Device for adjusting a print head

Abstract

The present invention relates to a device for adjusting a print head, comprising a step switching mechanism (21) and an actuator (22) for switching the step switching mechanism (21) and a rotatably supported stop disk (30), characterized in that there is a first switching tongue (31a) for rotating the stop disk (30) stepwise in a first rotational direction (54a), the first switching tongue having two elongated holes (33, 34) for guiding the first switching tongue, one of the elongated holes having a side clearance (35). The present invention enables precise adjustment of the print head and keeps time and costs very low. The present invention is preferably used in industrial inkjet printing.

Description

Technical Field

[0001] The present invention relates to a device for adjusting a print head.

[0002] The present invention belongs to the technical field of the graphic industry, especially for industrial inkjet printing on a flat substrate, i.e., a printing medium in the form of a single sheet, a web, a film, or a label (preferably made of paper, cardboard, paperboard, plastic, metal, or composite material), i.e., high-volume inkjet printing (inkjet printing), i.e., applying fine liquid ink droplets according to an image. The application of the ink is carried out by an inkjet print head. In order to obtain a high-quality printing effect, the position and orientation between the inkjet print heads must be adjusted. Background Art

[0003] DE102016209945A1 discloses a device for adjusting a print head. The device includes a stepper switching mechanism for each print head and a movable slider for operating the stepper switching mechanism, and the slider can be positioned opposite each print head to be adjusted.

[0004] DE102017215314A1 discloses a similar device for adjusting a print head and such a printing unit. The device includes a stepper switching mechanism for each print head and an actuator arranged on the movable slider for operating the stepper switching mechanism. The actuator can be positioned opposite each print head to be adjusted by the slider and is operated, for example, pneumatically. The corresponding stepper switching mechanism includes a threaded spindle with a cone, and during the switching process, the threaded spindle rotates step by step through a gear.

[0005] EP3530473A1 discloses another device for adjusting a print head. The device includes two stepper switching mechanisms for each print head to be adjusted, and one stepper switching mechanism is for adjusting each degree of freedom (rotation, translation).

[0006] WO2017 / 011924A1 also discloses another device for adjusting a print head.

[0007] In contrast, EP3527390B1 discloses a tool-free operable device for adjusting a print head, which includes a cone and a head with a stop device.

[0008] WO2014 / 160219A1 discloses an adjustable bracket for a print head. The bracket can be clamped by two clamps with a lever and a sliding wedge.

[0009] Precisely adjusting a large number of print heads with the same number of adjustment components and drive devices is time-consuming, and depending on the different adjustment components and drive devices provided, the cost is also high. Summary of the Invention

[0010] Therefore, the object of the present invention is to improve the prior art, in particular to enable precise adjustment of the print head while minimizing time and cost.

[0011] This object is solved by an inkjet printing press according to a preferred embodiment of the present invention.

[0012] The advantages of the present invention and thus preferred expansion solutions are derived from alternative embodiments, the description and the drawings.

[0013] The present invention relates to a device for adjusting a print head, comprising a step switching mechanism and an actuator for switching the step switching mechanism, as well as a rotatably supported stop disk, characterized in that there is a first switching tongue for rotating the stop disk stepwise in a first rotational direction, the first switching tongue having two elongated holes for guiding the first switching tongue, one of the elongated holes having a side clearance.

[0014] Advantageous design and effects of the present invention

[0015] The present invention advantageously enables precise adjustment of the print head while keeping time and cost low.

[0016] According to the present invention, two elongated holes are provided, one of the elongated holes having a side clearance, thereby providing a simple technical solution for the step switching mechanism to adjust the print head by using a movable and actuator-operable switching tongue.

[0017] Expansion solutions of the present invention

[0018] The following describes the preferred expansion solutions of the present invention (abbreviation: expansion solutions).

[0019] One expansion solution is characterized in that there is a second switching tongue for rotating the stop disk stepwise in a second rotational direction opposite to the first rotational direction, the second switching tongue having two elongated holes for guiding the second switching tongue, one of the elongated holes having a side clearance.

