EP1471022B1 - Collecting device and method for operating the same - Google Patents

Abstract

Collecting device for collating sheets (14), especially printed paper sheets, to form a stack of sheets comprises a rotating body (1) rotatably mounted about its axis (A), a drive for rotating the rotating body, at least one securing mechanism (4) for securing a number of sheets in the form of a stack in the region of the front edges (15) of the sheets on the outer surface (3) of the rotating body, and control devices for actuating the securing mechanism. An arriving sheet during rotation of the rotating body is secured by the securing device so that its front edge is held flush with the front edge of the stack. An independent claim is also included for a process for operating the above collecting device.

Description

The invention relates to a collecting device and a method for its operation according to claims 1 and 9, respectively.

For the production of printed matter, e.g. Newspapers or brochures, especially in short runs, are increasingly being used for digital printing presses. These usually print all the sheets for a printed product sequentially in succession. To complete the printed product, the sheets must be collected, possibly after a cutting operation. Collecting is understood to mean the superimposition of sheets into sheet stacks in which the individual sheets are aligned with one another at least at one edge. This is followed by the further steps of folding and / or stitching the pile of sheets.

Also conventionally, ie with conventional rotary printing machines, printed sheets must be collected to produce a printed product. For this purpose, collecting devices are known which summarize the previously printed in large quantities sheets. Known collection devices have, for example, a plurality of pockets or carriers, which are guided past several feed stations. In this case, a specific sheet is fed at each feed station, so that finally each bag contains all the sheets of the product in question. These collection devices are not well suited for stacking sequentially printed and delivered sheets.

From the EP-A 1 209 000 and the EP-A 1 219 556 Methods for the production of a printed product are known in which the sheets are printed with a digital printing press and combined in a collecting device into sheet stacks. The collecting device is connected, for example, between a cross cutter, which is connected downstream of a digital printing system, and a folding station or another processing member. The collecting device according to the EP-A 1 219 556 forms a stack of sheets by the continuously fed sheets with a gripping member, such as a sucker, taken and deposited on a fixed, stationary place each other. A plurality of gripping members is moved along a closed orbit. The orbit has a horizontally extending portion whose length must exceed the length of an arc substantially. This leads to a large amount of space. The following points are also associated with the stationary collecting station for the stack of sheets: An incoming sheet must be braked considerably before it is deposited. Especially at high processing speeds, this leads to a heavy stress on the sheet, which is why the process reliability can be impaired, especially in sensitive papers. Process reliability can only be increased by using complex auxiliary functions, such as springs, brake dragging, vacuum brakes, braking of the gripping members. Finally, the finished stack of sheets must be greatly accelerated so that it is removed from the collection device before another sheet is dropped. An acceleration to a speed greater than the feed rate of the sheets to the collecting station is necessary. The production speed is therefore limited by the collection device.

Furthermore, the disclosure US-A-2002/0074716 a collecting device according to the preamble of claim 1.

The invention is therefore based on the object to provide a collecting device that allows high production speeds with a high process reliability, a gentle treatment of the sheets and reduced space requirements. Furthermore, a corresponding operating method should be made available.

The object is achieved by a collecting device and an operating method with the features of claims 1 and 7. Advantageous developments of the invention will become apparent from the dependent claims, the description and the drawings.

The inventive collecting device comprises a rotary body which is rotatably mounted about its axis and can be set in rotation with a drive. Furthermore, there is at least one retaining mechanism for picking up and holding bows. Whose interacting with the arc elements are arranged in the region of the outer surface of the rotating body. The retaining mechanism serves to hold a plurality of sheets present in the form of a sheet stack in the region of their leading edge in the direction of rotation and to hold a new sheet also at its leading edge and add to the sheet pile. In this case, the leading edge of the new sheet is flush with the leading edges of the sheets of sheet stack, especially by means of a stop. The lateral alignment of the sheets can be done by other means. For actuating the retaining mechanism are suitable control means. Picking up sheets, stacking and discharging the stack take place during rotation of the rotating body. This eliminates the disadvantages associated with a stationary stacking position, in particular the Decelerate and accelerate the bows again. The bows are processed in the river. Since the rotary body only has to have a circumference which is greater than or equal to the length of the largest sheet format to be processed, the entire apparatus is also very space-saving. However, it is also possible to provide distributed over the circumference a plurality of retaining mechanisms to simultaneously form a plurality of sheet stacks.

The collecting device is particularly suitable for processing individual, sequentially printed in particular in the digital printing process and continuously conveyed sheets. However, it can also generally be used to form small stacks, e.g. to collect conventionally printed and / or already folded sheets, small stacks and / or scaly-like conveyed arcs.

