EP0570689A1 - Device for tensioning a printing plate on the plate cylinder of a printing machine, particularly a sheet offset printing machine - Google Patents

Abstract

A clamping rail (1) which is assigned to the tail edge of print of a printing plate (10) and is mounted in the gap (4) of a plate cylinder (5) is to be designed in such a way that the trailing edge of the printing plate (10) can be introduced in a simple manner without tilting into the gap (9) of an upper and a lower clamping piece (2, 3). The clamping rail (1) is mounted so as to be pivotable about two pivot axles (A, B) which are formed, for example, by stops (12, 23) fixed to the cylinder and interact in each case with an edge (11) or a contour (24) on the clamping rail (1). The clamping rail (1) is drawn into a completely open position by the force of a prestressed compression spring (16) and can be pivoted via an actuating shaft (19) via lever arms (20) and straps (21). <IMAGE>

Description

The invention relates to a device for clamping printing plates on the plate cylinder of printing presses, in particular sheetfed offset printing presses, according to the preamble of claim 1.

In sheetfed offset printing machines, a printing plate is fastened to the plate cylinder by means of tensioning rails arranged in a cylinder channel and assigned to the printing start and the printing end by first inserting (clamping) the printing start of the printing plate into the corresponding tensioning rail and then also clamping the printing end in the second tensioning rail and then is stretched with force. For the reduction of the time which has to be spent for pulling off an old and a new printing plate, the formation of the printing end tensioning rail is of great importance, since inserting the printing end of a new printing plate, especially with a large format, may be necessary. can be very time consuming.

From DE 3 940 795 C2, DE 3 940 796 C2 and EP 0 431 575 A2 systems for automatic printing plate change are known, in which the removal of an old printing plate and the mounting of a new printing plate from or to the plate cylinder takes place automatically. In addition to storage and receiving areas for the printing plates, these systems also have transport devices for supplying or removing a new or old printing plate while the plate cylinder is being rotated in the corresponding direction. The pressure plates are attached by means of clamping rails the plate cylinder, which, as indicated in the individual documents, have remotely operable devices for the appropriate clamping or clamping.

In the solution according to EP 0 431 575 A2, the new printing plates to be supplied have a bevel at the end of the print and this bevel is inserted into a radial gap between two clamping pieces. For clamping and ultimately also for tensioning, these two clamping pieces are then pivoted in an almost azimuthal direction by an eccentric shaft. The disadvantage here is that the new printing plates to be fed are to be bent at their printing end by a special device. This bending must be done very carefully, as possible. Waviness in the folded area can lead to canting and thus lead to problems when inserting it into the gap of the tensioning rail. Because of the problems to be feared due to ripples, used printing plates with such a system are unlikely to be fed. A folded end of the print is also not easily conveyed by a transport system with a nip.

In the printing plate changing systems according to DE 3 940 795 C2 or DE 3 940 796 C2, non-folded printing plates can be used because of the specially designed printing end clamping rails. For this purpose, the clamping flaps causing the detection have a specially arranged pivot pole, which is known from DE 3 626 936 C1. A clamping flap causing this allows the printing end of the printing plate to be placed on a lower clamping device, but results in a relatively large pivoting angle of the clamping flap. It is disadvantageous here that such a clamping flap pivoted into the open position protrudes correspondingly far out of the circumference of the circle of the plate cylinder and thus impairs a pressure roller which causes the pressure plate to be placed on it.

DE-GM 6 941 597 describes a tensioning rail of a plate cylinder of printing machines assigned to the printing end of a printing plate known, which consists of two relatively movable clamping pieces through which the printing end of the printing plate can be detected. This clamping rail, consisting of the two clamping pieces, is pivotally mounted for clamping about an axis running parallel to the plate cylinder. A disadvantage of the device described is that it is not possible to interact with automatic printing plate changing systems.

