EP0462490A1 - Film dampening system for a rotary press - Google Patents

Abstract

The invention relates to a film dampening system for rotary presses which comprises successively a dipper roller (101), which is driven at variable speeds by an electric motor, said dipper roller (101) being partially immersed in the wetting trough (107) which contains the dampening medium, a dosing roller (102) coated with elastomer, a dampening medium distributor roller (103) coated with hydrophilic material, and a forme dampening roller (104) coated with elastomer which is in contact with the dampening medium distributor roller (103) and the plate cylinder (105) of the press. …<??>The dampening system (100) according to the invention deserves consideration in that the dampening medium distributor roller (103) can be driven selectively by the dosing roller (102) in such a way that differential sliding takes place between the dampening medium distributor roller (103) and the forme dampening roller (104), or it can be driven by the plate cylinder (105) in such a way that the differential sliding takes place between the dampening medium distributor roller (103) and the dosing roller (102). As a result of the selective drive of the dampening medium distributor roller (103), the one or the other of the two different types of dampening can be applied optionally. …<IMAGE>…

Description

The present invention relates to printing technology and in particular to dampening devices for sheet-fed and rotary printing machines.

It is well known that the principle of operation of the rotary printing press is based on the fact that bold ink is repelled from a damp surface. For this reason, these printing machines are inevitably equipped with a moistening device, the main task of which is to distribute an even film of dampening solution onto the printing plate stretched around the plate cylinder. This film must be very thin (on the order of a micron) and also very uniform. The slightest non-uniformity would actually lead to a change in the optical density of the printing result (the uniformity of this density changes) and this results in a more or less visible error in the printing result. The aqueous solution used generally contains a certain number of additives, in particular to reduce the surface tension (with isopropyl alcohol) and / or to clean the plate (with citric acid).

There are a number of dampening devices that commonly equip sheetfed and rotary presses.

The humidifiers with a reciprocating lifter should be mentioned first.

The dampening devices of this type consist of a metal plunger roller, which is partly immersed in a fountain solution tank and which is driven by an independent electric motor at a slow speed, and of one A pair of rollers that rotates at the speed of the machine (at high speed), namely a chrome-plated metal roller, which is the dampening roller, and a rubber-coated dampening roller (which is usually coated with a coating), a kind of textile cover that acts as a reserve serves), which is in contact with the plate cylinder. Another roller, which is called a siphon roller, is arranged on a reciprocating contact bracket and thus alternately touches the dipping roller and the dampening roller, as a result of which the dampening solution film is transferred from one roller group to the other.

Such moistening devices are used less and less because they do not provide an evenly moist film and make it necessary to use a textile cover on the dampening roller, which quickly wears out and has to be replaced regularly.

Brush moistening devices are also worth mentioning, in which the dampening water is applied to the dampening roller by means of a round brush, the bristle tips of which dip into the dampening water tank and come into contact with firmly attached scrapers, which bend the bristles and produce the spraying of droplets on the dampening roller. In this way, the pair of rollers (namely the chrome-plated dampening roller and the rubber-coated dampening roller) that rotate at the speed of the machine are constantly supplied with dampening water. A variant of this device consists in that the round brush comes into contact with an immersion roller that is partially immersed in the solution and that the bristles produce a spray of drops.

Such devices, like the dampening water atomizing devices, by the way, are not real satisfactory because the film obtained is never completely regular and the spraying of droplets is rather unsafe.

In order to avoid the above-mentioned disadvantages of the moistening devices with reciprocating lifts or with brush moistening devices, film dampers are proposed.

In general, the film moisteners consist of two groups of rollers. A first roller group takes fountain water from the fountain box and rotates at a variable speed, which in any case is much lower than the speed of the machine (the plate arranged on the plate cylinder has a linear speed), this first group of rolls being arranged such that one of the rollers in this group is covered with an even film of moisture. A second group of rollers touches the plate arranged on the plate cylinder, rotates at the same linear speed as this and enables the fountain solution to be deposited on this plate.

The dampening solution is transferred between these two roller groups via a sliding contact. Indeed, all of the rollers are parallel to each other and touch each other along a surface line (or a transverse contact zone) such that the dampening solution film which is to be applied evenly to the plate is transported from one roller to the other, namely by the dip roller of the first group to the dampening roller of the second group.

• die beiden Walzen drehen sich im wesentlichen mit der gleichen linearen Geschwindigkeit, aufgrund eines konstanten Verhältnisses und können fest aneinander angestellt werden;
• die beiden Walzen drehen sich mit sehr unterschiedlichen linearen Geschwindigkeiten und berühren sind schwächer aneinander angestellt, um das relative Gleiten der Walzen zu gestatten.

Two cases can occur in the film moistening devices when two rollers touch along a surface line:

• the two rollers rotate at essentially the same linear speed, due to a constant ratio, and can be fixed against each other;
• the two rollers rotate at very different linear speeds and touch less strongly to allow the relative sliding of the rollers.

In general, the film moisteners available on the market today can be divided into two large groups: the emulsion moisteners with three rollers or the independent moisteners with four rollers.

The film emulsion moistening devices comprise three rollers arranged one after the other: an immersion roller which is coated with elastomer and is partially immersed, a chrome-plated metering roller and an ink or dampening roller coated with elastomer. The moisture film thickness on the metering roller is determined in this device by the passage of the dampening water between the elastomer-coated immersion roller and the chrome-plated metering roller, which are pressed together. A variable speed electric motor drives the plunger roller and the chrome-plated metering roller, which is connected to it via gears, while the inking roller is in contact with the plate cylinder plate and with the reciprocating inking roller which is in contact with the speed of the printing press turns. The dampening roller of the emulsion moistening device is thus the only one of the three rollers in said device which is driven at the speed of the machine, the sliding contact taking place directly on the surface of the dampening roller when it comes into contact with the metering roller. Film emulsion moisteners of the aforementioned type are known, for example, from French Patents No. 1,374,410, No. 1,547,536, No. 2,058,506, No. 2,196,249, No. 2,274,366 and No. 2,448,978.

