DE102020124433A1 - Feeder of a sheet-processing machine and method for supporting sheet separation in a feeder of a sheet-processing machine - Google Patents

Abstract

A stack of sheets to be processed can be accommodated in a sheet feeder according to the invention of a sheet processing machine, with at least one transport tool being provided, through which an uppermost sheet of a stack accommodated on the stacking plate is transported in a sheet transport direction away from the stack into a transport path adjoining downstream is transportable. On the downstream side of the stack there is provided a blower by which sheets of the stack are blown in the horizontal direction, i. H. viewed across the width of the stack can be subjected to blowing air at several points or sections or continuously over a width corresponding to at least half the sheet width in the region of their front sheet edge. The invention also relates to a method for supporting sheet separation in a sheet feeder of a sheet processing machine.

Description

The invention relates to a feeder of a sheet processing machine and a method for supporting sheet separation in a feeder of a sheet processing machine according to the preamble of claim 1 or 10.

Feeders are used on sheet-fed printing machines in order to separate sheets of different material that have been prepared on stacks and feed them to the printing machine. The sheets are separated and fed by so-called sheet separators. In the case of sheets still lying on the stack, in particular sheets of thin materials, their front cut edges can be hooked into one another. In this case, the upper sheet is difficult to pull off the stack and may then tear the lower sheet with it in the movement. This can lead to errors such as crooked, late or double sheets in the following sheet or in the sheet fed out.

From the DE 197 45 301 A1 a feeder of a sheet-fed printing press is known, with a blower element extending over the height of the stack and having one or more air outlet openings extending over the height of the stack being provided for pre-loosening the sheets on at least the front side of the stack, ie on the front side facing the printing units. On the long side of the stack, a further blowing element that can be displaced along the long side can be provided.

Loosening up too early can possibly lead to renewed settling, spatially limited blowing to incomplete loosening, especially in the edge areas. Blowing in only at certain points can form air cushions between the sheets, but there is a risk that the edges will not be separated across the width.

In addition, particularly in the case of less stiff and/or thin sheets, when the sheet is being conveyed out of the feeder, the leading edge may buckle or sag and get caught on a flap and/or downstream conveying roller that may be provided.

The object of the invention is to create a feeder for a sheet processing machine and a method for supporting sheet separation in a feeder for a sheet processing machine.

The object is achieved according to the invention by the features of claim 1 and 10 respectively.

The advantages that can be achieved with the invention are, in particular, that a higher quality is achieved when the sheets are fed into the processing machine, in particular the printing machine. In particular, the risk of the above-mentioned Snagging and an associated position error reduced. Alternatively or preferably additionally, the risk of twisting and getting caught is averted or at least reduced by upwardly directed blown air streams.

In the embodiment of the invention, the feeder of a sheet-processing machine - e.g. B. on a vertically adjustable stacking plate on a frame - a stack of sheets to be processed can be accommodated, at least one transport tool being provided by which an uppermost sheet of an accepted stack can be transported in a transport direction away from the stack into a transport path that follows downstream. On the downstream side of the stack there is provided a blower by which sheets of the stack are blown in the horizontal direction, i. H. viewed across the width of the stack can be subjected to blowing air at several points or sections or continuously over a width corresponding to at least half the sheet width in the region of their front sheet edge.

During the operation of such a device, sheets of the stack are subjected to blowing air on their side pointing in the transport direction, viewed in the horizontal direction, by a blowing device at several points or sections or continuously over a width corresponding to at least half the sheet width.

Exemplary embodiments of the invention are shown in the drawing and are described in more detail below.

• 1 eine schematische Darstellung eines Anlegers und einer einem Druckwerk vorgeordneten Bogenanlage einer Bogendruckmaschine in Seitenansicht;
• 2 eine Schrägansicht einer ersten Ausführung für eine Blaseinrichtung;
• 3 eine Schrägansicht einer zweiten Ausführung für eine Blaseinrichtung.

Show it:

• 1 a schematic representation of a feeder and a printing unit upstream sheet feeder of a sheet-fed printing press in side view;
• 2 an oblique view of a first embodiment for a blowing device;
• 3 an oblique view of a second embodiment for a blowing device.

