EP1827831B1 - Printing plate cylinder with exchangeable sleeve - Google Patents

Description

The invention relates to a printing plate cylinder of a flexographic printing machine according to claim 1.

Under pressure plate cylinder are understood in this document any types of printing cylinders that carry a printed image. Printing plate cylinders are often composed of different cylindrical elements. In general, a rotatably hinged to the machine frame base mandrel forms the core of such a printing plate cylinder. It is clear that this mandrel is applied to changing jobs with different printing sleeves, which carry different print images. For this purpose, the pressure sleeve is pulled over the base mandrel.

In addition to these pressure sleeves and adapter sleeves are known, which are also drawn over the base mandrel and adjust the circumference of the cylinder core thus formed to the required pressure length. Often, another adapter cylinder or a pressure sleeve is pulled over this adapter sleeve either again. Such approaches are known for example from flexographic printing. In particular in packaging flexographic printing one has to deal with many different print lengths, which require many different adapters. The associated print jobs are often satisfied with central cylinder flexographic printing presses. Among these machines there are numerous adapter machines. The printing sleeves of these machines often carry a Drucksleeve or a printing plate from a flexible material characteristic of flexographic printing.

It is known that in all multi-color printing processes there is a need to perform register control. For this purpose, the position of the printed images in the different inking units must be coordinated. Therefore, the position of the print images to the main spine of the machine control or the operator must be known. Therefore, in usually the base mandrels of the printing cylinder on register pins that protrude beyond the peripheral surface of the mandrels. The applied to the base mandrels sleeves have recesses into which the pins reach into or engage when the sleeve has reached its desired position to the mandrel. In this way, the angular position of the sleeve is adjusted and fixed to the mandrel. If this sleeve is an adapter sleeve, then at least one further sleeve - namely at least the pressure sleeve - must be applied to this sleeve in a fixed angular position to the adapter sleeve and thus to the base mandrel. For this purpose, the adapter sleeve then again has a register pin, which projects beyond its outer circumference and engages in a recess provided for this purpose of the further sleeve when this has reached its desired position. This form of Vorregisterung has long been known and well-established both in so-called direct-drive printing machines, where each plate cylinder has its own drive, as well as in machines where there are geared connections between different cylinders.

• Druckplattenzylinder, welcher beim Rüsten der Druckmaschine zumindest aus folgenden zylinderförmigen Elementen zusammengesetzt wird:
  • einem Zylinderkern, der drehbar in der Druckmaschine gelagert ist, und
  • einer Hülse, die zumindest teilweise über den Zylinderkern ziehbar ist,
  • wobei die Winkellage dieser beiden Elemente zueinander einstellbar mit folgenden Mitteln justierbar ist:
  • einem männlichen Registerelement, welches an eines der beiden zu justierenden Elemente angelenkt ist,
  • einem weiblichen Registerelement, welches Bestandteil des jeweils anderen zu justierenden Elements ist,
  • wobei beide vorgenannten Registerelemente in Wirkverbindung miteinander stehen, wenn sich die zu justierenden Elemente in ihrer Solllage zueinander befinden.

Platen cylinders composed of such base mandrels and sleeves and thus pre-aligned or pre-registered can be described as follows:

• Printing plate cylinder, which is composed during assembly of the printing press at least from the following cylindrical elements:
  • a cylinder core, which is rotatably mounted in the printing press, and
  • a sleeve which is at least partially drawable over the cylinder core,
  • wherein the angular position of these two elements is adjustable to each other adjustable by the following means:
  • a male register element which is articulated to one of the two elements to be adjusted,
  • a female register element which is part of the other element to be adjusted,
  • wherein both aforementioned register elements are in operative connection with each other when the elements to be adjusted are in their desired position to each other.

It should be noted that under a cylinder core in the above sense, the base mandrel will often be understood. However, the term cylinder core in the sense of this document also includes a base mandrel which has already been subjected to one or more sleeves. A male register element will often be in the form of a pin or other protrusion which projects beyond the outer circumference of the cylinder core or the inner circumference of another sleeve. A female register element is able to enter into an operative connection - according to the invention a positive connection - with the male register element.

