EP0790206B1 - Method of and device for automatically changing piles - Google Patents

Abstract

In the stack area, at least one first sensor (6) is arranged for securing the upper edge of the sheet stack (1) at a specific level. Measurement components are provided, which determine in the stack area beneath the first sensor at least a second position of the upper edge of the sheet stack at a second specific level. A control device is so arranged that the first sensor is connectable with the control for release of the inward movement of the sheet separating devices (4,5) and the measurement components for determining the second position at the second specific level are connectable with the control for release of the inward movement of the auxiliary stack bearer (2,3).

Description

The invention relates to a method for automatic changing a boom stack according to the preamble of claim 1 and a device according to the preamble of claim 4.

When printing printed sheets in a sheet-fed printing machine, the Rationalization and increased performance increasingly the use of facilities for automatic batch change brought into conversation. Both sheet piles are on to handle a sheet delivery as well as on a sheet feeder. Especially in the area of the sheet delivery of a sheet-fed rotary printing press are different Boundary conditions to be taken into account for the raw, not yet printed Printing material e.g. Paper in the area of the sheet feeder does not apply. Here plays especially a role that incoming sheets at high speed must be caught during a transition period and then discarded. At the Catch and temporarily hold these free-flying and only slightly braked incoming printed sheets must be taken into account that the printed sheets are printed and as a result, may no longer have their originally smooth contour. About that in addition, they are heavier, can be wavy and, above all, possibly have one color layer not yet completely dry.

• Zunächst werden die Bogentrennvorrichtungen, die an der Querseite des Bogenauslegers angeordnet sind, in den Bereich der von einem endlosen Kettenförderer freigegebenen und nach unten fallenden Druckbogen mit hoher Geschwindigkeit eingeschossen.
• Dabei schaffen diese Bogentrennvorrichtungen eine Lücke im Bereich der kontinuierlich weiter angelieferten Druckbogen.
• Die hochgehaltenen Druckbogen geben wiederum eine Lücke frei für das Einschieben von seitlich angeordneten und außerhalb des Bereiches des Auslegerstapels bereitgehaltenen Bogentragflächen.
• Die Bogentragflächen dienen als Träger für einen Hilfsstapel, der angehäuft wird, während eine mit einem vollen Bogenstapel beladene Palette aus dem Bogenausleger entfernt und eine neue leere Palette eingesetzt wird.
• Während die Bogentrennvorrichtungen die ankommenden Druckbogen seitlich hochhalten, werden die Bogentragflächen in den Bereich des Auslegerstapels eingefahren und übernehmen dabei die Druckbogen von den Bogentrennvorrichtungen.
• Die Bogentrennvorrichtungen werden zurückgezogen, wenn die Bogentragflächen komplett eingefahren sind, so daß sich dann die angehäuften Druckbogen auf den Bogentragflächen ablegen.

Beim Wechseln der Bogenstapel kommt es insbesondere bei etwas dünneren Bedruckstoffen dazu, daß der auf den Bogentrennvorrichtungen angehäufte Bogenstapel zu einer Markierung im Bereich der Auflage der Bogentrennvorrichtungen führt. Der Grund ist, daß man die Bogentrennvorrichtungen zur Verbesserung und Absicherung des Einschubs in eine Bogenlücke relativ schmal ausbildet. Daher bilden sie auch nur eine schmale Auflagefläche. Aus diesem Grund kann es leicht vorkommen, daß die auf den Druckbogen vorhandene Farbe auf den jeweils darauf liegenden oberen Druckbogen bzw. deren Rückseite abfärbt. Außerdem ist eine Verschiebung der Druckbogen durch die Auflage auf den Bogentrennvorrichtungen nicht immer zu vermeiden, so daß es zu Problemen bei der Bildung des Hilfsstapels kommen kann und teilweise sogar die Druckbogen beim Einfahren der Bogentragflächen zusammengeschoben, d.h. zur Mitte des Bogenstapels eingefaltet werden.From DE 41 31 015 A, which corresponds to the preamble of claims 1 and 4, a sheet delivery is known. This sheet delivery has a main stack elevator and an auxiliary stack elevator. The auxiliary stack elevator contains auxiliary stack carriers and sheet separation devices. When automatically changing a full stack of sheets accumulated in the sheet delivery for an empty pallet for further stacking of printed sheets, the following procedure is provided:

