GB2290502A

GB2290502A - Continuous multiprinting machine

Info

Publication number: GB2290502A
Application number: GB9412116A
Authority: GB
Inventors: Martonez Francisco Cremades
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-11-04
Filing date: 1994-06-16
Publication date: 1996-01-03
Also published as: NL9300468A; GB9412116D0; PT101222A; ES2049143R; BR9301184A; FR2702704A1; ES2049143A2; BE1006806A6; DE4310367A1; ES2049143B1; CA2092034A1

Description

A CONTINUOUS MULTIPRINTING SYSTEM AND MACHINE The inventions refers to a continuous multiprinting system, wherein the material to be printed moves successively along a series of printing stations. It also refers to a machine incorporating said system and operating according it.

The technical problem to be solved relates mainly to the control and adjustment of the continuous printing machines, such as, for example, multicolor printing, by means of a sequence of printing stations or units (rollers).

On this type of machines, the material to be printed, for example, paper, fabric or others, passes along a plurality of printing atations, composed generally of rollers, on each of which a color or graphic motif is successively printed until composing the final desired figure. It is necessary, therefore, to initially prepare or adjust the machine according to the size and colors for obtaining the graph to be printed, this operation being carried out usually by changing the printing rollers by others having an adequate diameter, or varying the quantity of said rollers. It is, also, necessary a fine printing adjustment, which requires a boring watch task of the longitudinal and transverse position of the material and each one of rollers.All these preparation and adjustment operations are required for every particular printing work, which increases both times and costs of standing machine.

In the state of the art, there are described systems and devices making easy to adjust printing stations. For example, the European Patents 0313531 and 0364424 describe a method for adjusting the position of the material to be printed on each of the printing stations, based on the reading and record of an initial value of the material position to be printed, and of the position value on each of the printing stations, comparing successively said values to obtaing eventual discrepancies which are corrected from the first printing station. The method is improved by adding step to step motors to each printing station, the values of said motors being also read and recorded.

Both the system and machine of the invention start also from the principle of determining the position of the material to be printed on each of printing stations, according to the distance to be traversed between said stations, but the aim being assuring a correct position in each stations and the use of simplest and cheapest means than those described until now, and providing highly reliable issues.

It would be desirable to be able to provide a multicolour printing system and machine not requiring a frequent replacement of the printing rollers according to the size of the work to be done.

According to the invention, a continuous multiprinting system, wherein a strip of the material to be printed moves along a series of printing stations, consisting usually of printing rollers, at each of them the material to be printed is successively given a color or graphic motif, characterizes in that it comprises:: - driving rollers for driving the strip of material to be pinted,- constituted by at least a pair of rotating rollers between which the material to be printed moves, the rollers of each pair being axially and vertically aligned and each roller presenting a raised cylindrical portion and a recessed cylindrical portion being adjustable at will the relative position of each ro llers in each pair, so that the material to be printed is driven when it engages the respective raised portions of each roller and it stops when, at the turning of each roller, the recessed portions match;; - printing means of the material strip to be printed, which are constituted by one or more consecutive pairs of printing rollers between which the material to be printed moves, the rollers of each pair being axially vertical aligned and each roller presenting a raised cylindrical portion and a recessed cylindrical portion, the relative position of each roller in each pair being adjustable at will, so that the material to be printed is printed when it engages the respective raised portions of each roller, of which at least one is fitted with relief or printing .clinch8, and it stops when, at the turning of each roller, the recessed portion match;; - tensioning means for tensioning the material to be printed, working in opposition to the feeding of said material when it is driven along the printing stations, and maintaining taut the material to be printed when no driving force is exerted; - marking means for marking the position of the material to be printed at a moment preceding to start receiving a printing at each of said stations, the material to be printed being stopped at said moment, since it meets a coincidence position of the recessed portions of the driving rollers, and - retaining means for retaining the material to be printed in the marked position corresponding to the moment preceding to be printed in each of said stations.

In a preferred embodiment of the system, the retaining means use physical signals effected by the marking means.

