Device for printing hollow bodies, and method for operating said device
10308008 ยท 2019-06-04
Assignee
Inventors
Cpc classification
B41F30/04
PERFORMING OPERATIONS; TRANSPORTING
International classification
B41F17/18
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A device for printing hollow bodies includes a segmented wheel which can be rotated about a rotational axis. The segmented wheel has multiple segments, one behind the other, on the segmented wheel circumference, each for receiving a respective printing blanket. At least one of the printing blankets, which is arranged on one of the segments, is arranged on the hollow body to be printed in a rolling manner or at least in a rollable manner. Each of the printing blankets is arranged on a plate-shaped metal support. Each plate-shaped metal support is configured to be bendable and forms a metal printing blanket, together with the printing blanket arranged on the support. Each metal printing blanket formed by the respective support, together with the printing blanket arranged on the support, is arranged or can at least be arranged on one of the segments of the segmented wheel in a replaceable manner as a whole. Each support, which is arranged on one of the segments of the segmented wheel, of the corresponding metal printing blanket, is held on the support in one of a form-fitting and a force-fitting manner.
Claims
1. A device for printing on hollow bodies comprising; a segmented wheel which is rotatable about a rotational axis, the segmented wheel having a periphery with a plurality of segments positioned one behind the other on the periphery, each segment being adapted to receive a printing blanket, wherein at least one of the printing blankets, which can be arranged on one of the segments, being arranged for one of rolling and being capable of rolling along the hollow bodies to be printed on, at least one of the printing blankets being arranged on a flexible, plate-shaped metallic substrate, wherein said flexible, plate-shaped metallic substrate, together with the at least one of the printing blankets arranged thereon, forms a metal printing blanket, wherein each of the metal printing blankets formed by the flexible, plate-shaped metallic substrate, together with the at least one of the printing blankets arranged thereon one of is and can be arranged, changeable as a complete unit, on one of the segments of the segmented wheel, wherein the flexible, plate-shaped metallic substrate of the metal printing blanket arranged on the one of the segments of the segmented wheel is held on this segment in one of a form-fitting connection and a force-fitting connection, wherein adjacent ones of the plurality of segments are each separated from one another by one of a plurality of recesses formed on the periphery of the segmented wheel, each of the plurality of recesses being aligned parallel to the rotational axis of the segmented wheel, wherein a leading edge of the flexible, plate-shaped metallic substrate of the metal printing blanket is bent at an acute angle in a direction of rotation of the segmented wheel, wherein, when the metal printing blanket is in the operating state, arranged on a segment of the segmented wheel, this bent leading edge of the flexible, plate-shaped metallic substrate is placed on a leading edge of one of the plurality of recesses formed on the periphery of the segmenting wheel, and in the direction of rotation of the segmented wheel, and wherein the bent leading edge of the substrate one of is and can be arranged in a form-fitting connection on this leading edge of the one of the plurality of recesses.
2. The device according to claim 1, wherein a device for automatically changing the metal printing blankets is provided, and is assigned to the segmented wheel.
3. The device according to claim 2, wherein the device for automatically changing the metal printing blankets is modular is construction and includes, as modules, a magazine for holding a plurality of the metal printing blankets, a first device for transporting the magazine vertically, and a second device for transporting the metal printing blankets horizontally, one at a time, between the magazine and one of the plurality of segments of the segmented wheel.
4. The device according to claim 3, wherein the second device, for transporting the metal printing blankets horizontally, includes a carriage, which carriage is movable bidirectionally between two end points, wherein the carriage one of transports and is capable of transporting a single metal printing blanket at a time.
5. The device according to claim 1, wherein a plurality of printing units are provided, wherein at least one of the printing units one of is and can be thrown onto at least one of the metal printing blankets arranged on the periphery of the segmented wheel, wherein at least one of the plurality of printing units includes a printing forme cylinder, and wherein a plate changer for automatically changing a printing forme on said printing forme cylinder is provided, and is assigned to the printing forme cylinder.
6. The device according to claim 5, wherein the plate changer has a bearing surface on which the printing forme that one of is and will be arranged on the printing forme cylinder can be placed, wherein the bearing surface is movable bidirectionally along a transport path between at least two defined positions, and wherein the printing forme to be arranged on the printing forme cylinder is placed on the bearing surface of the plate changer, true to register, with respect to its mounting position on the printing forme cylinder.
7. A machine arrangement for producing hollow bodies for filling, including a device for printing on the hollow bodies according to claim 1.
8. The machine arrangement according to claim 7, wherein the hollow bodies are one of made of one of metal, aluminum and plastic and wherein each of the hollow bodies is embodied as a two-part can.
9. The machine arrangement according to claim 7, wherein a mandrel wheel is located upstream of the device for printing on the hollow bodies in a direction of transport of the hollow bodies, wherein the mandrel wheel and the segmented wheel are each driven individually by a separate, dedicated drive, and wherein rotation of each of the mandrel wheel and the segmented wheel is controlled by a control unit.
