EP0778131B1 - Sheet guiding system for a printing machine - Google Patents

Abstract

The paper guide system is fitted in the region of a passing-over drum (1). The drum is between paper guide cylinders (2,3) before and after it. The drum has partly or completely closed surfaces (5) between its grip rows (4). There is an air duct element (8) above the passing-over drum, with a small clearance from the motion track (7) of the grip rows. This element forms the upper boundary of the air space (9) extending from the front cylinder to the rear one. A fan (6) fills this space with air.

Description

The invention relates to a sheet guide system on a Printing machine according to the preamble of claim 1.

In sheet printing machines, the sheets of drums and Cylinders passed through the machine. The Front edge of a sheet from one row of grippers to the next passed on. For a good print quality is a clean one and flutter-free guidance of the sheets without smearing the printed area essential.

DE 43 42 203 A1 proposes a Sheet feeding system of the type mentioned at the outset to design that from the upstream cylinder to the Transfer drum delivered sheets by a blowing device from above, i.e. in the direction of the sheet transfer, with air is applied. In addition, a hot air squeegee is used Drying the sheets assigned to the upstream cylinder. After handing over a sheet to the subordinate Cylinder is the arrangement of further for guiding the bow Air knife proposed.

With the blowing device, which on the top down the required arc, there is a risk that the Air exposure in connection with gravity causes the bow to be pushed together. this happens especially with flexible substrates, with the result that bent and glued sheets are created. There this blowing device has only a slight drying effect has an additional hot air squeegee for drying intended. In addition, they are the downstream cylinder assigned air doctor blade required to have a good there too To ensure bow guidance. The extraction of air takes place in this sheet guiding system by means of a below the Bow guide cylinder arranged suction box instead. However, this can cause sliding friction between the sheet and the guide surface of the suction box, with the result that Scratches appear on the back of the sheet. This is special then disadvantageous if sheets are printed on both sides. The suction openings become when turning the transfer drum cyclically closed by the transfer drum, when the two gripper systems are horizontal face each other. In addition, the arch always covers the largest Part of the suction openings. As a result, no continuous Air flow. The moisture extracted from the bow accumulates in the air and remains within the Machine room. The air that is blown in is swirled with Moisture oversaturated and more randomly from the machine led out. Since there are no targeted material flows (air, Moisture, solvents, etc.) remain Drying result and sheet guiding of random factors dependent.

The described sheet guide system is also very complex and requires a high energy input.

The invention has for its object a simple designed sheet guiding system of the type mentioned to make available, in which through targeted material flows the sheet guide and - if drying between the printing units is provided - drying at reduced energy consumption is improved.

The object is achieved by the features of claim 1 solved.

The invention has the advantage that with little mechanical engineering the air of the aforementioned Blower is used several times. It serves first for Blowing of the cylinder guiding the downstream sheet passed bow, and after that this blowing air is in Steered towards the upstream bow-guiding cylinder, in order to achieve safe sheet guidance there too. In addition, the drag effect of the upstream bow-guiding cylinder used. After that, another part is used the blown air as carrier air for the guidance of the Conveyor drum conveyed sheet.

I. Einblasen von Luft und Verdichten der Luft oberhalb des Bogens.

II. öffnen der Lufteinlaßkammer und Aufrechterhalten des Druckniveaus durch Gleichgewichtsbildung zwischen eingeblasener und überströmender Luft.

III. Aufteilung der Luft in einen Abluftstrom, welcher zu den Abluftöffnungen hin entweicht sowie in einen innerhalb des Trommelraumes umgeführten Tragluftstrom.

IV. Umführen von Bogen mit Hilfe des stützenden Tragluftstromes im Trommelinneren und gleichzeitiges Herausdrängen des Abluftstromes infolge der Trommeldrehung.

The arrangement of the air guide element ensures that the transfer drum with its surfaces achieves an effect similar to that of a rotary piston and thus reinforces the air exposure. Here, the transfer process can be divided into four work cycles of air-assisted sheet guidance.

I. Blowing in air and compressing the air above the arch.

II. Open the air inlet chamber and maintain the pressure level by creating equilibrium between injected and overflowing air.

III. Division of the air into an exhaust air flow that escapes to the exhaust air openings and into a carrier air flow that is conducted inside the drum space.

IV. Redirecting bends with the help of the supporting air flow inside the drum and at the same time pushing out the exhaust air flow due to the rotation of the drum.

