EP1634831B1 - Web spreading method and web spreading device - Google Patents

Abstract

The web stretching method entails feeding a first (Br) and a second (Bl) web strand next to one another and offset parallel to one another by a defined spread dimension. At least one of two deflection devices (5,6) is adjustable from a first position into a second new position in which the first web strand covers a different travel distance than in the first position but maintains its direction of feed so that the spread dimension is adjusted but the wrap angle of the second web strand is not altered through the adjustment of the deflection device. An independent claim is included for a web stretching device by which the aforesaid method is put into practice.

Description

The invention relates to a method and apparatus for spreading a web in a web processing machine. The web-processing machine may in particular be a printing press, for example an offset printing press. Preferred examples are web-fed rotary printing presses, such as those used in commercial printing or more preferably in the printing of large newspaper editions.

The DE 100 23 169 Al describes a Bahnspreizvorrichtung with two arrow-shaped turning bars, which are arranged in the web conveying direction behind a longitudinal cutting means behind the other and are mounted relative to each other pivotable in a machine frame. Two web strands of a longitudinally cut web are conveyed side by side through the web spreading device and thereby loop one after the other half of the arrow-shaped turning bars, so that the web strands are offset in parallel and have between them a Spreizmaß when they run off the web spreading device. By pivoting only one or both arrow-shaped turning bars relative to each other, the lengths of the web strands between the arrow-shaped turning bars and the wrap angle with which the web strands wrap around the arrow-shaped turning bars, thereby changing the Spreizmaß. However, go with the adjustment of Spreizmaßes web tension changes.

Another web spreading device, which is considered to be the closest prior art, will be EP 1 386 869 A2 disclosed.

It is an object of the invention to reduce in the adjustment of Spreizmaßes between parallel side by side conveyed in a spreader web strands web tension fluctuations, preferably to avoid.

In a web spreading method, as the invention relates, a first web strand and a second web strand are conveyed side by side in a web-processing machine and displaced parallel to one another by an expansion dimension. The Spreizmaß is the measured between the facing edges of the web strands clear distance after the parallel offset. In order to obtain the spread dimension, both web strands can be to themselves and relative to each other or it can be offset in parallel only one of the web strands to itself and relative to the other. The first web strand wraps successively around a first deflection device, which forms a first deflection axis for the first web strand, and downstream, a next, second deflection device, which forms a second deflection axis for the first web strand, each with a wrap angle, preferably each with the same wrap angle. The deflection devices are arranged, namely each obliquely to the conveying direction of the incoming first web strand, that the first web strand running from the second deflection device is offset parallel to the first web strand running onto the first deflection device. In order to adjust the spread dimension, at least one of the deflection devices is moved from a first position to another, second position, in which the first web strand travels a different path length between the first deflection device and the second deflection device than in the first position.

According to the invention, the second position of the displaced deflection device is selected such that the conveying direction which the first web strand has between the deflection devices is not changed by the adjustment. This means that the wrap angle is not changed, at least not by the adjustment of the at least one of the deflection devices. The first web strand therefore runs after the adjustment of the Spreizmaßes of the same angular position on the outer circumference of the first deflection and at the same angle on the outer circumference of the second deflection on as before the adjustment. Since web tension changes by the spreading depend primarily on changes in the wrap angle, web tension changes are avoided by the spreading method according to the invention. Particularly preferred are an inlet guide device upstream of the first deflection device and one of the second deflection device downstream following Outlet guide arranged so that the conditions in the emergence of the first web strand on the first deflection and the expiration of the second deflection by the adjustment does not change, so that the wrap is not changed not only by the adjustment itself, but absolutely the same remains.

The invention relates not only to a web spreading method, but also to a web spreading device by means of which web strands conveyed side by side in a processing machine can be displaced parallel to one another in order to set the spread dimension. The invention relates not only to the built-in web-processing machine, but also for the first intended Bahnspreizvorrichtung. The web spreading device comprises a frame, the first deflection device and the second deflection device. As already explained, the deflecting devices are formed and arranged such that the first web strand is offset in parallel by looping around the deflecting devices and thus the spreading dimension is set entirely or in part. At least one of the deflecting devices, preferably the second deflecting device, is adjustably mounted in the frame along a displacement path in order to be able to set the spreading dimension.

The device according to the invention is characterized in that the adjustment path is straight and extends in the conveying direction, which has the first web strand between the first and the second deflection device. As pointing in the direction of conveyance is also understood a distance from the first web strand parallel to the web plane formed by the first web strand between the deflecting. Such a choice of the adjustment ensures that the first web strand between the deflecting maintains its conveying direction during the entire adjustment of the deflection. The adjustment movement as such, which executes the at least one adjustable deflecting device from the first to the second position, thus does not change the wrap angle with which the first web strand wraps around the first deflecting device and the second deflecting device. The respective wrap angle can be changed at most by the adjustment of an upstream inlet guide or a downstream outlet guide.

Preferably, however, the wrap angle is always the same in the first and second positions of the at least one adjustable deflection device, and more preferably also in other positions which the deflection devices for the first web strand can advantageously occupy relative to one another. Due to the straightness of the displacement, the wrap angle is invariant to any adjustment movement made along the displacement path between the first position and the second position.

