EP1136263B1 - Device for conveying a sheet for a rotary printing machine - Google Patents

Description

The invention relates to a device for transporting a sheet for a sheet-processing machine, in particular a Rotationsduckmaschine, in a processing direction with operatively rotating in a first direction first grippers for detecting the arc on an advancing in the processing direction gripper edge, a cylinder carrying the first gripper with a support surface formed on its circumference for the sheet gripped by the first gripper, operatively rotating in a second direction opposite to the first direction second grippers which take over the leading gripper edge from the first grippers and at least one pair operatively in the second direction around one Rotary axis of rotating arch supports, each having a concentric to the axis of rotation rolling surface whose extent along the axis of rotation is smaller than the width of a respective pressure-free side edge d bow and which presses the sheet within a respective side edge in areas of common normal of the support surface and the rolling surfaces to the support surface, as well as a machine equipped with the sheet processing machine, in particular a rotary printing press.

A device of the type mentioned is from the document JP SHO 55-18194 Y2 known and used according to this, to pass a printed sheet from a printing unit to a boom comprising an endless conveyor with arranged on rotating gripper jaws grippers, by means of which a leading gripper edge of the sheet detectable and the sheet after leaving the printing cylinder in itself left behind trailing edge of the sheet is weiterortransportierbar. However, this merely ensures that the sheet is forcibly guided on the pressure-free side edges thereof until its trailing edge passes through the regions of the common normal of the rolling surfaces and the support surface of the printing cylinder.

In order to guide the sheet also on its further path to a stacking station without smearing, it is particularly known to provide sheet guiding surfaces and to create between them and the sheet passed over flow conditions that hold the sheet in a certain flying height on the sheet guide surfaces.

As an alternative, it has also been proposed to lead the sheet after leaving a printing unit on a path to a stacking station by means of mutually phase-shifted peripheral leading edge gripper and trailing edge gripper (see DE 42 18 421 A1 ). To realize this, however, it is necessary to reliably detect a trailing gripper edge of the sheet by means of the trailing edge grippers. One solution to this is through DE 42 18 421 A1 but not suggested.

The German patent no. 627 851 is a proposal for realizing the detection of the trailing gripper edge by means of trailing edge grippers removed. According to this proposal, the sheet is taken by means of leading edge grippers of a printing cylinder and pulled by means of the leading edge gripper first chain drive over guide rails extending below the arch pulling down the bottom strand of the first chain drive along these strands. Below these strands a second chain drive is arranged, whose upper strands move in the same direction as the lower strands of the first chain drive. The second chain drive carries rear edge gripper, which should detect the trailing gripper edge when this gripper edge of the supported on the guide rail arc has reached a place where leave the upper strands of the second chain drive with respect to the direction of these Trume upstream deflecting. Although the trailing gripper edge of the sheet is prevented from descending below a predetermined level by means of the guide rails, it is not ensured that said gripper edge does not whip after running onto the guide rails. Apart from this, this concept is only suitable for Perfecting, and only if any markings occurring on the unprinted side of the sheet can be accepted by its loops on the guide rails, especially in a subsequent printing the back of the sheet in another pass unlikely to apply.

The US 2,757,610 shows a turning device with a storage drum and a downstream of this in the sheet transport direction turning drum. The turning drum has a gripper system for selectively gripping a sheet leading edge (straight printing operation) or sheet trailing edge (reverse printing operation).

The DE 3036790 shows a turning device with a storage drum, a storage drum upstream transfer drum and a storage drum downstream turning drum. The storage drum has grippers for detecting the sheet leading edge and suction pads for detecting the sheet trailing edge. In addition, the storage drum on a composite of segments Trommelkörpfer on which the sheet is transported.

The US 4,024,814 shows a turning device with a storage drum, this is a transfer drum upstream and downstream of a beater. The drum body of the storage drum has for sheet support on a plurality of axially arranged segments.

The invention has the object of providing the aforementioned device in such a way that a printed sheet is waiving abschmierfrei waiving fixed baffles.

To solve this problem, the device mentioned is equipped with operatively rotating in the second direction suction pads, which take over an applied by means of the arch supports to the support surface of the cylinder trailing gripper edge of the arc from the cylinder.

