METHOD FOR AUTOMATICALLY EXCHANGING A SLEEVE OF A PRINTING TOOL

Abstract

A method is provided for automatically exchanging a sleeve (18a) of a printing tool (14, 16, 18, 22, 24) mounted in a printing machine (12), in particular a flexographic printing machine, by means of a printing tool handling unit (28) comprising a coupling interface (36). In one step of the method the printing tool handling unit (28) is temporarily coupled to a coupling interface (46) located at the end of a shaft (54, 56, 58, 60) of the printing tool (14, 16, 18, 22, 24) with its coupling interface (36). In a further step, the printing tool handling unit (28) transports the printing tool (14, 16, 18, 22, 24) to a separation unit (78) comprising at least one clamping device (80, 82, 84) and places the printing tool (14, 16, 18, 22, 24) in the clamping device (80) of the separation unit (78). The printing tool (14, 16, 18, 22, 24), in particular a sleeve (18a) of the printing tool (14, 16, 18, 22, 24), is clamped by the clamping device (80), and the printing tool handling unit (28) separates the shaft (54, 56, 58, 60) from the sleeve (18a) by pulling the shaft (54, 56, 58, 60) out of the sleeve (18a) while the sleeve (18a) is clamped in the clamping device (80).

Claims

1. A method for automatically exchanging a sleeve of a printing tool mounted in a printing machine, in particular a flexographic printing machine, using a printing tool handling unit comprising a coupling interface, the method comprising: temporarily coupling the printing tool handling unit to a coupling interface of the printing tool located at an end of a shaft of the printing tool with the coupling interface, transporting, by the printing tool handling unit transports, the printing tool to a separation unit comprising at least one clamping device and placing, by the printing tool handling unit, the printing tool in the clamping device of the separation unit, clamping a sleeve of the printing tool, by the clamping device, and separating, by the printing tool handling unit, the shaft from the sleeve by pulling the shaft out of the sleeve while the sleeve is clamped in the clamping device.

2. The method according to claim 1, wherein the printing tool is removed from the printing machine by moving the printing tool along an axis of rotation of the printing tool.

3. The method according to claim 1, wherein the shaft is separated from the sleeve by pulling the shaft out of the sleeve along an axis of rotation of the printing tool.

4. The method according to claim 1, wherein the coupling interface of the printing tool handling unit is moved concentrically to the coupling interface of the printing tool when connecting to the coupling interface of the printing tool.

5. The method according to claim 1, wherein an adapter is interposed between the shaft of the printing tool and the sleeve, and wherein the adapter is separated from the sleeve together with the shaft and afterwards an assembly comprising the adapter and the shaft is moved by the printing tool handling unit to a further clamping device in which the adapter is clamped and the shaft is withdrawn from the adapter.

6. The method according to claim 5, wherein after separating the adapter and the shaft, the shaft is moved to another clamping device and clamped therein.

7. The method according to claim 6, wherein after clamping the shaft in the clamping device, the shaft is separated from the printing tool handling unit.

8. The method according to claim 1, wherein the clamping device comprises at least two clamping jaws, wherein the printing tool is surrounded by the clamping jaws when the printing tool is inserted in the separation unit, and wherein the clamping jaws are moved towards the printing tool in a radial direction in order to clamp the sleeve of the printing tool.

9. The method according to claim 5, wherein the separation of the sleeve and/or the adapter from the shaft is performed in a fully automatic manner by the printing tool handling unit.

10. The method according to claim 1, wherein the shaft of the printing tool is supported in the printing machine in a double sided manner, and wherein a support of the printing tool is removed on one side in order to access the printing tool with the printing tool handling unit-R.

