DE102024111527A1 - Device for aligning magnetic or magnetizable particles - Google Patents

Abstract

The invention relates to a device for aligning magnetic or magnetizable particles contained in a coating material on a substrate, comprising a cylinder which is equipped, or can be equipped, with several magnetic field-providing units, hereinafter referred to as magnetic units, in the region of its outer circumference. The magnetic unit includes a holder supporting a magnet and a clamping mechanism with a clamping element radially movable on the side of the holder facing the interior of the cylinder. This clamping element has an outwardly directed clamping surface that engages an inwardly directed clamping surface of a support element provided on the magnetic cylinder. According to the invention, a spring element is provided that applies a force to the clamping element in the direction of the support element, as well as an actuating mechanism that counteracts this force during actuation.

Description

The invention relates to a device for aligning magnetic or magnetizable particles according to claim 1.

Through the EP 2 114 678 B1 A printing machine is known with a screen printing unit and a device for aligning magnetic or magnetizable particles contained in the printing ink or varnish, wherein the device comprises a cylinder with a plurality of magnetic field-generating elements on the circumference, which are arranged in several axially adjustable support rings.

The WO 2022/228822 A1 Disclosing a device for aligning magnetic or magnetizable particles contained in a coating material on a substrate, the device comprises a cylinder which is equipped, or can be equipped, with several magnetic units in the region of its outer circumference. Each magnetic unit includes a holder supporting a magnet and a clamping mechanism with a clamping element radially movable on the side of the holder facing the interior of the cylinder. In the assembled state, the clamping element engages behind a support element and can be positioned against the support element via a wedge drive.

The invention is based on the objective of creating an improved and/or alternative device for aligning magnetic or magnetizable particles.

The problem is solved according to the invention by the features of claim 1.

The advantages achievable with the invention consist in particular of the fact that the releasable fastening mechanism still enables a secure hold of the magnetic units while simultaneously allowing good handling.

A particular advantage is the self-locking design of the clamping mechanism as well as the easy-to-use operating mechanism for releasing the clamp.

After the application of printing ink containing magnetic or magnetizable particles, the particles are present in the ink matrix in a more or less disordered manner. By subsequently aligning one or more sub-areas to create an image motif or pattern within the previously printed area, hereinafter also referred to as image-forming alignment, at least some of the particles are specifically aligned in such a way that the desired optical effect is produced when viewing the printed image.

A particularly suitable device for aligning magnetic or magnetizable particles contained in a coating material on a substrate comprises a cylinder which is equipped or can be equipped with several magnetic field-providing units, hereinafter referred to as magnet units, in the region of its outer circumference, wherein the magnet unit comprises a holder carrying a magnet and a clamping mechanism with a clamping element radially movable on the side of the holder facing into the cylinder, which engages with an outwardly directed clamping surface a clamping surface facing into the cylinder of a support element provided on the magnet cylinder.

However, in order to be able to exchange and/or reposition the magnetic units for different productions and/or to readjust the position on the circumference, good and easy handling of the magnetic units during setup processes is of great importance.

In the embodiment according to the invention, the clamping mechanism is designed to be self-locking, wherein a spring element is provided which applies a force to the clamping element in the direction of the support element and an actuating mechanism which counteracts the force when actuated.

A radially movable arrangement includes, in particular, but not exclusively, the possibility of a strictly radial movement, i.e., movement in the radial direction, but also, for example, a movement along a direction with a significant, e.g., predominantly radial, movement component, i.e., a movement direction inclined at less than 45° to the radial direction, preferably at most 30°.

In an advantageous embodiment, the clamping element is arranged on a bolt which is radially movable in a recess of the holder and is further pre-tensioned towards the recess by the spring element.

In a preferred embodiment, the actuating mechanism comprises a cam carrier that can be pivoted about a pivot axis as an actuating means, which interacts directly or indirectly with the bolt as a tap element and together with it forms a cam drive.

A particularly preferable embodiment of a magnetic cylinder intended for the above-mentioned alignment comprises, in the region of its outer circumference, a matrix-like number of n x m (in words, n times m; with n, m ∈ ℕ) magnetic units, which are arranged one after the other in m in the circumferential direction of the The columns running along the cylinder and the rows running side by side in the axial direction are arranged.

In an advantageous embodiment, the magnetic units of one or more columns are each mounted as a group on or to a common support element and, together with the support element as a group, their axial position in or on the cylinder can be varied independently of the magnetic units of an adjacent column. In a further embodiment, in several of the columns of circumferentially arranged magnetic units, at least one of the magnetic units can be independently and axially adjustable on a one- or multi-part cylinder body of the cylinder, regardless of at least one other magnetic unit of the same column.

Further details and design variations can be found in the following examples.

Exemplary embodiments of the invention are shown in the drawings and are described in more detail below.

