Sheet guiding device

Abstract

The present invention relates to an apparatus for guiding a sheet (3) during inspection in a printing press by means of a sheet inspection system, wherein the sidewalls (17, 18) of the housing (5) of the apparatus overlap with the sidewalls (19, 20) of the roller (1) that conveys the sheet (3), and the housing has an overpressure chamber (8).

Description

Technical Field

[0001] This invention relates to a device for guiding sheets during inspection in a printing press using a sheet inspection system. Background Technology

[0002] Such devices are described in DE 20 2006 011 273 U1 and DE 20 2007 009 389 U1.

[0003] DE 195 46 046 A1 describes a sheet guide roller with an air chamber extending from upstream to downstream, the air chamber being essentially defined by the two rollers, a rotating drum, an air conduction element, and lateral walls. Lateral sealing is achieved by the air conduction element protruding as closely as possible from the sidewalls. Summary of the Invention

[0004] The objective of this invention is to provide another type of device as mentioned at the outset.

[0005] This task is solved by a device for guiding sheets during inspection in a printing press using a sheet inspection system, characterized in that the sidewall of the housing having an overpressure chamber overlaps / laps with the sidewall of the conveying roller.

[0006] The advantage of this invention is that only a small amount of air can escape from the housing between these sidewalls and sides. This overlap creates a seal. Attached Figure Description

[0007] The extended scheme is described in the following embodiments and accompanying drawings, which show:

[0008] Figure 1 According to the device of the present invention, the page inspection system is arranged outside the housing of the page guiding device;

[0009] Figure 2 According to the device of the present invention, the page inspection system is arranged inside the housing of the page guiding device;

[0010] Figure 3 : A sectional view of the page guide device when adjusted to a larger size; and

[0011] Figure 4 : A cross-sectional view of the page guide device when it is set to the smallest size. Detailed Implementation

[0012] Figure 1A pressure roller 1 is shown, which, together with a rubber roller 2, forms a printing gap through which offset printing takes place. A sheet 3 is conveyed on the pressure roller 1 and held in place thereby by its clamping bridge 4.

[0013] A pneumatic sheet guide is arranged downstream of the printing gap. This pneumatic sheet guide presses the sheet 3 onto the pressure roller 1 and prevents vibration. The pneumatic sheet guide has a housing 5 that opens toward the pressure roller 1, thus forming a protective cover.

[0014] A page inspection system is arranged outside the housing 5. The page inspection system detects the optical properties of the printed image on the page 3. The page inspection system includes a camera 6 facing the page 3 and an illumination unit 7.

[0015] The pneumatic sheet guiding device is used to: place sheet 3 flat on the pressure roller 1 when sheet 3 is measured by the sheet inspection system. The camera 6's shooting line of sight is downstream of the housing 5 in the sheet conveying direction.

[0016] The housing 5 contains an overpressure chamber 8, which faces the counterpressure roller 1 and has no nozzle or air jet opening, but only a single opening with a width consistent with the sheet size. The overpressure filling the overpressure chamber 8 is symbolically represented by a double arrow and acts as an air cushion through the mentioned opening onto the sheet 3.

[0017] Figure 2 A modified embodiment is shown in which the housing 5 is enlarged such that the page inspection system can be arranged within the overpressure chamber 8. Apart from this, the system with the camera 6 and illumination unit 7 integrated is no different from the previously described system with external arrangement.

[0018] Next based on Figure 3 and Figure 4 The description of the internal structure of housing 5 also applies to Figure 1 and Figure 2 The two systems in. Figure 3 and Figure 4 The viewpoint on which it is based Figure 1 and Figure 2 The direction of the image plane.

[0019] The housing 5 includes a main pipe 9 attached to a blower 10, which generates overpressure in the overpressure chamber 8. External supply channels 11 and 12 and at least one internal supply channel 13 branch off from the main pipe 9, and these supply channels together form an arrangement parallel to the counterpressure roller 1.