These film emulsion dampening devices, to which Figure 1 of the accompanying drawings refers below, have the advantage of limiting the channel-related transfers by distributing the excess dampening water which remains on the dampening roller when passing through the channel of the plate due to the sliding contact with the metering roller. However, these humidifiers have the disadvantage that they work with a high proportion of isopropyl alcohol in order to reduce the surface tension (the water-color emulsion actually takes place before contact with the plate).

The independent film moisteners include four rollers arranged in series: a chrome plunge roller (or coated with a water-friendly material) that is partially submerged, an elastomer-coated metering roller, a chrome dampening roller (or coated with a water-friendly material) that moves back and forth, and a dampening roller coated with elastomer. In this moistening device, the wet film thickness is determined by the compression of the chrome dipping roller and the dosing roller coated with elastomer. The electric motor, like the emulsion moistening device, drives the dipping and metering rollers at variable speed, which is connected to it via gearwheels, while the dampening roller is driven at the speed of the printing press. The sliding contact takes place in this moistening device between the metering roller coated with elastomer and the chrome dampening roller (the strong pressure on the metering roller on the dampening roller is therefore deliberately set to "weak"). The dampening roller of the independent moistening device thus remains in contact with the dampening roller without slipping, and the sliding takes place on the surface of the dampening roller between said dampening roller and the metering roller.

Such independent film humidifiers of the type already mentioned are described, for example, in French Patents No. 1,491,977 and No. 2,211,348.

Such independent film moistening devices, to which Figures 2 and 3 of the accompanying drawings refer in the following, have the advantage that they use relatively low alcohol concentrations, in particular thanks to the reciprocating motion of the dampening roller, but they have the disadvantage of poor channel-related transmissions eliminate (the excess dampening water that remains on the dampening roller as it passes through the channel of the plate is actually squeezed out on contact between the roller and the dampening roller, but not leveled so that there is no sliding contact.

Each of the two film humidifiers mentioned above has advantages and disadvantages, and the user must initially select the humidifier to be used.

This is not so easy, as the printing form to be used and its area coverage as well as the deficiency to be remedied are not always definitive, so that it seems to be very interesting to be able to use one or the other type of humidification depending on the given circumstances .

Now, however, the known devices cannot be easily changed in order to switch from one embodiment to the other and are even not convertible for this purpose.

The object of the invention is to propose a combined convertible film moistening device which optionally comprises two types of moistening, namely emulsion moistening and moistening with four rollers, so that every situation can make the best use of the advantages of each device.

One of the objects of the invention is to provide a film moistening device which is easily convertible, i. that is, when switching from one mode of operation to the other, no lengthy and difficult dismantling and adjustment work is required.

Finally, the object of the invention is also to provide a combined and convertible moistening device which can be attached either to a sheet-fed or to a rotary printing press.

• eine Tauchwalze, die von einem Elektromotor mit veränderlicher Geschwindigkeit angetrieben wird, wobei diese uchwalze mit einem wasserfreundlichen Material beschichtet und zum Teil in den Feuchtwasserkasten eingetaucht ist, der das Feuchtwasser enthält;
• eine mit Elastomer beschichtete Dosierwalze, deren Drehgeschwindigkeit der der Tauchwalze entspricht;
• eine mit wasserfreundlichem Material beschichtete Feuchtreibwalze;
• eine mit Elastomer beschichtete Feuchtauftragwalze, die mit der Feuchtreibwalze und mit dem Plattenzylinder der Druckmaschine in Kontakt steht, wobei diese Befeuchtungseinrichtung dadurch gekennzeichet ist, daß die Feuchtreibwalze entweder von der Dosierwalzeangetrieben wird, derart, daß ein Differentialglieten zwischen der besagten Feuchtreibwalze und der Feuchtauftragswalze erzeugt wird, oder von einem Plattenzylinder angetrieben wird, derart, daß ein Differentialgleiten zwischen der besagten Feuchtreib- und der Dosierwalze stattfindet, derart, daß aufgrund des selektiven Antriebs der besagten Feuchtreibwalze auf die gleiche Weise benutzt werden kann.

It is in particular a film moistening device for rotary printing presses, which comprises in succession:

• an immersion roller which is driven by an electric motor with variable speed, said immersion roller being coated with a water-friendly material and partly immersed in the fountain solution tank which contains the fountain solution;
• a metering roller coated with elastomer, the rotation speed of which corresponds to that of the dipping roller;
• a dampening roller coated with water-friendly material;
• a dampening roller coated with elastomer, which is in contact with the dampening roller and with the plate cylinder of the printing machine, this dampening device being characterized in that the dampening roller is driven either by the metering roller, in such a way that differential smoothing is produced between said dampening roller and the dampening roller , or driven by a plate cylinder, such that differential sliding takes place between said dampening and metering rollers, such that, due to the selective driving of said dampening roller, can be used in the same way.

According to a first exemplary embodiment, the moistening device comprises a releasable coupling which connects the dampening roller either to the electric motor which drives the immersion and the metering roller or to the plate cylinder.

Advantageously, the shaft of the dampening roller carries a small first gear that meshes with the output shaft of the electric motor and a second small gear that meshes with the shaft of the plate cylinder, the releasable coupling rotating said shaft of the dampening roller with the first or the second small gear connects, the other small gear being movably provided on said shaft. The releasable clutch comprises in particular a disk which is arranged at each end of the shaft of the dampening roller, each disk abutting the first or the second gearwheel, the coupling between the respective disk and the respective gearwheel being effected by means of connecting bolts.

Preferably, the releasable clutch comprises a locking means which enables the dampening roller to be coupled to the electric motor and the plate cylinder at the same time prevented; the connecting bolts mentioned above are provided in a sufficient number for coupling a single disc to the gear in question in order to rule out a possible simultaneous coupling of the two discs.

According to an interesting variant, the moistening device comprises another variable speed electric motor which drives the dampening roller directly, this electric motor running either at the speed of the metering roller or at that of the plate cylinder. In particular, a tachogenerator, which is mounted on the shaft of the plate cylinder, and a speed sensor, which is connected to each of the electric motors, are provided, the drive motor of the dampening roller being equipped with an electronic control device, which is either from the speed sensor of the drive motor of the plunger roller or the signals coming to the tachogenerator of the plate cylinder.