• 1 ein Ausführungsbeispiel für eine Maschine zur Erzeugung optisch variabler Bildelemente auf einem Substrat;
• 2 eine schematische Darstellung eines in Druckelementen mit optisch variablem Beschichtungsmittel bedruckten Substrates, wobei a) einen Zustand mit noch nicht orientierten magnetischen oder magnetisierbaren Partikeln und b) einen Zustand nach einem Ausrichten eines bildgebenden Teils zeigt, hier exemplarisch in Form einer Ziffer „1“;
• 3 eine schematische Darstellung eines Druck- und stromabwärtigen Ausrichtprozesses mit einem bildgebenden Druckwerkzylinder und einem Magneteinheiten aufweisenden Zylinder, beispielhaft dargestellt mit einem sich zum nachlaufenden Ende hin trapezförmig verbreiternden Substratbogen;
• 4 eine Schrägansicht einer Ausführung für einen Magneteinheiten aufweisenden Zylinder;
• 5 eine Einzeldarstellung a) eines in Umfangsrichtung hintereinander mit mehreren Magneteinheiten bestückten oder bestückbaren Tragelementes gemäß 4 und b) einer vergrößert dargestellten Magneteinheit aus a);
• 6 einen Schnitt durch einen Sockel der Magneteinheit aus 5 in radialer Richtung des Magnetzylinders betrachtet auf Höhe der Befestigungs- und Stellmittel;
• 7 einen in Umfangsrichtung verlaufender Längsschnitt durch eine Magneteinheit auf Höhe des Klemmmechanismus;
• 8 einen in Axialrichtung verlaufender Querschnitt durch eine Magneteinheit auf Höhe des Klemmmechanismus.

They show:

• 1 an embodiment of a machine for generating optically variable image elements on a substrate;
• 2 a schematic representation of a substrate printed in printing elements with optically variable coating medium, wherein a) shows a state with magnetic or magnetizable particles that are not yet oriented and b) shows a state after an imaging part has been aligned, here exemplified in the form of a number “1”;
• 3 a schematic representation of a printing and downstream alignment process with an imaging printing cylinder and a cylinder having magnetic units, exemplified by a substrate sheet that widens trapezoidally towards the trailing end;
• 4 an oblique view of a design for a cylinder containing magnetic units;
• 5 a single representation a) of a support element equipped or capable of being equipped with several magnetic units in the circumferential direction in succession according to 4 and b) an enlarged representation of a magnetic unit from a);
• 6 a section through a base of the magnet unit 5 viewed in the radial direction of the magnetic cylinder at the level of the fastening and adjusting means;
• 7 a longitudinal section running in the circumferential direction through a magnetic unit at the level of the clamping mechanism;
• 8 an axially extending cross-section through a magnetic unit at the level of the clamping mechanism.

A machine 01, e.g., a printing press 01, in particular a security printing press 01, for producing optically variable image elements 03 on a substrate 02, e.g., a web- or sheet-shaped printing material 02, comprises an application device 04, e.g., a printing unit 04, by which optically variable coating agent 06, e.g., optically variable printing ink 06 or varnish 06, can be applied at at least one application point, e.g., printing point, to at least one first side of the substrate 02, e.g., the printing material 02, either fully or partially, in the form of printed image elements 08, as well as a device 07 for aligning particles P contained in the optically variable coating agent 06 applied to the substrate 02 and responsible for the optical variability (see, e.g., 1 This device 07 will also be referred to below as alignment device 07 or, since it creates an image for the optically variable pattern or motif by defining the alignment of the particles P, also as imaging alignment device 07. An application of coating medium 06 containing particles P onto the substrate 02 and an image element 03 obtained by subsequent imaging alignment of previously randomly oriented particles P is, for example, 2 This is shown schematically using the number "1". Here, a) represents a state in which the coating material 06 has been applied and is, for example, still randomly oriented, and b) represents a state in which an image-forming alignment has taken place.

The printed image elements 08 made of variable coating material 06, applied to the substrate 02 by the application device 04 prior to treatment by the alignment device 07, can correspond in size and position to the optically variable image elements 03 to be produced, or may even be larger than them, and may even extend over the area in multiple uses 09. In the case of larger printed image elements 08, for example, an optically variable image element 03 is not produced on the entire area coated with optically variable coating material 06 by alignment.

The particles P responsible for the optical variability in the coating material 06, e.g., the printing ink 06 or the varnish 06, are magnetic or magnetizable, non-spherical particles. P, e.g. pigment particles P, hereinafter also referred to as magnetic flakes, are contained.

The machine 01 is preferably designed for the production of products 09, e.g., securities 09, in particular banknotes 09. This is intended to include, in particular, the production of intermediate securities products, e.g., the production of printing material 02, in particular in the form of web- or sheet-shaped printing material sections 02, especially printing material sheets 02, with printed images of several securities 09. The substrate 02 can be made of paper – e.g., cellulose-based or preferably cotton fiber-based or at least containing cotton fibers – of plastic polymers, or of a hybrid product thereof. It can be uncoated before coating in the aforementioned application unit 04, or it can already be coated; it can be unprinted or it can already be printed once or several times in one or more upstream processes or otherwise mechanically processed. On a substrate 02 formed by a longitudinal section of a web-shaped substrate 02 or by an arc of an arc-shaped substrate 02, several uses 09, e.g. banknotes 09 to be produced or their printed images, are preferably arranged in a matrix-like manner in rows running transversely to the transport direction T next to each other and in columns running one behind the other in the transport direction T, or arranged in the course of processing the substrate 02 (indicated e.g. in 2 and in 3 ).

The machine 01, designed as a printing machine 01, can in principle comprise one or more printing units 04 with one or more printing units 11; 12 of any printing process. In a preferred embodiment, however, it comprises a printing unit 04 with at least one printing unit 11; 12 operating according to the flexographic printing process or, preferably, according to the screen printing process, by which the optically variable coating agent 06 is or can be applied to a first side of the substrate 02. The aforementioned printing processes, in particular the screen printing process, allow, for example, a greater layer thickness to be applied compared to other printing processes. The term "first side" of the substrate 02 or the printing material 02 is chosen arbitrarily here and is intended to denote the side of the printing material 02 on which the optically variable coating agent 06, to be treated downstream by the alignment device 07, is or has been applied or can be applied.

