Technical field

T _h e present invention relates to a method for the removal of web material roll wrappers and an apparatus for the application of said method, particularly a method for deheading large material rolls containing a long material web like for example paper for a daily newspaper printing machine, and additionally an apparatus for the deheading of such supply rolls according to said method.

Prior art

Paper for e.g. daily newspaper printing machines is delivered in form of large paper rolls having a considerable width and weight. These paper rolls are inserted into a multi-arm web roll reel at the printing machine for manual or automatic splicing into the running paper web when the previous supply roll starts to become empty.

The paper rolls usually are delivered having a standardized wrapper to protect the relatively thin paper web wound on such a roll. The standardized wrapper consists partly in that the roll, at its envelope surface, is covered by a wider strong paper, a so called drying paper, and partly in that the roll sides are provided with additional separate round heads of strong paper or board. These separate heads consequently have the same diameter as a complete web roll. The portion of the drying paper extending beyond the paper roll gables are folded along the periphery of the roll towards the web roll gable and is glued to the additional separate stronger round paper head, after which at the same time commonly another such paper head is attached to further retain the folded in drying paper and at the same time add to the protection of the roll gable if the roll for example should be put edgeways. In this way a complete wrapper of the paper roll is obtained, and which rolls then may be transported from the paper factory to the users hoping that the relative fragile paper web will not be damaged mechanically or by moisture.

When a paper web roll should be deheaded according to the state

of the art it will be positioned lying on two rotatable rollers by means of which the large and heavy paper web roll may be rotated. This deheading requires according to prior art normally one or two persons. That person or persons is/are first manually inserting a relatively long knife between the two paper heads glued at the periphery and the roll gable. When the knife or knives is/are positioned as indicated above the paper roll is rotated by the rotatable rollers one revolution such that the paper heads are cut loose from the drying paper protecting the envelope surface. Thus the heads will come off the roll which afterwards will be mounted into the multi-arm web roll reel of the printing machine, whereafter usually the roll envelope surface generally is made completely free from the drying paper and provided with some type of splicing flap.

Hereby it is very essential seeing to that no damages are made to the roll gable sides by the knives, as damaging of the paper web edge easily may lead to the breaking of the paper web, especially in printing machines for daily papers, normally working .at a very high speed. A breaking of paper often implies a maybe up to half an hour shut-down of the printing machine, all printing units of which have to be completely stopped. Addition¬ ally further time is consumed before the complete printing machine with all printing units have been accelerated again to the full speed. Besides at each start-up a number of so called starting maculature is obtained, i.e., newspapers being incom¬ plete, which is disposed and which of course increases the printing expenditure.

Consequently the deheading operation above at the same time being partly a hard work also is a resource demanding work to guarantee an unobjectionable paper feeding to a printing machine of this kind.

The documents US-A-5 060 456 and US-A-5 016 429 discloses arrangements for more or less automatic removal of the gable heads of a paper supply roll. The respective knives are moved out

to the edges of the envelope surface wrapper and are then biased against the roll and will cut the wrapper at the roll gable edges and if a gable is slightly deformed due to edgeways transporta¬ tion of the roll, there will be a great risk of damaging the edges of the paper web.

Also the document CH-A 547 205 is disclosing an automatic deheading of such supply rolls, but with knives cutting both at the envelope surface wrapper as well as at the gable heads, which involves the risk of damaging the sensitive paper edges. A similar process is also disclosed by JP-2-269629 having the same drawbacks.

In the Japanese documents JP 63-317431, JP 63-277161, JP 63- 307030, JP 63-232130, JP 20-04627, and JP-2269628 are disclosed technique for more or less automatic deheading of paper rolls, whereby the disclosed technique in all of these cases only relates to deheading by cutting the protective material across the envelope surface of the roll. This means that no specific action is taken to remove an eventual gable head protection why none of these devices will be suitable to solve the problems in removal of the standardized wrapper type referred to above.

Consequently there is a wish to find a method and an apparatus facilitating automatic deheading of such a material web roll having the standardized wrapper as discussed above without risking damages of the paper web edges, especially at the beginning of the web roll as the automatic splicing of a new roll by means of the multi-arm web roll reel involves a critical operation point of the printing machine operation and which normally takes place at the full paper feeding speed of the printing machine in question. By a method facilitating an apparatus for automatic deheading the heavy and trying job, normally demanding one or two persons, should consequently be avoided, this will further, besides a general time gain, result in an essential decrease in production costs.