This allows a safe and good bow guidance on the upstream sheet-guiding cylinder, on the transfer drum and on the downstream arc-guiding cylinders can be reached. In addition, it is possible to dry sheets to achieve between two printing units in that the air blown to guide the sheet is heated and that a material flow from air from the work cycles mentioned, Moisture and dissolved constituents arise that over the arc constantly maintains a moisture gradient, which removes moisture from the bow and this over the Guiding air leads out of the machine while the sheet leaves the transfer area dry.

On the transfer drum, the sheets are so carried with air relined that flutter movements prevented or at least the vibrations are strongly damped. This will do so achieved that the surface of the transfer drum and the sheet form a closed chamber in which the air compresses becomes. Therefore, one always works in the area of the sheet guiding system Force on the printed side of the sheet, creating a secure sheet guidance is achieved.

In addition to these advantages, a Counterflow area on the upstream sheet-guiding cylinder arises, which, if necessary, has a high drying effect having. There is an outflow of moist air, and the drier air is used as the arc air, which for safe sheet guidance in the area of Transfer drum ensures and at the same time the sheet continues dries. With the handover of the sheet to the subordinate sheet-guiding cylinders are blown with fresh air and swirling of air and fresh air instead, which in turn achieves a high drying effect. The arrangement of the blowing device can only dry air can be drawn in from outside the machine. These advantageous effects are illustrated by the figures explained.

The blowing device is expediently arranged in such a way that they counter to the direction of sheet travel in the direction of subordinate bow-guiding cylinder blows. To this For this purpose it can be arranged on the air guiding element, it is further of advantage if they are concerned with their Alignment with the downstream sheet-guiding cylinder is adjustable. In this way, the blowing direction can be optimize depending on the printed fabrics. Of course, other arrangements of the Blow device conceivable. So you can also at the Arrange the transfer drum. In this case the blowing takes place in the machine cycle depending on the position of the Transfer drum instead.

A further improvement of the bow guidance in the area of Transfer drum can be achieved in that along the movement path of the gripper rows in the lower one Area of the transfer drum a sheet guide from upstream to downstream arc-guiding cylinder extends. This sheet guide can be closed or essentially closed baffle become. However, it is also possible to use the sheet guiding device to be provided with air inlet openings in this way to achieve a levitation of the bow. This allows a touch of the guiding surface of the sheet guiding device through the bow even with difficult to handle Exclude substrates with certainty.

An improvement in the bow guidance on the upstream sheet-guiding cylinder is achieved in that below of the air guiding element between the trajectory of the Rows of grippers and the upstream bow-guiding cylinder one oriented towards the latter Air guiding device is arranged. This can be done in parallel to the air-guiding sheet metal exist as Louvre grille or guide grille or as guide channels be trained. This makes it a non-vortex laminar Airflow is generated for a secure sheet support on the upstream sheet-guiding cylinder. Become the ends of horizontally running sheets of Air guiding device on the upstream bowing Cylinder-directed bends, so the Bow blowing further intensified. Such Angling can also be provided at the end of the air guiding element be what serves the same effect.

For a particularly intensive blowing of the bow on the upstream bow-guiding cylinder as well as for one intensive air conversion for drying can be provided that below the air guiding element between the trajectory of the Rows of grippers and the upstream bow-guiding cylinder an additional one oriented towards the latter Blowing device is arranged.

A further intensification of the blowing on the upstream sheet-guiding cylinder can be achieved in that the Air outlet opening is designed as an air outlet duct. The air for the blowing is compressed further and the Area of air pollution of the upstream bow-guiding cylinder further enlarged.

A dryer can be arranged in this air outlet duct, which intensifies the drying. He can be as Radiation dryer with ultraviolet or infrared radiation run or as a dryer, which with additional the air is blown dry, if necessary also warm air. Of course, you can also combine both combine.

It is important that the air space which the air control element closes at the top, is closed if possible. This can be provided that the distance from the drums and Cylinders to the side wall is as small as possible, or it can thereby achieving an improved closure of this room be that the transfer drum with side sealing washers Is provided. If necessary, additional Provide wall elements or elevations of the side walls, which with these side sealing washers a relatively tight seal form, which has only narrow gaps that for the Rotation of the parts are required.