In the illustrated and preferred embodiment, the printing machine 01 comprises a substrate feeder 13, e.g., a roll unwinder 13 or, more preferably, a sheet feeder 13, from which the substrate 02, e.g., web-shaped or preferably sheet-shaped, is fed—optionally via further printing or processing units—to the printing unit 04, e.g., a flexographic or, more preferably, a screen printing unit 04, which applies the optically variable coating agent 06, and which has at least one printing unit 11; 12, e.g., a flexographic or, more preferably, a screen printing unit 11; 12. In the illustrated and advantageous embodiment, two screen printing units 11; 12 are provided, which are preferably combined in the same printing unit 04 and are positioned between a printing cylinder 14; 16, e.g., a screen printing cylinder 14; 16, and a common counter-pressure cylinder 17 form two pressure points for the same, here first, side of the substrate 02 (see e.g. 1 ).

Preferably, the printing unit 11; 12 comprises a printing cylinder 14; 16 with a plurality of, in particular similar and/or identical, printing elements 18, hereinafter also referred to as printing images 18, or, in particular, similar and/or identical groups of printing elements 18 or printing images 18 on the circumference, which are arranged on a circumferential length corresponding to the length of the printing image in several, e.g., a number, e.g., four to eight, in particular five to seven, e.g., six, columns spaced apart from one another transversely to the transport direction T, and on a cylinder width corresponding to the width of the printing image in several lines spaced apart from one another in the transport direction T. In the case of a printing unit 11; 12 operating according to flexographic printing, these printing images 18 are designed in the form of relief prints, and in the preferred case of a printing unit 11; 12 operating according to screen printing, in the form of stencils.

The respective columns of image-forming print motifs 18 running circumferentially along the mold cylinder 14; 16 correspond to the same column of preprints 09 arranged or to be arranged sequentially on the substrate 02. Ideally, these preprints 09 are aligned with each other along the transport direction T and have a uniform width. In cases deviating from this, for example, if a trapezoidal deformation of the substrate 02, which was previously printed in the pattern of preprints 09, has occurred in an upstream process or due to other mechanical or physical stress, such a changed geometry can be compensated for by a correspondingly varied arrangement of the print motifs 18 on the mold cylinder 14; 16. In such cases, the print motifs 18 of individual columns do not, for example, align strictly with each other circumferentially, but lie, for example, partly on helical lines slightly inclined to the circumferential line (e.g., in a spiral pattern). 3 (Exaggerated for better perception). The width of the benefit 09 on substrate 02 decreases, for example, from the preceding to the trailing end of the substrate section or substrate sheet 02 or - e.g. with appropriate feed at the inlet of the printing press 01 - possibly vice versa.

The substrate 02 can be fed from the printing unit 04, which applies the optically variable coating agent 06, to the alignment device 07 via conveying means to a first conveying device 19. In the case of web-shaped substrate 02, this can be one or more positively driven and/or undriven rollers, over which the substrate 02 can be guided into the alignment device 07. In the preferred case of sheet-shaped substrate 02, i.e., individual sheets of substrate 02 passing through the printing unit 04, sheet-conveying means such as one or more transfer cylinders or drums, or, as shown, a conveying device 19 designed, for example, as a gripper conveyor 19, e.g., as a so-called chain gripper system 19, are provided as conveying means.

After passing through the alignment device 07, which is described in more detail below, the substrate 02 can be conveyed via conveying means of a further, e.g., a second conveying device 21, to a product receiving device 22 for receiving the substrate 02 processed and/or treated in the machine 01, e.g., a rewinder 22 in the case of web-shaped substrate 02 or a stack delivery device 22 in the preferred case of sheet-shaped substrate 02. In the case of web-shaped substrate 02, this can again be one or more positively driven or undriven rollers, which continue the transport path of the first conveying device 19 through the alignment device 07 and over which the substrate 02 can be guided into the rewinder 22 on the inlet side. In the preferred case of sheet-shaped substrate 02, sheet-conveying means are used as conveying means, e.g., a roller, a roller, or a roller. B. one or more transfer cylinders or drums or, as shown here, a conveying device 21 designed, for example, as a gripper circulation conveyor 21, in particular a chain gripper system 21, is provided, by which the printed material sheets 02 are taken from the transport path section of the alignment device 07 and fed, for example, to the stack delivery 22.

On the transport path leading away from the alignment device 07, at least one drying unit with one or more dryers 23 directed towards the first side of the substrate 02, e.g., radiation dryers 23, and optionally a cooling unit (not shown), e.g., a cooling roller, can be provided. In a further embodiment (not shown), an inspection unit (not shown), e.g., an area scan or line scan camera, can be provided on the transport path between the alignment device 07 and the stack delivery unit 22.

The alignment device 07, described in detail below, is in principle arbitrary in its designs, variants, or configurations, but is preferably provided or foreseen in a machine 01 or printing press 01 described above. In an advantageous embodiment, it is designed as a module and can be inserted into the transport path of the machine 01 to be equipped, with input and output interfaces to the open section ends of a conveyor system that continues upstream and downstream.

