EP2835259B1 - Sheet guiding cylinder with a pneumatic sheet holding device - Google Patents

Description

The invention relates to a sheet guiding cylinder with at least one pneumatically controllable sheet holding device for a processing machine according to the preamble of independent claim 1.

A sheet guiding cylinder of this kind is made DE 43 35 185 A1 known, which is designed as a turning drum and having pneumatically controllable suction sheet holder means. The turning drum is known to be used for the application of sheets, in particular according to the principle of trailing edge. The suckers are in functional connection with a suction air line which leads via a control valve and the hollow axis of the turning drum to a vacuum generator arranged outside the hollow axle. The control valve can be mounted to oscillate in the body of the turning drum in a pivot point. At the control valve engages a pneumatically actuated, arranged on the side window of the sheet guiding cylinder working cylinder by means of a piston rod, which brings the control valve in the operating mode perfecting over a valve tappet with a roller with a control cam in engagement. The control cam is arranged on a control shaft and serves for suction air control in defined rotation angle ranges.

DE 43 15 548 A1 discloses a sheet guiding cylinder with a pneumatically controllable sheet holding means. A rotary valve is used from the outside, the suction air to a Mehrwegeabsperrschieber. The sheet guiding cylinder has in an embodiment two circumferentially arranged Sauggreiferreihen as sheet holding means, each Sauggreiferreihe having a separate rotary valve connection to the rotary valve. Lines from the rotary valve ports lead to the reusable gate valve and lines from the squeegee rows lead to the reusable gate valve.

Out DE 201 02 400 U1 and DE 103 50 726 A1 are further pneumatically controllable sheet holding devices for sheet guiding cylinder known. Also disclosed DE 40 12 498 C1 a drivable suction strip, which is coupled to a rocker shaft and can be driven by means of a cam gear.

From the DE 10 2011 084 210 A1 a sheet guiding cylinder with at least one pneumatically controllable sheet holding device is known. The sheet guiding cylinder has a suction strip with suction nozzles arranged at intervals and a compressed air source connected on the line side. Each suction nozzle is associated with an inlet opening adjacent, which is coupled to a flow channel with end arranged discharge opening. Each suction nozzle is coupled to an intake passage and the intake passage is merging into an opening in the flow passage. For rapid replacement of a sucked sheet of the suction nozzles is provided at sheet transfer, blow over a separate compressed air connection to the intake port or all the suction nozzles.

From the DE 10 2011 084 212 A1 are known a pre-gripper of a processing machine for sheet material. A pre-gripper with pneumatically controllable sheet holding device should be energy-efficient and operated with noticeably shortened control times. For this purpose, the pre-gripper is provided with a suction pad device with suction nozzles, inflow openings, flow channels and outflow openings. The inflow openings are coupled by means of connecting lines with an upstream manifold and a valve assembly upstream of the manifold. The valve assembly is coupled by means of a connecting line with a pneumatic source.

Suction nozzles of this type are prone to soiling like any other suction nozzle, which is due to the paper dust accumulating in the paper processing. If dirt enters the suction nozzles, it also reaches the area an ejector system and so can affect its function. However, in order to ensure an always sufficient and as even as possible holding force of all suction nozzles of a sheet-holding system and in particular to achieve an exact sheet transfer in the complex turning process, at least a perfect function of the suction nozzles must be ensured.

Therefore, from the DE 10 2009 014 632 A1 a device for supplying a vacuum consumer with negative pressure for the removal of dirt has become known. The device is provided in a sheet-processing machine, wherein from a vacuum generator, a suction line leads to the vacuum consumer, which is acted upon by negative pressure. Thus, a suction air flow leading from the vacuum consumer to the vacuum generator is generated. Between vacuum generator and vacuum consumers, a filter is arranged. Thus, a filter insert is provided in a suction nozzle, which prevents the entry of dirt, but even enforce relatively quickly and make the suction nozzle so unusable. To avoid this, the filter should be acted upon with blown air, transversely or oppositely to the flow direction of the suction air flow, to blow the filter free. The device obstructs the suction power of the suction nozzle, pollutes much faster than the suction nozzle itself and experience has shown that it is very expensive to clean with blown air, so that time-consuming cleaning cycles have to be activated.
If the cleaning cycles are integrated into the working cycle of a high-cycle frequency, effective cleaning of the filter is almost impossible. Cleaning the vacuum generator is not intended.

