WO2008097172A1

WO2008097172A1 - Method and machine for rewinding a web material and attachment unit to be used in the method

Info

Publication number: WO2008097172A1
Application number: PCT/SE2008/050067
Authority: WO
Inventors: Bengt ANDRÉASSON
Original assignee: Trancel Restatic Aktiebolag
Priority date: 2007-02-09
Filing date: 2008-01-22
Publication date: 2008-08-14
Also published as: SE0700324L; SE529861C2

Abstract

The invention concerns a method relating to cutting off sections of a web material (85b) in a slitter rewinder (20) in order successively to form a plurality of rolls. In the machine the web material is unwound on sleeves (91) which are prepared in advance with double-stick adhering attachment units (1, 1') which are fastened on the sleeves, before the sleeves are mounted on a spindle (30') which has been drawn out sideways from the machine. The spindle is then brought into the machine again to be rotated at the same time as the web material is pressed against the adhering upper surfaces (7,9) of the attachment units, such that front and rear attachment unit portions (4,5) adhere to the underside of the web material. The web material and the attachment units are cut off along a transversal line between the front and rear attachment unit portions. The rear attachment unit portion remains on the sleeve, on which a new web section begins being unwound, while the trailing end (85b') of the nearly completely unwound section finally is secured to the completed roll (75) by means of the front attachment unit portion, which was not permanently attached to the sleeve. The invention also concerns the said machine (20), said attachment unit, and an assembly (100) of attachment units.

Description

METHOD AND MACHINE FOR REWINDING A WEB MATERIAL AND ATTACHMENT UNIT TO BE USED IN THE METHOD

TECHNICAL FIELD

The invention relates to a method in which a web material is cut into sections, which are rewound in order successively to form a plurality of rolls, particularly a method in which a web material is slit up into a large number of narrow strips, which are cut into sections which are rewound to form rolls. The invention also concerns a machine for the carrying out of the method for cutting off and successively rewinding sections of the web material on sleeves in order successively to form a plurality of rolls. Further, the invention relates to an attachment unit intended for fastening the trailing end of the cut off section to the surface of a nearly completed roll and for fastening the leading end of a new section to a new sleeve intended to receive the new section to be rewound, and the invention also relates to an assembly containing a large number of such attachment units.

BACKGROUND OF THE INVENTION

Machines of the kind mentioned in the preamble are usually termed slitter rewinders. The normal practise in machines of that type is, after a wider web material has been slitted into narrower strips, that said strips are cut into sections which are rewound on sleeves. The number of parallel strips and sleeves may be considerable, e.g. 20 to 30 strips and sleeves, respectively. When the rolls are completed, the web material, i.e. the strips, has to be cut off and new sections be rewound on new sleeves. These steps comprise steps which need to be performed manually according to conventional, contemporary technique. It is true that the cutting off of the web material can be performed in a rational mode by means of a knife which is included as an element in the machine, but the fastening of the leading ends of the new strips is normally performed manually. For this purpose, e.g. a piece of double- stick tape is stuck to each sleeve that has been mounted in the machine. This work is cumbersome, particularly when the number of sleeves is great, and prolongs the standstills of the machine when new sleeves shall be mounted. Moreover, the trailing ends on the completed rolls need to be fastened. It is true that this can be carried out at the same time as the new sections are rewound on the new sleeves, but because the work is manual it is difficult to guarantee a good accuracy and a repeatedly perfect appearance of the finished rolls. DISCLOSURE OF THE INVENTION

It is the incentive of invention to address the above mentioned problems and to suggest a method which can reduce the standstill time of the machine in connection with change of sleeves. The method is based on prepreparation of the sleeves, so that their preparation need not be carried out in the machine but can be made in advance by the side of the machine. For example, a great number of sleeves may be prepared in advance and be kept ready in a sleeve store at the side of the machine.

The invention also employs the use of attachment units adapted to the method and a machine which also is adapted to the method and to the use of said attachment units.