From US Pat. No. 1,521,665, US Pat. No. 3,107,609 and EP 0 458 323 A1, it is already known to tension a pressure plate via the force of compression springs, the relaxation being effected by appropriate application of force counter to the spring forces.

The object of the present invention is to develop a device for clamping printing plates on the plate cylinder of printing machines according to the preamble of claim 1 in such a way that simple and safe insertion of the printing end of the printing plate into the corresponding tensioning rail is ensured especially when interacting with an automatic printing plate changing system is.

This object is achieved by the features of claim 1. Further developments result from the subclaims.

To insert the printing end of the printing plate, for tensioning and for correspondingly releasing the printing plate, the tensioning rail according to the invention can be swiveled around one of two axes running parallel to the plate cylinder, depending on the swivel position. The detection area of the tensioning rail, which is designed as a gap, thus executes a curved path with two radii of curvature up to a position in which the pressure plate is completely gripped in order to insert the pressure plate. The pressure plate is then clamped by closing the gap, in that the lower and the upper clamping piece are braced against one another or, in the case of a self-locking clamping device, after the gap has been closed and during a first Pressure plate tensioning phase.

To clamp the pressure plate, the detection area of the clamping rail is now pivoted about the axis that gives the small pivot radius of the gap. This pivoting movement continues until the necessary tensile force is exerted on the pressure end of the pressure plate.

By pivoting the tensioning rail around the two axes described, there is an optimal, slightly curved path of the gap when grasping the pressure plate end (large swivel radius) and, on the other hand, an optimal, force-transmitting lever effect (small swivel radius) for tensioning the pressure plate.

The gap for the detection of the pressure plate end can thus be pivoted over an overall large distance without one or more spring (s) applying the tension force for the pressure plate having to be excessively overpressed (spring force to be stored by an actuating element).

The tensioning rail according to the invention simplifies the mounting of a new pressure plate considerably, since its trailing end does not have to be inserted into the detection area of the tensioning rail designed as a gap, but rather the pressure end of the pressure plate is detected by the described pivoting movement of the tensioning rail. The pressure plate attached to the start of the print on the plate cylinder and drawn up according to its length around its circumference must therefore only be laid flat in the area of the print end, so that a secure detection of the trailing end of the pressure plate is then ensured by the subsequent pivoting of the tensioning rail. The printing end of the printing plate can be applied either by hand or when using the tensioning rail according to the invention in connection with an automatic printing plate changing system by means of a corresponding pressure roller. In the latter case, the pressure roller with a certain force is applied to the plate cylinder and the plate cylinder is then rotated into a corresponding position. Especially when there is a ripple on the end of the printing plate (used printing plates), when using a pressure roller, the swiveling of the tensioning rail ensures that the printing plate is gripped securely.

According to the invention it is particularly provided that the force to be used to tension the pressure plate is applied by at least one spring, in particular a compression spring. Other spring means such as torsion bars or leaf springs can also be used. The compression spring, which is preferably to be selected, is supported at one end in a cylinder-fixed manner and is articulated at its other end with a corresponding pretension via a pull rod on the upper clamping piece. The articulation and the set preload is such that the tensioning rail is pivoted into an open position.

For swiveling the tensioning rail forward from the fully open position, i.e. the clamping rail is moved against the spring force to grasp the pressure plate. For this purpose, an actuating shaft is arranged in the cylinder channel and runs parallel to the cylinder axis, which is articulated, for example, via a lever arm and a bracket in the manner of a toggle lever mechanism on the upper clamping piece of the tensioning rail.

According to the invention it can further be provided that the tensioning rail arranged in the cylinder channel is divided into several identical sections and each section is pivotably mounted in the manner described and is provided with a spring means for tensioning. The application of the clamping force is thus carried out in sections at the end of the printing plate, so that automatic alignment is possible especially in the case of a large printing plate format and, for example, register corrections can also be made by changing the position of a front clamping rail.