With the apparatus thus formed, the sheet grasped by the second grippers becomes first from the support surface of the first grippers peeled off the supporting cylinder, wherein a respective peeled-off portion of the arc extends from the second grippers to the common normal of the support surface and the rolling surfaces. In any case, the second grippers pass through a circular arc path when they have passed the said common normals. The pressure-free zones representing lateral edges of the peeled off from the support surface portion of the sheet are thus wound on the rolling surfaces of the arch supports. The bending forces exerted on the sheet by the first grippers cause these opposing reaction forces of the sheet to bias unexposed portions of the sheet towards the support surface of the cylinder. The invention makes use of this effect which leads to the fact that these reaction forces also press a trailing gripper edge of the sheet against the support surface, so that this gripper edge, when passing said common normals, rests in a straight line on the support surface and is therefore accessible to defined gripping means , These gripper means are designed with respect to the closed surface forming support surface of the cylinder as a suction pad. After the takeover of the trailing gripper edge by the suction gripper, the sheet is then stabilized at all its edges; he is thus a safe access of mechanically opening and closing grippers accessible especially at the trailing gripper edge, so that any further transport of the sheet under restraint of his leading and trailing gripper edge is possible.

According to the invention, a sheet guiding drum is provided which comprises the second grippers, the sheet supports and the suction grippers.

Such a sheet guide drum is used in a preferred use of the same in the case of a series construction of the rotary printing machine for transporting the sheet from a processing station, in particular a printing unit to the subsequent processing station, for example, another printing unit or a coating plant, etc., and it saves the conventional sheet transfer devices between the processing stations required, usually pneumatically supported sheet guiding devices.

A further development is characterized by a downstream of the sheet guiding drum, operatively rotating in the first direction transfer drum with third grippers, which take over the leading gripper edge of the second grippers, and with the third grippers lagging suckers, which take over the trailing gripper edge of the suction pads, and by an operatively encircling pregrippers and Nachgreifer comprehensive endless conveyor whose pregrippers take over the leading gripper edge of the third grippers and its Nachgreifer the trailing gripper edge of the suckers.

In this case, the transfer drum in a preferred embodiment of the same in the same manner as the sheet guide drum arch supports with concentric to the axis of rotation of the transfer drum Wälzflächen that press the sheet exclusively within the side edges of the sheet guiding drum in areas of common normal of the rolling surfaces on the one hand the sheet guiding drum and on the other the transfer drum.

In other particularly for the guide unilaterally or on envelope in a second pass through the rotary printing machine printed sheet suitable configuration, the transfer drum has a plurality of concentric to its axis of rotation surfaces, which follow each other in the axial direction of the transfer drum forming respective gaps. The intermediate spaces are dimensioned so that the suckers find in this place and in a preferred embodiment of the further allow a dipping of Nachgreifer in the same space by a sucker is arranged.

With the endless conveyor, the sheet is then under forced operation of his leading and trailing gripper edge especially in the direction of a stacking station of the rotary printing machine transportable, without the need for this conventional control devices for greasing-free sheet guiding.

The above-mentioned device in their inventive equipment with operatively rotating in the second direction suction pads, which apply a means of the arch supports to the support surface of the cylinder trailing gripper edge of the arc from the cylinder has in a preferred development on a operationally rotating endless conveyor on which to take over the leading gripper edge of the first grippers provided second gripper and trailing edge gripper includes, which take over the trailing gripper edge of the suction pads.

The case provided endless conveyor can be used in the manner described above for transporting the sheet in the direction of a stacking station and this the cylinder carrying the first gripper immediately downstream, said cylinder having a full area supporting the sheet support surface, as is the case in particular in a printing cylinder.

In a preferred embodiment of the endless conveyor immediately following the cylinder, its trailing edge grippers engage the trailing gripper edge in the outfeed gore between the support surface and the rolling surfaces. This allows measures by means of which the trailing edge grippers of the endless conveyor can pass the areas of common normal of the support surface of the cylinder and the rolling surfaces of the arch supports collision-free. The measures preferably provided for this purpose have in common that the trailing edge grippers pass through the cylinder within an envelope surface, which can be laid around the circulating suction grippers.

In a further preferred embodiment, it is provided that the mutual distance of the sheet supports is adjustable so that sheets can be processed with respect to the processing direction of different width.

A further preferred embodiment provides that the extension of the rolling surfaces in their circumferential direction is adjustable. Furthermore, it is preferably provided that the phase position of the suction pads and the phase position of the suckers is adjustable.

These measures allow the processing of sheets with respect to the processing direction of different lengths.

The invention is explained in more detail below with reference to drawings.