According to another variant, the metering roller is also partially immersed in a dampening water tank and mechanical means are provided for displacing the shaft of the immersion roller, whereby the differential sliding either between the dampening and the dampening application roller when the immersion roller is started by the metering roller, or is generated between the dampening roller and the dosing roller when the dipping roller comes into contact with the dosing roller.

Preferably, the mechanical means that allow the shaft of the plunger roller to be displaced essentially consist of the contact brackets rotatably mounted on the frame of the printing press, which are arranged on both sides of the plunger roller, each contact bracket having a positioning means. In particular, the contact bracket rotate about an axis which is coaxial with the shaft of the Dosing roller runs, the positioning means being designed in the form of a toggle screw which extends through two bearings which are arranged on the respective shaft of the dipping or dosing roller.

Advantageously, the moistening device also includes an independent reciprocating mechanism, namely a worm gear connected to the dampening roller, such that the dampening roller is moved with a predetermined alternating reciprocating motion in either type of moistening.

According to another advantageous feature, the moistening device is supplemented by a bridge roller, which is arranged between the dampening roller and the closest inking roller, the bridge roller making contact between the dampening and inking rollers in one or the other type of dampening and also on the drive of the Dampening roller. In particular, the bridge roller is either arranged to be movable or is driven at the speed of the plate cylinder.

The bridge roller is advantageously arranged on the frame of the printing press with an eccentric device which makes it possible to establish or interrupt the contact between the bridge roller and the dampening roller.

Fig. 1

ist eine schematische Schnittansicht einer einer bekannten Emulsionsbefeuchtungseinrichtung mit drei Walzen,

Fig. 2

ist eine schematische Schnittansicht einer einer unabhängigen Filmbefeuchtungseinrichtung mit vier Walzen,

Fig. 3

zeigt einen vergrößerten Ausschnitt der das Problem des kanalbedingten Übertrags veranschaulicht, mit der Erhöhung, die von dem überschüssigen Feuchtwasser auf der Farb- bzw. Feuchtauftragwalze beim Passieren des Kanals der Platte gebildet wird.

Fig. 4

ist eine schematische Schnittansicht einer erfindungsgemäßen umstellbaren Befeuchtungseinrichtung,

Fig. 5

zeigt zum Teil eine Schnittansicht von Fig. 4, die gemäß Ebenen, die durch die Achsen der Walzen (Linie AA, BB, CC, DD der Fig. 4) gehen, entwickelt wurde; diese Schnittansicht läßt den Antriebselektromotor der Tauchwalze sowie die lösbare Kupplung (hier mit einer Scheiben-Zahnradanordnung, die man an jedem Ende der Welle der Feuchtreibwalze durch Verschraubung befestigen kann) sowie den sich hin- und herbewegenden Mechanismus der Feuchtreibwalze erkennen,

Fig. 6

ist eine Fig. 5 entsprechende Schnittansicht, die eine Variante aufweist, bei der die Feuchtreibwalze separat von einem zweiten Elektromotor angetrieben wird, der entweder mit der Geschwindigkeit der Tauchwalze oder mit der des Plattenzylinders umläuft,

Fig. 7

ist eine Fig. 4 entsprechende schematische Schnittansicht, die eine andere Variante der Erfindung aufweist, bei der auch die Dosierwalze zum Teil eingetaucht ist; die Tauchwalze kann von der Dosierwalze an- bzw. abgestellt werden, je nach dem welche Filmbefeuchtungsart man wählt.

Other features and advantages of the invention will appear more clearly in the following description and in the accompanying drawings, which relate to a specific embodiment with reference to the following figures:

Fig. 1

FIG. 2 is a schematic sectional view of a known emulsion dampening device with three rollers, FIG.

Fig. 2

Figure 3 is a schematic sectional view of an independent four roller film moistener.

Fig. 3

shows an enlarged section illustrating the problem of channel-related transfer, with the increase that is formed by the excess fountain solution on the ink or dampening roller when passing through the channel of the plate.

Fig. 4

is a schematic sectional view of a convertible humidifying device according to the invention,

Fig. 5

Figure 4 shows, in part, a sectional view of Figure 4 developed according to planes passing through the axes of the rolls (line AA, BB, CC, DD of Figure 4); this sectional view reveals the drive electric motor of the dipping roller and the releasable clutch (here with a disk gear arrangement which can be attached to each end of the shaft of the dampening roller by screwing) and the reciprocating mechanism of the dampening roller,

Fig. 6

5 is a sectional view corresponding to FIG. 5, which has a variant in which the dampening roller is driven separately by a second electric motor which rotates either at the speed of the dipping roller or at that of the plate cylinder,

Fig. 7

4 is a schematic sectional view corresponding to FIG. 4, showing another variant of the invention, in which the metering roller is also partially immersed; the dipping roller can be switched on or off by the metering roller, depending on the type of film dampening selected.

1 shows an emulsion moistening device 1 with three rollers.

As mentioned above, the film moistening device 1 comprises one another an elastomer-coated immersion roller 2, a chrome-plated metering roller 3 and an elastomer-coated inking or dampening application roller 4. The immersion roller 2 is partially immersed in the dampening water tank 7, which contains the dampening water 8 ; in addition, a constant water inflow (a tap 9) and an overflow (pipe 10) are provided, which keep the fountain water level in the water tank or in the fountain tank 7 constant. One of the rollers 2 and 3 (here it is the dipping roller 2) is driven by an electric motor 11 at variable speed by means of a belt 12 (or moreover by means of a cardan device, not shown here). The dipping roller 2 is in contact with the chrome-plated metering roller 3, these two rollers being connected to one another by intermeshing gearwheels 13, 14 (shown here in broken lines). Since the gears of the dipping roller 2 and the metering roller 3 mesh with one another, the speed of these two rollers is proportional (generally in a ratio of 1: 3).

