Method and device in web winding in connection with the set change of a slitter- winder

The invention relates to a method in the winding of a fibre web in connection with the set change of a slitter-winder, in which method the fibre web is wound in a carrier roll windup, in which partial webs cut by the slitter-winder are wound to web rolls carried by carrier rolls around cores, in which method the cores are fed to the slitter-winder as an array for the set change, in which method, for the time of the set change i.e. for removing completed rolls and starting new rolls, the winding is stopped, in which method the web is cut by means of a cutting device, the tails of the partial webs are fastened to the web rolls, completed web rolls are removed by means of a roll pusher, new cores are transferred to the support of the carrier rolls. The invention relates to a method according to the preamble of claim 1.

The invention relates also to a device for implementing the method according to the preamble of claim 16.

By means of slitter- winders, a full-width web is cut in the longitudinal direction to partial webs on the cutting section and the partial webs are wound to customer rolls on the winding-up section. In windups, the partial webs are wound around cores to fibre web rolls and the longitudinal successive cores are locked in place to a core array by means of a core-locking device located at both ends. In the slitter-winder, many times carrier roll windups are used as the windup, in which windups, the partial webs are wound carried by two carrier rolls to partial web rolls via a nip between a second carrier roll and a fibre-web roll being formed. Also a belt arrangement i.e. a so-called set of belt rolls located around two leading rolls can be used as the carrier roll.

Also, slitter-winders are known from prior art in which carrier roll windups are used for winding partial rolls after the slitting of a paper or board web. The present invention relates to windups of carrier roll type in which the slit partial webs are wound around winding tubes, e.g. cores, supported by two rolls or by one roll and one set of rolls. In the following description and claims, the term carrier roll is used for simplicity when referring to a support roll/set of rolls of a windup of carrier roll type i.e. including both the meanings of a carrier roll and a set of belt rolls. Additionally in this description, the term core means also other types of winding tubes used and suitable for use in windups of carrier roll type. Furthermore in this description, partial webs being wound on the windup and web rolls being formed are referred to, according to context, either in singular or plural but meaning all partial webs and web rolls handled in the windup. From prior art are also known carrier roll windups of variable geometric in which one or both of the carrier rolls carrying the web roll are transferable. In such variable-geometric slitter-winders, the central horizontal location of the roll being formed depends on the position of the carrier rolls in respect to each other and the diameter of the roll.

In the slitter-winder in winding a fibre web, a set change means a stage in which when manufacturing rolls always before starting a new winding the winding has to be stopped, the web to be cut by the windup and the set i.e. completely wound rolls to be removed and after setting new cores the winding of the new set i.e. partial web rolls to be completed next to start again. Nowadays, the set change time in web winding is in practice, when using machine arrangements, around 30- 70 seconds from stopping the winding to its re-starting.

A problem in connection with windups known from prior art relates to fastening the tail of partial web rolls being wound i.e. each fibre-web roll being completed for the set change. To the fastening of the tail of a fibre-web roll being completed i.e. the tail end of the web going to the roll is used a method in which glue stripes are applied on the web before the winding-up nip, and the glue stripes are run inside the roll through the winding nip before stopping the windup. The fibre-web

roll is in contact with both the rear carrier roll and the front carrier roll, whereby the glue is pressed fast in the winding nip between the rear carrier roll and the fibre-web roll being formed. This causes a problem in a stage in which the completed fibre-web rolls are pushed out of the windup, because the glued web can open from the roll. An opening web causes with certain web grades, especially heavy grades, such as board webs, splitting on the area of the glue stripe i.e. the glue does not give up any more but the surface layer of the web is detached with the glue instead of the glue stripe opening on the glue area. The split glue stripe will not adhere any more, whereby the tail remains detached from the roll in the completed roll. The detachment of the web end from the roll can cause tearing of the web and problems in the measuring and the transport and further processing of the fibre-web roll. On the other hand, when winding thin fibre webs, a problem can be that the glue can be pressed through several web layers because of the pressing effect of the nip.

