FR2508846A1 - ROTARY PRESS WITH COILS FOR PRINTING WITHOUT DISCONTINUED AREA - Google Patents

Abstract

THE INVENTION RELATES TO A ROTARY SPOOL PRESS INCLUDING AT LEAST ONE PRINTING GROUP IN WHICH A PRINTING SUPPORT TAPE CAN RECEIVE A PRINTING WITHOUT ZONE OF DISCONTINUITY, THIS PRINTING UNIT BEING EQUIPPED WITH A CYLINDER CARRYING THE IMAGE AND A CYLINDER BACK PRESSURE WITH WHICH THE PRINTING MEDIA TAPE IS PRESSED AGAINST THE PRINTER CYLINDER. THIS PRESS IS CHARACTERIZED IN THAT, TO PROVIDE AN ADDITIONAL PRESSURE CONTACT ZONE BETWEEN THE PRINTING SUPPORT TAPE 2 AND THE PRINTER CYLINDER 4, A ROLLER OR A PRESSURE CYLINDER 7, AND A LENGTH ADJUSTMENT SYSTEM, ARE PROVIDED. OF PATH 6, PROVIDED ON THE COURSE OF BAND 2 BETWEEN THE BACK-PRESSURE CYLINDER 5, AND THE ROLLER OR PRESSURE CYLINDER 7, AND THANKS TO THE FACT THAT THE PRINTER IMAGE B EXTENDS AT LEAST HALF OF THE PERIOD OF ONE OF THE CYLINDERS 4. APPLICATION TO CONTINUOUS PRINTING.

Description

I 2508846

  The invention relates to a rotary web press with at least one printing unit in which a print medium can be printed without a discontinuity area, the printing unit being provided with a cylinder carrying the inked image and a backpressure cylinder with which

  the printing medium is pressed against the printing cylinder.

  German Patent 407,369 discloses a web offset rotary press

  for continuous printing, two sides, strips of paper or fabric.

  With this press, an impression without discontinuity zone is achieved by the use of a large-sized counter-pressure cylinder in contact with which come two blanket cylinders of smaller dimensions, each associated with a plate cylinder of the same size, the inked image to be recorded occupying part of the perimeter of the blanket cylinders In order to be able to carry out a continuous printing, that is to say without hiatus, on a printing support strip passing between the two blanket cylinders and the large counter-pressure cylinder common to them, the two blanket cylinders must come into contact with the counter-pressure cylinder at a distance from each other, distance in relation to the length of the counter-pressure cylinder.

  the printer image they carry on their periphery.

  A disadvantage of this known press is that, for printing without discontinuity area, it is necessary to use two printer groups, namely two blanket cylinders and two plate cylinders, with>

  for each group printing a fountain system and an inking system.

  The object of the present invention is to provide the means of printing a band of great width-without discontinuity, that is to say without hiatus, in a single printing unit According to the invention, this object is achieved thanks to the fact that to realize an additional pressure contact zone between the band

  printing medium and the printing cylinder 4 are provided with a roll or a cy-

  a presser and a system for adjusting the length of the path arranged on the path of the web between the backpressure roll and the roll or the press roll, and by virtue of the fact that the printer image extends to the

  at least half of the circumference of one of the cylinders.

  The invention provides that after the cylinder carrying the printer image (in

  taking as a reference direction that of the scrolling of the printing support tape.

  sion) are arranged for this band a return roller positionable by translation or pivoting and a pressure roller to apply

  again the band against the cylinder.

2 -

  The invention also provides that the offset printing element

  of the printing element comprises a plate cylinder and a pair of counter-pressure cylinder cylinder

  which is the transfer of the band.

  For the printing of the strip in revving, the invention provides a printing unit comprising two plate cylinders as well as two cylinders blanket can be engaged and between which is made the double-sided printing of the tape After passing between the whitening cylinders, the band sees its direction inflected by a trajectory length adjustment system and is applied by a roller

  pressing against one of the blanket cylinders.

  According to a second embodiment of the invention, another system for adjusting the length of the path is defined after the water pressure roll, a system by means of which the print medium is returned to another pressure roller. which applies the opposite side of

  the tape against the other blanket cylinder.