The alignment device 07 for forming optically variable image elements 03, e.g. for forming the optically variable effect into the previously - e.g. B. in the form of printed image elements 08 - applied to the substrate 02, in particular to the substrate 02, comprises a defined transport path along which the substrate 02 to be conveyed by the alignment device 07 is brought into operative contact in a defined manner with an alignment device 26, which comprises magnetic field-providing active units 24, hereinafter referred to as magnetic units 24, preferably such that the magnetic units 24 of the alignment device 26 serving the image-forming alignment and the substrate 02 printed with the printing ink 06 containing the particles P move synchronously to each other at least on a section of the transport path. Preferably, the alignment device 26 is designed as a magnetically effective cylinder 26, or magnetic cylinder 26 for short, which has an arrangement of magnetic units 24 on its circumference and over which the printing material 02 is guided or conveyed from an input area towards an output area of the alignment device 07.

The active units 24, designed as magnetic units 24, can be formed directly by active elements designed as magnets themselves, or preferably comprise one or more active elements 27 formed by magnets 27, which is/are arranged in or on a support element 28, in particular a holder 28, preferably detachably. Here, magnets 27 are generally understood to be magnetically active devices that are permanently or switchably magnetic, at least towards the side of the transport path, and are sufficiently strong, in particular for aligning particles P contained in the coating material 06 onto the substrate 02 guided above it as described here. The magnets 27 can be formed by one or more permanent magnets with or without engraving, by electromagnets, or by combinations of one or more permanent and/or one or more electromagnets. Regardless of whether it is a single magnet or a combination of several magnets, e.g., permanent and/or electromagnets, the term "magnet 27" in the following also refers to several magnets 27 belonging to the same magnetic unit 24 and forming a single functional unit, unless explicitly stated otherwise.

In principle, two such alignment devices 26, in particular cylinders 26, can also be provided in the transport path, which are arranged on the same or on different sides of a substrate 02 to be conveyed along the transport path.

In an advantageous embodiment, the alignment device 07 is associated with a drying and/or curing device 37, e.g. a radiation dryer 37, in particular a UV radiation dryer 37, or UV dryer 37 for short, which is preferably designed as a UV LED dryer 37 and/or is directed towards a point in the transport path where the substrate 02 interacts with the alignment device.

The alignment device 26, in particular the magnetic cylinder 26, is preferably arranged on the second side of the substrate 02 to be conveyed in the transport path, so that its first side, in particular coated upstream inline with optically variable coating medium 06, points outwards when passing the alignment device 26, in particular when transported over the magnetic cylinder 26.

The alignment device 26 comprises a single- or preferably multi-part cylindrical body 29, on or in which the magnetic units 24 are arranged – preferably detachably. In the preferred case of a cylinder 26 rotatably mounted in a frame, the cylindrical body 29 is formed, for example, by a single- or preferably multi-part cylindrical body 29. The term "cylindrical body 29" is intended to encompass both closed structures, i.e., with a more or less closed cylindrical surface, and open structures, i.e., framework- or frame-like structures such as, for example, the one described above. 4 The example presented includes...

The alignment device 26, preferably designed as a magnetic cylinder 26, has in the area of the side facing the substrate path, e.g. in the area of the outer circumference, in particular in the area of an outer cylindrical covering surface of the cylinder body 29, the plurality of magnetic units 24 which serve to orient at least a part of the magnetic or magnetizable particles P of the coating material 06 applied to the passing substrate 02.

In particular, for the case preferred and presented here of a plurality of uses 09 per substrate section, e.g. B. per substrate sheet 02, several columns or groups, each corresponding to the number of columns on the substrate section 02, are provided on the cylinder body 29, for example, viewed axially on the cylinder body 29, in particular a number m (m ∈ ℕ > 1) corresponding to the number of columns on the substrate section 02, each with several magnetic units 24 arranged one behind the other in the transport direction T of the substrate 02 and/or in the circumferential direction of the cylinder 26, in particular a number n (n ∈ ℕ > 1) corresponding to the number of rows of work 09 on the substrate section 02 to be treated, or a number n x m (in words n times m; with n, m ∈ ℕ) magnetic units 24 arranged in a matrix, preferably such that the same number n of magnetic units 24 are provided on the circumference for each column or group and are arranged in axially parallel rows and/or in such a way that they are unfolded on the Assuming a correct register between substrate position in transport direction T and cylinder angular position, substrate 02 corresponds to the pattern of the image elements 03 to be subjected to magnetic fields on substrate 02. The magnet units 24 of the groups, arranged one behind the other, are arranged circumferentially, in particular such that they at least overlap when unrolling along a circumferential line and/or lie in the same column 09 of a substrate 02 to be treated.

By guiding the substrate 02 over a magnetic cylinder 26 designed in this way, wherein, for example, the first side of the substrate faces outwards during transport over the first cylinder 26, it is possible to align or orient particles P in the area of the image elements 03 provided on the utility 09 by means of the magnetic units 24, here, for example, through the substrate 02.

The number m of groups is, for example, four to eight, particularly five and seven, e.g., six, and/or the number n of magnetic units 24 in a group is, for example, two to twelve, advantageously five to ten. The alignment device 26 or the cylindrical body 29 is preferably designed such that the number m of groups and/or the number n of magnetic units 24 arranged one behind the other in a group – for example, within the limits mentioned above – They are variable in order to adapt them to different requirements.