Fig. 1a

eine Sammelvorrichtung mit einem ersten ankommenden Bogen;

Fig. 1b

die Sammelvorrichtung aus Fig. 1a in Seitenansicht

Fig. 1c

eine vergrösserte Darstellung des Schliessmechanismus;

Fig. 2a-c, 3a-c,4a-c, 5a-c, 6a-c, 7a-c

die Sammelvorrichtung aus Fig. 1a-c in verschiedenen Momentaufnahmen bei der Durchführung des erfindungsgemässen Verfahrens.

An example of the invention is illustrated in the drawings and described below. It shows purely schematically:

Fig. 1a

a collection device with a first incoming sheet;

Fig. 1b

the collection device Fig. 1a in side view

Fig. 1c

an enlarged view of the closing mechanism;

Fig. 2a-c, 3a-c, 4a-c, 5a-c, 6a-c, 7a-c

the collection device Fig. 1a-c in different snapshots at the Implementation of the inventive method.

The figures show a collecting device according to the invention in various snapshots and in different views when carrying out the method according to the invention. The Figures 1a-7a each show a view of the collecting device including a feeder 12 and a Wegführeinrichtung 13. Die Figures 1b-7b each show a side view of the device. The Figures 1c-7c each show a section of the corresponding Figure 1a-7a , in which the retaining mechanism 4 is shown enlarged.

The core of the collecting device is a rotary body 1, which in the present case consists of three disc-like segments 2 which are arranged coaxially to a rotation axis A on a common shaft 16. The segments 2 each have a disk-like base body 2a with a widened peripheral edge 2b. The three edge surfaces including the imaginary connecting surfaces located therebetween define an outer surface 3 of the rotating body, against which a sheet 14 bears completely or partially during the collecting process. The outer surface 3 is in this case cylinder jacket-shaped. For producing such an outer surface 3, a rotary body in the form of a solid or hollow cylinder or a body which spans a cylindrical outer surface in the peripheral region can also be used. For example, the rotary body shown in the figures can also consist of more than three segments. Rotary body 1 is understood to mean a body rotatable about the axis A, which is preferably, but not necessarily, substantially rotationally symmetrical.

A retaining mechanism 4 comprises a set of first retaining elements 5 and a set of second retaining elements 6, one of which is assigned to a segment 2. They are actuated by control or drive means not shown here, for example by a link control or an electronically controlled mechanical drive. The first and second retaining elements 5, 6 have the shape of an L-shaped bent finger 7, the pivotable about a parallel to the axis of rotation A pivot axis B and slightly movable in the radial direction. The bent end 8 has a rotary body 1 facing first surface 8a, between which and the rotary body 1, a sheet 14, 14 'can be clamped. The slightly inclined thereto extending, the rotary body 1 facing away from the second surface 8b can also be below a sheet 14, 14 'are (see retaining member 6 in Fig. 2b ). A substantially radially extending stop surface 8c (see Fig. 3c ) serves, for example, as a stop for aligning the leading edge 15 of an incoming sheet 14, 14 '. The holding elements 5, 6 project slightly beyond the rotary body 1 in the radial direction. The edge 2b of the segments 2 has for this purpose recesses 2c, through which the pivoting movement is made possible.

The feed device 12 in the form of a conveyor belt runs horizontally and approaches the rotary body 1 as viewed in the direction of rotation R approximately 45 ° before the vertex S, so that an arc with only slight bending, ie substantially tangential, can be transferred to the rotary body 1. Between the feeder 12 and the rotary body 1 is the takeover area 9. The in Fig. 1b and 4b shown position of the rotating body 1, in which the retaining elements 5, 6 located in the transfer area 9 is referred to as takeover position.

The Wegführeinrichtung 13 in the form of a conveyor belt also extends horizontally and begins on the rotary body 1 in the direction of rotation R seen about 30 ° to the apex S, so that a sheet under only slight bending, ie substantially tangentially, can be taken over by the rotating body 1. Between the Wegführeinrichtung 13 and the rotary body 1 is the delivery area 10. The in Fig. 6b shown position of the rotating body 1, in which the retaining elements 5, 6 are located in the delivery area 10, is referred to as delivery position. By means of a discharge device with a plurality of discharge elements 11, which extend about a pivot axis C (B) running parallel to the axis of rotation A (FIG. Fig. 6c ) are pivotable, the front edge of a sheet 14, 14 'after pivoting away the retaining elements 5, 6 are lifted off the rotary body 1 and transported away. The discharge elements 11 are arranged next to and between the segments and engage in the activated state an arc ( Fig. 6b ) to make it stand out.