The problem related to the gluing of the tail will now be described in more detail with reference to the Figs. IA and IB of the accompanying drawing. A fibre-web roll 10' being formed comprises an area T ₂ which is a glue stripe area gone through a nip formed by a rear carrier roll 11' and the fibre- web roll 10'. Reference T ₁ refers to a glue stripe being open. Reference number 15' refers to a cutting blade which is placed according to the next core size. When according to what is shown in Fig. IB the completed fibre- web roll 10' is transferred by a pusher 17' towards a front carrier roll, here a set of belt rolls, which is formed of two rolls 12', 13' and a belt 14' for the pushing out, the length T ₁ is as in the version shown in Fig. IA, and reference T ₃ refers to the portion of the glue stripe V ₂ which opens during pushing out and on which area possible splitting can occur. Reference T ₄ refers to a glue stripe which does not open. Thus, only a small area T ₁ tries to keep the tail fastened to the roll 10' after cutting and pushing out, which has many times proven inadequate, and the tail of the web can have been left to flap and the roll has later started to unwind.

Also different methods are known from prior art for cutting the web and for web cutting devices to be used in connection with windups of carrier roll type, of which one is presented in Finnish patent specification 101876. In this known arrangement, a separate counter blade is required for obtaining an adequate cutting angle for the cutting blade rising from between the rolls. Furthermore in this known arrangement, a separate remover of small rolls is required for removing small rolls from the windup. A windup of this type is shown in Fig. 2 in which reference number 17' refers to the roll pusher and reference numbers 15', 16' refer to the cutting device of the web which comprises the cutting blade 15' and the counter blade 16'. A lowering device of a completed roll 10' is designated with reference number 19' and a tail gluing device with reference number 29'. The series of figures 3A-3D, for their part, show a counter-bladed web cutting sequence known from prior art, and figures 4A-4C show a cutting sequence known from prior art implemented without a counter blade. These known cutting sequences are described in more detail in a special part of this description. Known arrangements have many times required a so-called final rotation during which the completed web roll is rotated once more around its axle for fastening glued tails in a nip between the roll 10' and the roll pusher 17'. For this, up to 10 seconds have passed, which is a lot as such when the set change takes only the total of 30-70 seconds. In addition, in arrangements known from prior art without a counter blade, it is necessary for implementing cutting to make a small so-called cutting motion by the cutting blade, whereby the actual location of the cutting point remains ambiguous.

A problem existing in connection with prior-art carrier roll windup relates to the measuring of the length of cores. As known from prior art, the length of cores is measured so that during the feeding of a core array the location of the end of the core array is measured by a sensor in relation to the location of the other end, whereby the length of the core array is discovered. A disadvantage of this practice is that if there are several cores in the array to be fed, it is not possible to measure the length of individual cores because the joint between the cores cannot be

distinguished reliably enough. If the cores were fed and thus also measured individually, too much time would pass especially when winding thick fibre-web types, because the time to be spent is dependent on the completing time of the rolls which is not usually enough for separate feeding and measuring of the cores and thus the cores must be fed as an array. On the other hand, there can be so many partial rolls being wound simultaneously that there is no time for the individual feeding and measuring of the required cores, even though the completing time of the rolls might enable separate feed and measurement. By means of an arrangement known from prior art as such, one is able to have information on the length of the core array, but no information on the lengths of individual cores nor on the relative order of cores of different lengths is obtained.

In windups of carrier roll type known from prior art, the core array is gripped with a suction cup array for transferring them to a winding position for starting a new set. Arrangements known from prior art use suction cups in one array from which the cores can be easily detached because of a force perpendicular in relation to the central axle of the suction cup affecting the core. The force can be caused by gravity or acceleration. Furthermore, the position of the cores during transfer is inaccurate when using only one suction cup array.

