ITFI20130287A1 - "SYSTEM FOR THE REPLACEMENT OF INTERCHANGEABLE SLEEVES IN PRINTING AND SIMILAR MACHINES AND ITS METHOD" - Google Patents

Description

"SYSTEM FOR THE REPLACEMENT OF INTERCHANGEABLE SLEEVES IN PRINTING MACHINES AND SIMILAR, AND RELATIVE METHOD"

DESCRIPTION

TECHNICAL FIELD

The present invention relates to improvements to systems, devices and methods for changing or replacing interchangeable sleeves or shirts in printing machines.

STATE OF THE TECHNIQUE

In some types of printing machines, for example flexographic printing machines with central drum, the web material to be printed, for example a sheet of cellulosic material, plastic or the like, is conveyed around a main roller called drum. One or more printing units are arranged around the main drum, each of which prints with a color, so as to obtain a polychrome print on the final product. The printing units usually comprise an anilox roller that receives the ink from a source, possibly including an inking roller, and transfers the ink to a cliché carried by a cliché roller. The cliché is in contact with the ribbon-like material returned around the central drum to transfer the ink according to a drawing or writing, made on the cliché.

When the design or writing to be printed on the web material has to be changed, one or more cliché rolls must be replaced. EP 0400517 describes a system for replacing cliché rollers by means of a manipulator that engages an end tang of each cliché roller to be replaced in order to extract it from the machine, deposit it in a warehouse and replace it with a different cliché roller taken from the aforementioned warehouse, in which the cliché rollers they are arranged horizontally and rest, with their respective tangs, on support brackets.

In more recent times, to simplify the replacement of the printing design, the monolithic cliché rollers have been replaced by cliché rollers consisting of a plate-holder shaft, on which interchangeable sleeves or liners are invested, each of which includes a cylindrical body hollow, which is hit on the plate-holder shaft and torsionally locked to it. The external surface of the interchangeable sleeve is equipped with a cliché with the respective design. Examples of interchangeable sleeves are described in US2002 / 0129720, EP1594697 and EP1511628. In this way, the replacement affects only the sleeve and not the entire plate holder roller, since the plate holder shaft is kept stably in the printing machine.

The handling of the interchangeable sleeves from the printing machine to the warehouse and vice versa is a complex operation that requires expensive and bulky handling devices and ample room for maneuver.

SUMMARY OF THE INVENTION

The invention relates to a system for replacing interchangeable sleeves which solves in whole or in part at least one of the drawbacks of known systems.

The present invention provides a system for moving and handling the interchangeable sleeves in printing machines or the like, which is more efficient and more compact.

According to one aspect, a system is provided for replacing interchangeable sleeves, in particular interchangeable cliché-holder sleeves in a printing machine, comprising a manipulator with gripping members for gripping and moving the interchangeable sleeves, in which the socket configured to be axially inserted into the interchangeable sleeve and to constrain the interchangeable sleeve to the manipulator. Advantageously, the gripping members can comprise two devices which can be approached and removed from each other to fit into the interchangeable sleeve and constrain the interchangeable sleeve at two points spaced apart along the axial extension of the sleeve itself.

In some embodiments, the gripping members can comprise a first gripping head and a second gripping head, which can be axially inserted into the interchangeable sleeve to be manipulated, and movable with respect to each other to approach and move away from each other along a parallel direction. to the axis of the interchangeable sleeve to be manipulated.

In this way, the gripping heads can engage the interchangeable sleeve or liner initially at one of its ends, and subsequently, by translating the second head inside the interchangeable sleeve, even in an intermediate position approximately corresponding to the center line, or closer to the second end of the sleeve. The sleeve is then initially supported by the first head and by a plate holder shaft; subsequently, the plate-holder shaft is partially extracted to make the second head penetrate into the interchangeable sleeve and, once the final position of the second head inside the interchangeable sleeve has been reached, this can be completely released from the plate-holder shaft and transferred to a warehouse. With reverse operations a new interchangeable sleeve can be taken from the warehouse and inserted into the printing machine.

Advantageously, the manipulator can be carried by a robot, for example by a robot comprising an arm for moving the manipulator. In some embodiments, the movement arm can be an anthropomorphic arm, equipped with a plurality of mutually articulated portions, so as to be able to rotate around one or more axes and perform complex movements. This allows the interchangeable sleeves to be oriented easily and in a small space, bringing them from the horizontal working position to a storage position in the warehouse, in which the interchangeable sleeves are positioned with their own axis approximately vertical.

Arranging the interchangeable sleeves in the magazine with their axis approximately vertical has considerable advantages. For example, with this arrangement the overall dimensions of the warehouse can be reduced. In addition, the interchangeable sleeves can rest on supports or support surfaces of the warehouse through their head surface, avoiding the risk of damage to their cylindrical surface, where the incision is located.

In some embodiments, to simplify the transfer of an interchangeable sleeve from the manipulator to the printing machine, it may advantageously be provided that the manipulator comprises a pusher arranged and controlled to axially push and remove the interchangeable sleeve from the first gripping head and from the second gripping head.

In some embodiments, an actuator can be advantageously provided to move a rod carrying one of the gripping heads with respect to the other. In advantageous embodiments, the other gripping head can be stationary with respect to the manipulator.