• First, the sheet separation devices, which are arranged on the transverse side of the sheet delivery, are shot at high speed into the area of the printed sheets released by an endless chain conveyor and falling down.
• These sheet separating devices create a gap in the area of the continuously supplied printed sheets.
• The printed sheets held up in turn open up a gap for the insertion of sheet support surfaces arranged laterally and held ready outside the area of the delivery stack.
• The sheet support surfaces serve as a support for an auxiliary stack that is piled up while a pallet loaded with a full stack of sheets is removed from the sheet delivery and a new empty pallet is inserted.
• While the sheet separating devices hold the incoming printed sheets up laterally, the sheet supporting surfaces are moved into the area of the delivery stack and take over the printed sheets from the sheet separating devices.
• The sheet separators are retracted when the sheet wings are completely retracted so that the accumulated printed sheets are then deposited on the sheet wings.

When changing the stack of sheets, especially in the case of somewhat thinner printing materials, the stack of sheets accumulated on the sheet separating devices leads to a marking in the region of the support of the sheet separating devices. The reason is that the sheet separating devices for improving and securing the insertion into a sheet gap are made relatively narrow. Therefore, they only form a narrow contact surface. For this reason, it can easily happen that the ink present on the printed sheets rubs off on the upper printed sheet lying on top of it or on the back thereof. In addition, a shift of the printed sheets due to the support on the sheet separating devices cannot always be avoided, so that problems can arise in the formation of the auxiliary stack and in some cases even the printed sheets are pushed together when the sheet supporting surfaces are retracted, that is to say folded in toward the center of the sheet stack.

GB 2 267 275 A describes a device for removing stacks from a Stacking station described. The device has a stack already formed retractable sword. This is done by a circulating belt within the stack and created a gap above the sword. The device therefore engages in the already finished batch. A separation and interim stacking of free falling sheets for transfer to a stack pallet is not described. The aim of the invention is to change a stack of sheets on one Improve sheet delivery.

The object of the invention is the procedure of changing the stack on one To improve the sheet delivery so that the process is both safer as well as for a larger area regarding the quality of substrates is applicable.

The task is characterized by the characteristics the method claim 1 and the device claim 4 solved.

In this case, due to the strongly interlocking sequence of the movement of sheet separating devices and auxiliary stack carriers and the movement of the main stack to be removed, there is less stress on the incoming printed sheets. Furthermore, the movement can be carried out much faster due to the new configuration, so that an auxiliary stack consisting of only a few printed sheets can form on the separating devices. This also makes the whole process quicker.
An essential advantage of the invention can be seen that the proposed stack changing device can also be used to process papers of poor quality, ie thinner papers. The generation of waste is avoided.

The sequence is explained in more detail below using an exemplary embodiment. In The process is shown schematically in the figures.

Fig. 1

die Anordnung der Stapelwechselvorrichtung

Fig. 2-6

verschiedene aufeinanderfolgende Phasen des Stapelwechselvorganges,

Fig. 7

die Endphase der Übernahme des Hilfsstapels und

Fig. 8

die Anordnung der Stapelwechselvorrichtung in einer Draufsicht im Ausleger.

In it show:

Fig. 1

the arrangement of the stack changing device

Fig. 2-6

different successive phases of the batch change process,

Fig. 7

the final phase of taking over the auxiliary stack and

Fig. 8

the arrangement of the stack changing device in a plan view in the boom.

