EP3962743B1 - Blanket cylinder and method for handling a rubber blanket - Google Patents

Description

The invention relates to a blanket cylinder of a printing unit of a printing press for carrying at least one rubber blanket and a method for handling, in particular for automated or manual tensioning, retensioning or loosening, a rubber blanket on a blanket cylinder in a printing unit for a printing press, in particular an offset printing press.

In order to change a rubber blanket, for example on a sheet-fed printing press, the rubber cylinder is currently moved to the appropriate position. The old rubber blanket is slackened manually or with an electrically operated screwdriver. The tensioning spindle at the end of the cloth is first slackened and then the blanket is released from the tensioning shaft. The operator then guides the rubber blanket out while the rubber cylinder is slowly turning. The tensioning spindle at the beginning of the cloth is then released again manually or with a cordless screwdriver and the blanket is completely removed. The new rubber blanket is mounted in reverse order. Then both clamping spindles are tightened with a torque wrench. After specified times or after a certain number of sheets, the rubber blankets that have been changed are tightened. The entire procedure is very time-consuming and also very strenuous when operated manually.

From the DE 41 27 714 A1 a device for fastening and tensioning a printing blanket on a cylinder of a printing press is known, which has a bore for actuating a tensioning screw. The disadvantage of this solution is that always manual operations are necessary. There can be no automation.

From the DE 92 18 269 U1 a device for tensioning a rubber blanket is known, wherein tensioning screws of a tensioning rail are actuated by simultaneously activatable motors of a carrier. The carrier has handles for handling and is placed on the clamping screws from outside the cylinder. Disadvantages of this solution are the great expense and the need to provide a suitable carrier for the respective machine width.

From the DE 10 2005 008 241 A1 discloses a device for tensioning a packing on a cylinder of a rotary printing press with tensioning shafts divided into shaft sections, with a single adjustment drive, which can be rotated manually or by motor, being provided for each tensioning shaft to turn the tensioning shafts, which is arranged in the forme cylinder and rotates on a roller section acts. A disadvantage of this solution is the extremely large amount of work involved with many components and the necessary rubber blankets. Furthermore, the actuation can either be carried out by hand or exclusively by motor, with manual intervention not being possible. In this case, the necessary fail-safety cannot be achieved.

From the DE 10 2007 057 455 B4 a printing machine with a printing plate manipulation device is known, with actuators changing the geometry of a cylinder packing in the axial and/or circumferential direction after a target/actual value comparison of an image inspection device. The actuators should act directly on the outer edge of the elevator. The elevator can be a blanket of a blanket cylinder. Disadvantages of this solution are the great expense and the susceptibility to failure of the large number of actuators. If an actuator fails, adjustments can no longer be made, resulting in an interruption in printing.

From the DE 10 2012 202 076 B3 a rubber blanket cylinder of a rotary printing press is known, with a tensioning spindle or tensioning shaft being provided for receiving the leading edge of the rubber blanket and a tensioning spindle or tensioning shaft being provided for receiving the rear edge of the rubber blanket.

The U.S. 2014/230673 A1 discloses a blanket cylinder of a printing unit. The blanket cylinder has a cylinder channel with a dynamic beam and a static beam. In addition, it is disclosed that in another embodiment, the one static bar can be replaced with another dynamic bar. The dynamic beam can be rotated about an axis for tensioning a blanket towards the static beam. A force can be applied to the dynamic beam by means of springs. The springs can be tensioned/relaxed by means of an actuating screw, which is located on the front side of a cylinder. The actuating screw can be actuated by means of a controllable motor. The springs and the actuating screw can generally be understood as drive means.

The U.S. 5,069,127 A discloses a rubber cylinder with two rotatable and continuous tensioning shafts for clamping and tensioning the leading and trailing edges of a rubber blanket. The expansion shafts are rotated via a shaft by inserting a tool into the hole.

The invention is based on the object of creating an alternative blanket cylinder or an alternative method for handling, in particular for automated or manual tensioning, retensioning or releasing a rubber blanket on a blanket cylinder in a printing unit. In particular, the blanket change should at least partially automated or fully automated and/or manual intervention may be made possible.

According to the invention, the object is achieved by the features of the independent claims. Advantageous configurations result from the dependent claims, the description and the drawings.

The invention has the advantage that an alternative blanket cylinder or an alternative method for handling, in particular for automated or manual tensioning, retensioning or loosening, a blanket on a blanket cylinder in a printing unit is provided. A roll-fed or sheet-fed offset printing machine with at least one or more such printing units is preferably also provided. In particular, changing the rubber blanket is at least partially automated or fully automated and/or manual intervention is made possible.

According to an advantageous embodiment, changing a rubber blanket or handling, in particular tensioning, retensioning or loosening, of a rubber blanket can be simplified and/or at least partially automated or fully automated. The functional reliability can be increased by the possibility of a manual or manual intervention.

