Assembly of printheads and method for adjusting printheads

Abstract

The invention relates to an assembly of printheads in a plane, comprising at least two linear guides, a plurality of printheads, a plurality of connection elements and connection points. The linear guides are connected at the ends thereof by means of cross-supports. The printheads are disposed in one or more rows between the linear guides. Each of the connection elements is disposed on one of the linear guides so as to be movable along said linear guide. At each of the connection points, up to two adjacent printheads of a row are releasably attached. At least one connection element of a row has a releasable fastening means, by means of which the row is releasably fastened against movement along the corresponding linear guide. The invention also relates to a method for adjusting a row of printheads and to a method for adjusting printhead distances in a row in an assembly of this type.

Description

[0001] ARRANGEMENT OF PRINTHEADS AND METHOD FOR ADJUSTING PRINTHEADS

[0002] The invention relates to an arrangement of print heads and methods for adjusting print heads.

[0003] Print heads, especially for inkjet printers (so-called inkjet print heads), must be assembled with extreme precision to ensure high-quality print results. Permissible tolerances are in the range of a few micrometers (pm). Especially for arrangements of multiple print heads, precisely manufactured mounting plates are currently used to keep the distances between the print heads constant. The print heads are sometimes arranged in modules. For large modules that accommodate numerous print heads, complex milled parts are required that must be manufactured with high precision. Static requirements and limited permissible thermal expansion require special materials and result in high costs. The adjustability of the heads to one another and, depending on the head type, also at an angle to the printing direction must be guaranteed.If one or more print heads need to be replaced because they are defective, or if the positions need to be corrected over time due to mechanical stress, these adjustments can sometimes take several days and require qualified specialists to carry out the adjustments.

[0004] AT522339 describes an arrangement for positioning print heads to create a print image in a printing plane, wherein the printing plane is movable relative to the print heads in a direction of movement of the printing planes. The print heads are arranged in a geometric chain and coupled via connecting elements that exclusively connect adjacent print heads. The connecting elements each comprise at least one detachable coupling connection to the adjacent print head for adjusting the distance between two adjacent print heads, wherein the print heads and / or the connecting elements are adjustably mounted by means of a guide in a plane parallel to the printing plane. A disadvantage of the prior art is that current methods that enable automatic adjustment of the print heads are extremely complex and have therefore not been adopted in practice due to high costs and functional deficiencies.Due to the state-of-the-art arrangements, manual adjustment is inefficient and requires a lot of time, which results in the system being down and thus indirectly causing costs.

[0005] The object of the present invention is therefore to overcome the disadvantages of the prior art, or at least to offer an alternative, and to provide an improved arrangement of print heads. This object is achieved by the arrangement and method according to the independent claims. Advantageous further developments can be found in the dependent claims. Thus, an improved arrangement of print heads and improved methods for adjusting the same are provided.

[0006] The present invention enables faster and easier assembly and adjustment of print heads, more precise positioning, and thus reduced downtime and improved print quality. Furthermore, standard components and parts can be used cost-effectively. The assembly also allows for high static rigidity with minimal overall dimensions and is resistant to thermal changes. The assembly can also be easily adapted to all common types of print heads and scaled to any size, including print widths of 2000 mm and more. The methods allow for simple and precise alignment of the heads relative to one another, as well as adjustment of the individual colors relative to one another if different print heads are to be used for different colors.The setup process can also be automated with minimal effort, allowing setup to be completed in minutes, saving hours or days compared to conventional solutions. Furthermore, no specially qualified employees are required.

[0007] In a first embodiment, an arrangement of print heads in a plane is provided, the arrangement comprising at least two linear guides connected at their ends via crossbeams. The linear guides act like rails. The arrangement further comprises a plurality of print heads arranged in one or more rows between the linear guides, and a plurality of connecting elements, each of which is arranged displaceably along one of the linear guides, and connection points to which up to two adjacent print heads of a row are detachably attached. At least one connecting element of a row has a detachable fixation with which the row is detachably fixed against displacement along the corresponding linear guide.

[0008] This arrangement allows the print heads in a row to be installed one after the other and then aligned. The removable fasteners in each row allow the print heads in a row to be aligned together along the linear guide to the other rows. Because two adjacent print heads can be attached or detachably attached to the connecting elements – except at the edge of each row – distance adjustments can also be made between individual print heads.