When setting up or assembling these printing plate cylinders according to the prior art, however, damage occurs both on the register pins and on the sleeves. This is due to the fact that the sleeves are not pushed faithfully to the cylinder cores, so that the female register elements - primarily recesses - miss the register pins, and at the end of Aufschiebbewegung to collisions between the edges of the sleeves and the male register elements - so far usually pins - comes. Damage both to the register elements and at the edges of the pushed sleeves are the result.

• Beispielsweise ist aus DE 41 40 768 A1 ein Druckformzylinder einer Offset-Druckmaschine bekannt. Eine hülsenförmige Druckform wird unter Aufweiten mittels Druckluft auf den Druckformzylinder geschoben, d.h. die Fixierung der Druckform gegenüber dem Druckformzylinder erfolgt mittels Reibschluss. Zur Registereinstellung sind Passlochbohrungen 4 vorgesehen.

For the design of the register elements, various solutions are known from the prior art:

• For example, it is off DE 41 40 768 A1 a printing form cylinder of an offset printing machine known. A sleeve-shaped printing forme is pushed under expansion by means of compressed air onto the printing forme cylinder, ie the fixing of the printing forme to the printing forme cylinder takes place by means of frictional engagement. For register setting pass hole holes 4 are provided.

EP 1 155 838 A2 also describes a printing form cylinder of an offset printing press. The printing form cylinder has a gap 20 in the axial direction, in which one or more printing plates are clamped.

Out DE 92 11 483 U1 a device for aligning a cliché cylinder outside a flexographic printing machine is known. The alignment of the sleeve (ie the printing form) via an optical device. The sleeve is then locked via fitting pieces and clamping rings relative to the plate cylinder.

Out EP 782 919 A1 a printing form cylinder of an offset printing press is known, onto which a printing form is pushed. To fix the side register in the axial direction serves as a stop a pin. In addition, an automatic motor control is provided for fixing the circumferential register in the circumferential direction. When the printing form cylinder has reached its desired position, the fixing of the printing forme cylinder takes place by means of frictional engagement by a conical pin.

In the EP 782 919 A1 described alignment of a printing forme cylinder is very expensive if this is done outside a printing press or must be made, as then a motor control must be provided to determine the circumferential register outside the printing press.

The object of the invention is to reduce the above-mentioned damage according to the prior art in a printing plate cylinder of a flexographic printing press.

This object is achieved by a printing plate cylinder of a flexographic printing machine according to claim 1 and a method for equipping a printing plate cylinder of a flexographic printing machine according to claim 6.

Further advantageous embodiments of the printing plate cylinder according to the invention are given in the dependent claims 2-5.

According to the invention it is provided that at least one of the two register elements is articulated movably on the respective element to be adjusted.

According to a further preferred embodiment it is provided that the movable register element is articulated movably in the axial direction z of the printing plate cylinder.

According to a further preferred embodiment, it is provided that the movable register element is articulated movably in the circumferential direction φ of the printing plate cylinder.

According to a further preferred embodiment it is provided that the movable register element is retractable in the peripheral surface of the printing plate cylinder.

According to a further preferred embodiment it is provided that the movable register element is the male register element, which is in operative connection with a spring element which provides a restoring force, which moves the register element into the opening of the sleeve provided, if this (sleeve) in their Target position is located on the printing plate cylinder.

According to a further preferred embodiment, it is provided that the register element is a spring element.

According to a further preferred embodiment, it is provided that the cylinder core has a stop which has a larger stop surface with the sleeve than the male register element.

According to a further preferred embodiment it is provided that the stop surrounds the circumference of the cylinder core.

Fig. 1a

Einen Schnitt A-A durch einen erfindungsgemäßen Druckplattenzylinder während einer Phase des Rüstvorgangs

Fig. 1b

Einen Schnitt A-A durch denselben erfindungsgemäßen Druckplattenzylinder wie in Figur 1a während einer Phase des Rüstvorgangs

Fig. 2a

Einen Schnitt A-A durch denselben erfindungsgemäßen Druckplattenzylinder wie in Figur 1a während einer anderen Phase des Rüstvorgangs

Fig. 2b

Einen Schnitt B-B durch denselben erfindungsgemäßen Druckplattenzylinder wie in Figur 1 a während einer anderen Phase des Rüstvorgangs

