EP1106551A2 - Apparatus and method for cutting a web - Google Patents

Abstract

The cutter consists of a number of straight cutter elements (3a,b,c,d.13a,b,c,d.) for cutting the web of material (1) into signatures (7). Gripper elements (4a,b,c,d..14a,b,c,d..) cooperate with the cutter elements The cutter elements are moved along a first and second path (105,106) between which is the signature cutting part (1000).

Description

The present invention relates to a device for cutting a web according to the The preamble of claim 1 and a method for cutting a web according to the Preamble of claim 12.

Web-fed rotary printing machines print on a continuous material web, e.g. a Paper web. The continuous web is printed in a cutter in Signatures cut, which are then folded in a folder or on different types are arranged or collected. To signatures in one to arrange the desired type, or to enable desired folding operations, the Signatures e.g. branched into two streams and also braked. To the To reduce signature length often has to be the ratio of angular velocity be enlarged between the folder and the printing units of the printing press. Therefore, the speed of the signature after being cut off the web was increased, which adversely affects downstream transport functions affects. Signatures therefore often have to be braked in a braking device, which but often damage the signatures, e.g. by making donkey ears or that Clog the folder because the transport from or to the braking device does not works.

In the U.S. 5.865.082 is a device for cutting signatures from one Material web described. A pair of rotating cylinders cut the web in signatures. The web is, as it is passed between the two cutting cylinders, held by a large number of conveying elements that move in two circular paths. The conveyor elements hold the signatures while they are being cut. This The disadvantage of the device is that the cutting cylinders only rotate, so that the Angular speed of the folder must be increased to increase the signature length shorten.

The U.S. 5,740,900 describes a device for dividing a product stream into a current A and a current B. The signatures are captured by grippers, where alternate grippers rotate to divide the product flow. A cutter is not explained.

It is the object of the present invention a reliable device for Cutting a web into signatures, the device being the cutting of Allows formats with variable section length.

This object is achieved by the features of claim 1. Further Features of the invention are contained in the dependent subclaims.

The present invention provides an apparatus for cutting a web of material is moved at a web speed in a web direction. The device has a plurality of cutting elements which can be moved in a straight line in the web direction for Cutting the web into signatures and a variety of gripper elements that work with the Interact cutting elements.

Since the cutting elements can be moved in a straight line in the direction of the web, the distance can used between the elements to set the signature length. The The speed of the web in the folder advantageously does not have to be changed to set the signature length.

Each gripper element can comprise a gripper that grips the signature and on Wish brakes. Each cutting element can comprise a knife and each Gripper element can comprise a groove against which the knife can cut the web. Each gripper element can also have a retractable, laterally, i.e. across to Transport direction, include running pin. The device can also be a Include brake disc that cooperates with the pin so that the gripper elements are supported and braked by the brake disc.

The device may include a drive mechanism that drives the cutting elements in Path direction moved. The drive mechanism can e.g. Linear motors include wherein the guide rails of the cutting elements are used as a stator and the Cutting elements, or also the gripper elements, the moving parts of the linear motor form.

The present invention also provides an apparatus for cutting a Material web, which has a large number of linearly movable first cutting elements which are movable along a first path, a plurality of rectilinear movable first gripper elements, which are movable along the first path, a A plurality of rectilinear movable second cutting elements which run along a second path are movable and cooperate with the first gripper elements, and a plurality of second gripper elements that are movable along the second path and interact with the first gripper elements. The train moves between the first and the second path through a signature cutting area.

The first cutting elements and the first gripper elements are preferred arranged alternately along the first path. After the Have passed the signature cutting area, the first gripper elements can become one move in the opposite direction to the second gripper elements so that the Signatures can be divided into two streams.

The first path and the second path are preferably two closed circular paths.