According to the invention, the method comprises the following series of steps, which is initiated at the latest when a roll is nearly completed: that the section of web material in question which shall be rewound on a sleeve intended for that section, is connected to said sleeve via at least one attachment unit, said attachment unit being provided with a front portion with a front-upper and a front-lower adhesive surface in front of a conceived cutting line, and a rear portion with a rear-upper and a rear-lower adhesive surface at the rear of the cutting line, such that the front-upper and the rear-upper adhesive surface of the attachment unit is fastened to the web material in front of and at the rear of said cutting line, respectively, and such that the rear-lower adhesive surface is fastened to the sleeve; that the front-lower adhesive surface is prevented from being permanently fastened to the sleeve by means of a release agent provided between the front-lower adhesive surface and the sleeve; - that the web material and an optional connection between the front and rear portions of the attachment unit are cut off along said cutting line; that the trailing end of the nearly completed roll is pulled off from the sleeve, whereby the front portion of the attachment unit comes along, attached on the trailing end, whereupon the rewinding of also the trailing end is completed and the trailing end is fastened to the surface of the underlying web material by means of the upper and lower adhesive surfaces of the front portion of the attachment unit; and that web material is rewound on the new sleeve through rotation of the sleeve, the front end of the new web material remaining fastened to the sleeve by means of the rear portion of the attachment unit.

Although the invention has been developed in the first place for solving above mentioned problems relating to slitter rewinders, it can be applied also in connection with other machines where a web material shall be cut off into several sections which shall be unwound on sleeves without first being slot into narrower strips. In that case, the total number of sleeves is quite limited. The most important advantages of the invention, however, is gained in connection with roller rewinders, where the number of sleeves is great and, consequently, the problems in connection with changes of sleeves are most cumbersome, when conventional technique is employed. Even though sleeves have been referred to in plural form in this text, it should be understood that the claimed patent protection includes also the case when the number of sleeves on each occasion of change of sleeves is only one.

According to a preferred embodiment of the invention, the attachment units are fastened on the respective sleeves before the web material is connected to the respective attachment unit. Among the manual measurements which have a detrimental influence upon the working capacity of the machine, the mounting of the preprepared sleeves on a spindle in the machine is what in prior art machines probably is the most cumbersome measurement. Once the sleeves have been mounted, however, the rest can be performed automatically; attaching the web material to the sleeves by means of said attachment units, cutting off the web material, securing the trailing end of the completed rolls to the outside of the rolls, and unwinding web material on the new sleeves until the new rolls have been nearly completed, provided the attachment units are conveniently designed. The invention therefore aims at providing advantageously designed attachment units and also to simplify the mounting and hence make a quicker mounting of the sleeves in the machine possible.

In the case the machine has two, alternately working spindles, the spindle which is not in operation is preprepared during its non-operating period, which means that it is provided with sleeves and attachment units. At change of rolls, the spindles change position, e.g. by turning them around on a revolving carrier, which may further reduce the necessary time for performing the change of roll operation.

One may, as a modification of the method of the invention, also consider first to apply the attachment units on the web material, which normally is slot into a plurality of strips, and then connect the sleeves to the web material, which is slot into strips, prior to cutting the web material.

The machine is, according to a preferred embodiment of the invention, characterized in that it comprises at least one spindle on which one or more sleeves can be mounted in a sleeve mounting station, that turning devices are provided for turning the spindle with the sleeve or sleeves mounted thereon to a web material attachment position, in which a first pressure roller is provided to press the web material, as the web material is advanced between the first pressure roller and the sleeve/sleeves, against said sleeve/sleeves and against front and rear attachment unit portions, which are mounted in advance on the sleeve/sleeves and provided with adhesive surfaces such that the attachment unit portions will connect the web material to said sleeve or sleeves, and that said turning devices are provided to turn the spindle and the sleeve/sleeves further on and to synchronously advance the web material to a cutting station in which web cutting means are provided to cut off the web material between said front and rear attachment unit portions and also to cut off any connections which may exist between the front and rear attachment unit portions in addition to the web material itself.

The invention also concerns, as has been mentioned above, attachment units which may be employed in connection with unwinding web materials upon sleeves, including cutting off sections of web material, securing the leading end of a new section of web material to a new sleeve and securing the trailing end of a completed roll to the surface of the roll. The attachment units for these purposes include a front portion having upper and lower adhesive surfaces and, under the lower adhesive surface of the front portion, a covering sheet with a lower adhesive surface, and a rear portion with upper and lower adhesive surfaces, wherein the invention is characterized in that said adhesive surfaces have equally good adhesive capacities, but that the upper surface of the covering sheet has such feature that the adherence of the covering sheet to the lower adhesive surface of the front portion is significantly impaired and/or that a release agent is provided between the lower adherence surface of the front portion and the covering sheet in order significantly to impair the adherence between the covering sheet and the lower adherence surface of the front attachment unit portion.

The attachment units may include, between the upper and lower adhesive surfaces, a well defined central layer of for example paper. The central layer may also be more or less fictitious and be integrated with the adhesive surfaces, as may be the case if the upper and lower adhesive surfaces are surfaces of a polymeric sheet material having such pronounced adhesive capacity that the sheet may be regarded as a single layer of adhesive substance.