Another possible implementation provides that the Air outlet and the air inlet for air circulation with each other are connected. However, sheet drying should also be achieved be, it is useful if between the air outlet and Air inlet Means for extracting air humidity are arranged. Such an arrangement should in particular when colors are processed which, in addition to moisture, are solvents contain which should not get into the work area.

The better removal of the moist and feed as possible dry air is a training that provides that an air inlet leading to the blowing device in the Printing machine enters and one of the air outlet opening downstream air outlet leads out of the printing press. The air inlet and the air outlet can, for example through openings in a tread plate, preferably in the form of Lattices to be formed. Such a step plate as it does between the printing units of a multi-color printing press is arranged, can also serve as an air guide to serve.

However, it can also be provided that the air outlet is not into the work area, but is discharged to the outside. The Possibility of such controlled elimination of the Exhaust air is due to the enclosed space created by the Device is formed possible. It is a Another great advantage of the invention, because in this way the health conditions of the work rooms improved and the exhaust air can be sent for cleaning.

In the case of sheet drying, it turns out to be special advantageous if the air blown in to guide the sheet is heated, or if the sheet guide by means of hot air he follows. The supply of hot air is also possible for this like heating the sheet air in the machine.

By using hot air to guide the sheet, the Sheet transfer area the function of a drying section take over, eliminating the use of an additional Drying plant, e.g. between two painting units can and a more compact design and thus can achieve associated cost savings.

The air guide can be attached to the hinge Fasten the machine in such a way that it faces upwards can be folded away. In this way the transfer drum is good accessible. This is for better maintenance and cleaning the machine.

The invention is described below with reference to the drawing explains which represents several embodiments and the function clarifies. For further advantages, Further training and other design options referred.

Fig. 1

ein Ausführungsbeispiel des Bogenführsystems,

Fig. 2 bis 5

das Bogenführsystem in vier Positionen anhand eines zweiten Ausführungsbeispiels,

Fig 6.

ein drittes Ausführungsbeispiel des Bogenführsystems,

Fig. 7

ein viertes Ausführungsbeispiel und

Fig. 8

ein Diagramm, das die Veränderung der relativen Feuchtigkeit in den Positionen der Fig. 8.2 bis 8.5
aufzeigt (diese entsprechen den Figuren 2 bis 5).

Show it:

Fig. 1

an embodiment of the sheet guide system,

2 to 5

the sheet guiding system in four positions based on a second embodiment,

Fig. 6.

a third embodiment of the sheet guide system,

Fig. 7

a fourth embodiment and

Fig. 8

a diagram showing the change in relative humidity in the positions of Figs. 8.2 to 8.5
shows (these correspond to Figures 2 to 5).

Fig. 1 shows a first embodiment of a Sheet guiding system for a printing machine. It is on one Transfer drum 1 arranged, which is between a upstream bow-guiding cylinder 2 and one subsequent arc-guiding cylinder 3 is located. In this Example is the sheet-guiding cylinders 2 and 3 µm impression cylinders. The transfer drum 1 can but also between other cylinders, for example painting cylinders or drums, which the Passing on bow serve. It is also the arrangement in a turning device conceivable. The bow-guiding cylinders 2 and 3 in the exemplary embodiment act as an impression cylinder together with rubber cylinders 24, the gap between the sheets 12, 12 ', 12' 'are printed on both cylinders.