The invention is therefore based on the object to provide a sheet guiding cylinder of the type mentioned, the pneumatically controllable sheet holding device is safe to operate, the function of sufficient suction must always be ensured.

The problem is solved by the training features independent claim 1.

The pneumatically controllable sheet holding device has one or more suction bars with a plurality of suction nozzles arranged above the maximum format width of the sheet material. The suction nozzles are individually or in groups pneumatically controllable with respect to the air supply. The suction nozzles are arranged adjacent to the maximum format width of the sheet material at intervals adjacent and activated or deactivated individually or in groups. Taking into account the respective format width of the sheet material to be processed, optionally only the suction nozzles necessary for detecting an edge of the sheet material can be activated.
The suction strip has suction nozzles which are each formed in an ejector shape in the manner of a jet pump. By means of the suction nozzles is a fixing a Edge of the sheet material to be processed by suction of Ejektorsystemen feasible. Thus, in addition to the energy-efficient air supply, a noticeable increase in the suction force at the respective suction nozzle for the process-stable fixing of the edge of the sheet material can be realized.

According to the invention means are provided to blow the suction nozzles and preferably the Ejektorsysteme of contamination.

An arrangement of a closure element for covering the outflow opening of the ejector system in a rest position of the suction bar between two working cycles is advantageous.
A further advantage is the connection of a controllable blowing device to the intake passage.
A further advantage is the assignment of a controllable closure at the outflow opening of the ejector system.

Further developments emerge from the dependent claims.

Fig. 1

eine Bogenrotationsdruckmaschine mit einer Wendeeinrichtung,

Fig. 2

eine pneumatische Bogenhaltevorrichtung für eine Wendetrommel,

Fig. 2A

eine Ejektor-Einrichtung in vergrößerter Darstellung innerhalb der Bogenhaltevorrichtung,

Fig. 3

eine Bogenhaltevorrichtung mit Reinigungsfunktion,

Fig. 4A

eine Bogenhaltevorrichtung in Arbeitsfunktion, und

Fig. 4B

eine Bogenhaltevorrichtung mit einer Variante der Reinigungsfunktion.

The invention will be explained in more detail using an exemplary embodiment.
Here are shown schematically:

Fig. 1

a sheet-fed rotary printing press with a turning device,

Fig. 2

a pneumatic sheet holding device for a beater,

Fig. 2A

an ejector device in an enlarged representation within the sheet holding device,

Fig. 3

a sheet holding device with cleaning function,

Fig. 4A

a sheet holding device in work function, and

Fig. 4B

a sheet holding device with a variant of the cleaning function.

Fig. 1 shows as a processing machine a sheet-fed rotary printing press, with at least one printing unit I and at least one downstream in the conveying direction 5 of the sheet material 28 further printing unit II, each as an offset printing units with plate cylinder 1 (plate cylinder), blanket cylinder. 2 (Transfer cylinder), inking unit 3 and dampening unit 4 are provided. The blanket cylinder 2 is in operative connection with a sheet guiding cylinder 7, which is designed here as a counter-pressure cylinder. The sheet material 28 is supplied to the sheet guiding cylinder 7 of the printing unit I in the conveying direction 5, for example, by means of a sheet guiding cylinder 6.

Between the two printing units I, II a turning device III is arranged, which is intended for the fair and for perfecting and the sheet material 28 can evert under the principle of trailing edge application in the printing operation. Such a turning device III can be used as Eintrommelwendung or as in Fig. 1 be designed as a three-drum turn.
The turning device III after Fig. 1 In the conveying direction 5, the sheet guiding cylinder 8, a sheet guiding cylinder 9, here formed as a storage drum, downstream, has a bowing cylinder 7 of the printing unit I downstream in the conveying direction 5. This sheet guiding cylinder 9 is downstream of a turning drum 10 in the conveying direction 5.