Further characteristic features and aspects of the invention will be apparent from the dependent patent claims and from the following, detailed description of the invention. BRIEF DESCRIPTION OF DRAWINGS

In the following, detailed description of the invention, a few embodiments will be described with reference to the accompanying drawings, in which Fig. 1 shows a section of an assembly comprising a plurality of attachment units according to a first and to a second embodiment of the invention in a conceived condition of delivery from the manufacturer, mounted on a carrier and provided with a protective sheet, Fig. 2 shows an attachment unit according to the first embodiment, at an exaggerated scale in the thickness direction, in cross-section along the line A-A in Fig. 1, Fig. 3 shows, in a corresponding way, a cross-section through an attachment unit according to the second embodiment of the invention along the line A-A in Fig. 1. Fig. 4 shows, in a side elevation, the main parts of a machine according to a first preferred embodiment of the invention,

Fig. 5 illustrates, in a view in the direction of the arrow B in Fig. 4, a change of sleeves, and devices in the machine which are employed for a lateral displacement of a spindle in connection with the change of sleeves, Fig. 6 shows a section of the machine from the same side as Fig. 4, illustrating the state when a new sleeve just has been entered on a spindle in the machine, Fig. 7 shows the machine in the sleeve's position for the attachment of those attachment members which are included in the attachment units, the cutting off of web material as well as the connections between the front and rear portions of the attachment units, and the separation of the front portion of the attachment unit from the sleeve in question, and

Fig. 8 shows, partly schematically, and at an exaggerated scale, a detail of Fig. 7, illustrating the just mentioned attachment, cutting off, and separation operations.

In the drawings, in the first place elements which are closely connected to the principles of the present invention have been disclosed, while other elements have been omitted in order that those parts which are significant for the understanding of the principles of the invention shall appear more clear. This is particularly true as far as those drawings are concerned, which show the machine.

DETAILED DESCRIPTION OF THE INVENTION

With reference first to Fig. 1, an assembly of attachment units 1, 1', mounted on a strip shaped carrier 2 of release-paper, is generally designated 100. Each attachment unit is covered by a protective sheet 3 which also is made of release-paper. The assembly 100 may form a roll provided in a conveniently designed dispenser-container. The assembly may, in a modified design, also have the shape of e.g. a sheet covered by a major number of attachment units 1, 1', in which case a great number of such sheet shaped assemblies may be collected in a suitable container.

The attachment unit 1, Fig. 2, includes attachment members, which according to the embodiment include a front portion 4 and a rear portion 5 between the carrier 2 and the protective sheet 3. In the attachment unit 1 a central layer 6, which is common for the front and rear portions 4,5, extends between said front and rear portions 4,5. In the front portion 4 an upper adhesive surface is designated 7 and a lower adhesive surface is designated 8, and in the rear attachment unit portion 5 there is in a corresponding way an upper adhesive attachment surface 9 and a lower adhesive attachment surface 10. Between the front attachment unit portion 4 and the carrier/release-paper 2 there is provided a covering layer 12 having a lower attachment surface 13, which contacts the carrier 2. The upper surface of the covering layer 12 has release-features. It may for example be prepared with silicon or similar material, which makes the adherence between the lower attachment surface 8 and the covering layer 12 comparatively weak. As the carrier 2 consists of a release-material, the entire attachment unit 1 may be pulled away from the carrier 2, with the protective sheet 3 remaining stuck, when the attachment unit shall be fastened to a sleeve. In order to make the release of the protective sheet 3 from the carrier 2 more easy, when the attachment unit 1 has been mounted on a sleeve, the protective sheet may have a pull tag 15 in one end thereof.

In the embodiment shown in Fig. 2, the central layer of the attachment unit 1 extends between the front and rear attachment unit portions 4, 5 in the form of a connecting portion designated 16. It is also possible completely to omit the connection portion 16 between the front and rear attachment unit portions, as is exemplified by the second embodiment of the attachment unit, which is designated 1' in Fig. 3. In this case the protective sheet 3 serves also as a connecting element between the front and rear attachment unit portions, when the attachment unit, which remains integrated by means of the protective sheet 3, has been released from the carrier 2 in order to be applied to a sleeve.