Fig. 3a

Einen Schnitt A-A durch denselben erfindungsgemäßen Druckplattenzylinder wie in Figur 1a am Ende des Rüstvorgangs

Fig. 3b

Einen Schnitt D-D durch denselben erfindungsgemäßen Druckplattenzylinder wie in Figur 1 a am Ende des Rüstvorgangs

Fig. 4

Einen Schnitt in der axial-radialen Ebene durch ein anderes Ausführungsbeispiel eines erfindungsgemäßen Zylinders

Further embodiments and details of the present invention will become apparent from the embodiments and the subject description. The individual figures show:

Fig. 1a

A section AA through a printing plate cylinder according to the invention during a phase of the setup process

Fig. 1b

A section AA through the same pressure plate cylinder according to the invention as in FIG. 1a during a phase of the set-up process

Fig. 2a

A section AA through the same pressure plate cylinder according to the invention as in FIG. 1a during another phase of the setup process

Fig. 2b

A section BB through the same inventive printing plate cylinder as in FIG. 1 a during another phase of the setup process

Fig. 3a

A section AA through the same pressure plate cylinder according to the invention as in FIG. 1a at the end of the set-up process

Fig. 3b

A section DD through the same pressure plate cylinder according to the invention as in FIG. 1 a at the end of the set-up process

Fig. 4

A section in the axial-radial plane through another embodiment of a cylinder according to the invention

Fig. 1 shows a printing plate cylinder 1, which is being prepared. For this purpose, an adapter sleeve 2 is pushed onto the cylinder mandrel 3 in the axial direction z of the printing plate cylinder. On the adapter sleeve 2 sits the pressure sleeve 4, on which the cliché 5 is mounted. It is a flexographic printing cylinder.

In FIG. 1a It can be seen that the angular position between the male register element, here the pin 6, and the female register element, here the recess 7, has been set correctly. Upon further pushing the adapter sleeve 2 on the cylinder core 3, the adapter sleeve 2 reaches the position in the FIGS. 3a and 3b is shown. Here, the male adapter element, the register pin 6, in the female register element, the recess 7, reach into and thus determine the angular position of the cylinder core 3 to the adapter sleeve 2. In the previous further sliding process, the adapter sleeve 2 has been moved against the stop 8. In this way, the axial movement of the sleeve 2 is terminated.

The Figures 1b, 2a, 2b . 3a and 3b show the same embodiment of a printing plate cylinder according to the invention as the FIG. 1a , However, in FIG. 1b the initial position of the setup process different than in FIG. 1a , In FIG. 1b the angular position of the recess 7 relative to the register pin 6 is different. For illustrative reasons, these two elements were shown rotated by 180 °. However, it will be apparent to those skilled in the art that smaller angle deviations will occur in practice, however, already leading to damage in prior art printing plate cylinders. Despite the rotation of the adapter sleeve 2 relative to the cylinder core 3, the adapter sleeve 2 is moved against the stop 8. In this case, the register pin 6 is pressed down by the edge of the adapter sleeve 2. In this case, a spring element 9 is tensioned. The resulting situation is in the FIGS. 2a and 2b shown. The adapter sleeve 2 has reached the stop 8, the male register element 6 is depressed, the female register element is still displaced by 180 ° relative to the male register element 6. Therefore, the adapter sleeve 2 is displaced in the circumferential direction φ until in the FIGS. 3a and 3b situation occurs. Here, the adapter sleeve 7 has been rotated until the recess 7 arrives at the adapter pin 6, so that an operative connection can occur between these two elements. This is brought about in this case by the spring 9 by these 9 presses the register pin 6 in the recess 7. Thus, the setup process, as far as the adapter sleeve and the cylinder core, ended.

In FIG. 4 another embodiment of a printing plate cylinder according to the invention is shown. Here, however, the male register element 10 does not have the shape of a pin, but the entire male register element is a spring plate 10, which in FIG. 4 just flattened by the edge of the adapter sleeve 2. Also in FIG. 4 It can be seen that this embodiment of a printing plate cylinder according to the invention has an adapter sleeve 2 with a recess 7. This recess 7 also serves as a female register element.