In a particularly advantageous further development, in order to be able to correct or, if necessary, deliberately vary random or systematic register deviations of individual magnetic units 24 to the substrate path, i.e., to the lateral position of the conveyed substrate 02, and/or to other magnetic units 24 relating to the same column of consecutive units 09 in the transport direction T, at least one of the magnetic units 24 in several of the circumferentially extending groups of magnetic units 24 is mounted in each of the magnetic units 24 in an axially adjustable or movable manner, in particular adjustable on the cylinder body 29 of the magnetic cylinder 26, independently of at least one other magnetic unit 24 of the same group. Preferably, several, advantageously at least all but one (i.e. at least n-1), but particularly advantageously all (i.e. n) magnetic units 24 of the same group are axially movable independently of other magnetic units 24 of the group and/or several, advantageously all but one (n-1) or all magnetic units 24 of at least the two end faces nearest to at least three groups are axially movable independently of other magnetic units 24 of the group in or on the cylinder body 29, in particular cylinder body 29.

For a matrix-like arrangement mentioned above, the magnetic units 24 can be arranged and mounted on or in a cylindrical body 29 such that at least the groups of magnetic units 24 of the same size are mounted on or in the single or multi-part cylindrical body 29 in a variable axial position relative to other magnetic units 24.

Preferably, the magnetic units 24 are detachably arranged or can be arranged on the cylinder 26 – preferably via a holder 28 encompassed by the respective magnetic unit 24 – such that, in the assembled state, they can be positioned at a defined location on the circumference of the cylinder 26 and preferably completely removable from the cylinder 26 and/or positioned axially and/or circumferentially on the circumference of the cylinder 26. For this purpose, the holder 28 comprises correspondingly detachable fastening means with, for example, a clamping mechanism 41, 56 and an actuating mechanism 39, 48, 61, which are described in more detail below.

The magnetic units 24 of a group are preferably variable in their axial position in the alignment device 26 or in the cylinder 26, independently of any adjacent group, with respect to the alignment device 26 or in the cylinder 26, in addition to any independent axial positioning of individual or all magnetic units 24 of the group. In particular, several groups, advantageously at least the two end-face closest to at least three groups, and advantageously all groups, are mounted axially movable in or on the cylinder body 29 in this way.

For this purpose, the magnetic units 24 are preferably arranged in or on several, e.g., a number m of four to eight, in particular five to seven, e.g., six, axially spaced apart from one another and preferably partially or preferably all of which can be positioned in the axial direction on an axis or shaft, e.g., ring elements 31, wherein several, e.g., two to twelve, advantageously five to ten, magnetic units 24 are again arranged or can be arranged in or on these ring elements 31 in the circumferential direction one behind the other and preferably at least partially or all of which can be positioned in the circumferential direction (see e.g., 4 The ring elements 31 are closed in the area of their outer circumference, for example by circumferential covers 32, e.g. covers 32 integrally connected with the ring ribs or attached cover plates 32, in which, for example, suction openings 33 and unlabeled recesses are provided at the respective location of the magnet units 24 (exemplarily indicated for a part of the right ring element 31 in 4 Alternatively, a cover plate 32 extending axially over all ring elements 31 can be provided, which includes the recesses and/or suction openings 33 at the relevant locations. The suction openings 33, in particular the suction channels 34 underneath them, are connected to a vacuum pump via, for example, a rotary feedthrough at the end face.

The magnetic cylinder 26 can be designed without any holding means acting on the substrate 02 in the case of a linear substrate 02, and, for example, with circumferentially closed ring elements 31. Optionally, suction air openings 33 can be provided on the circumference, which are connected to a vacuum pump and ensure that the substrate 02 rests securely on the cylinder's surface. In the preferred case of an arc-shaped substrate 02, holding means 36, e.g., grippers 36 of a so-called gripper bar, are preferably provided on the circumference of the cylinder 26. These grippers allow a substrate arc 02, to be conveyed over the cylinder 26, to be picked up by its leading end and held over an angular range during rotation of the cylinder 26. A magnetic cylinder 26 designed in this way simultaneously serves to transport the substrate 02. The ring elements 31 are, for example, interrupted in the circumferential direction as shown to accommodate the holding means 36.

In an advantageous embodiment, the at least one magnet 27 or a magnet arrangement is arranged on or in a holder 28. It can be contained in a housing 38 of the holder 28, which is, for example, in a 5 and 7 In the illustrated embodiment of the bracket 28, for example, it is detachably supported by a base 49 comprising the fastening means. In an alternative embodiment – without a specifically provided base 49 – the fastening means can be integrated in a region of the housing 38 located closer to the interior of the cylinder. In both embodiments, the housing 38 can include a removable cover 63, e.g., a removable lid 63.

In the case of intended axial mobility, the movement or positioning of the magnet 27 or of the magnet unit 24 comprising the magnet 27 and the holder 28 in the axial direction is preferably effected – in contrast to, for example, purely manual and/or tool-free movement – by means of actuating means 42, 43, 44, in particular mechanical means, in particular comprising a gear mechanism, with, for example, a gear mechanism that converts a rotational movement – in particular on the input side – into a linear movement – in particular of the magnet unit 24 or the holder 28 supporting the magnet unit 24 – e.g., directly or indirectly, preferably a screw drive, i.e., by means of a relative rotational movement between an internal and an external thread. Preferably, the relative rotational movement takes place about an axis or the thread axis extends along an axis that runs parallel to the axis of rotation of the cylinder 26.

