EP1752402A1 - Device for threading webs - Google Patents

Abstract

Device for guiding a material between two positions comprises an auxiliary unit (21) having a tube (30) which encloses an inner chamber impinged with a low pressure. The tube has a planar outer surface (44) on a part of its periphery through which is guided a suction opening arrangement having a suction opening up to the inner chamber. Preferred Features: The tube is held by supports (41, 42) at both ends. One support (41) has a rotary drive (43) acting on the tube. The tube has a curved casing with an opening receiving an insert.

Description

The invention relates to a device for guiding a web from a first position to a second position, in particular from an unwinding station to a winding section of a reel winder, with an auxiliary device which engages the web at the first full-width position.

The invention will be described below using the example of a reel winder. Here, a web, in particular a paper web, withdrawn from a supply roll, passed through a longitudinal cutting device and then fed to a winding section, where the then present in partial webs web is wound on partial web rolls. These partial web rolls can be wound, for example, in a double take-up roll winder or in a support or contact roll winder.

At least during initial commissioning, but usually also in certain business interruptions, the web must be guided from the unwinding station to the winding section.

For this so-called threading or insertion process, it is customary to provide the web with a point, ie with a section which has a substantially smaller width than the web itself. Although such a tip is much easier to handle than the web in full width. But it has the disadvantage that a not negligible part of the track is lost. In particular, one can not enter the longitudinal cutting knife into the web until the web has arrived at the winding section with full width.

One has therefore in the older one German patent application 10 2004 049 720 proposed to detect the web with an auxiliary device and then to guide the auxiliary device along the predetermined path. For this purpose, it is necessary that the auxiliary device can detect the web over its full width.

The invention has for its object to easily detect a web in the region of its beginning in full width.

This object is achieved in a device of the type mentioned above in that the auxiliary device comprises a tube which encloses an interior, which is acted upon by negative pressure, wherein the tube has on a part of its circumference a flat outer surface through which a Saugöffnungsanordnung with at least a suction opening is led to the interior.

This embodiment has several advantages. The auxiliary device is inexpensive to manufacture as a pipe. In the tube is the interior, in which the negative pressure can spread evenly across the width of the web available. The fact that the tube has a flattened outer side, there is a substantially flat surface on which the web can be firmly sucked. In this Flat surface can be accommodated accordingly relatively large suction openings, so that the web can be applied over a correspondingly large area with negative pressure. The web does not have to deform in the system at the auxiliary device. This keeps the risk of damage small. Moreover, the suction forces applied to the web via the suction opening assembly can be fully utilized to hold the web. If the flat outer surface is parallel to the web, then gaps between the web and the outer surface can be avoided. Compared with a tube having a cylindrical cross-section, significantly improved holding forces result.

Preferably, the tube is held at both ends in each case a carrier. So you can decouple the function of the tube to hold the track, and decouple the transport properties. The tube is used exclusively for the temporary attachment of the track. The guidance of the tube along the path of movement is then taken over by the carriers. Accordingly, it is sufficient to use the tube in the carrier. Further processing of the pipe is not required. Preferably, at least one carrier has a rotary drive acting on the tube. This makes it possible to put the tube with sucked web start in rotation, so that the web start is wound one or more times around the pipe. The forces required to move the web along the trajectory between the first position and the second position then no longer have to be applied exclusively via the negative pressure become. The vacuum rather serves to hold the beginning of the web during winding on the pipe. By winding forces then arise in the manner of a rope friction, which in any case sufficient to pull the web along the trajectory.

Preferably, the tube has a curved shell with an opening into which an insert with a flat contact surface is inserted. This facilitates the production on the one hand. It is possible to use as shell a half-shell or a shell which extends over a correspondingly larger or smaller circumferential angle. Such a shell can be easily bent from a sheet or cut from a tube semi-finished. In the existing or emerging opening the insert can be used. It is then possible to design the insert exclusively for cooperation with the web, in particular in view of the fact that the web should not be damaged when sucked to the auxiliary device.