The spring means assigned to the individual sections can be used for Register corrections are preloaded accordingly. As a result, an asymmetrical or unilateral warping of the pressure plate in the circumferential direction can be deliberately caused.

The section-by-section subdivision of the tensioning rail results in a modular system, so that plate cylinders must be equipped with a corresponding number of sections in accordance with the printing plate format to be provided. In the 3B format, for example, seven identical sections of the tensioning rail can be provided. An actuating shaft and also a clamping shaft are provided for the sections of the tensioning rail of the same design, the latter being guided through all the sections. The common actuating shaft acts on a corresponding number of lever arms and tabs on the individual sections. The rotation of the common clamping shaft and the actuating shaft can be carried out by motors arranged in the plate cylinder, for example compressed air motors. It can also be provided that one or more actuating devices are fixedly arranged on the frame of the printing press, which act on the shafts in a certain positioning of the plate cylinder via couplings or lever arms.

Furthermore, two exemplary embodiments of the invention are explained with reference to the drawings.

Fig. 1, 2, 3

eine erste Ausführung der Spannschiene in drei verschiedenen Verschwenkstellungen jeweils im Profil,

Fig. 4

eine Draufsicht auf die Spannschiene,

Fig. 5

eine Lagerplatte eines Spannschienen-Abschnittes,

Fig. 6, 7, 8

eine zweite Auführungsform der erfindungsgemäßen Spannschiene.

It shows:

1, 2, 3

a first version of the tensioning rail in three different pivot positions, each in the profile,

Fig. 4

a plan view of the tensioning rail,

Fig. 5

a bearing plate of a tensioning rail section,

6, 7, 8

a second embodiment of the tensioning rail according to the invention.

According to FIGS. 1 to 3, the tensioning rail, denoted overall by 1, consists of an upper and a lower clamping piece 2, 3, which are arranged in the cylinder channel 4 so as to be pivotable by the plate cylinder 5. The upper clamping piece 2 has the profile shown. The lower clamping piece 3 essentially has a U-shaped profile and is connected, for example, to the upper clamping piece 2 with one or more retaining screws 6, so that the lower clamping piece 3 is displaceable in the plane of the drawing relative to the upper clamping piece 2. This mobility is achieved, for example, by the spherical head of the retaining screw 6 and corresponding dimensioning of bores in the clamping pieces 2, 3 (indicated by dashed lines in FIG. 1). The upper outer flank of the lower clamping piece 3 and a straight surface of the upper clamping piece 2 form the clamping surfaces 7, 8 of the gap 9 for the pressure end of the printing plate 10 to be detected. Due to the described displaceability of the lower clamping piece 3 relative to the upper clamping piece 2, one in the Gap 9 inserted pressure plate 10 with the clamping surfaces 7, 8 are detected or clamped.

The upper clamping piece 2 has a prismatic edge 11 in a side facing the bottom of the cylinder channel 4 and approximately diametrically to the position of the corresponding clamping surface 7. This edge 11 is assigned a stop 12 which is arranged in a cylinder-fixed manner on the bottom of cylinder channel 4 and against which the edge 11 of the upper clamping piece 2 bears in the position according to FIG. 1. In a certain angular range, the upper clamping piece 2 with the lower clamping piece 3 can thus be pivoted about the pivot axis A formed by the edge 11 and the cylinder-fixed stop 12. The swivel radius from the gap 9 corresponds approximately to the distance between the clamping surface 7 and the edge 11.

As can be seen from FIG. 4, the length of the tensioning rail 1 is divided into several sections 13 of the same type, each having a section as shown in FIGS. 1 to 3. In each section 13, one end of a pull rod 14 is articulated on the upper clamping piece 2, which is oriented in the direction of the cylinder body and at the other end, for example via a plate 15 with a corresponding thread, engages a prestressed compression spring 16 (FIG. 1). Compression spring 16 extends essentially coaxially to the tie rod 14 and is supported with its other end on a base plate 17 which is attached, for example by means of screws, to the bottom of cylinder channel 4 and has the stop 12. The prestressing force of compression spring 16 can be adjustable via threads on tie rod 14 and plate 15. In addition to the edge 11 on the upper clamping piece 2, a support surface 18 is arranged, by means of which the upper clamping piece 2 is supported by the force of the compression spring 16 in the position shown in FIG. 1 on the base plate 17. This position is exactly the one in which the tensioning rail 1 is fully open and thus defined by the angle of the support surface 18 with respect to the clamping surface 7.