With reference now to Fig. 4 a slitter re winder according to a preferred embodiment of the machine according to the invention is designated 20. It comprises a rear part 21, a front part 22, and a rail-mounted carriage 23 adjacent to the front part 22. The rear part 21 may have a design which is known per se in connection with roller rewinders and will therefore not be shown or described in detail, especially as those functions which are particularly characteristic for the invention are associated to the front part 22. However, it should be mentioned that in the rear part 22 there is provided a supply roll 25 of web material, which shall be slot and be divided into more narrow strips, which in turn shall be cut off into sections and be unwound on sleeves and form new, smaller rolls. The machine 20 has a stand 26 which is common for the rear and front parts 21 and 21, and left and right, double walled side frames 27 and 28, respectively, Fig. 5. A rear spindle 29 carrying the supply roll 25 is provided in the rear part 21, and a front spindle 30 is provided in the front part 22. On the front spindle 30 those sleeves, on which strip shaped sections of the web material shall be unwound in order to form new rolls 75, are mounted in a mode which shall be explained in the following. The side frames 27, 28 carry in their ends the rear and the front spindles 29 and 30, respectively, and can be tilted about a centre of rotation 36 by means of a pair of hydraulic cylinders 27. A motor 38 on the right hand side of the machine is provided to drive the front spindle 30 via belt driving on both sides of the machine, including cogged belts 38a, 38b, 38c. A brake unit provided for the supply roll 25 is generally designated 44.

The right end portion 30a of the front spindle 30 is in its functional position journalled in a bearing in a bearing housing 31a, which is connected to the side frame 29 on the right hand side of the machine, Fig. 5. The opposite (left) end of the spindle 30 is journalled in a bearing housing 31b on a slider 32, which can be moved sideways along a guide bar 33 upon withdrawing a locking rod 45, Fig. 4. A driving motor on the slider 32 is designated 34. The reference numerals of spindle 30, slider 32, and spindle end portion 30a are provided with the symbol ' in the pulled out position of the spindle. The machine 20 is further provided with not shown computer units as well as with appropriate software for controlling automatically working functions of the machine as well as for the machine motor 35 and for a motor on the rail-mounted carriage 23.

A number of elements of significant importance for the functions which according to the invention shall be carried out in connection with mounting sleeves on the spindle, fastening web material to the sleeves, and cutting off the web material, are carried by a couple of arms, including an arm 40 positioned over the side frame 27, Fig. 4. In a corresponding way, an equally designed arm is provided over the side frame 28 on the opposite side of the machine. Said arms, as well as the various elements carried by the two arms between them, are not shown in Fig. 5. The two arms, such as the arm 40, are pivotally mounted in a pair of pillars 41, which extend upwards from the side frames 27, 28. A pair of hydraulic cylinders 42 together with their piston rods extend between the respective side frame 27 or 28 and the respective arm 40 for the provision of the turning movements of the arms about an axis of rotation 43. A knife assembly 46, provided between the front end portions of the amis, comprises a sufficient number of upper and lower slitter knives, which are arranged at a proper distance from one another in a mode which may be known per se, for slitting the web material 85b which is fed from the supply roll 25 to form strips of smaller width. The web material which has passed the knife assembly 46 is designated 85b in order to indicate that it now has a different shape, namely the shape of a plurality of more narrow strips.

With reference now also to Fig. 6, a guide roller is designated 50. The guide roller 50 is rotary in bearings, which are stationary mounted in the front end portions of the two arms 40. A pair of double-armed levers 51, one of which is shown in Fig. 6, can be turned about the same centre of rotation 52 as the guide roller 50. A first pressure roller 53 is rotatable about a centre of rotation 54 in the front ends of the levers 51. The levers 51 together with the first pressure roller 53 can be turned about said axis of rotation 52 by means of a pair of pneumatic cylinders 55 and their respective piston rods 56.

A pair of single-armed levers 59 are journalled in a pair of bearing boxes 60 in the front end of the arms 40, pivotally about a centre of rotation 61. The arms 59 can be pivoted about said centre of rotation 61 by means of a pair of front pneumatic cylinders 62 and piston rods 63 belonging to them. The rear ends of said front pneumatic cylinders 62 are pivotally mounted on said double-armed levers 51 in a position at the rear of the centre of rotation of the arms 52. The mounting points of the piston rods 63 on the arms 59 are positioned as close to the front ends of the arms as is possible in consideration of the functional elements which are provided between the arms 59 in the front ends thereof. The said elements include a cutter assembly 64 at a distance from the front end of the arms 59 and a second pressure roller 65 in the front tip of the arms 59.