The object of the invention is to provide a method and a device in web winding in connection with the set change of a slitter-winder in which the above-described problems and disadvantages have been eliminated or at least minimised.

An additional, non-essential object of the invention is to create a method and a device by using which the gluing of the end of the web to the fibre-web roll being completed takes place so that no splitting is able to occur with thick fibre web types, nor the end of the web remains hanging loose in the completed roll and, on the other hand, when winding thin grades, the glue does not penetrate through several layers.

A non-essential further object of the invention is to provide an arrangement in which, for cutting the web, there is no need for a separate counter blade and in which, on the other hand, the location of the cutting blade is stationary in the time of cutting, whereby the cutting point is accurate.

Furthermore, a non-essential additional object of the invention is to provide an arrangement in which no separate remover of small rolls is required.

An non-essential further object of the invention is to provide a measuring arrangement for measuring a core length by which the length of each core in the core array and the order of the cores in relation to each other are discovered.

A non-essential additional object of the invention is to provide an arrangement in which the transfer of the core array is reliable and the position of the cores is accurate.

To achieve the above-mentioned objects and those which come out later, a method according to the invention is mainly characterised by what is presented in the characterising part of claim 1.

Again, a device according to the invention is mainly characterised by what is presented in the characterising part of claim 16.

According to an embodiment of the invention, a completing fibre-web roll is pushed off the rear carrier roll during the deceleration of the roll before gluing or during gluing the end of the web so that the cutting blade of the web is able to transfer up to the cutting position without the web breaking. In this embodiment of the invention, a glue stripe or at least its tail part does not go to the completing web roll until the roll has been lifted off the rear carrier roll. Thus, an advantage is achieved that a greater part of the glue stripe remains bare to wait for the final compression in a nip between the roll pusher and the roll and, on the other hand,

that the glue stripe opening during the pushing out has not gone through a nip between the rear carrier roll and the web roll being formed, whereby the glue has not been pressed, nor splitting occurs so easily than in arrangements known from prior art, nor there is a risk of the glue being pressed through several layers with thin grades. In this embodiment of the invention, the glue is pressed before final compression only with web tightness and it has not passed through the winding nip. In this embodiment of the invention, a novelty is that the completing fibre- web roll is transferred for a small travel when carrier rolls still rotate. After this, the web roll can be stopped, if required, and started again for rotating or the web roll can rotate carried by the front carrier roll and the roll pusher for the whole time. Thus is obtained a completed fibre-web roll glued to the finish. A further advantage in this is also that because the glue has not been under compression in the nip, the glue adheres during the actual gluing better when being fresh, because no compression and thus spreading of the glue has occurred in the earlier stages.

According to an embodiment of the invention, the roll pusher of the completed roll is designed and arranged to move so that it can form an adequate cutting angle for the web against the stationary cutting blade. The roll pusher is of such a shape that it fits between the web roll and the roll without the centre of gravity of the rolls transferring over the top of the foremost carrier roll in the vicinity of the first carrier roll before the web is cut, most suitably the roll pusher is thin. The roll pusher is arranged to move in the beginning of the pushing motion before the web cuts. The roll pusher is advantageously provided with a guide part via which also a small roll can be pushed out of the winding assembly without a remover device of small rolls being moved by a separate actuator. This embodiment of the invention enables a cutting blade stationary during cutting without a counter blade, because the web folds at an adequately sharp angle against the cutting blade, the guide part ensuring the travel of the web, and further tightens against the blade and cuts, whereby the cutting point is accurate and no complex arrangements are required for implementing the counter blade. At least partly, the roll pusher extends on the other side of a line passing via the centres of the fibre-

web roll being formed and the rear carrier roll, whereby the pushing motion of the roll provided via it brings the roll so far that the tail of the gluing becomes pressed against the roll in a nip between the pusher and the roll controllably against an area sloping upwards of the lowering device, which in part also enables that the roll will not escape but remains in control.