In one embodiment (not shown), a threaded shaft with an external thread, extending with its longitudinal axis parallel to the cylinder 26 and rotatably but axially fixed to the cylinder body 29, can engage a threaded sleeve of the holder 28 with an internal thread and move the holder axially by rotating the threaded shaft. The threaded shaft can be designed as part of a screw, the end or middle section of which is formed by a screw head that can be actuated with a tool.

In another embodiment, a stop element can be provided to limit the axial movement of the magnetic unit 24 on one side. The stop surface of this stop, which limits the axial position, can be varied via a threaded drive. The magnetic unit 24 is preferably biased in the direction of the contact of the stop element by a force, e.g., a spring or pneumatic force, via a force-acting means 44. In one embodiment, such a stop element can, for example, be formed by an end, e.g., a screw head, of a threaded shaft with an external thread, which rotatably engages in a threaded sleeve provided on the cylinder body 29 or cylinder 26. The position of the stop, and thus of the magnetic unit 24, is adjusted by rotating the threaded pin, e.g., a screw, in one direction or the other.

In another context, for example here in 6 In the illustrated embodiment of the second variant, the stop is formed by an end of a threaded shaft 42 or an extension thereof, e.g., as the shaft and head of an adjusting screw 42, which rotatably engages in a threaded sleeve provided on the magnet unit 24 or on the bracket 28 and is supported axially against a fixed part of the cylinder body 29, e.g., a wall of the support element 31. The magnet unit 24 or the bracket 28 is preferably spring-loaded axially towards the contact of the stop. For this purpose, at least one stop 43, pre-tensioned by a resilient means 44, e.g., a compression spring 44, is provided on the side of the magnet unit 24 or the bracket 28 encompassed by it, as a force-acting means 43. B. A plunger 43 is provided, which, with an end projecting from the holder 28, bears against a fixed part of the cylinder body 29, e.g., an opposite wall of the support element 31. Preferably, two such plungers 43 are provided. By turning the adjusting screw 42 provided on one side of the magnet unit 24 or holder 28 in one direction, the magnet unit 24 or the holder 28 is moved further towards the side of the plunger(s) 43 against the spring force, while by turning it in the other direction, the magnet unit 24 or the holder 28 is moved further towards the side of the adjusting screw 42.

An adjustment range in the axial direction, viewed from a central position, is e.g. at least ± 1.0 mm (i.e. a total adjustment range of at least 2 mm), preferably at least ± 1.2 mm, e.g. ± 1.5 mm.

In a more convenient version, axial positioning of the relevant magnetic unit 24 can be achieved by a remotely controlled drive, e.g., an electric motor driving the threaded drive. In a less complex version, however, this can be done manually using a tool (not shown).

In an advantageous embodiment, the magnetic unit 24 or the holder 28 encompassed by it has fastening means - e.g. in a foot area - by means of which the magnetic unit 24 or the holder 28 is fastened. whose holder 28 can be fixed to the cylinder 26 or support element 31 and - in the case of axial adjustment and/or circumferential positioning - can be detached at least to the extent that the magnet unit 24 can be moved axially and/or circumferentially at least within the adjustment range.

Fundamentally independent of the above specific design of the magnetic cylinder 26 and/or of the above specific design of the magnetic units 24 and/or of the above axial adjustability and the means provided for this purpose, but preferably in conjunction with one or more of the above advantageous aspects for the design of the magnetic cylinder 26, the magnetic unit 24 and/or the adjustability, the magnetic units 24 are detachable and, viewed in the circumferential direction, variably positioned or positionable on the magnetic cylinder 26 - at least within certain limits of an adjustment range.

To enable the respective magnetic unit 24 to be easily and quickly detached and/or variably positioned circumferentially or, if applicable, axially, the fastening means comprise a clamping mechanism 41, 56, by which the magnetic unit 24 can be clamped to a cylinder-fixed support element 46 with a clamping force in a first operating state, namely in a ready-to-use working state, and in a second operating state, namely a setup state, the clamping mechanism 41, 56 is open or at least loosened, i.e., relieved of the clamping force. The clamping is closed or, preferably, opened via an actuating mechanism 39, 48, 61.

In a preferred embodiment, a clamping element 41, e.g., a clamping block 41, arranged radially movably on the side of the magnetic unit 24 facing the interior of the cylinder, engages with an outwardly directed clamping surface 51 a clamping surface 52 of a support element 46 provided on the magnetic cylinder 26, which faces the interior of the cylinder, so that the support element 46 is clamped in the operating state between a clamping surface 53 located in the area of the underside of the magnetic units 24 or its holder 28 and an outwardly directed clamping surface 54 of the clamping element 41. The term clamping surface 51; 52; 53; 54 is not only to be understood as large effective surfaces during clamping, as in the present case, but also as one or more small contact surfaces down to almost point-like areas, such as those effective, for example, in individual studs or claws. The clamping surface 53 located in the area of the underside of the bracket 28 can be provided on the underside of a housing 38 mentioned above or on a base 49 that may be additionally provided, depending on the design of the bracket 28.

The support elements 46 can, in principle, be formed by any single- or multi-part support structure with clamping surfaces 52 directed into the interior of the cylinder and engaged by the clamping elements 41. Preferably, however, they are formed by circumferential support ribs 46 extending preferably parallel to the circumference of the cylinder, which are encompassed by the ring- or ring-segment-like support element 31 or ring element 31, respectively, which support the magnet units 24 of a respective gap. Preferably, two axially spaced circumferential support ribs 46 are provided for each support or ring segment 31, between which the respective clamping element 41 extends and is supported from the inside against the inside of the respective support rib 46 with shoulders extending axially under the support ribs 46.

