Apparatus for register control and a method for regulating such apparatus

Abstract

An apparatus for conveying a sheet-formed item from a digital printing unit, the apparatus including an inlet side and an outlet side, and including a set of conveying devices for moving items in a conveying direction and a method for regulating such an apparatus. The apparatus includes a device for aligning an article from one position to another position in relation to one or more reference points, and a device for fixing an item at a given position in relation to a stop. The method includes the steps: detecting an item; receiving and conveying the item; regulating a possible skew position of the item as the item is moved against a stop on the conveying device, where the item is acted on by one speed of the conveyor belt and moved into abutment on the conveying means at a lower speed; and fixing the item in the aligned position.

Claims

1. An apparatus for conveying a sheet-formed item, wherein the apparatus is a through-flow apparatus arranged after a digital printing unit, and a conveyor belt and before another finishing or printing unit, the apparatus including an inlet side and an outlet side, wherein the apparatus between the inlet side and the outlet side includes a set of conveying means for moving items in a conveying direction, where the conveying means include means for aligning an item from one position to another position in relation to one or more reference points, wherein the said means at least include one stop, the stop or stops arranged at right angles to the conveying direction, the conveying means including drive means for driving the conveying means at at least one conveying speed and further adapted for receiving an item conveyed at a receiving speed on a conveyor belt disposed in front thereof, and further including fixing means for fixing an item at a given position in relation to the stop or stops, wherein the apparatus includes means for regulating the speed of the conveying means as a function of the position of the stops on the apparatus and as a function of the position of an item.

2. Apparatus for conveying a sheet-formed item according to claim 1, wherein the apparatus includes fixing means where the fixing means are incorporated in the conveying means and include at least one vacuum source and a number of vacuum suction apertures.

3. Apparatus for conveying a sheet-shaped item according to claim 2, wherein the fixing means include conveying means with vacuum suction apertures where in an area in front of the stops there are arranged a first set of apertures having a first total suction capability, and where at one or more other areas on the conveying means there is arranged one or more sets of apertures with the same or with different suction capability, the apertures being connected to a vacuum source.

4. Apparatus for conveying a sheet-formed item according to claim 1, wherein the apparatus includes or is operatively connected to a printing unit, for applying ink and/or coating on printed sheet-formed items.

5. Apparatus for conveying a sheet-formed item according to claim 1, wherein the apparatus includes or is operatively connected to a drying station, the drying station including one or more drying means, including drying means that at least one of distribute hot air, emit heat radiation, use UV lamps for curing UV-setting ink and/or coating.

6. A method for regulating an apparatus for conveying a sheet-formed item, the apparatus being a through-flow apparatus arranged after a digital printing unit and before another coating or printing unit, the apparatus including an inlet side and an outlet side, wherein the apparatus between inlet side and the outlet side includes a set of conveying means for moving items in a conveying direction, wherein the method includes at least the following method steps: detecting an item before or at the inlet side, the item being conveyed at a first speed on a conveyor belt; activating the conveying means for receiving and conveying an item at a second speed corresponding to or lower than the first speed; regulating a possible skew position of the item on the conveying means as the item is moved to abut on one or two stops on the conveying means, the item being acted on by the first speed from the conveyor belt, and pressed against the stop or stops that are moved at the second speed that is lower relative to the first speed; fixing the item in the obtained and aligned position.

7. Method according to claim 6, wherein the method includes at least the following additional method steps: increasing the first speed over a given period of time/distance for maintaining as large spacing as possible between individual items; reducing the first speed to a lower level after a given period of time/distance; deactivating fixing means when the item encounters the subsequent coating or printing unit.

8. A method according to claim 6, wherein the method includes at least one of the following additional method steps: regulating side register based on input from one or more side sensors; regulating length register based on input from one or more length sensors.

9. Method according to claim 6, wherein the method includes at least one of the following additional method steps: conveying means with stops and mechanism for regulating side register and other means arranged in connection with the conveying means are returned to an initial position at a third speed, and are possibly stopped at a receiving position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a cross-section of the invention in a first position.

(2) FIG. 2 shows the invention in perspective view in a second position.