In accordance with the system according to the invention, the distance or gap between printing stations and between marking and retaining means is adjustable at will. Preferably, the distance or gap between printing stations and between marking and retaining means is adjustable according to the relative position selected between each pair of driving rollers.

As per the system of the invention, beside the pairs of driving and printing rollers, it can be foreseen pairs of rollers for dieing the material to be printed, or substituting such dieing rollers for the printing ones.

The present inventions refers also to a continuous multiprinting machine, wherein the strip of material to be printed moves along a series of printing stations, composed usually of printing rollers, at each of which the material to be printed is given successively a color or graphic motif, characterized in that it comprises:: - driving means of the strip of material to be printed, constituted by, at least, a pair of rotating rollers between which the material to be printed moves, the rollers of each pair being aligned axial vertically, and presenting each roller a raised cy lindrical portion and a recessed cylindrical portion, being adjustable at will the relative position of each roller in each pair, so that the material to be printed is driven cuando it engages the respective raised portions of each rollers, and it stops when, at the turning of each roller, the recessed portions match;; - printing means for printing the strip of material to be printed , constituted by one or more consecutive pairs of printing rollers between which the material to be printed moves, the rollers of each pair being axial vertically aligned, and presenting each roller a raised cylindrical portion and a recessed cylindrican portion, being adjustable at will the relative position of each roller in each pair, so that the material to be printed is given a impring when it engages the respective raised portion of each roller, of which one is, at least, fitted with a relief or printing click or plate, and it stops when, at the turning of each roller, the recessed portions match;; - tensioning means for tensioning the material to be printed, working in opposition to the feed of said material when it is driven along the printing stations, and they maintain taut the material to be printed when no driving force is exerted; - marking means for marking the position of the material to be printed at a moment previous to start receiving a printing at each of said printing stations, the material to be printed being stopped at said moment, since t corresponds to a coincidence position of the recessed portions of the driving rollers, and - retaining means for retaining the material to be printed in the marked position corresponding to a moment previous to start receiving a printing at each of said stations.

In a preferred embodiment of the machine, the distance or gap between printing stations, and between marking and retaining means, is adjustable at will. Preferably, said distance or gap between printing stations and between marking and retaining means is adjustable according to the relative position selected between each pair of driving rollers.

On the machine of this invention, besides pairs of driving rollers, it can be foreseen pairs of dieing rollers to die the material to be printed, or to substitute said dieing rollers for the printing ones.

Preferably, on a machine according to the invention. the tensioning means are constituted by a hollow roller, which is drilled and rotates in a sense as opposed to the feed of the material, and which is mounted in a casing which is open at the area corresponding to the contacting sliding of the material to be printed on said roller, which, when rotating, exerts, through its borings, a suction of the material, since it is connected to an air intake device. The marking means are constituted by a drilling or boring device of the material at several locations, preferably at its side edges out of the printing or dieing zone.And the retaining means are constitutes by groups of multiple small claws which are bevelled to help the feeding sense of the material to be printed, and located in an adjacent position to the respective conduit groups through which a suction is exerted, so that the material to be printed is permanently exposed to be introduced and being re-: tained by said small claws as soon as the drilled holes cut on the material by the marking device match with the claws.

In other possible embodiment, the driving means are diecs, part of which periphery has a different diameter, acting on the edges of the material to be printed out of the printing or dieing zone.

Likewise, it could be possible that at least one.of the printing rollers in each pair of roller would be fully cylindrical.

A better understanding of the, - system and. machine of the invention will be provided starting from the following description which is an example of a practical embodiment, with reference to accompanying drwKing8,in which: Figures 1 - 3 are schematic side views of an example of driving and printing rollers used in the system and machine of the invention.

Figure 4 is a side elevational view of the scheme of z printing machine according to the system of the invention.

Figure 5 is a schematic detail of an example of tensioning device of the material to be printed.

Figure 6 is a schematic detail of an example of retaining device of the material to be printed.