Figur 1

in schematischer Darstellung eine Bogen verarbeitende Maschine am Beispiel einer in Reihenbauweise ausgebildeten Rotationsdruckmaschine, die mit zeichnerisch nicht im Detail dargestellten Vorrichtungen zum Transport der Bogen ausgestattet ist,

Figur 2

in schematischer Darstellung ein Beispiel für die Anordnung von Druckwerkszylindern einer Bogen verarbeitenden Rotationsdruckmaschine in Reihenbauweise und von Transfervorrichtungen für die verarbeiteten Bogen,

Figuren 2a bis 2c

Schnitte entlang der Linie II in Fig. 2 bei unterschiedlichen Ausgestaltungen,

Figur 3

in schematischer Darstellung eine Transfervorrichtung zum Austrag der verarbeiteten Bogen aus einer Rotationsdruckmaschine,

Figur 4

eine schematische räumliche Darstellung einer der Konstellation von Fig. 3 entsprechenden Transfervorrichtung.

Hereby shows:

FIG. 1

a schematic representation of a sheet-processing machine using the example of a series construction rotary printing machine, which is equipped with devices not shown in detail for the transport of the sheet,

FIG. 2

a schematic representation of an example of the arrangement of printing cylinders of a sheet-fed rotary printing machine in a row construction and of transfer devices for the processed sheet,

FIGS. 2a to 2c

Cuts along the line II in Fig. 2 in different configurations,

FIG. 3

a schematic representation of a transfer device for discharging the processed sheet from a rotary printing press,

FIG. 4

a schematic spatial representation of the constellation of Fig. 3 corresponding transfer device.

In the Fig. 1 schematically illustrated sheet-processing rotary printing machine comprises a machine section 1 with by way of example two processing stations in the form of printing units 1.1 and 1.2, so that so that two colors can be printed. For each additional color another printing unit is provided. For further process steps, such as painting, intermediate drying, perforation, etc., a further processing station is to be provided in each case. In the case illustrated by way of example, the printing units 1.1 and 1.2 operate according to the wet offset method and accordingly each comprise an inking unit 1.3 and a dampening unit 1.4, a plate cylinder 1.5 in connection therewith, a blanket cylinder 1.6 operatively rolling on it and a printing cylinder 1.7 guiding a respective sheet.

For feeding the printing units 1.1 and 1.2 with a sheet feeder 2 is provided which picks up a respective top sheet 2.2 by a stack 2.3 by means of a separating device 2.1 and transfers to a transport and alignment device 2.4, which leading each in the processing direction leading to an imbricated formation isolated sheet according to which in particular by means of a Saugbändertisches done transport in the direction of front edge stops on these and at least one side stop aligns.

One of the first processing station, here the printing unit 1.1, associated oscillating pre-gripper 1.8 accepts the respectively aligned sheet 2.2 and transfers it to a feed drum 1.9 which in turn passes it to the printing cylinder 1.7 of the printing unit 1.1. After passing through the printing nip of this printing unit 1.1, the printing cylinder 1.7 transfers the sheet 2.2 to a transfer device in the form of a sheet guiding drum 1.10, which is connected between the printing cylinders 1.7 of the two printing units 1.1 and 1.2 and which is discussed in detail elsewhere becomes. The printing cylinder 1.7 of the printing unit 1.2 accepts the sheet from the sheet guide drum 1.10, leads him through the other printing gap and then passes it to a, explained in more detail elsewhere transfer device comprising a operatively revolving endless conveyor, which the respective sheet 2.2 to a stacking station 3.1 transported and releases there to form a Druckgutstapels.

In the continuous printing, the level of production at the stack 2.3 in the feeder 2, i. H. the height of the respective uppermost sheet 2.2, and in the stacking station 3.1, the drop height of the released sheet 2.2 by corresponding tracking respective stack 2.3 or the Druckgutstapel 3.2 supporting platforms 2.5 and 3.3 maintained by respective hoists, of which only the platforms 2.5 and 3.3 carrying lifting chains 2.6 and 3.4 are indicated.

In the Fig. 2 exemplary reproduced constellation of printing cylinders and transfer devices substantially corresponds to in Fig. 1 illustrated conditions and represents two successive printing units 1.1 'and 1.2' of a machine section 1 ', wherein one of the transfer devices, the sheet 2.2 transported from one to the other of the printing cylinder 1.7. This transfer device comprises operationally in a first direction in accordance with the direction arrow 1.11 circumferential first gripper 1.12 holding the machine section 1 'fed sheet 2.2 to a leading in the processing direction gripper edge 2.2 "of the same, and the first gripper 1.12 bearing cylinder, here the impression cylinder 1.7, which forms on the circumference of a support surface 1.13 for the part of the first gripper detected sheet 2.2 .. Furthermore, the transfer device operatively in a for first opposite second direction according to the direction arrow 1.11 'circumferential second gripper 1.14. These pass through the first grippers 1.12 and take over from them the leading gripper edge 2.2 "of the sheet 2.2 It is understood that the second grippers 1.14 are formed contrary to the simplified graphic representation by means of gripper fingers and similarly as these encircling gripper finger supports.