The system can comprise a magazine of interchangeable sleeves, equipped with seats in which the interchangeable sleeves are inserted and held preferably with their axis in a substantially vertical position. In some embodiments, several magazines of interchangeable sleeves can be provided. Preferably, the magazine or magazines of interchangeable sleeves can be mobile, by hand or in a motorized manner. For example, it can be provided that the or each magazine is mounted on wheels.

In advantageous embodiments, the magazine can have pins or rods supporting the interchangeable sleeves, arranged approximately vertically, so as to be able to invest a respective interchangeable sleeve on each pin or rod by inserting the pin into the central hole of the interchangeable sleeve.

At least one of said first gripping head and second gripping head can be advantageously expandable. Advantageously, the gripping head intended to engage closer to the end of the interchangeable sleeve is expandable, for example with a hydraulic or pneumatic expansion system, but preferably with a mechanical expansion system. The other gripping head can be non-expandable. Preferably, however, the second gripping head, intended to be inserted more deeply into the axial hole of the interchangeable sleeve, is also expandable, mechanically, hydraulically or - preferably - pneumatically. In this way an easier insertion and an effective locking of the gripping head in the interchangeable sleeve is obtained.

According to a different aspect, the invention relates to a plant comprising a system defined above in combination with a printing machine equipped with a plurality of printing groups, each comprising at least one plate-holder shaft configured and arranged to receive interchangeable sleeves. The printing machine can be a flexographic printing machine. In some embodiments, as illustrated in the annexed drawings, the printing machine can comprise a central drum, around which a continuous web material to be printed is conveyed and around which one or more printing units are arranged. In other configurations, the printing machine can comprise a plurality of drums or back-up rollers, optionally one for each printing unit.

In advantageous embodiments, each printing group comprises a pusher for axially moving the interchangeable sleeve with respect to the plate-holder shaft. For example, a pusher equipped with a gripping jaw can be provided, configured to engage the end of the interchangeable sleeve opposite the end in which the manipulator gripping heads engage.

In some embodiments, each plate-holder shaft intended to support interchangeable sleeves can be provided with an axial movement, i.e. parallel to its own axis of rotation, to extract one end of the plate-holder shaft from the respective support bearing which is located on the side of the printing machine from which the interchangeable sleeves are pulled out or inserted into the machine.

In advantageous embodiments, the support bearing of the axially movable plate holder shaft is equipped with a movement to withdraw with respect to the end of the plate holder shaft and the corresponding end of the interchangeable sleeve. For example, the support bearing can be movable in an orthogonal direction or approximately orthogonal to the axis of the plate holder shaft. In this way it is possible to make the end of the interchangeable sleeve easily accessible to the manipulator. In advantageous embodiments, the or each printing unit can have a pair of actuators, for example electronically controlled electric motors, which move both support bearings of the plate-holder shaft in an approaching and moving away direction with respect to the drum or counter-roller, with which the interchangeable sleeve cooperates. In this way, the interchangeable sleeve and the relative plate-holder shaft can be moved away from the drum or counter-roller to allow the interchangeable sleeve, on which the printing plate is applied or made, to be removed. With a reverse movement, the interchangeable sleeve can be brought back into contact with the material to be printed returned around the drum or counter-roller. Using two independent motors or actuators, it is possible to move the two support bearings together with respect to the drum or counter-roller simultaneously, for the purposes indicated above, or to move only the support bearing on the side or side of the machine from which they are moved. interchangeable sleeves.

Further actuators or motors can be provided to move an anilox roll and / or an ink source to move it away and bring it closer to the relative interchangeable sleeve, so as to allow the movement in the axial direction of the latter to carry out its replacement.

In advantageous embodiments, the plate holder shaft bearing, opposite to the retractable support bearing to make the end of the interchangeable sleeve accessible, can be mounted on an axially movable support, i.e. parallel to the axis of the plate holder shaft, to for example by means of an electric actuator, so as to move the plate-holder shaft. The movable support can be carried by a slide, which is in turn movable in the direction of approach and removal with respect to the drum or counter-roller onto which the web material to be printed is conveyed.

According to a further aspect, the invention relates to a method for replacing interchangeable sleeves in a printing machine, comprising the steps of: gradually removing a first interchangeable sleeve from a plate-holder shaft of a printing unit of the printing machine, by inserting inside the interchangeable sleeve a first gripping head and a second gripping head, movable relative to each other; deposit the first interchangeable sleeve in a warehouse; picking up a second interchangeable sleeve from said magazine by inserting said first gripping head and said second gripping head inside it; insert the second interchangeable sleeve on the plate holder shaft by gradually bringing the first gripping head and the second gripping head closer to each other; release the second interchangeable sleeve on the plate holder shaft by removing the first gripping head and the second gripping head from the second interchangeable sleeve.

Advantageously, the interchangeable sleeves are arranged in the magazine with their axis oriented vertically.