The cutting elements preferably comprise a laterally movable knife with two Blade that cuts a strip of material between the individual signatures or separates. This type of knife has an advantageous effect on the production of Printed products, because a knife with only one blade possible defects in the cut or cannot remove when printing, which results in color from a signature in the Border area of the next signature can appear. The strip of material used in the Using a knife with two blades arises, these shortcomings can be more beneficial Eliminate wise. The device can also be an air nozzle and / or Include suction device with which the strip of material from the groove into which the Strips after cutting, can be removed.

It is also an object of the present invention to provide a method for cutting a web to create, which allows the web to be cut reliably and it also enables signatures of variable section length to be produced.

This object is achieved by the features of claim 12. Further features of the invention are contained in the dependent subclaims.

A variety of cutting elements become straight in the signature cutting area moves, with the cutting elements moving in the web direction. "Movable in a straight line" means here that the elements at least in sections on an essentially straight path are movable, in contrast to circularly movable Elements, as is the case with conventional cutting cylinders. The train comes with cut the plurality of cutting elements into a stream of signatures, with each other the signature length changes depending on the controllable distance between the Cutting elements in the signature cutting area.

The method can also alternate branching of the signatures to obtain a first and a second stream of signatures.

The cutting elements are at web speed in the signature cutting area movable.

The method further sees a braking of the signatures after leaving the Signature cutting area and accelerating the cutting elements before entering the signature cutting area, if this is advantageous for cross cutting the web Way contributes.

The method preferably involves cutting a strip of material between every single signature. This cutting step can e.g. from a laterally rotatable Knives are executed, which can have two blades. The strip can then e.g. be removed by means of a blower or suction device. By a streak between the signatures, the quality in the marginal areas of the Signatures are improved.

The invention is more preferred below with reference to the drawings Embodiments described.

Fig. 1

zeigt eine schematische Seitenansicht eines erfindungsgemäßen Falzapparats;

Fig. 2

zeigt eine genauere Darstellung der Schneid- und Greiferelemente des Falzapparats nach Fig. 1;

Fig. 3

zeigt eine perspektivische schematische Seitenansicht des Falzapparats nach Fig. 1;

Fig. 4

zeigt eine genaue Ansicht der in Fig. 3 dargestellten Bremsscheibe;

Fig. 5

zeigt ein seitlich drehbares Messer nach einer weiteren erfindungsgemäßen Ausführungsform.

The drawings show:

Fig. 1

shows a schematic side view of a folder according to the invention;

Fig. 2

shows a more detailed representation of the cutting and gripper elements of the folder according to Fig. 1;

Fig. 3

shows a perspective schematic side view of the folder according to Fig. 1;

Fig. 4

shows a detailed view of the brake disc shown in Fig. 3;

Fig. 5

shows a laterally rotatable knife according to another embodiment of the invention.

Fig. 1 shows a folder 100 with a first circular path 101 and a second Circular path 102. A first circular path 101 comprises a first path 105 along which a variety of cutting elements 3a, 3b, 3c, 3d etc. and a variety of Gripper elements 4a, 4b, 4c, 4d etc are moved. The cutting elements and Gripper elements are arranged alternately along the path 105. The second circular path 102 also includes a plurality of cutting elements 13a, 13b, 13c, 13d etc. and one Plurality of gripper elements 14a, 14b, 14c, 14d etc. that run along a second path 106 be moved.

A material web, for example made of paper, enters a gap which is formed between circular path 101 and circular path 102. A ^" web" as defined here can comprise one or more material web strands, which can already be folded lengthways. Each cutting element can comprise a strut and a knife. Each gripper element can comprise a gripper and a groove. The web 1 is gripped between the strut of the cutting element 3b and the anvil of the gripper element 14b when the cutting element 3b comes together on the first path 105 and the gripper element 14b on the second path 106. The cutting elements and the gripper elements can lie on this section of the circular paths 101 and 102 , which is shown in FIG. 1 as signature cutting area 1000, move at the path speed.

As the web passes the signature cutting area 1000, it becomes between the strut and the anvil and the knife of the cutting element cuts the web 1, to create a variety of signatures. A knife in cutting element 13b cuts e.g. a web 1 against the anvil of the gripper element 4b. So a signature 7 created. A leading edge of the signature cut by cutting element 3c is gripped by the gripper of the gripper element 14c.