According to an embodiment of the invention when feeding a core array to a windup, the core being measured in the array is pulled more quickly than the other array, whereby there remains a gap between the core being measured and the remaining array, by means of which gap it is possible to measure the length of the core as a direct measurement by measuring the distance between the first end of the core and the second end of the core or as an indirect measurement as a difference of the earlier measurement and the length of the remaining core array. In this way, information on the length of an individual core is obtained quickly enough when the measurement is performed before feeding the cores to the windup and when pulling always one i.e. the core to be measured aside. The measurement can be done either from the end of the core being measured as a direct measurement or from the end of the first core in the remaining core array as an indirect difference measurement. After the measurement, the cores are pushed to the machine, whereby the gaps between them close up and the core array is lockable in place between the core locks. On the other hand, it is possible to implement the measurement also so that the core being measured is deflected momentarily apart from the feed direction compared to the other core array and the measurement is performed. After the measurement, the core is returned to the feed direction and the cores are pushed to the machine, whereby the gaps between them close up and the core array is lockable in place between the core locks. Thus is obtained information on the length of each core in the core array and on the order of cores of different lengths in relation to each other. Measuring means can comprise an absolute sensor which measures the location of the core array, and/or a linear sensor or a photo cell or a measuring means based on laser measuring by means of which the location of the core separated from the array is measured. For

pulling the core to be transferred apart from the core array is used an actuator which can be e.g. a drive wheel or a separate belt having a different speed than the belt of the core array or a pusher by which the core being measured is deflected from the array, or the core being measured can be deflected from the array by means of gravity.

In a windup according to an embodiment of the invention, for transferring the core array from a channel to a mouth between the carrier rolls are used suction cups which are placed to at least two arrays, or at least two suction zones. The suction cup arrays or suction zones are arranged parallel, at an angle in relation to each other, to a distance from each other extending in the longitudinal direction of the core array. Thus, the grip to the cores is solid and, further according to an advantageous additional characteristic of the invention, the angle and distance between the arrays can be adjusted according to the space between the carrier rolls and the core size so that an adequate force is obtained for gripping the cores and further the location of the cores is known accurately. According to this embodiment of the invention, the cores are gripped with two or more arrays of suction cups or with two or more suction zones, and the position of the suction cup arrays/suction zones in relation to each other can be fixed or advantageously settable according to the diameter of the cores and the space between the carrier rolls. The suction cup arrays are most advantageously fastened/the suction zones are arranged to beams which, for their part, are fastened to the core feeder which brings the cores to the mouth between the rolls after the previous completed roll has exited. The mutual position of the suction cup arrays/suction zones is changed with a mechanism, e.g. a pivot mechanism, or guides moved by an actuator, e.g. a cylinder or a motion screw, which changes the distance between the beams in which the suction cups are fastened and possibly the angle between the beams. The mutual position of the suction cup arrays is set suitable according to the core size and the space between the carrier rolls.

The present invention and its different embodiments apply for use extremely advantageously when winding thick fibre-web types, such as boards, more especially coated boards, because splitting is especially a problem of coated board grades and, on the other hand, because when winding thick grades the rolls are completed quickly, whereby there is no time for measuring individual cores. Also the cores of thick grades are many times heavy and thus require a lot of lifting power, which is achieved with the advantageous embodiment of the invention. The invention and its different embodiment are also usable in winding thin web grades.

The invention will now be described in more detail with reference to the figures of the accompanying drawing, to the details of which the invention is, however, by no means intended to be narrowly confined.

Figs. 1A-1B schematically show an arrangement known from prior art in gluing the tail leader of a web.

Fig. 2 schematically shows an arrangement according to prior art in which the cutting of a web is implemented by means of a cutting blade and a counter blade.

Figs. 3A-3D schematically show a sequence chart of an arrangement known from prior art when using counter-bladed web cutting.

Figs. 4A-4C schematically show an arrangement according to prior art in which the cutting of a web is implemented by means of a cutting blade making a cutting motion.