According to a particularly advantageous embodiment, the method can comprise the following steps:

• release a first end of the plate holder shaft from an end support and make one end of said first interchangeable sleeve accessible to a manipulator and possibly support the interchangeable sleeve temporarily through the cantilevered plate holder shaft;

• axially move the first interchangeable sleeve with respect to the plate-holder shaft, creating a space inside the first interchangeable sleeve adjacent to said end of the first interchangeable sleeve;

• inserting the first gripping head and the second gripping head in said space and axially constraining the first gripping head to the first interchangeable sleeve, the two gripping heads being preferably carried by a manipulator;

• gradually remove the interchangeable sleeve from the plate holder shaft through the first gripping head, gradually inserting the second gripping head axially inside the first interchangeable sleeve up to an intermediate position of said first interchangeable sleeve;

• preferably constraining the second gripping head to the first interchangeable sleeve, for example by expanding the second gripping head;

• completely remove the first interchangeable sleeve from the plate holder shaft supporting it through the first gripping head and the second gripping head;

• place the first interchangeable sleeve in the warehouse;

• insert the first gripping head and the second gripping head into a second interchangeable sleeve positioned in the magazine and bind at least the first gripping head to the interchangeable sleeve;

• extracting said second interchangeable sleeve from the magazine;

• insert the second interchangeable sleeve on the plate holder shaft, moving the second gripping head back towards the first gripping head while the plate holder shaft penetrates the first interchangeable sleeve.

According to advantageous embodiments, the method can further comprise the steps of: rotating the axis of the first interchangeable sleeve from a substantially horizontal position to a substantially vertical position to insert the first interchangeable sleeve in the magazine with its axis oriented substantially vertically; and rotate the axis of the second interchangeable sleeve taken from the warehouse from a substantially vertical position to a substantially horizontal position to insert the second interchangeable sleeve on the plate holder shaft.

According to a further aspect, the invention relates to a system for replacing interchangeable sleeves in a printing machine, comprising a manipulator with gripping members configured and controlled to be inserted inside the interchangeable sleeves, in which the manipulator is provided: of a movement of extraction of the interchangeable sleeves from the machine in a direction parallel to the axis of the interchangeable sleeve when it is in the machine, and of rotation of the interchangeable sleeve to position and release in a magazine the interchangeable sleeve extracted from the machine with its own axis in a substantially vertical position; and a movement of withdrawing an interchangeable sleeve in a substantially vertical position from the magazine, of rotation of the interchangeable sleeve to position the interchangeable sleeve with its axis in a horizontal position, and of insertion of the interchangeable sleeve on a plate-holder shaft of the machine.

According to yet another aspect, the invention relates to a method for replacing interchangeable sleeves in a printing machine, comprising the steps of:

• extracting a first interchangeable sleeve from a printing unit, for example by sliding it off a plate-holder shaft;

• rotate the axis of the first interchangeable sleeve in a substantially vertical position;

• release the first interchangeable sleeve in a warehouse;

• taking from the magazine a second interchangeable sleeve housed in said magazine with its axis in a substantially vertical position;

• rotate the axis of the second interchangeable sleeve bringing it to a substantially horizontal position;

• insert the second interchangeable sleeve into the printing unit.

Characteristics and embodiments are described below and further defined in the attached claims, which form an integral part of the present description. The above short description identifies characteristics of the various embodiments of the present invention so that the following detailed description can be better understood and so that the contributions to the art can be better appreciated. There are, of course, other features of the invention which will be described later and which will be set out in the attached claims. With reference to this, before illustrating various embodiments of the invention in detail, it should be understood that the various embodiments of the invention are not limited in their application to the construction details and arrangements of components described in the following description or illustrated in the drawings. The invention can be implemented in other embodiments and implemented and put into practice in various ways. Furthermore, it is to be understood that the phraseology and terminology employed herein are for descriptive purposes only and should not be regarded as limiting.

Those skilled in the art will therefore understand that the concept upon which the disclosure is based can readily be used as a basis for designing other structures, methods and / or other systems for carrying out the various objects of the present invention. It is therefore important that the claims be considered as including those equivalent constructions that do not depart from the spirit and scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood by following the description and the attached drawing, which shows a practical non-limiting embodiment of the invention. More specifically, in the drawing: the

Fig.1 shows a schematic front view of the printing area of an eight-color flexographic machine; there

Fig.2 shows a plan view along the line II-II of Fig.1; Fig.3 shows an enlargement of the detail III of Fig.2; there

Fig.4 illustrates an initial phase of the process of replacing the interchangeable sleeve of one of the printing units of the machine of Fig.1, in a front view; there

Fig.5 shows a plan view along the line V-V of Fig.4; Fig.6 shows an enlargement of the detail VI of Fig.5; there

Fig.7 shows a subsequent step of the replacement process in a plan view similar to Fig.5; there

Fig.8 shows an enlargement of the detail VIII of Fig.7; the

Figures 9 and 10 show successive steps of handling the interchangeable sleeve; there

Fig.11 shows a side view along the line XI-XI of Fig.10; Fig.11A shows an enlargement of the detail indicated by XIA in Fig. 11; there

Fig.12 shows a front view of the robot with the interchangeable sleeve to be replaced in vertical position; there

Fig.12A shows an enlargement of the detail XIIA of Fig.12; Fig.13 shows a plan view along the line XIII-XIII of Fig.12; there

Fig.14 shows a view along the line XIV-XIV of Fig.13; Fig.15 shows, in a view similar to Fig. 14, a subsequent step for inserting the interchangeable sleeve into the magazine; there

Fig.15A shows an enlargement of the cut XVA of Fig.15; Fig.16 shows a plan view along the line XVI-XVI of Fig. 15; there

Fig. 17 shows, in a view similar to the view of Fig. 15, the step of taking an interchangeable sleeve from the magazine; there

Fig.18 shows the subsequent handling phase of the interchangeable sleeve from the magazine; there

Fig.19 shows a plan view along the line XIX-XIX of Fig. 18; there

Fig.20 shows a front view of the printing machine in the step of inserting the new interchangeable sleeve; there