If the at least one adjustable deflection device can be adjusted to a position in which it does not effect an offset of the first web strand and is preferably not in contact with the first web strand, the adjustment path preferably extends straight into this position, which is not unavoidable must be the case. An adjustability up to a position of the at least one deflecting device in which the web does not wrap around this deflecting device and preferably also the other of the deflecting devices and even more preferably has no contact with the deflecting devices at all, is advantageous for drawing in a new web. If the at least one adjustable deflection device can assume such a position, this position in the sense of the invention is of course neither the "first position" nor the "second position".

In preferred embodiments, the at least one of the deflection devices, which is adjusted for the adjustment or adjustment of Spreizmaßes, adjustable not only in a first and a second position, but in more than two different positions in which the first web of strand between the deflection another Path length than travels in the first position, but retains its conveying direction and even more preferably the wrap angle.

In preferred embodiments, as for the first web strand, deflection devices are also provided for the second web strand, of which at least one is adjustable. By means of the deflecting devices provided for the second web strand, namely a further first deflecting device and a further second deflecting device, the second web strand can be offset in parallel. In terms of the others Deflection devices preferably applies with respect to the deflecting means for the first web strand.

Not indispensable in each, but in one or more of the productions that can be carried out by means of the web-processing machine, preferably printed productions, the deflecting devices for the web strands each assume such positions that both the first web strand and the second web strand are offset in parallel so as to pass through the parallel offset of both web strands to get the Spreizmaß. It is advantageous if the wrap angle with which the first web strand wraps around its associated deflection devices for a parallel offset and the wrap angle with which the second web strand wraps around its associated further deflection devices for a parallel offset are advantageous. This preferably applies to each of the positions which the at least one adjustable deflection device for the first web strand and the at least one further adjustable deflection device for the second web strand can occupy between the respective first and second position.

It is particularly preferred if each of the web strands is offset in parallel in each production. In order to be able to convey at least one of the web strands nevertheless with as little parallel offset as possible, the deflecting means for this at least one of the web strands to the conveying direction of the respective web strand obliquely at an angle greater than 85 ° and less than 90 °, preferably at least 87 ° and at most 89 °, should be. The deflection devices which are assigned to the other of the web strands have advantageously at a smaller angle of attack obliquely to the conveying direction of the other web strand, preferably with an angle of attack which is at least 45 ° and at most 85 °, ie an angle of attack from the angle range usual for spreading devices. The feature of the different angles of employment as such, ie without the adjustment paths designed according to the invention, is already advantageous for the reduction of web tension fluctuations, but in turn can advantageously be further developed by such a configuration of the adjustment paths.

The web strands may leak after spreading in different directions from the web spreading device. However, they are in the view perpendicular to the strand level of one of the web strands parallel. Preferably, however, they form staggered but parallel planes or a single, common plane when leaving the web spreader.

The web strands which are spread apart from one another by means of the web spreading device are conveyed to a processing plant of the processing machine, for example a printing unit of a printing press, during production and are processed there in accordance with the purpose of the processing machine. In the case of a printing press, they are printed on one or both sides one or more colors and then further processed to the finished printed product.

Preferred embodiments of the invention are also described in the subclaims and by the combinations of the claims.

Figur 1

eine Bahnspreizvorrichtung eines ersten Ausführungsbeispiels in einer Rollenrotationsdruckmaschine,

Figur 2

die Bahnspreizvorrichtung in einem Zustand, in dem zwei Stränge einer Bahn symmetrisch voneinander abgespreizt und mittig auf je einen Falztrichter geführt werden,

Figur 3

die Bahnspreizvorrichtung in einem Zustand, in dem die Stränge einer Bahn asymmetrisch voneinander abgespreizt und mittig auf je einen Falztrichter geführt werden,

Figur 4

die Spreizvorrichtung in einem Zustand, in dem die Stränge einer Bahn asymmetrisch voneinander abgespreizt und einer der Bahnstränge mittig und der andere der Bahnstränge außermittig auf je einen Falztrichter geführt werden,

Figur 5

eine Bahnspreizvorrichtung eines zweiten Ausführungsbeispiels in der gleichen Rollenrotationsdruckmaschine und

Figur 6

die Bahnspreizvorrichtung des zweiten Auführungsbeispiels in einem Zustand, in dem die Stränge einer Bahn asymmetrisch voneinander abgespreizt und mittig auf je einen Falztrichter geführt werden.

The invention will be explained below with reference to exemplary embodiments. The features disclosed in the exemplary embodiments each form, individually and in each feature combination, the subjects of the claims and the embodiments described above. Show it:

FIG. 1

a web spreading device of a first embodiment in a web-fed rotary printing press,

FIG. 2

the web spreading device in a state in which two strands of a web are spread apart symmetrically from each other and guided centrally on a respective former,

FIG. 3

the web spreading device in a state in which the strands of a web are asymmetrically spread apart from each other and guided centrally on a respective former,

FIG. 4

the spreading device in a state in which the strands of a web asymmetrically spread apart and one of the web strands centered and the other of the web cords are guided eccentrically on a respective former,

FIG. 5

a web spreading device of a second embodiment in the same web-fed rotary printing press and

FIG. 6

the web spreading device of the second Auführungsbeispiels in a state in which the strands of a web are asymmetrically spread apart from each other and centered on a respective former.