Furthermore, the transfer device comprises at least one pair - in the present embodiment with half-round rotating second grippers 1.14 according to Fig. 2 two pairs - in the second direction according to direction arrow 1.11 'about a rotation axis 1.15 rotating arches 1.16, each having a concentric to the rotation axis 1.15 rolling surface 1.17 whose extension along the axis of rotation 1.15 is smaller than the width of a respective non-pressure side edge of the sheet 2.2. A respective rolling surface 1.17 runs against the second grippers 1.14 and follows them.

The extent of the rolling surfaces 1.17 in the circumferential direction substantially corresponds to the extension of the largest possible processable with the rotary printing machine sheet in the processing direction. Moreover, the arch supports 1.16 are dimensioned and placed such that their rolling surfaces press a respective sheet 2.2 within its pressure-free side edges 2.2 'in areas of common normal of the rolling surfaces 1.17 and the support surface 1.13 to the latter while the leading gripper edge 2.2 "clamped holding second gripper 1.14 peel off the part 2.2 of the support surface 1.13 taken over by the first grippers 1.12 and wind it up on the rolling surfaces 1.17. Finally, the transfer device still operatively in the second direction according to directional arrow 1.11 'circumferential suction pads 1.18, which take a by means of the sheet supports 1.16 to the support surface 1.13 of the printing cylinder 1.7 applied trailing gripper edge 2.2'"of the sheet 2.2 from the impression cylinder 1.7 Suction openings that open into a lying around the rolling surfaces 1.17 of the arch supports 1.16 envelope surface and they hurry the second grippers 1.14 in such a phase position that they pass the pressure cylinder 1.7 at a time in their operational circulation in which these suction openings the trailing gripper edge 2.2 '"face.

The sheet 2.2 was already clamped at this time in the second gripper 1.14 and wound on the rolling surfaces 1.17 and from this time on the trailing gripper edge 2.2 '"of the sheet 2.2 is guided by means of the suction pads 1.18 additionally defined.

The transfer of the device ultimately intended transfer of such a stabilized sheet to the printing cylinder 1.7 of the printing unit 1.2 'then takes place in such a way that the first grippers 1.12 on the printing cylinder 1.7 of the printing unit 1.1' corresponding first gripper 1.12 of the subsequent printing cylinder 1.7, the sheet 2.2 of the take over second grippers 1.14. In that regard, the second gripper 1.14 represent the arch supports 1.16 and the suction pads 1.18 as components of the sheet guide drum 1.10.

In Fig. 3 is a preferred use of the bow guide drum 1.10 equivalent sheet guide drum 3.6 reproduced, which here a Component of a transfer device for discharging the example, in the printing units 1.1 and 1.2 or 1.1 'and 1.2' processed sheet 2.2 represents. The sheet guiding drum is in this case a last sheet-guiding cylinder, downstream of the printing cylinder 1.7 of the printing unit 1.2 or 1.2 'in the present examples, and cooperates therewith in the manner set out in connection with the sheet guiding drum 1.10.

The transfer device provided for discharging the processed sheets 2.2 further preferably comprises a transfer drum 3 .7 downstream of the sheet guiding drum 3. 1, operatively in the first direction (ie in the direction of rotation of the printing cylinder 1 .7), with third grippers 3. 8, which arrange the second one arranged here on the sheet guiding drum 3 Grapples 1.14 intermesh and pass from them the anticipatory gripper edge 2.2 '. On the transfer drum 3.7 further suckers 3.9 are arranged to take over the trailing gripper edge 2.2 '"of the sheet 2.2 of the arranged here at the sheet guide drum 3.6 suction pads 1.18.