Fig.21 shows a plan view along the line XXI-XXI of Fig. 20; there

Fig. 22 shows a side view along the line XXII-XXII of Fig. 21; there

Fig. 23 shows a plan view, similar to Fig. 21, of the initial insertion phase of the new interchangeable sleeve in the printing machine; there

Fig.24 illustrates, in a view similar to Fig.23, the step of completely inserting the interchangeable sleeve into the printing unit; there

Fig.25 shows an enlargement of the detail of XXV of Fig.4; Fig. 26 shows the step of releasing the interchangeable sleeve into the printing machine in a plan view; there

Fig.27 shows an enlargement of detail XXVII of Fig.26; Fig. 28 illustrates the closing phase of the plate holder shaft after replacing the interchangeable sleeve in a plan view; Fig.29 shows an enlargement of the detail XIX of Fig.28; Fig.30 shows an enlarged front view of a single printing unit in the working position; there

Fig.31 shows a plan view along the line XXXI-XXXI of Fig.30; there

Fig. 32 shows a front view similar to the view of Fig. 30, with the printing unit in the open position, for the extraction of the interchangeable sleeve; and the

Fig. 33 shows a plan view along the line XXXIII-XXXIII of Fig. 32.

DETAILED DESCRIPTION OF FORMS OF IMPLEMENTATION

The following detailed description of exemplary embodiments refers to the accompanying drawings. The same reference numerals in different drawings identify the same or similar elements. Also, the drawings are not necessarily to scale. The detailed description that follows does not limit the invention. Rather, the scope of the invention is defined by the attached claims.

Reference throughout the description to "an embodiment" or "the embodiment" or "some embodiment" means that a particular feature, structure or element described in connection with an embodiment is included in at least one embodiment of realization of the described object. Therefore the phrase "in an embodiment" or "in the embodiment" or "in some embodiment" at various points along the description does not necessarily refer to the same or the same embodiments. Furthermore, the particular features, structures or elements can be combined in any suitable way in one or more embodiments.

Fig.1 schematically shows a view of a side of a flexographic printing machine indicated as a whole by 1. The printing machine 1 comprises a main drum 3 around which the continuous substrate to be printed is sent, for example a sheet of paper or other cellulosic material, a fabric, a non-woven fabric, a plastic film or the like. The drum 3 is associated with printing units indicated from 5A to 5G. In the example shown, eight printing groups are provided, but it must be understood that the number of printing groups may vary depending on the number of colors for which the machine is set up 1.

Each printing unit 5A-5G comprises a cliché roller 6, on the surface of which the cliché bearing the design or writing to be printed on the web material returned around the drum 3 is made or carried. As shown schematically for example in Fig.2 , each cliché roller 6 is actually constituted by a plate-holder shaft 7 and by an interchangeable sleeve 9, on whose external cylindrical surface the actual plate is carried. More constructive details on the single printing unit and on the parts provided to carry out the movement of the various components of the printing unit, in order to replace the interchangeable sleeve, will be described later with reference to Figs. 30 to 33.

The plate-holder shaft 7 is supported at its ends 7A, 7B by respective supports 11A, 11B carried by the sides 12 of the machine (see the enlargement of Fig. 3 and for more details Figs. 30-33, described later on ).

The machine 1 is associated with a system for replacing the interchangeable sleeves 9 of each printing unit 5A-5G. In some embodiments, the sleeve replacement system 9 may comprise a robot 13 placed on the operator side of the printing machine 1. The robot 13 may comprise an arm 15, for example a so-called anthropomorphic arm, i.e. consisting of a plurality of sections articulated to each other in such a way as to perform the movements according to a plurality of axes distributed in space, so that the terminal end of the arm, indicated with 15A, on which a manipulator 21 is mounted, described in greater detail below, can perform the movements necessary to remove the interchangeable sleeves 9 of the 5A-5G printing units, position them in one or more magazines of interchangeable sleeves and replace them with interchangeable sleeves taken from the aforementioned magazines.

The structure of the robot 13 can be a structure known per se and will therefore not be described in greater detail.

The system for replacing the interchangeable sleeves comprises, in addition to the robot 13, at least one magazine, preferably a mobile magazine, of interchangeable sleeves. In the embodiment illustrated in the drawings, the system for replacing the interchangeable sleeves comprises two magazines of interchangeable sleeves, indicated with 17A and 17B. The magazines 17A, 17B can be mounted on mobile trolleys 18A-18B (see Fig. 4). The magazines 17A, 17B can be moved manually by an operator. In other embodiments, an automated movement of the magazines 17A, 17B can be provided, for example on rails suitably positioned with respect to the printing machine 1.

As can be seen in particular in Figs. 11A, 12A and 15A, which show enlargements of the manipulator 21 fixed to the end 15A of the arm 15, in some embodiments said manipulator 21 comprises a first head or gripping head 23, which can be fixedly mounted with respect to a frame 22, articulated at the end 15A of the arm 15. An actuator 25 is fixed to the frame 22 of the manipulator 21, for example a cylinder-piston without rod or other linear actuator. The linear actuator 25 controls the movement according to the double arrow f25 of a slide 27 which carries a rod 29. The rod 29 carries, at its distal end, a second head or gripping head 31, which is therefore movable in a axial direction according to f25 to approach and move away from the first head or gripping head 23.