Figs. 5A-5C schematically show an embodiment in connection with the invention to be used as a measuring arrangement in measuring cores.

Figs. 6A-6B schematically show an embodiment for an arrangement to be implemented in connection with the gluing of the tail leader of a completing roll.

Figs. 7A-7D schematically show an arrangement according to an embodiment of the invention for pushing the completing web roll out.

Figs. 8A-8C schematically show an arrangement according to an embodiment of the invention for removing a small roll from the windup.

Figs. 9A-9B schematically show an arrangement according to the invention for transferring a core array.

The following figures schematically show arrangements known from prior art and different embodiments of the invention. In the figures, parts corresponding each other have been referred to with the same references, however so that in the arrangement according to prior art the reference numbers are marked with an apostrophe.

Fig. IA schematically shows a winding stage in an arrangement known from prior art in which stage a fibre-web roll 10' is about to be completed and glue has been applied to it in order to make the surface layer to adhere to the completed fibre- web roll 10'. A rear carrier roll is referred to with reference number 11' and a front carrier roll is formed of a set of belt rolls which comprises two rolls 12' and 13' and a belt 14' arranged around them which belt forms an endless belt loop. A cutting blade has been referred to with reference number 15' and its counter blade with reference number 16'. According to Fig. IA, after applying the glue, a glue area T ₂ has been formed on the surface of the fibre- web roll 10', which is a glue area gone trough the nip formed by the rear carrier roll 11 ' and the fibre- web roll 10' being formed which is tightly glued as the mass of the fibre-web roll 10' affects in the nip as a pressing force. The glue area, which when transferring the fibre- web roll 10' towards the pushing out stage opens up, is designated in the

figure with reference T ₁ . When the fibre-web roll 10' in a situation according to Fig. IB has been pushed to pushing out for cutting, the glue area T ₁ is open, as in the above-mentioned stage, and from the fibre-web roll 10' when the web tightens the open glue area T ₃ opens up and can split the glue being extremely tightly fast in the fibre-web roll 10', and the glue area remaining fast in the fibre-web roll 10' is referred to with reference number T ₄ . When the fibre-web roll 10' has been pushed out by a roll pusher, only the glue area T ₁ trying to keep the tail of the web fast to the roll 10' after cutting and pushing out has remained on the surface layer of the web, because it is possible that the glue area T ₃ has opened and split.

Fig. 2 schematically shows an arrangement known from prior art in which counter-bladed cutting is used i.e. in which in addition to a cutting blade 15' into connection with the windup is arranged a counter blade 16' by means of the interaction of which the web is cut. A tail gluing device of the web is designated with reference number 29 '.

In a situation according to Fig. 3 A, the fibre-web rolls 10' have gained a desired size of their diameter i.e. the roll 10' is a full roll, and the carrier roll windup has been stopped. Next, according to Fig. 3B, the first cutting member 15' is lifted from a gap between the carrier rolls 11' and 12', 13', 14' upwards to the point that the cutting point is accurate according to the diameter of new winding cores. Simultaneously, the tip of the roll pusher 17', which is advantageously a roll, is rotated upwards carried by pivots. After this, the roll pusher 17' is started to be rotated carried by the pivots, whereby the tip of the roll pusher 17' pushes the roll 10' apart from the rear carrier roll 11' so much that a second cutting member 16' fits to move from up to down from a gap opened by the full roll. Rotating the tip of the roll pusher 17' upwards supported by the pivots provides an adequate space for the cutting member 16' to move from below it. Fig. 3 C shows a situation in which the completed roll 10' is pushed by the roll pusher 17' to a lowering device 19'. Fig. 3D shows a situation in which a new winding core i.e. core 20' is set to the support of the carrier rolls 11' and 12', 13', 14' to a gap between them, and a

new winding is thus ready to start from the carrier roll windups in a known way as such.