Since the gripper elements and the cutting elements of the circular paths 101 and 102 alternate, the signatures are divided into two streams when the gripper elements Leave cutting area, leaving a first stream 11a of signatures and a second Stream 10a are formed by signatures. These signatures can then be obtained from the Gripper elements are conveyed to the conveyor elements 10 and 11. The streams 11a and 10a can then leave the signature cutting area by the Gripper elements are braked so that the speed of the currents is approximately 20 percent the web speed is.

Because the cutting elements and the gripper elements are controlled in the Signature cutting area can occur, the signature length can be changed be that the distance between successive pairs of cutting and Gripper elements in the signature cutting area is controlled. So the present creates Invention a variable signature length (cut-to-cut distance), which in Fig. 1 as variable length L is shown.

2 shows a more detailed view of the signature cutting area 1000. The gripper element 14b comprises an anvil 20 and a rotatable gripper 21. The cutting element 3b comprises a knife 22 which e.g. is held by the support 23. The knife 22 can Cut web 1 while knife 22 and anvil 20 meet. Alternatively, web 1 can first be between the anvil 20 and the strut 24 of the Cutting elements 3b are held and then knife 22 is moved around the web 1 to cut. The cutting front edge of the web can then be removed from the rotating gripper are gripped, as shown on the further gripper element 4b, the one gripper 21 includes. The knife of cutting element 13b is not shown to figure to make it clearer, but it corresponds to the knife of cutting element 3b.

The gripper 21b presses the entire length of the front edge against the anvil 20b, damage to the leading edge, e.g. "Donkey ears" can be avoided. The The trailing edge 28 of the preceding signature is additionally removed from the gripper 21b Cut line pushed away. In contrast to most other folders without Needles must speed up the cut signatures with this procedure to create a space between the trailing edge of the preceding and the To create the leading edge of the subsequent signature.

The knife can be a laterally movable rotating knife or a scissor-like one Be knife.

5 shows a cutting element 113 for use with the device of FIGS. 1 and 2. The cutting element 113 comprises a frame 114 which e.g. by an engine or a Gear can be moved in the web direction and counter to the web direction, like that Arrows 115 and 116 show. The frame 114 supports the rotatable knife axis 112 on which a knife 111 is arranged. Knife 111 comprises two blades that are slightly offset, e.g. with a gap of 2 mm or less.

The cutting process with this knife proceeds as follows: The web is first between an anvil 110 and a support (not shown) that is defined by frames 114 extends above and / or below the knife 111, clamped. While the train passes the signature cutting area, the frame and the knife move with the two blades 111 toward 115 or 116 to make a pair of parallel cuts through the web produce. A very thin strip of cutting residue lies in groove 109 of the anvil 110.

This small strip of cutting residue can be through an air nozzle 108 or a suction system 107 be removed, as shown in Fig. 1.

Fig. 3 shows how the cutting element / gripper element pairs are controlled so that they be accelerated when they enter the signature cutting area and are braked when they leave the signature cutting area. Every cutting element and every Gripper element includes a retractable pin 15. When a series of cutting and Gripper elements passes a ramp 17, the pins 15 are in the elements pushed back. A spring in the elements pushes the pin out again as soon as that Element leaves the ramp so that it is guided into a groove in a disc 16. The Movement of the elements is then from the disc 16 and a guide rail 18th controlled. While the disc 16 rotates counterclockwise, the Restriction of movement that emanates from rail 18, pin 15 to the outer edge of the Disc 16. As the effective radius increases, the elements are accelerated. If the pins leave the grooves of the disc 16, the movement of the elements by a drive mechanism 120, e.g. a belt drive, controlled. For the second Path 106 provides similar disks as well as a drive mechanism Drive mechanism 120 can be provided.