In a particularly preferred embodiment, the clamping mechanism 41, 56 is self-locking, i.e., such that when the actuating mechanism 39, 48, 61 is inactive, it is necessarily in a rest state in which the clamping is active or effective. This is achieved, for example, by the clamping element 41 being spring-biased in the direction of its clamping position, and the clamping can only be released by actuating the actuating mechanism 39, 48, 61. For this purpose, the clamping mechanism 41, 56 comprises, for example, a spring element 56, which is arranged and operatively connected to the clamping element 41 such that it exerts a force on the clamping element 41 in the direction of the underside of the support element. In particular, the spring element 56 is designed as a spring 56, e.g., B. A tension or preferably compression spring 56, designed to pull the clamping element 41 towards the underside of the support element 28 or – as is preferred here – to push it. In a preferred embodiment, the actuating mechanism 39, 48, 61 yields to the spring force that effects the clamping as soon as it is not actively held in the position required for opening.

In the advantageous embodiment shown here, the clamping element 41 is radially movably mounted in a recess 58 on the underside of the support element 28 via a bolt 57. The bolt 57 is surrounded on a longitudinal section lying in the recess 58, e.g., a bore 58, by a compression spring 56, which bears on one side against the side of a counter-bearing – e.g., annular and/or fixed to the support element – that points into the bore 58. The clamping element 41 is supported on the bolt 57 and on the other side against a support 59 encompassed by the bolt 57 – e.g., a disc-shaped support. In the rest state, the compression spring 56, e.g., as a disc spring 56 or disc spring assembly 56, thus presses the bolt 57 and therefore the clamping element 41 over the bolt-fixed support 59 towards the magnet unit 24, thereby introducing a clamping force directed towards the magnet unit 24 between the holder 28 of the magnet unit 24 and the clamping element 41.

As a result, the bolt 57 carrying the clamping element 41 and the recess 58 provided in the holder 28 form a kind of cylinder-piston system, wherein the bolt 57 forming the piston is pre-tensioned towards the inside of the cylinder by the spring 56 and can be displaced towards the outside by the actuating mechanism 39, 48, 61.

The clamping effected by the clamping device 41, 56 is preferably releasable by an actuating means 39 encompassed by the actuating mechanism 39, 48, 61, i.e. can be released against the spring force, so that the magnet unit 24 together with the clamping element 41 can be positioned in the circumferential direction or - e.g. after reaching an end of the support elements 46 or a section with a widening of the intermediate distance - can be removed.

In principle, an actuating mechanism based on any operating principle can be provided, provided that the actuating means 39 encompassed by the actuating mechanism 39, 48, 61 can transmit a movement opposite to the spring force to the bolt 57 or the abutment 59 encompassed by the bolt 57.

Preferably, however, a cam carrier 39, pivotable about a pivot axis S, is provided as the actuating means 39. This cam carrier interacts directly or indirectly with the bolt 57 as a tap element 57 via its circumference and together with the bolt 57 forms a cam drive 39, 57. The cam carrier 39 can be designed in the form of an eccentric, a cam, or a cam disk and can be supported by a pivotable shaft 61 and/or torsionally rigidly connected to such a shaft. Preferably, the pivot axis S runs parallel to the axis of rotation of the magnetic cylinder 26 and/or perpendicular to the direction of movement of the bolt 57 supporting the clamping element 41.

While pivoting the cam carrier 39 or the torsionally rigid shaft 61 connected to it can, in principle, be achieved in a more convenient design by means of a remotely controlled drive, e.g., an electric motor, in a less complex and preferred design this can be accomplished manually using a tool 48, e.g., a socket wrench 48, which corresponds to a tool interface 62, e.g., a recess 62, on the shaft 61.

In an advantageous further development of the magnet unit 24, the magnet 27 is replaced by, for example, a 7 The schematically indicated electric drive motor 68 is rotatable. For this purpose, the mounting 28, in the version of the mounting 28 with base 49, in particular the base 49 encompassed by it, includes an electrical interface 67, e.g. a terminal strip 67, which is in line connection on the output side with the drive motor 68 rotating the magnet 27 or its drive control, and can be connected or is connected on the input side with a signal and/or supply line 66 carrying electrical signals and/or power.

List of reference symbols

01

Machine for generating optically variable image elements, printing press, security printing press

02

Substrate, printing material, printing material section, printing material sheet, substrate sheet

03

Image element

04

Job setup, printing unit, flexographic printing unit, screen printing unit

05

-

06

Coating agent, printing ink, varnish

07

Device for aligning magnetic particles in image elements, alignment device

08

Print image element

09

Utility, security, banknote

10

-

11

Printing unit, flexographic printing unit, screen printing unit

12

Printing unit, flexographic printing unit, screen printing unit

13

Substrate template, roll unwinder, sheet feeder

14

Mold cylinders, screen printing cylinders

15

-

16

Mold cylinders, screen printing cylinders

17

Counterpressure cylinder

18

Printing element, printing subject

19

Conveyor system, gripper conveyor, chain gripper system

20

-

21

Conveyor system, gripper conveyor, chain gripper system

22

Product intake, rewinder, stacking delivery

23

Dryer, radiant dryer

24

Active unit, magnetic unit

25

-

26

Alignment device, cylinder, magnetic cylinder

27

Active element, magnet

28

Support element, bracket

29

Cylinder body

30

-

31

Supporting element, ring element

32

Cover, ceiling, cover plate

33

Suction opening

34

Suction channel

35

-

36

Holding devices, grippers

37

Drying and/or curing equipment, radiation dryer, UV radiation dryer, UV dryer, UV LED dryer