  The invention also provides that several Soilt printer elements arranged one after the other, that the length of the printer image exactly corresponds to half of the periphery of the cylinder which reports it on the tape, that the length adjustment system of trajectory comprises a paper guide roll adjustable position by translation or pivoting, this system may, again according to the invention, be controlled hydraulically or electrically, or be constituted by air blowing ramps According to an embodiment of the invention. invention, powder is insufflated

  between the paper guide roll and the print media tape.

  The invention finally provides for placing in front of the cylinder bearing the printer image a pressure roller applying the strip against this cylinder and, following this pressure roller (always taking as

  sense of reference that of the scrolling of the tape) to arrange a rou-

  return-adjustable reference water by translation or swiveling for adjusting the path length of the web passing between the rolls. Of simpler construction than known rotary presses of the standard type, the web press according to the invention has another essential advantage of requiring for the printing units only the quantity of water normally required in offset technique for a printing element. classic type A saving of 50% 7 agent

  wetting is therefore achieved with respect to printing without a discon-

  This advantage takes its full advantage by means of two printing units.

  meaning, not so much in the economy of commodities as

  essentially in terms of the qualitative improvement achieved.

  Indeed, in the impression without zone of discontinuity like that which

  practical, for example, on paper carriers with perforations

  For example, in the case of continuous paper bundles, the primary quality is the dimensional stability, ie the behavior of the paper strip as regards its extension. Requiring less water than the known printing elements. the printing system according to the invention gives the band a greater dimensional stability, that is to say, in particular, that the elongation undergone by the band during the printing process (especially due to the wetting agent supply) can be kept at an extremely low level One might think that the second impression, ie the second application of the printer image, could lead, when the length given to the image is equal to half the circumference of the cylinder and that the two impressions made are juxtaposed without discontinuity, to differences in intensity of inking visible to the naked eye Practice proves that it is not; it has indeed been found that after interruption, on offset presses, the ink supply, the blanket cylinder was still able to provide a large number of excellent prints whose intensity

  inking did not show any difference detectable with the naked eye.

  In what follows, the invention is explained by means of examples

  illustrated by figures These represent a diagrammatic

  Figure 1, a web offset rotary press for simplex printing,

according to the invention.

  FIG. 2, a rotary press with a four-unit printer coil, for end-to-end printing (double-sided) FIG. 3, a rotary offset press with coils of the type of that of the

  Figure 2, but with another path for the print media tape.

  FIG. 4, a second embodiment of an offset rotary press at

  coils for simplex printing, according to the invention.

  The printing element represented in FIG. 1 is a group of inpres-

  Offset in which a print media 2 can receive a 4-sided print The print set 1 comprises a roll holder

  3, a blanket cylinder 4 and a counter-pressure cylinder 5.

  Print media 2 passes during the printing process

  between the blanket cylinder 4 and the counter-pressure cylinder 5.

  With the known printing units, it is not possible to carry out continuous printing, for example that of bundles of paper

  continuous or wallpaper, because of the presence on the cylinder

  plate 3 and on the blanket cylinder 4 of the discontinuity zone indicated in FIG. 1 by broken lines. To make such an impression, it has been practically so far, as was said at the beginning, to use two printer elements that are either integrated into

  an assembly and having in common a back-pressure cylinder,

placed in series.

  According to the invention, after having passed the blanket cylinder 4 and the backpressure cylinder 5, the printing medium strip is returned by passing around a system for adjusting the length of the path 6 towards the blanket cylinder 4 Using a pressure roller 7 or a second back-pressure cylinder, the carrier strip

  2 already partially printed between the white cylinder

  chet 4 and the backpressure cylinder 5 is again printed on the

even c 8 té.

  The pivoting system 8 diagrammatically shown in FIG. 1 makes it possible to compensate for the length of the path followed by the web, the unprinted portions during the first passage between the blanket cylinder 4 and the counter-pressure cylinder 5 being thereafter when the band of

  paper 2 is returned and then applied for the second time on the cylinder.

  The blanket plate 4 is advantageously supported by the pressure roller 7. It is advantageous for the plate which usually covers the plate cylinder 1 to have a printer image B whose length corresponds exactly to half the circumference of the plate cylinder 3 and therefore

  3.0 half of the perimeter of the blanket cylinder 4, of the same size.