The dampening roller 4 is in contact with the plate cylinder 5 on which the printing plate 6 is clamped. The inking roller 4 is also in contact with a reciprocating inking roller 15 which is driven at the speed of the machine, and this inking roller is in turn in contact with an inking roller 17 and an adjacent inking roller 16 (the first one) Group of three or four inking rollers), these latter rollers belonging to the inking unit of the offset rotary printing machine. The ink or dampening roller 4 is thus with the Speed of the printing press driven and the chrome-plated metering roller 3 is in turn driven by the electric motor 11; the ink or dampening roller 4 very lightly touches the chrome-plated metering roller 3, on which it slides and from which it removes a fine dampening film. In such a film moistening device, the passage of the fountain solution between the immersion roller 2 and the chrome roller 3, which are pressed against one another, determines the fountain solution film thickness present on the metering roller. In the specific case, the differential sliding zone 20 corresponds to the contact zone between the metering roller 3 and the inking or dampening roller 4 (the contact between the immersion roller 2 and the metering roller 3 is in turn either slip-free or with sliding in a fixed ratio, but without differential sliding takes place).

As mentioned above, this type of humidification has the advantage of limiting channel-related transmission. In fact, the plate cylinder 5 is provided with a channel 18 which enables the plate 6 to be clamped in such a way that excess dampening water remains on the inking or dampening roller 4 as it passes through the channel 18, but this error is made with the sliding contact 20 leveled between the metering roller 3 and the inking or dampening roller 4 due to the differential sliding between the rollers. As mentioned above, this type of humidification requires large amounts of isopropyl alcohol to function properly. This is due to the fact that the water-color emulsion takes place before contact with the printing plate 6.

FIG. 2 shows another known film moistening device, which is referred to below as an independent moistening device with four rollers.

Such a moistening device 50 comprises, in succession, an immersion roller 51 which is chrome-plated (or coated with a water-friendly material) and is partially immersed in a dampening water tank 57 containing the dampening water 58, a metering roller 52 coated with elastomer and a chrome-plated reciprocating dampening roller 53 (or coated with a water-friendly material) and an elastomer ink or dampening roller 54. As mentioned above, it is driven by an electric motor 61 with variable speed and by a belt 62; a device with a tap 59 and an overflow pipe 60 ensures an adequate level of dampening solution. The dipping roller 51 and the metering roller 52 work together via meshing gears 63, 64, as was the case with the first pair of rollers in the emulsion moistening device already mentioned.

However, the film thickness is determined by the compression between the chrome plunge roller 51 and the dosing roller 52 coated with elastomer. The ink or dampening roller 54 is - as in a previous example - with the plate cylinder 55 which carries the printing plate 56 and whose channel 68 can be seen. In such a moistening device, the dampening roller 53 is driven and moved back and forth; it is easily placed against the adjoining metering roller 52: the sliding contact (namely the differential sliding) takes place between the metering 52 and the dampening roller 53 in a zone 70. The dampening roller 54, which applies the dampening film to the pressure plate 56, lies between elements, which rotate at the speed of the printing press, that is, on the one hand between the plate 56 and on the other hand between the chromed dampening roller 53, in such a way that the excess water caused by the channel 68 of the plate is not eliminated or is not even partially leveled (in In contrast to the emulsion moistening device already mentioned, the contact between the wet friction roller 53 and the dampening application roller 54 takes place without slippage or with sliding in a fixed ratio and therefore shows no differential sliding).

Fig. 3 clearly shows the defect caused by the channel 68 of the plate: in fact in this figure one can see on the surface of the dampening roller 54 a part of the film 69 which has a single elevation 71 which corresponds to the transfer of the channel 68 Pressure plate 56 corresponds. This increase 71, which corresponds to an excess of water, which remains on the surface of the dampening roller 54 and is pressed together only on further contact with the dampening roller 53, without being leveled at this contact due to the lack of differential sliding.

2 and 3 also have a bridge roller 65 which is arranged between the dampening roller 54 and the first inking roller 66. This bridge roller 65 improves the operation of the moistening device 50; with certain printing forms, this moistening device works better than the emulsion moistening device 1. The bridge roller actually does the printing with alcohol substitutes instead of high-grade alcohol, by means of which the moistening device can be moved back and forth, which errors on the printed product can be eliminated, which are caused by local strips or Scratches on the dampening roller or the chrome roller.

As is apparent from the foregoing description relating to the known humidifiers, it is important to note that in the emulsion humidifier 1 in Fig. 1, only the ink or dampening roller 4 is moving at the speed of Printing machine rotates, and that the sliding with the other rollers takes place on their surface (differential sliding with the sliding contact 20), while with the independent dampening device 50, which is shown with four rollers in FIGS. 2 and 3, the inking or dampening application roller 54 remains in contact with the dampening roller 53 without slippage (or with sliding in a fixed ratio), these two elements being driven at the speed of the machine, and sliding with the other dampening rollers on the surface of the dampening roller 53 (with the sliding contact 70, this corresponds to the differential sliding zone between the metering 52 and the dampening roller 53). In the four-roller dampening device 50, the dampening unit also includes a reciprocating dampening roller 53, thereby reducing the dampening irregularities in the direction of the roll width.

A combined and convertible film moistening device according to the invention is described below, which optionally has two different operating modes, namely emulsion moistening and independent moistening with four rollers, so that the advantages of each moistening type can be optimally used for each special situation.

In Fig. 4 can be seen a film moistening device 100 which successively comprises a dip roller 101 partially immersed in a fountain solution box 107, which contains the fountain solution 108, the dip roller being driven by an electric motor with variable speed (not shown) and with a water-friendly material (z. B. a chromed outer surface) is coated, as well as a metering roller 102 coated with elastomer, the rotational speed of which corresponds to that of the dip roller 101, and one with a water-friendly material coated dampening roller 103 (e.g. chrome-plated on the outside) and an elastomer-coated dampening roller 104 which is in contact with the dampening roller 103 and with the plate cylinder 105 of the printing press. The dipping roller 101 and the metering roller 102 are connected to one another via intermeshing gear wheels 113, 114 in such a way that their speeds are proportional to one another. The dampening water tank 107 also includes a constant water inflow (faucet 109) and an overflow (pipe 110), which correspond to the elements described above.