10. A method for operating a device having a segmented wheel for printing on hollow bodies, including: providing a plurality of segments, one behind the other, on a periphery of the segmented wheel; arranging a metal printing blanket on at least one of the plurality of segments of the segmented wheel; rotating the segmented wheel, and rolling at least one metal printing blanket arranged on one of the segments along one of the hollow bodies to be printed on; providing a device for automatically changing metal printing blankets, assigned to the segmented wheel and having a magazine; using the device for automatically changing the metal printing blankets to automatically remove the metal printing blankets to be arranged on each of the plurality of segments of the segmented wheel from the magazine; providing a control unit for the device; and removing the metal printing blankets from the device for automatically changing the metal printing blankets, in response to a command issued to the control unit of said device; and transporting said blanket to the one of the segments of the segmented wheel.
11. The method according to claim 10, further including providing the device for automatically changing metal printing blankets having a device for transporting the metal printing blankets horizontally and having a movable carriage and transporting the metal printing blankets lying on the movable carriage.
12. The method according to claim 11, further including storing a plurality of the metal printing blankets in the magazine placing the metal printing blankets individually, one after the other, on the carriage of the device for transporting the metal printing blankets horizontally; and transporting the metal printing blankets, in succession, to one of the plurality of segments of the segmented wheel.
13. The method according to claim 11, further including using the device for alternatingly transporting the metal printing blankets, horizontally removed from one of the plurality of the segments of the segmented wheel, away from the segmented wheel and transporting a new metal printing blanket from the magazine to an unoccupied one of the plurality of segments of the segmented wheel.
14. The method according to claim 11, further including providing one of a sensory means and a switching element for determining whether a metal printing blanket to be removed from the magazine has been placed on the carriage of the device for horizontal transport.
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 below. Advantages to be achieved with the invention will be mentioned in connection with the exemplary embodiment.
(2) Shown are:
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DESCRIPTION OF PREFERRED EMBODIMENTS
(16) The printing, in particular, of the lateral surface of a hollow body with, e.g. a multicolor print motif, i.e. at least one printed image, is preferably carried out in a letterpress process. Alternative printing methods include, e.g., a screen printing process or an offset printing process or a digital printing process without printing formes. In the following, the invention will be described by way of example in connection with a letterpress process. To execute the letterpress process, a printing plate is arranged as a printing forme on the lateral surface of a plate cylinder. The printing plate ready for use in the printing process is a printing forme with a print relief, this print relief reproducing the print image intended for use in the printing process in a mirror image, i.e. mirrored. In an error-free printing 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 substrate of finite length, i.e. not annular and closed, ranging, e.g. from 250 mm to 900 mm, wherein said substrate is formed, e.g. from a steel sheet, and a printing element, in particular flexible, is disposed on said substrate. At least the opposing ends of the substrate in the circumferential direction of the plate cylinder may be either pre-curved, e.g. corresponding to the curvature of the lateral surface of the plate cylinder, or bent, to enable easier mounting of the printing forme, i.e. here in particular the printing plate, on the plate cylinder. The substrate 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 substrate, ranges from 0.7 mm to 1.0 mm, for example, and is preferably about 0.8 mm. The printing element is made of a plastic, for example. To produce the printing plate which is ready for use in the printing process, the printing element is exposed, e.g. with a negative film that mirrors the print image, and unexposed areas are then removed from the printing element, e.g. by washing or by means of a laser.
(17) 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, e.g. 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, in particular 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, e.g. on a preferably conical journal. Typically, only a single printing plate is arranged on the lateral surface of each plate cylinder, with the substrate 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 element 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 by means of its substrate, in particular magnetically, on the lateral surface of any of the plate cylinders, i.e. the printing forme or the printing plate is preferably held there magnetically, i.e. by means of a magnetic holding force. In an alternative or additional 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 configured as a printing unit that prints in a digital printing process without the use of printing formes, with such a printing unit having, in particular, at least one inkjet print head or one laser.
(18) The especially simultaneous transfer of a plurality of printing 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. A true-to-register arrangement of the printing forme or the printing plate on the lateral surface of the printing forme cylinder or plate cylinder in question requires the proper positioning of the printing forme in question or the printing plate in question in the axial direction and/or the circumferential direction of the printing forme cylinder or plate cylinder in question. To achieve this proper positioning, in the preferred embodiment, a plurality of register pins, e.g. the position of each being adjustable, are 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, in particular 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, in particular 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.