Description of the invention

An object of the present invention is to provide a method facilitating automatic deheading of a supply roll containing a long web of material without risk of damaging the material web and its edges.

The method according to the present invention involves the forming of at least one engagement lip at the envelope surface of the material web roll in its protecting layer being the envelope surface wrapper, additionally a lifting of the engage¬ ment lip for insertion of at least one knife to cut the envelope surface wrapper layer, and a guiding of the knife or knives such that this or these may not at any occasion come in touch with any of the material web roll gable sides.

Additionally the method according to the invention involves the moving of at least one knife around the material web roll envelope surface adjacent to a gable side but on top of the material web roll envelope surface itself during rotation of the web roll until the knife has cut along all of the protecting material being the envelope surface wrapper, whereby the heads of the gable side adjacent to the knife will be released, and repeating the method for the second supply roll gable side during continued rotation of the supply roll or utilizing at least two knives, at least one being positioned adjacent to a first and a second gable side, respectively, during rotation of the material web roll until the heads of the first and second gable are release .

Another object of the method according to the present invention is to additionally provide pressurized air means for the release of the cut gable heads.

Another further object of the present ^" invention is to provide together with the knife a sensing device by which will be sensed when the wrapper layers on the material web roll ceases and material of another color starts, whereby the rotation of the

material web roll will stop.

Description of the drawings

The invention will be described by means of an embodiment and by means of the attached drawings. In the drawings

Fig. 1 is demonstrating in cross section a view of a material web roll having a standardized packing,

Fig. 2 is demonstrating a simplified view of an apparatus for automatic deheading of material web rolls according to Fig. 1,

Fig. 3 is demonstrating an enlarged detailed view of a knife device according to the present invention,

Fig. 4 is demonstrating a side view of the knife device according to Fig. 3,

Fig. 5 is demonstrating the cutting pattern on a material web roll when all of the wrapper should be removed accor¬ ding to the present invention,

Fig. 6 is demonstrating the cutting pattern when only the gable heads should be removed according to the present invention, and

Fig. 7 is demonstrating a material web roll according to Fig. 1, where pressurized air nozzles are used to further assist the removal of the roll gables.

Detailed description of embodiments

In Fig. 1 is shown i cross section a material web roll 1 containing a long material web 2. The web roll 1 is on its envelope surface provided with a wrapper 6, e.g., of drying paper. Additionally the roll is provided with separate heads 5 and 7 at the respective web roll side gable. The wrapper layer

6 on the web roll envelope surface is slightly wider than the material web 2 and is because of that folded in towards the roll gables and preferably glued between the disc like separate heads 5 and 7. The material web 2 is further wound on a central spool 3 provided with mounting means 4 for mounting shafts when unwinding the material web 2.

Figure 2 is schematically demonstrating an apparatus for automatic deheading of the web roll 1. The apparatus consists of a frame 8 in which the web roll is positioned by means of a conveyor 9 or the like. The apparatus further comprises two rotatable rollers 10 against which the web roll 1 is resting within the apparatus. In the upper portion of the apparatus there is a device 11 to, among other things, form an engagement lip in the wrapper envelope surface 6. Additionally the device 11 is provided with further means to raise the engagement lip and to introduce a knife or several knives for the cutting of the wrapper, which will be explained in detail below.

In a first preferred embodiment the apparatus is provided with two knife devices 20, in figure 3 shown in a plane top projec¬ tion. The apparatus according to the first embodiment concerns a complete deheading of the web roll 1, which may be a paper roll for newsprint, before it will be inserted into a multi-arm web roll reel of, e.g., a printing machine for daily newspapers. The multi-arm web roll reel is the used according to prior art for manual or automatic splicing of web of a new roll into the running paper web.

By the device 11 a preferably semicircular flap 13 in the web roll 1 wrapper envelope surface 6 is cut by a first knife (not shown). In the preferred embodiment the device 11 comprises among other things a semicircular punch 12 in the center of which there is a vacuum means in form of a circular channel discharging approximately central in the punch. When the punch according to known technique by electric, hydraulic or pneumatic guiding has created the semicircular engagement lip 13 it lies close to the

wrapper at the envelope surface of the web roll 1. The channel opening of the vacuum means thus lies close to a surface 18 of the engagement lip 13 and when the punch again is raised somewhat the engagement lip or the flap 13 will be retained by the vacuum means and will thereby be raised somewhat, creating a gap in the wrapper where the knives 20 are inserted, which is schematically demonstrated in Figure 3.