The function of the collecting device is described in more detail below: A sheet 14, which comes from a printing press or a cross-cutter, is fed with the feed device 12 to the rotary body 1 rotating about the axis A ( Fig. 1a-c ). The rotary body is driven so that it is in the transfer position when the leading edge 15 of the sheet 14 reaches the rotary body 1 ( Fig. 2a-c ). The first retaining elements 5 are slightly moved radially outward, so that their first surfaces 8a with the outer surface 3 a receiving gap 17 (FIG. Fig. 1c ) forming in Peripheral direction is limited by the stop surface 8c. The second receiving elements 6 abut against the outer surface 3 and could, for example, fix an already recorded sheet or stack of sheets (cf. Fig. 5a-c where this is the case for the first retaining element 5). Thus, the sheet 14 slides over the second retaining elements 6 in the receiving gap 17 formed by the first retaining elements 5. It is clamped there by the first retaining element 5 is moved inwardly in the radial direction. At the same time the rotary body 1 is further rotated ( Fig. 2a-c ). In the course of a complete revolution, the sheet 14 is wound to save space on the rotary body 1.

Upon further rotation of the rotary body 1 in a first intermediate position, the second retaining elements 6 are deactivated, ie pulled out by pivoting under the held by the first retaining element 5 sheet 14 ( Fig. 3a-c ). If the second retaining element 6 have already held a stack of sheets fixed, it is now held solely by the first retaining element 5.

The second retaining element 6 now pivots back into its starting position, but remains outwardly offset in the radial direction, so that a further conveying gap 17 'is formed, which can receive a further sheet 14' ( Fig. 4a-c ). In these, the further sheet 14 is received and clamped ( Fig. 5a-c ). Since the abutment surfaces 8c of the first and second retaining elements 5, 6 are in the same position in the circumferential direction, the leading edges 15, 15 'are precisely aligned with each other. Since the first and second retaining elements 5, 6 are constructed identically in the present example, this situation corresponds to that Fig. 1a-c and 2a-c ,

In differently constructed first and second retaining elements (not shown here), the entire sheet stack including the newly recorded bow from the first intermediate position held by both retaining elements and from a second intermediate position only by the second retaining member, while the first retaining member for receiving a new sheet ready is done. Alternatively, the entire stack of sheets may be kept constantly e.g. be held by electrostatic charge, needles or external guide rollers and serve the first retaining element substantially only as a stop for the leading edge of a newly recorded bow. A stop is then dispensable when feeder and rotary body are synchronized so that the leading edges are always in the same place with respect to the retaining element or to the leading edge of the already deposited sheets. In this case, it is sufficient that the retaining mechanism holds the new sheet in the position in which the leading edges are flush with each other.

The in the Figures 1-5 The process shown may be repeated until all the sheets 14, 14 'to be combined into a stack are at least partially wound up on the rotary body 1. In the present example, the further sheet 14 'is already the last of the stack. It therefore does not complete rotation of the rotating body and is not fully wound up. Before or upon reaching the delivery position, the discharge elements 11 are activated and the currently active holding elements 5, 6 deactivated, so that the entire stack is discharged ( Fig. 6a-c ). After again reaching the transfer position, ie still while the first stack of sheets in the region of the rotary body. 1 the first sheet 14 "of a new sheet pile can be picked up ( Fig. 7a-c ).

The stack is usually removed by the centrifugal force, but can also be adopted by fingers or rotating grippers or other techniques known per se. Preferably, by suitable means, e.g. electrostatic charging, crimping or external guide rollers, ensuring that the sheet stack remains together during transport with the removal device 13.

The web speed v _B of the elements of the retaining mechanism 4, in this case the receiving gap 17, 17 'or the abutment surface 8c which takes over the arches, is preferably non-uniform during one revolution. It is preferably before and when reaching the transfer position lower than the feed speed v _{z of} the sheets 14, 14 'on the feeder 12, so that the leading edges 15, 15', for example by striking the stop surface 8c, flush with each other can be added. Subsequently, the rotary body is preferably slightly accelerated so that it is on arrival of the next leading edge again in the transfer position.

Preferably, the rotational speed of the rotating body 1 is adjusted to the distance the leading edges 15, 15 'of the sheets have in feeding to the collecting device. If, for example, the document set contains individual shorter sheets, such as half sheets usual in a newspaper, the peripheral speed of the rotating body 1 is substantially increased over at least part of a rotation, so that the rotary body the takeover position is reached on arrival of the next leading edge with the correct speed. The same effect can be achieved by adjusting the distance that the leading edges on the feeder have, for example by adjusting the printing speed.