Preferably, the insert projects beyond the edge of the opening. The insert thus covers the rest of the tube so far that the web comes into contact with the tube only insofar as it is wound around the circumference of the tube. One avoids, however, that possibly sharp edges of the tube remain at the transition from the flat surface in a curved area, which could damage the web. Although it is not critical if the beginning of the train is no longer usable later. This beginning will be in most cases not used anyway. However, damage involves the risk that the web will tear off when pulled. This is avoided if the insert is large enough and free of sharp edges.

It is also preferred that the insert is formed of a plastic. A plastic is arbitrarily malleable in many areas. So you can easily adapt it to the required requirements. In particular, in a plastic, which is usually softer than a metal, there is less risk of damage to the web when pulling.

It is also advantageous that a sealing arrangement is arranged in the region of the suction opening. Such a sealing arrangement may be formed of an elastic material, which is formed for example moss rubber-like. If a seal arrangement is present, then the web can better conform to the auxiliary device. The air loss during suction is lower.

Alternatively or additionally, it may be provided that the flat outer surface has a lower roughness than the curved portion of the outer surface. The contact surface, which is formed by the flat outer surface, may be ground, for example. This also reduces the loss of air when the web is sucked once.

Preferably, the auxiliary device cooperates with a pressure device. Such a pressure device presses the web against the flat contact surface. Thereafter, the negative pressure can be generated. Especially with heavier webs, so webs with a larger basis weight, such as cardboard sheets, it is achieved so that the negative pressure holds the web securely to the auxiliary device.

It is also advantageous if the Saugöffnungsanordnung has a variable effective width. In this case, one can adjust the width of the Saugöffnungsanordnung to the width of the web. There remain at a narrower track no open suction, which could interfere with the build-up of a negative pressure in the interior.

Fig. 1

eine Rollenwickeleinrichtung in schematischer Darstellung,

Fig. 2

eine schematische Darstellung einer abgewandelten Ausführungsform einer Hilfseinrichtung neben einer Jumborolle,

Fig. 3

einen schematischen Schnitt durch ein Rohr,

Fig.4

eine abgewandelte Ausführungsform der Hilfseinrichtung und

Fig. 5

eine Draufsicht auf das Rohr von der abgeflachten Seite her.

The invention will be described below with reference to preferred embodiments in conjunction with the drawings. Herein show:

Fig. 1

a roller winding device in a schematic representation,

Fig. 2

a schematic representation of a modified embodiment of an auxiliary device next to a jumbo roll,

Fig. 3

a schematic section through a pipe,

Figure 4

a modified embodiment of the auxiliary device and

Fig. 5

a plan view of the tube from the flattened side.

Fig. 1 shows a schematic representation of a roll winding device 1 with an unwinding station 2 and a winding station 3. Between the unwinding station 2 and the winding station 3, a longitudinal cutting device 4 is arranged.

In the unwinding station 2 an unwinding position 5 is provided. In the unwinding position 5 is a pay-off bearing 6, in which a spool 7 is rotatably mounted. On the spool 7, a master roll 8 aufgewikkelt, of which a remainder is still visible in Fig. 1. From the parent roll 8, which may also be referred to as a "jumbo roll", a web 9 is withdrawn. This web 9 is cut in the slitter 4 in several sub-webs and wound in the winding station 3 to several bobbins 10, of which in Fig. 1, only one can be seen because these bobbins 10 are in a direction perpendicular to the plane behind the other.

The unwinding 6 is suitable for higher speeds. For example, the web 9 can be withdrawn at a speed of 2000 to 3000 m / min. On the opposite side of the main cylinder 7 of course a similar Abwickellager 6 is arranged.

The winding rollers 10 rest on two support rollers 11, 12, of which at least one is driven. A loading roller 13 may be provided to control the winding process. Instead of the illustrated so-called "Doppeltragwalzenwicklers" may also be provided a back-up roll winder, in which the winding rollers 10 are held centrally and bear against a support or contact roller.