In some embodiments, the first gripping head 23 can be an expandable head, with an expansion mechanism for example of a mechanical type, for example with an expansion cam, for the purposes that will be clarified below. In some embodiments, the gripping head 31 can also be expandable, with mechanical expansion systems, or, preferably, with pneumatic expansion systems.

The heads or gripping heads 23, 31 are configured to fit into the interchangeable sleeve 9 which must be moved from time to time, in the manner described below, to engage said interchangeable sleeve 9 and transfer it from the printing machine 1 to the warehouse 17A or 17B, or vice versa from the aforementioned warehouse to the machine.

With reference to the sequence of Figs. 1 to 16 the procedure by which the replacement of the interchangeable sleeves 9 is carried out will now be described.

Figures 1, 2 and 3 show the printing machine 1 in operating condition. As noted above, each printing unit 5A-5G has a respective cliché roller 6 formed by a plate-holder shaft 7 and an interchangeable sleeve 9. For simplicity of representation, Fig. 2 shows a single cliché roller 6, whose interchangeable sleeve 9 must be removed from the plate-holder shaft 7 and replaced with another interchangeable sleeve brought from magazine 17B. The latter generally has a plurality of seats for the interchangeable sleeves 9, at least one of which must be empty, as shown with S9, to allow the transfer of the interchangeable sleeve 9 coming from the machine 1 to the magazine 17B.

To remove the interchangeable sleeve 9 of each printing unit 5A-5H, it is first necessary to move the cliché roller 6 away from the surface of the drum 3 and move the ink source, schematically indicated with 8 for each printing unit 5A-5H, away from the surface of the respective plate-holder roller 6. Subsequently, the plate-holder shaft 7 of the plate-holder roller 6 whose interchangeable sleeve 9 must be replaced, is set back with respect to the interchangeable sleeve 9 with a movement parallel to its own axis for the purposes that will become clear in the following. The devices and mechanisms for carrying out these movements will be described in greater detail later with reference to Figs. 30 to 33.

By moving back the plate-holder shaft 7 with respect to the sleeve 9, the end 7A of the plate-holder shaft 7 is removed from the respective support 11A, which can be translated along the side 12 (arrow f11 in Fig. 6) making it accessible to the manipulator 21 the terminal end of the interchangeable sleeve 9. In Fig. 6 with f7 the retraction movement of the plate-holder shaft 7 is shown.

Figs. 7 and 8 show the subsequent phase of the replacement cycle of the interchangeable sleeve 9, which provides for the axial movement according to arrow f9 (Fig. 8) of the interchangeable sleeve, so as to create a free space 9A inside the interchangeable sleeve 9, between the terminal end 9X of the sleeve 9 and the end 7A of the plate-holder shaft 7 (see Fig. 8). The pair of gripping heads 31 and 23 carried by the manipulator 21 of the robot 13 are inserted into this free space 9A. The axial movement of the interchangeable sleeve 9 is obtained with a mechanism described later with reference to Figs. 30 to 33.

The gripping head 23 can be expanded to be axially constrained to the interchangeable sleeve 9, while the second gripping head 31 preferably remains in an unexpanded position, in order to be able to slide inside the axial cavity of the interchangeable sleeve 9 in the subsequent handling phase, illustrated in Fig. 9.

As can be understood from the sequence of Figs. 7 and 9, once the first gripping head 23 has been linked to the interchangeable sleeve 9, by means of movements of its own arm 15 the robot 13 can start extracting the interchangeable sleeve 9 from the unit printing 5H of the printing machine 1, as shown in Fig. 9 (arrow f9).

By gradually withdrawing the interchangeable sleeve 9 from the plate holder shaft 7, the internal space of the sleeve 9 is freed, so that the second expandable head 31 can be inserted towards the inside of the interchangeable sleeve 9 by means of the linear actuator 25. The length of the the rod 29 is preferably such that the second gripping head 31 can penetrate the interchangeable sleeve 9 up to approximately a central position or even beyond the center line of the interchangeable sleeve 9. Once this position has been reached, if necessary, the gripping head 31 can be expanded to grip the internal surface of the axial hole of the interchangeable sleeve 9. In the step illustrated in Fig. 9 the interchangeable sleeve 9 is still supported at the opposite end with respect to the one attached to the first gripping head 23, by the plate-holder shaft 7. The latter is in turn supported cantilevered by the support opposite to the side 12 on the operator side.

Once the second expandable head 31 has been completely inserted inside the interchangeable sleeve 9, the robot 13 can completely remove the interchangeable sleeve 9 from the plate-holder shaft 7 and from the printing machine 1, as shown in Fig. 10 . In this arrangement, the interchangeable sleeve 9, still in a horizontal position, is supported by the two gripping heads 23 and is held cantilevered by the manipulator 21 carried by the end 15A of the arm 15 of the robot 13.

As noted above, the magazines 17A and 17B are configured to support the interchangeable sleeves 9 in a vertical position, ie with their axis oriented approximately vertically. Therefore, the interchangeable sleeve 9 just extracted from the printing machine 1 must be rotated by the robot 13 to assume the position illustrated in Figs. 12, 13 and 14, with its axis A-A oriented substantially in the vertical direction. This movement is imparted by the anthropomorphic arm 15 of the robot 13, while the interchangeable sleeve 9 is firmly held by the gripping heads 23 and 31.

