FR2788715A1 - DOSING DEVICE FOR A ROTARY PRINTING MACHINE - Google Patents

Abstract

- Dosing device for a rotary printing machine. - The metering device comprises a chamber (3) receiving a fluid and a rotating cylinder (1) immersed in the fluid. According to the invention, an ultrasound transmitter (6) is arranged on a wall of the chamber (3).

Description

The present invention relates to a metering device for a machine

  rotary printing, comprising a chamber receiving a

  fluid and a rotating cylinder immersed in the fluid.

  Metering devices of the indicated type are used in rotary printing machines for metering the supply of ink, wetting fluid or lacquer. Known metering devices of this type are described inter alia in documents DE-43 24 631 C2 and DE-44 10

161 A1.

  For dosing devices of the indicated type, there is the pro-

  that the cylinder surface becomes dirty during operation and

  must therefore be cleaned. Such cleaning therefore requires

  breakage of printing and, after supplying a cleaning fluid to the rotary cylinder, often also wiping of the cylinder. In

  lacquering devices and in flexographic printing we also use

  Lement cylinders, the surface of which is provided with a network. These cylinders become soiled after a long period of use by deposits in the depressions so that, from time to time, intensive cleaning must be carried out. For such intensive cleaning, the network cylinders are dismantled and cleaned in special cleaning installations, for example brush cleaning installations or ultrasonic cleaning installations. An ultrasonic cleaning installation is known from document US Pat. No. 5,291,827 A. In addition, document DD-34,030 discloses an apparatus for cleaning printing cylinders on printing machines, which

  has a suction bell which can be brought into contact with the cylinder

  dre of printing, in which are arranged an injection nozzle for a cleaning fluid and an ultrasonic emitter. The cleaning device is guided on a support and can be moved back and forth on the support,

  longitudinal direction of the impression cylinder.

  The object of the present invention is to allow internal cleaning.

  of the cylinder with a dosing device of the type indicated above

  ment in the printing machine, with reduced cost.

  To this end, according to the invention, the metering device for a ma-

  china rotary printing, comprising a chamber receiving a fluid and a rotary cylinder immersed in the fluid, is remarkable in that a

  an ultrasonic transmitter is arranged on a wall of the chamber.

  Thanks to the arrangement in accordance with the invention of an ultra-light transmitter

  we can clean intensively, both during printing,

  that during an interruption of printing, the cylinder of the delivery device

  wise so that mechanical cleaning by hand or cleaning in

  a separate cleaning installation is not necessary. When the dis-

  positive dosing represents a wetting unit, by operation

  of the ultrasonic transmitter, during printing, you can stop a

  ink on the wetting cylinder and a constant supply of fluid

  wetting can be obtained. If operation of the transmitter

  trasons is not possible during printing, it should be considered as an essential advantage of the metering device according to the invention the fact that, in the machine having a reduced cost, an automatic cleaning of the cylinder can be carried out, without a mechanical treatment of the latter,

by hand.

  The embodiment according to the invention of the dosing device

  sage is also characterized by a reduced installation cost, since

  that the fluid receiving chamber must also be equipped with a

ultrasonic transmitter.

  In a first embodiment, the cylinder includes an overlay

  porous face or provided with a network and the chamber is formed by a chamber scraper with scraper blades arranged spaced apart from each other, the ultrasonic emitter being arranged between the scraper blades on the plate of the chamber scraper.

  In addition, in a second embodiment, the chamber is formed

  mée by a container arranged below the cylinder and the transmitter of ultra-

  sounds is arranged at the bottom of the container.

  Furthermore, advantageously, the ultrasonic emitter is arranged in the form of a surface element on the internal face of the chamber.

  Preferably, the ultrasonic transmitter is arranged on the face ex-

  dull room and the bottom of the room is made in the form of a

oscillating membrane.

  According to another characteristic of the invention, the chamber can be formed by a particular cleaning device, for example a scraper,

  fitted with an ultrasonic transmitter and which can be brought into contact with the cylinder

  dre, for the implementation of a cleaning using a rinsing fluid.