The transfer drum 1 has two rows of grippers 4. The However, sheet guiding system is not on such Transfer drum 1 limited, it can also be three, four or there will be more rows of grippers 4. It is essential that between the rows of grippers 4 closed or in essentially closed areas 5 exist. These are required to have an effect similar to that of a rotary piston to achieve. The directions of rotation of cylinders 2, 3 and 24 and the transfer drum 1 are indicated by arrows 47. Above the transfer drum 1 is a Air guiding element 8, which is at a short distance from Movement path 7 of the gripper rows 4 is located. This distance must be such that in any case a collision-free movement of the transfer drum 1 guaranteed is. The air guide element 8 extends from upstream bow-guiding cylinder 2 to the downstream bow-guiding Cylinder 3, but not necessarily with any of these Cylinder 2 or 3 must complete, but itself for example up to one of the two rubber cylinders 24 can stretch up. It is essential that one of the upstream bow-guiding cylinder 2 to downstream arc-guiding cylinder 3 extending air space 9 arises, which is essentially of the cylinders 2, 3 of the Not drum 1, the air guide element 8 and others lateral walls shown is limited. This Airspace 9 should be essentially sealed with Exception of an air outlet opening 10, which is located on the upstream bow-guiding cylinder 2 facing end of Air guiding element 8 is located. The other end of the Air baffle 8 is in this embodiment of a blowing device 6 formed, which by means of a movable, tight connection 25 pivotable on the Air guiding element 8 is arranged. Through this swivel Arrangement of the blowing device 6, it is possible Adjust the blowing direction of the supplied air 34. This supplied air 34 is on an action area 27 of the subordinate arc-guiding cylinder 3 directed. she serves to ensure a smooth, flutter-free arch guidance on this To achieve cylinder 3. Essential for the air guide element 8 is that with the exception of the air outlet opening 10 Seals air space 9 upwards as well as possible, however the distances to the moving parts are observed need for a collision-free run are. The seal to the side can be made be that the air guide 8 as close to the Sidewalls protrude. Cylinders 2, 3 and 24 can also in that they protrude as far as possible on the side walls be sealed. The same applies to the transfer drum 1, it unless side sealing washers are arranged on this. Those can be designed such that they the movement path 7th correspond to the gripper rows 4 or are slightly larger. It is also possible that parts of the side walls, for example, those between the rotating parts lie, are raised and in this way for a provide even better sealing.

The sealing can also be done by additional lateral components such as plates, sheets, etc., on the Sidewall are attached to be performed.

In the embodiment shown in Fig. 1 is on the lower side of the transfer drum 1 a Sheet guiding device 11 arranged, which is such is located outside the movement path 7 of the gripper rows 4, that an arch 12, 12 ', 12' 'on it, if possible without touching it can be guided along. The sheet guiding device 11 can as a closed baffle or as a floating guide be trained. In the latter case it can be a Act nozzle plate, which ensures that the Arches 12, 12 ', 12' 'guided along an air cushion become. This embodiment is particularly then useful if sheets are to be printed on both sides and hence definitely touching the outside of the bow should be avoided.

In the illustrated embodiment is a Air guiding device 13 below the air guiding element 8 in the Area between the movement path 7 of the gripper rows 4 and arranged upstream of the arc-guiding cylinder 2. The Air guiding device 13 can, for example, be made parallel to Air guide element 8 lying sheets 14, which in Point in the direction of the upstream arc-guiding cylinder 2, to achieve a laminar airflow in this direction. Of course, further training courses are also conceivable, for example as guide channels, lamellar grids or standing guide vanes.

The air outlet opening 10 is preferably as an in Fig. 1 shown air outlet duct 18 formed essentially parallel to the surface of the upstream arc-guiding cylinder 2 against the direction of rotation 47 of Cylinder 2 extends. This air outlet duct 18 serves to create a jamming effect, the pressure of which is good Sheet guidance on the upstream sheet-guiding cylinder 2 has the consequence. The congestion effect arises from the fact that the the air outlet duct 18 exhaust air 33 with the Drag flow 37 of the upstream sheet leading Cylinder 2 meets. At the air outlet duct 18 can in addition, a dryer 19 may be arranged. It can be a radiation dryer acting in the direction of Bows 12, 12 ', 12' 'ultraviolet or infrared rays sends out, or it is also possible to use the dryer 19 Blown air, with warmed blown air or with radiation and To operate blowing air.

The is located in the entire area of the sheet guiding system freshly printed page 51 of sheet 12, 12 ', 12' 'in the area of blowing or air. This will ensure good leadership and Drying the sheet 12, 12 ', 12' 'between the printing nips 50 and 50 'achieved.

2 to 5 serve to explain the function of the Sheet guiding system, a second in these figures Embodiment is shown. It differs characterized in that the air guide element 8 has an angle 16 and the sheets 14 lying parallel to the air guiding element 8 Have bends 15. These bends 15 and 16 have such an angle α that they in essentially perpendicular to the surface of the upstream have arcuate cylinder 2. Have these bends the function of guide vanes or pressure increase blades and serve to apply air to the arches 12, 12 ', 12' ' the upstream bow-guiding cylinder 2.