Figure 7 is a side elevational view of a printing machine according to the invention.

Figures 1 through 3 show schematically in an elevational view an example of driving and printing rollers usable according to the system of the invention. In these Figures, said rollers are designated with the general reference 10 and are arranged in pairs of same elements, said pairs being vertically aligned through their rotation axles 13. As it can be seen, each roller is the result of the bonding of two coaxial cylindrical portions having different diameter but of same height, the bonding being made in the sense of its generatrix. They could also be described as cy lindrical rollers fitted with a peripheral projection, also peripheral, under the general reference 11.

Between the pairs of rollers 10, the material to be printed 20 is drawn during the roller 10 rotation, varying the distance at which said material 20 will contact the projecting portions 11 of the rollers according to the relative initial position of said portions on each roller 10, the material 20 being free of contact when, at its rotation, the entering or of less. diameter portions 12. of each pair of rollers match.

In Figure 1, the contact travel between rollers 10 and material 20'will be maximal as for the illustrated.ax-ple, and-the traveiwill be lessee in the case of Figure 2, and therewis no contact between rollers 10 and material 20 in Figure 3.

The' control or adjustment of the relative position of each rol ler 10 in each pair is attained by rotating them about their res pective turning axis 13. In general, it will suffice to act on one only axis 13 in each pair to obtain the desired relative po station.

Referring to the scheme of Figure 4, it can be seen the presence of a series of pairs of rollers having the same characteristicc as the above-mentioned and designed under the general reference 10, but now they must be differentiated between printing rollers, with a relief or cliche-holder 30, for example for flexography, typography, offset or other printing systems, and driving rollers 40 for driving the material to be printed 20, which are preferably located at the exit of the machine (right hand of Figure).

Rollers 30 are provided with the corresponding relief or printing cloche (not shown), located at the greater diameter portion 11 of said rollers; for example, at the upper ones of each pair for printing the material 20 on a face, or in both of each pair in case of printing on both faces of the material 20.

The dimensions of the graphic motif to be printed on material 20 are known: and according to same the position of the driving and printing rollers (40, 30) will be adjusted. The driving rollers 40 will be adjusted specially for the longitudinal displacement required by the graphic motif, since their driving function does not essentially affect the transverse dimension of said graphic motif.

All rollers 30 and 40 are rotatory driven at the same speed, for example, with only one motor and driving means. Theorically, since the outer diameter of rollers 30, 40 is equal to their rotatory speed, the adjustment of the position of the respective rollers 30, 40 in each pair and the distance between consecutive pairs will imply that the graphic motif to be printed on the material 20 will arrIve at each pair of rollers 30, 40 in the adequate position to receive other color or graphic motif. Nevertheles, on multiple printings on continuous strip, there are flexural effects, resilience and sliding of material 20 between rollers 30,40, which effects are sufficient for altering the quality of the printing, for which reason it is necessary to dispose of a system assuring the arrival of, the material 20 at each pair or printing roller station 30 in the adequate position.

This can be obtained according to the work performed by the rollers 30, 40 when they take the before mentioned shape 10, 11, 12, combined with tensioning means 50, marking means 60 and retaining means 70, for the continuous strip of material to be printed 20.

It is to be understood that when rollers 30, 40 have completed their rotation with contact with the greater diameter parts 11, the, material 20 liberates from the rollers 30, 40, i.e., it is not subject to driving or dragging, and it stops until the moment that said parts 11 contact again with it . As previously mentioned, the resiliency, flexure and sliding between material 20 and rollers 30, 40 contribute to modify the printing quality.

To mitigate these defects of printing quality, it is first necessar to keep a tautness on the material 20 compensating for the strains peculiar to the resiliency and flexure of material 20 and to avoid a possible sliding between rollers 30, 40 during the driving or dragging of said material. Means 50 perform this tasks. Secondly, once this tautness has been obtained by means 50, it will necessary to mark the correct consecutive printing positions of material 20 under tension, this task being performed by the means 60. Lastly, there is a need for means -providing a material 20 retention in each correct determined position, until being driven or dragged towards a new printing station, the means 70 performing this operation.