In Fig. 1 is a stack changing device on a sheet delivery Sheet printing machine with those required for a so-called non-stop operation Facilities shown. Here, the sheet delivery is only partially shown here an endless chain conveyor system, also not shown, and a Main stacker provided so that printed sheets D from the printing units of Sheet printing machine conveyed to the sheet delivery, above a stacking area S can be released and filed. The printed sheets D are braked and placed freely on a sheet stack 1. The sheet stack 1 sits on a pallet, which in turn is carried by a main stacking hoist. The main stacking hoist ensures a continuous lowering of the pallet when increasing the sheet stack 1 through the supplied and deposited printed sheets D. On both sides of the area of the sheet stack 1 is an auxiliary stacking device at the level of the stacking area S. arranged. The auxiliary stacking device consists of two mirror images Arch wings 2, 3, i.e. from the transverse sides perpendicular to one of the Sheet printing machine predetermined sheet running direction arranged on the sheet delivery are. The sheet supporting surfaces 2, 3 are each in the stacking area with the aid of a drive S and movable out of it. Above and in each case the arch wings 2, 3 and thus also assigned to the stacking area S on both sides of the sheet stack 1 two sheet separators 4, 5 arranged. They consist of small ones Pneumatic cylinders, on the working cylinders of which pins are arranged, which in the Stacking area S are retractable. Furthermore, the sheet separating devices 4, 5 are in their Orientation to the position of the incoming printed sheets D slightly inclined so that when the sheet separating devices 4, 5 are retracted, a support surface that is curved downward for the incoming printed sheets D. Furthermore, with the sheet delivery Control devices connected to the sequence of movements described Sheet separators 2, 3, sheet wings 4, 5 and main stacker control each other.

The sheet separators 4, 5 are in the area of side guides 10, 11 arranged, which serve an exact stack formation of the sheet stack 1. For quick and Gentle handling of the printed sheets D when changing stacks is therefore the following procedure intended:

In Fig. 1 the initial state of the sheet stack 1 is shown in the sheet delivery. The Sheet stack 1 is filled almost up to its maximum stack height, the sheet supporting surfaces 2, 3 are on hold and sheet separators 4, 5 are on hold. At Reaching a certain height H1 of the sheet stack 1, e.g. from the position of the Main stacking device can be derived, a start signal is given. As good as can the printer also trigger this signal by hand if this is from the Workflow seems appropriate. The start signal causes the sheet stack 1 is lowered in direction A. The lowering movement takes place with a relatively slow Lowering speed V1 in order not to disturb the stack formation too much.

2 shows the second step of the batch change process. During the Downward movement of the sheet stack 1 when the sensor 6 is reached Sheet separating devices 4, 5 shot into the area of the falling printing sheets D. This process is controlled with respect to the functions of the printing press so that the Time at which the sheet separating device 4, 5 was shot into the area of a gap must fall between the falling printed sheets D. This control process is for example to match the movement of the chain conveyor system or can be derived from this become. After the sheet separation devices 4, 5 are shot in, the Lowering speed increased to V2 to match the top of the sheet stack 1 to get faster into the area of the arch wings 2, 3.

3 shows the third step of the batch change process. It is shown that two printed sheets D are now deposited on the sheet separating devices 4, 5 to have. They lie in an arc with their central part on the surface of the sheet stack 1 on. In the meantime, the movement to lower the main stack is when a second one is reached Sensor 7 has been stopped at a height H2. The position corresponding to the height is H2 also derivable and approachable from the movement of the main stacking hoist, so that one Device in the drive of the main stacker can serve as a sensor. To this Defined point in time is the retracting movement of the arch wings 2, 3 in the direction started for sheet stack 1. This causes the two arch wings 2, 3 in the stacking area S above the sheet stack 1 from the side edges move in. Through the arranged above the arch wings 2, 3 Side guides 10, 11, the falling printed sheets D are also on the Sheet separators 4, 5 still well aligned.