The unwinding station 2 also has a preparation position 14, in which a further reel 15 with a new master reel 16 is kept ready. The preparation position has a preparation bearing 17, which also allows a rotation of the main cylinder 15, but is less expensive, because the necessary rotation speeds are much lower. The preparation bearing 17 and the unwinding bearing 6 are interconnected by a track 18 on which the spool 15 in the preparation position 14 to the unwinding position 5 can roll when a reel change is required.

In the preparation position 14, the mother roll 16 is prepared. As a rule, some layers of the web are handled and disposed of in preparation. This process is also referred to as "stalling". For receiving the portion of the web 9 to be disposed of, a pulper opening 19 is provided, which is arranged below the preparation position 14 in such a way that under the action of gravity hanging down web 9 hits the pulper opening 19. Because the mother role 16 does not always have the same radius, the position of the drooping web 9 will move slightly. However, the pulper opening 19 is so large that it can catch the falling web. Optionally, a hopper 20 may be additionally provided.

It is now occasionally necessary to guide the web 9 from the unwinding station 2 to the winding station 3. The web 9 must also be guided by the longitudinal cutting device 4. This process is also referred to as "inserting."

For insertion, the roll winding device 1 an auxiliary device 21, which is shown in Fig. 1 at different positions. In different positions, the auxiliary device 21 is provided with small letters (a, b, c) for distinction.

The auxiliary device 21 is guided on a movement path 22, which is shown as a dashed line. The trajectory is realized by rails or guides, which are arranged on both sides of the web 9 outside its width. Along the movement path 22, a chain, a belt or a rope can be performed, these devices are driven in a manner not shown by a common drive, so that the auxiliary device 21 in an orientation perpendicular to the direction of movement of the web 9 of the unwinding station. 2 can be performed to Aufwickelstation 3.

The auxiliary device 21 is now moved from the left (relative to the illustration of Fig. 1) to the under the action of gravity vertically hanging down web 9 and attached to the web.

2 and 3 show an auxiliary device 21 in an embodiment which differs slightly from the illustration of FIG. 1. The auxiliary device 21 is namely driven from the other side against the web 9. In addition, the auxiliary device 21 detects the web 9 in the area of the jumbo roll 16. Otherwise, however, the auxiliary device 21 is in principle just as usable as in the embodiment according to FIG. 1.

Fig. 3 shows the auxiliary device 21 in cross section. The auxiliary device 21 has a tube 30 which surrounds an inner space 31. The tube 30 is formed from a half-shell 32 into which an insert 33 is inserted. The half-shell 32 engages in grooves 34 which are formed on the two longitudinal sides of the insert 33.

The insert 33 is slightly up and down on the half-shell 32, so that it covers the end face of the half-shell 32, so to speak, completely. The insert 33 has a height which corresponds approximately to the diameter of the tube 30, if this had a completely circular cross-section.

In the insert 33 a plurality of suction openings 35 are formed. If now the interior 31 with a negative pressure is acted upon, then this negative pressure acts on the suction ports 35 to the outside. Now, if the web 9 rests against the outside of the insert 33, then it is sucked through the suction openings 35 on the insert 33 and thus on the tube 30.
As can be seen from the right half of FIG. 5, one can surround the suction openings 35, each with a seal 36. This seal 36 is formed of an elastomeric material. It can for example be formed mousse-like.

In the left half of Fig. 5, the suction openings 35 are not surrounded by a seal. It is also possible to provide the surface of the insert 33 with increased smoothness, for example by grinding, so that the web 9 rests smoothly and no gaps are created through which air could penetrate into the interior 31.

Of course, you will make all the suction ports 35 uniform, so either all suction ports 35 provided with a seal 36 or the entire surface of the insert 33 provided with a higher smoothness.