Running parallel to the axis of plate cylinder 5 is an actuating shaft 19 mounted in cylinder channel 4, which, as shown in FIGS. 1 to 4, is articulated to clamping pieces 2 in each section 13 via a lever arm 20 and bracket 21. This articulation takes place here, as can be seen in particular in FIG. 4, via two webs 2.1 attached to the rear of the upper clamping piece 2, which have the edge 11 of the pivot axis A and the support surface 18 according to FIGS. 1-3. By rotating the actuating shaft 19, each upper clamping piece 2 of a section 13 and thus the tensioning rail 1 as a whole can be pivoted against the force of the compression spring 16.

As can be seen in FIG. 4, each section 13 of the tensioning rail 1 is assigned a bearing plate 22 on both sides, which is shown again in a reduced form in FIG. 5. Each bearing plate 22 has on both sides a stop 23 forming the pivot axis B in the form of a cylindrical pin 23.1, about which the upper clamping piece 2 can be pivoted against the force of the compression spring 16. The bearing plates 22 at the format limits have only one pin 23.1 on the side on which a section 13 of the tensioning rail 1 is also provided.

The upper clamping piece 2 has a contour 24 approximately in its central profile area, which corresponds in dimension to that of pins 23.1 (FIGS. 1-3). The contour 24 is attached to both ends of its section 13 in the upper clamping piece 2 such that when the upper clamping piece 2 is pivoted about the pivot axis A of the edge 11 or stop 12 it bears against the pin 23 of the bearing plates 22 after a certain pivoting angle. With continued rotation of the actuating shaft 19, the upper clamping piece 2 is thus pivoted about an axis of the pins 23.1. In this second pivoting phase, the edge 11 lifts off the stop 12; the swivel radius of gap 9 now essentially corresponds to the distance between the clamping surface 7 and the axis of pin 23.1 and is smaller than that of the previous swivel angle. In this second pivoting phase, the tensioning rail 1 can be pivoted via the actuating shaft 19 into a position according to FIG. 2. The end position of this swivel angle results either from a mechanical stop or the extended position of the toggle mechanism 20, 21.

To open or close the gap 9, the lower clamping piece 3 can be displaced with respect to the upper clamping piece 2 via a clamping shaft 25 and can be adjusted with force to the clamping surface 7. Clamping shaft 25 has a cylindrical profile with a flattened side and is inserted in a correspondingly profiled recess 25.1 in a lower part of the upper clamping piece 2. At the clamping shaft 25 is followed by a strip 26 with a trapezoidal profile, which has one or more bores for the passage of the retaining screws 6 (not shown). The upper surface of the strip 26 acts with a roller 27 and an inner surface of the lower clamping piece 3 together like an inclined plane. By appropriate dimensioning of the retaining screw 6 and possibly provided but not shown spring means, the lower clamping piece 3 can also perform a movement in the direction of the clamping surfaces 7, 8. A pull exerted on the lower clamping piece 3 in the detection area 9 (when tensioning the pressure plate 10) thus causes the bar 26 and the roller 27 to generate or increase the clamping force. By turning the clamping shaft 25, the detection area 9 is opened, for which purpose the lower clamping piece 3 can in turn be reset to a starting position by spring means (not shown). All sections 13 of the tensioning rail 1 or the upper clamping pieces 2 are actuated by a clamping shaft 25 which is in particular continuous (FIG. 4). The pivot shaft 25 is able to compensate for any deviations from the pivoting positions of the individual sections 13 by corresponding deformations in the longitudinal direction. The clamping shaft 25 can also be provided between the sections 13 in the region of the bearing plates 22 with compensating couplings.