4 shows the fourth step of the batch change process. There are more in the meantime Printed sheets have been deposited on the sheet separators 4, 5. Now the Changes in the movement between the sheet separators 4, 5 and Arch wings 2, 3 shown. While the arch wings 2, 3 now continue in the Retract the area of the sheet stack 1, they reach a third sensor 8, which in turn causes the sheet separators 4, 5 to be withdrawn from the stacking area S. become. The sensor 8 is arranged so that it only the position of the sheet support surfaces 2, 3 registered when they have already entered the stacking area S a little. A The possibility of realizing these features is shown in FIG. 8. During the Reversal of the movements of arch wings 2, 3 and arch separators 4, 5, an auxiliary stack 9 continues to form on the arch support surfaces 2, 3.

5 shows the fifth step of the batch change process in the further sequence. After this the sheet separators 4, 5 are withdrawn, they still fall at this time relatively few printed sheets D of the auxiliary stack 9 placed on the front ends of the in the arch area 2, 3 entering the stacking area S. Since the arch area 2, 3 very are arranged close above the surface of the still standing sheet stack 1 the printed sheets D of the auxiliary stack 9 are only slightly lowered, while the Ends of the arch wings 2, 3 approach each other. The auxiliary stack 9 is therefore also even with only partial support of the printed sheets D on the sheet support surfaces 2, 3 relative flat on the sheet supporting surfaces 2, 3 and the surface of the sheet stack 1. The Printing sheets D therefore provide little resistance to the retracting sheet support surfaces 2, 3 opposite. There is a risk that the printed sheets will be pushed inwards prevented because the stability of the auxiliary stack 9 in the direction of its surface area is already sufficient to take the force effect from the friction between arch wings 2, 3 and sheet D to overcome.

6 is the end position of the phase of the auxiliary stack formation during the stack change process shown. After the arch wings 2, 3 complete from both sides are retracted, the printed sheets D of the auxiliary stack 9 are now completely flat the arch wings 2, 3. In this state at the latest, the sheet stack can be started 1 can be lowered completely.

7 shows the process for ending the stack change. After this Lowering from the position at the stack area S becomes the sheet stack 1 from the Sheet delivery is removed and replaced by an empty pallet 12. If the empty palette 12 is lifted up with the main stacker up to below the arch wings 2, 3, the sheet support surfaces 2, 3 are laterally pulled out again from the stacking area S. The auxiliary stack 9 falls on the empty pallet 12 and the sheet stacking can be done like continue running as usual. For example, the sensor 8 or other detects this Operating safety elements such as Limit switch that the arch wings 2, 3 to the stacking area S are removed. Thereafter, the main stacker can lift the pallet 12 in lift an optimal position for the sheet deposit between the side guides 10, 11. This positioning takes place according to the positioning with regard to the heights H1 and H2 when descending the sheet stack 1.

The method is supplemented by a corresponding control of the known Device for managing the batch change. The arrangement of the elements is over Figures 1 to 6 can be seen. The assignment of the movements between the Sheet separation devices 4, 5 and the sheet wings 2, 3 and the movement of the Main stacking hoist is via sensors 6, 7, 8 in the area of the upper edge of the Sheet stack 1 and controlled in the area of the sheet wings 2, 3. First is a Sensor 6 provided that detect the surface or top edge of the sheet stack 1 and the shooting-in movement of the sheet separating devices 4 in a certain position, 5 controls. This should happen when the sheet stack 1 just below the Sheet separators 4, 5 is lowered. This ensures that printed sheets only then D fall on the sheet separators 4, 5 when the sheet stack 1 is already a part has undergone its lowering movement. This means that only a few printed sheets D are noticeable the sheet separators 4, 5 and thus the load on the printed sheet D in Area of the narrow supports on the sheet separators 4, 5 less.

Another sensor 7 is arranged at the point where the surface or upper edge of the sheet stack 1 is to have the lower position during use of the auxiliary stacking device, which was designated as height H2. In this position H2 of the second sensor 7, the sheet stack 1 is stopped and at the same time the sheet support surfaces 2, 3 are set in motion for insertion into the area of the sheet stack 1. This control ensures that a quick transition to retracting the sheet support surfaces 2, 3 is achieved and at the same time only a few printed sheets D come to rest on the sheet separating devices 4, 5, with the positive effects mentioned above.
To control the position H2, a signal for a travel path for the main stacking hoist can also be derived, which has to be traversed after the position H1 has been reached until the downward movement has stopped. The sensor 7 would thus be seen as part of the main stacking hoist.