Advantageously, the continuous tensioning shafts or tensioning spindles, which have been tried and tested in many respects, can be used to tension the rubber blankets. Instead of the manual drive means, an electric motor, preferably with an additional gear, is advantageously installed in the blanket cylinder for each tensioning shaft or tensioning spindle. The voltage is preferably supplied via a rotary feedthrough of the blanket cylinder. Accordingly, the motor driver can be located outside the blanket cylinder.

Changing the rubber blanket without tools is particularly advantageous thanks to the automatic rubber blanket tensioner. The operator can, for example, preselect the blanket change, with the machine positioning the blanket cylinder and/or already slackening the blanket by motor. The operator now only has to pull out the rubber blanket while the machine is rotating slowly. The loosening can also be motorized on the end of the cloth.

If the required rubber blanket tension is reached during tensioning or retensioning, the power consumption increases due to the increasing resistance. When a maximum set current is reached, the motor driver switches off preferentially. Later tightening can then be done from the control station, for example. Advantageously, existing protections on the printing tower do not have to be opened for this purpose, and the blanket cylinder in question also does not have to be brought into a specific position.

In order to avoid damage or to switch off when an end position is reached, switches or indirectly working initiators can interrupt the power supply to the motor. For example, a diode connected in parallel can allow the motor to be driven in the opposite direction. As soon as the end position has been left using the assigned diode, the motor can be operated in both directions again.

For example, by limiting the current, the desired torque can advantageously be achieved during clamping, with clamping with a torque wrench also no longer being necessary. Retensioning after some time can also be done automatically. For example, the printer can select the blanket tensioning function in the control station or at the printing unit. The machine can now automatically tension or re-tension the rubber blankets in one, several or all units, with manual operation no longer being necessary. This saves a considerable amount of time and increases user-friendliness.

Advantageously, the rubber blanket on a rubber cylinder in the printing unit, for example an offset printing press, in particular a sheet-fed offset rotary printing press, can thus be changed without tools. As a rule, manual clamping work is no longer necessary, which, in addition to saving time through automatic re-clamping, also means greater comfort for the operator. The tried-and-tested tensioning shafts or tensioning spindles can preferably remain the same, which makes it possible to use the existing rubber blankets. Furthermore, the possible preselections, for example in the machine control, save a considerable amount of time.

Fig. 1:

Druckwerk einer bogenverarbeitenden Maschine mit einem Farb- und Feuchtwerk;

Fig. 2:

Längsschnitt des Gummizylinders mit integrierten Elektromotoren zur Gummituchspannung;

Fig. 3:

Querschnitt des Gummizylinders mit im Zylinderkanal angeordneten Spannwellen zur Aufnahme eines Gummituches;

Fig. 4:

Ausschnitt eines Längsschnittes durch eine von einem Elektromotor betätigbare Spannschraube;

Fig. 5:

Ausschnitt eines Längsschnittes durch eine von einem Elektromotor entkoppelte manuell betätigbare Spannschraube;

Fig. 6:

Spannvorrichtung mit einem die Gewindespindelumdrehungen ermittelnden Sensor;

Fig. 7:

Gummizylinder mit Sicherheitsschaltern;

Fig. 8:

Schaltplan zur Motoransteuerung.

The invention is to be explained below by way of example. The associated drawings show the following schematically:

Figure 1:

Printing unit of a sheet-processing machine with an inking and dampening unit;

Figure 2:

Longitudinal section of the blanket cylinder with integrated electric motors for blanket tensioning;

Figure 3:

Cross-section of the blanket cylinder with tensioning shafts arranged in the cylinder channel to accommodate a blanket;

Figure 4:

Detail of a longitudinal section through a clamping screw that can be actuated by an electric motor;

Figure 5:

Section of a longitudinal section through a manually operated clamping screw decoupled from an electric motor;

Figure 6:

Clamping device with a sensor that detects the revolutions of the threaded spindle;

Figure 7:

rubber cylinders with safety switches;

Figure 8:

Circuit diagram for motor control.

The 1 shows, for example, a section of an offset printing press, for example a sheet-fed offset printing press, in particular a sheet-fed rotary offset printing press, preferably in aggregate and in-line construction. The machine contains one or more units, which can be designed, for example, as attachment, printing, coating, drying and/or finishing units. At least one of the works of the machine is equipped as a printing unit 1 with an inking unit or inking and dampening unit 2 . Furthermore, the machine can contain a feeder for sheet feeding and a delivery for outputting the processed sheets. A turning device can also be arranged between two works of the machine, with which the sheets can be turned in perfecting printing.

In particular, the machine contains endlessly revolving driven sheet conveyor systems that guide the sheets to be processed through the machine or transfer them between the plants. Between the sheet conveyor systems, the sheets are, for example, in Hand over the gripper closure at the leading edge. For example, the circulatingly driven sheet conveying systems can be sheet guiding cylinders driven in rotation, such as printing cylinders, transfer cylinders and/or transfer cylinders. The sheet conveyor systems or rotary bodies in the printing unit(s) 1 can be driven, for example, by a drive train of wheels, in particular a continuous drive gear train. The sheet-guiding cylinders or the corresponding rotary bodies of the printing units 1 each have meshing gears that form the drive gear train. The drive wheel train is driven by at least one main drive motor that can be controlled by a machine control. In a further development, other drives can also be connected to the drive wheel train as a motor or as a generator.