Fig. 2 shows the work cycle designated I., in which the Transfer drum 1 in the position shown with the Blower 6, the rubber cylinder 24 and the subordinate arc-guiding cylinder 3 a Air inlet chamber 28 forms. The conclusion down takes place through the sheet 12 or if a sheet guiding device 11 is also provided by this instead. The blowing device 6 applies fresh air to this air inlet chamber 28 supplied, preferably drier and optionally heated air 34, the air flow to one Action area 27 of the downstream sheet-guiding Cylinder 3 is directed, on which an arc 12th located. The air flow is preferably contrary to that Direction of travel of the sheet 12 directed. In this Air inlet chamber 28 meet the supplied air 34 and the enclosed between the arch 12 and the surface 5 Arc air 35 on top of each other, with a swirl 36 takes place. The air becomes in the chamber volume compresses, resulting in high compressive forces on the sheet in Transfer area between the transfer drum 1 and the subordinate arc-guiding cylinder 3 and in the range up to to the pressure gap 50 result. This will be a good one Sheet support on cylinder 3 reached. Furthermore can by means of the mixed air a further drying of the Sheet 12 take place when it is fed Air 34 is dry and / or heated air.

Fig. 3 shows the transfer drum 1 in one position another turn, the one described above Work cycle II. In this position the Air inlet chamber 28 to an air outlet chamber 29 opened, whereby part of the air of the air inlet chamber 28th flows out towards the air outlet chamber 29. This outflowing air 49 is by means of the air guiding device 13 on an impact area 26 of the upstream sheet guiding Cylinder 2 passed to good guidance of the 12 '' arc. This bow 12 '' is on his Front edge also with a not shown in Fig. 3 Gripper row fixed and is to the rear by the Exhaust air 33, which flows out through the air outlet duct 18, stretched and pressed.

4, the transfer drum 1 has a further rotation completed and shows above that with III. designated Work cycle and shows below that after another 180 ° Rotation reached work cycle IV. The sheet 12 leaves the Air inlet chamber 28 in the direction of the pressure gap 50, and the supplied air 34 to the blowing device 6 and with it mixed sheet air 35 exits as outflowing air 49 the air inlet chamber 28 toward the air outlet chamber 29. A first partial flow forms in the air outlet chamber 29 31, which is a sheet air 35 between the sheet 12 '' and the drum 1 sets. A second partial flow 32 is through the Air guiding device 13 for blowing air still on the upstream arc-guiding cylinder 2 located Part of the arch 12 '' steered.

5 shows a further rotation of the transfer drum 1, through which the first partial flow 31 to form the Arch air 35 is reinforced. When training the first Sub-stream 31 and the second sub-stream 32 occurs advantageous air distribution because the drier air a has higher density and as the first partial flow 31 Arch air 35 forms. The moist air forms the second partial flow 32, which is the blowing of the arc 12 '' serves and is then discharged as exhaust air 33. Since the Bow 12 '' on the upstream bow-guiding cylinder 2 still has a lot of moisture, is the air of the second Partial stream 32 in spite of its moisture from the bow 12 '' in able to absorb more moisture. It is from great advantage that the air in relation to the movement of the Arc 12 '' forms a countercurrent area 44, whereby a high drying effect is achieved. After leaving the Air outlet duct 18 meets the exhaust air 33 Drag flow 37 of the upstream sheet leading Cylinder 2. The meeting again creates an increase in pressure and pressing the sheet 12 ''. After that the exhaust air 33 leaves the machine.

If there is a further rotation of the transfer drum 1, then a position occurs again, as already shown in FIG. 3 and 4 shown in the lower part and as work cycle IV was marked. The air of the first partial stream 31 is in a sheet support chamber 30, which by the Arc 12 'and the surface 5 is formed, in which it as Sheet air 35 for a safe guidance of the sheet 12 ' serves. A further drying of the sheet 12 ' achieved because it is mostly in the sheet air 35 the supply air 34 described above with high Dryness. The in the closed chamber 30 compressed air also has vibration damping effects on the bow, because this moves the compressed air during movements must press together. This stabilizes the bow, and contactless sheet travel is achieved. Through the Sheet guiding device 11 also remains the sheet support chamber 30 in the further rotation in the position shown in Fig. 4 the transfer drum 1 closed, whereby the carrying effect of compressed air remains and also the bow end is conducted safely.