  If, under these conditions, it is made, using the path adjusting device 6, that the loop described by the strip between the blanket cylinder 4 and the counter-pressure cylinder 5 on the one hand, the cylinder the blanket 4 and the pressure roller 7, on the other hand, also corresponds to half the circumference of the plate cylinder (or the blanket cylinder), or at a distance which is an odd multiple - 5 of that which represents this half circumference is obtained by the application of the pressure roller 7 on the printing medium 2, an impression of the image B in the interspaces that were not printed between the blanket cylinder 4 and the backpressure cylinder 5 during the first phase of printing It is therefore possible to perform an uninterrupted printing, that is to say without hiatus, of the support strip by means of a single printing unit of classical construction Of course, the invention does not apply not just one group

  offset printing shown in Figure 1; it is also used

  sand for presses working according to other printing processes,

typography for example.

  The printer image marked B in FIG. 1 and whose length in

  the peripheral direction corresponds to half the circumference of the cylinder

  In this case, when the pressure roller 7 makes the second impression of the strip 2, an overlap which at the limit is almost total is produced, this is the case. In other words, a double total impression is not possible when the invention is applied. In this case, it would not be possible to print continuously. Partial recovery is quite desirable. the printing of wallpapers, especially when certain parts of the printed strip

  must be apparent from the point of view of the intensity of the inking.

  FIG. 2 shows how the invention can be used on a rotary web offset press rotating, comprising a feed group 9 and printing element groups 10, 11, 12, 13 arranged one after the other. In each of these printing groups, the printing unit 2 receives a two-sided printing in one color. The printing units marked 10 to 13 are of identical construction, the invention is explained in the following only in the example of the printing unit 10 This comprises a plate cylinder

  14, an upper blanket cylinder 15 and a cylinder

  lower plate holder 16 and a lower blanket cylinder 17.

  The blanket cylinders 15 and 17 are used for printing and in advance

  of band 2 After passing through the two cylinders carrying

  blanket 15 and 17, the band, as has been said with reference to FIG. 1, voitsa direction inflected by a system of adjustment of the length of its path 6 - 19 and is pressed again against the ion dos rolls door blanket, for example against the blanket cylinder 15, via

a pressing cylinder 18.

  Thus, when it follows the path shown in FIG. 2, the printing support strip 2 receives in each of the printing units from 10 to 13 an unbroken, i.e. without hiatus, printing of its upper face L The use of these four printing groups also makes it possible to print in four colors both the upper face of the strip 2 (without discontinuity zone) and the lower face of this strip.

(with discontinuity areas).

  When following the path shown in FIG. 3 through a web offset press, the construction of which is identical to that of the press of FIG. 2, the printing support strip can receive, according to the invention, an impression without a zone. discontinuity both on its upper face and on its lower face, that is to say on the front and back for this purpose, next to a first return of the band 2 and a new application thereof against the upper blanket cylinder 15, there is provided another return made by a second path length adjustment system 21, which system can be configured as a paper guide roll mounted on side portions with the possibility of a

  position adjustment by translation or pivoting The presence of the

  The method of adjusting the length of the path 21 ensures that the space between

  medial remained unprinted on the underside of the backing tape

  2 when the first impression is made between the cylinder

  blanket 15 and the cylinder 16 will be accurately filled when the lower side of the strip 2 will be applied against the blanket roller 17

  with the aid of another pressure roller 20 Thus, with the form of execu-

  As shown in FIG. 3, it is possible to print the printing medium 2 with the aid of the four printing units marked 10 to 13, in double-sided, without discontinuity zone and in four colors. It is advantageous to automate the pivoting system which is marked 8, in FIG. 1 and which is provided for the device for adjusting the length of the path 6, that is to say to be able to remotely control it. this effect,

  the pivoting mechanism may, for example, be actuated by means of

  33 of a control circuit or a control loop no

  represented by means of an electromagnet or a hydraulically controlled piston

  which has been shown in broken lines Comuie system for adjusting the length of the path, as described in the German patent application

  No. 31 19 398 6 is particularly important.

  The pressure rollers 7 or 18 and 20 necessary for applying the strip to the printing roll a second time can also be executed in the form of normal pressure rolls or roll with a curved part. This curved part, formed by a reinforcement of the diameter in the central part of the roller, must be designed in such a way that a uniform and sufficiently

  can be exerted by the roller along its entire length.

  used as pressure rollers and as path length adjustment systems shall have an oil-repellent coating or a coating with anti-mold spikes to prevent or reduce the

  may smudge the impression still fresh.