One or more units, in particular printing units 1, of the machine can, for example, each contain a printing cylinder 3, with such a printing cylinder 3 in particular having an at least approximately full-surface lateral surface for carrying the sheet. The sheets can be transferred between the printing cylinders 3, for example by transfer drums 4 or transfer drums. The pressure cylinder 3 and the transfer drums 4 can preferably be double-sized. A double-sized cylinder can, in particular, accommodate two sheets of maximum format on the circumference. The double-sized impression cylinders 3 and transfer drums 4 preferably each have gripper systems 5 for clamping the leading edges of the sheet. These gripper systems 5, which are arranged diametrically opposite one another in gripper channels, clamp and thus hold the sheet to be processed on the printing cylinder 3 or on the transfer drum 4.

The machine, which is only shown in part, contains here, for example, at least one printing unit 1, which applies or applies ink to the sheets during a printing process by means of an inking unit or inking and dampening unit 2. An inking unit or inking and dampening unit 2 of a printing unit 1 contains, in particular, surface contact rotating bodies that can be brought together or that are in contact, such as rollers and cylinders. In particular, a printing unit 1 of a sheet-processing machine contains a forme cylinder or plate cylinder 7 and a transfer cylinder or blanket cylinder 6. A blanket cylinder 6 of a printing unit 1 interacts with a respective printing cylinder 3 and forms a printing gap with it. For example, the blanket cylinder 6 and the plate cylinder 7 can be designed as single-sized, with single-sized cylinders being able to accommodate approximately one sheet of maximum format on the circumference. Alternatively, the sheet guiding cylinders or the rotary bodies of the printing units 1 can also have other sizes or a different arrangement.

In the printing process, an inking unit or inking and dampening unit 2 of a printing unit 1 applies the appropriate printing ink to a printing plate clamped on the respective plate cylinder 7 . A plate cylinder 7 is inked by at least one, but preferably more, rollers of the associated inking unit or inking and dampening unit 2 during its rotation. The inking or inking and dampening unit 2 has here, for example, an ink fountain, not shown, with an ink chamber formed by the ink fountain with a ductor roller. The printing ink in the ink chamber is preferably transferred from the duct roller to subsequent ink transfer rollers or traversing rollers via ink gaps that can be adjusted in zones. The ink transfer rollers or traversing rollers distribute the printing ink in the inking unit before it is transferred to the printing plate clamped on the plate cylinder 7 by inking rollers employed on the plate cylinder 7 . When the plate cylinder 7 rolls on the blanket cylinder 6, the printing ink is transferred to the blanket cylinder 6, which is covered with a blanket, in accordance with the motif. In particular, the blanket cylinder 6 takes up a single blanket or printing blanket at a leading end and at a trailing end. With respect to a direction of rotation of the blanket cylinder 6 in the printing process leading end can also be used as a leading edge and the trailing end with respect to a direction of rotation of the blanket cylinder 6 in the printing process can also be referred to as the trailing edge.

In the nip to the impression cylinder 3, the printing ink is transferred from the blanket cylinder 6 to the sheet to be printed, which is conveyed by the impression cylinder 3 by means of a gripper system 5, in accordance with the motif. Dampening unit rollers can be operatively connected to a first inking roller, for example via a preferably switchable bridge roller. If you work in dry offset, for example, no dampening system is required. One, several or all of the rollers of the inking unit or inking and dampening unit 2 can be coupled to the drive train of wheels during the printing process, for example, and can therefore be driven by the main drive motor. Outside of the printing process, one, several or all of the rollers of the inking or inking and dampening unit 2 can be separated from the drive wheel train or main drive motor and/or connected to an additional drive of the printing unit 1.

The plate cylinder 7 and the blanket cylinder 6 of a respective printing unit 1 preferably have a cylinder pin on each side, via which they are rotatably mounted in the frame of the respective printing unit 1 and, if necessary, adjustable. Both the plate cylinder 7 and the blanket cylinder 6 preferably have bearer rings (not shown) arranged on both sides. The plate cylinder bearer rings are in contact with the blanket cylinder bearer rings during the printing process and roll off one another under pressure. The plate cylinder 7 can either be driven by the drive gear train, in particular via a gear wheel from the drive gear train, or by an individual drive, for example a plate cylinder direct drive. A rotor of a plate cylinder direct drive can be attached, for example, in alignment with the shaft of the plate cylinder 7 or can drive the plate cylinder 7 independently of the other cylinders or rollers of the printing unit 1 . The drive can take place in the printing process and/or outside of the printing process, for example in a washing process.