You can now use the jumbo 16 as it were as an abutment to press the web 9 against the contact surface on the insert 33. For this purpose, then the auxiliary device 21 is to be arranged approximately at the height of the axis of the jumbo roll 16.

If this is not possible, one can, as shown in Fig. 4, an auxiliary device 21 with a Allow pressure device 37 to interact. The pressure device 37 has a punch 38, which can be displaced under the action of a drive 39 in the direction of a double arrow 40, ie in the direction of the auxiliary device 21 to or away from it. You can then use the punch 38 to press the web 9 against the insert 33.
The tube 30 is mounted at its two ends in carriers 41, 42. The one carrier 42 is shown in dashed lines, so as not to obscure the view of other elements of FIG.

The carriers 41, 42 are then movable along the movement path 22.

The tube 30 is rotatably mounted in the carriers 41, 42. The carrier 41 has a rotational drive 43 shown only schematically, with which the tube 30 can be rotated to wind the web 9. Thus, if the web 9 has been firmly sucked on the contact surface 44 of the auxiliary device 21, then the suction force is sufficient to hold the web 9 during the winding on the tube 30 on the pipe 30. Once the tube 30 has made one or more revolutions behind it, the web 9 is fixed to the auxiliary device 21 with the necessary frictional force.

As can be seen from FIG. 1, in the area of the auxiliary device 21 a cross-cutting device 23 can still be provided which separates a section 24 of the web 9, which then falls into the pulper opening 19. If only a short piece of the web 9 projects down over the auxiliary device 21, then it is easier to wind the web 9 on the auxiliary device 21.

As can be seen from Fig. 2, the auxiliary device 21 has a width which is greater than the width of the web 9. The tube 30 is thus at the two longitudinal edges of the web 9 slightly over the web 9 on. The supernatant does not have to be large. But it should be sufficient to prevent a conflict between the web 9 and the two carriers 41, 42. This also applies if the carriers 41, 42, which are shown only schematically in FIG. 2, are made smaller.

As can be seen from FIG. 5, 30 partition walls 45, 46 are provided within the tube, which can be displaced in the direction of double arrows 47, 48, ie parallel to the width extension of the web 9. This makes it possible to separate individual suction openings of the inner space 31, so that these suction openings 35 are no longer sucked. By this measure, it is therefore possible to adapt the effective width of the suction opening arrangement formed by the suction openings 35 to the width of the web 9.

An alternative to this is to close the unneeded suction openings 35 by plates.

Claims (10)

Device for guiding a web from a first position to a second position, in particular from an unwinding station to a winding section of a reel-winding device, with an auxiliary device which engages the web at the first full-width position, characterized in that the auxiliary device (21) engages Tube (30) which encloses an inner space (31) which can be acted upon by negative pressure, wherein the tube (30) on a part of its circumference has a flat outer surface (44), through which a Saugöffnungsanordnung with at least one suction opening (35) is guided to the interior (31). Apparatus according to claim 1, characterized in that the tube (30) is held at both ends in a respective carrier (41, 42). Device according to claim 2, characterized in that at least one carrier (41) has a rotary drive (43) acting on the tube (30). Device according to one of claims 1 to 3, characterized in that the tube (30) has a curved jacket (32) with an opening, in which an insert (33) with a flat contact surface (44) is inserted. Apparatus according to claim 4, characterized in that the insert (33) projects beyond the edge of the opening. Apparatus according to claim 4 or 5, characterized in that the insert (33) is formed from a plastic. Device according to one of claims 1 to 6, characterized in that a sealing arrangement (36) is arranged in the region of the suction opening (35). Device according to one of claims 1 to 6, characterized in that the flat outer surface (44) has a lower roughness than the curved portion of the outer surface. Device according to one of claims 1 to 8, characterized in that the auxiliary device (21) cooperates with a pressure device (37). Device according to one of claims 1 to 9, characterized in that the Saugöffnungsanordnung has a variable effective width.

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