To the transfer drum 3.7 is followed by an endless conveyor 3.5 ', the basic structure, apart from differences explained elsewhere, those of the endless conveyor 3.5 according to the FIGS. 1 and 2 equivalent. The endless conveyor 3.5 'comprises two chain pairs which are in each case operational in the second direction according to the directional arrow 1.11'. Each chain 3.10 of the chain pairs wraps around a deflecting body formed in particular in the form of a sprocket and one of four coaxial synchronously rotating sprockets 3.11, which are arranged in pairs at a mutual distance which is greater than that which can be processed in the largest possible in the machine section 1 or 1 ' bow present extent of the arc transverse to the processing direction. Between the chains 3.10 of a first of the two chain pairs, gripper bridges 3.12 supported by the chains 3.10 extend, on which pregrippers 3.13 for detecting the leading gripper edge 2.2 'are arranged. Between the chains 3.10 of a second of the two chain pairs, gripper bridges 3.14, carried by these chains 3.10, are arranged on which post grippers 3.15 for detecting the trailing gripper edge 2.2 '' are adjusted The phase positions of the pregrippers 3.13 and the Nachgreifer 3.15 are adjusted so that the pregrippers 3.13 assume the leading gripper edge 2.2 "of the sheet 2.2 of the third grippers 3.8 and the grippers 3.15 the trailing gripper edge 2.2 '" of the sheet 2.2 of the suckers 3.9.

In Fig. 4 are shown in a spatial representation and simplified a sheet guiding drum and a transfer drum, the one another and on the one hand with the pressure cylinder 1.7 according to Fig. 3 and on the other hand with the endless conveyor 3.5 'according to Fig. 3 in terms of Fig. 3 explained way, so that in Fig. 4 the components that those of Fig. 3 correspond, are provided with the same reference numerals as in Fig. 3 , even in the case of constructive deviations that are irrelevant to the function. The same applies to the reference numerals in the Figures 2 and 3 ,

The Fig. 4 clarifies in particular the Figures 2 and 3 non-removable details that serve to adapt the transfer device to different formats of the sheet 2.2.

An adaptation to the extent of each sheet 2.2 in the processing direction is done in the case of sheet guiding drum 3.6 as also the bow guide drum 1.10 (see Fig. 2 ) by setting a corresponding phase angle of the suction pads 1.18 to the second grippers 1.14, in the case of the transfer drum 3.7 by setting a corresponding phase angle of the suction 3.9 to the third grippers 3.8 and 3.5 'in the case of the endless conveyor by setting a corresponding phase position of the Nachgreifer 3.15 to Pre-grippers 3.13.

In the case of a provided with a drum shell transfer drum 3.7 according to the example of Figures 3 and 4 are provided for adjusting the phase position of the suction 3.9 in the drum shell surface circumferential grooves 3.16, along which the suckers 3.9 arranged therein are adjustable in a manner not shown. These circumferential grooves 3.16 have such a mutual distance, such a width and such a depth that arranged at a mutual distance along a respective gripper bridge 3.14 and take over the sheet 2.2 of the suction pads forming a suction 3.9 with these combing Nachgreifer 3.15 in this acquisition immerse each in the same circumferential groove in which a suction 3.9 is arranged. Said drum shell surface is preferably formed color repellent.

The pregrippers 3.13 and the Nachgreifer 3.15 are preferably biased in a known manner by spring force in the closing direction and are opened in a known manner on Rollenhebelanordnungen, which in turn are actuated by cams and, if necessary, with the pregrippers 3.13 or 3.15 with the Nachgreifern rotatably connected gripper shaft rotate in the sense of a gripper opening by a certain angle. The pre-gripper 3.13 and the Nachgreifer 3.15 go through in the embodiment according to Fig. 3 on one and the same surface lying tracks. However, this is not mandatory required. It is only essential that each of the two webs have common standards with an envelope drum enclosing the transfer drum 3.7 in the circumferential direction thereof and that, after gripping the trailing gripper edge 2.2 '' until a later release of the sheet 2.2, the distance of the pregripper leading to a bow 3.13 An impermissible change in the distance would be, in particular, such an enlargement of the distance that the sheet 2.2 is pulled out of the pregrippers 3.13 or the picking grippers 3.15 A permissible and preferably provided change in spacing exists, in particular, in a preferably temporary reduction of the distance Distance to the extent that the sheet 2.2 can form in a known manner a bead drawn into a nip of an unwinding device An intended unwinding device is preferably designed such that it excludes the gripper bars 3.12 and 3.14 A slack of the sheet 2.2 occurring in the region of a deflection of the endless conveyors 3.5 or 3.5 'is counteracted by means of blowing air.

In order to be able to transport sheets of different formats with the mentioned transfer devices, not only the components cooperating with the trailing gripper edge 2.2 '' are to be adjusted to their respective phase position relative to the grippers grasping the leading gripper edge, but also the sheet supports 1.16 are attached to the non-printing side edges 2.2 '. For this, the mutual distance of the pair of arch supports 1.16 effective in pairs on a sheet 2.2 can be adjusted.