The cutter assembly 64 includes a circular cutting knife 70, which is rotationally mounted on a knife carrier 71, which in turn is connected to a hydraulic cylinder 72 of the type in which the piston has no piston rod, known by the manufacturer' s trade name Origa®- cylinder. A nearly completed roll 75 of web material is shown in Fig. 6 and Fig. 7 (a plurality of such rolls 75 of strip-shaped web material are provided against one another), laid-up on two rollers 76, 77 on the carriage 23. The carriage is movable on rails 78, on which the carriage can be moved forwards and backwards by means of not shown motion devices, such as an electric motor with belonging transmission or a hydraulic cylinder of the type having a long cylinder stroke. The rolls 75 can be tipped off the carriage 23 by means of a hydraulic cylinder 79 provided to raise the rear roller 76 by turning a pair of levers 88 about a front centre of rotation 81 for further transportation of the rolls by means of a not shown conveyor.

The method and the functioning of the machine according to the invention will now be explained more in detail with reference first to Fig. 4 and Fig. 6.

When the arms 40 have adopted their upraised position (not necessarily as high as is shown in Fig. 4), or possibly before then, the feeding of web material 85a from the supply roll 25 is stopped. If the arms 40 not have been raised, that is done as soon as the feeding of the web material 85a, 85b has been stopped. Next step is to deliver the nearly completed rolls 75 on the carriage 23. For that purpose the side frames 27, 28 are turned a certain angle of rotation counter-clockwise (with reference to Fig. 4) about the axis of rotation by means of the powerful, rear hydraulic cylinders 37, until the rolls 75 reach the carriage 23, which has been brought to a correct rear position for receiving the rolls. In this situation, the spindle 30 is released by pulling out the locking rod 45. The spindle 30 is drawn out from the sleeves 90 in the roll 75 by means of the driving motor 34 on the slider 32 so far that the distance between the end 30a'on the right hand side of the pulled out spindle 30' and the normal position of the left hand side bearing housing 30b will amount to slightly more than the length of a spindle or slightly more than a length corresponding to the total length of those sleeves that are mounted on the spindle. Then the side frames 27, 28 are turned back to their normal horizontal positions.

When the spindle is maximally pulled out, the operator has plenty of space by the side of the machine, as is shown in Fig. 5, enabling him to place new, preprepared sleeves 91 on the spindle 30, whereupon the spindle is returned to its normal position in the machine 20, which is represented by the position of the spindle 30 in the right hand part of Fig. 5. About twenty sleeves 91 are shown in the drawing, each of them provided with an attachment unit 1, 1'. Often, however, the number of sleeves 91 is considerably larger. Various tools can be employed in order further to facilitate the mounting of the sleeves on the pulled out spindle 30. For example, as a further preparation before the machine is stopped for the sleeve mounting operation, the sleeves, which are intended to be mounted on the spindle, first may be mounted (thread) on a rod or on a light weight tube, which may be oriented in the correct direction as is shown in Fig. 5, which illustrates how the entire set of sleeves are kept assembled by means of an inner rod or tube, which the operator carries in his arms. From that rod or tube, the sleeves 91 may readily be pushed over to the spindle 30. As an alternative, the operator may lay the sleeves on a curved tray, from which they may be pushed over to the spindle. As still another alternative, one may conceive to keep them temporarily assembled by means of a few longitudinal strips of adhesive tape, which are cut off once the sleeves have been mounted on the spindle. Also other appliances of course are conceivable. As soon as the sleeves have been mounted on the spindle, the protective sheets 3 are removed, which is easy done by pulling the tags 15. In principle on may also conceive that the protective sheets 3 are removed before the sleeves are mounted on the spindle in order further to speed up the change of rolls.

Conveniently a large number of sleeves are prepared in advanced and are stored in a storage, assembled as sets on a suitable carrier or are connected by a uniting means, e.g. a rod, a curved tray or the like, or by adhesive tapes, respectively, prepared to be ready to be mounted (thread) on a pulled out spindle. Fig. 5 and Fig. 6 shows a storage of prepared sleeves, in the form of a number of sets of sleeves, which rest on a pair of arms 99, in access to the operator, who easily can grip a set of sleeves from the supply and thread/mount it on the spindle 30', as soon as the spindle has been drawn out, which contributes to further simplify and to speed up the change of rolls.