[0009] Optionally, each connecting element can include a ball carriage that can be moved without play on one of the linear guides.

[0010] This improves adjustment even further, as it makes moving along the linear guides easier.

[0011] Optionally, those connecting elements that have the detachable fixings can be arranged at the edge of the linear guides.

[0012] Although any of the fasteners could encompass the fixations, access to loosen and fasten the fixations at the edge might be easiest for one person.

[0013] Optionally, at least one detachable fixation of each row is a lockable adjustment option with which the corresponding row can be moved longitudinally along the linear guides.

[0014] In contrast to simple fixation, an adjustment option, e.g., a sliding mechanism, offers an integrated option for mechanically adjusting the longitudinal position, i.e., along the linear guide. This can facilitate adjustment.

[0015] Optionally, such an adjustment option is motor-driven. Because the adjustment option is motor-driven, the adjustment process can be controlled by the control system, allowing the system to move to calculated positions.

[0016] Optionally, print heads are arranged on both sides of central linear guides via connecting elements, and each print head is attached to one or two connecting elements on one side, and there are up to two rows of print heads between each two of the linear guides.

[0017] With this design, linear guides can be eliminated.

[0018] Alternatively, print heads are arranged on both sides of the middle linear guides via connecting elements, and each print head is attached to a connecting element on two opposite sides, and a row of print heads is located between each two of the linear guides.

[0019] This design increases stability and makes the assembly less susceptible to thermal deformation.

[0020] Optionally, the connection points are designed in such a way that the distance between the print heads attached to them can be adjusted.

[0021] The fact that the connection points offer the possibility of adjusting the distance further improves the arrangement, as the effort required to adjust individual print heads is simplified.

[0022] In one embodiment, the connection points optionally comprise a loose side and a fixed side, wherein the loose side in the released state allows mechanical play for adjustment.

[0023] This option for adjusting the distance simplifies the alignment of the print heads. Optionally, the print heads can be designed so that the connecting elements of adjacent print head rows are arranged offset on the linear guides.

[0024] By staggering the connecting elements, space can be saved and the arrangement can be made more compact.

[0025] Optionally, the connection points and / or the removable fixings include screws, pins, pneumatic or hydraulic clamps or electromagnets.

[0026] The print head mounting options listed above can meet a variety of requirements. Pins and screws can be used for manual adjustment. In environments where adjustment can be fully automated, pneumatic or hydraulic clamps or electromagnets can be used.

[0027] Optionally, the linear guides are mounted on supports that form a frame with the cross beams.

[0028] Such a frame also increases overall stability and can simplify replacement if the entire assembly needs to be replaced. A complete replacement may be necessary, for example, if the printing medium, e.g., the ink, is changed to change the color(s) or to print something else that requires different print heads, such as varnish.

[0029] In a further embodiment, a method for adjusting a row of printheads in an arrangement as described above is provided. The method comprises releasing the fasteners of the row that includes the printheads to be adjusted. The row is then moved, and the previously released fasteners are then re-secured.

[0030] With the arrangement described above, the entire row of printheads can be adjusted by loosening a single fastener. In a further embodiment, a method for adjusting printhead spacing in a row of an arrangement as described above is provided. The method comprises loosening an edge side of a row, loosening a connection point of a printhead in a row whose spacing is to be adjusted, adjusting a position of the printhead, fastening the previously loosened connection point, and loosening the fastener of the row. For connection points with both a fixed and a loose side, only the loose side is loosened, since the loose side allows the necessary play to adjust the spacing.

[0031] Due to the arrangement described above, a print head in a row can be easily adjusted using the described method.

[0032] Optionally, with both methods, the row or print head can be adjusted using an adjustment option at the non-fixed edge end of the row.

[0033] This utilizes the integrated option to mechanically adjust the longitudinal position, i.e., along the linear guide. This can simplify adjustment.

[0034] The embodiments show possible variants. The invention is not limited to the specifically illustrated variants; rather, combinations of the individual variants are also possible. In particular, the refinements of the device can also be used in the system or method presented.