Until then, the film moistening device 100 according to the invention behaves like a moistening device with four rollers, which is related to the known independent moistening devices which have already been mentioned in connection with FIGS. 2 and 3. Nevertheless, there is a significant difference between the dampening device 100 according to the invention and the independent dampening device 50 with four rollers, this difference being the way the dampening roller is driven.

In fact, according to a main feature of the invention, the dampening roller 103 of the moistening device 100 can either be driven selectively by the metering roller 102 such that differential sliding between the rollers, namely between the dampening and dampening application rollers 104 (by means of the sliding contact 120), takes place. or from the plate cylinder 105 such that differential sliding between the rollers, namely between the dampening roller 103 and the metering roller 102 (by a sliding contact 119) is produced, the selective drive of the dampening roller 103 in the same way either one or the other of the two different types of humidification.

When a selective drive is provided for the dampening roller 103 either via the metering roller 102 or via the plate cylinder 105, a combined and convertible film moistening device can be realized which optionally has two different types of moistening, namely an emulsion moistening or an independent moistening with four rollers.

A first embodiment of this selective coupling of the dampening roller 103, which is described below, is illustrated in FIG. 5.

The section through FIG. 5 shows the dipping roller 101, which is partially immersed in the fountain solution 107, the roller being driven by an electric motor 111 at a variable speed. For this purpose, the output shaft 126 of the electric motor 111 comprises a small gear 125, which meshes with another small gear 127, which is attached coaxially to the dip roller 101, but is coupled to the shaft 123 of the dip roller by means of cardan drives 124. The metering roller 102 in turn rotates around its shaft 128 which is attached to the frames of the printing press (frame 121 is often called the drive side and frame 122 the operator side). The gears 113 and 114 connect the dipping roller 101 to the metering roller 102. The chrome-plated dampening roller 103 is rotatably supported on the frames 121 and 122 by its shaft 141, a reciprocating device 155 being provided at one end of this shaft is described in more detail. The dampening roller 104 is in turn arranged by its shaft 147 on two contact brackets 148 and 149 which are rotatably mounted on the frames 121 and 122, respectively. The plate cylinder 105, which carries the pressure plate 106, is in turn rotatably supported by its shaft 151 on the frames 121 and 122.

The moistening device 100 in this case comprises a releasable coupling 150, via which the dampening roller 103 is either connected to the electric motor 111, which drives the immersion roller 101 and the metering roller 102, or to the plate cylinder 105.

In the specific case, the shaft 141 of the dampening roller 103 carries a first small gear 144 which meshes with the output shaft of the electric motor 111 (or more precisely, with the small gear 125 which is mounted on the output shaft 126 of the motor) and a second small gear 145, which meshes with the shaft 151 of the plate cylinder 105 (more precisely, with a gear 152 which is fixed with the shaft 151 of the plate cylinder 105, by means of a small intermediate gear 153 which is movably arranged on a pin 154 which is located on the operating side 122 located). The releasable clutch 150 enables the shaft 141 of the dampening roller 103 to either rotate together with the first gear 144, such that the second gear 145 is movably supported on the shaft 141, or with the second gear 145, such that the first gear is arranged on the shaft 141 just as movably.

There are, of course, several ways of realizing such a releasable clutch by using known toothed or friction clutches with an electrical, mechanical, pneumatic or hydraulic drive. A special embodiment of this releasable coupling is presented here, which is particularly simple and which also comprises a locking means which prevents the coupling of the dampening roller 103 with the electric motor 111 and with the plate cylinder 105 at the same time.

The releasable clutch 150 includes disks 142 and 143, respectively, on each end of the shaft 141 of the dampening roller 103 is stored; each disc 142 or 143 adjoins the first gear 144 or the second gear 145, and the coupling between the disc and the gear 142, 144 or 143, 145 in question takes place by means of stud bolts 146. It is found that here each Gear 144 and 145 is provided with a recess which receives the adjacent disc 142 and 143, which have holes with an internal thread, which firmly connect the disc to the gear by means of bolt screws 146. It goes without saying that if one changes from one type of dampening to the other, the printing machine is stopped, the bolts 146 are removed from the unit formed by the gear and the disk and on the other side of the printing machine in the gear-disk unit must be screwed on again.

When the releasable clutch 150 rotates the disk 142 with the first gear 144 (left side Fig. 5), the dampening roller 103 is driven directly by the metering roller 102, such that the differential sliding between rollers, namely between the dampening roller 103 and the dampening roller 104, the contact zone 120 is generated. This type of moistening therefore corresponds to the previously mentioned emulsion device, with the exception that it consists of four and not three rollers. However, when the stud bolts 146 are used to connect the washer 143 to the second gear 145 (right side FIG. 5), the gears 152 and 153 enable the shaft 141 of the dampening roller 103 to be connected to the shaft 151 of the plate cylinder 105 , such that the dampening roller 103 is driven directly by the plate cylinder 105, and the differential sliding between the rollers, namely between the dampening roller 103 and the metering roller 102 is produced according to a type of dampening of the independent four-roller device described above.

In addition, the releasable clutch 150, as described above, comprises a locking means which enables the dampening roller 103 to be coupled to the electric motor 111 and the plate cylinder 105 at the same time due to the just sufficient number of connecting bolts 146 required for the coupling of a single disc 142 and 143, respectively the relevant gear 144 or 145 are necessary prevented. In this way, any risk of the two disks 142, 143 coupling simultaneously can be excluded in a simple and reliable manner.

Thus, according to a very important feature of the invention, the film moistening device 100 comprises a dampening roller 103 (here a chrome-plated roller) which can be driven either at the speed of the printing machine or at the linear speed of the metering 102 and the immersion roller 101, as the user desires, which is supplied by an independent electric motor 111.