(19) Each printing forme cylinder, e.g. embodied as a plate cylinder, used in the printing process uses its printing forme or its printing plate to transfer a specific printing ink onto a printing blanket. The printing inks used are typically premixed, in particular specially customized inks, which are specifically adapted in terms of their respective printability to the material of the hollow body to be printed on, depending upon whether the surface to be printed on is made e.g. of aluminum, tinplate or plastic. In a preferred embodiment of a device for printing on or decorating hollow bodies, each of which has, e.g. a cylindrical lateral surface, a device for transferring printing 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 axis, wherein a plurality of printing blankets preferably are or at least can be arranged one behind 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 method that is used, the device for transferring printing 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 have hitherto been arranged on the periphery of the segmented wheel by attaching each of the printing blankets to the periphery of the segmented wheel, e.g. 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 segmented wheel in question. In a particularly preferred embodiment of a device for printing on or decorating hollow bodies, each of which has, e.g. a cylindrical lateral surface, a greater number of printing blankets are provided one behind 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 radially onto the segmented wheel. The device for transferring printing ink, preferably in the form of a carousel, in particular the segmented wheel, has a diameter of, e.g. 1,500 mm to 1,600 mm, preferably of about 1,520 mm to 1,525 mm, and when e.g. eight printing forme cylinders or plate cylinders are assigned to said device, it has e.g. twelve printing blankets arranged one behind the other around its periphery. The surface of each printing plate is preferably embodied as harder than 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 these printing forme cylinders or the respective printing plates of these plate cylinders roll along the printing blankets that are moved by the segmented wheel, with each of the printing plates pressing at least its print relief, e.g. 0.2 mm to 0.25 mm deep into the respective printing blanket, thereby producing a flattened area in the printing blanket in question, i.e. a roller strip, extending in the axial direction of the segmented wheel. The intensity of this flattening is or can be adjusted, e.g. prior to or at the start of a printing process, e.g. by means of remote actuation, by adjusting the contact pressure exerted by the printing forme cylinder or plate cylinder in question on the printing blanket in question of the segmented wheel.
(20) Each of the hollow bodies to be printed on here by way of example, e.g. each of the two-part cans to be printed on, is moved, e.g. 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 in a set cycle, 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 the printing zone 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, e.g. embodied as a feed wheel, up to at least one of the printing blankets arranged, e.g. on the segmented wheel, or each of the hollow bodies to be printed on is transported directly and immediately, i.e. without assistance from a device for transferring printing ink, e.g. embodied as a segmented wheel, into the respective printing zone of at last one of these printing units, which is the case in particular when the printing unit in question prints in a direct printing process, for example in an inkjet printing process.
(21) The feed wheel or mandrel wheel which, like e.g. the segmented wheel, rotates about a preferably horizontal axis, has a plurality of holders, e.g. 24 or 36, concentrically to its circumferential line in preferably equidistant distribution, e.g. each in the form of a clamping mandrel or a spindle that projects cantilevered from an end face of the mandrel wheel, wherein each holder holds or at least is capable of holding one of the hollow bodies to be printed on. A transport device embodied as a mandrel wheel is also characterized herein as a turntable with spindles. A mandrel wheel is described, e.g. in EP 1165318 A1. A description of suitable holders, spindles or clamping mandrels may be found in WO 2011/156052 A1, for example. In the following, each clamping mandrel will be referred to simply as a mandrel. The longitudinal axis of each mandrel is oriented parallel to the axis of the mandrel wheel. In the case involving printing on hollow bodies, each of which is embodied, e.g. as a two-part can, each of these hollow bodies is moved, e.g. by means of a conveyor device, e.g. a belt conveyor, up to the transport device, embodied e.g. as a mandrel wheel, where it is inverted at a transfer station onto one of the mandrels of the mandrel wheel by suction, e.g. 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, e.g. 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 to the mandrel wheel in rapid succession by the conveyor device. A conveyor device of this type is described, e.g. in EP 1132207 A1.
(22) A gap measuring 0.2 mm in width, for example, is preferably formed between the inner wall of a respective hollow body to be printed on and the surface of the relevant mandrel of the mandrel wheel, so that 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 about its respective longitudinal axis, e.g. by means of a preferably electric, controlled motor, and in particular is 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 a rotation that is or at least can be executed independently by the mandrel. The hollow body to be printed on is preferably inverted 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 rotational movement about its own longitudinal axis. The loading of each mandrel with a hollow body to be printed on is preferably verified, e.g. in a contactless manner by means of a sensor. If a mandrel is not loaded with a hollow body to be printed, the mandrel wheel will be moved, e.g. in such a way that contact of the unoccupied mandrel with a printing blanket of the segmented wheel is reliably prevented.
