FR2701233A1 - Plate cylinder equipped with a device for lifting a printing plate. - Google Patents

Abstract

The invention relates to printing presses. In order to enable a printing plate (for example 13) to be lifted, preferably in the end region of the printing plate (13) during a plate change, there is provided in the plate cylinder ( 1), below the printing plate (13), holes (for example 5, 16) which can be supplied with compressed air, through which the compressed air can be blown by passing through inlets of compressed air (for example 7) before changing the plate. Main application: rotary offset printing press.

Description

The invention relates to a printing group cylinder equipped with a

device used to lift the

printing plate.

  It must be understood by a group cylinder of im-

  such pressure, preferably a plate cylinder equipped with a tension groove extending in the axial direction, such as that used in rotary offset printing machines. It is known that before the beginning or the the end of each print job in such rotary offset printing machines, it is necessary to make a plate change, ie one or more printing plates on the cylinder must be removed and replaced by new plates, and that at the end of

  production, all plates must be removed.

  Because of the adhesion existing between the plate of

  pressure and the side surface of the cylinder, or by

  the counter-cylinder bearing, rollers always

  as a result of soiling, for example

  creed, the removal of the printing plate

  pressure is difficult, in particular the lifting of the ends of the plates laterally to the groove of the cylinder. Until now, printers have been

  this situation by placing a tool, such as a

  nevis, on the front side, to slightly lift the plate to be removed from the side wall of the cylinder Apart from the minutia with which the problem must be solved by acting in this way, there was also the risk of deterioration of the printing plates

  whereas these plates must frequently be reused

  In addition, the risk of deterioration of the cylinder itself is

not excluded.

  The purpose of the present invention is therefore to

  create a device with which it is possible to

  lifting a plate, especially a printing plate

  of the side surface of a printing cylinder without risk of deterioration, and which

  also be used for the automation of the opera-

plate change.

  This problem is solved by the fact that, to lift the printing plate, a drilling is provided

  axial axis from the front face of the cylinder

  that, to which are connected exit orifices leading

  on the printing plate and between the front

  1 of the plate cylinder and a side frame of the printing unit are arranged compressed air inlets through which the holes or openings

  mentioned above can be supplied with compressed air,

  that the printing plate placed above the

  Exit turns can thus be raised from the plate cylinder. Figures in the attached drawing, given only

  by way of example, make it clear that the invention

  This drawing can be done

  FIG. 1 is a partial section of a cylinder

plate holder; and

  Figures 2 and 3 are two longitudinal sections.

  the (also partial) of a plate cylinder

  for two variants.

  FIG. 4 is a top view of a tower of

  printer groups consisting of two printer groups

perposés.

  In Figure 1, there is shown a cylinder

  plate holder which may be lined with a plate, for example

  at least one offset printing plate 3, the ends, not shown in detail, of this plate,

  being engaged in a groove which extends into the

  axial rection of the plate cylinder 1 for fixing

printing plate 3.

  According to the invention, placed means are

  below the so-called non-printer area that is

  it is necessary to provide on each side of the groove 2, with which the printing plate 3 can be lifted from the plate cylinder 1, preferably

  at an end that is not referenced in detail.

  If the plate cylinder 1 can be lined with several printing plates 13, 14 (Figures 2 and 3), it is advantageous to provide for each of the printing plates 13, 14 a separate device that will allow

  to lift the printing plates 13, 14, preferably

  this individually, it is provided for each

  no printing plates 13, 14, axial bores, 6, which preferably extend first axially

  from the front face 10 of the cylinder

  te-plate, which are in communication with holes

  or outlets 16, 17, extend approximately

  It is advantageous to predict, roughly in

  the vicinity of a side wall, not referenced in de-

  tail, groove 2, and below zone 4, not

  primante for each of the plates 13, 14, several

  exit vertices of this nature, 16, 17, placed

  one after the other in the axial direction.

  According to the invention, for lifting the ends

  printing plates 13, 14, openings or perforations

  5, 6, 16, 17 are fed with a liquid or gaseous medium, preferably with compressed air, to allow the printing plates 13, 14 to be lifted in at least one location, preferably in the region of 'a

  end of the plate, in view of the exchange operation

plate.

