Device for tensioning an arcuate roller cover about a roller

Abstract

The device (2) for tensioning the roller cover around the roller (10) has a pair of tensioning rails (11, 12) and has multiple identical tensioning units (4) arranged on a common swing beam (12), whose sub-rails (44) together form the second tensioning rail (12) of the tensioning rail pair and each includes a first locking member (50) configured for the first tensioning rail (11) and a second locking member (58) configured for the corresponding sub-rail (44), wherein the locking members (50, 58) can optionally fix or release the roller cover.

Description

Technical Field

[0001] The present invention relates to a device for tensioning an arcuate roller cover around the outer surface of a rotatable roller. Background Technology

[0002] An apparatus for adjusting and tensioning a flexible printing plate on a plate cylinder of a rotary printing press is known from EP0401500A2. In this apparatus, a pair of tensioning rails are oriented parallel to the axis of rotation of the plate cylinder. The tensioning rails extend almost the entire length of the plate cylinder and are pivotally supported on the cylinder body by levers. Therefore, angular errors in the printed image can be corrected by slightly moving the printing plate on the plate cylinder.

[0003] In known devices, manually tensioning the roller cover onto the roller is cumbersome. Typically, the cover partially slips out of the pair of first tensioning rails before being fully engaged with the second tensioning rail and secured by tension. This is particularly inconvenient with wide roller covers, requiring two people to lift them.

[0004] Pressing the roller cover into an undersized receiving groove requires considerable force, and removing the roller cover is difficult. Furthermore, the required force significantly increases the risk of damaging the roller, especially when a hammer is used as an auxiliary tool.

[0005] To achieve the desired adaptation, DE9318599U1 proposes a targeted tilting of the printing plate on the plate cylinder. For this purpose, a pair of successive tensioning rails are arranged in the circumferential direction. One of the tensioning rails is housed in the plate cylinder in the form of a trapezoidal four-hinge. The four-hinge is connected to the centered second tensioning rail via levers and hinges in such a way that axial movement of the first rail simultaneously causes its pivoting.

[0006] To prevent the printing plate from accidentally slipping off the tension rail, US4831931A proposes clamping elements. These clamping elements are suitable for clamping the printing plate against the tension rail in the area it is inserted into.

[0007] The indentation stretching of the printing plate can be compensated using a split tensioning rail as described in DE102010045036A1. For this purpose, the tensioning rail is divided into multiple segments in the axial direction, allowing tension to be applied to each segment individually. Continuously attaching the roller cover to the split rail and immediately tensioning it facilitates the tensioning process, but it can lead to undesirable uneven stretching of the roller cover. In particular, the sequence of each tensioning process affects this stretching and thus the printed image. Summary of the Invention

[0008] Therefore, the object of the present invention is to provide an improved device relative to the prior art, which overcomes at least one of the pointed disadvantages of the prior art.

[0009] This task is solved using an apparatus / method for tensioning at least one substantially arcuate printing template or plate substantially around the outer surface of a printing cylinder, wherein the printing cylinder is rotatably supported about its axial axis of rotation. The apparatus has...

[0010] • At least one first rail, substantially parallel to the axis of rotation of the printing cylinder, is disposed on the outer surface of the printing cylinder.

[0011] • At least one second rail, substantially parallel to the axis of rotation of the printing cylinder, disposed on the outer surface of the printing cylinder and formed by at least two sub-rails, wherein,

[0012] The first and second tracks each have at least one side recess for form-fittingly accommodating at least one printing template or at least one printing plate.

[0013] • At least one first track and at least one second track have a variable spacing between them along the circumferential direction of the printing cylinder.

[0014] • At least two tensioning units spaced apart from each other in the direction of the rotation axis of the printing cylinder, each having at least one slide that is substantially movable in the circumferential direction of the printing cylinder, a driver that is drivenly connected to at least one slide, and a secondary rail formed by the slide forming a second rail.

[0015] At least one locking element is disposed opposite to at least one sub-rail of at least one second rail, wherein the at least one locking element optionally has an open position and a closed position with respect to the at least one configured sub-rail, and together with the at least one configured sub-rail, forms a closable receiving portion.

