EP1116560B1 - Cutting device with adjustable cutting lenght - Google Patents

Description

The present invention relates to a variable section length cutting device for cutting a web strand into signatures of desired length, particularly in a folder of a web-fed rotary printing press, according to the preamble of claim 1.

Such a cutting device is for example from the CH - 250 235 known.

Web-fed rotary printing presses usually have a printing unit downstream folding. The folder cuts and folds a paper web or web strand to make a signature or sheet of a particular length.

Known folding machines with variable section length are usually divided into two categories. In the first category, the size or length of the signatures is changed by replacing parts of the folder, such as the folder. the collecting cylinder, the knife cylinder or the jaw cylinder to be replaced. This solution has the disadvantage that it is costly and time consuming, since it takes considerable time to replace individual parts of the folder.

In the second category of variable section length folders, the angular velocity of the knife cylinder is increased relative to the speed of the web, thereby accelerating the signature to bring the leading edge of the signature to the desired position on a transfer cylinder. The disadvantage of this technique is the difference in the speed of the knife cylinder to that of the web track. In this technique, the peripheral speed of the knife cylinder must be equal to or higher than the speed of the web strand. However, if the peripheral speed of the knife cylinder is significantly higher than the speed of the web strand to achieve the shortest possible signature length, the quality of the cut decreases.

The transport speed of the signatures after the cut corresponds to the peripheral speed of the knife cylinder. When the peripheral speed of the Increasing the knife cylinder relative to the speed of the web strand, the speed of the signatures must also be increased in proportion to the speed of the web strand. This requires the signatures to be accelerated to a new, higher speed. The acceleration of the signatures can cause the position of the signatures to change. This change in the position of the signatures can lead to a deterioration in the quality of the signatures and the performance of the cutting system and thus reduce the performance of the entire folder.

An adjustable folder for web-fed rotary presses is in the GB 1,214,339 described. The variable folder is equipped with a knife cylinder which cooperates with a transfer cylinder. Between the knife cylinder and the transfer cylinder, a gap is formed through which the web is passed. The transfer cylinder carries around its circumference train detecting elements each comprising a gripper for detecting the leading edge of a web leaving the nip, a folding blade cooperating with a jaw in a third cylinder and a support surface cooperating with the associated knife of the knife cylinder. The angular position of the gripper and the folding blade are adjustable on the axis of rotation of the transfer cylinder in relation to the angular position of the support surface in order to change the sheet size can.

The DE 39 34 673 C2 describes a length-adjustable cross-cutting device for moving webs. A web runs between a knife cylinder and an associated cylinder of the same diameter. The knife cylinder is equipped with cutting blades on its periphery. The associated cylinder carries elastic cutting strips, which interact with the cutting blades on the knife cylinder for cutting the web. The cutting blades and the cutting bars are pivotally mounted about pivot axes. The pivot axes are located in the cylinders and are arranged parallel to the cylinder axes. During a cutting operation, the cutting blades and the cutting bars are pivoted in such a way that they move in the opposite direction of the web running direction. A disadvantage of in the DE 39 34 673 C2 described in the format length adjustable cross cutting device This is because a rather complicated pivoting mechanism is needed because the movement of the cutting blades and the cutting bars must be synchronized with each cutting operation.

An article entitled "Goss Exhibits Futuristic Concept Press" by Gerry Valerio, describes the use of a removable, seamless sheath of a knife cylinder by means of which a variable section length can be achieved. The section length is changed by removing a shroud from the knife cylinder and attaching another thicker or thinner shroud. To compensate for the changes in the diameter of the cylinder, the position of the cylinder to each other must also be aligned. A disadvantage of using interchangeable sheaths is that a different sheathing is needed for each desired section length.

It is an object of the present invention to provide a cutting device for cutting a web strand into signatures of desired length, which obviates the above drawbacks of previously known devices of this type and enables the cutting of signatures of different length without adapting the working speed of the device must and without having to replace parts of the device.