[0020] One expansion solution is characterized in that two elongated holes with side clearances are used for the lateral compensation movement of each switching tongue. One expansion solution is characterized in that the two elongated holes with side clearances are implemented to be mirror images of each other.

[0021] One expansion solution is characterized in that the first switching tongue or the second switching tongue each performs a forward movement and an opposite return movement as the switching movement.

[0022] One expansion solution is characterized in that the first switching tongue or the second switching tongue switches the stop disk in a form-fitting manner during the switching movement. One expansion solution is characterized in that the first switching tongue or the second switching tongue scrapes the stop disk in a friction-fitting manner during the return movement.

[0023] One expansion solution is characterized in that a lock or a brake is provided for the stop disk, and the lock or the brake can prevent the stop disk from moving uncontrollably and / or moving during the return movement of the switching tongue. The brake can be designed as a disk spring under the stop disk.

[0024] One expansion solution is characterized in that a spring element is provided for each switching tongue, and the spring element moves the unactuated switching tongue away from the stop disk.

[0025] One expansion solution is characterized in that a transmission device is provided, and the transmission device converts the adjustment movement of the stop disk into a correction movement of the print head.

[0026] The features and feature combinations disclosed in the above technical field, invention content, and expansion solution paragraphs, as well as the following embodiment paragraphs, form other advantageous expansion solutions of the present invention in any combination with each other. Brief Description of the Drawings

[0027] Figures 1 to 7 The preferred embodiments and expansion solutions of the present invention are shown. Corresponding features are denoted by the same reference numerals in the drawings. For the sake of clarity, some of the repeated reference numerals in the figures are omitted. Detailed Description of the Invention

[0028] Figure 1 A perspective view of a preferred embodiment of a printing beam of a printing unit according to the present invention (for example, the printing unit 3 of the inkjet printer 1; see Figure 7 ) is shown. The preferably position-fixed printing beam 4 includes a cross beam 4a. A plurality of adjacent print heads 5 or a row arrangement 7 composed of a row of adjacent print heads 5 are arranged on the cross beam, and each print head is arranged on its respective print head support 8 in a guiding device 9 and has a nozzle surface 5a (for example, also see Figure 2 ). The print heads 5 are preferably supplied with ink in a circulating manner, for example, through the pipeline 6 in the figure. The inkjet printer 1 further includes a computer 12, preferably a digital computer, for controlling the adjustment process.

[0029] In Figure 1 , an adjustment device 20 can also be seen, and the adjustment device is used to adjust or calibrate each print head 5. The adjustment device 20 includes a plurality of step switching mechanisms 21 adjacent to each other or arranged in rows, and each step switching mechanism has a first step switching mechanism 21a and a second step switching mechanism 21b. These step switching mechanisms are shown in detail and described in more detail in Figures 2 to 6 .

[0030] Give Figure 1 The printing beam 4 shown in FIG. 1 (like other printing beams) is provided with a cleaning device 10 which can be moved back and forth in the direction 53 for cleaning the printing head on the printing beam 4 which is preferably arranged in a fixed position. During printing, the cleaning device 10 is in a parked position ( Figure 1 ), while during the cleaning mode, the cleaning device 10 is in the cleaning position ( Figure 1 ). Figure 1 In the illustration of , the cleaning device 10 is currently in an intermediate position. Cleaning itself is not part of the invention. At least one co-movable actuator 22, preferably a pneumatically operable actuator, is arranged on the movable cleaning device 10. A drive motor 11 is provided to move the cleaning device 10 (see Figure 7 ).

[0031] Figure 2 A perspective view of a preferred embodiment of two step-by-step switching mechanisms is shown: a first step-by-step switching mechanism 21a and a second step-by-step switching mechanism 21b. Each of the two step-by-step switching mechanisms includes a stop disk 30 that can be rotated in a step-by-step manner. In addition, each of the two step-by-step switching mechanisms also includes two preferably vertically movable and individually operable switching tongues 31: a first switching tongue 31a, a second switching tongue 31b, a third switching tongue 31c and a fourth switching tongue 31d. The step-by-step switching mechanism 31 is equipped with a transmission device 40a and 40b having, for example, a gear 41 and / or a conical spindle 42, which converts the respective switching movement into a correction movement of the print head.