6 shows a fourth embodiment of the Sheet guiding system. In this embodiment below the air guide element 8 between the movement path 7 the gripper rows 4 and the upstream bow-guiding Cylinder 2 an additional blowing device 17 is arranged. This blowing device 17 is in the direction of the sheet leading Cylinder 2 aligned and can, for example, from a Series of transversely arranged fans, which the Give an additional pressure increase to overflowing air. It can take the place of the air guiding device 13 or cooperating with such a sheet 12 'on the Blow upstream bow-guiding cylinder 2. By doing In the exemplary embodiment, the blowing device 17 acts in parallel to the air guiding plates 14 together, the one Bend 15 have. The air guide element 8 has also via such an angle 16. The exhaust air 33 flows through the air outlet duct 18, at which a Dryer 19 is arranged. The exhaust air 33 then arrives an air outlet 21 through openings 23 of the tread plate 22 is formed. The openings 23 are designed as grids. Furthermore, an air inlet 20 is provided in the tread plate 22, through the supplied air 34 to the blowing device 6. The air inlet 20 is also designed as a grid.

A further embodiment is conceivable in which the Air guide element 8 is formed by the tread plate 22, that is the air outlet 10 shown in Fig. 1 immediately in the tread plate 22 is provided and in this also the Blower device 6 is arranged.

Fig. 7 shows a fourth embodiment in which at least part of the air outlet opening 10 emerging air of the blower 6 is supplied to to produce a circulating air duct 38.

Fig. 8 shows a diagram showing the change in Moisture 41 of the sheet 12, 12 ', 12' 'and the relative Moisture 42 shows the air. In the horizontal is the handling of the path traversed by the sheet 12 and in the Vertical moisture applied, with Fig. 8.2 to 8.5 show the respective positions, which with those of Figures 2 to 5 match. Fig. 8.2 shows the Position after the delivery of a sheet 12 to the Transfer drum 1 (work cycle III.), In which the Air flows into a first partial flow 31 and a second Divide partial stream 32. There is an air exposure to the Arc 12 in countercurrent region 44 of Fig. 8, i.e. that the air flows against the sheet transport direction. Of the second partial stream 32 becomes exhaust air 33 after this blowing and the first partial flow 31 with less moisture Arch air 35. By blowing the bow 12 in Counterflow area 44 becomes despite the relative humidity 42 'drying the very wet sheet there with the Moisture 41 is achieved because of a sufficient moisture gradient is available. Then the sheet gets into the DC area 45, the work cycle IV. Which the Positions of Fig. 8.3 and 8.4 corresponds. The relative dry sheet air 35 with the relative humidity 42 In addition to its leadership effect, it ensures further drying of the sheet 12. After further rotation of the transfer drum 1 in 8.5 the air inlet chamber 28 is created (Work cycle I.), by which a fresh air admixture 43 by means of the supplied air 34, which thereby relative humidity 42 of the air is greatly reduced. Thereby their moisture absorption capacity increases again, and that Sheet 12 will be the remaining moisture until then withdrawn. The sheet 12 can now be dried Leave the transfer drum area and another pressure be fed. Another arch follows, arch 12 ', in the transfer drum area, which is the moisture 48, with which the course described again from the beginning begins.

The above description serves to explain the Invention and understanding of the function. The illustrated Exemplary embodiments are exemplary. Other combinations and configurations of the features mentioned are conceivable.

Reference list

1

Transfer drum

2nd

upstream bow-guiding cylinder

3rd

subordinate arc-guiding cylinder

4th

Rows of grippers (the transfer drum)

5

withdrawn closed or essentially closed areas

6

Blowing device

7

Path of movement of the gripper rows

8th

Air control element

9

airspace

10th

Air outlet opening

11

Sheet guiding device

12th

bow

12 '

bow

12 ''

bow

13

Air control device

14

Sheets lying parallel to the air guiding element

15

Bends

16

Bend

17th

additional blowing device

18th

Air outlet duct

19th

dryer

20th

Air intake

20th

Air intake

21

Air outlet

22

Step plate

23

openings (grid)

24th

Rubber cylinder

25th

flexible, tight connection (e.g. bellows)

26

Area of influence of the air on the upstream bow-guiding cylinder

27

Area of influence of the air on the downstream bow-guiding cylinder

28

Air inlet chamber

29

Air outlet chamber

30th

Arch support chamber

31

first partial flow

32

second partial flow

33

Exhaust air

34

supplied air

35

Bow air

36

Swirling

37

Drag flow of the upstream bowing Cylinders

38

Recirculation

39

UV or IR rays

40

humidity

41

Moisture of the bow

42

relative humidity of the air

42 '

relative humidity of the air

43

Fresh air admixture

44

Counterflow area

45

DC range

46

Mixing area

47

Direction of rotation

48

Moisture of the following sheet

49

outflowing air

50

Pressure gap

50

Pressure gap

51

printed side of the sheet

Claims (23)