Finally, a third sensor 8 is assigned to the arch wings 2, 3. This sensor 8 detects the retracting movement of the arch wings 2, 3. The sensor 8 serves the To control sheet separation devices 4, 5 and the sheet separation devices 4, 5 pull when the arch wings 2, 3 are so far below the auxiliary stack 9 are retracted so that they can accommodate it. When pulling the Sheet separators 4, 5 then drop the accumulated printed sheets D onto the tight standing above the sheet stack 1 sheet wings 2, 3 and are relatively flat on the sheet stack 1 and the sheet wings 2, 3. This improves it Insert the sheet support surfaces 2, 3 considerably, since the printed sheets D of the auxiliary stack 9 are only slightly arched or bent downwards and when pushed in Arch wings 2, 3 can hardly oppose resistance. The friction forces are minimized, the arches are stabilized in their surface area and the Force relationships between sheet support surfaces 2, 3 and printed sheet D of the auxiliary stack 9 become clear. On the one hand, the printed sheets D are therefore no longer available moved relative to each other and on the other hand can not be pushed together inwards become.

In particular, however, FIG. 8 also shows a top view of the stacking area S, how the sheet support surfaces 2, 3 move relative to the sheet stack 1. Are shown the sheet support surfaces 2, 3 left and right of the sheet stack 1 and the side guides 10, 11, which delimit the stacking area S. Particular attention should be drawn to the sensor 8 which is on the side guide 11 is fastened and with the front edge of the sheet support surface 3 cooperates. The position recognized by the sensor 8 is shown in broken lines. there it can be seen that the sheet supporting surfaces 2, 3 already extend into the stacking area S. and so the printed sheets D can take over.

It is also important that the sensors 6, 7 and 8 with one of the side guides 10, 11th are connected. The sensors 6, 7, 8 are thereby set to different sheet formats always correctly positioned. This ensures that the Print sheet D or sheet stack 1 always and with any format setting safely guided and clearly recognized even when changing stacks.

The takeover of the auxiliary stack 9 by the arch support surfaces 2, 3 is thus thus much safer, runs faster and generates fewer relative movements between the printed sheet. This eliminates the problems of marking the ink on the Underside of overlying printed sheets D and pushing together printed sheets D safely avoided with lighter substrates. The work area of the facility will significantly expanded compared to the known process.

Reference symbol list:

S

Stacking area

D

Printed sheet

H1

height

H2

height

A

Lowering movement

1

Sheet stack

2nd

Arch wing

3rd

Arch wing

4th

Sheet separator

5

Sheet separator

6

first sensor

7

second sensor

8th

third sensor

9

Auxiliary pile

10th

Side guide

11

Side guide

12th

palette

Claims (9)

1. Process for changing sheet piles (1) in a delivery of a sheet printing press with auxiliary pile carriers arranged in the delivery and which can be pushed into the pile region (S) of the delivery above a sheet pile (1), as well as sheet separating devices (4, 5) arranged above the auxiliary pile carriers (2, 3), wherein, on reaching a limiting pile height, first the sheet separating devices (4, 5) can be moved into the pile region (S) and thereafter, while printed sheets (D) from the sheet printing press are continuously further deposited in the delivery, the auxiliary pile carriers (2, 3) can be moved into the pile region (S) to form an auxiliary pile (9) and then after the readying of a new empty pile support (12) for deposition of the auxiliary pile (9) on to the pile support (12) are movable again out from the pile region (S), characterised in that

   after reaching the limiting pile height, the sheet pile (1) is lowered with a first lowering speed,

   the sheet separating devices (4, 5) are moved in during the lowering movement of the sheet pile (1) with the first lowering speed into the pile region (S),

   after the moving in of the sheet separating devices (4, 5) into the pile region (S), the sheet pile (1) is lowered with a second larger lowering speed,