A further movement the arm 15 of the robot 13 brings the interchangeable sleeve 9 into alignment with a stem 33 positioned in the free seat S9 of the magazine 17B and lowers (arrow f9 in Fig. 15) the interchangeable sleeve 9 inserting it on the stem 33. In this step the second gripping head 31 can be made to move back on command of the linear actuator 25, to free the internal space of the interchangeable sleeve 9 allowing the rod 33 to penetrate.

Once the interchangeable sleeve 9 has been placed with the lower end on the magazine 17B, the gripping heads 23, 31 can be extracted from the interchangeable sleeve 9 and the manipulator 21 can be raised and positioned in axial alignment with a second interchangeable sleeve 9.2, brought from warehouse 17B or, alternatively, from warehouse 17A. This second interchangeable sleeve 9.2 will be taken from the magazine by means of the robot 13 and inserted into the machine 1 with a substantially inverse procedure with respect to that described up to now.

In Fig.17 the manipulator 21 has been brought by the arm 15 of the robot 13 into axial alignment with a new interchangeable sleeve 9.2, in this example carried by the magazine 17B. The lowering of the manipulator 21 brings the gripping heads 23 and 31 inside the interchangeable sleeve 9.2. The gripping head 23 is expanded and axially constrained to the interchangeable sleeve 9.2, so that the latter can be raised, while the second gripping head 31 is gradually inserted inside the interchangeable sleeve 9.2 up to the maximum insertion position determined by the length. of the rod 29. This movement of penetration of the rod 29 and of the gripping head 31 inside the interchangeable sleeve 9.2 can be accompanied by the lifting movement of the interchangeable sleeve 9.2 held by the gripping head 23, so that the stem 33 on which this sleeve is invested is gradually withdrawn leaving the space for the insertion of the second gripping head 31.

The second interchangeable sleeve 9.2 is subsequently raised and laterally translated (Fig. 18 and 19) and rotated by 90 ° to bring its axis A-A from the substantially vertical position in which it was in the magazine 17B, to the substantially horizontal position ready for insertion. in the printing machine 1, as illustrated in Figs. 20 to 22.

Figs. 23 and 24 show the insertion movement (arrow f9 in Fig. 23) of the interchangeable sleeve 9.2 into the printing machine 1 and onto the plate-holder shaft 7. The movement is accompanied (Fig. 24) by a gradual retraction of the second head 31 to leave the necessary space for the insertion of the plate-holder shaft 7. In Fig. 24, the gripping heads 31 and 23 are close together and positioned near the end of the operator side of the interchangeable sleeve 9.2, as shown visible in particular also in the enlargement of Fig. 25.

The subsequent operating phase involves the complete removal of the rod 29 and of the gripping heads 23, 31 from the interchangeable sleeve 9.2 to completely free the interchangeable sleeve 9.2 from the gripping heads 23 and 31 and allow the plate-holder shaft 7 to be inserted into the interchangeable sleeve 9.2 and protrude with its end 7A from the sleeve itself. In this phase, the interchangeable sleeve is supported cantilevered by the plate holder shaft 7. The movement of complete extraction of the interchangeable sleeve 9 from the gripping heads 23, 31 can be imparted by a pair of pushers 35 carried by the manipulator 21, as shown in Fig. .27.

F35 indicates the movement of the pair of pushers 35 which completely introduce the interchangeable sleeve 9.2 inside the printing machine 1.

Simultaneously or subsequently to the movement of complete insertion of the interchangeable sleeve 9.2 into the printing machine 1, the plate-holder shaft 7 can be moved according to the arrow f7 in the axial direction (Fig. 27) to approach the side 12 of the printing machine 1 .

The manipulator 21 can be moved away from the side 12 of the printing machine 1 leaving free the space to bring the support 11A back into axial alignment with the plate-holder shaft 7. A further movement according to the arrow f7 (Fig. 29) shows the plate-holder shaft 7 in the working position with its end 7A engaged in the support 11A.

The printing machine 1 is now again in a position to resume printing, after moving the cliché roller 6 to the drum 3 and the ink source 8 to the cliché roller 6.

The cycle described up to now can be repeated for all the interchangeable sleeves with which the printing machine 1 is equipped.

Hereinafter, with reference to Figs. 30-33, a possible configuration of the members which carry out the reciprocal movement between the plate roller 9, drum 3, plate-holder shaft 7, ink source 8 and support 11A will be described.

Figures 30 to 33 show a generic printing unit, indicated by 5, in a front view and in a plan view and in two configurations. All the printing units 5A-5G can be substantially equipped with the same components described below with reference to Figs. 30-33.

More specifically, in Figs. 30 and 31 the generic printing unit 5 is in the printing position, with the cliché roller 6 resting on the central drum 3 and the ink source 8 adhering to the cliché roller 6, to distribute on the external cylindrical surface of it the ink for printing. The plate holder shaft 7 is supported at both ends 7A, 7B by the respective bearings 11A, 11B. Fig. 31 also shows a motor 41 which rotates the cliché roller 6 and a motor 43 which rotates an anilox roller which distributes the ink on the cliché roller 6. Each printing unit 6 can be equipped with its own independent motors 41 and 43 for the respective cliché rolls 6 and anilox rolls.

The support 11B of the plate-holder shaft 7 is contained in a housing 45 which can be integral with a base 47, on which the motor 41 is also mounted. The base 47 can be equipped with a movement according to the arrow f7, to move the plate-holder shaft 7 parallel to itself.