Description

[0039] FIG. 1 schematically shows a printing assembly according to the invention comprising a printing machine with printing tools according to the invention, wherein the printing machine is in an operational state,

[0040] FIG. 2 schematically shows the printing machine of the printing assembly of FIG. 1, wherein the printing machine is in a service state,

[0041] FIG. 3 schematically shows the printing machine of FIG. 2 in a top view,

[0042] FIG. 4 shows a detail IV of the end effector of a printing tool handling unit of the printing assembly of FIG. 1 in a partially sectional view,

[0043] FIG. 5 shows a detail of the printing tools of the printing machine of FIG. 3,

[0044] FIG. 6 shows an exemplary one of the printing tools of the printing machine of FIGS. 2 and 3 being coupled with the printing tool handling unit of the printing assembly of FIG. 1,

[0045] FIG. 7 shows a detail VII of two of the printing tools of the printing machine of FIG. 3,

[0046] FIG. 8 shows a detail VIII of two of the printing tools of the printing machine of FIG. 3, and

[0047] FIGS. 9 to 18 illustrate a procedure during which a printing tool of the printing machine of FIG. 3 is withdrawn from the printing machine.

[0048] FIG. 1 shows a printing assembly 10.

[0049] It comprises a printing machine 12 which is a flexographic printing machine in the example shown in the Figures.

[0050] The printing machine 12 has a blade beam 14, which is equipped with an ink chamber, an anilox roll 16, a printing cylinder 18 and a central impression cylinder 20.

[0051] Furthermore, the printing machines 12 comprises a guide roller 22 and a pressure roller 24.

[0052] The blade beam 14, the anilox roll 16, the printing cylinder 18, the guide roller 22 and the pressure roller 24 are printing tools.

[0053] These printing tools 14, 16, 18, 22, 24 are used for printing ink on a substrate 26.

[0054] To this end the substrate 26 travels around the guide roller 22 and the central impression cylinder 20 on which it is pressed by the pressure roller 24. The travelling direction of the substrate 26 and the corresponding directions of rotation are indicated by arrows.

[0055] As has been explained before, the blade beam 14 comprises an ink chamber. The ink provided therein is applied to the anilox roll 16 from which it is transferred to a printing plate mounted on the printing cylinder 18. The printing plate comprises a negative of the pattern to be printed on the substrate 26.

[0056] Also for these printing tools the directions of rotation are indicated by arrows.

[0057] The printing assembly 10 additionally comprises a printing tool handling unit 28 which is configured for automatically withdrawing the printing tools 14, 16, 18, 22, 24 from the printing machine 12 and for automatically inserting the printing tools 14, 16, 18, 22, 24 into the printing machine 12.

[0058] In the example shown the printing tool handling unit 28 comprises an industrial robot 30 having a robot arm 32.

[0059] An end effector 34 is mounted on an end of the robot arm 32.

[0060] The end effector 34 comprises a coupling interface 36 (cf. FIG. 4) which is configured for at least temporarily coupling one of the printing tools 14, 16, 18, 22, 24 to the printing tool handling unit 28.

[0061] The coupling interface 36 comprises a contact surface 38 which corresponds to the shell surface of a truncated cone.

[0062] In the example shown the contact surface 38 is a portion of an inner surface of an opening 40 provided on the end effector 34.

[0063] The coupling interface 36 also comprises a securing means 42 comprising two securing claws 43.

[0064] The securing means 42 is configured for at least temporarily securing one of the printing tools 14, 16, 18, 22, 24 at the printing tool handling unit 28.

[0065] To this end an actuation rod 44 is provided on the end effector 34 which interacts with the securing claws 43.

[0066] The actuation rod 44 is movable along a direction 44a.

[0067] Consequently, the actuation rod 44 may be provided in a securing position. In this position the securing claws 43 are held in a respective securing position (cf. FIGS. 4 and 6).

[0068] Alternatively, the actuation rod 44 may be moved into a release position. In the representation of FIG. 4 this position is shifted to the left as indicated by a dotted line.

[0069] In this position the securing claws 43 are also in a respective release position. Compared to the representation in FIG. 4, the left end of the upper securing claw 43 is slightly moved downwards and the left end of the lower securing claw 43 is slightly moved upwards.

[0070] More details concerning the coupling interface 36 will be explained below in connection with the procedure of exchanging one of the printing tools 14, 16, 18, 22, 24.

[0071] Each of the printing tools 14, 16, 18, 22, 24 comprises a coupling interface 46 for at least temporarily connecting the respective printing tool 14, 16, 18, 22, 24 to the printing tool handling unit 28 (cf. FIG. 5).

[0072] The coupling interfaces 46 are complementary to the coupling interface 36.

[0073] Thus, also the coupling interfaces 46 comprise a frustoconical contact surface 48.