[0016] The feature is that at least one locking element is formed by a lever with two legs that can rotate about an axis, wherein the axis extends substantially radially about the printing cylinder and the two legs of the lever together open a plane that is substantially perpendicular to the axis of the locking element.

[0017] To this end, a tensioning device is provided for tensioning a roller cover to the outer surface of a rotatable roller, wherein the roller may be a printing cylinder and the roller cover may be a printing template. The tensioning device has a pair of tensioning rails on the outer surface of the roller parallel to the axis of rotation of the roller. The tensioning rails are correspondingly formed with recessed side grooves, into which the front or rear edge of the roller cover can be hooked.

[0018] The second tensioning rail in a pair consists of multiple similar sub-rails in its longitudinal direction. Each of these sub-rails is mounted on a slide of a tensioning unit. The slide is movable substantially circumferentially with respect to a sub-rail. Here, the position of the slide determines the distance between its sub-rail and the first clamping rail in the pair, and thus determines the tension of the roller cover. For this purpose, each tensioning unit is equipped with an individual driver acting on the corresponding slide.

[0019] The tensioning device includes a locking member configured for the second tensioning rail. The locking member is arranged relative to the second tensioning rail such that, when the roller cover is not tensioned, the locking member secures the roller cover in its closed arrangement to prevent it from accidentally slipping out of the receiving portion of the rail, and releases the roller cover relative to the corresponding rail in its open arrangement.

[0020] The locking element is designed as a lever with a rotation axis, allowing the lever leg to move in a plane oriented substantially tangentially to the roller surface. Particularly advantageously, the locking element is mounted on a slide of a tensioning unit and configured for the tensioning unit's rails. Therefore, the fixing or releasing of the roller cover is unaffected by the position of the tensioning slide. This prevents accidental release of the roller cover during premature release.

[0021] Preferably, each of these individual tensioning actuators is configured with a common switch. Therefore, the tensioning unit can be activated individually. Thus, for example, when using a narrow roller cover, an unnecessary tensioning unit can be shut off. Furthermore, by shutting off individual tensioning units when needed, wide roller covers can be selectively stretched or twisted unevenly.

[0022] Advantageously, multiple identical tensioning units are arranged on a common swing beam having a swing axis substantially relative to the radial direction of the roll. Angular errors in the roll cover can be corrected by the swinging of this beam.

[0023] Preferably, the oscillating beam is equipped with a feed device featuring a controllable servo drive. This allows for automatic correction of angular errors in the roller cover without manual intervention. Particularly advantageous is the use of curved rollers rolling on the curved edge for directional control of the oscillating motion. By designing the curve, the desired force curve for the oscillation can be adjusted.

[0024] The feeding device preferably includes a push rod that is guided into the roller via a hollow shaft. In this way, motion-sensitive drive elements can be positioned outside the roller. Attached Figure Description

[0025] The invention will then be further illustrated with reference to the accompanying drawings, which cover all details not further mentioned in the specification, and with reference to embodiments. (See the drawings.)

[0026] Figure 1A simplified perspective view of a printing cylinder with a tensioning device is shown.

[0027] Figure 2 A simplified perspective detail of the feed mechanism used to oscillate the tensioning device is shown.

[0028] Figure 3 A simplified detailed diagram of the feed mechanism used to oscillate the tensioning device is shown;

[0029] Figure 4 Simplified diagrams of the tensioning unit under different states are shown;

[0030] Figure 5 A simplified perspective detail of the tensioning device is shown;

[0031] Figure 6 A simplified perspective detail of the tensioning unit is shown;

[0032] Figure 7 This illustrates the switching logic of the locking element of the tensioning device.

[0033] 1. A device for tensioning at least one substantially arcuate printing template or printing plate substantially around the outer surface (103) of a printing cylinder (10), wherein the printing cylinder (10) is rotatably supported about its axial axis of rotation (100), said device having

[0034] • At least one first rail (11) disposed on the outer surface of the printing cylinder (10), substantially parallel to the axis of rotation (100) of the printing cylinder (10).

[0035] • At least one second rail (12) formed by at least two sub-rails (44) disposed on the outer surface of the printing cylinder (10) substantially parallel to the axis of rotation (100) of the printing cylinder (10), wherein,

[0036] The first track (11) and the second track (12) each have at least one side recess (45) for form-fittingly accommodating at least one printing template or at least one printing plate.

