Apparatus for powdering a printed sheet in a printing press

Abstract

The invention relates to a device for powdering a printed sheet (1) in a printing press, comprising a beam (2) having a row of nozzles, which row of nozzles has outer nozzles (3), inner nozzles (4) and nozzles (5) arranged between the inner nozzles and the outer nozzles. The nozzles (5) arranged between the inner nozzles and the outer nozzles are swingably mounted and there is at least one actuator (7) for swinging the nozzles (5) arranged between the inner nozzles and the outer nozzles relative to the outer nozzles (3) and the inner nozzles (4).

Description

Technical Field

[0001] The present invention relates to an apparatus for applying powder to printed sheets in a printing press, comprising a crossbeam having a nozzle row having an outer nozzle, an inner nozzle and a nozzle disposed between the outer nozzle and the inner nozzle. Background Technology

[0002] DE 10 2005 039 078 B3 describes a device for spreading sheets, in which the spray nozzles on the spray bar are angled at different angles. Here, the inner spray nozzle is tilted outwards and the outer spray nozzle is tilted inwards. Thus, the inner and outer spray nozzles are directed towards the edge region of the sheet. The spray nozzles are not supported in a swinging manner, but are assembled in their respective tilted positions, therefore the device cannot be altered in its specifications.

[0003] DE 10 2018 219 655 B3 describes a device for powdering printed sheets in a printing press. This device includes a jetting bar with a nozzle array having internal and external nozzles. A shut-off valve is configured for the external nozzles, allowing the jetting bar to be set to different powdering widths in a stepped manner. Disadvantageously, the switching stages are coarse, so that in unfavorable sheet sizes, the outermost nozzles of the activated nozzles spray beyond the page edges, thus contaminating the machine, and in other unfavorable sheet sizes, they fail to reach the page edges and do not completely powder the sheet. Summary of the Invention

[0004] The objective of this invention is to provide a powder-spraying device with variable specifications, which enables even unfavorable intermediate-sized printed sheets to be powdered thoroughly with minimal powder loss.

[0005] The task is solved by a device in a printing press for sprinkling powder onto printed sheets, the device comprising a beam having a nozzle row having an outer nozzle, an inner nozzle and a nozzle disposed between the inner nozzle and the outer nozzle, characterized in that the nozzle disposed between the inner nozzle and the outer nozzle is oscillatingly supported; and at least one actuator is provided for oscillating the nozzle disposed between the inner nozzle and the outer nozzle relative to the outer nozzle and the inner nozzle.

[0006] Various further solutions are possible.

[0007] The nozzle arranged between the inner nozzle and the outer nozzle is capable of swinging into an inclined position, in which the nozzle arranged between the inner nozzle and the outer nozzle is oriented at an acute angle relative to the inner nozzle.

[0008] The acute angles can be of the same size or of different sizes.

[0009] The nozzle arranged between the inner and outer nozzles can point outwards about the nozzle array in the tilted posture.

[0010] The nozzles arranged between the inner and outer nozzles can be seated in nozzle receptacles, which are hinged or rubber-elastic. Attached Figure Description

[0011] Further solutions are derived from the following description of the embodiments and the accompanying drawings, in which:

[0012] Figure 1 The powder-spreading equipment is shown.

[0013] Figure 2 A top view of the powder-spreading equipment is shown;

[0014] Figure 3 and 4 The image shows the oscillating nozzles of the powder-spreading device in different orientations. Detailed Implementation

[0015] Figure 1 The diagram shows a device for applying powder to sheet 1 in a printing press, a so-called powder bar. Sheet 1 is positioned relative to... Figure 1 The drawing plane passes through a crossbeam 2 with a row of nozzles 3, 4, and 5 in an orthogonal direction. These nozzles 3, 4, and 5 are connected to a piping system from which an air-powder mixture can be supplied to these nozzles. Only the left half of the crossbeam 2 is shown; the right half is constructed in mirror image. A set of outer nozzles 3, a set of inner nozzles 4, and a set of nozzles 5 located between the above sets and capable of swinging relative to the crossbeam 2 belong to the nozzles of the shown half of the crossbeam 2.

[0016] The printing press can handle sheets 1 with different specifications from printing job to printing job. When the size of sheet 1 is smaller than a predetermined boundary specification GF, it is preferably located between the outer nozzle 3 and the oscillating nozzle 5, and the outer nozzle 3 is deactivated, for example by means of a shut-off valve 6. If the actual size TF of sheet 1 is only slightly larger than the boundary specification GF, the outer nozzle 3 is not deactivated. Instead, the oscillating nozzle 5 oscillates outward to... Figure 1 In the tilted posture shown, the inner nozzle 4 is not wobbled and remains in a posture with a jet direction orthogonal to the printing sheet 1, as can be seen by means of the jet cone 11.