[0035] For a better understanding of the invention, it is explained in more detail using the following figures.

[0036] They show in a highly simplified, schematic representation:

[0037] Fig. 1 shows an arrangement of print heads according to an embodiment in plan view;

[0038] Fig. 2 shows an arrangement of print heads according to an embodiment in side view;

[0039] Fig. 3 shows an exemplary fixation at the end of a linear guide according to one embodiment; Fig. 4 shows connection points of a connecting element according to one embodiment;

[0040] Fig. 5 Connection points of a connecting element with fixed and loose side according to a

[0041] embodiment;

[0042] Fig. 6 shows a design of a detachable fixation with adjustment possibility according to an embodiment, and

[0043] Fig. 7 shows an arrangement according to an embodiment with several linear guides in overview.

[0044] By way of introduction, it should be noted that in the variously described embodiments, identical parts are provided with identical reference symbols or component designations. The disclosures contained throughout the description can be applied analogously to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the directly described and illustrated figure, and these positional information must be applied analogously to the new position in the event of a change in position.

[0045] Fig. 1 shows an exemplary representation of an inventive arrangement 1 of print heads in a top view. Fig. 2 shows the same arrangement in a side view. The arrangement 1 comprises at least two linear guides 2, which are connected at their ends via cross members 5. The cross members 5 can be designed, for example, as end plates. Alternatively, the cross members 5 can also be simple upright profiles, which ideally have high flexural rigidity. The design of the upright profiles can be dimensioned and designed according to requirements.

[0046] The linear guides 2 can be screwed to the cross members 5, for example, but can also be attached in a different way, e.g. in a non-detachable manner, for example by welding.

[0047] For example, guides with a 9 mm width can be used as linear guides 2. A plurality of print heads 20 are mounted on the linear guides 2, arranged in one or more rows between the linear guides 2. The print heads 20 are attached to the linear guides 2 via a plurality of connecting elements 8, 9, 12. Each of the connecting elements 8, 9, 12 is arranged on one of the linear guides 2 such that the respective connecting element 8, 9, 12 can be moved along the linear guides 2.

[0048] The print heads 20 are thus mounted in a floating manner and a thermally induced expansion of the frame, i.e. the cross and possibly longitudinal beams, with the linear guides 2 has no influence on the distances between the print heads 20.

[0049] Each of the connecting elements 8, 9, 12 has connection points 11, 13, 14 to which one or two adjacent print heads of a row are detachably attached. The connection points 11, 13, 14 can be designed such that the distance between the print heads attached to them is adjustable.

[0050] Fig. 4 and Fig. 5 show exemplary connection points. Fig. 4 shows an example of a connecting element 8, 9, 12 with symmetrical connection points 11. Fig. 5 shows an example of a connecting element 8, 9, 12 with asymmetrical connection points, ie, a loose side 13 and a fixed side 14, wherein the loose side 13 allows mechanical play for adjustment in the released state.

[0051] At least one connecting element 12 of a row has a releasable fixing device 18, which releasably fixes the row against displacement along the corresponding linear guide 2. Fig. 3 shows such a fixing device. If this fixing device 18, or all fixing devices of a row, are released, the entire row can be moved longitudinally along the linear guide 2, allowing the print heads 20 located in this row to be adjusted.

[0052] On the linear guides 2 there are connecting elements 8, 9, 12 to which the print heads 20 are attached.

[0053] Advantageously, the connecting elements 12 with the fixings 18 can be attached to the edge so that they are easily accessible.

[0054] In order to facilitate the movement, ie shifting of the rows, the connecting elements 8, 9, 12 can each comprise a roller carriage 3 or ball carriage 4, via which the respective connecting element 8, 9, 12 can be shifted on the corresponding linear guide 2 without play.

[0055] Such roller carriages 3 or ball carriages 4 have compact dimensions and are available as prefabricated components in various accuracies.