The preparation of the sleeves which are next to be used means that the operator supplies each of them with one of the attachment units 1, 1', which first is released from its carrier/release-paper 2 included in the assembly 100. The protective sheets 3 are maintained, as mentioned, during the attachment operation and are pulled off not before the attachment units are fixed to the sleeves 91 or after the sleeves have been thread/mounted on the spindle. The position of the sleeves 91 in this position, the "sleeve mounting position" is shown in Fig. 6. Fig. 5 thus in this respect is not quite correct but has nevertheless been chosen because it illustrates that the sleeves are "complete" when they are mounted on the spindle. The correct position is the position shown in Fig. 6. When the attachment units are fastened on each respective sleeve, they adhere with their lower adhesive surfaces, which in this case means the lower adhesive surface 13 of the covering sheet 12 and the lower adhesive surface 10 of the lower attachment unit portion 5. The protective sheet 3, which has release features, has been pulled away from the attachment units 1, 1', SO that the upper adhesive surfaces 7 and 9 of the front and rear attachment unit portions 4 and 5, respectively, are exposed. This, however, has not been shown in Fig. 5 or Fig. 6.

The upper adhesive surfaces 7, 9 on those attachment elements which have been mounted on the sleeves 91 on the spindle 30, and which also are exposed, now shall be fastened to the underside of web material 85b, the web material shall be cut off along the intended cutting line between the front and rear attachment unit portions 4 and, and the front attachment unit portion shall be separated from the sleeve 91. All these steps are, according to the preferred embodiment of the invention, performed automatically in sequence. First, the carriage 23 with the rolls 75 resting on the carriage is moved aside, the arms 40 are lowered by means of the cylinders 42 through pivoting the arms about the centre of rotation 43 of the arms, and the arms 59 with the second pressure roller 65 are folded downwards rearwards by pivoting them about the axis of rotation 61 by means of the cylinders 62, so that the first pressure roller 53 will contact the sleeves 92 on the spindle 30, the cutting assembly 64 be positioned in a position for cutting off the web material 85b, i.e. the strips, and the second pressure roller 65 will contact the surface of the rolls 75 on the carriage 23, the movements of which also form part of the operations for the achievement of said positions of the pressure rollers 53 and 65 and the cutting assembly 64 as shown in Fig. 7. When these positions have been adopted, the rotation of the spindle 30 in counter-clockwise direction with reference to Fig. 7 and Fig. 8 is initiated, at the same time as the rolls 75 are subjected to a certain turning moment in counter-clockwise direction with reference to Fig. 7 by means of a motor provided in the carriage 23 for turning one of the rollers 76 and 77, suitably the front roller 77.

Reference is now made to Fig. 8. As the spindle 30 and the sleeves 91 are turned in the direction, of arrow 92 the attachment units 1, 1' will be pressed against the underside of the web material 85b - one attachment unit against each strip of the web material 85b - in the nip 93 between the first pressure roller 53 and the sleeves 91. Successively as the attachment units 1, 1' pass through the nip 93, the upper adhesive surfaces 7 and 9 adhere to the underside of the respective strip of the web material 85b. When the turning has advanced to the position shown in Fig. 8 it is stopped for a short period of time. The circular cutting knife 70 in this position is in a position which with sufficient accuracy corresponds to the position of the intended cutting line L between the front and rear attachment unit portions 4 and 5. The circular cutting knife 70 now is moved over the entire width of the web material so that all the strips are cut off, whereupon the turning of the spindle 30 and the sleeves 91 is continued as before as well as the pulling in the trailing end 85b' of the web material by means of the said motor on the carriage 23.

Already when the front attachment unit portions 4 begin passing the position of the cutting knife 70, they begin being separated from their covering sheets 12, which remain fastened to the respective sleeve 91 due to the lower adhesive surface 13, the adherence of which is much greater than the former adherence between the lower adhesive surface 8 of the front attachment unit portions and the covering sheets 12, the outsides of which are provided with a suitable release agent, as above mentioned. In other words, the front portions 4 of the attachment units remain fastened to the trailing end 85b'of web material which is unwound on the respective roll 75. The trailing end 85b', including the end portion of the web material with the front portions 4 of the attachment units 1,1' still attached to the underside of the strips/web material, is pressed against the rolls 75 as it passes between the second pressure roller 65 and the rolls 75, so that the very end of each strip of web material is fastened to the outside of the rolls by means of said front portions 4 of the attachment units.

The new section of web material 85b, the underside of the front end of which is fastened against to the rear attachment unit portions 5, which in turn are fixed with their lower adhesive surfaces 10 against the respective new sleeve 91, will, during the further rotation of the spindle 30 carrying the sleeves, be unwound on the sleeves 91.