The 2 shows a longitudinal section of a blanket cylinder 6, for example a machine described above, with integrated drive means or actuators for rubber blanket tension. The rubber cylinder 6 has a continuous, i.e. in particular one-piece or format-wide, tensioning shaft 9 for clamping and tensioning a leading edge of the rubber blanket and a continuous, i.e. in particular one-piece or format-width, tensioning shaft 9 for clamping and tensioning a trailing edge of the rubber blanket, with the tensioning shafts 9 for tensioning the rubber blanket are accommodated so as to be rotatable about their respective axis of rotation. The clamping shafts 9 are preferably designed with a diameter that remains constant over the format width. The tensioning shafts 9 in particular each have an axis of rotation which is oriented parallel and at a distance from the axis of rotation of the blanket cylinder 6 . In particular, the clamping shafts 9 can be arranged parallel to one another or in a cylinder channel 8 of the blanket cylinder 6 . The drive means for driving a respective tensioning shaft 9 in rotation here comprise at least one controllable actuator arranged in the blanket cylinder 6 .

An electric motor 11 for the tensioning shaft 9 for clamping and tensioning the leading edge of the blanket or an electric motor 11 for the tensioning shaft 9 for clamping and tensioning the trailing edge of the blanket in the blanket cylinder 6 are provided as actuators. The electric motors 11 are preferably arranged in the rubber-covered cylinder body in such a way that their rotors are arranged parallel to the axis of rotation of the rubber-covered cylinder 6, while their stators are fixedly arranged in the cylinder body, in particular screwed. Preferably, a gear, for example an angular planetary gear 12, can be provided for each electric motor 11, which is connected on the input side to the respective rotor of the electric motor 11, in particular firmly. On the output side, for example, a gear element can be arranged radially to the blanket cylinder 6 .

Particularly preferably, both electric motors 11 are each provided with an associated gear, in particular angular planetary gear 12, approximately in the middle of the blanket cylinder 6. In particular, a separately controllable electric motor 11 is assigned to each tensioning shaft 9 . In particular, the motor driver of one or both electric motors 11 can be located in the electric vessel, in which case the current can preferably be conducted to the rubber-covered cylinder 6 via a rotary feedthrough. The automatic tensioning device is particularly preferably installed exactly twice per rubber cylinder 6, so that the rubber blanket tension for the start of printing and the end of printing can be adjusted together or separately. Several or all rubber cylinders 6 of the machine preferably have actuators designed in this way, in particular electric motors 11 . The electric motors 11 can preferably be actuated, in particular electronically, preferably via a motor driver from the control device or the machine control.

The 3 shows a cross section of the rubber cylinder 6 with arranged in the cylinder channel 8 tensioning shafts 9 for receiving a rubber blanket. In particular, the tensioning shaft 9 for clamping and tensioning the leading edge of the rubber blanket and the tensioning shaft 9 for clamping and tensioning the trailing edge of the rubber blanket each have a suspension 10 for the rubber blanket. A suspension 10 of a tensioning shaft 9 can be a recess in the tensioning shaft 9 which is arranged radially to the tensioning shaft 9 and which preferably extends over the entire width of a rubber blanket to be used. For example, a suspension 10 can also extend over the entire width of a tensioning shaft 9 or be a longitudinal groove. In particular, a respective format-wide suspension 10 thus extends over the maximum width of a printing material to be processed by the machine, with the width extending from one machine side wall to the other machine side wall. By rotating a tensioning shaft 9 about its axis of rotation, the attachment 10 is displaced in the circumferential direction of the tensioning shaft 9 and a suspended rubber blanket can be pulled or tightened in a first direction of rotation and in a the rubber blanket can be loosened or removed in the opposite direction of rotation. A cylinder segment between the clamping shafts 9 is particularly preferably arranged, for example, at the level of or slightly below the periphery of the blanket cylinder 6 . The cylinder segment can be formed onto one or preferably both clamping shafts 9 .

In particular, each clamping shaft 9 is assigned a threaded spindle or clamping screw 13 oriented approximately or exactly radially with respect to the blanket cylinder 6 , which has an axis of rotation correspondingly oriented radially with respect to the blanket cylinder 6 . A respective clamping screw 13 has an external thread with a preferably flat pitch and penetrates through a threaded plate 14, which has an internal thread corresponding to the external thread. A clamping screw 13 can, for example, be rotated by an electric motor 11 via the gear, specifically angular planetary gear 12 . The rotary movement can take place in both directions.

The threaded plate 14 is held in such a way that when the clamping screw 13 is rotated, the threaded plate 14 can be displaced or is displaced radially with respect to the blanket cylinder 6 . A respective threaded plate 14, as in 2 shown, be connected on both sides via sliding blocks 15A, 15B and couplings 16A, 16B to a tensioning shaft 9, with a radial displacement of the threaded plate 14 causing a rotational movement of the tensioning shaft 9 about its own axis of rotation. The couplers 16A, 16B can be arranged parallel to one another or radially to the respective tensioning shaft 9, for example. The couplers 16A, 16B and the sliding blocks 15A, 15B guided by the threaded plate 14 connected to them can be mirror-symmetrical. The two sliding blocks 15A, 15B prevent the threaded plate 14 from rotating. The tensioning device for the further tensioning shaft 9 is preferably designed analogously or as a mirror image and is not shown in any more detail.

