Device for printing on hollow bodies
09796173 · 2017-10-24
Assignee
Inventors
- Stephan Behnke (Berlin, DE)
- Wolfgang REDER (Veitshöchheim, DE)
- Ewald Röthlein (Retzstadt, DE)
- Karl SCHÄFER (Kürnach, DE)
- Wolfgang Zink (Theres, DE)
Cpc classification
B41F31/06
PERFORMING OPERATIONS; TRANSPORTING
B41F31/00
PERFORMING OPERATIONS; TRANSPORTING
B41F31/04
PERFORMING OPERATIONS; TRANSPORTING
B41P2235/21
PERFORMING OPERATIONS; TRANSPORTING
B41F31/002
PERFORMING OPERATIONS; TRANSPORTING
B41F17/18
PERFORMING OPERATIONS; TRANSPORTING
B41F31/027
PERFORMING OPERATIONS; TRANSPORTING
B41F31/02
PERFORMING OPERATIONS; TRANSPORTING
B41F17/28
PERFORMING OPERATIONS; TRANSPORTING
B41F27/1206
PERFORMING OPERATIONS; TRANSPORTING
B41F17/002
PERFORMING OPERATIONS; TRANSPORTING
International classification
B41F31/02
PERFORMING OPERATIONS; TRANSPORTING
B41F31/00
PERFORMING OPERATIONS; TRANSPORTING
B41F31/06
PERFORMING OPERATIONS; TRANSPORTING
B41F35/00
PERFORMING OPERATIONS; TRANSPORTING
B41F17/28
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A device for printing on hollow bodies has a plurality of printing units each having a printing cylinder. At least one of the printing units has an inking unit having a chambered doctor blade that provides printing ink. The chambered doctor blade system has at least one ink pan and a doctor blade holder in a single assembly. The single assembly of the chambered doctor blade system is retained in the inking unit only on one side. The assembly of the chambered doctor blade system forms a cantilever arm on a side frame of the inking unit. The assembly of the chambered doctor blade system can be moved axially parallel to the anilox roller and can be removed from the inking unit by that movement.
Claims
1. A device for printing on hollow bodies, comprising: a plurality of printing units, each having a printing forme cylinder and wherein at least one of these printing units has an inking unit including an anilox roller, and has a chamber doctor blade system which supplies ink; at least one ink trough and one doctor blade bar in a single structural unit in the chamber doctor blade system, wherein the single structural unit is held on only one side in the inking unit, wherein the single structural unit forms a cantilever arm on a side frame of the inking unit, and wherein the single structural unit is movable axially parallel to the anilox roller and can be removed from the inking unit by this movement; a plate changer on the at least one of the printing units and assigned to the printing forme cylinder of the at least one of the printing units, wherein a printing forme which is intended for the printing forme cylinder one of is and can be supplied to the plate changer from a side of the at least one of the printing units and which plate changer lies diametrically opposite the one side that holds the single structural unit of the chamber doctor blade system.
2. The device according to claim 1, characterized in that the anilox roller receives ink from the chamber doctor blade system and wherein the one doctor blade bar of the chamber doctor blade system one of is and can be placed axially parallel onto the anilox roller.
3. The device according to claim 2, characterized in that the anilox roller has a temperature control device for controlling a temperature of a lateral surface of the anilox roller.
4. The device according to claim 1, characterized in that an ink forme roller is provided, which ink forme roller one of is and can be thrown onto the printing forme cylinder of the printing unit.
5. The device according to claim 4, characterized in that in an area downstream of the chamber doctor blade system, in a direction of rotation of the anilox roller, and between the chamber doctor blade system and the ink forme roller, a rider roller one of is and can be thrown onto the anilox roller.
6. The device according to claim 4, characterized in that the inking unit has a two-roller roller train, consisting of the ink forme roller and the anilox roller, for the transport of ink from the chamber doctor blade system to the printing forme cylinder.
7. The device according to claim 4, characterized in that the ink forme roller is rotationally driven by the anilox roller by of friction.
8. The device according to claim 4, characterized in that an outer diameter of the anilox roller is greater than an outer diameter of the ink forme roller.
9. The device according to claim 1, characterized in that the chamber doctor blade system has in the single structural unit a pump for conveying ink.
10. The device according to claim 1, characterized in that a mount of the printing forme cylinder is embodied as a cantilevered mount, and wherein the printing forme cylinder is mounted at an end face on a journal.