Figs. 4A-4C schematically show an arrangement known from prior art in which no counter blade is used for cutting. In a situation shown in Fig. 4A, the fibre-web roll 10' is completing and the fibre web W is wound supported by the rear carrier roll 11' and the set of belt rolls 12', 13', 14' to the fibre-web roll 10'. In a situation shown in Fig. 4B, the roll pusher 17' is transferred to push the completed fibre-web roll 10' towards the lowering device 19' and the cutting blade 15' rises to the cutting position and performs a separate cutting motion for cutting the web. In a situation shown in Fig. 4C, the completed fibre-web roll 10' is transferred to the lowering device 19' and a new core 20' has been transferred to the support of the rear carrier roll 11' and the set of belt rolls 12', 13', 14' and the cutting blade 15' has been lowered to the stand-by position.

Figs. 5A-5C schematically show measuring the length of a core array 20 according to an embodiment of the invention. The core array comprises several cores 2O ₁ ... 2O ₅ of different lengths which are pushed as a core array 20 by a conveyor forming of rolls 21, 23 and a belt 22 rotating around them with speed V ₁ towards the windup. Into connection with the conveyor has been arranged an absolute sensor 24 by which the location of the core array is measured, and a second sensor 26 which is most suitably e.g. a linear sensor by means of which the length of a core separated from the array is measured. In a situation of Fig. 5A, the core array 20 is about to be transferred towards the windup and in the measuring stage a location data 1 i.e. the position of the first end of the core 2O ₁ being measured in the core array 20 is obtained from the measurement of the sensor 26. In Fig. 5B, the core 2O ₁ being measured in the core array 20 has been transferred at least partly apart from the other array by means of e.g. a drive wheel 27 of different speed V ₂ or a belt or by deflecting it in the cross direction by e.g. a pusher and in the vertical direction by means of e.g. gravity. According to the invention, the measurement can be performed as a direct measurement by

measuring the first end, Fig. 5A, and the second end of the core by the sensor 26, Fig. 5B, or as an indirect measurement by means of a gap F or a deflection point remaining between the core 2O ₁ being measured and the remaining core array 20 to measure the length of the first core 2O ₁ as a difference from the previous measurement (location data 1), Fig. 5A, and of the length of the remaining core array 20 (location data 2), Fig. 5C. According to what is shown in Fig. 5C, the location data 2 is obtained when the sensor 26 measures the first end of the following core 2O ₂ i.e. the end of the remaining core array 20, whereby the length L of the core 2O ₁ being measured is location data 1 - location data 2. The length of the other cores 2O ₂ ...2O ₅ in the core array 20 is measured correspondingly. In the core array shown in the figure, there are five cores, but naturally the number of the cores varies according to the situation and the windup, conventionally between 2- 8.

Figs. 6A-6B schematically show an arrangement according to an embodiment of the invention in which a completing fibre-web roll 10 is pushed off the rear carrier roll 11 by the roll pusher 17 during the deceleration of the roll 10 and before applying and during applying the glue so much that the cutting blade 15 is able to rise up without the web W breaking. When the applying of the glue is performed according to the invention so that the glue stripe or at least its tail part does not go to the completing roll until the completing roll is off the rear carrier roll 11, a greater part of the glue stripe remains bare to wait for the final compression in a nip between the roll pusher 17 and the fibre-web roll 10. In a situation according to Fig. 6 A, the fibre- web rolls 10 are pushed by the roll pusher 17 apart from the rear carrier roll 11 in the deceleration stage before stopping the windup and the glue stripes are run to the fibre-web roll 10 and the machine is stopped so that the glue stripe remains above the cutting point. The length of the open glue area I ₁ is around 200-300 mm, and the portion of the glue area pressed fast with web tightness is I ₄ , and a glue area I ₅ has gone trough the nip of the roll pusher 17 and/or the rear carrier roll 11. A situation is evident from Fig. 6B in which a completed fibre- web roll 10 is being transferred by the roll pusher 17 towards the