The turning drum 10 follows the printing unit 11 and this printing unit II can be arranged downstream of the sheet transport in the direction of a sheet delivery, for example, a sheet guiding cylinder 6 or 8 for further sheet transport.
All sheet guiding cylinders 6 to 9 and the turning drum 10 have sheet holding means which are designed as grippers and / or suction grippers.
The turning drum 10 is twice as large in relation to the blanket cylinder 2 or plate cylinder 1, ie formed half-speed. It comprises on the circumference each two gripper systems arranged by 180 degrees and suction pads 12.

To FIG. 2 Each of the aforementioned suction bars 12 extends parallel to an axis 17 of the turning drum 10 over the maximum format width of the sheet material 28 and has a plurality of suction nozzles 20 for fixing a sheet edge, in particular the trailing edge 29, of the sheet material to be processed. The suction nozzles 20 are adjacent to the suction pads 12 in alignment over the maximum format width of the sheet material 28 at intervals arranged. Between these suction nozzles 20 free spaces 26 are arranged for dipping grippers of another gripper system.
Preferably, a respective suction bar 12 is used, which forms a profile body with all suction nozzles 20 and ejector systems.

Each suction bar 12 comprises per suction nozzle 20 an ejector system with inlet opening 21 for compressed air, which merges into a flow channel 23 with end-side outflow opening 24 and an intake duct 22 which merges into a flow passage 23 in an opening 25, wherein in the region of the junction 25 an ejector insert 40 is arranged (see Fig. 2A . 3 . 4A, 4B ).

All inlet openings 21 of a respective suction bar 12 are coupled by means of air lines 18 with its own, upstream manifold 13 for compressed air and a manifold 13 upstream, own valve assembly 14. Preferably, each valve assembly 14 with an upstream rotary feedthrough 15 and a rotary feedthrough 15 upstream compressed air source 16 may be coupled. The couplings are made by means of air ducts 18. The rotary feedthrough 15 is arranged on the axis 17 of the turning drum 10. The valve assembly 14 is coupled to a control device 19 signal and circuit technology and controllable such that each individual inlet opening 21 is supplied in each case with compressed air or the inlet openings 21 are each supplied in groups with compressed air. Here, the timing can be changed, so that the type of sheet material and the adjacent machine speeds in the control of the air supply to the suction nozzles 20 of the suction bar 12 can always be optimally taken into account.
In one embodiment, a switching valve of the valve arrangement 14 can thus each be in operative connection with a respective suction nozzle 20 of a suction strip 12. In a further embodiment, each one switching valve of the valve assembly 14 may be in operative connection with a group of suction nozzles 20 of a suction bar 12. Alternatively, a single switching valve of the valve assembly 14 with all the suction nozzles 20 a suction pad 12 be in operative connection.

In FIG. 2A Now, the core of an ejector system is shown in detail, wherein as the core element Ejektoreinsatz 40 is provided. The Ejektoreinsatz 40 is disposed within the flow channel 23 in the region of the junction 25 of the suction channel 22. The ejector insert 40 consists of a tubular element 41 whose cylindrical passage 41 A extends in the longitudinal direction of the flow channel 23. The tubular element 41 is provided at least in its central length region with circumferentially distributed openings (suction openings, bores) 42, which establish a connection between the outer wall of the tubular element 41 and the inner cylindrical passage 41A. The openings 42 are in FIG. 2 shown as check hatching. Number, size and shape of the openings can be selected according to physical conditions.
At an upper end region and at a lower end region of the ejector insert 40, an annular sealing element 43 and 44 is respectively arranged on the outside of the tubular element 41. By means of these sealing elements 43, 44, the ejector insert 40 is inserted coaxially in the flow channel 23.
A positioning of the Ejektoreinsatzes 40 within the flow channel 23 in the direction of the longitudinal axis of the tubular element 41 may be provided by stepped cylindrical paragraphs of different diameters in the flow channel 23 and corresponding to the Ejektoreinsatz 40.
By the annular sealing elements 43, 44, an annular space 45 is formed in the region between the sealing elements 43, 44 and between the tubular element 41 and the wall of the flow channel 23. In the annular space 45 of the intake duct 22 opens with its mouth region 25th
In the area of the air inlet 21, a fitting may be arranged separately or in connection with the ejector insert 40, at which the compressed air can be conducted into the ejector insert 40.