(23) Before being fed, e.g. to the mandrel wheel, two-part cans to be printed on are deep-drawn from a circular blank in a processing station disposed upstream of the mandrel wheel, this upstream processing station embodied as a deep-drawing device being located, e.g. in the same machine arrangement or production line as the device for printing on or decorating the hollow bodies, each having a lateral surface. In an additional processing station, in most cases also located in the same machine arrangement, the rim of each two-part can is trimmed at its open end face. In additional processing stations, in most cases also located in the stated machine arrangement, each two-part can is washed, for example, in particular its inside is washed out, and is optionally coated. At least the exterior lateral surface of each two-part can is primed, for example, in particular with a white primer. Once the printing on its lateral surface is complete, each two-part can is removed from its respective holder, e.g. on the mandrel wheel, e.g. by means of compressed air or by means of a preferably reversible magnet, and is fed to at least one processing station located downstream of the mandrel wheel, e.g. to a coating station for coating the exterior lateral surface of each printed two-part can and/or to a rim processing station. The printed two-part cans pass in particular through a dryer, e.g. a hot air dryer, to cure the at least one printing ink applied to their respective lateral surfaces, with all of these production steps preferably being carried out in the same machine arrangement, so that the two-part cans are manufactured completely in this machine arrangement, i.e. starting with a blank, i.e. the circular blank, and ending with a product ready for filling.
(24) The decoration, i.e. the printing process for printing in particular on the lateral surfaces of hollow bodies, in particular two-part cans, held, e.g. on the mandrel wheel, begins with each of the printing inks that are required for the print image to be printed onto the lateral surface of each hollow body being applied, e.g. by the respective printing plate of the plate cylinder that is thrown, e.g. onto the segmented wheel, to the same one of the printing blankets arranged on the periphery of the segmented wheel. The printing blanket in question, inked up in this manner with all the necessary printing inks, then transfers these printing inks simultaneously onto the lateral surface of the hollow body to be printed on by means of direct surface contact between the printing blanket and the lateral surface of the hollow body to be printed on during a single revolution of said hollow body to be printed on about its longitudinal axis, said hollow body being held on one of the mandrels of the mandrel wheel. During the transfer of the printing inks from the printing blanket onto the lateral surface of the hollow body, the hollow body to be printed on, held, e.g. by one of the mandrels of the mandrel wheel, rotates at the same circumferential speed as the printing blanket in question, arranged, e.g. 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, e.g. on one of the mandrels of the mandrel wheel, being accelerated appropriately, e.g. starting from a stationary position, beginning from its first point of contact with the relevant printing blanket 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, in particular until it reaches the circumferential speed, e.g. of the segmented wheel. The segmented wheel that carries the printing blanket in question therefore determines the circumferential speed to be set, e.g. at the respective mandrel of the mandrel wheel. The circumferential speed of the printing forme cylinder that carries the printing forme or of the plate cylinder that carries the printing plate also preferably is or will be adjusted based upon the circumferential speed, e.g. of the segmented wheel. The mandrel wheel and the segmented wheel are driven, e.g. by the same central machine drive and are optionally coupled to one another mechanically, e.g. via a gear set. Alternatively, the mandrel wheel and the segmented wheel are each driven separately by a separate, dedicated drive, and the rotation of each is controlled, e.g. by a control unit.
(25) In the following, various details relating, in particular, to the above-described device for printing on or decorating hollow bodies each of which has, e.g. a cylindrical lateral surface will be described by way of example, with reference to the aforementioned figures. However, the individual assemblies described 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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(28) Plate cylinder 04 and anilox roller 08 are each rotated, e.g. independently, each by a motor 11; 12, in particular in the preferred inking unit 06 as shown in
(29) In its preferred embodiment, ink forme roller 07 has a closed, preferably rubberized lateral surface. The lateral surface of anilox roller 08 is coated, e.g. with a ceramic, with a hachure, e.g. of 80 lines per centimeter of axial length of anilox roller 08 or a saucer structure being formed in the ceramic layer. To enable the largest possible volume of printing 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. Anilox roller 08 should thus have the greatest possible delivery volume. In
(30) In the preferred embodiment, at least anilox roller 08 has a temperature control device for controlling the temperature of the lateral surface of anilox roller 08. The temperature control device of anilox roller 08 operates e.g. using a temperature control fluid that is introduced into the interior of anilox roller 08, the temperature control fluid being, e.g. water 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, as said device influences the viscosity of the printing ink to be transported by inking unit 06. The delivery volume of anilox roller 08 and the viscosity of the printing ink to be transported by inking unit 06 in turn ultimately impact the ink density of the printing ink to be applied to the cylindrical lateral surface of the hollow body 01 to be printed on. The thickness of the ink film formed by the printing ink to be applied to the cylindrical lateral surface of hollow body 01 to be printed on is, e.g. about 3 ?m.
(31) The ink reservoir of inking unit 06 is embodied, e.g. 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 set axially parallel against anilox roller 08, and preferably also a pump for delivering the printing ink form a single structural unit. This chamber doctor blade system 09 is preferably 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 once this modular unit has been released from the frame of inking unit 06 it can be removed from inking unit 06 in a simple manner laterally, i.e. by a movement directed axially parallel to anilox roller 08, e.g. by pulling on a handle disposed on said structural unit, and can thereby be replaced in a simple manner, in particular without the use of tools. This modular unit of chamber doctor blade system 09 preferably forms a cantilever arm on a side frame of inking unit 06.
