blanket cylinder 7C. The blanket plate is pressurized, thus allowing transferring the ink from the plate of the plate cylinder 17 onto the blanket of the blanket cylinder 7C. Printing now can be obtained by pressing sheet 5 Figure 3 between the pressure cylinder 4 and the blanket cylinder 7C.

In the context of the invention and using the same means characterizing it in all of its claims, larger format presses can be equipped in the same way.

Claims (10)

1 - Removable printing unit for offset printing presses which can be incorporated during their manufacture or which can be adapted to existing presses, characterized by being made up of an independent inking module 16 comprising all the elements capable of being produced , in a chronological order of operation, wetting and inking an offset plate ready to print a blanket and a removable blanket cylinder 7C also independent. These two basic elements of the printing unit work in combination with all of the mechanisms for feeding, printing, numbering or typographical make-up and reception of the printed sheet.
One of the embodiments of the invention is characterized by the fact of replacing the numbering device fitted to the press with the blanket cylinder of the printing unit working with the inking module 16, of using the drive 8 and pressure adjustment 9B delivered by the press, to obtain, by printing cycle, instead of numbering, a complementary color produced by superimposing colors using the back pressure cylinder 4. In this configuration the inking module 16 rests on the bearings 27. The pressurizing or depressurizing device, for lack of sheet, is obtained automatically by spreading the rotary shaft 9 simultaneously with the automatic stopping of the press. This function is valid in all cases.
In the other form of the invention, the same inking module placed at another location on the press, works jointly with the blanket cylinder 3 thereof, to allow, by printing cycle, to obtain a complementary color and possibly a typographical numbering or additional color.
The inking module takes its movement via the toothed wheel of the power take-off 3A permanently fixed to the axis of the blanket cylinder 3. In this configuration, the bearings 27A support the inking module 16. 2 - removable printing group for offset printing press according to claim 1, characterized in that the printing group 16 can be placed on the press in two positions using the supports 27 and 27A locked by the caps 28 and 28A. 3 - Removable printing unit for offset printing presses according to claims 1 and 2, characterized in that the rotary shaft 9 is used interchangeably and successively to drive the rings 9A supporting the numberers 9B, the machon 9C and the cylinder holder blanket 7C. 4 - Removable printing groups for offset printing presses according to any one of the preceding claims, characterized in that the power take-off 8 drives, in phase with the press, the rotary shaft 9. 5 - Removable printing unit for offset printing presses according to any one of the preceding claims, characterized in that the micrometric adjustment screw 7B allows the pressure of the rotary shaft 9 to be adjusted against the back pressure cylinder 4. 6 - Removable printing unit for offset printing presses according to any one of the preceding claims, characterized in that the toothed wheel 3A is permanently fixed to the shaft of the blanket cylinder 3 to drive the inking module 16. 7 - Removable printing group for offset printing presses according to any one of the preceding claims, characterized in that the printing group, in the case of printing two superimposed colors, replaces and uses all the functions of the numbering and additional printing device typographic. 8 - Removable printing unit for offset printing presses according to any one of the preceding claims, characterized in that its inking module is provided with all the elements necessary to produce, in chronological order, all of the specific functions to get a good impression. 9 - Removable printing unit for offset printing presses according to any one of the preceding claims, characterized in that a pneumatic spring 29 bears on the frame 1 of the press and the lifting arms 30 articulated on the bearings 31 fixed to the frame 1, raise the inking module 16. 10 - Removable printing unit for offset printing presses according to any one of the preceding claims, characterized in that the automatic pressurizing device, by lack of supply of press sheet, operates in different cases printing and that the shaft 9 moves away automatically and thereby prevents dirtying, by printing, the back pressure cylinder 4.

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