  The device can, for example, also be arranged on a support of the ra-

  chamber cloir, to be able to carry out the cleaning of the cylinder.

  In addition, advantageously, the cleaning device comprises

  carries a box provided with an opening extending along the cylinder, and the edges of the box, which limit the opening, can be brought into contact

  of the cylinder and carry a seal that can be fitted to the cylinder

dre.

  The figures of the appended drawing will make it clear how the invention can be implemented. In these figures, identical references

  denote similar elements.

  Figure 1 is a schematic representation of a device for

  dosage in accordance with the invention and comprising a chamber scraper.

  Figure 2 shows a cleaning device that can be used at

instead of a chamber scraper.

  Figure 3 is a schematic representation of a wetting unit according to the invention and comprising a cylinder metering. Figure 4 shows another embodiment of a fluid container.

  mooring for a mooring unit according to figure 3.

  FIG. 1 shows a dosing device which can, for example, be used in lacquering stations of rotary printing machines

  with leaves. The metering device consists of a cylinder 1, against the

  which can be disposed a chamber scraper 2. The surface of the cylinder 1 is porous or is provided with a fine network and has a high number of very small depressions and located closely next to each other,

  in the form of small cups. In operation, these depressions receive

  the fluid located in the chamber 3 of the chamber scraper 2, for example

  full of lacquer, ink or wetting fluid, and transmit it to a plate cylinder 4 rolling on the cylinder 1. The quantity transmitted

  of fluid is determined in this case by the scooping volume of the depres-

  sions in the porous or lattice surface of cylinder 1. When during

  of the operation, dust gets lodged in the depressions, the vo-

  scooping lume is reduced and thus also the amount of fluid transmitted to the plate cylinder 4, which is not desirable. Therefore, from time to time, a cleaning of the surface of the cylinder 1 is necessary,

  cleaning which also removes the dust adhering to the depres-

  sions. Likewise, at the end of a production, when changing, for example the type of lacquer or cylinder, cylinder 1 must also be

  cleaned up. To be able to quickly and with the desired care the net-

  cleaning, we arrange on the bottom plate 5 of the chamber scraper 2 a

  ultrasonic transmitter 6. The ultrasonic transmitter 6 is located in a

  pressure on the external face of the bottom plate 5, opposite the chamber

  3, approximately in the center, between the removal edges of the raking blades

  key 7 so that the ultrasound generated is oriented directly on the surface of the cylinder 1. The ultrasonic emitter 6 may consist of a single element extending in the longitudinal direction of the chamber scraper

  2. However, two or more individual elements can also be arranged.

  duels, separated from each other, on the bottom plate 5 of the scraper

bedroom 2.

  To clean the cylinder 1, it is rotated and the chamber 3 of the chamber scraper 2 is filled with a cleaning fluid and rinsed. Simultaneously, sound waves are generated using the ultrasonic transmitter 6, the frequency of which is preferably in the range 20 to 40 kHz. In this way, one can quickly obtain a

  effective cleaning of cylinder 1, without the need for additional measures

  mental. With the described embodiment, it is further possible to excite the ultrasonic transmitter 6 during the printing process and thus

  reduce the deposit of dust particles on cylinder 1.

  Instead of the chamber scraper 2, it is also possible to use, for cleaning the cylinder 1, the cleaning device 8 shown in FIG. 2, which, instead of the scraper chamber 2, is arranged in the support of

  scraper chamber 9. The cleaning device 8 consists of a box

  its 21 which comprises, similarly to the chamber scraper 2, a chamber 3 for receiving a cleaning fluid. The box 21 has an opening 22 extending in the longitudinal direction of the cylinder 1, which

  can be closed by the cylinder 1, when the box 21, as shown

  tee in the figure, is brought into contact with the cylinder 1. The edges 23 of the

  verture 22 carry a seal 24 in the form of a ring at 0, which seals the box 21 relative to the cylinder 1. At the bottom of the box

  21, opposite the opening 22, is arranged an ultrasonic transmitter 6.