11. The device according to claim 1, characterized in that the plate changer has a bearing surface for a printing forme to be changed, wherein the bearing surface has two different operating positions, wherein in a first operating position the bearing surface is located laterally next to the printing unit on the printing forme cylinder, and wherein in a second operating position the bearing surface is located in front of, and along the printing forme cylinder.
12. The device according to claim 11, characterized in that the bearing surface of the plate changer is movable linearly along a rotational axis of the printing forme cylinder.
13. The device according to claim 1, characterized in that the printing forme which is intended for the printing forme cylinder can be automatically replaced by use of the plate changer.
14. The device according to claim 1, characterized in that the hollow body is printed in one of a letterpress process, a screen printing process and an offset printing process.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) An exemplary embodiment of the invention is illustrated in the set of drawings and will be described in greater detail in the following. Advantages that are achievable with the invention will be discussed in connection with the exemplary embodiment.
(2) The drawings show:
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DESCRIPTION OF THE PREFERRED EMBODIMENT
(9) In a preferred embodiment, a print motif, i.e. at least one print image, for example multicolored, is printed onto the lateral surface, in particular, of a hollow body in a letterpress printing process. Alternative printing processes include, for example, a screen printing process or an offset printing process or a digital printing process in which no printing formes are used. In the following, the invention will be described by way of example in connection with a letterpress printing process. To implement the letterpress printing process, a printing plate is arranged as a printing forme on the lateral surface of a printing forme cylinder, in particular a plate cylinder. The printing plate, which is ready for use in the printing process, is a printing forme that has a print relief, this print relief presenting a mirror image of the print image intended for the printing process, and in an error-free print operation only the print relief is involved in the transfer of ink that has been supplied by the inking unit to the plate cylinder onto the printing blanket. The printing forme or the printing plate has a plate-shaped, preferably flexible carrier of finite length, for example, made from a steel sheet, with a flexible printing body in particular being arranged on this carrier. At least the opposite ends of the carrier in the circumferential direction of the plate cylinder may be pre-curved, for example corresponding to the curvature of the lateral surface of the plate cylinder, or may also be bent to enable easier mounting of the printing forme, in this case particularly the printing plate, on the plate cylinder. The carrier of the printing forme or the printing plate has a thickness ranging from 0.2 mm to 0.3 mm, for example. The total thickness of the printing plate including its carrier ranges from 0.7 mm to 1.0 mm, for example, and is preferably about 0.8 mm. The printing body is made of plastic, for example. To produce the printing plate which is ready for use in the printing machine, the printing body is exposed, for example, with a negative film that mirrors the print image, and unexposed areas are then removed from the printing body, e.g. by washing or by means of a laser.
(10) A device for printing on or decorating hollow bodies, each of which has in particular a preferably cylindrical lateral surface, preferably has a plurality of printing units, for example eight or ten or even morealso called printing stations, wherein at least one of these printing units, and in the preferred embodiment each of these printing units, has a rotatable printing forme cylinder, more particularly a printing forme cylinder embodied as a plate cylinder. The printing units or printing stations and optionally also the printing forme cylinders in this device are each mounted in a frame and can be used in the same printing process to produce a print motif in multiple colors on the same hollow body, the number of colors corresponding to the number of printing units or printing forme cylinders involved. Each printing forme cylinder or plate cylinder is preferably mounted as a cantilevered component, in which the printing forme cylinder or plate cylinder in question is mounted at one of its end faces, for example on a preferably conical journal. On the lateral surface of each plate cylinder, typically only a single printing plate is arranged, with the carrier of the printing plate fully or at least largely spanning the circumference of the plate cylinder in question, in particular more than 80% thereof. The length of the printing body of the printing plate in the circumferential direction of the plate cylinder in question is preferably shorter than the circumference of the plate cylinder in question. The printing forme or the printing plate is or at least can be arranged particularly magnetically by means of its carrier on the lateral surface of one each of the plate cylinders, that is to say, the printing forme or the printing plate preferably is or will be held in place there magnetically, i.e. by means of a magnetic holding force. In an alternative or supplemental variant of the device for printing on or decorating hollow bodies, each of which has a preferably cylindrical lateral surface, at least one of the printing units, or each of a plurality of these printing units, is embodied as a printing unit that prints in a digital printing process without the use of printing formes, with such a printing unit particularly having at least one inkjet print head or a laser.