(3) FIG. 3 shows the invention in perspective view in a third position.

(4) FIG. 4 shows the invention in perspective view in a fourth position.

(5) FIG. 5 shows the invention in perspective view in a fifth position.

(6) FIG. 6 shows a cross-section of the invention in a sixth position;

(7) FIG. 7 shows a cross-section of the invention in a seventh position.

(8) FIG. 8 shows a cross-section of the invention in an eighth position.

DETAILED DESCRIPTION OF THE INVENTION

(9) In the explanation of the figures, identical or corresponding elements will be provided with the same designations in different figures. Therefore, an explanation of all details will not necessarily be given in connection with each single figure/embodiment as well as all elements are not necessarily provided with designations in all Figures.

(10) FIG. 1 shows a cross-section of the invention in a first position in which a conveying apparatus 1 with an inlet side 2 and an outlet side 3 stands ready to receive an item 4. The item 4, here in the shape of a sheet, is seen on a conveyor belt inlet 5 lying behind and moving the sheet 4 from a not shown digital printing unit and on to the subsequent process steps. The leading edge 6 is here on its way to abut on the stops 7 arranged transversely of the conveying means 8 on the conveying apparatus 1. After the conveying apparatus 1, immediately at the outlet side 3, there is arranged a flexographic printing unit 9, which here is arranged to apply a surface coating on the previously printed item 4. The flexographic printing unit 9 is shown simplified here, including an anilox roller/screen roller 10, a plate roller 11 with a plate 12, and a counter-pressure roller 13. After the flexographic printing unit 9 is seen a conveyor belt outlet 14 which can be the conveyor belt moving the items 4 on through a not shown drying station before the item lands in a not shown stacker.

(11) In the following, the invention will be described with reference to figures that are all more or less uniform. In principle, they show the same details, though with the conveying means 8 and thereby the stops 7, and the item 4 and also the plate roller 11 in different positions. The figures are thus an expression of selected situations in the course of an item from, e.g., a digital printing unit or from at stack of printed items 4 and through a conveying apparatus 1, in which alignment of the individual items 4 occurs before a printing or coating process 9.

(12) FIG. 2 shows a conveying apparatus 1 according to the invention in perspective view and in a different position. The item 4 is here very close to the inlet side 1 and almost in contact with the two stops 7.

(13) FIG. 3 shows a step immediately after the one shown in FIG. 2 where the item now rests on about a third of the conveying means 8, but is still not moved against the stops 7 as the conveying means so far are operated at a speed corresponding to the speed at which the item is received from the mentioned conveyor belt inlet 5.

(14) FIG. 4 shows a view immediately after the one shown in FIG. 3 where the speed of the conveying means 8 is reduced, and where the item/sheet 4 is thus brought to bear on the stops 7 and thereby is aligned. The speed can then be increased again, maintained or reduced more. At the same time an increase in the fixing of the item 4 occurs, and at the latest at the position appearing in FIG. 5, a regulation/adjustment in the side register and/or the length register in relation to the position of the plate is performed.

(15) The following figures, namely FIGS. 6-8, show an item 4 in different positions on its way through the flexographic printing unit 9. In FIG. 6, the leading edge 6 of the item is seen in contact with the plate roller 11 and with the counter-pressure roller 13 which now take over the conveying of the item 4. Furthermore, it is also seen that the conveying means 8 are on their way to the initial position as seen in FIG. 1. It is seen here only by the position of the stops 7 which is here seen at the underside of the conveying apparatus 1. The speed of the conveying means 8 and thereby of the stops 7 can be increased after the item 4 has been in contact with the flexographic printing unit 9, and be moved to the mentioned initial position at a markedly higher speed than the speed at which the item has been conveyed, if expedient.

(16) In FIG. 7 the item is seen on its way through the flexographic printing unit 9, and the conveying apparatus 1 is in initial position, but could very well be in the process of conveying a succeeding item 4.

(17) Finally, in FIG. 8 is seen that the item 4 has been applied a coating and is on its way to the subsequent conveyor belt outlet 14 which can move the item either through a not shown drying station or up to a such.