In 1 is, in part, a sheet-processing machine designed as a printing press, preferably as a sheet-fed printing press shown. In principle, however, you can also use another sheet-processing machine such as e.g. B. a punch, cutting, painting or other machine with the requirement of an input-side sheet separation can be formed.

The sheet-processing machine explained here using the example of a sheet-fed printing press comprises a feeder 01, e.g. B. sheet or pile feeder, a conveyor table 02, a sheet feeder 03 and, following the sheet feeder 03, one or more units 04, not shown here in detail, for treating and/or processing the sheets 06, as shown here, e.g. B. a printing unit 04, coating unit, drying unit, calendering unit or the like.

A stack 09, for example a stack of sheets 09, is placed on a stacking table 10 in feeder 01. The stacking table 10 can be adjusted in height with the aid of a lifting device 11 in order to raise the top sheet 06 of the stack of sheets 09 to a fixed or only slightly variable height, regardless of the number of sheets 06 in the stack 09, so that it is suitable for transferring the sheets 06 to the belt table 02 keep. In the representation of 1 if the sheets 06 of the stack 09 lie directly on the stacking table 10, but there could also be a pallet between the stack 09 and the stacking table 10, on which the stack 09 was transported to the stacking table 10 and placed on it and the height of which is not known that the position of the lifting device 11 cannot be used to determine the height of the stack 09 or the number of sheets 06 contained in the stack 09.

A front stop 16 defines a vertical plane in which the front edges of the sheets 06 of the sheet stack 09 are positioned. A curved flap 17 is fitted around a flap shaft 18 between the in 1 shown, which extends the front stop 16 in a straight line and can be pivoted counterclockwise into a substantially approximately horizontal position, in which it supports the transport of the sheets 06 to the downstream belt table 02.

The feeder 01 comprises various tools 12, combined here in a sheet separator 14; 13 for dividing the stack 09 into individual sheets 06 and for transporting the sheets 06 away to the printing units 04 and possibly other units of the sheet-fed printing press.

Among these tools 12; 13 include, on the one hand, a plurality of so-called suction cups 12, in particular tools 12 embodied as separating suction cups 12, in particular transport tools 12, which are arranged over a rear edge 05 of the stack 09 in the transport direction T of the sheets 06 and can be moved essentially in the vertical direction. The separating suckers 12 each comprise a suction cup made of flexible plastic which is open at the bottom towards the stack 09 and is connected at its upper end to a common vacuum source. The negative pressure must be sufficient to allow the suction cups to adhere securely to the sheet 06 to be lifted from the stack 09, but it must not be so strong that it draws the sheet 06 into the suction cup and deforms it as a result. If not all of the suction cups of the separating suction device 12 are in contact with a sheet 06 to be lifted, the air flow over an uncovered suction cup can result in the other suction cups not achieving the negative pressure required for lifting. For a safe lifting of a sheet 06, it is therefore important that all suction separators 12 come into contact with it at the same time. For this purpose, each suction separator 12 can be moved relative to the sheet separator 14 with the aid of its own drive, in particular a linear actuator; Preferably, a common frame, in which all suction separators 12 are held, can be moved relative to sheet separator 14 with the aid of a fast, powerful main actuator, in order to suck sheet 06 from stack 09 and lift it along trailing edge 05, and to smooth out any unevenness on the upper side of the sheet Stack 09 and to ensure simultaneous contact of all suction separators 12 with the sheet 06 to be lifted, the suction separators 12 can be adjusted relative to the frame with the aid of auxiliary actuators, with the latter being able to be slower and have a smaller stroke than the main actuator.

As a further tool 15 of the sheet separator 14, a tool 15 designed as a feeler foot 15 can be provided, which is located between an in 1 shown, along the rear edge 05 on the stack 09 pressing holding position and compared to the holding position raised and opposite to the transport direction T behind the edge 05 offset rest position. The feeler foot 15 is placed in the holding position when the top sheet 06 of the stack 09 has been lifted by the suction separators 12 along the rear edge 05, in order to prevent the underlying sheets 06 of the stack 09 from being whirled up if one behind the edge 05 blowing device 19 arranged at the level of the top of the stack 09 blows air into an open gap 07 between the lifted sheet 06 and the rest of the stack 09.