In particular, it is an object of the present invention to provide a variable section length folder which permits cutting of different signature lengths, the transfer cylinder of the device being in control of the leading edge of the signature without having to adjust the speed of the transfer cylinder and without that parts of the device must be replaced.

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

A variable section length cutting device according to the invention comprises a knife cylinder and a transfer cylinder having a central axis and a periphery adapted to cooperate with the knife cylinder to cut a web strand into signatures of desired length.

The transfer cylinder has at its periphery a portion of variable diameter, hereinafter also referred to as adjustable or variable diameter portion, wherein the adjustable diameter portion connected to the transfer cylinder, and is arranged on this and is movable in the direction of the cylinder center axis to and from the cylinder center axis to set the desired length of the signatures.

The cutting device according to the invention has the advantage that it can be easily adjusted to different signature lengths, without having to replace parts of the cutting device.

According to the invention, the adjustable diameter section is an adjustable roller, e.g. with a diameter in the range between 5 and 20 cm, which is movable in the direction of the cylinder center axis to and from the cylinder center axis.

According to a further feature of the invention, a lifting and lowering device, e.g. a pneumatic cylinder, a winch, e.g. a linear winch and / or an eccentric winch, or also a rack-based lifting and lowering mechanism mounted by means of which the adjustable diameter portion can be moved to the cylinder center axis to and from the cylinder center axis.

In accordance with a further feature of the invention, a gripper and a folding blade are connected at the periphery of the transfer cylinder at a predetermined distance from the cylinder center axis with the transfer cylinder, wherein the adjustable Diameter section between the gripper and the folding blade is arranged. This has the advantage that the knife cylinder with respect to the transfer cylinder can remain in a predetermined position, even if the adjustable diameter portion is moved to the center of the transfer cylinder to or away from him.

According to a further embodiment of the invention, a cutting blade is arranged on the knife cylinder, which cooperates with a arranged on the periphery of the transfer cylinder cutting bar and cuts the web into signatures when the knife cylinder and the transfer cylinder rotate synchronously to each other.

In accordance with an additional feature of the invention, the transfer cylinder has a constant angular velocity, which results in the advantage that a complicated control of the rotational speed of the transfer cylinder is not necessary.

According to a further embodiment of the invention, in each case a gripper and a cutting bar are connected to the adjustable diameter section. The gripper and the cutting bar are preferably movable together with the adjustable diameter portion on the cylinder center axis and away from it.

A folding section according to the invention with a variable section length comprises a knife cylinder and a transfer cylinder which is designed in such a way and cooperates with the knife cylinder that a web strand guided on it is cut into signatures of the desired length. The transfer cylinder has a cylinder center axis and a periphery and has an adjustable diameter portion, which is preferably arranged at the periphery of the transfer cylinder. The variable diameter portion is preferably connected to the transfer cylinder and is movable toward and away from the cylinder center axis to set a desired portion length of the signatures. The folder according to the invention further comprises a jaw cylinder, a Cylinder jacket having a folding flap disposed thereon, which cooperates with a arranged at the periphery of the transfer cylinder folding blade in such a way that the signatures are folded in the folding door by cooperation with the folding blade.

The term web strand in this context includes any type of web-shaped material, such as e.g. a paper web or a paper web strand. The term signature here refers to any portion of material that is separated from the web-like material, such as e.g. a sheet of paper.

Further features of the invention will become apparent from the dependent claims.