   the lowering movement of the sheet pile (1) is stopped after reaching a second height which lies closely below the lower side of the auxiliary pile carriers (2, 3),

   directly thereafter, the auxiliary pile carrier (2, 3) are moved into the pile region (S), and

   with the lowering movement of the sheet pile (1) rendered stationary, during the movement to introduce the auxiliary pile carriers (2, 3) into the pile region (S), the sheet separating devices (4, 5) are pulled out from the pile region (S).
2. Process according to Claim 1, characterised in that

   the sheet separating devices (4, 5) are moved out from the pile region (S) dependent upon the position of the auxiliary pile carriers (2, 3) moving into the pile region (S).
3. Process according to Claim 1, characterised in that

   the sheet pile (1) is lowered or raised by means of a main pile lifting unit,

   by means of the main pile lifting unit, an empty palette (12) is raised until underneath the auxiliary pile carriers (2, 3),

   the auxiliary pile (9) is deposited on to the palette (12) with the main pile lifting unit stationary, and

   the new sheet pile (1) on the palette (12) after the transfer of the auxiliary pile carriers (2, 3) dependent upon the position during the movement of the auxiliary pile carriers (2, 3) moving out from the pile region (S) is raised again in the pile region (S) between side guides (10, 11).
4. Device for carrying out the process for changing sheet piles (1) in a delivery of a sheet printing press in accordance with Claim 1,

   with means arranged in the delivery for lifting and lowering a sheet pile (1) or for preparing a new empty pile support (12), for example a main pile lifting unit,

   furthermore with auxiliary pile carriers (2, 3) which can be moved into the pile region (S) of the delivery above the sheet pile (1),

   as well as with sheet separating devices (4, 5) arranged above the auxiliary pile carriers (2, 3) and likewise movable into the pile region (S),

   with means for detecting a limiting pile height,

   and with means (10, 11) for the lateral guidance of printed sheets (D) in the pile region (S) during the deposition of the printed sheets (D) on to the sheet pile (1),

      characterised in that

   at least one first sensor (6) is fitted in the pile region (S) to detect the upper edge of the sheet pile (1) at a first height,

   measuring means are provided which, in the pile region (S) below the first sensor (6), detect at least one second position of the upper edge of the sheet pile (1) at a second height (H2) and that the measuring means comprise at least one second sensor (7) which is arranged to detect the upper edge of the sheet pile (1) in a position closely below the auxiliary pile carriers (2, 3) at the second height (H2),

   fitted to the auxiliary pile carriers (2, 3) is at least one third sensor (8) detecting the position of the auxiliary pile carriers (2, 3) during the moving in or moving out movement,

   that a control device is provided of such a type that

   the first sensor (6) can be connected with the control for triggering the moving in movement of the sheet separating devices (4, 5),

   the measuring means for determining the second position at the second height (H2) can be connected with the control for triggering the moving in movement of the auxiliary pile carriers (2, 3),

   the third sensor (8) can be connected with the control for triggering the moving out movement of the sheet separating devices (4, 5), and

   the means for lifting and lowering the sheet pile (1), for example the main pile lifting unit, can be driven with a first lowering speed and a second larger lowering speed.
5. Device according to Claim 4, characterised in that the first sensor (6) is arranged below the sheet separating devices (4, 5) in the region of the side guides (10, 11).
6. Device according to Claim 4 or 5, characterised in that the second sensor (7) is provided as a sensor detecting the position of a drive movement of the main pile lifting unit with respect to the lifting movement of the sheet pile (1).
7. Device according to Claims 4 to 6, characterised in that the third sensor (8) is fitted to a marking on the auxiliary pile carriers (2, 3) with reference to its direction of movement.
8. Device according to Claims 4 to 6, characterised in that the third sensor (8) is fitted to at least one or both of the auxiliary pile carriers (2, 3) which is turned back in the direction of movement with respect to the sheet pile (1).
9. Device according to one or all of Claims 4 to 8, characterised in that at least the first (6) and the third sensor (8) are connected with elements which can be adjusted to the sheet format.

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