4, it can also be seen that a bridge roller 115 is arranged between the dampening roller 104 and the closest inking roller 116. In both the one and the other type of moistening mentioned above, the bridge roller 115 establishes contact between the dampening roller 104 and the first inking roller 116 and also participates in the drive of the dampening roller 104. Such a bridge roller is therefore advantageous in that it not only secures a bridge between water and paint in the traditional way, but also supports the drive of the dampening roller 104, thereby preventing excessive pressure between the dampening roller and the plate cylinder (because excessive pressure could actually squeeze the film). The plunger roller 101, which rotates in the direction of the arrow, transmits one Dampening solution film on the line of contact between the dip 101 and the metering roller 102; the metering roller distributes and limits the thickness of this liquid film by passing only a metered film between the two rollers which is much finer and more regular. In an emulsion moistening device, the bridge roller 115 proves to be particularly advantageous because it ensures a good drive for the dampening roller 104. In fact, the bridge roller 115 is in contact with the inking roller 116 and supports the drive in particular when passing through the channel 118 in the pressure line between the dampening roller 104 and the pressure plate 106.

As already mentioned above, a reciprocating mechanism 155 is also provided which is connected to the dampening roller 103; an exemplary embodiment is described in FIG. 5. One can actually see a reciprocating mechanism 155, which essentially comprises a worm wheel 156 and a worm 157, the worm of which is firmly connected to the shaft 141 of the dampening roller 103 and the worm wheel of which is provided with an eccentric device 160, which connects with the frame 122 via a connecting rod 159, which is movably mounted on the frame 122 at the pivot point 161. Such a worm gear is mounted on the movable housing 158 in such a way that the rotary movement of the dampening roller 103 alternately produces a forward and backward translation movement. Such a device can also be implemented by other appropriate means, which are usually known to those skilled in the art under the name of a reciprocating device. The purpose of this device is to give the dampening roller 103 an alternating back and forth movement of a small size (of approximately 8 mm) and with a frequency of 5 to 6 dampening roller revolutions in order to enable a forward and backward translation movement do. In practice, this frequency is determined by the worm gear. It should be noted here that the reciprocating mechanism 155 connected to the dampening roller 103 is designed to be used in the two types of humidification, since the adjacent releasable coupling 150 can engage regardless of the reciprocating mechanism .

5 shows the mechanical means 131 and 132 for setting the pressure force used between the metering roller 102 and the plunger roller 101. The adjustment means 131 thus comprises a contact bracket 129 which is rotatably mounted on the frame 121 of the printing press, said contact bracket being able to rotate about the axis 162 which runs coaxially with the shaft 128 of the metering roller 102. Two bearings 137, 138 are connected to the shaft 123 of the plunger roller 101 and the shaft 128 of the metering roller 102, respectively, and a screw spindle 133 with an operating lever 135 passes through these two bearings in such a way that that of the rotation of the lever in question Direction generated coupling and uncoupling of the bearings 137, 138 changes the contact pressure force between the two rollers in question. At the other end of this pair of rollers there is of course a symmetrical device, a mechanical means 132, which also comprises a contact bracket 130, which is rotatably mounted on the frame 122 of the printing press about the axis 163, which is coaxial with the shaft 128 of the metering roller 102 and a screw spindle 134 with an operating lever 136, which enables the engagement and disengagement of the bearings 139, 140, which are connected to the shaft 123 of the plunger roller 101 and to the shaft 128 of the metering roller 102.

The aforementioned bridge roller 115 cannot be seen in the sectional view of FIG. 5; the use of one such a roller is, however, in the independent moistening devices with four rollers, such as. B. the humidifier 50 described with reference to FIGS. 2 and 3, already known. This bridge roller 115 can be movably mounted or additionally driven at the speed of the plate cylinder 105. In addition, it is advantageous to arrange the bridge roller 115 on the frame of the printing press with an eccentric device which makes or breaks the contact between the bridge 115) and the dampening roller 104.

As already explained, the movement of the dampening roller 103 can either from the electric motor 111 via the gear wheels 125, 144, the bolt screws 146 and via the washer 142 or from the plate cylinder 105 via the gear wheel 152 and the gear wheels 145, 153, the same bolt screws 146 and generated over the washer 143 (on condition that this latter washer is connected to the gear 145 through the bolt screws 146). Depending on the circumstances, the dampening roller 103 rotates either at a linear speed generated by the motor 111 or at the linear speed generated by the printing press.

Two variants of the moistening device according to the invention are described below with reference to FIGS. 6 and 7, these variants comprising different means to implement the selective drive for the dampening roller 103 either over the metering roller or over the plate cylinder, always from the point of view of one Perform film humidification device that can be combined and converted at the same time.

6 shows a first variant 200 of the dampening device according to the invention, in which the dampening roller 103, now continuously with a second electric motor 171, is also driven at a variable speed, instead of the dampening roller 103 - with one or the other gearwheel - according to the wishes of the user connect to.

The film humidifier 200 comprises a large number of elements which the aforementioned film humidifier 100 has, and consequently need no further description.

In the film moistening device 200, the shaft 141 of the dampening roller 103 always includes a reciprocating mechanism 155, but no longer a releasable coupling 150, which was provided on both sides of the press frame. It is still possible to use the washer 142 and the first gear 144 which is connected to it by bolts 146, using these elements from the previous device (of course, this functional unit could be replaced by a single gear which is associated with the shaft of the dampening roller rotates).

On the output shaft 172 of the electric motor 171, a gear 173 is provided, which in this case meshes with the gear 144 of the dampening roller 103 such that it can drive the dampening roller 103 continuously. The electric motor 171 of the film moistening device 200 also runs either at the speed of the metering roller 102 or at that of the plate cylinder 105, as a result of which the dampening roller 103 can be driven either via the metering roller 102 or via the plate cylinder 105; this also applies to the film moistening device described above. So this enables selective drive of the dampening roller the optional use of one or the other type of moistening. Of course, the aforementioned speeds of metering roller 102 and plate cylinder 105 are linear speeds on the surface of these rollers.