The bearing plates 22 provided between the individual sections 13 have two bores 28, 29 in addition to the journals 23, bore 28 serving to carry out the clamping shaft 25 and being dimensioned in accordance with the possible pivot position and bore 29 serving, for example, to support the actuating shaft 19 in sections ( 4 and 5). As shown in FIG. 4, two adjacent sections 13 of the tensioning rail 1 are each connected in the area above the bearing plates 22 with a threaded spindle 31, which is formed in the central area, for example as a hexagon, and has a right and a right end at both ends Has left-hand thread. These ends of the threaded spindle 31 are screwed into movable blocks (not shown) in the respective section 13, so that the sections 13 can be braced against one another transversely to the direction of pressure in order to press closer or wider. The not shown movable articulation of the threaded spindles 31 in the sections 13 further ensures that the sections 13 can align relative to one another when the pressure plate is tensioned.

Furthermore, a functional description of the insertion and tensioning of a printing plate follows with the aid of FIGS. 1 to 3.

1, the printing plate 10 is completely pulled up on the plate cylinder 5 by its rotation and the printing end of the printing plate 10 is placed, for example, by a pressure roller 30 (dashed in FIG. 1) in the region of the tensioning rail 1 pivoted into the fully open position. On a side facing the pressure plate 10, the lower clamping piece 3 additionally has a support surface 9.1 in the form of a bevelled continuation of the clamping surface 8. By turning the actuating shaft 19, the tensioning rail 1 is rotated into the position according to FIG. 2 with the gap 9 open, that is to say the pressure plate 10 is inserted into the gap 9, whereupon the gap 10 is closed or the clamping occurs (the clamping shaft 25 is rotated). Then the tensioning of the pressure plate 10 takes place by turning back the actuating shaft 19, so that the tensioning rail 1 is pivoted back by the force of the compression spring 16 (in each section 13) around the pin 23 into a force-determined position, for example according to FIG. 3. The pressure plate 10 is loosened analogously in the opposite direction, the clamping being released, for example, in the position according to FIG. 3 and the tensioning rail 1 then being pivoted into the starting position according to FIG. 1.

6, 7 and 8 show a second embodiment of the tensioning rail 1 according to the invention. The tensioning rail 1 is shown here in profile in 3 pivot positions. FIG. 6 corresponds to the fully open position, FIG. 8 to the fully advanced position and FIG. 7 to the position in which the pivot axes A, B are changed.

The upper clamping piece 2 is supported in this version with an edge 11 formed on its underside in turn on a stop 12, which is on the one hand by a cylindrical surface, for example a base plate 17 and on the other hand by the outer circumference of the actuating shaft 19 or one or more thereon located Bearing 32 (eg needle bearing) is formed. This stop 12 formed by a cylinder-fixed surface and the outer circumference of the actuating shaft 19 or of the bearing or bearings 32 thus forms the pivot axis A. Also in this version, a prestressed spring is preferably attached to the upper clamping piece 2 in this way (with a section-wise subdivision of the tensioning rail 1 each spring) is articulated, through which the upper clamping piece 2 is pulled with a support surface 18 in contact with a cylinder-fixed surface, for example the base plate 17. The upper clamping piece 2 thus assumes the position shown in FIG. 6, which corresponds to the fully open position of the tensioning rail 1. In this and the other drawings, the spring means and their articulation points are not shown;

The upper clamping piece 2 has the profile shown in FIGS. 6, 7, 8, which, following the edge 11, has a contour 24 which corresponds to the outer circumference of the actuating shaft 19 or the bearing 32 thereon.