A releasable coupling connection is preferably provided between an actuator, in particular an electric motor 11, and a tensioning shaft 9. For example, a coupling connection that can be released manually or by means of a tool can be provided between the gear, in particular angular planetary gear 12, and the clamping screw 13. A gear element, in particular a push rod 17 , is particularly preferably accommodated in the interior by a clamping screw 13 . The push rod 17 can be displaced within the clamping screw 13, with a compression spring 18 holding the push rod 17 in an outer position. In this outer position, close to the cylinder jacket, the push rod 17 closes or covers an access opening for tools. The access opening can be the inner wall of the clamping screw 13, for example. The gripping opening can have a gripping point or a carrier profile, in particular an Allen key shape, of the clamping screw 13 . The engagement opening in the cylinder segment arranged between the tensioning shafts 9 is preferably arranged slightly below the periphery of the circumference of the blanket cylinder. Both clamping screws 13, which can each be connected to an electric motor 11, are preferably located at the same height or in the same surface line of the rubber cylinder circumference.

The compression spring 18 holding the push rod 17 in an outer position preferably at the same time creates a connection between a lock 19 connected to the flange of the gear, in particular an angle planetary gear 12 , and the clamping screw 13 . The displaceable lock 19 can be designed, for example, with a spline profile. The lock 19 is preferably pressed against a surface of the clamping screw 13 so that this produces a positive and/or non-positive connection, in particular a torsion-resistant connection, between the lock 19 and the clamping screw 13 . By shifting the push rod 17 against the compression spring 18, the lock 19 is also shifted in addition to the compression spring 18 in such a way that the connection between the clamping screw 13 and the lock 19 is loosened or eliminated. This is from within the Clamping screw 13 shifting push rod 17 a coupling connection, in particular between lock 19 and clamping screw 13, made or released.

The 4 shows a section of a longitudinal section through a clamping screw 13 which can be actuated by an electric motor 11 and which displaces the threaded plate 14 with a corresponding rotation. The push rod 17 is held in its outer position by the compression spring 18, and at the same time a coupling connection of the lock 19, which is connected to the gear, in particular an angular planetary gear 12, to the clamping screw 13 is produced. In the outer position, an engagement opening or a driving profile, for example a hexagon socket 20, of the clamping screw 13 is closed by the push rod 17.

The figure 5 shows a section of a longitudinal section through a manually operable clamping screw 13 that is decoupled from an electric motor 11 and that moves the threaded plate 14 with a corresponding manual rotation. By moving the push rod 17 within the clamping screw 13 against the spring force of the compression spring 18, for example by a tool, the access opening, in particular the hexagon socket 20, is automatically released for the tool. The coupling connection between the electric motor 11 and the clamping screw 13 is preferably released at the same time. In particular, the coupling connection of the lock 19 to the clamping screw 13, which is connected to the gear, in particular angular planetary gear 12, is released or canceled by the push rod 17 in the inner position. The push rod 17 preferably has a collar on the side toward the center of the cylinder and is thus protected against loss. An additional fuse is not necessary.

The 6 shows, for example, a clamping device with a sensor that detects the revolutions of the threaded spindle, in particular an inductive sensor 21. In this case, an inductive sensor 21 is preferably installed in the clamping device for the clean cloth spindle thread spindle revolutions. For example, one pulse is output per revolution. This means that when the rubber blanket is inserted, a certain number of turns of the clamping screw 13 can be automatically pretensioned on the print start side.

The rubber blanket can then be pulled onto the rubber cylinder 6 and hung and tensioned in the printing end side. This is followed by the finished clamping with the desired torque, preferably one after the other. For example, the speed or the tensioning time can be adjusted by adjusting the voltage supply of the electric motor(s) 11 . The output torque can preferably be determined by adapting the current.

The 7 shows a rubber cylinder 6 with safety switches, in particular limit switches S1.1, S1.2, S2.1, S2.2. In order to avoid mechanical damage to the components when the end positions are reached or jamming, the power supply is interrupted. Limit switches S1.1, S1.2, S2.1, S2.2 are installed for this purpose, which interrupt the circuit when an upper or lower end position is reached. Diodes are installed in parallel with the limit switches S1.1, S1.2, S2.1, S2.2, which enable the turning of a respective electric motor 11 from the relevant end position. Once the expansion shafts 9 have left the area of the end positions again, the end position switches S1.1, S1.2, S2.1, S2.2 close again and rotation in both directions is possible.