(11) The especially simultaneous transfer of a plurality of inks in particular to the lateral surface of the hollow body in question requires proper register to be maintained during ink transfer in order to achieve good print quality in the printing process. To ensure a true-to-register arrangement of the printing forme or the printing plate on the lateral surface of the respective printing forme cylinder or plate cylinder, in the preferred embodiment a plurality of register pins, e.g. the position of each of which is adjustable, is preferably provided on the lateral surface of the printing forme cylinder or plate cylinder in question, which pins engage in corresponding recesses formed on the printing forme or on the printing plate, thereby giving the printing forme or printing plate a defined position in its arrangement on the lateral surface of the printing forme cylinder or plate cylinder in question. In a preferred embodiment, each printing forme cylinder or plate cylinder has a diameter of between 100 mm and 150 mm, more particularly between 120 mm and 130 mm, and the axial length of each printing forme cylinder or plate cylinder is between 200 mm and 250 mm, for example, more particularly between 200 mm and 220 mm. The printing plate to be arranged on the lateral surface of the plate cylinder in question has a width in the axial direction of the plate cylinder in question that ranges from 150 mm to 200 mm, and is preferably about 175 mm.
(12) Each printing forme cylinder used in the printing process and embodied, for example, as a plate cylinder transfers a specific ink with its printing forme or with its printing plate onto a printing blanket. The inks used are typically premixed inks, particularly specially customized inks, which are specifically matched in terms of their respective printability to the material of the hollow body to be printed on, depending on whether the surface to be printed on is made of aluminum, tinplate or plastic, for example. In a preferred embodiment of a device for printing on or decorating hollow bodies, each of which has, for example, a cylindrical lateral surface, a device for transferring ink from the printing forme or the printing plate to the lateral surface of the hollow body in question is provided. This device for transferring ink is embodied, e.g. as a segmented wheel that rotates about a preferably horizontal rotational axis, wherein a plurality of printing blankets preferably are or at least can be arranged one in front of the other on the periphery of this segmented wheel, i.e. along its circumference. As an alternative to the segmented wheel, and depending on the printing process that is used, the device for transferring ink may also be embodied as a decorating drum or as a printing blanket cylinder or as a transfer cylinder, each of which is rotatable about a respective axis of rotation, at least during printing. The printing blankets are arranged on the periphery of the segmented wheel, for example, by attaching each of the printing blankets to the periphery of the segmented wheel, for example, by an adhesive connection, preferably by gluing. Each of the preferably multiple printing forme cylinders or plate cylinders is or at least can be thrown radially onto the printing blankets that are arranged on the periphery of the respective segmented wheel. In a particularly preferred embodiment of a device for printing on or decorating hollow bodies, each of which has, for example, a cylindrical lateral surface, a greater number of printing blankets are provided one in front of the other along the periphery of the segmented wheel than the number of printing forme cylinders or plate cylinders which are or at least can be thrown onto the segmented wheel. The device for transferring ink, preferably in the form of a carousel, more particularly the segmented wheel, has a diameter, for example, of 1500 mm to 1600 mm, preferably approximately 1520 mm to 1525 mm, and when eight printing forme cylinders or plate cylinders are assigned to said device, for example, it has twelve printing blankets, for example, arranged one in front of the other around its periphery. The surface of each of the printing plates is preferably embodied as having a greater hardness than the hardness of the respective surface of the printing blankets. The surface of the printing blankets is preferably flat, i.e. without profiling. In an operating mode in which the printing forme cylinders or plate cylinders involved in the printing process are each thrown radially onto the printing blankets of the rotationally driven segmented wheel, the respective printing formes of each printing forme cylinder or the respective printing plates of each plate cylinder roll along the printing blankets that are moved with the segmented wheel, wherein each of the printing plates presses at least its print relief 0.2 mm to 0.25 mm deep, for example, into the respective printing blanket, thereby producing a flattened area, i.e. a roller strip, extending in the axial direction of the segmented wheel, in the printing blanket in question. The intensity of flattening can be or is adjusted, for example, prior to or at the start of a printing process, for example, by means of remote control, by adjusting a contact force exerted by the relevant printing forme cylinder or plate cylinder on the printing blanket of the segmented wheel in question.