The electric motor 171 preferably runs at the speed of the speed controller 176. The control circuit of the electric motor 171 can be oriented in such a way that a speed sensor 177 is connected to the electric motor 111, which drives the immersion 101 and the metering roller 102, another speed sensor 174 with is connected to the electric motor 171, which drives the dampening roller 103, and a tachometer generator 180 is connected to the plate cylinder 105. The speed controller 176 thus receives signals coming from the speed sensors 177, 174 via electrical connections 178 and 175, as well as signals coming from the tachometer generator 180 via an electrical connection 181. In addition, a switchover device 179 is provided at the input of the speed controller 176. When the switching element 179 is in the position which is indicated by a solid line, the speed controller 176 receives the signals from the speed sensor 174 and the tachometer generator 180, the speed of the motor 171 being adapted to the speed of the plate cylinder 105 (this is what is involved here) it is the independent type of humidification with four rollers); and when the switch 179 is in the dotted position, the speed controller 176 receives the signals from the speed sensors 174 and 177, the speed of the motor 171 being adapted to the speed of the metering roller 102 (this is the type of emulsion moistening).

In emulsion humidification, the voltage set point that determines the speed of motor 171 is determined by the Speed sensor 177 is supplied, which is driven by the motor 111 such that the motor 171 rotates at the speed proportional to the motor 111. In contrast, in the four roller independent dampening mode, the voltage setpoint supplied to the switch is generated by the tacho generator 180 connected to the printing machine (in this case the plate cylinder 105), consequently the motor 171 runs at a speed which corresponds to the printing press or is proportional to it.

This variant is interesting in that it enables a simple transition from one type of humidification to the other, by acting only on the switching element. However, it requires a second electric motor with variable speed.

7 shows another exemplary embodiment of a moistening device 300 according to the invention, in which the metering roller 102 - like the immersion roller 101 - is partially immersed in the wet box 107. The dampening device 300 thus formed comprises mechanical means for displacing the shaft of the immersion roller 101 in such a way that the differential sliding either between the dampening roller 103 and the dampening application roller 104 when the immersion roller is stopped by the metering roller 102, or between the dampening roller 103 and of the metering roller 102 is generated when the dipping roller comes into contact with the metering roller. In this other variant, attempts have been made to make use of the possibility of the transverse swiveling out of the immersion roller 101 relative to the adjacent metering roller 102, which is also partially immersed (such a shift is indicated in FIG. 7 by the arrow 190).

The mechanical means provided for displacing the shaft of the plunger roller 101 can be of various types; in front all the mechanical means 131 and 132 already described with reference to FIG. 5 can be used. However, in this case the mechanical means 131 and 132 have the task not only of regulating the contact pressure of the roller pair in question, but also of moving the plunger roller 101 between two working positions, namely from a first "parked" position, in which the Dip roller is parked by the metering roller, and in an "adjusted" position, in which the dip roller 101 is pressed strongly against the metering roller 102.

When the plunger roller 101 is stopped by the metering roller 102 by means of position adjusting members 133, 135 and 134, 136, the metering roller 102, which rotates in the direction of the arrow, transfers a thick film which, by passing between the dampening 103 and the metering roller 102, is dosed. In this mode of operation, which corresponds to the first working position of the plunger roller 101, the metering roller 102 and the dampening roller 103 rotate at approximately the same speed, while the dampening roller 104 continues to be driven at the speed of the printing press. The differential sliding takes place in the zone 120 between the dampening roller 104 and the dampening roller 103 and the distribution of the film takes place through these rollers, the contact force of which naturally decreases, so that the differential sliding can take place. This is a type of emulsion moistening.

However, when the operator acts on the position adjusting members 133, 135, 134, 136 such that the plunger roller 101 is strongly pressed against the metering roller, the dampening solution film thickness is determined by its passage between the dipping roller 101 and the metering roller 102, which is approximately the same Rotate speed, which speed is supplied by the drive electric motor 111. The film stretches when transferred to the dampening roller 103 which rotates at the speed of the printing press; and as it passes between the dampening 103 and dampening rollers 104, there is a simple transfer between rollers rotating at approximately the same speed. Differential sliding takes place in zone 119 between metering roller 102 and dampening roller 103. This is an independent type of humidification with four rollers.

The invention is not limited to the exemplary embodiments described above, on the contrary, it includes all variants which, in the form of equivalent means, have the essential features mentioned in the claims.

In particular, it is conceivable to replace the clutch mechanism of the dampening roller 103 either with a completely different type of positive or frictional clutch type or the like. Likewise, the floating independent worm gear could be replaced by another equivalent model, e.g. B. be replaced by a fast electromagnetic or a positive coupling.

Of course, the bridge roller 115 can be dispensed with in the film moistening device according to the invention in that - in one variant - the dampening roller 104 can be driven mechanically via a gearwheel which is connected to the printing machine (e.g. the plate cylinder) in such a way that for the Drive function does not require a bridge roller (such an arrangement could even cause vibrations that would affect the uniformity of the pressure). The advantages of the bridge roller 115 are still retained whether they are made of metal with an easily wettable color Surface (plastic or copper) or coated with elastomer. In general, this bridge roller is preferably provided with an eccentric device which establishes or interrupts the contact between itself and the dampening roller.

Other ancillary facilities such as B. the eccentric mechanism of the dampening roller, the metering roller or the bridge roller, and the adjustment devices of the rollers have not been described in this context. These traditional devices are used in all humidifiers currently in use.

REFERENCE SIGN LIST

1

Humidifier

2nd

Dipping roller

3rd

Dosing roller

4th

Ink / dampening roller

5

Plate cylinder

6

printing plate

7

Fountain box

8th

Fountain solution

9

water tap

10th

overflow

11

Electric motor

12

belt

13

gear

14

gear

15

Inking roller

16

Inking roller

17th

Ink distribution roller

18th

channel

20th

Differential sliding zone

50

Humidifier

51

Dipping roller

52

Dosing roller

53

Dampening roller

54

Ink / dampening roller

55

Plattenzlinder

56

printing plate

57

Fountain box

58

Fountain solution

59

water tap

60

overflow

61

Electric motor

62

belt

63

gear

64

gear

65

Bridge roller

66

Inking roller

68

channel

69

Movie

70

Sliding contact

71

increase

100

Humidifier

101

Dipping roller

102

Dosing roller

103

Dampening roller

104

Dampening roller

105

Plate cylinder

106

printing plate

107

Fountain box

108

Fountain solution

109

water tap

110

overflow

111

Electric motor

113

gear

114

gear

115

Bridge roller

116

Inking roller

118

channel

119

Sliding contact

120

Sliding contact

121

Frame (drive side)