[0037] The at least one first track (11) and the at least one second track (12) have a variable spacing (70) between them along the circumferential direction of the printing cylinder (10).

[0038] • At least two tensioning units (4) spaced apart from each other in the direction of the rotation axis (100) of the printing cylinder (10), each having at least one slide (40) that is substantially movable in the circumferential direction of the printing cylinder (10), a driver (42) drivenly connected to at least one slide (40), and a secondary rail (44) formed by the second rail (12) disposed on the slide (40).

[0039] At least one locking element is disposed opposite to at least one sub-rail (44) of the at least one second rail (12), wherein the at least one locking element optionally has an open position (300) and a closed position (301) with respect to the at least one configured sub-rail (44), and together with the at least one configured sub-rail (44) forms a closable receiving portion.

[0040] The feature is that the at least one locking member is formed by a lever (53) having two legs (61, 62) rotatable about an axis (102), wherein the axis (102) extends substantially radially about the printing cylinder (10) and the two legs (61, 62) of the lever (53) together open a plane that is substantially perpendicular to the axis (102) of the locking member.

[0041] 2. The apparatus according to embodiment 1, characterized in that each of the at least two tensioning units (4) has a separate switch (38) configured for a corresponding at least one driver (42), and the group of the corresponding at least two tensioning units (4) has another common switch (39), wherein each of the separate switches (38) of the at least two tensioning units (4) of the common group is connected to at least one common switch (39) of the common group in the form of a circuit.

[0042] 3. The apparatus according to embodiment 1, characterized in that at least one of the at least two tensioning units (4) has at least one locking element configured for at least one rail (44) of the tensioning unit (4).

[0043] 4. The apparatus according to embodiment 2, characterized in that at least one of the at least two tensioning units (4) has at least one locking element configured for at least one rail (44) of the tensioning unit (4).

[0044] 5. The apparatus according to embodiment 1, characterized in that the apparatus further comprises a crossbeam (13) extending substantially parallel to the rotation axis (100) of the printing cylinder (10) and capable of swinging at least slightly relative to the printing cylinder (10) about an oscillation axis (101), and the at least two tensioning units (4) are provided on the crossbeam, wherein the oscillation axis (101) of the crossbeam (13) extends orthogonally to the rotation axis (100) of the printing cylinder (10).

[0045] 6. The apparatus according to embodiment 4, characterized in that the apparatus further comprises a crossbeam (13) extending substantially parallel to the rotation axis (100) of the printing cylinder (10) and capable of swinging at least slightly relative to the printing cylinder (10) about an oscillation axis (101), and the at least two tensioning units (4) are provided on the crossbeam, wherein the oscillation axis (101) of the crossbeam (13) extends orthogonally to the rotation axis (100) of the printing cylinder (10).

[0046] 7. The apparatus according to embodiment 6 is characterized in that at least one feed device (3) with at least one controllable servo driver (34) is provided for at least one crossbeam (13), wherein the at least one controllable servo driver (34) is connected to the control device (6) via at least one data line (60) for exchanging signals.

[0047] 8. The apparatus according to embodiment 6, characterized in that the crossbeam (13) has at least one curved edge (30), and the feeding device (3) has at least one curved roller (31), wherein the curved roller (31) rolls on the at least one curved edge (30).

[0048] 9. The apparatus according to embodiment 7, characterized in that the crossbeam (13) has at least one curved edge (30), and the feeding device (3) has at least one curved roller (31), wherein the curved roller (31) rolls on the at least one curved edge (30).

[0049] 10. The apparatus according to any one of embodiments 5 to 9, characterized in that the controllable feeding device (3) includes at least one push rod (36), wherein the at least one push rod (36) is arranged collinearly with the rotation axis (100) of the printing cylinder (10) and extends through the hollow shaft (16) of the printing cylinder (10). Detailed Implementation

[0050] exist Figure 1 The image shows a printing cylinder 1 with a tensioning device 2 according to the invention. The outer surface 103 of the central cylinder 10 is penetrated by a channel 17. This channel 17 extends in the axial direction y, parallel to the rotation axis 100 of the printing cylinder 1, and accommodates the tensioning device 2. Figure 3 As shown, the printing cylinder is supported in the frame 5 by shoulders 16 provided on both sides of the central cylinder 10.