The 8 shows a circuit diagram for the two electric motors 11 arranged in the blanket cylinder 6, which are supplied with electricity via a rotary inlet. Depending on the translation and the efficiency between an electric motor 11 and a clamping shaft 9, the current results in the resulting clamping torque or the resulting clamping force. In order to always achieve approximately the same clamping force, the voltage is supplied to the electric motors 11 when a rated current is reached switched off. A current-voltage converter emits the required signal for this. Furthermore, the current-voltage converter can be used to detect whether the electric motors 11 are still rotating or whether the limit switches S1.1, S1.2, S2.1, S2.2 have already been reached.

About the mode of operation: A clamping shaft 9 is tensioned or released via a rotating threaded spindle or clamping screw 13 and sliding parts such as sliding blocks 15A, 15B and couplers 16A, 16B. The clamping screws 13 or clamping shafts 9 are driven in particular via a respective controllable electric motor 11. The control can be remotely controlled by the connected control device or the machine control. The electric motors 11 that are preferably used transmit a torque via a respective gear, specifically an angular planetary gear 12, to the respective clamping screw 13. An additional brake on the clamping screw 13 is not necessary, since the small thread pitch of the clamping screw 13 means that the electric motor 11 or the angular planetary gear 12 sufficient self-locking is achieved to prevent unintentional relaxation during operation.

From the flange or guide flange of the gear, in particular of the angular planetary gear 12, the torque is transmitted, for example, by means of a splined hub profile, as a result of which an axial displacement of the lock 19 is made possible. A bore for counting the revolutions can preferably be provided, for example. In particular, the inductive sensor 21 can count.

When the lock 19 is closed (which has not been displaced by the push rod 17 against the compression spring 18), the torque is transmitted from the transmission output to the lock 19 via the screwed-on flange, more preferably via the splined profile. From there, the torque is transmitted to the clamping screw 13, for example via a slot and the matching rectangular profile. Other profiles can also be used.

When the lock 19 is depressed (which is pushed against the compression spring 18 by the push rod 17, for example), the rectangular profile is pushed out of the slot and no longer forms a positive connection. The transmission of torque from the clamping screw 13 to the clamping shaft 9 can thus take place via the carrier profile, for example the hexagon socket 20, of the clamping screw 13. If the lock 19 is released, the compression spring 18 pushes the lock 19 back in the direction of the clamping screw 13. Turning the electric motor 11 results in a rectangular profile and slot, so that the lock 19 locks and can transmit torque again.

The inductive sensor 21 preferably detects the number of revolutions of the clamping screw 13 for the front edge of the rubber blanket. If an old rubber blanket was unclamped, the expansion shaft 9 is in the "blanket relaxed" position. A new blanket is first inserted into the tension shaft 9 of the print start side. The tensioning screw 13 is then pretensioned by a few turns. Among other things, to prevent the rubber blanket from falling out. If the rubber blanket is changed by hand, the revolutions for pretensioning are counted. In the case of motorized rubber blanket tensioning, the number of revolutions on the side of the beginning of the blanket is recorded by the sensor, in particular inductive sensor 21, at high speeds and the electric motor 11 is switched off when a previously programmed number of revolutions is reached. This function is only of interest for the front edge, since the rear edge is always clamped until the nominal torque is reached.

If, for example, the maximum tightening torque of the clamping screw 13 is reached during clamping, the power consumption increases and the motor driver switches off the voltage supply of the electric motor 11 in particular. If, for example, the upper or lower end position of the threaded plate 14 on the clamping screw 13 is reached without the current consumption increasing, a directly or indirectly operating safety switch opens, in particular limit switches S1.1, S1.2, S2.1, S2.2, and the electric motor 11 stops in order not to destroy any components. Particularly preferably, diodes provided in the circuit allow the electric motor 11 to rotate in order to move out of the end position again.

In particular, a respective clamping screw 13 can be rotated manually by means of an emergency release in order to enable the rubber blanket to be changed in the event of a failure of the clamping device, for example an actuator such as an electric motor 11 . For the manual tensioning, re-tensioning or loosening of a rubber blanket on a rubber cylinder 6 in a printing unit 1 of an offset printing press, for example a sheet-fed offset rotary printing press in aggregate and in-line design, a coupling connection to the im Rubber cylinder 6 arranged actuator, in particular electric motor 11, dissolved and / or an engagement opening or a driving profile, in particular hexagon socket 20, for manual rotary drive of a tensioning shaft 9 are released.

The transmission element, in particular the push rod 17, can preferably be displaced by an inserted tool, in particular an Allen tool. The tool preferably displaces the push rod 17 accommodated within a clamping screw 13 against the spring force of a compression spring 18 . The tool moves the pressure rod 17, which is mounted or guided within the clamping screw 13, radially towards the rubber cylinder 6 on its axis of rotation, with a coupling connection to the actuator arranged inside the rubber cylinder 6, in particular the electric motor 11 or angle planetary gear 12, being released at the same time. The clamping screw 13, which is adapted to a tool and has the driving profile, in particular the hexagon socket 20, can then be turned manually by the tool. When the clamping screw 13 is rotated, via transmission means or coupling elements, for example the sliding blocks 15A, 15B sliding on the threaded plate 14, via the clamping shaft 9 connected couplers 16A, 16B, causing rotation of the corresponding tensioning shaft 9 in the desired direction. The other clamping screw 13 can be turned manually in the same way.