Furthermore, suction devices 13, in particular tools 13 designed as transport suction devices 13, in particular transport tools 13, are provided on the sheet separator 14, which execute a predominantly vertical movement in or against the transport direction T. Like the suction separators 12, the transport suckers 13 have flexible suction cups which, after the suction separators 12 have been lifted, are subjected to a vacuum in order to hold the sheet 06 raised to drag. At the same time, vacuum is no longer applied to suction separators 12, so that they release sheet 06. The air blown into gap 07 by blower device 19 lifts sheet 06 over its entire surface from stack 09 and forms an air cushion under sheet 06, on which sheet 06, driven by the horizontal movement of transport suckers 13, over which the the horizontal pivoted sheet flap 17 is pushed away onto the belt table 02.

The belt table 02 downstream of the feeder 01 is designed as a suction belt table 02 in the exemplary embodiment. It preferably comprises two rollers 20; 21, for example a drive roller 20 and a deflection roller 21. Between the two rollers 20; 21 extends a one-part or multi-part table plate 22. The table plate 22 forms the multiple perforated upper side of a suction box 23. The drive roller 20 and the deflection roller 21 are wrapped by at least one conveyor belt 24 which, like the table plate 22 over which it extends, is perforated many times, so that it is not sucked onto the table plate 22, but a sheet 06 is sucked onto the conveyor belt 24.

The circumferential speed of the conveyor belt 24 is generally lower than the ratio of the edge length of the sheets 06 to the cycle time of the sheet separator 14, so that when the transport suckers 13 begin to push a new sheet 06 over the sheet flap 17, the previous sheet 06 has not yet completely happened. A shingled flow of sheets 06 is thus formed on the conveyor belt 24, in which the number of sheets 06 overlapping one another is variable depending on the circulation speed, edge length and cycle time.

The sheet feeder 03, to which the sheets 06 are conveyed by the circulating conveyor belt 24, comprises a feed table 26 and, on a rear edge of the feed table 26 in the transport direction T, stops 27, which from their in 1 shown, blocking the conveying path of the sheets 06, can be lowered in order to clear the path for a sheet 06 resting against the stops 27 to the subsequent printing unit 04, from which in 1 a transfer drum 29, an impression cylinder 30 and a blanket cylinder 31 are shown.

In order to loosen any sheets 06 that may still be stuck at the leading edge, a preferred embodiment provides at least one blowing device 32, by means of which blowing air can be applied to sheets 06 lying preferably in a region near the top edge of the front side of the stack in the region of their leading sheet edge. A region of the stack 09 from the stack edge up to 200 mm, advantageously up to 100 mm, in particular up to 50 mm below the top stack edge to ?? to understand. Preferably, the sheets 06 lying directly on top can also be inflated. If air is blown into such an upper area, the stack 09 is loosened up in the area of the sheets 06 that are about to be removed, minimizing the risk of it settling and/or getting caught again. The sheets 06 can be peeled off without problems.

In particular, the blowing device 32 - preferably in the above Sheets 06 of the stack 09 located near the top edge of the front side of the stack, viewed in the horizontal direction, can be subjected to blowing air at several points or sections or continuously over a width corresponding to at least half the sheet width in the area of their front sheet edge.

In a particularly advantageous embodiment, sheets 06 of stack 09 - preferably located in the above-mentioned area near the top edge of the front of the stack - are viewed in the horizontal direction by blower unit 32 in the two lateral edge areas, for example within the two outer thirds, at least one point each or in at least one section can be charged with blown air (see e.g. 2 ).

In order to pressurize such sheets 06 lying in the region near the top edge, the blowing device 32 on the front side of the stack, i. H. one or more nozzles 33.1 on one side of the stack facing the first printing unit 04; 33.2; 33.3, e.g. B. as individual nozzles 33.1; 33.2; 33.3, or nozzle groups 34.1; 34.2; 34.3 from nozzles 33.1; 33.2; 33.3, for better differentiation from any further nozzles or nozzle groups that may be provided below as first nozzles 33.1; 33.2; 33.3 or first nozzle groups 34.1; 34.2; 34.3, through which the sheets 06 in the area near the upper edge of the front side of the stack, i. H. several of the uppermost sheets 06 can be subjected to blowing air in the area of their front sheet edge.