• In die Einströmöffnung 21 wird der Druckluftstrahl A eingeleitet
• Der Druckluftstrahl A wird mit relativ hohem Luftdruck durch den Durchlass 41A in dem Rohrelement 41 des Ejektoreinsatzes 40 geführt
• Wenn der Druckluftstrahl A die Öffnungen 42 im Rohrelement 41 passiert, wird aus den Öffnungen 42 Luft mitgerissen, so dass entsprechend an der Außenseite des Rohrelements 41 ein Unterdruck erzeugt wird.
• Der Unterdruck liegt im Ringraum 45 zwischen Rohrelement 41 und Strömungskanal 23 und Dichtringen 43, 44 an.
• Die dergestalt aus dem Ringraum 45 angesaugte Luft tritt danach zusammen mit der Druckluftstrahl A als kombinierter Luftstrahl D an der Ausströmöffnung 24 aus dem Strömungskanal 23 aus.
• Da die Ausbreitung des Unterdrucks durch die Dichtelemente 43, 44 in axialer Richtung des Ejektoreinsatzes 40 begrenzt wird, kann er sich nur in Richtung des Mündungsbereiches 25 des Ansaugkanals 22 fortpflanzen und generiert einen Ansaugstrahl B in dem Ansaugkanal 22.
• Unter Wirkung des Ansaugstrahls B wird Luft durch die hier nicht gezeigte Saugdüse 20 angesaugt, um Bogenmaterial festhalten zu können.

The function of the ejector insert 40 for generating negative pressure in an intake passage 22 and a suction nozzle 20 is as follows:

• In the inflow opening 21 of the compressed air jet A is introduced
• The compressed air jet A is guided at relatively high air pressure through the passage 41A in the tube element 41 of the ejector insert 40
• When the compressed air jet A passes through the openings 42 in the tubular element 41, air is entrained from the openings 42, so that a negative pressure is correspondingly generated on the outside of the tubular element 41.
• The negative pressure is in the annular space 45 between the pipe element 41 and the flow channel 23 and sealing rings 43, 44 at.
• The thus sucked in from the annular space 45 air then passes together with the compressed air jet A as a combined air jet D at the outflow opening 24 from the flow channel 23.
• Since the propagation of the negative pressure is limited by the sealing elements 43, 44 in the axial direction of the Ejektoreinsatzes 40, it can propagate only in the direction of the mouth region 25 of the intake passage 22 and generates a suction jet B in the intake passage 22nd
• Under the action of the suction jet B air is sucked through the suction nozzle 20, not shown here, to hold sheet material can.

The ejector insert 40 is in the Figures 3 . 4A and 4B each drawn at the appropriate place in abstracted form of representation. An ejector insert 40 is in Fig. 2 to provide correspondingly in each flow channel 23.

Fig. 3 shows a variant of the suction bar 12, which according to the embodiment according to Fig. 2 based. According to the variant, the already described intake duct 22 of a suction nozzle 20 is additionally coupled to a ventilation opening 30. The intake ducts 22 are coupled via the ventilation openings 30 in each case by means of air ducts 18 'to an upstream distributor 13' and to the distributor 13 'upstream valve arrangement 14' and this is coupled by means of an air duct 18 'via the rotary union 17 to the compressed air source 16. Manifold 13 and valve assembly 14 may optionally, in addition to the compressed air supply of the inlet openings 21 take over the air supply of the ventilation openings 30. The ventilation openings 30 can be acted upon by compressed air from the compressed air source 16 and support a quick detachment of the sheet material 28 of the suction nozzles 20, while the compressed air supply to the associated Inlet openings 21 may be temporarily interrupted. The compressed air is preferably fed as a pressure surge at the respective ventilation opening 30. At the turning drum 10, a respective suction bar 12 is formed drivable in a pivoting movement 27.