Fig. 1

eine schematische Seitenansicht einer ersten Ausführungsform eines erfindungsgemäßen Falzapparats mit variabler Abschnittslänge, der zur Herstellung von längeren Signaturen eingestellt ist;

Fig. 2

eine schematische Seitenansicht des Falzapparats mit variabler Abschnittslänge nach Fig. 1, der zur Herstellung von kürzeren Signaturen eingestellt ist;

Fig. 3

eine schematische Seitenansicht einer zweiten Ausführungsform eines erfindungsgemäßen Falzapparats mit variabler Abschnittslänge, der zur Herstellung von kürzeren Signaturen eingestellt ist;

Fig. 4

eine schematische Seitenansicht des Falzapparats mit variabler Abschnittslänge nach Fig. 3, der zur Herstellung von längeren Signaturen eingestellt ist;

Fig. 5

einen Querschnittsansicht des in Fig. 3 dargestellten Falzapparats mit variabler Abschnittslänge; und

Fig. 6

zeigt einen Querschnittsansicht des in Fig. 4 dargestellten Falzapparats mit variabler Abschnittslänge.

The construction and operation of the invention as well as its additional objects and advantages will be described below with reference to the drawings. In the drawings show:

Fig. 1

a schematic side view of a first embodiment of a variable section length folding apparatus according to the invention, which is set to produce longer signatures;

Fig. 2

a schematic side view of the variable-length folding apparatus of Figure 1, which is set to produce shorter signatures ..;

Fig. 3

a schematic side view of a second embodiment of a variable section length folding apparatus according to the invention, which is set to produce shorter signatures;

Fig. 4

a schematic side view of the folder with variable section length of Figure 3, which is set to produce longer signatures ..;

Fig. 5

a cross-sectional view of the variable section length folding apparatus shown in Figure 3; and

Fig. 6

shows a cross-sectional view of the variable section length folding apparatus shown in Fig. 4.

Fig. 1 shows a schematic side view of an embodiment of a folding machine with variable section length, comprising a knife cylinder 3, a transfer cylinder 4 and a jaw cylinder 5.

The knife cylinder 3 has cutting blades 13 to cut a web strand 1 into signatures of a desired length. The transfer cylinder 4 has cutting bars 11 which cooperate with the cutting blades 13 of the knife cylinder 3 for cutting the web strand 1. At the periphery of the transfer cylinder 4 grippers 7 are arranged to hold the signatures. The transfer cylinder 4 has adjustable diameter sections which are arranged on its periphery. Each adjustable diameter portion may adjust the size of a portion of the transfer cylinder 4. Thus, the effective diameters of the transfer cylinder 4 and the knife cylinder 3 are suitable for producing variable-length-length signatures. The adjustable diameter sections are designed as adjustable rollers 9. As the arrows in the adjustable rollers 9 show, each adjustable roller 9 can be adjusted by means of adjusting means 15, e.g. a winch, such as an eccentric winch or a linear winch, or be moved by any other suitable adjustment device. Fig. 1 shows how the size of the adjustable parts of the transfer cylinder can be adjusted by the adjustable rollers 9 are retracted or extended, so in which the adjustable rollers 9 are moved to the central axis 12 of the transfer cylinder 4 and away from her to reduce or enlarge the adjustable sections of the transfer cylinder 4.

The transfer cylinder 4 is provided along its periphery with folding blades 6 and a jaw cylinder 5 is provided along its periphery with jaws 8. The Folding blade 6 on the transfer cylinder 4 cooperate with the jaws 8 on the jaw cylinder 5 by folding the signature into the jaws 8.

A dancer roller 2 is located in a region in which the web strand 1 enters the section of the device in which the signatures are cut. The dancer roller 2 equals differences in the length of the web strand, such as e.g. Differences caused by the setting of the effective diameter of the transfer cylinder 4 from.

FIG. 2 is a schematic side view of the variable section length folder of FIG. 1 set to produce a shorter signature. FIG. The adjustable rollers 9 are retracted, i. moved in the direction of the central axis 12 of the transfer cylinder 4 in order to reduce the effective diameter of some sections of the transfer cylinder 4 and thus to reduce the signature length. The dotted lines represent the positions of the adjustable rollers 9 for the production of longer signatures.