FIG. 1 shows components of a web-fed rotary printing press comprising a web spreading device according to the invention. Shown is the path of a web to be printed B of a reel changer 1 via a web spreading device to a printing unit 9, which is formed as a printing tower. The spreading device includes a longitudinal cutting device 4, which serves to cut the web B longitudinally into two web strands, namely a first web strand Br and a second web strand Bl, and deflection devices 5 and 6, which serve to form the formed web strands Bl and Br parallel to one another. The splayed web strands Bl and Br are conveyed in the web conveying direction F to a Drucktunn 9 and there printed on both sides multi-colored. From the printing tower 9, two cylinder bridges, each formed from two printing on the web strands Bl and Br blanket cylinders and each associated with a plate cylinder, are shown. Of course, the printing tower 9 can also comprise further such cylinder bridges in order to print the web strands Bl and Br four-color on both sides, for example. Behind the printing tower 9, the web strands Bl and Br are either separately or each with at least one further web strand on former, of which a former 20 is shown, or together on a common former 20 and separated in the formers or together in the former longitudinally folded. Behind the former 20 or the plurality of formers in the web conveying direction F, a folder or more folders can be arranged for cross cutting and Querfalzen.

The uncut web B entering the spreading device from the roll changer 1 is conveyed via an inlet guide 3 to the longitudinal cutting device 4. The longitudinal cutting device 4 is essentially made up of two successive and Absetzbaren cutting rollers formed, between which the web B is conveyed through. As a result of the longitudinal section, the first web strand Br is formed as the right and the second web strand B1 as the left web strand. The web strands B1 and Br running parallel to each other are guided via a first deflection device 5, an immediately following second deflection device 6 and an outlet guide device 7. Subsequently, they are conveyed to the printing tower 9 via further guide devices, of which one next to the outlet guide 7 next adjacent guide 8 is shown. The inlet guide device 3, the longitudinal cutting device 4 and the first deflection device 5 are mounted in a fixed position relative to each other in a frame 2. The inlet guide 3 is a guide roller which is rotatably mounted in the frame 2. The first deflection device 5 is not rotatable.

The second deflection device 6 is movably supported linearly guided together with the outlet guide 7 in the frame 2. A linear guide track 11 of the bearing is fixedly connected to the frame 2. The second deflection device 6 and the outlet guide device 7 are continuously movable back and forth along the linear guide 11 between two end positions. One of the two end positions is in FIG. 1 in solid line and the other shown in dashed line. A control device 15 controls a drive device 12 based on instructions that can be input to the control device 15 or to a higher-level machine control such that the second deflection device 6 and the outlet guide device 7 assume the desired adjustment position on the adjustment path.

FIG. 2 shows the web spreading device in a first state in a plan view of the web plane. The second deflector 6 and the outlet guide 7 are divided in the middle of each in two symmetrical halves. The two halves are independently linearly guided on a frame-fixed linear guide 11 (FIG. FIG. 1 ) movably mounted. The adjustment paths and also the end positions of the two halves are the same. The movements of the two halves are controlled by the control device 15 via the drive device 12 and optionally also regulated. Thus, the two halves can in particular be moved together or individually or else in opposite directions along their adjustment paths and fixed in any position between the end positions.

By the central division, a second left diverter 6l and a second right diverter 6r and a left exit guide 7l and a right exit guide 7r are formed. The second left diverter 6l and the left exit diverter 7l are associated with the left web strand Bl, i. they only come in contact with the left-hand track Bl. The second right hand deflector 6r and right hand runner 7r are associated with the right hand web strand Br, i. they only come in contact with the right-hand track Br. Accordingly, there is also an assignment in the first deflection device 5. The first deflection device 5 is, however, fixed in the frame at the two opposite frame sides 2l and 2r. The first deflection device 5 functionally breaks down into a first left-hand deflection device 5l and a first right-hand deflection device 5r. The deflection devices 5l, 5r, 6l and 6r each have the same cross section. In the exemplary embodiment, they are each formed as circular rods.

The first deflection devices 5l and 5r and in particular the deflection axes formed by them form in the plan view of the plane of the incoming web B an arrow shape, the tip of which faces the web conveying direction F. The first deflection devices 5l and 5r are firmly connected to one another in the middle in the area of the "arrowhead". The tip itself is worked around to avoid the risk of scoring the web B. The longitudinal cutting device 4 and the tip formed by the first deflecting means 5l and 5r lie exactly on the machine axis S. The arrangement of the parts of the spreading device associated with the left web strand Bl is symmetrical with the arrangement of the parts associated with the right web strand Br are. In that regard, the machine axis S also simultaneously forms an axis of symmetry of the spreading device.

The right-hand deflection devices 5r and 6r form mutually parallel deflection axes for the right-hand web strand Br. The adjustment paths of the second deflection devices 6l and 6r run in such a way that the parallelism of the deflection axes in each Adjustment of the second deflection 6l and 6r is maintained.