[0056] The fixing means 18 or fixing means 18 of each row can also be designed as a lockable displacement mechanism or adjustment option 15, 16, with which the corresponding row can be displaced longitudinally along the linear guide 2. This means that each row is equipped, for example, with a rod 15, a spindle 15 or a pin 15 with an external thread that engages with an internal thread of a holder 16 that is connected to the linear guide 2 or to a cross member 5. A handle or similar device that rotates the rod 15, spindle 15 or pin 15 generates a feed, whereby the row of print heads 20, which are connected via the connecting elements 8, 9, 12, can be displaced along the linear guide 2 and thus adjusted. Depending on the fastening, the holder 16 can also be rotated while the pin 15, the spindle 15 or the rod 15 remains fixed.

[0057] The adjustment means 15, 16 can also be driven by a motor 17, which allows for further automation.

[0058] Different configurations can be provided for the arrangement. In a first example, each row is attached to a linear guide 2.

[0059] In a further example, print heads 20 are arranged on both sides of the middle, i.e. internal or not edge-arranged, linear guides 2 via connecting elements 8, 9, 12, each print head 20 being attached to a connecting element 8, 9, 12 on two opposite sides, so that a row of print heads 20 is located between each two of the linear guides 2.

[0060] Thus, a linear guide 2, e.g., a vertical profile, can accommodate the connecting elements 8, 9, 12—if necessary with ball carriages (4)—of the two head rows adjacent to the linear guide 2, whereby only three linear guides 2 are required for two head rows. Generally speaking, for this basic variant, one more linear guide 2 is required than print head rows. Fig. 1 shows the example with two print head rows and three linear guides 2, Fig. 7 shows an example with five print head rows and six linear guides 2.

[0061] Another example is an arrangement in which print heads 20 are arranged on both sides of the central linear guides 2, i.e. on the inside or not on the edge, via connecting elements 8, 9, 12 in such a way that each print head 20 is attached to one or two connecting elements 8, 9, 12 on only one side, and between each two of the linear guides 2 there are up to two rows of print heads 20.

[0062] Here, two rows of print heads 20 are located between each of the two linear guides 2, each of which is attached to the linear guides 2 on only one side – alternating, one row on one side, the next on the opposite side – via the connecting elements 8, 9, 12. Thus, for example, for four rows of print heads 20, only three linear guides are required, and for eight rows of print heads 20, only five linear guides 2 are required.

[0063] Optionally, the print heads 20 are designed so that the connecting elements 8, 9, 12 of adjacent print head rows can be arranged offset on the linear guides 2. This saves space and allows for a more compact arrangement. The offset mounting of the connecting elements 8, 9, 12 can be seen in Figures 1 and 7.

[0064] Both the connection points 11, 13, 14 and the removable fixings 18 can be designed in various ways. For example, as screws or pins, but also as pneumatic or hydraulic clamps or electromagnets. The design chosen depends on various factors, such as how often print heads are expected to be changed or how the adjustment is effected, for example, manually or automatically.

[0065] For connecting elements whose connection points 13, 14 are designed as a loose side 13 and a fixed side 14, a pin can be inserted, for example, for guidance on the respective loose side 13. This pin allows longitudinal movement in a guide, for example, a slotted hole. The fixed side 14 then has a pin for guidance and a screw for securing the print head 20.

[0066] Finally, the linear guides 2 can be mounted on supports that form a frame with the cross members 5. Since they run parallel to the linear guides, these can also be called longitudinal members. The outer supports, which run parallel to the linear guides 2, can also assume the function of a linear guide 2, i.e., these outer supports are essentially designed as linear guides, but reinforced to create a stable frame. Alternatively, linear guides 2 can be installed parallel and inwardly directly adjacent to the supports.

[0067] However, it is also possible for the rows and linear guides 2 to be constructed such that the print heads 20 on one or both sides of the arrangement 1 do not require a linear guide 2, i.e., the print heads 20, as described above, are attached to connecting elements 8, 9, 12 on only one side via connection points 11, 13, 14. This can be done symmetrically or asymmetrically, i.e., in both outer rows, or only in one of the outer rows.

[0068] In addition, fastening points for a cover plate 7 can be provided at various locations on the arrangement 1, advantageously in such a way that the movement of the rows and printing by the print heads 20 are not impaired. The cover plate 7 can be fastened to the cross members 5, the longitudinal members, the fastening points of the linear guides 2, or other suitable points. The fastening can be in addition to existing fastenings or to those already present. The fastening can be made, for example, at the fastening points of the linear guides 2 using specially manufactured screws 6 with a counter thread to which the cover plate 7 can be mounted. The fastening alternatives already mentioned above can also be considered here.