Fig. 2 shows an example of the dimensions of the transfer cylinder 4. The diameter of the transfer cylinder 4 is e.g. 1000 mm and the diameter of the adjustable rollers is 101.764 mm. If the adjustable roller 9 is set to intersect shorter signatures, the length of a connecting line between a cutting bar 11 and a folding blade 6 may be e.g. 318,797 mm. In this case, the connecting line between the cutting bar and the folding blade is substantially rectilinear. If the adjustable roller 9 is adjusted so that the device cuts longer signatures, the length of the connecting line between a cutting bar 11 and a folding blade 6 is e.g. 334,855 mm. The total length of 334,855 mm is the sum of the three lengths 155.285 mm, 34.192 mm and 145.378 mm. The difference in length of the connecting line between the folding blade 6 and the cutting strip 11 is thus 16,058 mm.

The operation of the variable section length folding apparatus will be explained with reference to Figs. The web strand 1 is passed around the dancer roller 2 and then enters the Section of the knife cylinder 3 and the transfer cylinder 4, in which the signatures are cut. The dancer roller 2 allows for differences in the track length, which are compensated by the transfer cylinder 4. The differences are caused by the adjustable roller 9 on the transfer cylinder 4, when it is adjusted to longer sections. The knife cylinder 3 and the transfer cylinder 4 rotate in the opposite direction, so that the cutting blade 13 of the knife cylinder meet during the rotation of the cylinder on the cutting bars of the transfer cylinder 4. The web strand 1 is held by means of a gripper 7 on the transfer cylinder 4. While the transfer cylinder 4 rotates counterclockwise, the web strand is guided along the periphery of the transfer cylinder 4. The adjustable roller 9 is mounted so that the effective diameter of the transfer cylinder 4 in the area between the folding blade 6 and the cutting bar 11 or the gripper 7 corresponds to the desired signature length. The grippers or puncture needles 7 on the transfer cylinder 4 give the signature stop. The transfer cylinder 4 then rotates to transport the signature into the jaw cylinder 5 and the folding blade 6 folds the signature into the jaw 8. The difference in signature length results from the length of the connecting line between the gripper 7 and the associated folding blade 6. The dimensions which have been described with reference to FIG. 2 show by way of example a possible difference in the signature length or the book length which can be adjusted in this way.

Fig. 3 shows a schematic side view of a second embodiment of a folding machine with variable section length for the production of longer signatures. The corresponding elements of the various embodiments are each denoted by identical reference numerals. Fig. 3 shows a knife cylinder 3, which can be moved to the transfer cylinder 4 to or from the transfer cylinder 4 away. The transfer cylinder or folding blade 4 is equipped along its periphery with cutting strips 11 and grippers 7. The grippers 7 are arranged on the gripper shafts 14. The grippers 7 and the cutting bars 11 can be moved together toward or away from the central axis 12 of the transfer cylinder 4 to adjust the effective diameter of a portion of the transfer cylinder 4. Fig. 3 shows the Position of the cutting bar 11 and the gripper 7 in a retracted position for the production of shorter signatures. The knife cylinder 3 is moved toward the transfer cylinder 4, so that the cutting blades 13 of the knife cylinder 3 contact the cutting bars 11 during the cutting operation. If a longer signature is desired, the cutting bars 11 are moved outwards together with the grippers 7 away from the center axis 12 of the transfer cylinder 4, so that the effective diameter of sections of the transfer cylinder 4 is increased. Fig. 4 shows the extended position of the grippers or puncturing needles 7 and the cutting bars 11 for producing longer signatures. The knife cylinder 3 is moved away from the transfer cylinder 4 in order to cooperate with the cutting strips 11.