• Druckluft: Druckluftquelle 16 → Luftleitungen 18 → Drehdurchführung 15 → Luftleitungen → Ventilanordnung 14.
• Steuerungseinrichtung 19 reguliert Magnetventile der Ventilanordnung 14.
• Druckluft: → Ventilanordnung 14 → Luftleitungen 18 → Verteiler 13 → Luftleitungen 18 → vorgegebene Einströmöffnungen 21 (Ejektorsysteme).
• Druckluft: → Einströmöffnung 21 → Strömungskanal 23 → Ejektoreinsatz 40 (Ejektorsystem) → Luft ansaugen → Unterdruck an Saugdüse 20.

The effect is abstracted as follows (see also FIG. 4A ):

• Compressed air: Compressed air source 16 → Air lines 18 → Rotary union 15 → Air lines → Valve arrangement 14.
• Control device 19 regulates solenoid valves of the valve assembly 14.
• Compressed air: → Valve arrangement 14 → Air lines 18 → Distributor 13 → Air lines 18 → Specified inlet openings 21 (ejector systems).
• Compressed air: → inflow opening 21 → flow channel 23 → ejector insert 40 (ejector system) → suck in air → negative pressure at suction nozzle 20.

Of the control device 19 of the valve assembly 14 is predetermined, which applies suction nozzles 20 at the respective suction bar 12 with compressed air, i. activated or free of compressed air, d. H. should be disabled. Furthermore, the relatively short switching times are predetermined angle-correlated, so that the sheet edge can be recorded process-stable and released again. By individually taking into account the system times, switching times of the valve arrangement 14 are predetermined so that the boom detection process runs optimally.

The solution according to the invention is described below with reference to FIG. 3 . 4A and 4B described. According to the invention, it is intended to ensure the constantly optimal function of the ejector systems present on a suction strip 12.
As previously explained, the ejector systems consist of inlet opening 21, flow channel 23, inlet channel 22, ejector insert 40 and outlet opening 24 and are coupled to at least one suction nozzle 20.
For the purpose of securing the function of ejector systems and suction nozzles 20, a device for cleaning at least the suction channel 22 and the suction nozzles 20 of the ejector systems is provided.

To eliminate the contamination is provided to supply at least the suction nozzle 20 and the suction channel 22 against the direction of a suction B with compressed air. This compressed air supply takes place when the suction nozzles 20 are not closed with a sheet material 28.

According to FIG. 3 When the sheet material 28 has completely released the suction nozzle 20, a compressed-air pulse is introduced through the inlet opening 30 into the intake channel 22 via the air line 18 '. As a result, a storage area C is formed in the lower part of the intake duct 22 and a blow-out jet E is generated in the upper area of the extraction duct 22.
The blow jet E cleans the intake duct 22 and also the suction nozzle 20 and exits the suction nozzle 20 as a blow-off jet F.

In order to make the process of blowing more efficient, can be closed in the intake passage 22 in the area in front of the junction 25 by means of a controllable valve or a flap, so that the storage area C forms better and the discharge jet E is stronger.

A disadvantage of the solution FIG. 3 is that only the upper portion of the intake passage 22 and the suction nozzle 20 are blown out, whereas the Ejektoreinsatz 40 is rather even more contaminated with dirt.

In the FIGS. 4A and 4B is a further variant of the invention according to the device for cleaning the Ejektorsystems shown. This avoids the additional burden of the Ejektoreinsatzes 40 and ensures by means of cleaning air surges for cleaning and the ejector 40 all ejector systems.

In FIG. 4A the basic function of the suction bar 12 is shown in a position for detecting a sheet material 28 on the surface of a storage drum (sheet guiding cylinder 9). The suction bar 12 is tilted out of a basic position by means of a curved or swivel gear, so that the suction nozzles 20 are parallel to the surface of the storage drum indicated by dashed lines (Sheet guiding cylinder 9) lie there and can detect the sheet material 28 at its trailing edge 29.