Preferably, at least one first nozzle 33.1; 33.2 or first nozzle group 34.1; 34.2 provided in the two outer thirds of the sheet width (see e.g. 2 ). The sheets 06 can thus be fanned out from the sides. In addition to this, a further first nozzle 33.3 or nozzle group 34.3 can also be provided in an area in between, which is particularly advantageous for larger-format sheets 06. This can be spaced apart or directly adjacent to the adjacent first nozzles 33.1; 33.2 or nozzle groups 34.1; 34.2 can be arranged.

The one or more first nozzles 33.1; 33.2; 33.3 or nozzle groups 34.1; 34.2; 34.3 are preferably arranged under the curved flap 17 and aligned in their beam angle in such a way that they are directed towards the above-mentioned area near the upper edge.

In the preferred embodiment shown here, two nozzle groups 34.1; 34.2, in particular blower tubes 34.1; 34.2 provided in the two edge areas of the stack 09 and on the above mentioned directed towards the upper edge. Between these, an unblown gap or, in an advantageous development—especially for larger formats—parallel to the front top edge of the stack and preferably running in the same alignment, one or more further nozzle groups 34.3, in particular blowing tubes 34.3, can be provided.

In production operation, the stack 09 is through these first nozzles 33.1; 33.2; 33.3 or nozzle groups 34.1; 34.2; 34.3 in the above way in several places or on a significant width and/or in the above mentioned Blow near the upper edge area while z. B. the stack 09 is reduced in height by removing the sheets 06 and the stack 09 is vertically tracked to maintain the position of the top sheet 06 in each case. As a result, all of the sheets 06 to be delivered gradually reach the above-mentioned Effective range of the first nozzles 33.1; 33.2; 33.3 or nozzle groups 34.1; 34.2; 34.3 before passing through the tools 12; 13 of the sheet separator 14 are added and conveyed away.

As an alternative to the above Blowing air on the stack 09 in the region of the top edge to loosen the sheets 06 or, preferably, in addition to this, in a particularly advantageous embodiment or development, the blowing device 32 is designed to blow a sheet 06 leaving the stack 09 on its transport path at an angle with at least one vertical component to apply blown air from below. As a result, the sheet 06 is supported from below on the way downstream of the stack 09 and is thus protected from buckling and getting caught.

In particular, sheets 06 or their transport path are supported by blower unit 32, viewed in the horizontal direction, at a number of points or sections or continuously at a width corresponding to at least half the sheet width in the above-mentioned Way from below with blast air can be applied. In the case of section-by-section loading, an inclined position or a cross-sectional profile progression in the arc width can be corrected if necessary.

In order to impinge on the sheets 06 leaving the stack 09, the blowing device 32 on the front side of the stack, i. H. one side of the stack facing the first printing unit 04, one or more nozzles 36.1; 36.2; 36.3 or nozzle groups 37.1; 37.2; 37.3 from nozzles 36.1; 36.2; 36.3, for better differentiation in the following as second nozzles 36.1; 36.2; 36.3 or nozzle groups 37.1; 37.2; 37.3, through which the sheets 06 leaving the stack 09 or the relevant transport path in the above sense can be or is subjected to blowing air from below.

The one or more second nozzles 36.1; 36.2; 36.3 or nozzle groups 37.1; 37.2; 37.3 are preferably below the sheet flap 17, but preferably downstream with respect to the transport direction T and/or above the one or more first nozzles 33.1; 33.2; 33.3 or nozzle groups 34.1; 34.2; 34.3 and aligned in their jet angle in such a way that they are directed from below against the sheets 06 leaving the stack 09 or their transport path.

In the embodiment preferred here, one or more nozzle groups 37.1; 37.2; 37.3, in particular blower tubes 37.1; 37.2; 37.3 provided and onto the sheets 06 or the above mentioned sheet leaving the stack 09. Transport path directed.