Of the Fig. 4 is an example of a suitable design of the sheet guiding drum 3.6 removed, which in the same configuration, the Function of the sheet guiding drum 1.10 according to FIG Fig. 2 Fulfills.

The sheet guide drum 3.6 comprises a drum core 3.17, to which - here only schematically indicated - the second gripper are arranged 1.14, which are also biased in a known manner in a closing direction and are opened on roller lever assemblies and these actuated cams as needed. The drum core 3.17 is provided in the present example with T-slots 3.18 extending in the longitudinal direction of the sheet guide drum 3.6 and record correspondingly T-shaped, provided on the arch supports 1.16 feet, which are clamped by means of clamping screws 3.19 in the T-slots 3.18.

The drum core further has a recess 3.20, in which a suction device 3.21 with respect to the axis of rotation 3.22 of the sheet guiding drum 3.6 is arranged in a manner not shown pivotable and lockable. The suction device 3.21 forms a longitudinal direction of the sheet guiding drum 3.6, not shown, connected to a vacuum generator suction air duct 3.23. The suction grippers 1.18 have suction openings 1.18 'which communicate with the interior of the suction air shaft 3.23 and which open in the area between the sheet supports 1.16 into an enveloping surface spanned by the rolling surfaces 1.17. In the region of the present transversely to the processing direction extension of a sheet 2.2 with the smallest processed format, the suction pad 1.18 are preferably rigidly connected to the suction air shaft 2.23, while lying outside the smallest format suction pads 1.18 are so adjustable in the direction of the axis of rotation 3.22 out that a Adjustment of the arch supports 1.16 in the directions indicated by the double arrows 3.24 directions is possible to adjust the arch supports 1.16 on the pressure-free side edges 2.2 'of the sheet 2.2 can.

The rolling surfaces 1.17 of the sheet guide drums 3.6 and 1.10 provided sheet supports 1.16 are preferably formed on a non-illustrated elastic coating of the sheet supports 1.16, wherein the coating has a hardness which is preferably about 50 Shore. Thus, small changes in the thickness of the processed sheet 2.2 can be compensated. Alternatively, the rolling surfaces are 1.17 formed on corresponding unterlegbaren tread. This adaptation to larger differences in thickness of the sheet 2.2 is possible. In the case of the processing of sheet 2.2 with noticeably different thicknesses, for example, the axis of rotation 3.22 of the sheet guiding drum 3.6 in the sense of the double arrow 3.25 (see FIG. 4 ) displaceable in order to press the rolling surfaces 1.17 under a sufficient pressing force against the side edges 2.2 'of the sheet 2.2 resting on the support surface 1.13.

While in the so far explained transfer device (according to the Figures 3 and 4 ) for the discharge of the sheet 2.2 these are transferred indirectly from the last processing station to an endless conveyor (here the endless conveyor 3.5 '), in another embodiment, an in Fig. 2 illustrated transfer device for discharging the sheet 2.2 is provided, in which the sheets are transferred from the last processing station (here the printing unit 1.2 ') to an endless conveyor 3.5, which passes directly through the last processing station. This endless conveyor is constructed analogously to the already described endless conveyor 3.5 'and also includes two operatively in the second direction according to direction arrow 1.11' circulating chain pairs. each Chain 3.10 'of the chain pairs wraps around one of four operatively synchronously rotating same sprockets 3.11', which are analogous to the endless conveyor 3.5 'spaced apart and have a common axis of rotation 3.26. A first of these pairs of chains carries gripper bars 3.27, to which the second gripper designated here for the assumption of the leading gripper edge 2.2 'of the first grippers 1.12, here designated by 1.14' are arranged.

As in the case of the bow guide drums 1.10 and 3.6 are arch supports 1.16 'are provided which rotate in the present case together with the sprockets 3.11' to the axis of rotation 3.26 of the sprockets 3.11 'concentric rolling surfaces 1.17 form and the side edges 2.2' of the sheet 2.2 to the support surface 1.13 of the printing cylinder 1.7 of the printing unit 1.2 'press during the part of the second gripper 1.14' detected sheet 2.2 peeled off from the support surface 1.13 and is wound onto the rolling surfaces 1.17. The arch supports 1.16 'in turn follow the second grippers 1.14 and close to this after a gripper bar 3.27 it is immersed in the orbit of the rolling surfaces 1.17 and together with the arch supports 1.16' circulates on a circular path to the gripper 3.27 supporting chain pair the corresponding pair of sprockets 3.11 'leaves.