The outlet guide means 7l and 7r are arranged relative to the second deflecting means 6l and 6r so that the web path level defined by the second left deflecting device 61 and the left outlet guide 71 in the case of wrapping and that of the second right deflecting device 6r and the Right outlet guide 7r in the case of wrapping defined Bahnstrangebene is parallel to the orbital plane, which is predetermined by the inlet guide 3 and the two first deflection 5 and 5r in the case of their wrap. The outlet guide devices 7l and 7r form deflection axes pointing perpendicular to the web conveying direction F. The second left-hand deflecting device 61 and the left-hand outlet guide 71 are mounted together on a left-hand carriage 101. The bearing on the carriage 101 is such that the deflection axes of the second left deflection 61 and the left outlet guide 71 relative to the carriage 101 are adjustable at most in the context of tolerance-compensating adjustments. The same applies mutatis mutandis to the storage of the second right deflection 6r and the right outlet guide 7r on the right slide 10r. The two carriages 101 and 10r are movable on their respective frame side 2l and 2r each along a separate linear guide 11, wherein the left linear guide 11 is parallel to the right linear guide 11 and is arranged with respect to the web conveying direction F at the same height. The two outlet guide means 7l and 7r may be rotatably mounted on the respective carriage 101 and 10r. Basically, the same applies to the second deflection 61 and 6r, but for the deflection means 6l and 6r of the simpler construction because of the formation is preferred in each case as a non-rotatable rod.

In the in FIG. 2 shown first state of the spreading take the second left deflecting 61 and the second right deflector 6r each an adjustment position in which they define together with the outlet guide 7r and 7l a single plane to the incoming web B plane parallel to the web strands Bl and Br , In such positions, the second deflecting means 6l and 6r also form an arrow shape with each other, but with a narrow gap between their free ends, which exactly overlap one another in these positions. The deflection axes formed by the second deflection devices 6l and 6r intersect accordingly.

The deflection axes formed by the outlet guide devices 7l and 7r are aligned in these adjustment positions.

The web B enters symmetrically to the machine axis S in the spreading device. Because of this track symmetry and the positioning of the second deflection devices 6l and 6r in a common plane, the two web strands Bl and Br are each spread apart to one side away from the machine axis S by the same offset parallel to each other. This results in the Spreizmaß X, which designates the transversely to the web conveying direction F measured clear distance between the web strands Bl and Br. "M" is the distance measured in the web plane between a left boundary line and a right boundary line, up to which the web strands Bl and Br can be displaced parallel to the left outside or right outside with sufficient web width by means of the spreading device. In the illustrated state of the spreading device with symmetrical inlet of the web B remains between the left outer edge of the left web strand Bl and the left boundary line a distance X / 2. A similar distance remains between the right boundary line and the right web edge of the right web strand Br. Due to the web width Z, the symmetrical inlet, the symmetrical section and the symmetrical spread to the Spreizmaß X, the left web strand Bl centered in its associated Längsfalztrichter 20th , and the right web strand Br also runs centrally into its associated longitudinal folding hopper 21. The web strands Bl and Br are also printed symmetrically to their longitudinal fold Ll and Lr. The widths of the web strands Bl and Br are indicated by A, and the widths on both sides of the longitudinal folds Ll and Lr are indicated by A '. The following applies: Z = 2A = 4A '. It should be noted that the former 20 and the former 21 can be formed by a single former.

In the in the FIG. 3 illustrated second state of the spreading device, the web B runs asymmetrically to the machine axis S in the spreading device. The symmetry longitudinal axis of the web B is denoted by S _B. It is laterally offset to the machine axis S. The web B is cut asymmetrically into a left web strand Bl and a right web strand Br by means of the cutting device 4 in accordance with the offset of the axes S and S _B.

In the second state, the right-hand carriage 10r with the second right-hand deflecting device 6r and the right-hand outlet guide 7r does not protrude into the path of the right-hand web strand Br and, accordingly, does not have an encircling contact with the right-hand web strand Br. The right-hand web strand Br also does not wrap around the web first right deflection 5r. The right web strand Br is therefore conveyed through without lateral displacement by the spreading device. The adjustment position of the second right deflection 6r and the right outlet guide 7r corresponds to the in FIG. 1 dashed line position shown. However, the second left-hand deflecting device 61 and the left-hand outlet guide 71 are moved into the path of the left-hand web track Bl, for example, into the in FIG. 1 shown in a solid line other end position. The reel changer 1 is in the embodiment of FIG. 3 adjusted so that the right track strand Br is promoted as far as possible right outside. The right outer edge of the web track Br coincides with the right boundary line of the web spreading device. The arrangement of the spreading relative to the formers 20 and 21 is such that the web strands of a web B of maximum width Z = M run without parallel offset, each centered on the former 20 and 21. In the web example of the FIG. 3 the right-hand web strand Br is conveyed with its outer edge at its outermost right-hand edge along the center of the associated longitudinal rebate hopper 21. The narrower to the double offset of the axes S and S _B left web strand Bl would be eccentrically promoted to its associated Längsfalztrichter 20, although he would pass the web spreading uninfluenced. However, the second left-hand deflecting device 61 has been moved together with the left-hand outlet guide 71 relative to the first left-hand deflecting device 51 into such an adjustment position that it experiences a parallel displacement corresponding to the spreading dimension X, which is so great that the left-hand web strand Bl is centered is conveyed to the associated Längsfalztrichter 20.