[0069] Recesses for the print heads 20 can be provided in the cover plate 7. Additional recesses can be positioned such that all elements necessary for mounting, adjusting (i.e., adjusting), and dismounting the print heads 20 are accessible without having to remove the cover plate 7. The cover plate 7 protects the print heads 20 from mechanical damage and prevents ink mist and dirt from penetrating the assembly, i.e., the print module.

[0070] The previously described arrangement 1 can be configured as follows. The print heads 20 of a row are connected by connecting elements 8, 9, 12. Each connecting element 8, 9, 12 can be mounted on a roller carriage 3 or ball carriage 4, which runs on a linear guide 2. The print heads 20 are thus mounted in a floating manner, and thermal expansion, i.e., thermal expansion of the frame (which can consist of cross and longitudinal beams, as described above) and the linear guides 2, has no influence on the spacing between the print heads 20.

[0071] The print heads 20 form rows, each of which is composed of print heads mounted on the same linear guides 2. Each of these head rows can be moved completely, i.e., all print heads 20 of a row together, along the respective linear guide 2. This can be achieved, for example, via a pin 15, a spindle 15, or a rod 15 provided on one side of the linear guide, or a comparable adjustment option 15, 16. This has also been described previously with various alternatives.

[0072] In summary, a row of print heads 20 in an array 1 is adjusted as follows. First, the fasteners 18 of the row or rows comprising the print heads 20 to be adjusted are loosened. Then, this row or these rows are moved. This can be done using the previously described adjustment option or the displacement mechanism 15, 16. Each of the rows is moved or shifted along the respective linear guide 2 to which the row is attached, so that the row is correctly positioned in the longitudinal direction. This can be determined by measurement or by means of a test print. Subsequently, the previously loosened fasteners 18 are reattached.

[0073] When using multiple rows of heads, the necessary longitudinal adjustment to each other is thus possible easily and precisely.

[0074] The distance between the print heads 20 in a row can be adjusted as follows. First, the row is fixed to a location on the linear guide 2 using the fixation 18. This may already be fixed, in which case this step can be omitted. Then, the print head 20 to be adjusted is loosened at its connection points 11, 13, 14 so that it can be moved relative to its neighboring print head 20, i.e., its distance from the neighboring print head 20 can be changed.

[0075] If the arrangement is designed in such a way that the connecting elements 8, 9, 12 have connection points 13, 14 in the form of a fixed side 14 and a loose side 13, only the fixed side 14 is released, because then the respective print head is already adjustable. Each connecting element 8, 9, 12 (except those at the edge) thus accommodates a print head 20 in a fixed position and one in the adjustable position. The adjustable position, i.e., the loose side 13, can be designed differently depending on the type and manufacturer of the print head 20. In Fig. 5, a centering hole is provided as the loose side 13, for example. In this case, the print head 20 can be positioned, for example, using pins via the centering hole. The loose side 13 allows a slight displacement along the longitudinal axis of the print head 20.

[0076] This allows a fine adjustment of the distance between the print head 20 and the adjacent print head 20.

[0077] The adjustment of a print head 20 is performed starting with the print head 20 that is fixed to the linear guide 2 via the fixing 18 of the connecting element 12. This means that this print head is adjusted first, if necessary after loosening the fixing 18. The fixing 18 is then reattached if necessary. If the distances are now adjusted on one or both sides of this fixed print head 20, this change in the distance affects all other print heads in the respective direction, because they are still firmly connected to one another and can be moved along the linear guide.

[0078] The various configurations of the fixation device 18 have already been described. These can include screws, pins, pneumatic or hydraulic clamps, or electromagnets. Other alternatives are also conceivable.

[0079] At the point in the row where the spacing needs to be adjusted, the fastening of the loose side 13 on the connecting element 8, 9, 12 is loosened. Since the remaining print heads 20 are still firmly connected, they can now be moved together using the adjustment mechanism 15, 16, which changes the spacing on the connecting element 8, 9, 12 with the loosened loose side 13. The spacing between the print heads 20 can be increased or decreased by the desired amount.