Figure 4 demonstrates in a side view an embodiment of the knife device 20 for cutting the wrapper of the web roll 1. The knife device 20 consists of a circular knife 21 resting against a resilient support guide 23. The resilient support guide 23 is slightly bent corresponding to the bending of the envelope surface of the web roll 1. Additionally in the embodiment a free end of the resilient support guide is provided with a rounded top 24 to follow the envelope surface of the web roll 1 being deheaded. The circular knife 21 is attached to a shaft in a mounting 22 which is integrated with the resilient support guide 23. The mounting 22 is further through a linkage 26 connected to the device 11 via a guiding arm 25, the movement of which being controlled by the device 11 having electrical controlling means (not shown). The controlling means may of course in another embodiment be hydraulically or pneumatically controlled.

Assisted by Figure 5 and the Figures 2 and 3 the course of events when performing deheading may be described more in detail. When the punch by means of the vacuum means has raised the engagement lip 13 the two knife devices 20 with their support guides 23 are inserted through the flap formed at 13. The wrapper then will be pinched between the circular knife 21 and the support guide 23, why the circular knife will be cutting the wrapper when the material web roll 1 is rotated within the frame 8 by the rotatable rollers 10 in a direction marked by an arrow A. Simultaneously as the web roll is rotated and the knife devices 20 start cutting the wrapper, the knives are moved outward along the dashed lines in Figure 5 due to that the knife devices 20 first by the control device 11 (not shown) are twisted somewhat

outwards by means of the linkage 26. When the web roll 1 starts to rotate the underpressure of the vacuum means is removed whereby the engagement lip automatically is released from the vacuum means. When the knife devices 20 have arrived to a position about 1 to 2 cm from the web roll edge the circular knives 21 are restored to be parallel to the web roll end surfaces to thereafter be cutting the wrapper layer by layer during the continued rotation of the web roll 1. When the circular knives 21 have been cutting through all of the envelope surface wrapper, the heads will fall off as these then will be completely released from the envelope surface. Simultaneously as the web roll being rotated the wrapper of the envelope surface will be fed away and will in the preferred embodiment be going directly to a paper chipping (not shown) in immediate association to the frame 8. In a similar way the heads are also discarded when they are released.

If it for the moment is desirable to keep the envelope surface wrapper and only remove the heads this is executed by first according to Figure 6 create engagement lips 13a and 13b at the envelope surface adjacent to the gables and in the same way as above the knife devices 20 are inserted and the web roll 1 rotated until gable side heads have been released. As no cut has been done across the envelope surface the envelope surface wrapper 6 will stay for later removal, e.g., after that the web roll 1 has been positioned into a multi-arm web roll reel. Thus the dashed lines in Figures 5 and 6 demonstrate the different tracks of the circular knives 21 on the envelope surface. As the device 11 does not permit the knives 21 to be positioned closer than 1 to 2 cm to the envelope surface edge, there is no risk for any damaging of the material web edges contrary to deheading according to prior art when knives were inserted against the gable sides.

When several engagement lips are to be created this is done in the preferred embodiment by using two punches having their own vacuum means for the raising of the created flaps. Anyhow the

invention may be practiced in another embodiment having only one punch which is moved between the two positions of the flaps 13a and 13b. The positions of the flaps 13a and 13b will then normally not be completely parallel on the envelope surface as one, e.g., engagement lip 13a is created first and a first knife device 20 in inserted into this, after which the second engage¬ ment lip 13b is created and a second knife device 20 is inserted into that.

In the simplest embodiment according to the invention there is only one punch and one knife 20, whereby first the heads of one gable are cut free and thereafter the others. In the embodiment discussed the first knife in form of a punch and the vacuum means are integrated. If the first knife constitutes some other type of cutting device the vacuum means may preferably be a separate device for the raising of the engagement flap created in this way.

Additionally in the preferred embodiment each knife device 20 is at the resilient support guide provided with an optical sensor device sensing when the wrapper on the envelope surface ends and is replaced by, e.g., white paper. The optical sensing device controls according to known technique the apparatus such that the rotatable rollers in the frame 8 stops rotating when the sensors indicate that the knife devices have passed through all of the wrapper which normally contains drying paper having another color than the web material of the web roll 1.

Additionally the preferred embodiment is further provided with one or two pressurized air means 16 penetrating the heads 5 and 7 at one mounting means 4 or both mounting means 4 of the web roll 1 and applying overpressure in the central spool of the web roll, whereby the heads 5 and 7 will be pressed out from the sides of the web roll 1 and are more easy released from the roll sides when the cut along the envelope surface periphery has been performed.