The base 47 is carried by a slide 49 equipped with a movement according to the double arrow f49, in a direction orthogonal to the axis A7-A7 of the plate holder shaft 7. The slide 47 can be mobile on guides fixed to the side of the printing machine 1 , not shown for simplicity of representation.

The movement according to f7 of the base 47 can be controlled by an electric motor or other actuator, not visible, placed for example under the base and which can rotate a threaded bar with which a nut screw integral with the base 47 is engaged, or otherwise way.

The movement according to f49 of the slide 49 can be imparted by an electric motor, or other suitable actuator, indicated with 51, for example by means of a threaded bar 53 which can mesh with a nut screw integral with the slide 49.

On the opposite side with respect to the motor 41, the plate-holder shaft 7 is supported by the support 11A, which can be mounted on a slide 55, movable according to the double arrow f11 along guides, not shown, integral with the side of the printing machine 1 on the operator side, opposite the side that carries the slide 49. The movement according to the double arrow f11 can be controlled by a motor 57, for example by means of a threaded bar 59, meshing with a nut screw, not shown, carried by the slide 55.

The ink source 8, which includes for example the anilox roller that distributes the ink to the cliché roller 6, can be supported by two slides 8A, 8B, mounted on the two opposite sides of the printing machine 1. Each slide 8A, 8B can be moved according to the double arrow f8 by means of two motors 61A, 61B which rotate respective threaded bars 63A, 63B, which can engage with nut screws not shown, integral with the slides 8A, 8B.

The members described up to now with reference to Figs. 30-33 perform the reciprocal approaching and distancing movement between the cliché roller 6, ink source 8 and drum 3, as well as the movement of the support 11A, in order to perform the replacement of the interchangeable sleeve 9. As previously mentioned, in fact, to perform to replace the interchangeable sleeve 9 it is necessary to move the cliché roller 9 away from the drum 3 and from the anilox roller of the ink source 8, and to bring the support 11A out of alignment with respect to the cliché-holder shaft 7. For this purpose, a synchronized movement of the motors 51 and 57 and motors 61A, 61B it is possible to move away the cliché roller 6 from the drum 3 and the ink source 8 from the cliché roller 6. Subsequently, it is possible to axially move the cliché holder shaft 7 (arrow f7) to free the end 7A from the support 11A and therefore, with the movement of the motor 57 alone, it is possible to move the support 11A off-axis with respect to the cliché roller 6, to access the interchangeable sleeve 9 as described above.

The axial movement of the interchangeable sleeve 9 (Fig. 8, arrow f9) can be obtained by means of a linear actuator 65 carried by the slide 49. The linear actuator 65, for example a cylinder-piston actuator or a linear electric motor, controls the movement for extracting and retracting a rod 67, at the distal end of which a thrust member of the interchangeable sleeve 9 is fixed. This thrust member may comprise a gripping jaw 69, the opening and closing of which can be controlled by an electric motor or another actuator 71 brought to the distal end of the rod 67. The movement according to f9 of the interchangeable sleeve 9 is controlled by extracting the rod 67 with the jaws 69, as can be understood by comparing Figs.

31 and 33.

While the disclosed embodiments of the object illustrated herein have been shown in the drawings and fully described above with details and details in relation to several exemplary embodiments, those skilled in the art will understand that many modifications, changes and omissions are possible. without materially departing from the innovative teachings, from the principles and concepts set out above, and from the advantages of the object defined in the attached claims. Therefore, the actual scope of the innovations described must be determined only on the basis of the broadest interpretation of the attached claims, so as to include all modifications, changes and omissions. Furthermore, the order or sequence of any method or process step can be varied or rearranged according to alternative embodiments.

Claims (22)