[0051] The first tensioning rail 11 and the second tensioning rail 12 together form the tensioning rail pair of the tensioning device 2. The tensioning rails 11 and 12 are axially oriented parallel to each other on the outer surface 103 of the roller 10. These two tensioning rails have a variable spacing 70 between them in the circumferential direction. The first tensioning rail 11 and the second tensioning rail 12 each form a side recess 45, which is in the form of a groove opening in the circumferential direction of the roller 10. The openings of these two grooves face each other. The printing template can be hooked into the groove at its front or rear edge. By narrowing the spacing 70 between the two tensioning rails 11 and 12, the hooked printing template is tensioned and thus fixed to the roller 10.

[0052] Tensioning rails are mounted on a crossbeam 13 of the tensioning device 2. This crossbeam 13 extends axially in the channel 17 of the printing cylinder 1. The crossbeam is mounted to swing about an axis 101 extending radially about the printing cylinder 1. The slight swing 202 of the tensioning rails 11, 12 about the radial axis 101 allows for correction of the angular position of the printed pattern. For this correction, a feed device 3 is provided. For this purpose, the feed device 3 includes a controllable positioning actuator 34. This positioning actuator 34 communicates with the control device 6 via a data line 60.

[0053] The positioning actuator 34 acts on the swingable beam 13 of the tensioning device 2 via a transmission mechanism that passes axially through the hollow shaft 16 of the printing cylinder 1. For this purpose, the screw drive 35 of the feed device 3 connects the positioning actuator 34 to a push rod 36 that runs axially within the hollow shaft 16 of the printing cylinder 1. An arm 37 of the feed device 3, connected to the push rod 36, passes through the end face 104 of the central cylinder 10 and acts into the channel 17 of the printing cylinder 1. The arm 37 is supported in the channel 17 by means of a linear guide 33. The linear guide 33 is oriented parallel to the rotation axis 100 of the printing cylinder 1 and allows the arm 37 to perform a linear axial movement 201. A curved roller 31 is mounted on the end of the arm 37 that extends into the channel 17. The curved roller 31 engages with the curved edge 30 of the swing beam 13. The beam 13 is supported on the channel 17 by a first pressure spring 32 such that the beam always rests against the curved roller 31 of the feed device 3. The linear movement 201 of the arm 37 causes its curved roller 31 to roll on the curved edge 30 of the crossbeam 13, and thus causes the crossbeam to swing about its swing axis 101 202.

[0054] The second tensioning rail 12 consists of multiple sub-rails 44 arranged sequentially along the axial direction y. Each of these sub-rails 44 is part of one of multiple similar tensioning units 4. The structure of this tensioning unit is as follows: Figures 4 to 6As shown in the diagram, the tensioning unit 4 includes a tensioning slide 40. The tensioning slide 40 is housed on the swing beam 13 of the tensioning device 2 via a linear guide 43 and carries one of the branch rails 44. The linear guide 43 is oriented substantially radially about the central roller 10 of the printing roller 1 and determines the direction of the linear tensioning movement 200. For this purpose, the linear guide includes two guide rails that are parallel to each other.

[0055] The tensioning slide 40 of the tensioning unit 4 is operated by a separate drive. This drive moves the slide between two end positions. Figure 4 Figure a shows the end position in which the printing template is tensioned. A second pressure spring 41 holds the tensioning slide 40 in this end position and applies tension to the guide rail 44. To release the printing template, the second pressure spring 41 is over-adjusted by the pneumatic cylinder 42, thereby positioning the tensioning slide 40 as shown in Figure a. Figure 4 The other end position is shown in bd. Each tensioning unit 4 has a separate switch 38 for its actuator. In a simple manner, the switch 38 can be a manually operated valve, which is not shown in the figure. In this way, each tensioning unit 4 can be turned on or off. For automatic operation of the tensioning unit 4, the pressure lines of each tensioning unit 4 are as follows: Figure 7 The locations shown are merged into a central pressure line, which includes a mechanically controllable multi-way valve as a common switch 39. The common valve and the individual valves are arranged in relation to each other in the form of a circuit.