A above nozzle group 34.1; 34.2; 34.3; 37.1; 37.2; 37.3 can through a series of closely adjacent nozzles 33.1; 33.2; 33.3; 36.1; 36.2; 36.3 or blowing openings 33.1; 33.2; 33.3; 36.1; 36.2; 36.3 of a so-called blowpipe 34.1; 34.2; 34.3; 37.1; 37.2; 37.3 be formed. A nozzle group 34.1; 34.2; 34.3; 37.1; 37.2; 37.3 can also have several such rows of nozzles 33.1; 33.2; 33.3; 36.1; 36.2; 36.3 or blowing openings 33.1; 33.2; 33.3; 36.1; 36.2; 36.3 include. In principle, all of the individual nozzles 33.1; 33.2; 33.3; 36.1; 36.2; 36.3 provided, i. H. nozzles 33.1 not comprised by a group; 33.2; 33.3; 36.1; 36.2; 36.3 or all nozzle groups 34.1; 34.2; 34.3; 37.1; 37.2; 37.3 or at least the individual nozzles 33.1; 33.2; 33.3; 36.1; 36.2; 36.3 or nozzle groups 34.1; 34.2; 34.3; 37.1; 37.2; 37.3 of the same type, namely those for loosening and those for supporting, supplied by the same supply and optionally switchable via a pneumatic valve and/or variable in blowing strength. Preferably, several or all of the individual nozzles 33.1; 33.2; 33.3; 36.1; 36.2; 36.3 or nozzle groups 34.1; 34.2; 34.3; 37.1; 37.2; 37.3 can be switched individually via pneumatic valves (not shown) and/or can be varied in terms of their blowing strength.

As individual nozzles 33.1; 33.2; 33.3; 36.1; 36.2; 36.3 are here in contrast to jointly supplied nozzle groups 34.1; 34.2; 34.3; 37.1; 37.2; 37.3 individual components with e.g. B. called its own connector, as opposed to blown air openings 33.1; 33.2; 33.3; 36.1; 36.2; 36.3 of a blowing tube 34.1; 34.2; 34.3; 37.1; 37.2; 37.3 or a row of nozzles 33.1 arranged on a common supply line; 33.2; 33.3; 36.1; 36.2; 36.3 a distance of z. B. more than 50 mm, in particular more than 100 mm to each other.

The first nozzles 33.1; 33.2; 33.3 or nozzle groups 34.1; 34.2; 34.3 operated continuously during production, while the second nozzles 36.1; 36.2; 36.3 or nozzle groups 37.1; 37.2; 37.3 are preferably operated in synchronism with the sheet feed in such a way that they are active at least in a time interval that includes the point in time at which the sheet 06 arrives with its leading sheet edge on the transport path at the height of the sheet flapper 17 and/or a first roller 20 downstream. In a subsequent time interval, blowing is or will be temporarily suspended until blowing takes place again in the corresponding first interval for the next sheet 06. This helps to save compressed air and/or to avoid unnecessary forces on the sheet 06.

Reference List

01

investor

02

Belt table, suction belt table

03

arch system

04

work, printing work

05

edge, rear

06

bow

07

gap

08

-

09

Stack, stack of sheets

10

stacking table

11

lifting device

12

Tool, transport tool, suction cup, separating suction cup

13

Tool, transport tool, suction cup, transport suction cup

14

sheet separator

15

tool, tracer foot

16

front stop

17

bow flap

18

flap shaft

19

blowing device

20

roller, drive roller

21

roller, deflection roller

22

table sheet

23

suction box

24

conveyor belt

25

-

26

feeding table

27

attack

28

-

29

false drum

30

Impression cylinder

31

blanket cylinder

32

blowing device

33.1

Nozzle, blow port, single nozzle, first

33.2

Nozzle, blow port, single nozzle, first

33.3

Nozzle, blow port, single nozzle, first

34.1

Nozzle group, first, blowpipe

34.1

Nozzle group, first, blowpipe

34.1

Nozzle group, first, blowpipe

35

-

36.1

Nozzle, blow port, single nozzle, second

36.2

Nozzle, blow port, single nozzle, second

36.3

Nozzle, blow port, single nozzle, second

37.1

Nozzle group, second, blowpipe

37.2

Nozzle group, second, blowpipe

37.3

Nozzle group, second, blowpipe

T

transport direction

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 19745301 A1 [0003]