(32) Once anilox roller 08 has received printing ink from the ink reservoir, i.e. in particular from chamber doctor blade system 09, anilox roller 08 transports this printing 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 a region downstream of the chamber doctor blade system 09, which is set against anilox roller 08, between chamber doctor blade system 09 and ink forme roller 07 in the direction of rotation of anilox roller 08, a rider roller 13 preferably is or at least can be thrown onto anilox roller 08 for the purpose of improving the transport of ink by anilox roller 08. 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 printing ink from anilox roller 08 to another roller. Rider roller 13, which is rotationally driven by anilox roller 08, e.g. by means of 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 printing 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 deposits at least some of this printing ink onto lands that are formed on the lateral surface of anilox roller 08. Rider roller 13 rolling along anilox roller 08 thus causes anilox roller 08 to deliver a greater volume of printing ink to ink forme roller 07. As a further consequence, an anilox roller 08 that includes, e.g. a temperature control device also improves the efficacy of controlling the ink density in that the rider roller 13 rolling along anilox roller 08 contributes to supplying a greater volume of printing ink. Regardless of the specific configuration of anilox roller 08, i.e. with or without a temperature control device, rider roller 13 rolling along anilox roller 08 thus reduces both differences in density that can arise due to manufacturing tolerances of the anilox roller 08 and the risk of the hachure or saucers of anilox roller 08 being visible on the printing substrate, i.e. in this case on the lateral surface of the hollow body 01 to be printed on, due to an insufficient application of ink, at least in some areas.
(33) In particular in a highly advantageous embodiment of the device for printing on hollow bodies, a plate changer 14 is provided, e.g. for each printing forme cylinder, in particular plate cylinder 04, preferably in a fixed assignment thereto, 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 automatically, within e.g. the relevant device for printing on or decorating hollow bodies 01, each having in particular a cylindrical lateral surface.
(34) In its preferred embodiment, in addition to bearing surface 16 for receiving a printing plate to be supplied, in particular true to register, e.g. to plate cylinder 04, plate changer 14 has, e.g. a compartment in which, e.g. a printing plate that has been removed from plate cylinder 04 may be placed. A printing plate held, e.g. by means of its substrate, in particular magnetically, on the lateral surface of the plate cylinder 04 in question is or at least can be lifted off of the lateral surface of the plate cylinder 04 in question, e.g. by means of a tool guided tangentially to the printing forme, e.g. by means of a spatula guided between the substrate of the printing plate and the lateral surface of the plate cylinder 04 in question. The end of a printing plate that has been lifted off of the lateral surface of the plate cylinder 04 in question is introduced by a rotation of the plate cylinder 04 in question into the appropriate compartment of plate cylinder 04. The further rotation of said plate cylinder 04 then pushes the entire printing plate detached from the lateral surface of the relevant plate cylinder 04 into the appropriate compartment of plate changer 14.
(35) A printing plate to be supplied, preferably true to register, to the plate cylinder 04 in question is held, in particular after being aligned true to register, on bearing surface 16 of plate changer 14 by a magnetic holding force. At least one plunger, and preferably two plungers arranged spaced apart longitudinally along the plate cylinder 04 in question, is/are provided, each having a direction of action directed opposite the magnetic holding force and toward bearing surface 16 of plate changer 14, e.g. substantially orthogonal thereto; with said 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 detached from said bearing surface 16 and can be transferred to the plate cylinder 04 in question by way of 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 realized very inexpensively. In particular, a plate change is or at least can be carried out automatically using the plate changer 14 described above.
(36) 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 pressure exerted by each of these is carried out by means of a throw-on/throw-off mechanism, illustrated by way of example in
(37) In the preferred embodiment, ink forme roller 07 is also mounted, in particular at both ends, on a load arm of a preferably one-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 jointly about the first rotational axis 19, which is aligned axially parallel to plate cylinder 04. Likewise in the preferred embodiment, anilox roller 08 is also mounted, in particular at both ends, on a load arm of a preferably one-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 jointly about a second rotational axis 26, which is aligned axially parallel to anilox roller 08, wherein the second rotational axis 26 of the third lever assembly 24 is located on the second lever assembly 23, and wherein the second rotational axis 26 is 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 actuated 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 upon the direction of action of second drive 27. On the load arm of the second lever assembly 23, a preferably controllable third drive 28 is arranged, which when actuated 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 upon the direction of action of third drive 28. The second drive 27 and/or the third drive 28 is/are each also embodied, e.g. in the form of a hydraulic or pneumatic working cylinder. It may be provided that second drive 27 and third drive 28 are or at least can be actuated, e.g. jointly and preferably also simultaneously. The pivoting movement of the load arm of the second lever assembly 23 is limited, e.g. by a first stop system 29 which is preferably adjustable, in particular by means of an eccentric, whereby the contact pressure exerted by ink forme roller 07 against the printing forme cylinder or plate cylinder 04 is or at least can be limited. The pivoting movement of the load arm of the third lever assembly 24 is limited, e.g. by a second stop system 31 which is preferably adjustable, in particular by means of an eccentric, whereby the contact pressure exerted by anilox roller 08 against ink forme roller 07 also is or at least can be limited.