[0074] The contact surface 48 is an outer surface.

[0075] Furthermore, each of the coupling interfaces 46 is equipped with a securing means 50 for temporarily securing the respective printing tool 14, 16, 18, 22, 24 to the printing tool handling unit 28.

[0076] In the example shown in FIG. 5 the securing means 50 comprises a securing collar 51 which is engageable by the securing claws 43 (cf. FIG. 6).

[0077] As far as the guide roller 22 and the pressure roller 24 are concerned, the coupling interface 46 is provided on an interface part 52 which is mounted at a respective end of a shaft 54, 56 of the guide roller 22 and the pressure roller 24 respectively (cf. FIGS. 3 and 5).

[0078] The anilox roll 16 and the printing cylinder 18 are roller assemblies having a shaft 58, 60 respectively. The coupling interface 46 is located at an end of the respective shaft 58, 60 and is formed integrally therewith.

[0079] The anilox roll 16 and the printing cylinder 18 comprise a coupling interface 46 at both ends of the respective shaft 58, 60. The coupling interfaces at the ends of a shafts 58, 60 are substantially identical.

[0080] In the example shown in the Figures, the shafts 58, 60 of the anilox roll 16 and the printing cylinder 18 are connected with respective drive units 62, 64 (cf. FIG. 3). Consequently, the shafts 58, 60 may be designated as driven shafts.

[0081] In more detail, each of the drive units 62, 64 comprises an output shaft 66, 68.

[0082] The output shafts 66, 68 are connected to the corresponding shaft 58, 60 via the coupling interface 46 (cf. FIG. 7). To this end a corresponding coupling interface 70 is provided on the output shafts 66, 68. The coupling interfaces 46, 70 are connectable via a friction fit.

[0083] Consequently, the coupling interface 46 is a combined coupling and drive interface.

[0084] It is noted that the coupling interfaces 46, 70 are only schematically represented in FIG. 7. In reality, the coupling interface 46 is designed as shown in FIG. 5 and the coupling interface 70 is designed in accordance with FIG. 4. In this context the securing means 42, 50 are optional.

[0085] On the respective ends opposing the drive units 62, 64, the anilox roll 16 and the printing cylinder 18 are supported in a frame 72 of the printing machine 12.

[0086] In order to do so, support shafts 74 are rotatorily held in the frame 72 and the shafts 58, 60 are connected to the support shafts 74 via the coupling interface 46 (cf. FIG. 8).

[0087] The support shafts 74 have a corresponding coupling interface 76.

[0088] Again the coupling interfaces 46, 76 are only schematically represented in FIG. 8. In reality, the coupling interface 46 is designed as shown in FIG. 5 and the coupling interface 76 is designed in accordance with FIG. 4. In this context the securing means 42, 50 are optional.

[0089] Consequently, the coupling interface 46 of the anilox roll 16 and the printing cylinder 18 is a combined coupling and support interface.

[0090] The blade beam 14 only comprises one coupling interface 46 which is located at an end of the beam (cf. FIGS. 3 and 5). This coupling interface 46 is also formed integrally with the blade beam 14.

[0091] In the following a printing tool withdrawal procedure will be explained with reference to FIGS. 9 to 18.

[0092] In a first step the printing machine 12 needs to be stopped. This means that an operational state thereof is terminated.

[0093] It is noted that the printing machine 12 represented in the Figures comprises only one printing station being represented by its essential components, i.e. the blade beam 14, the anilox roll 16 and the printing cylinder 18. In printing machines comprising more than one printing stations it may be sufficient to stop only the relevant printing station for withdrawing the corresponding blade beam, anilox roll or printing cylinder.

[0094] If the guide roller 22 or the pressure roller 24 shall be withdrawn from the printing machine 12, usually the entire printing machine 12 is stopped.

[0095] Thereafter, the printing machine 12 is moved to its service state (cf. FIGS. 2, 3 and 9).

[0096] This means that all printing tools 14, 16, 18, 22, 24 are moved to a position where they are spaced apart from each other.

[0097] In case the guide roller 22 or the pressure roller 24 shall be withdrawn from the printing machine 12, the substrate 26 is removed from the printing machine 12.