For the web guiding example of FIG. 3 it is assumed that the web B has a different width Z than the web B of the in FIG. 2 has shown first example. The distance X of the outer edge of the left web strand Bl from the left boundary line corresponds to the spread dimension X. The widths of the web strands Bl and Br are indicated by B and C.

On both sides of the fold lines Ll and Lr, the web strands B1 and Br have the same widths for the center conveyance on the longitudinal fold hoppers 20 and 21, which are indicated for the left web strand Bl with B 'and for the right web strand Br with C'.

In the in FIG. 4 the third track example shown, the web B is supported by the paster 1 symmetrical to the machine axis S, ie, the machine axis S coincides with the central longitudinal axis S _{B of} the web B. Since the longitudinal section is performed on the machine axis S, the two resulting web strands Bl and Br each have the same width A, wherein it is assumed that the width Z of the web is the same as in the web guiding example of FIG. 2 is. In the web guide example of FIG. 4 the web spreading device is in the second state. The right-hand web strand Br passes the web spreading device accordingly unaffected. Unlike in the track example of the FIG. 3 However, the right web strand Br to the rightmost edge has a distance Y, so that the right web strand Br as in the first web guiding example of FIG. 2 shown only longitudinally would be folded along, if it would spread the web spreading device to the parallel offset Y / 2 with respect to the machine axis S to the right outside parallel. In the web strand guide of the third web guiding example, the right web strand Br is consequently conveyed eccentrically onto the longitudinal folding hopper 21 and, accordingly, folded longitudinally off-center. The printed image printed on it is correspondingly asymmetrical. The partial width of the right web strand Br to the one side of the longitudinal fold line Lr is denoted by A "and the width differing therefrom to the other side of the longitudinal fold line Lr is denoted by A '". The second left-hand deflection device 61 assumes such an adjustment position relative to the first left-hand deflection device 51 that the left-hand web strand Bl is conveyed centrally onto the longitudinal-folding hopper 20. The parallel offset X of the left web strand Bl corresponds to the Spreizmaß. The partial widths on both sides of the longitudinal fold line L1 are the same in the left-hand web strand B1 and accordingly each denoted by A '.

Upon entry of a free web start of a new web, the new web is passed from the reel changer 1 via the inlet guide 3 and between the cut-off cutting rollers of the cutter 4. Subsequently, the web start is straight, ie without wrapping the deflectors 51 to 6r and Outlet guide devices 71 and 7r led to the other outlet guide 8 and fed by looping the Auslaut guide 8 and optionally on even more guide devices through the pressure nip or the plurality of pressure column of the printing tower 9 to the formers 20 and 21. The former 20 and 21 may, as already mentioned, be a single former, to which both web strands Bl and Br are brought together. The second baffles 6l and 6r and the outlet baffles 7l and 7r take their in FIG. 1 Dashed end position shown, which can also be referred to as retraction position. The still uncut web at the feeder is also shown in dashed lines and designated B '. After the web B 'has reached the or the former, it is cut longitudinally with the cutter 4 in the web strands Bl and Br. Only when the web strands Bl and Br have passed the outflow guide devices 7l and 7r downstream downstream outlet guide device 8, or will only one of the second deflection 6l and 6r and thus together with the associated outlet control devices 7l and 7r in their Adjustment (s) moves and thereby set the desired Spreizmaß X. As a result of the continuous travel movement of the second deflection device (s) 61 and / or 6r and outlet guide device (s) 71 and / or 7r, the web strands Bl and Br are continuously spread apart in parallel until the spread dimension X is set.

In order to reduce the friction, the deflecting devices 51 to 6r have blowing air holes on their mantle surfaces, through which the entangling web strands Bl and Br can be exposed to blowing air, as known from turning bars. As soon as one of the deflection devices 51 to 6r is moved against the relevant web strand Bl or Br, the blowing air is switched on. The switching on of the blowing air is of course automated, for example as a function of the adjustment position of the second deflection devices 6l and 6r and preferably under the control of the control device 15.

As already mentioned, the web level defined by the second deflection devices 6l and 6r and the outlet guide devices 7l and 7r is the web plane defined by the inlet guide device 3 and the first deflection devices 5l and 5r parallel. The web plane between the inlet guide 3 and the first deflection 5l and 5r on the one hand and the Bahnstrangebenen between the second deflection 6l and 6r and the outlet guide means 7l and 7r on the other hand are parallel in all adjustment positions.