(13) Each of the hollow bodies to be printed on here by way of example, for example each of the two-part cans to be printed on, is moved, for example, by means of a transport device that preferably transports the hollow bodies to be printed on along at least a portion of a circular path, that is, a circular arc, around a rotational axis, preferably by means of a feed wheel, in particular by means of a mandrel wheel, in a continuous movement or with adjusted speed, up to at least one of the printing units belonging to the device for printing on hollow bodies, each of which has a lateral surface, and is thereby transported into a printing area of at least one of these printing units. For example, each of the hollow bodies to be printed on is moved by means of the transport device, embodied, for example, as a feed wheel, up to at least one of the printing blankets arranged, for example, on the segmented wheel, or each of the hollow bodies to be printed on is transported directly and immediately, i.e. without assistance of a device for transferring ink, embodied for example as a segmented wheel, into the respective printing area of at last one of these printing units, which is the case when the printing unit in question prints in a direct printing method, for example in an inkjet printing method.
(14) The feed wheel or mandrel wheel, which, like the segmented wheel, for example, rotates about a preferably horizontal axis, has a plurality of holders, e.g. 24 or 36, each in the form of a clamping mandrel or a spindle that projects outward from a face of the mandrel wheel, for example, with these holders being arranged concentrically to the circumferential line of the feed wheel or mandrel wheel and preferably in an equidistant distribution, wherein each holder holds or at least can hold one of the hollow bodies to be printed on. A transport device embodied as a mandrel wheel is also sometimes referred to as a turntable with spindles. A mandrel wheel is described, for example, in EP 1 165 318 A1. A description of suitable holders, spindles or clamping mandrels may be found, for example, in WO 2011/156052 A1. In the following, each clamping mandrel will be referred to simply as a mandrel. The longitudinal axis of each mandrel is aligned parallel to the rotational axis of the mandrel wheel. In the case of hollow bodies to be printed on, each of which is formed, for example, as a two-part can, each of these hollow bodies is moved, for example by means of a conveyor device, for example a belt conveyor, up to the transport device embodied, for example, as a mandrel wheel, where it is pulled, at a transfer station, onto one of the mandrels of the mandrel wheel by suction, for example by means of a vacuum, and is then held by the mandrel in question, while the transport device embodied as a mandrel wheel transports the respective hollow body to be printed on, for example, to the segmented wheel which is loaded with at least one printing blanket, and thus in the direction of at least one of the printing units, or in an alternative embodiment that has no segmented wheel, for example, directly to at least one of the printing units. Typically, a large number of hollow bodies to be printed on are fed in rapid succession by the conveyor device to the mandrel wheel. A conveyor device of this type is described, for example, in EP 1 132 207 A1.
(15) A gap measuring 0.2 mm in width, for example, is preferably formed between an inner wall of the respective hollow body to be printed on and the surface of the respective mandrel of the mandrel wheel, and therefore the hollow body to be printed on is not held on the mandrel in question by means of a press fit. Each mandrel can be rotated by means of a motor, for example, about its respective longitudinal axis and is particularly adjustable to a specific circumferential speed, so that in addition to being rotated by the mandrel wheel, each hollow body to be printed on that is held by a mandrel can be rotated by rotation that is or at least can be carried out separately by the mandrel. The hollow body to be printed on is preferably pulled onto one of the mandrels of the mandrel wheel during a phase when the mandrel in question is stationary; during said stationary phase, the mandrel in question executes no rotating movement about its own longitudinal axis. The occupancy of each mandrel by a hollow body to be printed on is preferably verified, for example in a contactless manner by means of a sensor. If a mandrel is not occupied by a hollow body to be printed on, the mandrel wheel is moved, for example, in such a way as to reliably prevent any contact of the unoccupied mandrel with a printing blanket of the segmented wheel.
(16) Two-part cans to be printed on are deep-drawn from a circular blank, for example, in a processing station upstream of the mandrel wheel, before being fed to the mandrel wheel. In a further processing station, the edge of each two-part can is trimmed at its open end face. In additional processing stations each two-part can is washed, for example, in particular its inside is washed out. The hollow bodies, each of which is embodied, for example, as a two-part can, may also optionally be given a finish coat in a coating station. At least the exterior lateral surface of each two-part can is primed, for example, particularly with a white primer. Once the printing on its lateral surface is complete, each two-part can is removed from its respective holder, for example, on the mandrel wheel, for example by means of compressed air or by means of a preferably reversible magnet, and is fed to at least one processing station situated downstream of the mandrel wheel, for example to an optional additional coating station, for coating the exterior lateral surface of each imprinted two-part can and/or to an edge processing station. The imprinted two-part cans are especially passed through a dryer, for example, a hot air dryer, to cure the at least one ink that has been applied to their respective lateral surfaces.