1. Sheet guiding system on a printing machine, having a blowing device (6) and a transfer drum (1), which are located between an upstream (2) and a downstream sheet-conveying cylinder (3), the transfer drum (1) having closed or essentially closed surfaces (5) between its rows of grippers (4), characterized in that an air-guiding element (8) is arranged above the transfer drum (1) at a short distance from the movement path (7) of the rows of grippers (4) and bounds at the top an air space (9) that extends from the upstream (2) to the downstream sheet-conveying cylinder (3), and in that the blowing device (6) applies air to the air space (9) in the direction of the downstream sheet-conveying cylinder (3).
2. Sheet guiding system according to Claim 1, characterized in that an air outlet opening (10) is provided between the air-guiding element (8) and the upstream sheet-conveying cylinder (2).
3. Sheet guiding system according to Claim 1 or 2, characterized in that the blowing device (6) is arranged on the air-guiding element (8).
4. Sheet guiding system according to Claim 3, characterized in that the alignment of the blowing device (6) in relation to the downstream sheet-conveying cylinder (3) is adjustable.
5. Sheet guiding system according to one of the preceding claims, characterized in that the sheet-guiding air (34) that is blown in using the blowing device (6) is heated, for the purpose of achieving a better drying effect.
6. Sheet guiding system according to the preceding claims, characterized in that a sheet-guiding device (11) extends along the movement path (7) of the rows of grippers (4), in the lower region of the transfer drum (1), from the upstream (2) to the downstream sheet-conveying cylinder (3).
7. Sheet guiding system according to Claim 6, characterized in that the sheet-guiding device (11) is a closed guide plate.
8. Sheet guiding system according to Claim 6, characterized in that the sheet-guiding device (11) has air inlet openings to achieve floating guidance of the sheet (12, 12', 12'').
9. Sheet guiding system according to one of the preceding claims, characterized in that underneath the air-guiding element (8), between the movement path (7) of the rows of grippers (4) and the upstream sheet-conveying cylinder (2), there is arranged an air-guiding device (13) that is aligned in the direction of the said cylinder (2).
10. Sheet guiding system according to Claim 9, characterized in that the air-guiding device (13) comprises metal sheets (14) which are located parallel to the air-guiding element (8) and have at their ends bent-down sections (15) which are oriented towards the upstream sheet-conveying cylinder (2).
11. Sheet guiding system according to one of the preceding claims, characterized in that the air-guiding element (8) has at its end a bent-down section (15) which is oriented towards the upstream sheet-conveying cylinder (2).
12. Sheet guiding system according to one of the preceding claims, characterized in that the air-guiding device (13) is constructed as a lamellar grid.
13. Sheet guiding system according to one of the preceding claims, characterized in that underneath the air-guiding element (8), between the movement path (7) of the rows of grippers (4) and the upstream sheet-conveying cylinder (2), there is arranged an additional blowing device (17) that is aligned in the direction of the said cylinder (2).
14. Sheet guiding system according to one or more of Claims 2 to 13, characterized in that the air outlet opening (10) is constructed as an air outlet duct (18).
15. Sheet guiding system according to Claim 14, characterized in that a dryer (19) is arranged in the air outlet duct (18).
16. Sheet guiding system according to Claim 15, characterized in that the dryer (19) is a radiant dryer.
17. Sheet guiding system according to Claim 15 or 16, characterized in that the dryer (19) has a blower.
18. Sheet guiding system according to one of the preceding claims, characterized in that the transfer drum (1) has lateral sealing discs.
19. Sheet guiding system according to one of the preceding claims, characterized in that a foot plate (22) is arranged above the sheet guiding system.
20. Sheet guiding system according to Claim 19, characterized in that the foot plate (22) is at the same time the air-guiding element (8).
21. Sheet guiding system according to Claim 19 or 20, characterized in that an air inlet (20) leading to the blowing device (6) is provided in the form of an opening (23) that is made in the foot plate (22).
22. Sheet guiding system according to Claim 19, 20 or 21, characterized in that an air outlet (21) arranged downstream of the air outlet opening (10) is provided in the form of an opening (23) that is made in the foot plate (22).
23. Sheet guiding system according to one or more of Claims 2 to 22, characterized in that the air emerging from the air outlet opening (10) is fed to the blowing device (6).

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