The arms 59 with the cutting assembly 64 and the second pressure roller 65 are moved back to their normal position, as well as the arms 41 and the side frames 40. In their normal positions, the side frames are horizontal, Fig. 5, while the arms 40 are folded down, such that the first pressure roller 53 will touch the rolls gently. The arms 59 on the other hand are inactive and are directed more or less outwards. The completed rolls 75 are brought away by means of the carriage 23 to be delivered to said conveyor or are deposited on some other receiver.

It should be understood that all steps after the preprepared sleeves 91 have been mounted around the spindle 30, which have been described above, are performed automatically in sequence according to a program which is stored in the computer. Also the continued unwinding of the web material 85b (the strips) on the new sleeves 91 is performed according to said program until the new rolls are nearly completed. At that moment, again, the feeding and unwinding of web material 85a, 85b are discontinued and new sleeves are mounted in the mode which has been described above, before the automatics again takes over the control of the process.

It should also be understood that the invention can be modified within the spirit and scope of its basic principles. This concerns the method as such, but also, and particularly, the machine 20 and the attachment units 1, 1'. For example, it is quite possible to design a machine which can operate completely automatically. In that case it might be more convenient, which has been mentioned in the foregoing, to fasten the attachment members on the underside of the web material in a step which is prior to the sleeve mounting station, wherein the lower adhesive surfaces 13 and 10 will be exposed such that they automatically will adhere to the respective sleeve in the next station of the travel of the web material through the machine. The cutting off operation and the separation of the covering sheet 12 from the front attachment portion 4, however, can also in the completely automatic machine be carried out as has been described in the foregoing.

Claims

PATENT CLAIMS

1. Method relating to cutting off sections of a web material (85b) and rewinding the sections in order successively to form a plurality of rolls (75), c h a r a c t e r i s e d in that it comprises the following steps, which initiated at the latest when a roll is nearly completed: that the section of web material (85b) in question which shall be rewound on a sleeve (91) intended for that section, is connected to said sleeve via at least one attachment unit (1,1'), said attachment unit being provided with a front portion (4) with a front-upper (7) and a front-lower (8) adhesive surface in front of a conceived cutting line (L), and a rear portion (5) with a rear-upper (9) and a rear-lower (10) adhesive surface at the rear of the cutting line, such that the front-upper and the rear-upper adhesive surface of the attachment unit is fastened to the web material in front of and at the rear of said cutting line, respectively, and such that the rear-lower adhesive surface is fastened to the sleeve; that the front-lower adhesive surface is prevented from being permanently fastened to the sleeve by means of a release agent provided between the front-lower adhesive surface and the sleeve; that the web material and an optional connection between the front and rear portions of the attachment unit are cut off along said cutting line; that the trailing end of the nearly completed roll is pulled off from the sleeve, whereby the front portion (4) of the attachment unit comes along, attached on the trailing end (85b'), whereupon the rewinding of also the trailing end is completed and the trailing end is fastened to the surface of the underlying web material by means of the upper and lower adhesive surfaces of the front portion of the attachment unit; and that web material is rewound on the new sleeve through rotation of the sleeve, the front end of the new web material remaining fastened to the sleeve by means of the rear portion of the attachment unit.

2. Method according to claim 1, c h a r a c t e r i s e d in that the attachment units first are fastened to the sleeves, and that the web material then is fastened to the attachment units before the web material is cut off.

3. Method according to claim 1, c h a r a c t e r i s e d in that the attachment units first are fastened on the web material, and that the sleeves then are fastened to the web material, before the web material is cut off.

4. Method according to any of claims 1-3, characterised in that the front and rear portions of the attachment units initially are connected to one another, forming an integrated attachment unit (1,1').

5. Method according to any of claims 1-4, characterised in that it is performed in a machine (20) for slitting a web material (85a) into narrower strips, cutting off the strip shaped web material (85b) into cut off, strip shaped sections of the web material, and rewinding the cut off sections into rolls (75).