[0080] Then the fastening of the loose side 13 is refastened and the fixing 18 of the last print head 20 is released again, whereby the row is released.

[0081] Advantageously, the row is fixed at one end, and the spacing is adjusted at the other end, i.e., the fixation 18 and the adjustment mechanism 15, 16 are located at opposite ends of the row. In other words, moving the row or adjusting the position of the print head 20, or the print head 20 that is currently being adjusted, is performed via an adjustment mechanism at the non-fixed edge of the row.

[0082] In summary, the spacing between the print heads 20 in a row is adjusted as follows. First, one edge of a row is fixed. Subsequently, at least one connection point 11, 13, 14 of a print head in a row whose spacing is to be adjusted is released. Then, the spacing between the print heads is adjusted at the released connection point, i.e., the position of the print head 20 to be adjusted is adjusted. Subsequently, the released connection point 11, 13, 14 is reattached. At the end of the process, the fixed fixture 18 is released again.

[0083] However, before loosening the clamp, you can continue adjusting additional distances in the same row. If multiple distances need to be adjusted, the steps of loosening the connection points, adjusting the positions, and tightening the loosened connection point are repeated in sequence for each print head 20 to be adjusted. Only after all print heads 20 have been adjusted is the clamp 18 of the row finally loosened.

[0084] By means of the methods provided by the invention, the adjacent print heads 20, which may already be correctly spaced from the respective neighboring print head 20, are moved as a whole row during the adjustment process in the arrangement 1. This is an advantage over the prior art, since with the previously common, conventional mounting of print heads in a base plate, all adjacent heads generally have to be repositioned, which causes considerable additional effort.

[0085] In the event that print heads 20 need to be rotated relative to the printing plane, i.e., adjusted at an angle in the printing direction, this can also be achieved with the arrangement 1 according to the invention, since a rotation mechanism can be attached. This can be attached separately or as a unit with the adjustment means 15, 16. The angle can then be permanently set by securing the locking device. Both the locking device and the rotation can be configured to be pneumatic, hydraulic, electromagnetic, or otherwise remotely operable, analogous to the previously described fastenings and adjustment means 15.

[0086] A further advantage of the subject matter of the invention is that it enables or simplifies further automation. Since both the fixations 18 and the connection points 11, 13, 14 can be configured with pneumatic, hydraulic, electromagnetic, or similar remote-controlled locking devices, and the adjustment options 15, 16 can also be configured to be remotely controlled via a motor 17, human intervention on the arrangement 1 is no longer necessary and can be largely automated.

[0087] For this purpose, one or more cameras can be positioned underneath the heads and record the positions of the print heads or print nozzles. Alternatively, a test print can be performed, which is recorded by cameras and then evaluated.

[0088] The exact distances can be calculated from the image data captured by the camera or cameras. The positions to be corrected can then be calculated and transmitted to a person or a control and regulation unit.

[0089] As a semi-automated process, a person and a system can work together. If the system or a person check determines that a correction is necessary, the necessary offset can, for example, be precisely determined by the system. The system can fix the fixation. After the system prompts the person to start the adjustment and the person confirms, the system instructs the person which fasteners need to be loosened manually. After confirmation that the fasteners have been loosened manually, the system moves the corresponding print heads and / or rows by the exact offset that was determined. To make it easier to find the correct fasteners, corresponding markings can be made on the cover plate 7. The system then instructs the person to retighten the loosened fasteners.This can be repeated in the same row for each print head 20 that needs to be adjusted, if necessary.

[0090] The embodiments show possible embodiments, whereby it should be noted at this point that the invention is not limited to the specifically illustrated embodiments thereof, but rather various combinations of the individual embodiments with each other are also possible and this possibility of variation lies within the skill of the person skilled in this technical field due to the teaching of technical action by means of the objective invention.

[0091] The scope of protection is determined by the claims. However, the description and drawings must be used to interpret the claims. Individual features or combinations of features from the various embodiments shown and described may represent independent inventive solutions. The problem underlying these independent inventive solutions can be derived from the description.