  Preferably, the trajectory control systems 8 and 19, as well as 2, are in the form of air-blowing ramps.

  paper guide rollers of the conventional type are used, it is advantageous

  to avoid spotting, to infuse powder between the bands

  fringed printed and paper guide rollers.

  Figure 4 shows another variant of execution in which the

  The printing device 100 comprises a plate cylinder 300, a cylinder

  blanket 400 and a counter-pressure cylinder 500 The printing medium 2 passes around a roller or pressing roll 700 and is pressed a first time by it against the cylinder 400 supporting the printer image By means of a roller 600 to position adjustable by translation or pivoting actuated by a control piston 220 (marked 22 in Figure 1) and a hinge arm 800, the registration setting is performed, then the second printing takes place between the cylinders 400 and 500 The print media strip 2 coming out of the printing element 100

  is thus printed without discontinuity zone.

Claims (11)

1 rotary web press comprising at least one printing unit in which a print media strip can receive an impression without discontinuity zoneprinting group being provided with a cylinder bearing the inked image and a backpressure cylinder with which the printing medium is pressed against the printing cylinder, characterized in that for producing an additional pressurized contact zone between the printing medium (2) and the printing cylinder (4). ;), there is provided a roller or a pressing roll (7); and a system for adjusting the length of the path (6): disposed on the path of the web (2) between the counter-pressure cylinder (5); and the roll or the pressing roll (7); and because the printer image (B) is at least half of the circumference of one of the cylinders 54).   2 rotary press with coils according to claim 1, characterized in that are arranged after the cylinder (4; 15) bearing the printer image (B), taking as a reference direction that of the scrolling of the printing medium (2), a deflection roller (6, 19) with translation or pivoting position for the printing medium (2) and a pressure roller (7; 18) for reapplication   the printing medium (2) against the cylinder (4; 15).   Rotary web press according to claim 1, characterized by   the fact that the printing element (1) is a com-   carrying a plate cylinder (3) and a cylinder matched assembly   counterpressure cylinder blanket (4, 5) through which the transmission takes place   Filling of the print media tape (2).   4. Rotary web press according to claim 1, characterized in that the printing unit (16) is an offset printing unit comprising two plate cylinders (14, 16) and two blanket cylinders (15, 17). that can be engaged, and that between these two last cylinders, the printing support band (2) can receive an impression on both sides.   Rotary web press according to Claim 4, characterized in that after being passed between the blanket cylinders (15, 17), the printing medium (2) is diagonally inflected by means of a control system. length of the path (19) and is applied by a roller   presser (18) against one of the blanket cylinders (for example 15).   Rotary bobbin press according to one of the claims   3 and 4, characterized by the fact that is arranged after the roll   presser (18), taking as meaning that of the scrolling of the printing medium   a further path length adjusting system (20) through which the print medium (2) is fed back to another pressing roller (20) through which the opposite side of the printing medium (2) is applied against the other blanket cylinder (for Example 17).   Rotary web press according to one of the claims   preceding, characterized by the fact that several printing groups   (from 10 to 13) are arranged one after the other.   Rotary web press according to one of the claims   preceding, characterized in that the length of the printer image (B) corresponds exactly to half the circumference of the cylinder (4; 15,16)   transferring the printer image (B) to the printing medium (2).   Rotary web press according to one of the claims   characterized in that the path length adjustment system (8; 19; 21) comprises a position paper guide roller   adjustable by translation or pivoting.   Rotary web press according to one of the claims   characterized in that the system for adjusting the length of the path (8) of the print medium strip can be set in position, by translation or pivoting, by means of an adjustment system of   hydraulic or electromagnetic position (22).   Rotary web press according to one of the claims   precedents, characterized by the fact that the adjustment systems for   jet (8; 19; 21) are air blowing ramps.   Rotary web press according to one of the claims   from 1 to 9, characterized by the fact that between the adjustment systems of the   jet (3; 19; 21) shaped as paper guide rolls and the carrier tape   printing (2), the powder is insufflated.   13 rotary coil press according to claim 1, characterized in that are arranged in front of the cylinder (400) bearing the printer image (B), taking as a reference direction that of the scrolling of the printing support tape (2). )> a pressure roller (700) applying the strip (2) against the cylinder (400) and thereafter a return roller (600) adjustable position by translation or pivoting for the adaptation of the length of the path of the print media tape passing between the cylinders (400,500).