(17) The printing process for printing particularly on the lateral surface of each of the hollow bodies, more particularly two-part cans, held on the mandrel wheel, for example, begins with each of the inks that are required for the print image that will be printed onto the lateral surface of each hollow body being applied, for example by the respective printing plate of the plate cylinder, which is thrown, for example, onto the segmented wheel, onto the same one of the printing blankets arranged on the periphery of the segmented wheel. The printing blanket that has been inked up in this manner with all the required inks then transfers these inks simultaneously, by means of physical contact between the printing blanket and the lateral surface of the respective hollow body to be printed on, onto the lateral surface of this hollow body during a single revolution of the hollow body to be printed on, which is held on one of the mandrels of the mandrel wheel, about its own longitudinal axis. During the transfer of the inks from the printing blanket onto the lateral surface of the hollow body, the hollow body to be printed on, which is held by one of the mandrels of the mandrel wheel, for example, is rotated at a circumferential speed equal to that of the respective printing blanket arranged, for example, on the periphery of the segmented wheel. The respective circumferential speeds of hollow body and printing blanket or segmented wheel are thus synchronized with one another, with the hollow body to be printed on, which is held, for example, on one of the mandrels of the mandrel wheel, being accelerated appropriately from a stationary position, for example, beginning from its first point of contact with the printing blanket in question and continuing as its lateral surface rolls along a path of the first, e.g. 50 mm of the circumferential length of the printing blanket, particularly until it reaches the circumferential speed of the segmented wheel, for example. The segmented wheel that supports the printing blanket in question thus defines the circumferential speed to be adjusted at the respective mandrel of the mandrel wheel, for example. The circumferential speed of the printing forme cylinder that supports the printing forme or of the plate cylinder that supports the printing plate preferably also is or will be adjusted based on the circumferential speed of the segmented wheel, for example. The mandrel wheel and the segmented wheel are driven, for example, by the same central machine drive and are optionally coupled to one another mechanically, for example via a gear set. Alternatively, the mandrel wheel and the segmented wheel are each driven separately by an independent drive, and the rotational behavior of each is controlled, for example, by a control unit.
(18) In the following, various details relating to the above-described device for printing on or decorating hollow bodies in particular, each of which has a cylindrical lateral surface, for example, will be described by way of example, with reference to the aforementioned six figures. However, the individual assemblies specified below may also be used on or in printing machines and/or printing units other than the preferred embodiment discussed herein by way of example.
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(22) Printing forme cylinder 04, preferably embodied as a plate cylinder 04, and inking unit roller 08, preferably embodied as an anilox roller 08, are each independently rotationally driven by a motor 11; 12, for example, particularly in the preferred inking unit 06 as shown in
(23) In its preferred embodiment, ink forme roller 07 has a closed, preferably rubberized lateral surface. The lateral surface of inking unit roller 08, preferably embodied as anilox roller 08, is coated with a ceramic, for example, wherein a hachure of, for example, 80 lines per centimeter of axial length of anilox roller 08 or a saucer structure is formed in the ceramic layer. To enable the largest possible volume of ink to be fed into the roller train of inking unit 06 with each revolution of anilox roller 08, the outer diameter d08 of anilox roller 08 is preferably configured as larger than the outer diameter d07 of ink forme roller 07. Thus anilox roller 08 should have the greatest delivery volume possible. In
(24) In the preferred embodiment, at least the inking unit roller 08, preferably embodied as anilox roller 08, has a temperature control device for controlling the temperature of the lateral surface of said roller. The temperature control device of anilox roller 08 operates, for example, with a temperature control fluid that is introduced into the interior of anilox roller 08, wherein the temperature control fluid is water, for example, or some other liquid coolant. The temperature control device of anilox roller 08 can be used to influence the delivery volume of anilox roller 08, because it influences the viscosity of the ink to be transported by inking unit 06. The delivery volume of anilox roller 08 and the viscosity of the ink to be transported by inking unit 06 in turn ultimately impact the ink density of the ink to be applied to the cylindrical lateral surface of hollow body 01 to be imprinted. The thickness of the ink film formed by the ink to be applied to the cylindrical lateral surface of the hollow body 01 to be printed on is approximately 3 m, for example.