[0017] The oscillation of the oscillating nozzles 5 is achieved by at least one actuator 7. These oscillating nozzles 5 are preferably infinitely adjustable according to the corresponding specifications of the printed sheet. These oscillating nozzles 5 can be coupled to the actuator 7, for example, via one or more transmission devices, such that the angles α, β, γ of their tilting posture increase towards the outer nozzle 3 (α > β > γ), or are coupled such that the angles α, β, γ are equal in magnitude. The actuator 7 can be an electric motor.

[0018] The transmission device can be a screw drive. Here, different angles α, β, γ can be caused by sections of the screw with different thread pitches, where one turn of the common screw is converted into different sizes of oscillating motion of the nozzle 4.

[0019] If the oscillating nozzle 5 oscillates into an inclined position, the ejection cone 11 of the oscillating nozzle 5 closest to the outer nozzle 3 reaches the side edge of the actual specification TF, thereby also sprinkling powder on the sheet 1 in the area of ​​that edge. In the given example, the actual specification TF is about 10% wider than the boundary specification GF. Here, on both sides of the printing press (drive side, operating side), the ejection cone 11 closest to the side edge of the sheet 1 is ejected by the oscillating nozzle 5, which is inclined outward with respect to the nozzle row.

[0020] Figure 2 by Figure 1 View II given in the figure shows the section of the crossbeam 2 with the oscillating nozzle 5. It is shown that the oscillating nozzle 5 is formed via a nozzle tube 8, which is supported in the crossbeam 2 by a nozzle housing 9. The nozzle housing 9 is essentially in the shape of a ring or bushing. The nozzle tube 8 is inserted into the nozzle housing 9, which can be formed by a hinged eyelet or—as shown—by a rubber-elastic cup.

[0021] exist Figure 3 and 4 The section of the crossbeam 2 with the swingable nozzle 5 is shown in cross-sectional view, and the cross-sectional view is shown in cross-sectional view. Figure 1 The view shown is the same. Also shown is the hose 10 inserted into the nozzle tube 8, which belongs to the previously mentioned piping system through which the air-powder mixture is supplied to nozzles 3, 4, and 5. The actuator 7 acts on the nozzle tube 8.

[0022] It should be noted that there may be one actuator 7 for each oscillating nozzle 5 or a common actuator 7 for all oscillating nozzles 5. It is also possible that there is a first actuator 7 to oscillate a group of oscillating nozzles 5 closer to one end of the crossbeam 2 and a second actuator 7 to oscillate a group of oscillating nozzles 5 (not shown in the figure) closer to the other end of the crossbeam 2.

[0023] exist Figure 3In the middle, the swingable nozzle 5 does not deflect (α = 0°). When the actual specification TF is less than or equal to the boundary specification GF, this orthogonal orientation of the jet direction relative to the sheet surface is adopted.

[0024] exist Figure 4 In the middle, the oscillable nozzle 5 oscillates outward to an inclined position under the elastic deformation of the nozzle receiving part 9, relative to the vertical and the spray direction of the inner nozzle 4 (see...). Figure 1 The angle is α.

[0025] Reference number table

[0026] 1 sheet of printing

[0027] 2. Crossbeam

[0028] 3 External nozzle

[0029] 4. Internal nozzle

[0030] 5. Oscillable nozzle

[0031] 6. Shut-off valve

[0032] 7 Actuator

[0033] 8 Nozzle tube

[0034] 9. Nozzle Receiving Section

[0035] 10 Hose

[0036] 11. Jet Cone

[0037] GF boundary specifications

[0038] TF Actual Specifications

[0039] α, β, γ Angles.

Claims

1. An apparatus for applying powder to a sheet (1) in a printing press, comprising a crossbeam (2) having a nozzle row having an outer nozzle (3), an inner nozzle (4), and a nozzle disposed between the inner nozzle and the outer nozzle. Its features are, The nozzle arranged between the inner nozzle and the outer nozzle is pivotally supported and thus constructed as a pivotable nozzle (5), which is capable of pivoting into an inclined position in which the pivotable nozzle (5) points outward with respect to the nozzle row. There is at least one actuator (7) for oscillating the oscillable nozzle (5) relative to the outer nozzle (3) and the inner nozzle (4); and The device is configured such that when the size of the sheet (1) is smaller than a predetermined boundary size (GF), the outer nozzle (3) is deactivated, wherein the boundary size is between the outer nozzle (3) and the swingable nozzle (5); and if the size of the sheet (1) is slightly larger than the boundary size (GF), the swingable nozzle (5) swings outward into an inclined position, wherein the inner nozzle (4) is not swingable, and in the inclined position, the jet cone (11) of the swingable nozzle (5) closest to the outer nozzle (3) reaches the side edge of the size of the sheet.

2. The device according to claim 1, Its features are, The swingable nozzle (5) is oriented at an acute angle (α, β, γ) relative to the inner nozzle (4) in the tilted posture.

3. The device according to claim 2, Its features are, The acute angles (α, β, γ) are all the same size.

4. The device according to claim 2, Its features are, The acute angles (α, β, γ) are different in size from each other.

5. The device according to any one of claims 1 to 4, Its features are, The oscillable nozzle (5) is seated in the nozzle housing (9), which is hinged or rubber-elastic.

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