If the upper clamping piece 2, that is to say the tensioning rail 1, is pivoted about the pivot axis A from the fully open position according to FIG. 6 by rotating the actuating shaft 19, for example via a driving arm, the contour according to FIG. 7 is created 24 to the outer periphery of the actuating shaft 19 or the bearing (s) 32. The pivoting of the tensioning rail 1 now takes place in such a way that the upper clamping piece 2 is pivoted about the actuating shaft 19, which now forms the pivot axis B.

The edge 11 of the upper clamping piece 2 thus lifts off the stop 12 of the pivot axis A. The tensioning rail 1 is now, from the position shown in FIG. 7, pivoted about the pivot axis B of the actuating shaft 19 into the fully advanced position shown in FIG. 8, by a mechanical not shown or a path limitation the actuating shaft 19 can be defined.

The lower clamping piece 3, as shown in FIGS. 6, 7, 8, has an L-shaped profile and, for example, is mounted opposite the upper clamping piece 2 in a manner similar to that described above. A clamping shaft 25 here also has a flattened side and is supported in the manner of an inclined plane on a surface of the upper clamping piece 2. The clamping shaft 25 opens or closes the gap 9 formed by the clamping surfaces 7, 8 between the upper and lower clamping pieces 2, 3 for gripping / releasing the pressure plate 10.

6, 7, 8 can also be pivoted about a total of two pivot axes A, B, the gap 9 for gripping the pressure plate 10 from the fully open position (FIG. 6) with a large pivot radius about the pivot axis A and then after the pressure plate 10 has been gripped with a smaller pivot radius about the pivot axis B (FIGS. 7 and 8). The tensioning of the pressure gap 10 takes place after relieving the actuating shaft 19 via the force of the articulated spring (s), so that the tensioning rail 1 assumes a position between those of FIGS. 7 and 8 which results in force.

In the last-described exemplary embodiment, the actuating shaft 19 can cause the tensioning rail 1 to swivel forward via a driving arm, which acts on a rear part of the upper clamping piece 2, for example in the region of the support surface 18. However, the actuating shaft 19 can in turn be articulated on the upper clamping piece 2 via at least one lever arm and at least one bracket (not shown).

In both exemplary embodiments, the swivel axis A is designed in the manner of a cutting joint and the swivel axis B is designed as a swivel joint, which is to be regarded as a preferred embodiment of the general inventive concept.

Reference symbol list

1

Tensioning rail

2nd

upper clamp

2.1

web

3rd

lower clamp

4th

Cylinder channel

5

Plate cylinder

6

Retaining screw

7

Clamping surface (upper clamping piece 2)

8th

Clamping surface (lower clamping piece 3)

9

gap

9.1

Support surface

10th

printing plate

11

Edge

12

attack

13

Section (tensioning rail 1, upper and lower clamping piece 2, 3)

14

pull bar

15

Plate

16

Compression spring

17th

Base plate

18th

Support surface

19th

Actuating shaft

20th

Lever arm

21

Tab

22

Bearing plate

23

attack

23.1

Cones

24th

contour

25th

Clamping shaft

25.1

Recess

26

strip

27

role

28

Bore (clamp shaft 25)

29

Bore (actuation shaft 19)

30th

Pressure roller

31

Threaded spindle

32

warehouse

A

Swivel axis

B

Swivel axis

Claims (19)