(38) As described above and as shown in
(39) As a solution, it is proposed to provide a device, assigned to segmented wheel 03, for automatically changing the printing blankets 33. In the preferred embodiment, each of these printing blankets 33 to be arranged on segmented wheel 03 is applied adhesively, in particular by gluing, to a preferably flat, tabular metal substrate having a material thickness of, e.g. 0.2 mm. Each preferably magnetizable metal substrate is then arranged, together with the printing blanket 33 disposed thereon, in particular in the proper position on one of the segments 32 on the periphery of segmented wheel 03, e.g. by means of at least one of the holding magnets provided there on the periphery for each blanket 33 or the substrate thereof. To support the arrangement of each metal substrate in the proper position on the appropriate segment 32 on the periphery of segmented wheel 03, an acutely angled mounting arm 38 is provided, e.g. at the leading edge 37 of the respective metal substrate in the direction of rotation of segmented wheel 03, and when the respective metal substrate is arranged on one of the segments 32 on the periphery of segmented wheel 03, this mounting arm 38 engages into a recess 36 formed on the periphery of this segmented wheel 03, aligned parallel to the rotational axis 34 thereof and embodied, e.g. as a groove, and comes to rest, in particular in a form-fitting connection, on a leading edge 39 of the recess 36 in question in the direction of rotation of segmented wheel 03. Each of the printing blankets 33 is preferably embodied as a rubber blanket. The direction of rotation of segmented wheel 03 during the printing process is indicated in
(40) The device for automatically changing the printing blankets 33 is preferably modular in construction and includes as modulesas shown by way of example in
(41) The replacement or changing of at least one of the printing blankets 33 arranged on the periphery of segmented wheel 03 is then preferably carried out as follows:
(42) Segmented wheel 03 rotates a printing blanket 33 which is arranged on the periphery of said wheel and is to be removed, into a rotational angle position at which a removal of said printing blanket 33 can be carried out by means of the device for automatically changing the printing blankets 33. This rotational angle position is, e.g. the nadir of segmented wheel 03, or is at least close to the bottom of segmented wheel 03, e.g. within an angular range of ?45? from the nadir. Carriage 46 of the device 44 for transporting printing blankets 33 horizontally travels along its travel path up to the end point which is closest to the removal point of the printing blanket 33 to be removed. This position of carriage 46 associated with the removal point is preferably monitored by sensory means and/or by a first switching element 48, e.g. by means of an inductive or capacitive proximity switch. Spatula 47 is then preferably set against the trailing edge 37, in the direction of rotation of segmented wheel 03, of the metal substrate of the relevant printing blanket 33 to be removed. By rotating segmented wheel 03 at least briefly in the direction opposite its direction of rotation used during the printing process, the printing blanket 33 to be removed, which is preferably held magnetically on the periphery of segmented wheel 03, is peeled off of the periphery of said segmented wheel 03, i.e. the metal substrate of printing blanket 33 is lifted away from its position resting on segmented wheel 03 by means of spatula 47. Spatula 47 is then moved away from the periphery of segmented wheel 03. The printing blanket 33 that has been detached from the relevant segment 32 of segmented wheel 03 then either drops by virtue of gravity directly into a magazine for worn printing blankets 33 or is transported to said magazine for worn printing blankets by means of carriage 46 of the device 44 for transporting printing blankets 33 horizontally.
(43) A new printing blanket 33 glued to a metal substrate is loaded in at least one compartment, preferably in each of the compartments of the magazine 42 provided for a plurality of new printing blankets 33 and said magazine 42 is preferably located in a raised upper position by means of the device 43 for vertical transport thereof. The carriage 46 of the device 44 for horizontally transporting one printing blanket 33 at a time between magazine 42 and the mounting position on segmented wheel 03 is situated beneath the compartment that contains the new printing blanket 33. The device 43 for vertical transport lowers this magazine 42, thereby placing the new printing blanket 33 onto carriage 46 of the device 44 for horizontal transport. The process is monitored, preferably by sensory means and/or by a second switching element 49, e.g. by means of an inductive or capacitive proximity switch, to determine whether the new printing blanket 33 has actually been placed on carriage 46 of the device 44 for horizontal transport. If not, an error message is issued. Otherwise, i.e. if no error is detected, carriage 46 of the device 44 for transporting printing blankets 33 horizontally moves along its travel path up to the end point closest to the mounting position for the new printing blanket 33, with this position of carriage 46 associated with the mounting position in turn being monitored, preferably by sensory means and/or by a third switching element 51, e.g. by means of an inductive or capacitive proximity switch. Segmented wheel 03 is also already located in a rotational angle position suitable for receiving the new printing blanket 33, with this rotational angle position being located, e.g.as beforeat or near the bottom of segmented wheel 03. In the preferred embodiment, the position of the new printing blanket 33 is aligned at least true to register by said printing blanket abutting against at least stop 52, before being mounted on the periphery of segmented wheel 03. For moving carriage 46 of the device 44 for transporting printing blankets 33 horizontally, a drive is provided, said drive being embodied, e.g. as a compressed air cylinder. To mount the new printing blanket 33 on the periphery of segmented wheel 03, said segmented wheel 03 rotates in the direction of rotation used during the printing process, thereby drawing the new printing blanket 33 up onto its periphery. Carriage 46 of the device 44 for transporting printing blankets 33 horizontally is then moved back to the magazine 42 for the plurality of new printing blankets 33, to retrieve another new printing blanket 33, if necessary.