The predetermined by the two linear guides 11 adjustment of the second deflection 6l and 6r and outlet guide 7l and 7r are perpendicular to the plane defined by the inlet guide 3 and the first deflection 5l and 5r web plane. The adjustment paths each have a part of their linear length in the conveying direction F, which have the web strands Bl and Br between the deflecting devices 5 and 6 in the case of their wrap. The pointing in the conveying direction F partial lengths extend from the respective position for maximum spread to a position in front of the FIG. 1 dashed line position for zero spread. It follows that the second deflection devices 6l and 6r first dive out of the end position of the zero spread with an adjustment in the direction of the end position of the maximum spread in the respective web strand Bl and Br. During a first phase of the web contact of the second deflection devices 6l and 6r, the wrap angle at which the web strands Bl and Br take the deflection devices 5 and 6 from the adjustment position of the respective first web contact changes continuously up to a further adjustment position. From the further adjustment position, which is referred to below as the first position, up to the position of the maximum spread, the wrap angle of the respective web strand Bl and Br remains unchanged. In preferably identical diameters of the deflection devices 5 and 6, the first position, from which the wrap angle no longer change in the course of the further movement in the direction of the position of the maximum spread, is achieved when, with respect to the left web strand Bl, the left Deflection devices 51 and 61 and with respect to the right web strand Br right deflection 5r and 6r are at the same height. The wrap angles are thus not changed in an adjustment of one of the second deflection 6r and 6l from the first position to every other position, which is located between the first position and the position for maximum spread and are in this sense It is also advantageous that the wrap angles are not only invariant per web strand Bl or Br against the possible adjustments of the respectively associated second deflection 61 or 6r, but that the wrap angle at which the left web strand Bl its wraps around both deflection devices 51 and 61, and the wrap angle with which the right-hand web strand Br wraps around its two deflection devices 5r and 6r are the same. The invariance of the wrap angle is already alone per Banhstrang Br and / or Bl advantageous for a web tension control. The equality of the wrap angles of both web strands Bl and Br further simplifies the web tension control.

In the first exemplary embodiment, all deflecting devices 51 to 6r have an angle of incidence of 75 ° obliquely to the conveying direction F of the first deflecting device 5, i. In the case of the invariance of the wrap angle of the adjusting movements of the second deflection 6l and 6r, this also already in the respective first position a large parallel offset of the two web strands Bl and Br result.

The Figures 5 and 6 show a Bahnspreizvorrichtung according to a second embodiment. The web spreading device of the second embodiment differs from that of the first only with respect to the employment of the right deflection to the conveying direction F of the incoming web strands Br and Bl and an offset of the longitudinal cutter 4. The adjustment paths are also straight over their entire length and each extend over a longitudinal section in the conveying direction F, which have the web strands Bl and Br between the deflecting devices 5 and 6, when the second deflecting devices 6 each assume a position on the adjustment path section extending from the respective first position to the respective position for maximum spreading. As in the first embodiment, the adjustment paths each extend only in the section between these two positions in this conveying direction F.

While the web spreading device of the first embodiment in some productions, as exemplified by the Figures 3 and 4 have been described, is configured so that one of the webs Br and Bl is conveyed by the spreader without wrapping its associated deflection devices 5 and 6, the spreader of the second embodiment is modified from that of the first embodiment so that the web strands conveyed therethrough Br and Bl are always offset in parallel preferably in each production and their respective associated deflection devices 5 and 6 always wrap around the same wrap angle. The second deflecting devices 5 and 6 are adjusted only for the purpose of pulling in a new track each in the dashed drawn retraction position in which the web start without wrapping the first and second deflecting 5 and 6 can be fed through the spreader through.

For the invariance of the wrap angle also for the productions of the Figures 3 and 4 To obtain the spreading device of the first embodiment can be modified so that one of the web strands Bl and Br, for example, the second, ie left web strand Bl, is offset in any of the adjustment positions of the second deflecting 61 parallel, but the spreading in each of the adjustment positions without Goes through offset. In this case, the first left diverter 51 and the second left diverter 61 would be exactly perpendicular to the direction of conveyance F of the incoming left train B1, and the second left diverter 61 would only receive equality of wrap angles with respect to the web plane of the incoming one Web strand Bl can be arranged above or below the web plane of the incoming web strand Bl.

FIG. 6 However, shows a contrast preferred modification of the spreading device of the first embodiment. The left-hand deflectors 51 and 61 correspond to the baffles 51 and 61 of the first embodiment. However, the right-hand deflectors are modified from the first embodiment and are therefore designated 5r 'and 6r'. The deflectors 5r 'and 6r' formed deflection axes are again parallel to each other, but with respect to the machine axis S asymmetric to the deflection axes of the left deflecting 51 and 61. The right deflection 5r 'and 6r' and thus the deflecting axes formed by each have an angle α at an angle to the conveying direction F. As the angle of attack α and angle β is understood in the web plane of the incoming web strand Br and Bl respectively the acute angle, the respective deflection axis with the conveying direction F of the incoming, ie on the respective first deflection 5r 'and 51 auflaufenden web strand Br and Bl, forms. The angle of attack α is greater than the angle of attack β, below which the left-hand deflecting device 51 and 61 and in particular their deflecting axes point obliquely to the conveying direction F of the incoming left-hand web strand B1. The angle of attack α should be greater than 85 ° and less than 90 ° and is 87 ° in the exemplary embodiment.

The adjustment path length of the second right-hand deflecting device 6r 'is selected such that in the end position for maximum spread the right-hand web strand Br is offset in parallel by the offset 2Y. The longitudinal cutting device 4 is offset by the dimension Y, ie by half the maximum offset, to the machine axis S. At the offset Y, the second right turn 6c takes its first position. The right web strand Br can be laterally corrected within the offset range from 0 to 2Y. In all productions, however, only the range between Y and 2Y is used to obtain the invariance of the wrap angle. The left web strand Bl is as in the web guiding examples of Figures 3 and 4 offset by the dimension X parallel to its inlet.