38

Housing

39

Actuating device, curve support

40

-

41

Clamping element, clamping block

42

Threaded shaft, adjusting screw

43

Center, stop, plunger

44

Medium, springy, compression spring

45

-

46

Support element, support rib

47

-

48

Tools, socket wrench

49

base

50

-

51

Clamping surface

52

Clamping surface

53

Clamping surface

54

Clamping surface

55

-

56

Spring element, spring, compression spring, disc spring, disc spring assembly

57

bolt, tap-off link

58

Recess, bore

59

abutment

60

-

61

Wave

62

Tool interface, recess

63

cover, lid

64

abutment

65

-

66

Signal and/or supply line

67

Electrical interface, terminal block

68

drive motor

P

Particles, pigment particles

T

Direction of transport

S

Swivel axis

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• EP 2 114 678 B1 [0002]
• WO 2022/228822 A1 [0003]

Claims (13)

Device (07) for aligning magnetic or magnetizable particles (P) contained in coating material (06) on a substrate (02) with a cylinder (26) which is equipped or can be equipped with several magnetic field-providing working units (24), hereinafter referred to as magnet units (24), in the region of its outer circumference, wherein the magnet unit (24) comprises a holder (28) carrying a magnet (27) and a clamping mechanism (41, 56) with a clamping element (41) arranged radially movably on the side of the holder (28) facing into the cylinder, which engages with an outwardly directed clamping surface (51) a clamping surface (52) facing into the cylinder of a support element (46) provided on the magnetic cylinder (26), characterized in that a spring element (56) acting on the clamping element (41) with a force acting in the direction of the support element (46) and an actuating mechanism opposing the force when actuated. (39, 48, 61) is provided. Device according to Claim 1 , characterized in that the clamping element (41) is arranged on a bolt (57) which is radially movable in a recess (58) of the holder (28) and is further pre-tensioned in the direction of the recess (58) by the spring element (56). Device according to Claim 2 , characterized in that the bolt (57) carrying the clamping element (41) is designed in the manner of a cylinder-piston system with the recess (58) provided in the holder (28), wherein the bolt (57) acting as a piston is subjected on the one hand to a preload acting further towards the recess (58) by the spring element (56) arranged in the recess (58) and can be displaced outwards against the spring force by actuating the actuating mechanism (39, 48, 61). Device according to Claim 2 or 3 , characterized in that the actuating mechanism (39, 48, 61) has as actuating means (39) a cam carrier (39) which can be pivoted about a pivot axis (S) and which cooperates directly or indirectly with the bolt (57) as a tap member (57) and together with it forms a cam drive (39, 57). Device according to Claim 4 , characterized in that the cam carrier (39) is designed in the form of an eccentric extending a shaft (61) or a cam arranged on a shaft (61) or a cam disk arranged on or on a shaft (61). Device according to Claim 4 or 5 , characterized in that the pivot axis (S) runs parallel to the axis of rotation of the magnetic cylinder (26) and/or perpendicular to the direction of movement of the bolt (57) supporting the clamping element (41). Device according to Claim 4 , 5 or 6 , characterized in that the cam carrier (39) is pivotable via a shaft (61) which has a tool interface (62) for the engagement of a corresponding tool (48) at an end projecting from the holder (28). Device according to Claim 1 , 2 , 3 , 4 , 5 , 6 or 7 , characterized in that the holder (28) on the side facing into the cylinder interior comprises a base (49) on which a housing (38) containing the magnet (27) is detachably arranged. Device according to Claim 8 , characterized in that the base (49) comprises an electrical interface (67) which is connected on the output side to a drive motor (68) rotating the magnet (27) and can be connected or is connected on the input side to a signal and/or supply line (66) carrying electrical signals and/or power. Device according to Claim 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 or 9 , characterized in that the cylinder (26) has in the region of its outer circumference a matrix-like number of nxm (in words n times m; with n, m ∈ ℕ > 1) such magnetic units (24) comprising a respective clamping mechanism (41, 56) which are arranged in n axially parallel rows and in m circumferentially extending columns, and that the magnetic units (24) of a respective column are arranged together on a support element (31) and, after releasing the respective clamping mechanism (41, 56) on the support element (31), can be varied in the circumferential direction over at least one adjustment range. Device according to Claim 10 , characterized in that the support elements (46) provided on the cylinder (26) for clamping the magnetic units (24) of the same gap are formed by two circumferential support ribs (46) running parallel to the circumference of the cylinder, which are arranged on the ring- or ring-segment-shaped support element (31) that carries the magnetic units (26) of the gap in question. Device according to Claim 10 or 11 , characterized in that the magnet units (24) of several or all columns mounted as a group on or at the common support element (31) are variable with respect to their axial position in or at the cylinder (26) together with the respective support element (31) as a group and independently of the magnet units (24) of an adjacent column. Device according to Claim 10 , 11 or 12 , characterized in that in several of the columns of circumferentially arranged magnetic units (24) at least one of the magnetic units (24) is arranged and/or mounted independently of at least one further magnetic unit (24) of the same column in an axially adjustable manner on the relevant support element (31).