"SYSTEM FOR THE REPLACEMENT OF INTERCHANGEABLE SLEEVES IN PRINTING MACHINES AND SIMILAR, AND RELATIVE METHOD" Claims 1. A system for replacing interchangeable sleeves, in particular interchangeable cliché-holder sleeves in a printing machine, comprising a manipulator with gripping members for gripping and handling the interchangeable sleeves, in which the gripping members are configured for be inserted axially into the interchangeable sleeve and constrain the interchangeable sleeve to the manipulator. 2. System according to claim 1, in which the gripping members comprise two gripping members which can be approached and removed from each other to fit into the interchangeable sleeve and constrain the interchangeable sleeve at two points spaced along the axial extension of the sleeve itself. 3. system as per claim 1 or 2, in which said gripping members comprise a first gripping head and a second gripping head, which can be axially inserted into the interchangeable sleeve to be manipulated, and movable with respect to each other in order to approach and move away reciprocally along a direction parallel to the axis of the interchangeable sleeve to be manipulated. 4. System according to claim 1, 2 or 3, in which the manipulator is carried by a robot, preferably comprising an arm for moving the manipulator, said arm preferably being an anthropomorphic arm. 5. System according to one or more of the preceding claims, in which said manipulator is movable according to a number of degrees of freedom such as to be able to transfer the interchangeable sleeve from a position in which the interchangeable sleeve is with its axis in a substantially horizontal position , to a position in which the interchangeable sleeve is with its axis in a substantially vertical position. 6. System according to one or more of the preceding claims, wherein said manipulator comprises a pusher arranged and controlled to axially push and remove the interchangeable sleeve from the gripping members of the manipulator. 7. System according to one or more of the preceding claims, in which said manipulator comprises an actuator for moving a rod carrying one of said gripping members with respect to another of said gripping members, which is preferably stationary with respect to the manipulator. 8. System according to one or more of the preceding claims, comprising at least one magazine of interchangeable sleeves, equipped with seats in which said interchangeable sleeves are inserted and held with their axis in a substantially vertical position. 9. System according to one or more of the preceding claims, in which at least one of said gripping members is expandable. 10. A plant comprising a system according to one or more of the preceding claims and a printing machine equipped with a plurality of printing units, each comprising at least one plate-holder shaft configured and arranged to receive interchangeable sleeves. 11. Plant according to claim 10, in which in each printing unit there is a reciprocal movement in the axial direction between the interchangeable sleeve and the plate-holder shaft. 12. Plant as claimed in claim 11, in which each printing unit is associated with a pusher to axially move the interchangeable sleeve with respect to the plate-holder shaft. 13. Plant as per claim 11 or 12, in which the plate holder shaft is equipped with a movement parallel to its axis with respect to supports of the plate holder shaft. 14. Plant as per claim 10, 11 or 12, in which the plate-holder shaft of each printing group is supported at least at one end by an openable or removable support. 15. A method for replacing interchangeable sleeves in a printing machine, comprising the steps of: gradually removing a first interchangeable sleeve from a plate-holder shaft of a printing unit of the printing machine, inserting inside the first interchangeable sleeve gripping members adapted to engage said first interchangeable sleeve; deposit the first interchangeable sleeve in a warehouse; picking up a second interchangeable sleeve from said magazine by inserting said gripping members inside it; insert the second interchangeable sleeve on the plate holder shaft by gradually removing the gripping elements from inside the second interchangeable sleeve; release the second interchangeable sleeve on the plate holder shaft by removing. 16. Method as per claim 15, comprising the steps of inserting in said first interchangeable sleeve at least one pair of gripping members and spacing said gripping members with respect to each other, to engage the second interchangeable sleeve in proximity to one of its extremity and an intermediate position along its axial development; and to insert in said second interchangeable sleeve said pair of gripping members and spacing the gripping members with respect to each other to engage the second interchangeable sleeve near one of its ends and an intermediate position along its axial development. 17. Method as per claim 15 or 16, in which said interchangeable members comprise gripping heads, and in which preferably one and even more preferably both gripping heads are expandable to engage the interchangeable sleeves inside an axial hole. 18. Method according to claim 15 or 16 or 17, in which the interchangeable sleeves are arranged in the magazine with their axis oriented vertically. 19. Method according to one or more of claims 15 to 18, comprising the following steps: - release a first end of the plate-holder shaft from an end support and make one end of said first interchangeable sleeve accessible to a manipulator; - axially move the first interchangeable sleeve with respect to the plate holder shaft, creating a space inside the first interchangeable sleeve adjacent to said end of the first interchangeable sleeve; - inserting a first gripping member and a second gripping member in said space and axially constraining the first gripping member to the first interchangeable sleeve; - gradually remove the interchangeable sleeve from the plate holder shaft through the first gripping member, gradually inserting the second gripping member axially inside the first interchangeable sleeve up to an intermediate position of said first interchangeable sleeve; - completely remove the first interchangeable sleeve from the plate holder shaft supporting it through the first gripping member and the second gripping member; - placing the first interchangeable sleeve in the magazine and removing the first gripping member and the second gripping member from the first interchangeable sleeve; - inserting the first gripping member and the second gripping member in a second interchangeable sleeve positioned in the magazine and binding at least the first gripping member to the interchangeable sleeve; - extracting said second interchangeable sleeve from the magazine; - insert the second interchangeable sleeve on the plate holder shaft, moving the second gripping member back towards the first gripping member while the plate holder shaft penetrates the first interchangeable sleeve. 20. Method as per claim 19, further comprising the steps of: rotating the axis of the first interchangeable sleeve from a substantially horizontal position to a substantially vertical position to insert the first interchangeable sleeve in the magazine with its axis oriented substantially vertically; and rotate the axis of the second interchangeable sleeve taken from the warehouse from a substantially vertical position to a substantially horizontal position to insert the second interchangeable sleeve on the plate holder shaft. 21. A system for replacing interchangeable sleeves in a printing machine, comprising a manipulator with gripping elements configured and controlled to be inserted inside the interchangeable sleeves, in which the manipulator is provided: - of a movement of extraction of the interchangeable sleeves from the machine in a direction parallel to the axis of the interchangeable sleeve, and of rotation of the interchangeable sleeve to position and release in a warehouse the interchangeable sleeve extracted from the machine with its axis in a substantially vertical position; - and a movement of withdrawing an interchangeable sleeve in a substantially vertical position from the magazine, of rotation of the interchangeable sleeve to position the interchangeable sleeve with its axis in a horizontal position, and of insertion of the interchangeable sleeve on a plate-holder shaft of the machine . 22. A method of replacing interchangeable sleeves in a printing press, comprising the steps of: - extracting a first interchangeable sleeve from a printing unit; - rotate the axis of the first interchangeable sleeve in a substantially vertical position; - release the first interchangeable sleeve in a warehouse; - taking from the magazine a second interchangeable sleeve housed in said magazine with its axis in a substantially vertical position; - rotate the axis of the second interchangeable sleeve bringing it to a substantially horizontal position; - insert the second interchangeable sleeve into the printing unit.