[0098] Subsequently, a support of the respective printing tool 14, 16, 18, 22, 24 is removed on one side in order to access the printing tool 14, 16, 18, 22, 24 with the printing tool handling unit, more precisely with the end effector. In particular, portions of the frame 72 carrying the support shafts 74 are removed from the remaining portions of the frame 72 in order to render the printing cylinder 18 and the anilox roll 16 accessible by the printing tool handling unit 28 (cf. arrows in FIG. 9).

[0099] In this condition of the printing machine 12 each of the printing tools 14, 16, 18, 22, 24 is accessible by the end effector 34. This is illustrated in FIG. 10 by an end effector 34a to 34e being located adjacent to each of the printing tools 14, 16, 18, 22, 24. It is understood that this is done for illustrative purposes only. The printing assembly 10 comprises one printing tool handing unit 28 having one end effector 34 only.

[0100] In the following, the removing of the printing cylinder 18 will be explained in detail. In this context the printing cylinder 18 can be regarded as an exemplary printing tool. However, removal of the printing tools 14, 16, 22, 24 may be performed in an analogous way.

[0101] Firstly, the printing tool handling unit 28 is temporarily coupled to the coupling interface 46 located at the end of the shaft 60 of the printing tool 18 with its coupling interface 36. More precisely, the printing cylinder 18 is connected to the end effector 34 via the coupling interfaces 36, 46. At the same time the printing cylinder 18 is secured at the end effector 34 via the securing means 50, 42.

[0102] When connecting to the coupling interface 46 of the printing tool 18, the coupling interface 36 of the printing tool handling unit 28 is moved concentrically to the coupling interface 36 of the printing tool 18.

[0103] In detail, the contact surface 38 of the end effector 34 is brought in close proximity of the contact surface 48 of the printing cylinder 18, while the securing claws 43 are held in the release position by the actuation rod 44.

[0104] Then, the securing claws 43 are actuated via the actuation rod 44 such that the securing claws 43 are moved to the respective securing position (cf. FIG. 6).

[0105] In doing so, the contact surfaces 38, 48 are brought into abutment.

[0106] Thereafter the printing cylinder 18 is removed from the printing machine 12 along its axis of rotation. At the same time the coupling interface 46 provided on the shaft 60 and the coupling interface 70 provided on the output shaft 68 of the drive unit 64 are uncoupled.

[0107] The printing cylinder 18 can now be moved to a storage unit by the printing tool handling unit 28 and a different printing cylinder can be inserted into the printing machine 12.

[0108] In the example shown the printing cylinder 18 is moved to a separation unit 78.

[0109] The separation unit 78 comprises a clamping device 80.

[0110] The printing tool handling unit 28 places the printing cylinder 18 in the clamping device 80 which clamps a sleeve 18a of the printing cylinder 18 (cf. arrows in FIG. 13).

[0111] In this condition the shaft 60 and an adapter 18b of the printing cylinder 18 being interposed between the shaft 60 and the sleeve 18a can be separated from the sleeve 18a by pulling them out of the sleeve 18a along the axis of rotation of the printing cylinder (cf. FIG. 14).

[0112] If the adapter 18b shall also be separated from the shaft 60, the assembly comprising the adapter 18b and the shaft 60 can be moved to a further clamping device 82 in which the adapter 18b will be clamped (cf. arrows in FIG. 15).

[0113] As a consequence thereof, that the shaft 60 can be withdrawn from the adapter 18b by pulling it out along an axis of rotation of the printing cylinder 18 (cf. FIG. 16).

[0114] Thereafter the shaft 60 can be moved to another clamping device 84 and clamped therein (cf. arrows in FIG. 17).

[0115] Now the securing means 42, 50 and the coupling interfaces 36, 46 can be disconnected such that the shaft 60 can be separated from the end effector 34 (cf. FIG. 18).

[0116] As a result of this procedure, the components of the printing cylinder 18, i.e. the sleeve 18a, the adapter 18b and the shaft 60 are stored separately such that they can be automatically recombined if needed.

[0117] The printing tool handling unit 28 is free to handle other printing tools.

[0118] The above procedure is preferably performed in a fully automatic manner.

[0119] It is understood that the above procedure can be applied in an analogous manner for inserting a printing tool into the printing machine 12.