DE8000690U1 - PRINTING MACHINE WITH CONTINUOUS ENDLESS PRINTING RIBBON - Google Patents

Description

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PRINTING MACHINE WITH ENDLESS PRINTING RIBBON

The invention concerns! a printing press with revolving endless Printing tape that carries the printing form (s).

There are printing machines known which, instead of a forme cylinder *, use an endless printing belt on which individual Hcehdruökklisehees or forms are glued. The printing tape only has a support function for these printing forms (see 2.B. DE-PS 1761595). The end and beginning of the tape are connected to one another in the pressure-free space, ie between the clichés by means of interlocking punching and a strip that is glued over. In order to avoid slippage, the edges of the printing tape are provided with perforations, into which the driving pins on the printing cylinder or conveying means attached next to it engage. The disadvantage of such a printing machine is that the letterpress process can be used, since the seams are increased. Furthermore, in addition to the printing templates, printing forms must be produced separately and individually and attached to the printing tape.

The object of the invention is to provide a printing machine with endless printing forms
to create supporting printing tape that can be produced particularly easily and allows the use of the offset printing process in such printing machines.

According to the invention, this is achieved in that the printing tape is simultaneously represents the printing form.

December 27, 1979

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Ott special distributing the erflnduiigsgemüß trained press is / that the pressure band nut a single part and is intrinsically night "printing forms euf as" printing tape must be bonded,

Other features and advantages of the printing press according to the invention check result from dun Unteransprüehen, and the following description / with reference to the drawings, in this

Fig. 1 is a perspective view of the seam of the printing tape

according to the invention,

Fig. 2 is a view of the essential parts of the invention Printing machine / which uses a tape according to FIG. 1 and Fig. 3a and 3b 2we! 90 staggered views of a schematic Representation of the used in the printing press according to the invention Regular drive.

Reference is first made to Figs. 1 and 2, which show a printing tape 9, which can be of variable length and joined at the seam 16 is. The printing tape 9 runs over a forme cylinder 1 and over one in its Distance from the forme cylinder 1 adjustable deflection roller 4,

The printing tape 9 consists of a material which can be processed directly as a printing form, for example aluminum, plastic with correspondingly elastic properties or metal-coated plastic. Although the principle of the invention would be suitable for letterpress and gravure printing, it can be used with particular advantage for flat printing processes, in particular offset printing, the printing templates being transferred directly to the tape using conventional printing technology processes; this means that the usual offset plate is replaced by an endless belt. In this way, not only are the previously necessary individual clichés per page obsolete, but the direct application of the artwork to the printing tape is made considerably easier and faster. It is also impossible for individual clichés to become detached from the printing belt 9.

December 27, 1979

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The thickness of the pressure end 9 begs for the material used. They feature low be using van aluminum ice using a synthetic Taff strip, in which the strength instance known in the OtötehötanurtQ of 0/25 mm Hegen.

Of particular importance for the invention is the formation of the seam 16 / in such a way / that an almost seamless transition is created. In particular, the interface is designed so that there is practically no thickening / where there is a risk of pitting. In principle, the seam should be designed in such a way that the strength properties / in particular the flexural strength at the seam is the same as the rest of the pressure band, so that there is practically a uniform strength curve. The connection seam is expediently applied in the print image between the individual print templates or formats. This means that unintentionally occurring areas of ink carrying ink / for example at the beginning of the overlap seam fall into the trim of the printed product to be produced.

To create a nearly seamless transition, the two ends are of the printing tape 9 is tapered in the area 6 (Fig. 1) and designed to match one another in such a way that that approximately the normal printing tape thickness results at every point. Even though a stepped taper would be possible, the i. Tig. I shown wedge-shaped taper used, for example by salting out the ends is obtained. The two seam ends are then superimposed as shown in FIG. 1 placed / so that there is a relatively wide overlapping area 6. the Interface 16 can then practically no longer be identified.

This means that the lateral ends of the pressure tape are rolled out in a wedge-shaped manner Mareria! Tensions do not cause any disadvantageous deformations of the printing belt, this can be divided into tongues or zones, for example by punching out 18 or the like can be made. The tongues can be sized so that no they correspond to the width of the formats to be printed. For exact gluing or otherwise connecting the two ends of the pressure band, these can be marked with markings or, preferably, alignment holes 17 are provided which match alignment pins, which are attached to a glue device or directly to the printing machine. In

December 27, 1979

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this case, the printing tape ready for printing produced on the surface thereof and prepared in dan ends used directly in the machine and be connected there.

The type of connection depends on the material used, although welding may be an option, an adhesive is preferred, In particular, a polymer plastic adhesive of high elasticity is used, which is already after A high bond strength is achieved in just a few minutes. Due to the wedge-shaped Formation of the pressure tape ends in the area 6 results in a relatively wide adhesive and connecting surface.

As can be seen from FIG. 2, in the printing machine according to the invention, the blanket cylinders required in the offset process as a transfer medium between the forme cylinder 1 and the printing cylinder 2 can be omitted, so that the paper web 5 is in direct contact with the printing belt 9. The printing tape 9 is therefore exposed in such a way that the types can be seen in mirror image on it. The color handing over is then effected directly from the surface of the printing tape 9 to the paper 5. To this end, the pressure cylinder 2, at least on its surface made of elastic material and printed in such a way against the form cylinder 1, that a planar contact between the pressure belt and the paper 5 during the Run results.