The tensioning means 50 should be of a type allowing the material 20 to be fed under tension and maintain the material 20 tautness when this is driving free by rollers 30,40. Figure 5 shows details of an example of embodiment of such a means 50 by a hollow roller (51), which is drilled at its perphery and mounted with a turning possibility in a casing which is open at a zone corresponding to the contact sliding of the material to be printed 20 on said roller 51, which, during its turning, transmits, through its borings, a material suction 20, since it is connected, through its axle 53, to a suction device (not shown).The turning direction of roller 51 is reverse to the feeding oflmaterial 20, which, combined with the suction, impels the material 20 to slide under. resistance on said roller 51, so creating the desired stress which is adjusted by acting on the speed and suction. The sides of the open portion of the casing 52 act also as a transverse guide for the strip of material 20.

The marking means 60 of the correct or desired position of the material to be printed 20 are located, preferably, between the driving rollers 40 and are constituted by a drilling or boring device of the material 20. In the illustrated example (Figure 6), these means are an aligned and spaced pair of multiple drills 61 which will drill the material 20, preferably at its side edges, out of the printing zone.

The retaining means 70 will be constituted, preferably, by devices making use of the signals of the previous marking 60. For example (Figure 6), pairs of groups of multiple claws 71 which are revelled to favour the feeding sense of the material 20, located in a position adjacent to groups of orifices or conduits 72 through which a suction is created from a collecting cone 73, connected to a inlet device (not shown). In this way, the material 20 is permanently exposed to be introduced and remain held by small claws 71 as soon as these claws coincide with the drillings 62 cut on the material to be printed 20, in a previous position, by the marking device 60.

Starting from the described means and elements, the basic operation of a printing machine according to the system of the invention is as follows, with special reference to Figs. 4 and 7.

Once the machine has been fed with the material to be printed 20, the distances between printing roller stations 30 and between the marking device 60 and the retaining device 70 are to be adjusted. The material to be printed 20 is driven mainly by rollers 40, and in some. extent, by the printing rollers 30 turning, all them 30, 40,at the same speed and being adjusted in eaoh pair for a same position of their greater diameter parts 11: It is to be understood that the driving of the material 20 is only carried out during the time lasting the contact between said material and parts 11 of rollers,' and that the tensioning device 50 is kept rotating in a reverse sense to that of driving device 20, which overcomes the suction resistance of roller 51, and keeps under the adequate stress during the printing cycle.

As soon as the contact of parts 11 on the material 20 is finished, the material 20 stops and the tensioning device 50 tends to drive it in a reverse sense in its turning and suction, which does not happen when the material 20 is retained by the insertion of the small claws 71 into ~. groups of drillings 62 previously performed by the drills 61 (Fig. 6). Nevertheless, the material 20 is still taut by the action of device 50. While, rollers 30, 40 will go on turning and a few moments before their parts 11 contact again the material 20, the drills 61 will start to operate, so marking the correct position of material 20 at a time before starting the printing cycle on each of the consecutive stations or pair of rollers 30.The synchronism device between the rotation of the rollers and the marking operation has not been shown, and it can be performed, for example, by means of cams or any other means.

In this way, the material 20 is driven in succession towards the next station or printing roller pair 30, and it is released from its contact before arriving at said station, when the claws 71 are introduced into the drillings 62 cut during the marking of the preceding position, so impeding the material 20 to mave back, and defining with a great precision the position in wich the next printing rollers 30 will fall upon the material 20.

In fact, the drilling 62 surpass lightly the respective positions of claws 71, and the insertion of these claws into said drillings is carried out when the material to be printed 20 is lightly driven and taut inareverse sense by the device 50. Nevertheless, this little play or displacement tolerance, deliberately created upon adjusting the pairs of driving rollers 40, does not impair to determinate the correct position of the material 20, since the marking operation is performed at the moment said material 20 is retained by the clamps 71 and free of contact with rollers 30, 40, so that the distance between consecutive marked rollers is invariable.