  For this purpose, FIG. 2 shows, at a distance from the end face 10 of the plate cylinder 1, feeds

  compressed air in a fixed position, 7 and 8 respectively.

  The supply of compressed air 7 is arranged in the

  axial drilling area 5 provided for the printing plate.

  13 and the supply of compressed air 8 in the region of

  axial drilling 6 provided for the plate 14.

  the compressed air feeders 7, 8 need not be moved for the plate changing operation, and can therefore be arranged in a fixed position in a side frame.

  9 for the supply of compressed air, as this is

  also indicated at 11 and 12 in FIG.

  Alternatively, according to Figure 3, it is also possible to place the compressed air supply 7, 8 to the right of the corresponding holes 5 or 6 respectively, when the plate cylinder 1 is stopped, and it is then rational to individually control the compressed air supply 7, 8, for example by valves

  traditional pneumatic or electromagnetic

  this is indicated but not referenced in detail on the

figure 3.

  In an equivalent way and, consequently, by applying the idea which is at the base of the invention, it

  It is possible to use mechanical parts, for example

  ple, pushers that are pushed through the openings

  output by an electromagnetic force, for

lift the printing plate 3.

  It goes without saying that the number and arrangement of the different holes are calculated according to the case

application considered.

  These devices are usable both for machines with a width of two plates and for

  machines with a width of four plates.

  In the case of machines with a width of two plates, it is possible to perform the service on one side.

  In machines with a width of four

  two plates can be handled independently.

  from one side to the other, that is to say two

  printers can simultaneously implement the

this and the removal of the plates.

  Such a machine with a width of four

  4 shows two printing groups 49, 50 superimposed in a tower of

  printers, with the plate cylinder 1 being

  no additional printing plates 18, 19 in addition to the printing plates 13, 14 The plate cylinder 1 is journalled between two side frames, 21 Similarly, above the plate cylinder 1, is journalled a plate cylinder 22 which is likewise lined with four printing plates 23 to 26

  plate cylinders 1 and 22 are pressurized

  The transfer cylinders 27 and 28, respectively, print a printing medium strip according to the blanket printing principle. In the printing unit 50 disposed above the printing unit 49, a print medium strip is printed by plate cylinders 29, 30 which are lined with printing plates 31 to 34 or 35 to 38 respectively, with

  via transfer cylinders 39, 40.

  The two printer groups 49, 50 are

  for one person on duty, each from a

  plane 41 or 42 In the side frames 20, 21, are arranged

  displays associated with the correct printing plates

  respondents 13, 14, 18, 19; 23 to 26; 31 to 34; 35 to 38, the displays 43, 44 indicating, for example, the

  placing printing plates 13, 14 on the cylinder

  te-plate 1 On the occasion of a change of production, each of the printing plates 13, 14, 18, 19; 23 to

  26; 31 to 34; 35 to 38 can be released individually-

  plate cylinder 1, 28, 29 or 30 respectively.

  by means of an electropneumatic control valve or

  electromagnet belonging to a compressed air line

  Awarded 7, 8 (see Figure 3) which corresponds

  or by a mechanical element that can be

  for example, electromagnetically

  effect, each of the valves or each mechanical element

  connected by a control line to a programming unit provided on the

  work preparation, which is, for example,

  ple, at the printing preparation station In this programming unit, a diagram can be programmed

  ejection of the plates, according to which the plates of

  pressure to change 13, 14, 18, 19, 23 to 26, 31 to 34, 35 to 38 are released after the completion of a first

  print job Optical indicators, for example

  light-emitting diodes, such as light diodes

  Nescentes 45, 46 corresponding to the printing plates 13, 14, indicate to the printer which plates among the printing plates 13, 14, 18, 19, 23 to 26, 31 to 34, 35 to 38 must be changed. the printer then takes the printing plate which has already been detached from the lateral surface of the plate cylinder 1, 22, 29, 30 considered by a pneumatic or mechanical action, and replaces it with a new printing plate. a release switch corresponding to the

  exchanged printing plate, for example, the switching

  release plate 47, 48 corresponding to the printing plates 13, 14, if these printing plates 13, 14 have already been exchanged, it confirms the order of

  plate change This prevents the macine from printing

  sea is set in motion while the plates

  of spare parts are still on the cylinders.