[0092] All information on value ranges in this description is to be understood as including any and all sub-ranges thereof, e.g. the information 1 to 10 is to be understood as including all sub-ranges starting from the lower limit of 1 and the upper limit of 10, ie all sub-ranges begin with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

[0093] For the sake of clarity, it should be noted that some elements have been shown not to scale and / or enlarged and / or reduced in size to improve understanding of the structure.

[0094] Arrangement of print heads

[0095] Linear guides

[0096] Roller carriage

[0097] Ball carriage

[0098] Cross members, end plates

[0099] Fastening screws

[0100] Cover plate ,9 Connecting elements 1 Connection point with symmetrical sides 2 Connecting elements with fixation 3 Connection point, loose side 4 Connection point, fixed side 5 Pin, spindle or rod with external thread 6 Bracket with internal thread 7 Motor 8 Fixings 0 Print heads

Claims

Patent claims Arrangement (1) of print heads (20) in a plane, comprising: at least two linear guides (2) which are connected at their ends via cross members (5); a plurality of print heads (20) which are arranged in one or more rows between the linear guides (2); and a plurality of connecting elements (8, 9, 12), each of which is arranged displaceably on one of the linear guides (2) therealong and has connection points (11, 13, 14) to which up to two adjacent print heads (20) of a row are detachably attached; wherein at least one connecting element (12) of a row has a detachable fixing (18) with which the row is detachably fixed against displacement along the corresponding linear guide (2).Arrangement (1) according to one of the preceding claims, wherein each connecting element (8, 9, 12) comprises a roller carriage (3) or ball carriage (4) that can be moved without play on one of the linear guides (2). Arrangement (1) according to one of the preceding claims, wherein the connecting elements (12) that have the releasable fixings (18) are arranged at the edge of the linear guides. Arrangement (1) according to one of the preceding claims, wherein at least one releasable fixing (18) of each row is a lockable adjustment option (15, 16) with which the corresponding row can be moved longitudinally along the linear guides (2). Arrangement (1) according to claim 4, wherein the adjustment option (15, 16) is motor-driven (17). Arrangement (1) according to one of the preceding claims, wherein print heads (20) are arranged on both sides of the central linear guides (2) via connecting elements (8, 9, 12); and each print head (20) is attached to one side on one or two connecting elements (8, 9, 12), and up to two rows of print heads (20) are located between each two of the linear guides (2); or each print head (20) is attached to a connecting element (8, 9, 12) on two opposite sides, and a row of print heads (20) is located between each two of the linear guides (2). Arrangement (1) according to one of the preceding claims, wherein the connection points (11, 13, 14) are designed such that the distance between the print heads (20) attached thereto is adjustable.Arrangement (1) according to one of the preceding claims, wherein the connection points (13, 14) comprise a loose side (13) and a fixed side (13), wherein the loose side (13) allows mechanical play for adjustment in the released state. Arrangement (1) according to one of the preceding claims, wherein the print heads (20) are designed such that the connecting elements (8, 9, 12) of adjacent print head rows are arranged offset on the linear guides (2). Arrangement (1) according to one of the preceding claims, wherein the connection points (11, 13, 14) and / or the releasable fixings (18) comprise screws, pins, pneumatic or hydraulic clamps, or electromagnets. Arrangement (1) according to one of the preceding claims, wherein the linear guides (2) are mounted on supports (1) which form a frame with the cross members (5). A method of adjusting a row of printheads (20) in an array (1) according to any one of claims 1 to 11, the method comprising:. Releasing fixations (18) of the row comprising print heads (20) to be adjusted; moving the row; and Fixing the previously released fixings (18). A method for adjusting print head spacing in a row of an arrangement (1) according to one of claims 4 to 11, the method comprising: Fixing the fixation (18) of an edge side of a row; Detaching at least one connection point (11, 13, 14) of a print head (20) of a row whose spacing is to be adjusted; Adjusting a position of the print head (20) via the adjustment option (15, 16); securing the previously released connection point; and Releasing the fixation (18) of the row. The method according to claim 13, wherein the release of at least one connection point (11, 13, 14) of a print head (20) is effected by releasing a fixed side (14) of a print head (20) while the loose side (13) remains. The method according to one of claims 12 to 14, wherein the movement of the row or the adjustment of the position of the print head (20) is performed via an adjustment option at the non-fixed edge end of the row.

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