Figure 7 shows with most detail an example of a machine according to the invention, wherein the pneumatic means 31, 41 with which the pairs of rollers 30, 40, are separated when a printing operation is finished or upon preparing a new one, are seen. In that position separated from rollers 30,40 by means of the adjusting controls 32, 42, the adjustment of the relative position located between pairs of rollers 30, 40 corresponding to the size of the click or graphic motif to be printed, is attained, with the help of a scale or similar indicator device located on the frame or bed of the machine, which also serves to fix the distance between the marking means 60 and the retaining means 70.

The printing stations or roller pairs 30 can be longitudinally displaced on guides 80; and when adjusted they will be spaced each other at a distance which will be a multiple of the longitudinal dimension of the click or graphic motif to be printed.

Once the machine is opera1;ing, it may be necessary.to carry out a fine adjustment of the longitudinal or transverse position of the pairs of rollers 30, which is attained by acting on the adjustment controls 32, 33.

The material to be printed 20 is supplied, for example, from a spool 81, creating the formation of a controlled loop 21, for example, by a photoelectric cell 22, in order to make easy the consecutive drivings of rollers 30, 40, and small reoveries of the tensioning device 50.

From the above description, it is assessed, in addition of the precision attained by a work of continuous, consecutive and multiple printing, the speed and simplicity of the present machine for each printing work and the easiness of placement of the printing rollers 30 according to different size of clinch8 or printing without the need for being replaced.

Also, the numerous variations and replacements through techni cal and equivalent means which can be introduced into a machine according to the invention are understable, in particular about its tensioning 50, marking 60 and retaining 70 devices. For example, the driving rollers 40 could be simple discs shaped in two diameters actuating on the edges of the material to be printed 20 on which the marking is caused, so avoiding every contact with the fresh printed surface of this material. Il would be also possible that the printing rollers 30 were fully cylindrical, the dragging of the material 20 being carried out only by driving rollers or discs 40, or only cylindrical the cliché holding roller.

Besides, and keeping the same principle of embodiment and performance of the invention, at the end of the series of printing rollers 30 or after the dragging rollers 40, dieing or cutting rollers of thé material 20 (not shown) could be incorporated.

Claims

1.- A continuous multiprinting system of the type wherein a strip of material to be printed moves along a series of printing stations on each of which the material to be printed is given in succession a color or graphic. motif, the system including: - driving means for the strip of material to be printed constituted by, at least, a pair of rotary rollers between which the material to be printed moves, the rollers of each pair being axially vertically aligned and each roller presenting a raised cylindrical portion and a recessed cylindrical portion , the relative position of each roller in each pair being adjustable so that the material to be printed is driven when it engages the respective raised portions of each rol ler,.and stops when, at the turning of each roller ,the recessed portions match;; - printing means of the strip of material to be printed constituted by one or more consecutive pairs of printing rollers between which the material to be printed moves, the rollers of each pair being axially vertically aligned and each roller presenting a raised cylindrical portion and a recessed cylindrical portion , the relative position of each roller in each pair being adjustable so that the material to be printed is given a printing when it engages the respective raised portions 11 of each roller , one of which, at least, is fitted with a relief or printing click, and it stops when, at the turning of each roller, the recessed portions match; - tensioning means for tensioning the material to be printed when it is driven along the printing stations, and maintaining taut the material to be printed when no drive is applied on it;; - marking means for marking the position of the material to be printed at a moment prior to starting to receive the printing on each of said stations, the material to be printed being stopped at said moment which corresponds to a coincidence position of the recessed portions of the driving rollers, and - retaining means 'for retaining the material to be printed in the marked position corresponding to the moment prior to starting to receive the printing on each of said stations.

2.- A system according to claim 1, in which the retaining means use physical signals effected by the marking means

3.- A system according to claims 1 and 2, in which the distance or gap between printing stations is adjustable.

4.- A system according to claims 1 to 3 in which the distance or gap between marking means and retaining means is adjustable.