The drive mechanism 120 stops the speed of the clamp strut Web speed. The speed of rotation of the disc 16 in relation to that Path speed sets the distance between the successive pairs of Gripper and cutting elements that determine the section length of the signatures. By comparing the relative speed of the disc with that Web speed (print speed) changed, the printer can change the cut-to-cut length of signatures change.

The drive mechanism 120 transfers control of the clamp strut to one Brake disc 19. The brake disc 19 corresponds to the disc 16, except that the disc 19 is modified so that it releases the pins 15 when the pins the minimum Approach the radius of the groove in disc 19. The gripper elements are on the desired one Signature delivery speed slowed down because of its movement from the guide rail 18 is controlled, which guides the gripper elements so that your pins are constantly on the center of the Brake disc 19 close.

FIG. 4 shows a more detailed view of the brake disc 19, which is shown in FIG. 3. Fig. 4 shows how the grooves 119 are chamfered towards the center of the brake disc 19, so that the Pin while being controlled from guide rail 18 to the center of brake disc 19 too moved, is pressed into a gripper or cutting element. If the pin 15 from the Brake disc 19 is removed, the control of the clamping strut to another Hand drive mechanism 121, which has the same speed as that ready gripper or cutting elements.

As an alternative to the mechanical drive shown in FIG. 3, the Linear motor technology can be used. In this case, guide rails that can form paths 105 and 106 to the stator of the linear motor. This Guide rails have magnetic coils. The size of the coils can vary or that Current in the coils can be changed to accelerate or brake the To effect cutting and gripper elements. Therefore determine and control the structure of the Coils in the stator and the control of the current frequency in the coils the movement and the distance between the gripper and cutting elements, which the moving parts of the Form linear motor. The gripper and cutting elements have magnets that pass through powered the current in the electrical coils, i.e. towards the guide rail be moved.

Print speed signals and printer inputs that indicate the desired cut-to-cut length relate to the control of the linear motor, e.g. by a PLC (programmable logic controller), i.e. a programmable Control device. Depending on the type of linear motor, precise position control can be used the clamping struts require the use of position sensors that indicate the current position of the Report moving gripper or cutting elements to the position control.

The term "gripper element" as used in the description does not have to be Grippers include, but can only be used as an anvil for each Cutting element act.

List of reference numbers

1

train

3a, 3b, 3c, 3d etc.

Cutting elements

4a, 4b, 4c, 4d etc.

Gripper elements

7

signature

10th

Funding elements

10a

second stream

11

Funding elements

lla

first stream

13 a, 13b, 13c, 13d etc.

Cutting elements

14a, 14b, 14c, 14d etc.

Gripper elements

15

pen

16

disc

17th

ramp

18th

Guide rail

19th

Brake disc

20th

anvil

20b

anvil

21

rotating gripper

21b

rotating gripper

22

knife

23

support

24th

strut

28

Trailing edge

100

Folder

101

Circular path

102

Circular path

105

first path

106

second path

107

Suction system

108

Air nozzle / air jet

109

Groove

110

anvil

111

knife

112

Knife axis

113

Cutting element

114

frame

115

arrow

116

arrow

119

Groove

120

Drive mechanism

121

Drive mechanism

1000

Signature cutting area

L

variable length

Claims (19)