Claims (13)

Feeder (01) of a sheet (06) treating or processing machine, in which a stack (09) of sheets (06) to be processed can be accommodated, and at least one transport tool (13) through which an uppermost sheet (06) of an im feeder (01) can be transported in a transport direction (T) away from the stack (09) into a downstream transport path, characterized in that a blowing device (32) is provided on the downstream side of the stack (09). through which sheets (06) of the stack (09), viewed in the horizontal direction, can be subjected to blowing air at several points or sections or continuously over a width corresponding to at least half the sheet width in the region of their front sheet edge. investors after claim 1 , characterized in that the blowing device (32) can apply blowing air to sheets (06) which are located in a region of the stack (09) from the stack edge to a maximum of 200 mm below the stack edge. investors after claim 1 or 2 , characterized in that the sheets (06) can be acted upon by the blowing device (32), viewed in the horizontal direction, at least in the two lateral edge regions of the sheet edge with blowing air. investors after claim 1 , 2 or 3 , characterized in that the blowing device (32) for impinging on the sheets (06) in the stack (09) comprises one or more first nozzles (33.1; 33.2; 33.3) or one or more first nozzle groups (34.1; 34.2; 34.3). which the sheets (06) can be subjected to blowing air in the area of their front sheet edge. investors after claim 4 , characterized in that two groups of nozzles (34.1; 34.2) running horizontally and/or parallel to the edge of the stack are provided in the two edge regions of the stack (09) and are directed towards the above-mentioned region near the top edge. investors after claim 1 , 2 , 3 , 4 or 5 , characterized in that the blowing device (32) is also designed to apply blowing air from below to a sheet (06) leaving the stack (09) on its transport path at an angle with at least one vertical component. investors after claim 6 , characterized in that the sheets (06) or their transport path, viewed in the horizontal direction, can be or is subjected to blowing air from below by the blowing device (32) at several points or sections or continuously over a width corresponding to at least half the sheet width. investors after claim 6 or 7 , characterized in that the blowing device (32) comprises one or more second nozzles (36.1; 36.2; 36.3) or nozzle groups (37.1; 37.2; 37.3) of second nozzles (36.1; 36.2; 36.3) through which the stack (09) leaving sheet (06) or whose transport path can be acted upon with blown air from below investors after claim 4 , 5 or 8th , characterized in that several or all of the nozzles (33.1; 33.2; 33.3; 36.1; 36.2; 36.3) or the nozzle groups (34.1; 34.2; 34.3; 37.1 ; 37.2; 37.3) can be switched individually via pneumatic valves and/or their blowing intensity can be varied. Method for supporting the sheet separation in a feeder (01) of a sheet (06) processing machine, in particular using a device according to one of Claims 1 until 9 , wherein the sheets (06) on top of a stack (09) are successively transported away from the stack (09) by at least one transport tool (13) into a transport path that follows downstream, characterized in that sheets (06) of the stack (09) on its side pointing in the transport direction (T) viewed in the horizontal direction by a blowing device (32) at several points or sections or continuously over a width corresponding to at least half the sheet width with blowing air. procedure after claim 10 , characterized in that the sheets (06) are subjected to blowing air by the blowing device (32), viewed in the horizontal direction, at least in the two lateral edge regions of the sheet edge. procedure after claim 10 or 11 , characterized in that the blowing device (32) also applies blowing air to sheets (06) leaving the stack (09) on its transport path at an angle with at least one vertical component. procedure after claim 12 , characterized in that the loading of the sheets (06) is clocked to the sheet feed in such a way that loading in a Time interval takes place, which includes the point in time at which the sheet (06) arrives with its leading sheet edge on the transport path at the level of a downstream sheet flap (17) or a downstream first roller (20).

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