  Plate holders 1, 22, 29, 30 By confirming the order by means of the release switch and switching off the corresponding light-emitting diodes,

  the printer ensures the state of readiness for the pro-

  production of the printing machine and the good condition of the

  This ensures that all plates that have been automatically disconnected have also been actually removed and that the new printing plates are mounted ready for production This indication relieves the printer of any further consideration in this operation. constitute

  release switches (keyboard-film).

Claims (8)

R E V E N D I C A T IO N S   1 plate cylinder equipped with a device for lifting a printing plate, characterized in that, to lift the printing plate (for example 13), there is provided an axial bore (for example 5) which starts from the front face (10) of the plate cylinder   (1), to which are connected outlet openings (16) con-   to the printing plate (for example 13) and   between the front face (10) of the carrier cylinder   that (1) and a lateral frame (9) of the printing unit are arranged compressed air supply lines (for example 7) through which the above-mentioned bores or openings (5, 16) can be supplied with compressed air,   so that the printing plate (for example 13)   placed above the outlet openings (for example 16) can thus be raised from the plate cylinder (1). 2 plate cylinder according to claim 1, characterized in that a plurality of printing plates   (13, 14) can be positioned on the cylinder   te-plate (1), and that each of these plates, leads   an axial bore (5, 6) which can be controlled individually.   so that the printing plates (13, 14)   can be raised individually by means of   corresponding output values (16, 17).   3 plate cylinder according to claim 1 or 2, characterized in that the compressed air supply (7, 8, figure 2) are arranged at a distance from the face frontal (10, figure 2) and fixed.   4 plate cylinder according to claim 1 or 2, characterized in that the compressed air supply pipes (7, 8, 3) provided in front of the face   (10) of the plate cylinder (1) can be applied   against axial drilling (5, 6).   Plate cylinder according to Claim 4, characterized in that the compressed air supply (7,   8) can be ordered individually by van-   pneumatically or electromagnetically.   6 plate cylinder according to one of the   cations, characterized in that the openings   output rests (16, 17) are arranged under a non-printer area (4), and are juxtaposed in the direction axial axis of the cylinder.   7 plate cylinder according to claim   6, characterized in that a non-printed area is provided   mantle (4) on each side of the groove (2).   8 Plate cylinder, in particular according to the   claim 1, characterized in that, in use,   placement of the lifting of the plate cylinder, by compressed air, mechanical elements such as electromagnetically controlled pushers, placed in the   outlet openings (eg 16).   9 Device mounted in an offset rotary printing machine comprising a plate cylinder (1, 22, 29, 30) according to claim 5 or 8, characterized in that the valves of the compressed air lines (7, 8) or the mechanical elements are connected to a programming unit by which can be programmed   a plate ejection scheme, according to which the   printing plates (13, 14, 18, 19, 23 to 26, 31 to 34;   35 to 38) to be changed are released on the cylinders   plates (1, 22, 29, 30) for the change of produc-   by electropneumatic or electromagnetic control   as valves or by electromagnetic control of the mechanical elements, and in that displays (43, 44) are provided to indicate the plate ejection scheme.   Device according to claim 9, characterized   characterized in that the displays (43, 44) are arranged in the side frames (20, 21) of the printing unit and that indicator means (45, 46) are provided for identifying the printing plates (13, 14). , 18, 19; 23   at 26; 31 to 34; 35 to 38) to change.   Device according to claim 9 or 10, characterized in that the printing plates (13, 14,   18, 19; 23 to 26; 31 to 34; 35 to 38) to be changed, are as-   release switches (47, 48) and that the printing operation can be continued only after exchange of the printing plates (13, 14, 18,   19; 23 to 26; 31 to 34; 35 to 38) and actuation of the   corresponding release mutator (47, 48).