In the in FIG. 6 illustrated embodiment, the web B has the width Z. The web B is conveyed asymmetrically with respect to the machine axis S in the spreading device. Its right outer edge has the distance Y to the right boundary line. The right-hand deflection devices 5r 'and 6r' serve as web edge control in order to place the right-hand web strand Br with its right web edge on the right-hand boundary line. The right web track Br associated former 21 is in such a distance from the machine axis S arranged that the offset by the offset Y parallel right web strand Br is centered on the former 21. In the web guide example of FIG. 6 the two web strands Bl and Br are spread apart by the spreading dimension X + Y from each other.

In the two embodiments, as in the FIGS. 1 and 5 The adjustment paths of the second deflection devices 6l and 6r on the one hand and 61 and 6r 'on the other hand are perpendicular to the conveying direction F of the incoming web strands Bl and Br. In alternative embodiments, the displacement paths to the conveying direction F of the incoming web strands Bl and Br may also be oblique, ie under a respective inclination angle, in particular under each of the same angle of inclination, run. However, it also applies to obliquely extending displacement paths that such adjustment paths are straight and extend at least in one section into the conveying direction F, which have the web strands Bl and Br between the first deflection devices 5l and 5r and the second deflection devices 6l and 6r or 6r ' , Even with such obliquely to the incoming web strands Bl and Br facing adjustment paths, the web planes of the web strands Bl and Br remain between the deflecting devices 5 and 6 with adjustments between the first position and the position of the maximum spread.

Claims (23)

1. A web spreading method, in which:

   a) a first web strand (Br) and a second web strand (Bl) are conveyed next to each other in a web processing machine and are offset parallel to each other by a degree of spreading (X; X+Y);

   b) the first web strand (Br) loops around a first deflecting means (5r; 5r'), which forms a first deflecting axis, and around a second deflecting means (6r; 6r'), which is most immediately downstream on the web and forms a second deflecting axis, at a looping angle in each case and is thus offset in parallel,
   characterised in that

   c) at least one of the deflecting means (5r, 6r; 5r', 6r') is adjusted from a first position into a new, second position in which the first web strand (Br) travels a different path length between the deflecting means (5r, 6r; 5r', 6r') than in the first position but maintains its conveying direction (F), such that the degree of spreading (X; X+Y) is adjusted but the looping angle is not changed by adjusting the at least one of the deflecting means (5r, 6r; 5r', 6r').
2. The web spreading method according to the preceding claim, characterised in that the looping angle in the first position and in different new positions of the at least one of the deflecting means (5r, 6r; 5r', 6r') is the same in each case.
3. The web spreading method according to any one of the preceding claims, characterised in that the looping angle is the same in each position into which the at least one of the deflecting means (5r, 6r; 5r', 6r') is adjusted for or in a production.
4. The web spreading method according to any one of the preceding claims, characterised in that the second web strand (Bl) loops around an additional first deflecting means (5l), which forms a first deflecting axis for the second web strand (Bl), and around an additional second deflecting means (6l), which is most immediately downstream on the web and forms a second deflecting axis for the second web strand (Bl), at a looping angle in each case and is thus offset in parallel.
5. The web spreading method according to the preceding claim, characterised in that in order to adjust the degree of spreading (X; X+Y), at least one of the additional deflecting means (5l, 6l) is adjusted from a first position into a new, second position in which the second web strand (Bl) travels a different path length between the additional deflecting means (5l, 6l) than in the first position of the at least one of the additional deflecting means (5l, 6l) but maintains its conveying direction (F), such that the degree of spreading (X; X+Y) is adjusted but the looping angle of the second web strand (Bl) is not changed by adjusting the at least one of the additional deflecting means (5l, 6l).
6. The web spreading method according to any one of the preceding two claims, characterised in that the looping angle of the first web strand (Br) and the looping angle of the second web strand (Bl) are the same when the parallel offset of the web strands (Br, Bl) is different in size.
7. The web spreading method according to any one of the preceding three claims, characterised in that the looping angle of the second web strand (Bl) in the first position and in different new positions of the at least one of the additional deflecting means (5l, 6l) is the same in each case.
8. The web spreading method according to any one of the preceding four claims, characterised in that the looping angle of the second web strand (Bl) is the same in each position into which the at least one of the additional deflecting means (5l, 6l) is adjusted for or in a production.
9. A web spreading device, by means of which a conveyed first web strand (Br) and a second web strand (Bl) which is conveyed next to the first web strand (Br) in a web processing machine can be offset parallel to each other in order to set a degree of spreading (X; X+Y), said web spreading device comprising:

   a) a frame (2);

   b) a first deflecting means (5r; 5r') which forms a first deflecting axis for the first web strand (Br);

   c) and a second deflecting means (6r; 6r') which forms a second deflecting axis for the first web strand (Br) which is most immediate to the first deflecting axis in the conveying direction (F) of the first web strand (Br);

   d) wherein the first web strand (Br) is offset in parallel by looping around the deflecting means (5r, 6r; 5r', 6r') and the degree of spreading (X; X+Y) is thus completely or partially set;

   e) and wherein at least one of the deflecting means (5r, 6r; 5r', 6r') is mounted in the frame (2) such that it can be adjusted along an adjustment path in order to be able to set the degree of spreading (X; X+Y),
   characterised in that