[0032] Each switching tongue 31 preferably comprises a projection 32 (see Figure 5 ), which interacts with the stop disk 30 or its stop device during the switching process. In addition, each switching tongue 31 also includes a first elongated hole 33 and a second elongated hole 34, wherein the first elongated hole 33 (such as the upper elongated hole) has a side recess 35. At the same time, these two elongated holes allow and limit the movement when cooperating with the pin 36. In the non-operated state, each switching tongue 31 is preferably in a lower position, into which they are pressed by their respective spring elements 37. In the operated state, each switching tongue 31 is preferably in an upper position, wherein the stop disk 30 is further rotated around the stop device. The pressure piece 38 can prevent the stop disk 30 from rotating unintentionally; alternatively, for example, a spring plate can also be used.

[0033] Figure 3 The side view of two step switching mechanisms and the same preferred embodiment in a non-operating state are shown, Figure 4 The side view of two step-by-step switching mechanisms and the same preferred embodiment in the operating state are shown. Figure 3 andFigure 4 It can be seen that the two actuated switching tongues 31a and 31c move upward or are in the upper position, while the two unactuated switching tongues 31b and 31d are in the lower position.

[0034] Figure 5 Side view showing a preferred embodiment of the switching tongue. The actuator 22 enters the actuating position by a change in the position of the cleaning device 10, i.e., it is in a position opposite to the switching tongue 31, and is then preferably driven by the computer 12 and then performs a movement in the direction 55. Here, the actuator contacts the corresponding switching tongue 31, for example 31a, and displaces it according to the configuration of the first slot 33 and the second slot 34. The switching tongue 31 accordingly performs a movement in the direction 56: either a forward movement 58 (as a switching movement; an upward movement in the example shown), or a return movement 59 (a downward movement in the example shown). The side clearance 35 allows the switching tongue to perform a lateral compensation movement 57 during the switching movement. When switching using the switching tongue 31a, the stop disk 30 preferably rotates in the first rotational direction 54a via the lug 32; conversely, when switching using the switching tongue 31b, the stop disk 30 preferably rotates in the opposite second rotational direction 54b via the lug 32.

[0035] Figure 6 Cross-sectional view showing a preferred embodiment of the transmission. The conical main shaft 42 can be seen, which converts the rotational movement mediated by the stop disk 30 (and possibly intermediate gears) into a correction movement of each print head 5 or its print head holder 8. For this purpose, as Figure 6 shown, the conical main shaft performs a vertical movement by rotation, and this vertical movement is converted into a horizontal movement of the print head / print head holder via the respective cones.

[0036] Figure 7 Detail showing a preferred embodiment of an inkjet printer 1 for printing on a substrate 2 (e.g., a web). The inkjet printer 1 preferably includes a plurality of printing units 3 for multicolor printing. Each printing unit 3 includes a printing beam 4 (only one is shown exemplarily), which is aligned in the transverse direction 52a with the transport direction 51 of the substrate and has a print head 5. The drive motor 11 moves at least one cleaning device 10 (preferably all cleaning devices together, e.g., via a common frame) horizontally along the printing beam 4 in the movement direction 53. Here, the actuator 22 is successively located opposite each step switching mechanism 21 and can, if necessary, actuate the step switching mechanism, i.e., switch the step switching mechanism one or more times according to the correction requirements and the degree of correction. The correction movement of the print head 5 in its position and / or orientation accordingly takes place incrementally / stepwise (preferably in micron steps) in the transverse direction 52a and / or at an angle 52b to the transport direction 51.