The sheet material 28 is sucked by negative pressure by means of a suction jet B against the suction nozzle 20. The suction jet B is generated by the compressed air steel A at the junction 25 according to the Venturi principle. The compressed air jet A and the Suction B form together after the junction 25 the combined air jet D, which emerges from a corresponding outflow opening 24 of each ejector system 12 of the suction bar.

In FIG. 4B the second variant of the solution according to the invention is shown, wherein only a first embodiment is shown here.
By closing the outflow opening 24 of the ejector system with simultaneously applied air pressure at the inflow opening 21, a storage area C between the junction 25 and the outflow opening 24 is created. As a result, the compressed air of the compressed air jet A on the suction jet B (see Fig. 4A ) directed counter to the exhaust jet E through the suction channel 22 of the ejector system. As a result, there registered dirt can be blown out again and the suction nozzle 20 are made free again.

The general sealing of the outflow openings 24 on the suction bar 12 for all ejector systems contained can also be effected as a result of the movement of the suction bar 12. Here it is shown that the movement is carried out as a pivoting movement 27, as previously mentioned and in the FIGS. 4A and 4B is shown recognizable. In doing so, between the cyclical suction activities for gripping, holding and transporting the sheet materials 28 to be turned, the suction strip 12 always assumes a defined starting position, in which a functional break is provided. This starting position is in FIG. 4B documented. In this position, the outflow openings 24 of the ejector systems are positioned against a sealing stop 32 arranged on a cylinder wall 31 of the turning drum 10 and thus closed. The sealing stopper 32 may be more elastic and firmly positioned or he may be less elastic and in the Position to the suction bar 12 to be arranged adjustable. The sealing stopper 31 and is preferably made of an elastic material that can withstand load change in high cycle number.
Thus, the discharge openings 24 are closed once each movement cycle of the suction bar 12 by the sealing stop.

As a further variant, a closure of the outflow opening 24 by means of a closure element that is operated from the outside or by a controller. Instead of a fixed sealing stopper 31, therefore, the suction bar 12 may also be assigned a closure mechanism, in which a closing element 27 can be pressed or positioned against the outflow openings 24 as a result of the pivoting movement 27.
In addition, an adjustable closure element or a switchable valve can be provided on the outflow openings 24. Then, the outflow opening 24 can be closed controlled in a staggered to the working cycle of the respective suction nozzle 20 cleaning cycle.

As a further variant, a closure of the outflow opening 24 by an operator at a time outside the machine operation can be done manually way. This is preferably carried out in a maintenance cycle that is outside the operating time of the turning device. This results in the advantageous effect that no additional disturbing Luftverwirbelungen be entered in the field of sheet transport on the turning drum 10. It also reduces air consumption.

In the aforementioned functional break, cleaning blown air jets can also be automatically carried out by the compressed air suppliers. But it can also be done in all functional breaks each a Reinigungsblasluftstoß

1. [A] Einblasen von Reinigungsluft in eine Belüftungsöffnung 30 am Ansaugkanal 22 des Ejektorsystems zur Reinigung von Ansaugkanal 22 und Saugdüse 20..
2. [B] Einblasen von Reinigungsluft in Strömungskanal 23 einer Saugerleiste 12 (ohne Belüftungsöffnung am Ansaugkanal 22); Reinigungsluft wird bei geschlossener Ausströmöffnung 24 in Einströmöffnung 21 geblasen, so dass das gesamte Ejektorsystem gereinigt wird.

This results in the following possibilities for a cleaning method in which dirt is blown out of the intake duct 22 and the region of the suction nozzle 20 of a suction bar 12:

1. [A] blowing cleaning air into a ventilation opening 30 on the intake duct 22 of the ejector system for cleaning the intake duct 22 and suction nozzle 20 ..
2. [B] blowing of cleaning air in the flow channel 23 of a suction bar 12 (without ventilation opening on the intake passage 22); Cleaning air is blown in the inlet opening 21 when the outflow opening 24 is closed, so that the entire ejector system is cleaned.