(25) The ink reservoir of inking unit 06 is embodied, as a chamber doctor blade system 09 that operates in conjunction with anilox roller 08. Advantageously, in this chamber doctor blade system 09 at least one ink trough, a doctor blade bar which is or at least can be placed axially parallel onto anilox roller 08, and preferably also a pump for conveying the ink form a single structural unit. This chamber doctor blade system 09 is held or mounted in inking unit 06, i.e. on a frame of inking unit 06, on only one side by means of a suspension, for example, so that this structural unit can be easily removed from inking unit 06 laterally after being released from the frame of inking unit 06, that is to say, by a movement directed axially parallel to anilox roller 08, for example by pulling on a handle arranged on this structural unit, and can thus be replaced. This structural unit of chamber doctor blade system 09 forms a cantilever arm on a side frame of inking unit 06.
(26) Once anilox roller 08 has received ink from the ink reservoir, i.e. in particular from chamber doctor blade system 09, anilox roller 08 transports this ink immediately and directly or via additional rollers of the roller train which is part of inking unit 06 to the preferably only one ink forme roller 07. In the direction of rotation of anilox roller 08, in an area downstream of chamber doctor blade system 09, which is placed against anilox roller 08, between chamber doctor blade system 09 and ink forme roller 07, a rider roller 13 preferably is or at least can be thrown onto anilox roller 08 for the purpose of improving the evenness of ink application to anilox roller 08 and the ink transport thereof. Rider roller 13 is arranged axially parallel to anilox roller 08. Rider roller 13 is not considered to be part of the roller train of inking unit 06 because it does not transfer ink from anilox roller 08 to any other roller. Rider roller 13, which is rotationally driven by anilox roller 08, e.g. by friction, has a rubberized lateral surface, for example. As rider roller 13, which is thrown onto anilox roller 08, rolls along the lateral surface of anilox roller 08, it draws a portion of the ink that has been received by anilox roller 08 from chamber doctor blade system 09 out of the hachure or the saucers of anilox roller 08 and applies at least some of this ink to lands formed on the lateral surface of anilox roller 08. Rider roller 13 rolling on anilox roller 08 thus causes anilox roller 08 to deliver a greater volume of ink to ink forme roller 07. In another sequence, with an anilox roller 08 having a temperature control device, for example, the effectiveness of controlling ink density is improved by rider roller 13 rolling on anilox roller 08 and contributing to supplying a greater volume of ink. Irrespective of the specific configuration of anilox roller 08, i.e., with or without a temperature control device, rider roller 13 rolling on anilox roller 08 therefore reduces both density differences that may occur as a result of manufacturing tolerances of anilox roller 08 and the risk that the hachure or saucers of anilox roller 08 may be visible on the printing substrate, i.e. in this case on the lateral surface of hollow body 01 to be printed on, as a result of an insufficient application of ink at least in patches.
(27) Particularly in a highly advantageous embodiment of the device for printing on hollow bodies, a plate changer 14 is provided, preferably in a fixed assignment to at least one, preferably to each printing forme cylinder, in particular plate cylinder 04, with which plate changer the printing forme intended for the printing forme cylinder in question, or the printing plate intended for the plate cylinder 04 in question can be replaced, preferably in an automated fashion, i.e. without intervention by operators, for example within the device in question for printing on or decorating hollow bodies 01, each of which has a cylindrical lateral surface in particular. With this plate changer 14, a printing forme intended for this printing forme cylinder 04 can be replaced within this device, from the side of the printing unit in question that lies diametrically opposite the side that holds the chamber doctor blade system 09 structural unit. In the device for printing on hollow bodies, plate changer 14 is arranged on the printing unit in question, assigned to the printing forme cylinder 04 thereof, which printing unit comprises inking unit 06 with the cantilevered structural unit of chamber doctor blade system 09, wherein the printing forme intended for this printing forme cylinder 04 is or at least can be supplied to this plate changer 14 from the side of the printing unit in question which is diametrically opposite the side that holds the structural unit of chamber doctor blade system 09.