6. Method according to claim 5, characterised in that said attachment units are fastened in advance to those sleeves (91) on which new rolls shall be rewound in the machine, such that a lower adhesive surface (13) of a covering layer (12) under said front portion and under the lower adhesive surface (8) of said rear portion (5) will adhere to the sleeve, that the continuous feeding of the web material through the machine is interrupted during the progress of the method, that the sleeves, which have been prepared in advance, are mounted on a spindle (30) in a rotational position of the sleeves referred to as sleeve mounting position, that the spindle with the mounted, prepared sleeves is turned from said sleeve mounting position to and beyond a rotational position of the sleeves referred to as web material attachment position, at the same time as the web material synchronously is moved forwards and is pressed against the sleeves and, when passing the web material attachment position, also against said attachment units, causing the attachment units to fasten to the web material by means of said front-upper (7) and said rear-upper (9) adhering surfaces, that the web material with said attachment units are cut off in a cutting station along a cutting line (L) between said front and rear attachment unit portions (4,5), that the trailing end (85b') of the web material is moved on towards the nearly completed roll, at the same time as new web material starts to be rewound on the new roll, at which the front attachment unit portion (4) is disconnected from the sleeve because of a pulling force exerted on the trailing end and also due to said release agent, and that the trailing end is fastened to the thus completed roll.

7. Method according to claim 6, characterised in that sleeves adopt a rotational position in the cutting station which is different from the rotational position of the web material attachment position.

8. Method according to claim 6 or 7, characterised in that the trailing end of the cut off section of web material, together with the disconnected front portion of the attachment unit in question, are pressed against the nearly completed roll by means of a second pressure roller (65) as the trailing end is being fastened against the completed roll of web material.

9. Method according to claim 6, c h a r a c t e r i s e d in that the spindle is pulled out sideways in the machine in the sleeve mounting position at least a distance corresponding to the length of the spindle, such that a space is created in the machine between the free end of the pulled out spindle, which is turned towards the machine, and the opposite side of the machine, in or from which space the sleeves are mounted on the spindle.

10. Machine for cutting off and successively unwinding sections of a web material on sleeves in order successively to produce a plurality of rolls, c h a r a c t e r i s e d in that it comprises at least one spindle (30) on which one or more sleeves (91) can be mounted in a sleeve mounting station, that turning devices (38, 38a, 38b) are provided for turning the spindle with the sleeve or sleeves mounted thereon to a web material attachment position, in which a first pressure roller (53) is provided to press the web material, as the web material is advanced between the first pressure roller and the sleeve/sleeves, against said sleeve/sleeves and against front and rear attachment unit portions (4,5), which are mounted in advance on the sleeve/sleeves and provided with adhesive surfaces such that the attachment unit portions will connect the web material to said sleeve or sleeves, and that said turning devices are provided to turn the spindle and the sleeve/sleeves further on and to synchronously advance the web material to a cutting station in which web cutting means (69,70) are provided to cut off the web material between said front and rear attachment unit portions and also to cut off any connections which may exist between the front and rear attachment unit portions in addition to the web material itself.

11. Machine according to claim 10, c h a r a c t e r i s e d in that a second pressure roller (65) is provided to press the trailing end of the cut off web material, which on its underside is provided with said front attachment unit portion, against the thence completed roll, such that the trailing end is fastened to the roll surface by means of said front attachment unit portion.

12. Machine according to claim 10 or 11, c h a r a c t e r i s e d in that the spindle (30) can be pulled out sideways beyond one side of the machine, such that a space is made available between the spindle and said side of the machine, in of from which space sleeves can be mounted on the spindle.

13. Machine according to claim 12, characterised in that said space has an extension in the lateral direction corresponding to at least the total width of the web material, preferably corresponding to at least the length of the spindle.

14. Attachment unit comprising a front portion (4) with upper (7) and lower (8) adhesive surfaces, and under the lower adhesive surface a covering sheet (12) with a lower adhesive surface (13), and a rear portion (5) with upper (9) and lower (10) adhesive surfaces, char acterised in that said adhesive surfaces have equally good adhesive capacities, but that the upper surface of the covering sheet (12) has such feature that the adherence of the covering sheet to the lower adhesive surface of the front portion is significantly impaired and/or that a release agent is provided between the lower adherence surface of the front portion and the covering sheet in order significantly to impair the adherence between the covering sheet and the lower adhesive surface of the front attachment unit portion.

15. Attachment unit according to claim 14, characterised in that it is covered by a protective sheet (3) of a release material contacting said upper adhesive surfaces (7, 9).

16. Attachment unit assembly, characterised in that a plurality of attachment units (1,1') are provided on a joint carrier (2) of release material, and that each attachment unit is covered by a protective sheet (3) of release material which can be torn away.

17. Assembly according to claim 16, characterised in that the attachment units are provided on said carrier (2) with the lower adhesive surface (13) of said covering sheet (12) under the front portion (4) of the attachment unit and the lower adhesive surface (10) of the rear portion (5) contacting the carrier (2), while the upper adhesive surfaces (7, 9) are covered by a protective sheet (3) of release material which can be torn away.