• [A.1] Der Druckluftstoß zur Reinigung kann bei zugeschalteter oder bei abgeschalteter Druckluft an der Einströmöffnung 21 erfolgen.
• [A.2] Der Druckluftstoß zur Reinigung erfolgt, wobei die Verbindung zwischen Absaugkanal 22 und Strömungskanal 23 aktiv über ein Ventil im Reinigungstakt verschlossen wird.

For variant [A] variations are possible.

• [A.1] The compressed air surge for cleaning can be carried out at the inlet opening 21 when the compressed air is switched on or switched off.
• [A.2] The compressed air surge for cleaning takes place, the connection between the suction channel 22 and the flow channel 23 being actively closed by a valve in the cleaning cycle.

• [B.1] Der Verschluss der Ausströmöffnung 24 durch eine Bewegung der Saugerleiste 12 mit Anstellen der Ausströmöffnung 24 gegen einen Verschlusskörper (Dichtanschlag 32).
• [B.2] Der Verschluss der Ausströmöffnung 24 kann manuell durch den Bediener realisiert werden
• [B.3] Der Verschlusskörper kann zur Ausströmöffnung 24 hin bewegt werden, wenn gereinigt werden muss.
• [B.4] Die Ausströmöffnung 24 wird aktiv über ein Ventil verschlossen, wobei dieses Ventil die geforderten Schaltzeiten realisieren muss.

For variant [B] variations are possible.

• [B.1] The closure of the discharge opening 24 by a movement of the suction bar 12 with hiring the discharge opening 24 against a closure body (sealing stop 32).
• [B.2] The closure of the discharge opening 24 can be realized manually by the operator
• [B.3] The closure body can be moved towards the outflow opening 24 if it is necessary to clean it.
• [B.4] The discharge opening 24 is actively closed by a valve, whereby this valve must realize the required switching times.

The Blasluftstöße can be realized with the existing valve assemblies 14 and the existing control device 19. The Reinigungsblasluftstöße can be initiated cyclically or freely selectable.

Basic functions of the turning drum:

The turning drum 10 comprises at least one pivotable suction bar 12. By means of functional conversion of the turning drum 10, the sheet-fed printing machine can be operated either in straight printing or perfecting. In perfecting the turning drum 10 is operated in reverse pressure. In this case, a sheet material 28 at the rear edge by means of the suction nozzles 20 on the suction bar 12 of one of the turning drum 10 upstream sheet guiding cylinder 9 (three-drum turn) or an impression cylinder 7 (when Eintrommelwendung) and other grippers, the beater 10 is supplied.
Each sucker bar 12 is provided with suction nozzles 20 and ejector systems, which consist of inlet openings 21, flow channels 23, suction channels 22 and outflow openings 24, and formed from a profile body.
Each sucker bar 12 may be assigned its own manifold 13 and its own valve assembly 14, which are arranged on the turning drum 10. Each valve assembly 14 is coupled switching and signal technology with a control device 19.
Depending on a switching valve of the valve assembly 14 may be in operative connection with a respective suction nozzle 20 or with a group of suction nozzles 20 a suction bar 12. It may also be a switching valve of the valve assembly 14 with all suction nozzles 20 a suction bar 12 in operative connection.

LIST OF REFERENCE NUMBERS

1

- Printing forme cylinder

2

- blanket cylinder

3

- inking unit

4

- dampening unit

5

- Transport direction

6

- sheet guiding cylinder (transfer drum)

7

- sheet guiding cylinder (impression cylinder)

8th

- sheet guiding cylinder (transfer drum)

9

- sheet guiding cylinder (storage drum)

10

- beater

11

- Sheet guiding device

12

- Suction strip

13

- distributor (for compressed air)

14

- Valve arrangement

15

- rotary feedthrough

16

- compressed air source

17

- axis

18

- Air line (compressed air line)

19

- Control device

20

- Suction nozzle

21

- inflow opening

22

- intake duct

23

- Flow channel

24

- Outflow opening

25

- confluence

26

- Free space

27

- pivoting movement

28

- sheet material

29

- trailing edge

30

- Ventilation opening

31

- Cylinder wall

32

- Sealing stop

40

- ejector insert

41

- pipe element

41A

- passage

42

- Opening, suction opening, bore

43

- sealing element

44

- sealing element

45

- annulus

A

- compressed air jet

B

- Intake jet

C

- storage area

D

- combined air jet

e

- Blow-off jet

F

- Blowing jet

I

- Printing unit

II

- Printing unit

III

- Turning device

Claims (9)