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(29) In its preferred embodiment, in addition to bearing surface 16 for receiving a printing plate to be supplied in particular true to register to plate cylinder 04, for example, plate changer 14 has a compartment, for example, into which a printing plate removed from plate cylinder 04, for example, can be placed. A printing plate held by means of its carrier, for example, in particular magnetically on the lateral surface of the relevant plate cylinder 04 is or at least can be lifted off of the lateral surface of plate cylinder 04 in question, for example by means of a tool guided tangentially with respect to the printing forme, for example by means of a spatula guided between the carrier of the printing plate and the lateral surface of the plate cylinder 04 in question. The end of the relevant printing plate that has been lifted off of the lateral surface of plate cylinder 04 in question is inserted into the relevant compartment of plate cylinder 04 by a rotation of the plate cylinder 04 in question. By continuing this rotation of the plate cylinder 04 in question, the entire printing plate that has been separated from the lateral surface of plate cylinder 04 in question is then pushed into the relevant compartment of plate changer 14.
(30) A printing plate to be supplied, preferably true to register, to the plate cylinder 04 in question is held, particularly after being aligned true to register, by a magnetic holding force on bearing surface 16 of plate changer 14. At least one plunger, and preferably two plungers arranged spaced longitudinally along the plate cylinder 04 in question are provided, each having a direction of action directed opposite the magnetic holding force, with this direction of action being directed substantially orthogonally to bearing surface 16 of plate changer 14, for example. With this at least one plunger, at least one end of the printing plate held on bearing surface 16 of plate changer 14, said end facing the plate cylinder 04 in question, can be released from this bearing surface 16, and can be transferred to the plate cylinder 04 in question by a stroke movement of the at least one plunger. The at least one plunger is or at least can be actuated pneumatically, for example. The printing forme or the printing plate is held on bearing surface 16 of plate changer 14 or on the lateral surface of plate cylinder 04 by means of magnets, with each of these magnets preferably being embodied as a permanent magnet. The above-described configuration of plate cylinder 04 has the advantage that no conveyor device is required for transferring the printing plate to the relevant plate cylinder 04 or for removing the printing plate from the relevant plate cylinder 04, and therefore plate changer 14 can be implemented very cost-effectively. In particular, a plate change can be performed automatically using the plate changer 14 described above.
(31) The throwing on and/or throwing off of printing forme cylinder or plate cylinder 04, ink forme roller 07, and/or anilox roller 08, and/or the adjustment of the contact force exerted by each of these is carried out using a throw-on/throw-off mechanism, illustrated by way of example in
(32) In the preferred embodiment, ink forme roller 07 is also mounted particularly at both ends on a load arm of a preferably single-sided second lever assembly 23 consisting of a force arm and the load arm, wherein the force arm and the load arm of this second lever assembly 23 are pivotable together about the first rotational axis 19, which is aligned axially parallel to plate cylinder 04. In the preferred embodiment, inking unit roller 08, embodied, for example, as an anilox roller 08, is likewise mounted particularly at both ends on a load arm of a preferably single-sided third lever assembly 24 consisting of a force arm and the load arm, wherein the force arm and the load arm of this third lever assembly 24 are pivotable together about a second rotational axis 26, which is aligned axially parallel to anilox roller 08, and wherein the second rotational axis 26 of the third lever assembly 24 is disposed on the second lever assembly 23. The second rotational axis 26 is preferably embodied as fixed on the second lever assembly 23. On the load arm of the first lever assembly 18, a preferably controllable second drive 27 is arranged, which when operated, acts on the force arm of the second lever assembly 23, and which can be used to throw ink forme roller 07 onto or off of plate cylinder 04, depending on the operating direction of second drive 27. On the load arm of the second lever assembly 23, a preferably controllable third drive 28 is arranged, which when operated, acts on the force arm of the third lever assembly 24, and which can be used to throw anilox roller 08, preferably together with chamber doctor blade system 09, onto or off of ink forme roller 07, depending on the operating direction of third drive 28. Second drive 27 and/or third drive 28 are each also embodied as a hydraulic or pneumatic working cylinder, for example. It may be provided that second drive 27 and third drive 28 are or at least can be actuated together, for example, and preferably also simultaneously. The pivoting movement of the load arm of second lever assembly 23 is limited, for example, by a first stop system 29 which is preferably adjustable, particularly by means of an eccentric, whereby the contact force exerted by ink forme roller 07 against printing forme cylinder or plate cylinder 04 also is or at least can be limited. The pivoting movement of the load arm of third lever assembly 24 is limited, for example, by a second stop system 31 which is preferably adjustable, particularly by means of an eccentric, whereby the contact force exerted by anilox roller 08 against ink forme roller 07 also is or at least can be limited.
(33) While a preferred embodiment of a device for printing on hollow bodies in accordance with the present invention has been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that various changes could be made without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the appended claims.