[0056] Each tensioning unit 4 includes a first locking member 50 configured for the first tensioning rail 11. The first locking member is disposed opposite to a groove in the first tensioning rail 11 that accommodates a printing template and is designed to release this groove for template replacement and to lock it for template tensioning. For this purpose, the first locking member 50 is mounted on the swing beam 13 of the tensioning device 2 and can occupy… Figure 4 The closed position 301 shown in ac and Figure 4 The opening position is 300 as shown in d.

[0057] The first locking member 50 is constructed as a lever 53 with two legs 61, 62 perpendicular to each other. This first locking member is pivotable about an axis about the radial direction of the printing cylinder and is housed in a rotary bearing 54 of the tension slide 40. In its closed position 301, the first leg 61 of the first locking member 50 is oriented parallel to the first tension rail 11. The opening width 71 between the first tension rail 11 and the first locking member 50 is small, thus reliably preventing the inserted printing template from slipping out. Here, the second leg 62 points towards the second tension rail 12, and the second contact surface 52 on its rear side is secured by a magnet 55.

[0058] In its open position 301, the second leg 62 of the first locking member 50 is oriented parallel to the first tension rail. The opening width 71 is larger than in the closed position 301, allowing for easy insertion and removal of the printing template. Here, the first leg 61 points towards the second tension rail 12 and is secured by a magnet 55 via a first contact surface 51 located on its back side. For manipulating the first locking member 50, a handle 57 is provided, mounted on a lever 53l via a rotary bearing 54.

[0059] The second locking element 58 of each tensioning unit 4 is disposed on the corresponding tensioning slide 40 and is opposite to the receiving groove of the configured rail. The functional principle and structure of the second locking element are the same as those of the first locking element 50 and therefore will not be described further.

[0060] The tensioning device 2 has multiple identical tensioning units 4 as described above, which are arranged on a common swing beam 13.

[0061] exist Figure 4 The diagram shows the various states of a single tensioning unit 4 during the replacement and tensioning of the printing template. The printing template itself is not shown. Figure 4 Starting from the tensioned state, the template is tensioned and the two locking elements 50, 58 are fixed in their respective closed positions 301. If a separate valve opens, the pneumatic cylinder 42 over-adjusts the second pressure spring 41 when the common multi-way valve opens, thereby moving the tension slide 40 to... Figure 4 In the end position shown in b, the distance between tension rails 11 and 12 is increased, causing the inserted printing template to loosen. According to... Figure 4 c opens the second locking member 58, releasing the first edge of the printing template, thereby allowing the printing template to be released from the printing cylinder. If the first locking member is also additionally in its open position 300, as... Figure 4 As shown in d, the printing template can then be completely removed. The template installation and tensioning are performed in reverse order.