Claims (12)

1. Gathering apparatus for collating sheets (14, 14', 14''), in particular printed paper sheets, for forming a sheet stack, having a rotational body (1) which is mounted such that it can be rotated about its axis (A), a drive, by way of which the rotational body (1) can be set in rotation, at least one retaining mechanism (4) which is capable of retaining a plurality of sheets (14, 14', 14") in the form of a sheet stack on the outer face (3) of the rotational body (1) in the region of their leading edge (15, 15') in the rotational direction, and control means for actuating the retaining mechanism (4), an incoming sheet (14, 14', 14'') being received and retained by the retaining mechanism (4) during the rotation of the rotational body (1), in such a way that its leading edge (15, 15') is received in a flush manner with respect to the leading edge of the sheet stack, characterized in that the retaining mechanism (4) comprises at least one first retaining element (5) and at least one second retaining element (6) which are of identical construction and can be actuated independently of one another, the first and second retaining element (5) comprising in each case one pivotable finger (7) which, in an open state of the retaining element (5), forms a stop for the leading edge (15, 15') of the incoming sheet (14, 14', 14") by way of a stop face (8c) and holds the sheet (14, 14', 14") together with the sheet stack in a closed state of the retaining element (5).
2. Gathering apparatus according to Claim 1,
   characterized in that the stop faces (8c) of the first and second retaining elements (5, 6) are situated at the same location in the circumferential direction of the rotational body.
3. Gathering apparatus according to Claim 1 or 2, characterized by a feed device (12) for feeding sheets (14, 14', 14") in a plane which extends substantially tangentially with respect to the outer face (3) of the rotational body (1), the feed device (12) preferably comprising a conveyor belt or a conveyor table.
4. Gathering apparatus according to one of Claims 1 to 3, characterized by a guiding-away device (13) for guiding away sheet stacks in a plane which extends substantially tangentially with respect to the outer face (3) of the rotational body (1), the guiding-away device preferably comprising a conveyor belt or a conveyor table.
5. Gathering apparatus according to one of Claims 1 to 4, characterized in that the circumference of the rotational body (1) is at least as large as the length of the largest sheet format to be processed by way of the gathering apparatus.
6. Gathering apparatus according to one of Claims 1 to 5, characterized in that the drive is capable of driving the rotational body (1) in a non-uniform movement.
7. Method for operating a gathering apparatus according to Claim 1 having the following steps:

   a) actuation of the retaining mechanism (4) in a transfer position of the rotational body for retaining at least one fed sheet (14, 14', 14'') in the region of its leading edge (15, 15') in the rotational direction, the sheet (14, 14', 14'') being received and retained in such a way that its leading edge (15, 15') is flush with respect to the leading edge of the sheets (14, 14', 14'') which have possibly already been received by the retaining mechanism (4);

   b) rotation of the rotational body (1) as far as a delivery position of the rotational body (1);

   c1) rotation of the rotational body (1) as far as the transfer position of the rotational body (1) and repetition of steps a) and b) if the number of gathered sheets (14, 14', 14'') is less than the number of sheets (14, 14', 14'') to be gathered;
   or

   c2) actuation of the retaining mechanism (4) in the delivery position of the rotational body (1) for releasing the retained sheet or sheets (14, 14', 14") if the number of gathered sheets (14, 14', 14") corresponds to the number of sheets (14, 14', 14") to be gathered,

   characterized in that the at least one first and second retaining elements (5, 6) are actuated in such a way that the following is true:

   - in the transfer position, one of the two retaining elements (5, 6), namely the first or the second retaining element (5, 6), forms the stop for the leading edge of an incoming sheet, while the other retaining element (6, 5) possibly retains a sheet which has already been received;

   - from the transfer position as far as an intermediate position, the newly received sheet is held only by that retaining element (5, 6) which forms the stop for the leading edge of the said sheet in the transfer position;

   - from the intermediate position as far as the transfer position, that retaining element (5, 6) which formed the stop for the newly received sheet in the transfer position holds the newly received sheet and the sheets which have possibly already been received below it, while the other retaining element is ready to receive and to retain a further sheet by forming the stop for the leading edge of the said further sheet.
8. Method according to Claim 7, characterized in that the rotational speed of the rotational body (1) is adapted to the spacing of the leading edges (15, 15') of the sheets (14, 14', 14'') when they are fed to the gathering apparatus.
9. Method according to Claim 7, characterized in that the rotational speed of the rotational body (1) is non-uniform.
10. Method according to one of Claims 7 to 9, characterized in that the sheets (14, 14', 14") are fed continuously to the gathering apparatus at a feed speed v_z and the rotational speed of the rotational body (1) is adapted to the feed speed v_z in such a way that the path speed v_B of those elements of the retaining mechanism (4) which accept the sheets (14, 14', 14") is lower before and when the transfer position is reached than the feed speed v_z and is preferably increased after the transfer of the sheets (14, 14', 14").
11. Use of a gathering apparatus according to one of Claims 1 to 6 for gathering sequentially printed and fed sheets.
12. Use of a gathering apparatus according to one of Claims 1 to 6 for producing a printed product, in particular a newspaper, by means of a digital printing press.

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