5.- A system according to claims 1 to 4 in which the distance or gap between printing stations and between marking means and retaining means is adjustable according to the relative position chosen between eacn pair of driving rollers

6.- A system according to claims 1 to 5 in which besides pairs of driving rollers and printing rollers it includes pairs of dieing rollers.

7.- A system according to claims 1 to 6 in which the printing rollers are replaceable by dieing rollers.

8.- A continuous multiprinting machine of the type wherein a strip of material to be printed moves along a series of printing stations on each of which the material to be printed is given in succession a color or graphic motif, the machine including: - driving means forthe strip of material to be printed constituted by, at least, a pair of rotary rollers between which'the material to be printed moves, the rollers of each pair being axially vertical aligned, and each roller presenting a raised cylindrical portion ' and a recessed cylindrical por tion , thç relative position of each roller in each pair being adjustable so that the material to be printed is driven when it engages the respective raised portions of each rollers , and it stops when, at the turning of each roller- , the recessed portions match;; - printing means of the strip of material to be printed constituted by one or more consecutive'pairs of printing rollers between which the material to be printed moves, the rollers of each pair being axially vertically aligne, and each rollerpresenting a raised cylindrical portion and a rcesed cylindrical portion , the relative position of each roller in each pair being adjustable so that the material to be printed is given a printing When it engages the respective raised portions of each roller , of which one is, at least, fitted with a relief or printing click, and it stops when, at the turning 6f each roller , the recessed portions match;; - tensioning means for tensioning the material to be printed , working in opposition of the feed of said material when this is driven along the printing stations, and maintaining taut the material to be printed when it is not driven; - marking means for marking the position of the material to be printed at a moment prior to starting to receive a printing on each of said stations, the material to be printed being stopped at said moment which corresponds to a coincidence position of the recessed portions of the driving rollers , and - retaining means for retaining the material to be printed in the marked position corresponding to the moment prior to starting to receive the printing on each of said stations.

9.- A machine according to claim 8, in which the retaining means use physical signals effected by the marking means

10.- A machine according to claims 8 and 9 in which the distance or gap between printing station is adjustable.

11.- A machine according to claims 8 to 10 in which the distance or gap between marking means and retaining means is adjustable.

12.- A machine according to claims 8 to 11 in which the distance or gap between printing stations and marking means and retaining means is adjustable according the relative position chosen between each pair of driving rollers.

13.- A machine according to claims 8 to 12 in which, besides the pairs of driving rollers and printing rollers , it includes pairs of dieing rollers.

14.- A machine according to claims 8 to 13 in which the printing rollers are replaceable by dieing rollers.

15.- A machine, according to claims 8 to 14 in which the tensioning means are constituted by a hollow, drilled and rotary roller which rotates in opposition to the feed of the material , mounted on a casing which is open at the zone corresponding to the contacting sliding of the material to be printed on said roller , which, during its turning, exerts, through its borings, the suction of the material , since it is connected to a suction device.

16.- A machine, according to claims 8 to 15 in which the marking means are constituted by a drilling or boring device of the material at multiple points preferably at the side edges out of the printing or dieing zone.

17.- A machine. according to claims 8 to 16 in which the retaining means are constituted by groups of multiple claws , which are bevelled to make easy the feeding sense of the material , and are located in a position adjacent to the respective groups of conduits , through which a suction is exerted, so that the material is constantly exposed to be retained by said claws as soon as the boring cut on the material coincide with them, said borings being made by the marking device.

18.- A machine according to claims 8 to 17 in which the driving means are discs having a part of their periphery of different diameter, acting on the edges of the material to be printed , out of the printing or dieing zone.

19.- A machine according to claims 8 to 18 in which least one of the printing rollers in each pair of rollers is fully cylindrical.

20. A continuous multiprinting system substantially as described with reference to and as illustrated by the accompanying drawings.

21. A continuous multipringting machine substantially as described with reference to and as illustrated by the accompanying drawings.