122

Frame (operating side)

123

wave

124

Cardan drive

125

gear

127

gear

126

Output shaft

128

wave

129

Contact bracket

130

Contact bracket

131

mechanical means

132

mechanical means

133

Screw spindle

134

Screw spindle

135

Operating lever

136

Operating lever

137

warehouse

138

warehouse

139

warehouse

140

warehouse

141

wave

142

disc

143

disc

144

gear

145

gear

146

Bolts

147

wave

148

Contact bracket

149

Contact bracket

150

clutch

151

wave

152

gear

153

gear

154

Cones

155

floating mechanism

156

Worm wheel

157

slug

158

casing

159

connecting rod

160

eccentric facility

162

axis

163

axis

171

Electric motor

172

Output shaft

173

gear

174

Speed sensor

175

electrical connection

176

Speed controller

177

Speed sensor

178

electrical connection

179

Switching device

180

Tachometer generator

181

electrical connection

190

arrow

200

Humidifier

300

Humidifier

Claims (16)

Humidification device for a rotary printing press consisting of an immersion roller (101) which is driven by an electric motor (111) at variable speed, said immersion roller being coated with a water-friendly material and partially immersed in a dampening box (107) which contains the dampening solution, a metering roller (102) coated with elastomer, the rotational speed of which depends on that of the dipping roller (101), - a dampening roller (103) coated with water-friendly material, a dampening roller (104) coated with elastomer, which is in contact with the dampening roller (103) and with the plate cylinder (105) of the printing press, characterized by
that the dampening roller (103) can optionally be driven by the metering roller (102) such that differential sliding (between the rollers) takes place between the dampening roller (103) and the dampening roller (104), or by the plate cylinder (105) can be such that differential sliding (between the rollers) takes place between the dampening roller (103) and the metering roller (102), the selective drive of said dampening roller (103) likewise permitting both the one and the other type of dampening. Humidification device according to claim 1,
characterized by
that this comprises a releasable coupling (105) which connects the dampening roller (103) either to the electric motor (111) which drives the immersion roller (101) and the metering roller (102), or to the plate cylinder (105). Humidification device according to claim 2,
characterized by
that the shaft (141) of the dampening roller (103) has a first gear (144) which meshes with the output shaft of the electric motor (111) and a second gear (145) which meshes with the shaft (151) of the plate cylinder (105) , wherein the releasable coupling (150) connects the shaft of the dampening roller to the first gear (144) or the second gear (145) in a rotationally fixed manner, the other gear being movably mounted on the shaft. Humidification device according to claim 3,
characterized by
that the releasable clutch (150) comprises a disc (142, 143) disposed at each end of the shaft (141) of the dampening roller (103), each disc (142, 143) attached to the first and second gearwheels ( 144, 145), the coupling between the disk and the respective gear (142, 144 or 143, 145) being carried out by means of connecting bolts (146). Humidification device according to one of claims 2 to 4,
characterized by
that the releasable coupling (150) has a locking means which prevents the coupling of the dampening roller (103) with the electric motor (111) and the plate cylinder (105) at the same time. Humidification device according to claims 4 and 5,
characterized by
that the connecting bolts (146) are provided in just sufficient numbers to couple a single disc (142, 143) to the respective gear (144, 145) such that the two discs (142, 143) cannot be coupled at the same time . Humidification device according to claim 1,
characterized by
that it includes another variable speed electric motor (171) which drives the dampening roller (103) directly, this electric motor running either at the speed of the metering roller (102) or at that of the plate cylinder (105). Humidification device according to claim 7,
characterized by
that it includes a tachometer generator (180) mounted on the shaft (151) of the plate cylinder (105) and a speed sensor (177, 174) connected to each of the electric motors (111, 171), the drive motor (171) of the dampening roller (103) is equipped with an electronic control device which receives signals either from the speed sensor (177) of the drive motor (111) of the dip roller (101) or from the tachometer generator (180) of the plate cylinder (105). Humidification device according to claim 1,
characterized by
that the metering roller (102) is also partially immersed in a wet box (107), and that mechanical means (131, 132) are provided for displacing the shaft (123) of the immersion roller (101), the Differential sliding is generated either between the dampening roller (103) and the dampening roller (104) when the dipping roller (101) is stopped by the metering roller (102), or between the dampening roller (103) and the dosing roller (102) if the dipping roller is also the said metering roller is brought into contact. Humidification device according to claim 9,
characterized by
that the mechanical means (131, 132) which enable the shaft (123) of the plunger roller (101) to be displaced essentially comprise the contact brackets (129; 130) which are rotatably mounted on the frame of the printing press and are arranged on both sides of the plunger roller (101) each contact bracket (129, 130) has a position adjustment member (133, 135, 134, 136). Humidification device according to claim 10,
characterized by
that the contact brackets (129, 130) rotate about an axis (162, 163) which runs coaxially with the shaft of the metering roller (102), the adjusting element being designed in the form of a toggle screw (133, 135, 134, 136), which extends through two bearings which are arranged on the respective shaft (123, 128) of the immersion roller (101) and that of the metering roller (102). Humidification device according to one of claims 1 to 11,
characterized by
that it also includes an independent reciprocating mechanism (155), in particular a worm wheel (156) and a worm (157) connected to the dampening roller (103), such that the dampening roller (103) both at the one as well the other type of humidification is shifted with a predetermined back and forth movement. Humidification device according to one of claims 1 to 12,
characterized by
that this is supplemented by a bridge roller (115), which is arranged between the dampening roller (104) and the closest inking roller (116), with one or the other type of moistening the bridge roller (115) the contact between the dampening roller (104) and the inking roller (116) produces, and also participates in the drive of the dampening roller. Humidification device according to claim 13,
characterized by
that the bridge roller (115) is movably mounted. Humidification device according to claim 13,
characterized by
that the bridge roller (115) is driven at the speed of the plate cylinder (105). Humidification device according to one of claims 13 to 15,
characterized by
that the bridge roller (115) is mounted on the frame of the printing press with an eccentric device which makes it possible to establish or interrupt the contact between the bridge roller (115) and the dampening roller (104).

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