In the in FIG. 4 As shown, the adapter sleeve has already reached its axial end position on the stop 8. Then she becomes in her circumferential direction rotated relative to the mandrel until the recess 7 reaches the register element 10 and this jumps over the peripheral surface of the cylinder core by its spring force and engages in the recess 7, wherein the angular position of the adapter sleeve 9 is fixed relative to the cylinder core 3.

Among other things, in the dependent claims is still disclosed that there are alternatives to the embodiments shown and also to the described setup methods. Thus, for example, register elements are conceivable, which are displaceable only in the axial direction. Moreover, it is conceivable to stamp out only the female register elements in any way. The stops can be represented differently than in the present embodiments. So it is possible, for example, to introduce pins in the cylinder core, which take over the function of the stop. It is advantageous here to design the stop surface of these pins larger than that of the previously used register pins in order to make the pressure effect, which occurs in the collision of the adapter with these pins, less than the collision pressure that has been incurred in the collisions with the register pins. The adjustment of the angular position of the cylinder core and the adapter sleeve to each other can of course also be made by the cylinder core is rotated relative to the adapter sleeve. This is easily possible, since just the cylinder core is designed to be rotatable in rotary printing machines. The attachment of the male register element to the adapter or a further sleeve and the female register element on the cylinder core is advantageous in certain applications. Especially limited are the representations made in the present drawings of the invention in relation to the cylinder core and the adapter sleeve. It has already been mentioned in the introductory description that the term cylinder core can already be understood as meaning a unit comprising a base mandrel and an adapter sleeve. In this case, the outer peripheral surface of the adapter sleeve would be provided with a further register element. The next sleeve, which is pulled over the adapter sleeve, would then have the counterpart to this register element and would be designed in the manner according to the invention.

Claims (6)

1. Printing plate cylinder (1) of a flexographic printing press,
   with a cylinder core (3) which is rotatably mounted in the printing press,
   with a sleeve (2) displaceable on the cylinder core, wherein the sleeve (2) is displaceable in the axial direction (z) and in the circumferential direction (ϕ) with respect to the cylinder core (3), wherein the cylinder core (3) comprises a stop (8) which the sleeve (2) reaches at its end position in the axial direction (z), and wherein the sleeve (2) is displaceable in its circumferential direction (ϕ) to its reference position when it reaches its end position in the axial direction (z),
   with a register element, which is part of the cylinder core (3), and
   with a counterpart to this register element which is a component of the sleeve (2),
   wherein the register element is pivotally mounted on the cylinder core (3) or the counterpart is pivotally mounted on the sleeve (2) in such a manner, that there is a form fit between the register element and the counterpart, when the cylinder core (3) and the sleeve (2) are in their reference position with respect to each other.
2. Printing plate cylinder according to claim 1, wherein the register element (6, 10, 11) is movably mounted on the cylinder core (3) and may be pressed down by the pushed-on sleeve.
3. Printing plate cylinder according to claim 2, wherein the register element (6, 10, 11) is in operative connection with a spring element (9) which provides a restoring force, so that the register element (6, 10, 11) is form-fittingly inserted into the counterpart (7), when the cylinder core (3) and the sleeve (2) are in their reference position with respect to each other.
4. Printing plate cylinder according to one of the claims 1 - 3, wherein the cylinder core (3) consists of a rotatably supported basic mandrel.
5. Printing plate cylinder according to one of the claims 1 - 3, wherein the cylinder core (3) consists of a rotatably mounted basic mandrel, which is subjected to one or more adapter sleeves.
6. Method for setting up a printing plate cylinder of a flexographic printing press,
   wherein a sleeve (2) is pushed onto a cylinder core (3) in the axial direction (z) until it reaches its end position at a stop (8) of the cylinder core (3) in the axial direction (z),
   wherein the sleeve (2) is displaced in the circumferential direction (ϕ) opposite the cylinder core (3) until the cylinder core (3) and the sleeve (2) are in their reference position with respect to each other,
   wherein the cylinder core (3) comprises a register element, while the sleeve (2) comprises a counterpart to this register element, wherein the register element is pivotally mounted on the cylinder core (3), or the counterpart is pivotally mounted on the sleeve (2), in such a manner, that a form fit occurs between the register element and the counterpart, when the cylinder core (3) and the sleeve (2) are in their reference position with respect to each other.

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