[0037] List of reference numerals

[0038] 1 Inkjet printer

[0039] 2 Substrate

[0040] 3 Printing unit

[0041] 4 Printing beam

[0042] 4a Cross beam

[0043] 5 One print head / Multiple print heads

[0044] 5a Nozzle surface

[0045] 6 One pipeline / Multiple pipelines

[0046] 7 Row arrangement

[0047] 8 Print head support

[0048] 9 Guide device

[0049] 10 Cleaning device

[0050] 11 Driving motor

[0051] 12 Computer

[0052] 20 Adjusting device

[0053] 21 One step switching mechanism / Multiple step switching mechanisms

[0054] 21a First step switching mechanism

[0055] 21b Second step switching mechanism

[0056] 22 One actuator / Multiple actuators

[0057] 30 Stop disk

[0058] 31 One switching tongue / Multiple switching tongues

[0059] 31a First switching tongue

[0060] 31b Second switching tongue

[0061] 31c Third switching tongue

[0062] 31d Fourth switching tongue

[0063] 32 Bump

[0064] 33 First elongated hole

[0065] 34 Second elongated hole

[0066] 35 sided empty space

[0067] 36 one pin / multiple pins

[0068] 37 spring element

[0069] 38 lock or brake, especially pressure part

[0070] 40a transmission

[0071] 40b transmission

[0072] 41 one gear / multiple gears

[0073] 42 one tapered spindle / multiple tapered spindles

[0074] 51 conveying direction of the printing substrate

[0075] 52a transverse direction

[0076] 52b angle

[0077] 53 movement direction of the cleaning device

[0078] 54a first rotation direction of the stop disk

[0079] 54b second rotation direction of the stop disk

[0080] 55 movement direction of the actuator

[0081] 56 movement direction of the switching tongue

[0082] 57 lateral compensation movement

[0083] 58 forward movement / switching movement

[0084] 59 return movement.

Claims

1. A device for adjusting a print head, comprising a step switching mechanism (21), an actuator (22) for switching the step switching mechanism (21), and a rotatably supported stop disk (30). Characterized in that there is a first switching tongue (31a) for causing the stop disk (30) to rotate stepwise in a first rotation direction (54a), the first switching tongue having two elongated holes (33, 34) for guiding the first switching tongue, one of the elongated holes having a side clearance (35).

2. The device according to claim 1, characterized in that there is a second switching tongue (31b) for causing the stop disk (30) to rotate stepwise in a second rotation direction (54b) opposite to the first rotation direction (54a), the second switching tongue having two elongated holes (33, 34) for guiding the second switching tongue, one of the elongated holes having a side clearance (35).

3. The device according to claim 2, characterized in that the two elongated holes (33, 34) with side clearances (35) are for the lateral compensation movement (57) of the respective first or second switching tongue.

4. The device according to claim 2 or 3, characterized in that the two elongated holes (33, 34) with side clearances (35) are implemented to be mirror images of each other.

5. The device according to claim 2 or 3, characterized in that the first switching tongue (31a) or the second switching tongue (31b) each performs a forward movement (58) as a switching movement and an opposite return movement (59).

6. The device according to claim 2 or 3, characterized in that the first switching tongue (31a) or the second switching tongue (31b) form - fitly switches the stop disk (30) during the switching movement (58).

7. The device according to claim 6, characterized in that the first switching tongue (31a) or the second switching tongue (31b) frictionally scrapes the stop disk (30) during the return movement (59).

8. The device according to any one of claims 1 to 3, characterized in that a lock or a brake is arranged for the stop disk (30), which prevents the stop disk (30) from being adjusted uncontrollably and / or from being adjusted during the return movement (59) of the respective first or second switching tongue.

9. The device according to any one of claims 1 to 3, characterized in that a spring element (37) is arranged for each switching tongue, which spring element moves the unactuated switching tongue away from the stop disk (30).

10. The device according to any one of claims 1 to 3, characterized in that a transmission device (40a, 40b) is provided, which converts the adjustment movement (58) of the stop disk (30) into a correction movement of the print head.

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