The actuators arranged in the blanket cylinder 6 , in particular electric motors 11 , can each be inserted or used for automated tensioning, retensioning and/or releasing the blanket on the blanket cylinder 6 . The blanket change can be preselected by an operator, for example at the control station via the machine control, with the machine positioning one, several or all blanket cylinders 6 and/or one, several or all blankets already relaxed by a motor. In particular, the motor driver for controlling the electric motor or motors 11 is connected to the control device or the machine control and commands for tensioning or loosening the rubber blanket are to be input or input by the operator to the control device or the machine control. For example, the control station, a control panel or a mobile control unit can be used for input. The clamping and/or loosening of blankets on several or all blanket cylinders 6 in the printing units 1 can be coordinated in particular by the machine control. The corresponding old rubber blankets can be removed by the operator or operators and the new rubber blankets can be inserted in particular without tools. The rubber blankets can also be pre-tensioned without tools. After the new rubber blankets have been used, these rubber blankets can be tensioned automatically.

Furthermore, the motor driver for controlling the electric motor or motors 11 is connected to the control device or the machine control in such a way that intervals for retensioning the rubber blanket or blankets can be stored in the control device or the machine control. Specified intervals can result from time specifications or the number of revolutions or arcs. Alternatively or additionally, via the control device or the Machine control but also commands for retensioning the blanket or blankets are given by the operator. Retensioning of the rubber blanket or blankets can be coordinated at suitable times by the control device or the machine control. For example, retensioning can take place between print jobs and/or without stopping the machine. By using the controllable or remotely controllable actuators, in particular electric motors 11, in one or all blanket cylinders 6 for the rotary drive of continuous tensioning shafts 9, the blanket or blankets are automatically retensioned according to a command from an operator or according to the specified intervals. The tightening can be carried out independently of the angular position of a blanket cylinder 6, with no protection must be operated.

List of reference numbers used

1

printing unit

2

Inking or inking and dampening unit

3

pressure cylinder

4

transfer drum

5

gripper systems

6

rubber cylinder

7

plate cylinder

8th

cylinder channel

9

expansion shaft

10

mount

11

electric motor

12

Angular planetary gear

13

clamping screw

14

threaded plate

15A, 15B

sliding block

16A, 16B

paddock

17

push rod

18

compression spring

19

Lock with spline profile

20

Allen key

21

inductive sensor

S1.1

Limit switch side 1 in released direction

S1.2

Limit switch side 1 in the clamped direction

S2.1

Limit switch side 2 in released direction

S2.2

Limit switch side 2 in the clamped direction

Claims (15)

1. Blanket cylinder (6) for a printing unit (1) of a printing press for carrying at least one rubber blanket,

   wherein the blanket cylinder (6) has a continuous tensioning shaft (9) for clamping and tensioning a leading edge of the rubber blanket and a continuous tensioning shaft (9) for clamping and tensioning a trailing edge of the rubber blanket,

   wherein the continuous tensioning shaft (9) for clamping and tensioning the leading edge of the rubber blanket and the continuous tensioning shaft (9) for clamping and tensioning the trailing edge of the rubber blanket are accommodated in such a way as to be rotatable about their axes of rotation in order to tension the rubber blanket and

   wherein drive means are provided for rotationally driving the continuous tensioning shaft (9) for clamping and tensioning the leading edge of the rubber blanket and the continuous tensioning shaft (9) for clamping and tensioning the trailing edge of the rubber blanket,

   wherein the drive means comprise at least one controllable actuator (11), arranged in the blanket cylinder (6), for driving the continuous tensioning shaft (9) for clamping and tensioning the leading edge of the rubber blanket and/or the continuous tensioning shaft (9) for clamping and tensioning the trailing edge of the rubber blanket,

   and wherein the blanket cylinder (6) has at least one cylinder channel (8) for accommodating the tensioning shafts (9),

   characterized

   in that the at least one actuator (11) is provided in the blanket cylinder (6) as an electric motor (11) for the tensioning shaft (9) for clamping and tensioning the leading edge of the rubber blanket and/or as an electric motor (11) for the tensioning shaft (9) for clamping and tensioning the trailing edge of the rubber blanket,