In contrast to the arch supports 1.16 of the sheet guiding drum 1.10 and 3.6, the extension of the arch supports 1.16 'in the circumferential direction thereof is adjustable, namely to adapt to different extents of the processed sheet 2.2 in the processing direction. For this purpose, a respective sheet support 1.16 'in the circumferential direction of the rolling surfaces 1.17 in two parts. In this example, a leading arch support section is 1.16 " rotatably connected to a sprocket 3.28, which is rotatably connected to those sprockets 3.11 ', which is wrapped by the pair of chains, which carries the gripper bars 3.27 with the second grippers 1.14'. A trailing arch support section 1.16 '"is non-rotatably connected to a 3.36 concentric to the sprocket 3.28, which in turn is rotatably connected to those of the sprockets 3.11', which is looped by the pair of chains, which gripper 3.30 carries, on which trailing edge gripper 3.31 for gripping the trailing For the non-rotatable connection of the arch support sections 1.16 "and 1.16 '" with the sprocket shaft 3.28 or the hollow shaft 3.29, in the present example, spoke-like arranged ribs are provided, with respect to which a respective arch support section 1.16 "and 1.16'. It can be adjusted in the longitudinal direction of the sprocket shaft 3.28 and locked in a manner not shown here.) The adjustment along the sprocket shaft 3.28 takes place analogously to the arch supports 1.16 of the sheet guiding drum 3.6 according to FIG Fig. 4 along T-shaped guides. In order to change the extent of the rolling surfaces 1.17, the phase position of the hollow shaft 3.29 is adjusted relative to the sprocket shaft 3.28 in the present case.

In the FIGS. 2a to 2c For this purpose, suitable embodiments of the arch support sections 1.16 "and 1.16 '" shown. In a first embodiment according to Fig. 2a Each of the two arch support sections 1.16 "and 1.16 '" with a rolling surfaces 1.17 forming rubber elastic tread 3.32 provided, which is fixedly arranged for example by vulcanization, so that the two treads 3.32 act in adjacent tracks of the side edges 2.2'.

In the different areas of the side edges 2.2 'acting embodiments according to the FIGS. 2b and 2c the arch support sections 1.16 "and 1.16 '" are laminated and they have a common tread 3.33 or 3.33' on. This is how in FIG. 2 indicated according to the present embodiment, at the trailing end of the sheet support sections 1.16 '"fixed and at the leading end of the Bogenstützenabschnitte 1.16" by a winding device 3.34 up and unwound, the winding device is preferably biased in terms of shortening the unwound tread 3.33 or 3.33' , The treads 3.33 and 3.33 'preferably comprise a strain-resistant carrier tape.

The treads 3.32 or 3.33 or 3.33 'preferably have such an elasticity that they adapt to the most varied thicknesses of the processed sheet 2.2.

In the Fig. 2 The transferred transfer device for discharging the sheets 2.2 further comprises the downstream suction gripper 1.18 'which lifts the trailing gripper edge 2.2''from the support surface 1.13 of the printing cylinder 1.7 of the printing unit 1.2' The rear edge grippers 3.31 pass through the areas of common normal of the support surface 1.13 and the rolling surfaces 1.17 radially within the path traversed by the rolling surfaces 1.17 take over the trailing gripper edge 2.2 '"from the suction grippers 1.18 in the expiring gusset between the support surface 1.13 and the rolling surfaces 1.17. This is an already indicated difference in the design of the endless conveyor 3.5 to the endless conveyor 3.5 '.

LIST OF REFERENCE NUMBERS

1,1 '

machine section

1.1, 1.1 '

printing unit

1.2; 1.2 '

printing unit

1.3

inking

1.4

dampening

1.5

plate cylinder

1.6

Blanket cylinder

1.7

pressure cylinder

1.8

swinging pre-gripper

1.9

feed drum

1.10

Sheet guide drum

1.11; 1.11 '

arrow

1.12

first gripper

1.13

Support surface of the printing cylinder 1.7

1.14, 1.14 '

second gripper

1.15

axis of rotation

1.16, 1.16 '

arch support

1.16 ", 1.16 '"

Arch support section

1.17

rolling surface

1.18

Suction pads

1.18 '

suction opening

2

investor

2.1

separating device

2.2

bow

2.2 '

pressure-free side edge of the sheet 2.2

2.2 "

leading gripper edge of the bow 2.2

2.2 ''

trailing gripper edge of the bow 2.2

2.3

stack

2.4

Transport and alignment device

2.5

platform

2.6

lifting chain

3

boom

3.1

stacking station

3.2

Druckgutstapel

3.3

platform

3.4

lifting chain

3.5, 3.5 '

endless conveyor

3.6

Sheet guide drum

3.7

transfer drum

3.8

third gripper

3.9

sucker

3.10

Chain

3.11, 3.11 '