Fig. 5 shows a cross-sectional view of the variable section length folder of Fig. 3. Fig. 5 shows the cutter bars 11 and grippers 7 in a retracted position to produce shorter signatures. The cutting bars 11 and the grippers 7 have been moved in the direction of the central axis 12 of the transfer cylinder. The knife cylinder 3 has been moved toward the transfer cylinder 4 so that the cutting blades 13 of the knife cylinder 3 contact the cutting bars 11 during the cutting operation. Fig. 5 shows the dimensions of the transfer cylinder 4. The diameter of the transfer cylinder 4 is e.g. 1000 mm. The length of the web strand 1 from the cutting bar 11 to the next folding blade 6 is e.g. 299.47 mm. This is the sum of the straight connecting line whose length is e.g. 258.11 mm, and the curved connecting line whose length is e.g. 41.36 mm, as shown in FIG. 5.

Fig. 6 is a cross-sectional view of the variable section length folder of Fig. 4. The cutter bars 11 and grippers 7 are in an extended position for producing longer signatures. The knife cylinder 3 has been moved away from the transfer cylinder 4, so that the cutting blades 13 of the knife cylinder 3 touch the cutting bars 11 during the cutting process. The diameter of the transfer cylinder 4 is for example 1000 mm. The length of the web strand 1 from the cutting bar 11 to the next folding blade 6 is 310.02 mm. this is the Sum of the straight connecting line whose length is 283.19 mm, and the curved connecting line whose length is 26.83 mm, as shown in FIG.

List of reference numbers

1

web strand

2

dancer roll

3

diameter cylinder

4

Transfer cylinder or folding cylinder

5

jaw cylinder

6

folding blade

7

Gripper or needle

8th

flap

9

adjustable roller

11

cutting bar

12

central axis

13

cutting blade

14

gripper shaft

15

winch

Claims (9)

1. Cutting device with variable cut-off length with a cutting cylinder (3) and a transfer cylinder (4), which interacts with the cutting cylinder (3) for cutting signatures of a desired length and has a centre axis (12) and a periphery, wherein arranged on the periphery of the transfer cylinder (4) is an adjustable diameter section, which is connected to the transfer cylinder (4) and is movable towards the cylinder centre axis (12) and away from the cylinder centre axis (12) in order to adjust the desired signature length,
   characterised in that the adjustable diameter section comprises an adjustable roller (9) and is configured as such a roller, which is movable towards the cylinder centre axis (12) and away from the cylinder centre axis (12).
2. Device according to Claim 1, characterised in that adjusting elements (15) acting on the adjustable diameter section are provided, by means of which the adjustable diameter section is movable towards the centre axis (12) of the transfer cylinder (4) and away from this.
3. Device according to one of the preceding claims, characterised in that this contains signature holding elements (7) as well as a folding blade (6), which are respectively connected to the transfer cylinder (4) and are arranged in the region of the periphery of the cylinder at a fixedly predetermined distance from the central rotational axis of the cylinder, wherein the adjustable diameter section is arranged between the signature holding elements (7) and the folding blade (6).
4. Device according to Claim 3, characterised in that this comprises a cutting blade (13) fastened to the cutting cylinder (3) as well as a cutting strip (11) arranged in the region of the periphery of the transfer cylinder (4), which interacts with the cutting blade (13) during a rotation of the cutting cylinder (3) and the transfer cylinder (4).
5. Device according to Claim 1, characterised in that the transfer cylinder (4) rotates at a substantially constant angular velocity.
6. Device according to one of Claims 1 or 2, characterised in that the adjustable diameter section comprises signature holding elements (7) as well as a cutting strip (11), and that the signature holding elements (7) as well as the cutting strip (11) are movable towards the centre axis (12) of the transfer cylinder (4) to change the signature length.
7. Device according to one of Claims 3 to 6, characterised in that the signature holding elements (7) are formed by grippers.
8. Device according to one of Claims 3 to 6, characterised in that the signature holding elements (7) are formed by needles.
9. Folding machine in a rotary press for generating signatures with variable cut-off length, characterised in that the folding machine includes a cutting device according to one of Claims 1 to 8.

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