(44) To reduce set-up times at a decorator, a device for printing on hollow bodies 01 is now proposed, which includes a segmented wheel 03 which is rotatable about a rotational axis 34, wherein segmented wheel 03 has a plurality of segments 32 one behind the other on its periphery, each for receiving one printing blanket 33, wherein at least one of the printing blankets 33 located on one of the segments 32 is arranged to roll or at least to be capable of rolling along the hollow body 01 to be printed on, wherein a plurality of printing units are provided, wherein at least one of the printing units is or at least can be thrown onto at least one of the printing blankets 33 arranged on the periphery of segmented wheel 03, wherein at least one of the printing units includes a printing forme cylinder 04, wherein in association with the relevant printing forme cylinder 04, a plate changer 14 for automatically changing a printing forme is located on said printing forme cylinder 04, and wherein in association with segmented wheel 03, a device for automatically changing at least one of the printing blankets 33 arranged on the periphery of said segmented wheel 03 is provided. Said plate changer 14 preferably has a bearing surface 16, onto which the printing forme that is or will be arranged on printing forme cylinder 04 can be placed, said bearing surface 16 being movable bidirectionally along a transport path between at least two defined positions. The printing forme to be supplied to the printing forme cylinder 04 in question is held, e.g. by a magnetic holding force on the bearing surface 16 of plate changer 14. The device for automatically changing the printing blankets 33 is modular, in particular, and includes as modules a magazine 42 for a plurality of printing blankets 33, along with a device 43 for vertically transporting said magazine 42, and a device 44 for horizontally transporting one of the printing blankets 33 at a time between magazine 42 and one of the segments 32 of segmented wheel 03. Magazine 42 has a plurality of vertically stacked compartments, in each of which a single printing blanket 33 is or at least can be stored, within a housing. Each of the printing blankets 33 is preferably stored lying on its back and/or in a horizontal alignment in magazine 42. Device 43 for vertically transporting magazine 42 is configured to execute, e.g. a lifting movement, and/or device 44 for transporting printing blankets 33 horizontally has a carriage 46 which is movable bidirectionally between two endpoints, wherein a single printing blanket 33 is or at least can be transported at a time by carriage 46. Plate changer 14 and the device for automatically changing the printing blankets 33 are each controlled, e.g. by a control unit, wherein in a preferred embodiment, plate changer 14 and the device for automatically changing printing blankets 33 are active at the same time, and each carries out its changing of a printing plate or a printing blanket 33 during the same interruption in the production process being run on this device for printing on hollow bodies 01. The printing forme to be arranged on printing forme cylinder 04 is preferably arranged on bearing surface 16 of plate changer 14 true to register with respect to its mounting position on printing forme cylinder 04, and/or the printing blanket 33 to be arranged on the periphery of segmented wheel 03 is arranged on the carriage 46 of the device 44 for transporting printing blankets 33 horizontally in the correct position with respect to its mounting position on a segment 32 of segmented wheel 03. An inking unit 06 for transporting printing ink to printing forme cylinder 04 is preferably embodied as a short inking unit that includes an anilox roller 08.