Sprocket

3.12

gripper

3.13

pregrippers

3.14

gripper

3.15

Nachgreifer

3.16

circumferential groove

3.17

drum core

3.18

T-slot

3.19

clamping screw

3.20

Recess of the drum core 3.17

3.21

suction device

3.22

Rotation axis of the sheet guiding drum 3.6

3.23

suction air chute

3.24

double arrow

3.25

double arrow

3.26

axis of rotation

3.27

gripper

3.28

sprocket

3.29

hollow shaft

3.30

gripper

3.31

Trailing edge grippers

3:32

tread

3.33, 3.33 '

tread

3:34

winder

Claims (9)

1. Device for transporting a sheet for a sheet-processing machine, in particular a rotary printing press, in a processing direction comprising

   - first grippers (1.12) revolving in a first direction during operation to grip the sheet at a leading edge thereof as viewed in the processing direction,

   - a cylinder (1.7) carrying the first grippers (1.12) and including a support surface (1.13) formed on the circumference thereof for supporting the sheet gripped by the first grippers (1.12),

   - second grippers (1.14') revolving in a second direction counter to the first direction during operation to take over the leading gripper margin (2.2") from the first grippers (1.12), and

   - a single pair of sheet supports (1.16, 1.16') as viewed in the direction of the axis of rotation, the pair of sheet supports (1.16, 1.16') rotating about the axis of rotation in the second direction during operation, wherein the sheet supports (1.16 1.16') have a rolling surface (1.17), which is concentric with the axis of rotation and whose an extension along the axis of rotation is smaller than the width of a respective unprinted lateral margin (2.2') of the sheet and which presses the sheet against the support surface (1.13) only within the respective unprinted lateral margin in the regions of common normals of the support surface and the rolling surfaces,
   characterized by
   suction grippers (1.18) that revolve in the second direction during operation and take over a trailing gripper margin (2.2"') of the sheet (2.2) from the cylinder (1.7), the trailing edge (2.2"') engaged with the support surface (1.13) of the cylinder (1.7) by means of the sheet supports (1.16') and by
   a sheet-guiding drum (3.6) comprising the second grippers (1.14'), the sheet supports (1.16), the suction grippers (1.18).
2. Device according to claim 1,
   characterized by

   - a transfer drum (3.7) provided downstream of the sheet-guiding drum (3.6) and rotating in the first direction during operation and including third grippers (3.8) that take over the leading gripper margin (2.2") from the second grippers (1.14), the transfer drum (3.7) further including suction elements (3.9) that follow the third grippers (3.8) and take over the trailing gripper margin (2.2"') from the suction grippers (1.18), as well as by

   - an endless conveyor (3.5') comprising pre-grippers (3.13) and after-grippers (3.15) that revolve during operation, wherein the pre-grippers (3.13) thereof take over the leading gripper margin (2.2") from the third grippers (3.8) and the after-grippers (3.15) thereof take over the trailing gripper margin (2.2"') from the suction elements (3.9).
3. Device according to claim 1,
   characterized by
   an endless conveyor (3.5) revolving during operation, the endless conveyor (3.5) comprising the second grippers (1.14'), which are provided to take over the leading gripper margin (2.2") from the first grippers (1.12), and trailing-edge grippers (3.31), which take over the trailing gripper margin (2.2"') from the suction grippers (1.18).
4. Device according to claim 3,
   characterized in
   that the trailing-edge grippers (3.31) grip the trailing gripper margin (2.2"') in the exiting region between the support surface (1.13) and the rolling surfaces (1.17).
5. Device according to at least one of claims 1 to 4,
   characterized in
   that the mutual distance between the sheet supports (1.16; 1.16') is adjustable.
6. Device according to at least one of claims 1 to 5,
   characterized in
   that the extension of the rolling surfaces (1.17) in the circumferential direction thereof is adjustable.
7. Device according to at least one of claims 1 to 6,
   characterized in
   that the phase position of the suction grippers (1.18) is adjustable.
8. Device according to claim 2,
   characterized in
   that the phase position of the suction elements (3.9) is adjustable.
9. Sheet-processing machine, in particular a rotary printing press, characterized by
   a device for transporting a sheet according to at least one of claims 1 to 8.

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