FIG. 2 also shows the formats normally provided in printing units 8 and the dampening unit 7.

Although the printing tape can be conveyed in a known manner by means of lateral pin hole guides in order to achieve synchronization with the paper transport, according to the invention, such a pin hole guide is dispensed with; the printing tape 9 is moved by the forme cylinder 1 by frictional engagement. The drive of the forme cylinder 1 and the printing cylinder 2 takes place jointly, namely via a gear 10 to 15 which can be adjusted in its ratio (see Flg.3a and 3b). One such arrangement · hot the advantage that | e Naeh nature of the printing tape 9 and the Poplers be 5 compensated intentionally in purchasing taken slip characteristic ·

To take along the guide of the printing belt 9, a regulating roller 3 is provided.

December 27, 1979

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be seen, the axis of which is angled with respect to the mutually parallel axes of the forme cylinder 1 and the deflection roller 4 is adjustable. For pressure separation an eccentric bushing 14 is provided, through which the pressure cylinder 2 of the Form cylinder 1 can be pivoted away. That

Control gear 15 is connected to the two cylinders 1 and 2 via the gears 11 and 12 connected; it is slip-free and is used to achieve the same peripheral speeds the surface of the printing tape 9 and the paper 5. The printing cylinder 2 is expediently connected to the main drive of the machine via the gear wheel 12 connected or the forme cylinder 1 is about the gear 10 of the main drive driven by the machine. In the first case, the speed of the printing tape is 9 adapted to the paper speed, while in the second case the paper speed the actual speed of the printing belt 9 is to be adjusted.

The inking unit 8 and the dampening unit 7, which run between on and Expiry of the printing tape 9 on the forme cylinder 1 are driven by the main drive in such a way that the inking and dampening rollers are synchronized with the Surface of the printing tape 9 and the paper is guaranteed. In special cases, in the case of a very long printing belt, for example, it can be useful to arrange additional inking and dampening units along the printing belt.

The printing tape 9 is preferably removed by cutting. Re-use is possible by inserting a part at the interface. Alternatively, it is also possible to relax the pressure belt accordingly by moving it the deflection roller 4, so that the printing tape with swiveled inking and damp * works can be removed from the side. Although the two-dimensional pressure between paper 5 and printing tape 9 is advantageous in many cases, it can also be used * - · mttgHenkelten occur in which the pressure cylinder 2 made of metal or similar hard material.

December 27, 1979

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Claims (1)

j - -π — for claims 1. Printing machine with revolving ·· endless printing belt that supports the Printing forms / carries, characterized in that the printing tape is designed at the same time as a printing form. 2. Printing machine according to claim 1, characterized in that the printing tape consists of metal, in particular aluminum. 3. Printing machine according to claim 1, characterized in that the printing tape consists of plastic with metal, for example Aluminum or zinc, can be coated. 4. Printing machine according to one of claims 1 to 3i, characterized in that that the printing tape is made as a planographic printing form, gravure printing form or letterpress printing form. 5. Printing machine according to one of the preceding claims, characterized characterized in that the printing tape has an almost seamless connection. 6. Printing machine according to claim 5, characterized in that the connection of the pressure band is elevation-free. -2- 7. Printing machine according to claim 5 or 6, characterized in that the two seam ends are tapered and designed to match each other that there is an almost bump-free overlap. 8. Printing machine according to claim 7, characterized in that the two seam ends are wedge-shaped, in particular rolled out. 9. Printing machine according to one of claims 5 to 8, characterized in that that provided along the seam at intervals punchings or the like are . 10. Printing machine according to one of claims 5 to 9, characterized in that alignment marks, preferably alignment holes, are provided at the two seam ends. 11. Printing machine according to one of claims 5 to 10, characterized in that that the two seam ends are glued together by means of a polymer plastic adhesive of high elasticity. 12. Printing machine according to one of claims 5 to 10, characterized in that that the two seam ends are welded together. 13. The printing press according uer claims 5 to 12, characterized in that the seam is arranged in the print image between the individual formats. 14. Printing machine according to one of AntprV'Jn 1 to 4, characterized in that the seam of the endless printing belt is designed such that it has the same strength - especially bending fatigue properties as the rest of the belt. 15. Druckmaichln · according to one of the preceding claims with a Form cylinder and a printing cylinder / characterized in that do »over the December 27th 19-9 ι ·· J · • ". Ί • <· ■ · «ί I I I Form cylinder (1) fed directly to the Bend fed via the printing cylinder (2) Popler is in confectionery, 16, printing machine or claim 15, characterized in that the printing cylinder is made of elastic Materiel and is so pressed against the forme cylinder (1), a planar contact dad enfsfeht. 17. Printing machine according to claims S and 16, characterized in that that forme and impression cylinders are moved away from each other 18, printing machine according to one of the preceding claims, characterized in that " internally" pivotable regulating roller (3) is provided for the lateral guidance of the printing bond. 19. Printing machine according to one of the preceding claims, characterized in that that printing cylinder (2) and forme cylinder (1) via a sefzung adjustable transmission are connected and driven. 3On cveeerwendng ee »taenen enosen rt bdndes, characterized in that the printing tape in the gewJiiHtrTferTLange verorbeifet directly to the printing form. Iren according to claim 20, characterized in that the ends SAs »iiaispr.4jfAf H. BL 07/13/81 December 27, 1979