  The cleaning fluid is brought in and out by the inter-

  medial of openings 25, 26 in the front wall of the box 21. The net-

  the cylinder 1 is cleaned with the cleaning device 8 of the

  same way as with the chamber scraper 2.

  FIG. 3 shows a wetting unit of a rotary offset printing machine. The wetting unit has a cylinder 10

  immersed in the wetting fluid, a metering cylinder 11 and a cy-

  line 12 for applying wetting fluid. The cylinder 10 takes the wetting fluid from a wetting fluid container 13 and transmits it to the cylinder 1 2 for applying wetting fluid, which is in contact with a plate-carrying cylinder 14. The metering cylinder 11 , which rests against the cylinder 10, ensures a uniform distribution of wetting fluid over the

  surface of cylinder 10 and determines the thickness of the wet fluid film

  age. Next to the wetting fluid application cylinder 12 is a bridging cylinder 15 which rests against the wetting fluid application cylinder 12 and an ink application cylinder 16 of a non-ink inking unit more represented. The container 13 is filled or emptied, as necessary, with wetting fluid or a cleaning fluid, by

  I'intermediate a supply link 1 7 and an evacuation link 1 8.

  During printing, the cylinder 10 immersed in the fluid

  wetting takes ink from the wet fluid application cylinder 12

  due to which the supply of dampening fluid is influenced.

  To stop this and to be able to clean the cylinder 10 during the

  pressure, an ultrasonic transmitter 19 is arranged outside on the bottom of the container 13, ultrasonic transmitter 1 9 which can be excited using a generator 20. If the ultrasonic transmitter 19 is excited during printing,

  the ink supplied to cylinder 10 is eliminated and an ink deposit is prevented

  dear. In this way, a constant wetting fluid transmission is obtained and an interruption in printing to clean the cylinder is

  avoided. Cleaning after printing, using a cleaning fluid

  toyage, is also greatly simplified and accelerated by the use of

the ultrasonic transmitter 19.

  As for the embodiment of FIG. 1, the transmitter of

  sections 19, for example a flexible oscillator, can be produced from an elongated element or from several individual elements. In addition, as shown in Figure 4, an ultrasonic transmitter 19 in the form of

  plate can also be arranged, on the internal face, at the bottom of the container

  pient 13, to obtain an even more direct action of the ultrasonic energy

nore on the surface of cylinder 10.

Claims (7)

  1. Dosing device for a rotary printing machine,   comprising a chamber receiving a fluid and a rotating rotary cylinder   giant in the fluid, characterized in that an ultrasonic transmitter (6, 19) is arranged on a wall of the chamber (3).   2. Metering device according to claim 1, characterized in that the cylinder (1) has a porous surface or provided with a network and the chamber (3) is formed by a chamber scraper (2) with scraper blades (7) arranged spaced apart from each other, the ultrasonic transmitter (6) being arranged between the blades   scraper (7) on the bottom plate (5) of the chamber scraper (2).   3. Metering device according to claim 1, characterized in that the chamber (3) is formed by a container (13) arranged below the cylinder (10) and the ultrasonic transmitter (19) is arranged at the bottom of the container (13).   4. Metering device according to one of the preceding claims -   tes, characterized in that the ultrasonic transmitter (19) is arranged in the form   a surface element on the internal face of the chamber.   5. Metering device according to one of claims 1 to 3,   characterized in that the ultrasonic transmitter (6, 1 9) is arranged on the external face of the chamber and the bottom of the chamber is produced in the form an oscillating membrane.   6. Metering device according to one of the preceding claims -   tes, characterized in that the chamber is formed by a particular cleaning device (8) and equipped with an ultrasonic emitter, cleaning device which can be brought into contact with the cylinder (1) for the implementation of cleaning. 7. Metering device according to claim 6, characterized in that the cleaning device (8) comprises a box (21) provided with an opening (22) extending along the cylinder (1), and in that the edges (23) of the box (21), which limit the opening (22), can be brought into contact with the cylinder (1) and carry a seal (24)   can be placed on the cylinder (1).