   and in that the at least one actuator (11) for driving the one continuous tensioning shaft (9) for clamping and tensioning the leading edge of the rubber blanket and/or the one continuous tensioning shaft (9) for clamping and tensioning the trailing edge of the rubber blanket is arranged at least partially outside of the cylinder channel (8) in a cylinder body of the blanket cylinder (6).
2. Blanket cylinder (6) according to claim 1, wherein the tensioning shaft (9) for clamping and tensioning the leading edge of the rubber blanket and/or the tensioning shaft (9) for clamping and tensioning the trailing edge of the rubber blanket has an attachment means (10) for the rubber blanket, the format width of the attachment means corresponding in particular to the maximum width to be processed.
3. Blanket cylinder (6) according to claim 1 or 2, wherein one or each actuator (11) actuates a tensioning screw (13) oriented radially in relation to the blanket cylinder (6), which tensioning screw, when rotated, brings about a rotational movement of an associated tensioning shaft (9) by way of gear means (14, 15A, 15B, 16A, 16B).
4. Blanket cylinder (6) according to claim 1, 2 or 3, wherein the drive means have in each case a coupling connection (13, 19) between an actuator (11) and an associated tensioning shaft (9), which coupling connection can in particular be released manually and/or by means of a tool.
5. Blanket cylinder (6) according to claim 1, 2, 3 or 4, wherein a tensioning screw (13), which passes through a threaded plate (14) and accommodates a push rod (17) in a movable manner in its interior, can be driven in rotation by an actuator (11).
6. Blanket cylinder (6) according to claim 1, 2, 3, 4 or 5, wherein, in the case of a rotatable tensioning screw (13), an engagement opening (20) for a tool can be exposed and/or a connection to the actuator (11) can be released by moving a pressure rod (17), which is accommodated within the tensioning screw (13), counter to a compression spring (18).
7. Blanket cylinder (6) according to claim 1, 2, 3, 4, 5 or 6, wherein the actuator provided for each tensioning shaft (9) is an electric motor (11) with a rotor, which is arranged parallel to the axis of rotation of the blanket cylinder (6), and/or a gear mechanism or angular planetary gear mechanism (12) .
8. Blanket cylinder (6) according to claim 1, 2, 3, 4, 5, 6 or 7, wherein in each case a tensioning screw (13) having an external thread is provided for each tensioning shaft (9), wherein in each case a threaded plate (14) having an internal thread can be moved radially relative to the blanket cylinder (6) by a tensioning screw (13) when the tensioning screw (13) is rotated, and, as a threaded plate (14) is moved, a respective tensioning shaft (9) can be moved about its axis of rotation by way of gear means (15A, 15B, 16A, 16B) provided on both sides of the threaded plate (14).
9. Blanket cylinder (6) according to claim 1, 2, 3, 4, 5, 6, 7 or 8, wherein the continuous tensioning shaft (9) for clamping and tensioning the leading edge of the rubber blanket and/or the continuous tensioning shaft (9) for clamping and tensioning the trailing edge of the rubber blanket is formed in one piece and/or in format width and/or with a diameter that remains constant over the format width of the blanket cylinder (6) .
10. Blanket cylinder (6) according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9, wherein a motor driver for the actuator (s) (11) is located outside of the blanket cylinder (6).
11. Blanket cylinder (6) according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, wherein a control device or machine controller is provided, which coordinatively controls a rotational drive of the blanket cylinder (6) and the actuator(s) (11) of the blanket cylinder (6).
12. Blanket cylinder (6) according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, wherein a sensor (21) is provided for monitoring the movement of the tensioning shaft (9) for clamping and tensioning the leading edge of the rubber blanket.
13. Method for handling a rubber blanket on a blanket cylinder (6) in a printing unit (1) of a printing press,

    wherein the blanket cylinder (6) has a continuous tensioning shaft (9) for clamping and tensioning a leading edge of the rubber blanket and a continuous tensioning shaft (9) for clamping and tensioning a trailing edge of the rubber blanket,

    wherein the continuous tensioning shaft (9) for clamping and tensioning the leading edge of the rubber blanket and the continuous tensioning shaft (9) for clamping and tensioning the trailing edge of the rubber blanket rotate about their axes of rotation in order to tension the rubber blanket, and

    wherein drive means rotationally drive the continuous tensioning shaft (9) for clamping and tensioning the leading edge of the rubber blanket and the continuous tensioning shaft (9) for clamping and tensioning the trailing edge of the rubber blanket,

    wherein an actuator (11), arranged in the blanket cylinder (6), for driving the continuous tensioning shaft (9) for clamping and tensioning the leading edge of the rubber blanket and/or the continuous tensioning shaft (9) for clamping and tensioning the trailing edge of the rubber blanket is controlled as the drive means for one or each tensioning shaft (9),

    characterized in that

    a coupling connection (19, 13) to the actuator (11) arranged in the blanket cylinder (6) is released by moving a gear element (17), and the rubber blanket is manually tensioned, re-tensioned or loosened.
14. Method according to claim 13, wherein an operator preselects the rubber blanket change, wherein the machine positions the blanket cylinder (6) and/or already releases the tension of the rubber blanket by means of a motor.
15. Method according to claim 13 or 14, wherein the tensioning shaft (9) for clamping and tensioning the leading edge of the rubber blanket is pretensioned by one or more revolutions with the new rubber blanket attached.

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