   f) the adjustment path is linear in its entirety or at least in one section and extends in the conveying direction (F) which the first web strand (Br) exhibits between the deflecting means (5r, 6r; 5r', 6r').
10. The web spreading device according to the preceding claim, characterised in that the at least one adjustable deflecting means (6r; 6r') can be adjusted along the adjustment path in the conveying direction (F) from a first position into an end position, and the looping angle of the first web strand (Br) is the same in the first position and in the end position.
11. The web spreading device according to any one of the preceding claims, said web spreading device further comprising:

    an additional first deflecting means (5l) which forms a first deflecting axis for the second web strand (Bl);

    and an additional second deflecting means (6l) which forms a second deflecting axis for the second web strand (Bl) and is most immediate to the additional first deflecting means (5l) in the conveying direction (F) of the second web strand (Bl),

    wherein the second web strand (Bl) is offset in parallel by looping around the additional deflecting means (5l, 6l) and the degree of spreading (X; X+Y) is thus completely or partially set.
12. The web spreading device according to the preceding claim, characterised in that at least one of the additional deflecting means (5l, 6l) is mounted in the frame (2) such that it can be adjusted along an adjustment path in order to be able to set the degree of spreading (X; X+Y), and in that the adjustment path of the at least one of the additional deflecting means (5l, 6l) is linear in its entirety or at least in one section and extends in the conveying direction (F) which the second web strand (Bl) exhibits between the additional deflecting means (5l, 6l).
13. The web spreading device according to any one of the preceding two claims, characterised in that the deflecting means (5r', 6r') for at least one (Br) of the web strands point obliquely with respect to the conveying direction (F) of the at least one (Br) of the web strands, at an applying angle (α) in relation to the run-in web strands (Br, Bl) which is greater than 80° and smaller than 90°.
14. The web spreading device according to any one of the preceding three claims, characterised in that the deflecting means (5r', 6r') for the first web strand (Br) each point obliquely with respect to the conveying direction (F) of the run-in first web strand (Br) at a first applying angle (α), and the deflecting means (5l, 6l) for the second web strand (Bl) each point at another angle (β) with respect to the conveying direction (F) of the run-in second web strand (Bl), and in that the first angle (α) and the second angle (β) are not the same.
15. The web spreading device according to the preceding claim, characterised in that the other angle (β) is an applying angle of less than 90°, such that the deflecting means (5l, 6l) for the second web strand (Bl) also point obliquely with respect to the conveying direction (F) of the run-in second web strand (Bl), as viewed in the web plane of the run-in second web strand (Bl).
16. The web spreading device according to any one of claims 11 to 15, characterised in that the at least one adjustably mounted deflecting means (6r; 6r') of the first web strand (Br) can be moved by an adjustment path length relative to the additional deflecting means (5l, 6l) of the second web strand (Bl), such that the strand paths of the web strands (Br, Bl) between the deflecting means (5r, 6r; 5r', 6r') of the first web strand (Br) and between the additional deflecting means (5l, 6l) of the second web strand (Bl) can be set in lengths which deviate from each other.
17. The web spreading device according to any one of the preceding claims, characterised in that at least one (6r, 6l; 6r', 6l) of the deflecting means is supported on the frame (2) at one end only and freely projects from the frame (2) with the other end.
18. The web spreading device according to any one of the preceding claims, characterised in that the spreading device comprises a run-out channelling means (7r) for the first web strand (Br) and an additional run-out channelling means (7l) for the second web strand (Bl), which are mounted in the frame (2) such that they can be moved relative to each other, behind the second deflecting means (6r, 6l; 6r', 6l) in the web conveying direction (F), and in that the run-out channelling means (7r, 71) and the movably mounted second deflecting means (6r, 6l; 6r', 6l) can be moved into adjustment positions in which they jointly determine a plane for each of the web strands (Br, Bl).
19. The web spreading device according to the preceding claim, characterised in that the run-out channelling means (7r) and the second deflecting means (6r; 6r') for the first web strand (Br) are mounted such that they can be jointly moved, and the additional run-out channelling means (7l) and the additional second deflecting means (6l) are also mounted such that they can be jointly moved.
20. The web spreading device according to any one of the preceding claims, characterised in that a control means (15) is provided which comprises a drive means (12) for the at least one adjustably mounted deflecting means (6r, 6l; 6r', 6l) in order to adjust the at least one adjustably mounted deflecting means (6r, 6l; 6r', 6l) into the adjustment position required for setting the degree of spreading (X; X+Y).
21. The web spreading device according to any one of the preceding claims, characterised in that the at least one adjustably mounted deflecting means (6r, 6l; 6r', 6l) projects from a carriage (10r) which is guided on a linear guide (11) of the frame (2).
22. The web spreading device according to any one of the preceding claims, characterised in that a longitudinal cutting means (4) is provided in order to cut a web (B) into the web strands (Br, Bl), and in that the longitudinal cutting means (4) and the deflecting means (5r, 6r, 5l, 6l; 5r', 6r', 5l, 6l) are mounted such that they can be jointly moved relative to the web (B), transverse to the conveying direction (F) of the web (B).
23. The web spreading device according to any one of the preceding claims, characterised in that the web spreading device is used as an actuating member of a web edge controller of at least one of the web strands (Br, Bl).

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