lowering device, whereby a glue area I ₆ opens again from the roll 10 which area is thus partly the glue area I ₄ of the above-mentioned figure, but compared to what is known from prior art, this glue has been pressed tightly fast as it has not passed in a nip between the rear carrier roll 11 and the completing roll 10, whereby the splitting risk caused by it is considerably lower than in arrangements known from prior art. A glue area I ₇ is, for its part, the glue area I ₅ of the previous figure and the portion of the glue area I ₄ which remains fast in the roll. The glue areas I ₆ and I ₁ are glued in a nip between the roll pusher 17 of the roll 10 and the roll 10 when pushing the roll 10 further towards the lowering device.

Figs. 7A-7D schematically show an embodiment of the invention for a new roll pusher 17 which is arranged so that a tail glued to the roll 10 is wound fast to the surface of the roll by a pushing motion of the roll pusher 17 controllably so that the roll cannot escape from the contact with the roll pusher, whereby there is necessarily no need for rotating the front carrier roll. As is evident from the figures, the roll pusher 17 is designed and arranged to move so that it can form an adequate cutting angle for the web against the cutting blade without the centre of gravity of the rolls to transfer over the top of the foremost carrier roll 18. The roll pusher 17 is of such a shape that it fits between the web roll and the roll without the centre of gravity of the rolls transferring over the top of the foremost carrier roll in the vicinity of the first carrier roll before the web is cut, most suitably the roll pusher is thin. The roll pusher 17 is provided with a guide part 17A via which also a small roll can be pushed out of the winding assembly without a remover device of small rolls being moved by a separate actuator. In a situation shown in Fig. 7 A, the fibre- web roll 10 is being completed and, in Fig. 7B, the cutting blade 15 has been lifted to the cutting position. In a situation shown in Fig. 7C, the completed fibre- web roll 10 is pushed by the roll pusher 17 towards the top of the front carrier roll 18, whereby the cutting blade 15 cuts the web W, whereby the guide part 17A of the roll pusher ensures the accurate path of the web. In a stage shown in Fig. 7D, the roll pusher 17 pushes the completed roll to the lowering device.

Figs. 8 A-8C schematically show an advantageous embodiment of the invention in which the roll pusher 17 according to an advantageous embodiment of the invention is used for removing a small roll 10. The roll pusher 17 corresponds with its substantial characteristics the one described in connection with Figs. 7A- 7D. In a situation shown in Fig. 8A, the guide part 17A of the roll pusher 17 is brought to contact with the small roll 10 being removed which roll 10 is in the support of the carrier rolls 11, 18 in a gap between them. According to Fig. 8B, by means of the guide part 17A of the roll pusher 17 the small roll 10 is pushed towards the lowering device 19 and, in Fig. 8C, the small roll 10 has been transferred to the lowering device 19 by the roll pusher 17, after which the roll pusher 17 is returned to the stand-by position for next required removal of either a small roll or a large roll, and the small roll 10 exits by means of the lowering device 19.

Figs. 9A-9B schematically show an embodiment of the invention in which for transferring the core array 20 from a channel to a mouth between the carrier rolls into connection with the windup has been arranged at least two suction cup arrays 31, 32 which grip the core array 20 and move the cores in the core array 20 safely and reliably to the support of the carrier rolls 11 and 18. The suction cup arrays are fastened/the suction zones are arranged to beams which, for their part, are fastened to the core feeder which brings the cores to the mouth between the rolls after the previous completed roll has exited. Fig. 9A shows the grip to a small core and Fig. 9B to a large core. The angle and the position between the suction cup banks 31, 32 is adjustable according to the space between the earner rolls and the used core size so that a solid grip is obtained of the core array 20. Instead of a suction cup bank, two unitary suction zone 31, 32 are applicable.

The invention was described above only referring to some of its advantageous embodiments, to the details of which the invention is, however, by no means intended to be narrowly confined.