[0020] Sliding walls 14 and 15 are arranged in the housing 5, and these sliding walls 14 and 15 can be adjusted to a larger interval according to the width of the page 3. Figure 3 ) and smaller intervals ( Figure 4 These sliding walls 14 and 15 limit the lateral extension of the overpressure chamber 8 located therebetween, thus making its specifications variable. The adjustment of these sliding walls 14 and 15 can be performed steplessly.

[0021] These external supply channels 11 and 12 are connected to the main pipeline 9 via shut-off valves 16 in the form of valves. The internal supply channel 13 is not equipped with such shut-off valves.

[0022] Figure 3 One configuration is shown in which the external supply channels 11, 12 also extend into the overpressure chamber 8 between the sidewalls 14, 15, and the shut-off valves 16 are open.

[0023] Figure 4 Another configuration is shown in which the sidewalls 14, 15 are adjusted toward each other to such an extent that the external supply channels 11, 12 lead to the outside of the overpressure chamber 8. In this configuration, the shut-off valves 16 are closed, and the overpressure chamber 8 is supplied with pressurized air only through the internal supply channel 13.

[0024] These shut-off valves 16 prevent air waste and reduce air consumption.

[0025] The housing 5 has side walls 17 and 18 that overlap with the sides 19 and 20 of the counterpressure roller 1, respectively. In the region of the overlap 21, there is only a narrow movement gap between these side walls 17 and 18 and the sides 19 or 20, allowing only a very small amount of excess air 22 to escape from the housing 5. The overlap 21 constitutes a seal, which significantly improves the effectiveness of the pneumatic flap guiding device. The excess air 22 originates from the overpressure chamber 8, which is laterally sealed relative to the surrounding environment in the first stage (Stufe) through these side walls 14 and 15 and in the second stage through the overlap 21.

[0026] Instead of the pressure roller 1 of the offset printing mechanism, the pressure roller of the glossing mechanism or the sheet conveying roller located between the two printing mechanisms can also be used as the inspection roller, which conveys the sheet 3 during the inspection period.

[0027] List of reference numerals

[0028] 1. Pressure roller

[0029] 2. Rubber roller

[0030] 3 pages

[0031] 4. Clamping Bridge

[0032] 5. Housing

[0033] 6 cameras

[0034] 7 Lighting Department

[0035] 8 Overpressure chamber

[0036] 9. Main pipeline

[0037] 10 Fans

[0038] 11 Supply Channels

[0039] 12 Supply Channels

[0040] 13 Supply Channels

[0041] 14 Sliding wall

[0042] 15 Sliding Wall

[0043] 16. Shut-off valve

[0044] 17 Sidewalls

[0045] 18 Sidewalls

[0046] 19 Side View

[0047] 20 Side View

[0048] 21. Overlap section

[0049] 22. Excess air (Falschluft)

Claims

1. A printing press, comprising a sheet inspection system and equipment for guiding sheets (3) during inspection using the sheet inspection system. Its features are, The sidewalls (17, 18) of the housing (5) of the device having an overpressure chamber (8) overlap with the sidewalls (19, 20) of the roller (1) that conveys the sheets (3) to limit excess air (22) originating from the overpressure chamber (8) from escaping from the housing (5).

2. The printing press according to claim 1, Its features are, A sliding wall (14, 15) is supported in the housing (5), which laterally limits the overpressure chamber (8).

3. The printing press according to claim 1 or 2, Its features are, Supply channels (11, 12, 13) branching off from the main pipeline (9) are arranged in the housing (5).

4. The printing press according to claim 3, Its features are, The supply channels (11, 12, 13) include external supply channels (11, 12), which are equipped with shut-off valves (16). An internal supply channel (13) is provided between the external supply channels (11, 12).

5. The printing press according to claim 1 or 2, Its features are, The sheet inspection system is arranged in the overpressure chamber (8).

6. The printing press according to claim 1 or 2, Its features are, The page inspection system is arranged outside the housing (5).

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