Device for cutting a web (1) which is moved at a web speed in the web direction,
marked by
a large number of straight-line cutting elements (3a, 3b, 3c, 3d etc., 13a, 13b, 13c, 13d etc.) movable in the web direction for cutting the web (1) into signatures (7) and a large number of gripper elements (4a, 4b, 4c, 4d etc., 14a, 14b, 14c, 14d etc.), which interact with the cutting elements (3a, 3b, 3c, 3d etc., 13a, 13b, 13c, 13d etc.). Device according to claim 1,
characterized by
that each gripper element (4a, 4b, 4c, 4d etc., 14a, 14b, 14c, 14d etc.) comprises a gripper (21, 21b). Device according to claim 1 or 2,
characterized by
that each cutting element (3a, 3b, 3c, 3d etc., 13a, 13b, 13c, 13d etc.) comprises a knife (22). Device according to one of the preceding claims,
characterized by
that each gripper element (4a, 4b, 4c, 4d etc., 14a, 14b, 14c, 14d etc.) comprises an anvil (110). Device according to one of the preceding claims,
characterized by
that each cutting element (3a, 3b, 3c, 3d etc., 13a, 13b, 13c, 13d etc.) comprises a laterally movable knife (22) with two blades. Device according to one of the preceding claims,
characterized by
that each gripper element (4a, 4b, 4c, 4d etc., 14a, 14b, 14c, 14d etc.) comprises a pin (15) and a brake disc (19) which cooperates with the pin (15). Device according to one of the preceding claims
marked by
a drive mechanism (120) which moves the cutting elements (3a, 3b, 3c, 3d etc., 13a, 13b, 13c, 13d etc.) in the web direction. Device for cutting a web (1) according to one of the preceding claims
marked by a plurality of first cutting elements (3a, 3b, 3c, 3d etc.) which can be moved in a straight line and which can be moved along a first path (105), a plurality of first gripper elements (4a, 4b, 4c, 4d etc.) which can be moved in a straight line and are movable along the first path (105), a plurality of linearly movable second cutting elements (13a, 13b, 13c, 13d etc.) which are movable along a second path (106) and which interact with the first gripper elements (4a, 4b, 4c, 4d etc.), a plurality of second gripper elements (14a, 14b, 14c, 14d etc.) which move along the second path (106) and interact with the first cutting elements (3a, 3b, 3c, 3d, etc.), wherein the web (1) moves between the first path (105) and the second path (106) through a signature cutting area (1000). Device according to claim 8,
characterized by
that the first cutting elements (3a, 3b, 3c, 3d etc.) and the first gripper elements (4a, 4b, 4c, 4d etc.) are arranged alternately along the first path (105). Device according to claim 8 or 9,
characterized by
that the first gripper elements (4a, 4b, 4c, 4d etc.) move in an opposite direction to the second gripper elements (14a, 14b, 14c, 14d etc.) after they have passed the signature cutting area (1000). Device according to one of claims 8 to 10,
characterized by
that the first path (105) is a circular path (101) and / or that the second path (106) is a circular path (102). Method for cutting a web (1), the web (1) moving in a signature cutting area (1000) in a web direction,
marked by
the following process steps: Straight movement of a plurality of cutting elements (3a, 3b, 3c, 3d etc., 13a, 13b, 13c, 13d etc.) in the web direction in the signature cutting area (1000); Cutting the web (1) with the plurality of cutting elements (3a, 3b, 3c, 3d etc., 13a, 13b, 13c, 13d etc.) to produce signatures (7); Grasping the signatures (7); and Changing the length of the signatures (7) by controlling the distances between the cutting elements (3a, 3b, 3c, 3d etc., 13a, 13b, 13c, 13d etc.) in the signature cutting area (1000). Method according to claim 12,
marked by
alternately branching the signatures (7) to obtain a first stream (11a) and a second stream (10a) of signatures. A method according to claim 12 or 13,
marked by
Moving the web (1) at a web speed and moving the cutting elements (3a, 3b, 3c, 3d etc., 13a, 13b, 13c, 13d etc.) at the web speed in the signature cutting area (1000). Method according to one of the preceding claims 12 to 14
marked by
Braking the signatures (7) after leaving the signature cutting area (1000). Method according to one of claims 12 to 15,
marked by
Accelerate the cutting elements (3a, 3b, 3c, 3d etc., 13a, 13b, 13c, 13d etc.) before entering the signature cutting area (1000). Method according to one of claims 12 to 16,
marked by
Cutting a thin strip of material from the web (1) when cutting the web (1) with a knife (22) with two blades. Method according to one of claims 12-17,
characterized
that the linear movement is carried out with the help of a linear motor. Web rotary printing machine,
marked by
a device according to one of claims 1 to 11.

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