1. A sheet guiding cylinder having at least one pneumatically controllable sheet holding device for a processing machine, comprising at least one suction cup strip (12) with suction nozzles (20) arranged spaced for fixing sheet material and a compressed-air source (16) connected on the line side,
   wherein each suction nozzle (20) of a suction cup strip (12) is coupled to an ejector system which is designed as consisting of an inflow opening (21) with a flow channel (23), an outflow opening (24) arranged on the same on the end side, a suction channel (22) which opens into the flow channel (23) at a mouth (25),
   wherein more or all inflow openings (21) are coupled to an air control system (13, 14, 19) and to a compressed-air source (16) generating compressed air,
   characterized in
   that in each ejector system within the flow channel (23) in the region of the mouth (25) of the suction channel (22) an ejector insert (40) generating a negative pressure through compressed air is provided,
   wherein the ejector insert (40) comprises a cylindrical passage (41A) which extends in longitudinal direction of the flow channel (23),
   in that means for generating a blowing air blast directed against the suction direction through the ejector systems and/or multiple or all suction nozzles (20) are provided,
   wherein the circumferential openings of the suction nozzles (20) are opened during the execution of the blowing air blast.
2. The sheet guiding cylinder according to claim 1,
   characterized in
   that means for generating a blowing air blast directed against the suction direction through the ejector systems and multiple or all suction nozzles (20) are provided.
3. The sheet guiding cylinder according to claim 1 or 2, characterized in that each suction cup strip (12) is arranged in a turning drum (10) and is arranged performing a pivot movement (27) for grasping and passing on sheet material (28) in turning mode in such a manner that the suction cup strip (12) following discharge of a first sheet material (28) and prior to accepting a following second sheet material (28) assumes a starting position, and in that a means acting in the starting position for diverting the compressed air is provided.
4. The sheet guiding cylinder according to claim 3,
   characterized in
   that on or in connection with the turning drum (10) one or more sealing elements assigned to all outflow openings (24) of all suction nozzles (20) of the suction cup strip (12) are arranged, wherein the sealing elements are arranged as acting in the starting position.
5. The sheet guiding cylinder according to claim 3 or 4,
   characterized in
   that on or in connection with the turning drum (10) a sealing stop (32) assigned to all outflow openings (24) of all suction nozzles (20) of the suction cup strip (12) is provided, wherein the sealing stop (32) is arranged sealing the outflow openings (24) of the suction cup strip (12) in the starting position.
6. The sheet guiding cylinder according to claim 3 or 4,
   characterized in
   that on or in connection with the turning drum (10) a controllable closure element assigned to all outflow openings (24) of all suction nozzles (20) of the suction cup strip (12) is provided, wherein the closure element is positionable in the starting position sealing against the outflow openings (24) of the suction cup strip (12).
7. The sheet guiding cylinder according to claim 3 or 4,
   characterized in
   that on or in connection with the turning drum (10) a manually operable closure element assigned to all outflow openings (24) of all suction nozzles (20) of the suction cup strip (12) is provided, wherein the closure element in the starting position is positionable sealing against the outflow openings (24) of the suction cup strip (12).
8. The sheet guiding cylinder according to claim 1,
   characterized in
   that on each suction cup strip to each ejector system a ventilation opening (30) is arranged on the suction channel (22) and in that to each ventilation opening (30) a compressed-air feed is provided, via which, by means of a valve arrangement (14, 14') that is controllable by a control device (19), compressed air can be directed into the suction channel (22).
9. The sheet guiding cylinder according to claim 8, characterized in that the valve arrangement (14, 14') is coupled to each suction nozzle (20) of the suction cup strip (12) in such a manner that when blowing air is directed into the suction channel (22) no blowing air is directed into the inflow opening (21), or in that a closure device is provided in the suction channel (22) which is located upstream of the mouth (25).

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