(45) With respect to a device for printing on hollow bodies 01, which includes a segmented wheel 03 that is rotatable about a rotational axis 34, wherein the segmented wheel 03 has a plurality of segments 32 on its periphery, each for receiving a printing blanket 33, wherein at least one of the printing blankets 33 arranged on one of the segments 32 is arranged rolling or at least capable of rolling along the hollow body 01 to be printed, wherein every two adjacent segments 32 are separated from one another by a recess 36 aligned parallel to the rotational axis 34 of segmented wheel 03, it is also proposed that each of the printing blankets 33 is disposed on a plate-shaped metallic substrate, wherein the substrate along with the printing blanket 33 disposed thereon is or at least can be arranged as such, and replaceable in its entirety, on one of the segments 32 of segmented wheel 03, wherein the substrate arranged on one of the segments 32 of segmented wheel 03 is held on this segment 32 in a form-fitting and/or in a force-fitting connection. Each substrate of a printing blanket 33 is bent, preferably at an acute angle, at its leading edge 37 in the direction of rotation of segmented wheel 03, wherein when said substrate is located in the operating position on a segment 32 of segmented wheel 03, this bent edge 38 is placed at a leading edge 39, in the direction of rotation of segmented wheel 03, of the appropriate recess 36 formed on the periphery of segmented wheel 03, wherein the bent edge 38 of the substrate is or at least can be arranged in a form-fitting connection on this edge 39 of recess 36. The plate-shaped metallic substrate is embodied in particular as flexible, and together with the printing blanket 33 arranged on it forms, e.g. a metal printing blanket. The substrate arranged on one of the segments 32 of segmented wheel 03 is held on this segment 32 by a magnetic force. A plurality of segments 32, e.g. eight to twelve, each for receiving one printing blanket 33, are arranged one behind the other on the periphery of segmented wheel 03. Assigned to segmented wheel 03, e.g. a device for automatically changing printing blankets 33 is provided, wherein the device for automatically changing printing blankets 33 is preferably modular in construction, and includes as modules a magazine 42 for a plurality of printing blankets 33 along with a device 43 for vertical transport of the aforementioned magazine 42 and a device 44 for horizontal transport of one of the printing blankets 33 at a time between magazine 42 and one of the segments 32 of segmented wheel 03. Magazine 42 has in particular a plurality of compartments stacked vertically within a housing, in each of which a single printing blanket 33 is or at least can be stored. The housing of magazine 42 contains e.g. at least as many compartments as the number of segments 32 for printing blankets 33 on the periphery of the associated segmented wheel 03. In the preferred embodiment, the device 43 for vertically transporting magazine 42 is configured to execute a lifting movement, and/or device 44 for transporting printing blankets 33 horizontally has a carriage 46 which is movable bidirectionally between two endpoints, wherein a single printing blanket 33 is or at least can be transported at a time by carriage 46.
(46) This also results in a method for operating a device for printing on hollow bodies 01 which has a segmented wheel 03, wherein a printing blanket 33 is arranged on at least one segment 32 of the segmented wheel 03, which has a plurality of segments 32 one behind the other on its periphery, wherein when the segmented wheel 03 rotates, at least one printing blanket 33 arranged on one of the segments 32 rolls along the hollow body 01 to be printed on, wherein a device for automatically changing printing blankets 33, assigned to segmented wheel 03, in response to a command issued to its control unit, automatically removes the printing blanket 33 to be arranged on the relevant segment 32 of the segmented wheel 03 from a magazine 42, and transports it to the segment 32 in question of segmented wheel 03. The device for automatically changing printing blankets 33 has a device 44 for horizontally transporting printing blankets 33, with a movable carriage 46, wherein each of the printing blankets 33 to be transported is transported lying on carriage 46. A printing blanket 33 lying on carriage 46 is preferably arranged in the proper position and/or true to register with respect to a mounting position on one of the segments 32 of segmented wheel 03. A plurality of printing blankets 33 in particular are stored in magazine 42, and these printing blankets 33 are placed individually, one after the other, on carriage 46 of the device 44 for transporting printing blankets 33 horizontally, and are transported in succession to one of the segments 32 of segmented wheel 03. A printing blanket 33 to be arranged on one of the segments 32 of segmented wheel 03 is arranged on the segment 32 in question, in particular by means of a form-fitting connection produced between the relevant segment 32 and the printing blanket 33 by a rotation of this segmented wheel 03. A printing blanket 33 arranged on one of the segments 32 of segmented wheel 03 is preferably held on the segment 32 in question, e.g. by a magnetic force connection. A printing blanket 33 that has been removed from one of the segments 32 of segmented wheel 03 is likewise preferably transported away from the segmented wheel 03 in question by the device 44 for transporting printing blankets 33 horizontally. It is preferably provided that the device 44 for transporting printing blankets 33 horizontally alternatingly transports a printing blanket 33 that has been removed from one of the segments 32 of segmented wheel 03 away, and transports a new, i.e. unused printing blanket 33 from magazine 42 to an unoccupied segment 32 of segmented wheel 03, i.e. to a segment 32 on which no printing blanket 33 is currently arranged. A switching element 49 monitors the process, e.g. to determine whether a printing blanket 33 removed or to be removed from magazine 42 has actually been placed on carriage 46 of the device 44 for horizontal transport, and/or whether it has been placed in the proper position.
(47) While preferred embodiments of a device for printing on hollow bodies and a method for operating such a device, in accordance with the present invention, have been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that various changes could be made thereto without departing from the true spirit and scope of the present invention, which is accordingly to be limited only by the appended claims.