[0062] Figure Labels

[0063] 1 printing cylinder 44-section

[0064] 2 tensioning devices 45-degree side concave

[0065] 3. Feeding device, swing 50, first locking element

[0066] 4 tensioning unit 51 first contact surface

[0067] 5 Frame 52 Second Contact Surface

[0068] 6 control devices 53 levers

[0069] 10 rollers, 54 rotary bearings

[0070] 11 First track 55 magnet

[0071] 12 Second rail 56 Fixing part

[0072] 13 Crossbeams 57 Handles

[0073] 15 Rotary bearing 58 Second locking element

[0074] 16 Hollow Shaft 60 Data Cable

[0075] 17 Channel 61 First Leg

[0076] 20 Cover plate 62 Second leg

[0077] 30 curved edge, 70 spacing

[0078] 31 Curved scroll wheel 71 Opening width

[0079] 32 First pressure spring 100 Rotation axis

[0080] 33 Linear guide device 101 Swing axis

[0081] 34 Positioning driver 102 Rotation axis

[0082] 35 Screw drive 103 outer surface

[0083] 36 push rod 104 end face

[0084] 37-arm 200-degree linear tension motion

[0085] 38 Switch 201 Linear Motion

[0086] 39 Switch group 202 Oscillating motion

[0087] 40 tensioned slide 203 first rotational motion

[0088] 41 Second pressure spring 204 Second rotational motion

[0089] 42 Pneumatic cylinder 300 Open position

[0090] 43 Linear guide device 301 Closed position

Claims

1. A device for tensioning at least one substantially arcuate printing template substantially around the outer surface (103) of a printing cylinder (10), wherein, The printing cylinder (10) is rotatably supported about its axial rotation axis (100), and the device has • At least one first rail (11) disposed on the outer surface of the printing cylinder (10), substantially parallel to the axis of rotation (100) of the printing cylinder (10). • At least one second rail (12) formed by at least two sub-rails (44) disposed on the outer surface of the printing cylinder (10) substantially parallel to the axis of rotation (100) of the printing cylinder (10), wherein, The first track (11) and the second track (12) each have at least one side recess (45) for form-fittingly accommodating at least one printing template. The at least one first track (11) and the at least one second track (12) have a variable spacing (70) between them along the circumferential direction of the printing cylinder (10). • At least two tensioning units (4) spaced apart from each other in the direction of the rotation axis (100) of the printing cylinder (10), each having at least one slide (40) that is substantially movable in the circumferential direction of the printing cylinder (10), a driver (42) drivenly connected to at least one slide (40), and a secondary rail (44) formed by the second rail (12) disposed on the slide (40). At least one locking element is disposed opposite to at least one sub-rail (44) of the at least one second rail (12), wherein the at least one locking element optionally has an open position (300) and a closed position (301) with respect to the at least one configured sub-rail (44), and together with the at least one configured sub-rail (44) forms a closable receiving portion. The feature is that the at least one locking member is formed by a lever (53) having two legs (61, 62) rotatable about an axis (102), wherein the axis (102) extends substantially radially about the printing cylinder (10) and the two legs (61, 62) of the lever (53) together open a plane that is substantially perpendicular to the axis (102) of the locking member.

2. The apparatus according to claim 1, characterized in that, The at least two tensioning units (4) each have a separate switch (38) configured for at least one corresponding driver (42), and the group of at least two tensioning units (4) each has another common switch (39), wherein each of the separate switches (38) of the at least two tensioning units (4) of the common group is connected to at least one common switch (39) of the common group in the form of a circuit.

3. The apparatus according to claim 1, characterized in that, At least one of the at least two tensioning units (4) has at least one locking element configured for at least one rail (44) of the tensioning unit (4).

4. The apparatus according to claim 2, characterized in that, At least one of the at least two tensioning units (4) has at least one locking element configured for at least one rail (44) of the tensioning unit (4).

5. The apparatus according to claim 1, characterized in that, The device also has a crossbeam (13) that extends substantially parallel to the axis of rotation (100) of the printing cylinder (10) and is capable of swinging at least slightly relative to the printing cylinder (10) about an oscillation axis (101), and the at least two tensioning units (4) are provided on the crossbeam, wherein the oscillation axis (101) of the crossbeam (13) extends orthogonally to the axis of rotation (100) of the printing cylinder (10).

6. The apparatus according to claim 4, characterized in that, The device also has a crossbeam (13) that extends substantially parallel to the axis of rotation (100) of the printing cylinder (10) and is capable of swinging at least slightly relative to the printing cylinder (10) about an oscillation axis (101), and the at least two tensioning units (4) are provided on the crossbeam, wherein the oscillation axis (101) of the crossbeam (13) extends orthogonally to the axis of rotation (100) of the printing cylinder (10).

7. The apparatus according to claim 6, characterized in that, At least one crossbeam (13) is equipped with at least one feed device (3) having at least one controllable servo driver (34), wherein the at least one controllable servo driver (34) is connected to the control device (6) via at least one data line (60) for exchanging signals.

8. The apparatus according to claim 6, characterized in that, The crossbeam (13) has at least one curved edge (30), and the feeding device (3) has at least one curved roller (31), wherein the curved roller (31) rolls on the at least one curved edge (30).

9. The apparatus according to claim 7, characterized in that, The crossbeam (13) has at least one curved edge (30), and the feeding device (3) has at least one curved roller (31), wherein the curved roller (31) rolls on the at least one curved edge (30).

10. The apparatus according to any one of claims 5 to 9, characterized in that, The controllable feeding device (3) includes at least one push rod (36), wherein the at least one push rod (36) is arranged collinearly with the rotation axis (100) of the printing cylinder (10) and extends through the hollow shaft (16) of the printing cylinder (10).

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