Device for clamping printing plates on the plate cylinder of printing presses, in particular sheetfed offset printing presses, in which a printing plate attached to the start of the print can be fastened in the region of the print end with a tensioning rail arranged in the cylinder channel, for which purpose the tensioning rail for receiving the printing plate has one by two clamping surfaces of an upper and one lower clamping piece formed gap which can be closed by a device assigned to the clamping pieces and the clamping rail for clamping the pressure plate is pivotable parallel to the axis of the plate cylinder,
characterized by
that the tensioning rail (1) is assigned two swivel axes (A, B), so that the tensioning rail (1) is first defined by the distance to the gap (9) via a hinged actuating device from a fully open position about the swivel axis (A) large swivel radius and then about the swivel axis (B) with a smaller swivel radius defined by the distance to the gap (9). Device according to claim 1,
characterized by
that the pivot axes (A, B) are designed as two cylinder-fixed stops (12, 23) which cooperate in this way with regions (11, 24) formed on the tensioning rail (1), so that the tensioning rail (1) in each case around one of these Stops (12, 23) is pivotable. Device according to claim 2,
characterized by
that the pivot axis (A) forming the stop (12) is formed as a step in the bottom of the cylinder channel (4), on which the tensioning rail (1) is supported via an edge (11) attached to its lower part in the manner of a cutting joint . Device according to claim 2 or 3,
characterized by
that the pivot axis (B) forming the stop (23) is designed as a cylinder-fixed pin (23.1) assigned to the ends of the tensioning rail (1), each with a contour (24) shaped on the tensioning rail (1) in the manner of a Swivel joint cooperates. Device according to claims 1 to 4,
characterized by
that the shaped areas (11, 24) are attached to the upper clamping piece (2) of the tensioning rail (1). Device according to one of the preceding claims,
characterized by
that the tensioning rail (1) on the lower side of the upper clamping piece (2) has a support surface (18) on which the tensioning rail (1) rests on the bottom of the cylinder channel (4) in the fully open position. Device according to one of the preceding claims,
characterized by
that the actuating device is designed as a prestressed spring which pulls the tensioning rail (1) into a fully open position and the tensioning rail (1) can be pivoted against the force of this spring via the actuating device. Device according to claim 7,
characterized by
that the spring is designed as a cylinder-supported pressure spring (16) which is articulated at the other end via a pull rod (14) on the tensioning rail (1). Device according to one of the preceding claims,
characterized by
that the actuating device for pivoting the tensioning rail (1) has an actuating shaft (19) running parallel to the axis of the plate cylinder (5). Device at least according to claims 1 and 9,
characterized by
that the actuating shaft (19) forms the swivel axis (B) for the tensioning rail (1), in that the actuating shaft (19) is arranged below the tensioning rail (1) and this forms a contour (24) that forms part of the outer circumference of the actuating shaft (19) ) on which the tensioning rail (1) can be supported on the actuating shaft (19) in the manner of a swivel joint. Device according to claim 10,
characterized by
that the actuating shaft (19) has bearings (32), in particular in the form of needle bearings, over the outer circumference of which the tensioning rail (1) is supported with the contour (24). Device according to one of claims 9 to 11,
characterized by
that the actuating shaft (19) is articulated to the tensioning rail (1) via at least one lever arm (20) and a tab (21). Device according to one of claims 9 to 11 in connection with claim 7 or 8,
characterized by
that the actuating shaft (19) acts on the tensioning rail (1) via at least one driver arm. Device according to one of the preceding claims,
characterized by
that the upper and lower clamping piece (2, 3) of the tensioning rail (1) is divided over the format width into a number of identical sections (13) and the sections (13) can be pivoted together by the actuating device. Apparatus according to claim 14 in conjunction with claim 7 or 8,
characterized by
that the sections (13) of the tensioning rail (1) each have a prestressed spring arranged. Device according to claim 4 and claims 14 or 15,
characterized by
that two sections (13) of the tensioning rail (1) are assigned an intermediate bearing plate (22) with the stops (23) designed as pins (23.1) for the pivot axis (B). Device according to one of the preceding claims,
characterized by
that the stops (12) for the pivot axis (A) are attached to a base plate (17) attached to the bottom of the cylinder channel (4). Device according to one of the preceding claims,
characterized by
that a support surface (9.1) in the form of a bevel for the pressure plate (10) to be inserted is attached to the lower clamping piece (3) in the region of the gap (9). Device according to claim 14,
characterized by
that two adjacent sections (13) of the tensioning rail (1) can be clamped against each other in the axial direction by the plate cylinder (5) by means of a threaded spindle (31), each having right-hand and left-hand threads.

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