APPARATUS FOR WINDING A WEB

Abstract: The invention relates to a method and apparatus for on-machine winding of a web, in which a Pope reeling drum (10) is used, over which the web (W) to be wound passes. A reel spool (11) is driven by so-called centre drive. New reel spools (11′) are brought into connection with the reeling drum, after which the web (W) is conducted away from a fully wound roll to be wound onto a new reel spool. The method comprises, in combination, the following steps: an empty reel spool (11′) is brought into the grip of primary arms in such a way that bearing members (25) at both ends of the reel spool (11′) are being supported by guiding elements at each end of the reeling drum (10) in such a manner that the outer shell of the reel spool (11′) is not engaged with the reeling drum (10). The empty reel spool (11′), preaccelerated to winding speed, is brought into nip contact with the rotating reeling drum (10), the web (W) to be wounded running through the nip. Due to said nip contact, or only after it, the web breaks off or is severed by means of a double-sided adhesive tape wrapped round the reel spool (11′), whereby the web (W) begins to wind onto the empty reel spool (11) and the winding is continued by centre drive of the reel spool (11) and/or nip drive until the roll is fully wound, after which the above steps are repeated.

Description: The invention relates to an on-machine winder by means or which a web coming from a paper machine or other web making machine is wound on reel spools; the apparatus comprising a driven reel-up drum and primary arms in connection with it, which bring the empty reel spools onto the winder; and secondary arms, supporting the reel build-up, at least at its final stage. The US-A 3,094,294 discloses an apparatus for winding webs having a driving drum for the winding roll and a drive derived from the driving drum for a friction disk excentrically mounted relatively to the drum, by means of which the still empty reel core standing in readiness during roll changing is brought into correspondence with the speed of the web before the reel core is set on the web. Even in this apparatus a constant tension of the web when changing the reel core is difficult to achieve. FR-A-2 083 928 discloses a winding machine for webs having a device to severe the webs and has pivotable arms for transferring the reel core from a readiness position in an operational position. However, the core is accelerated on the web passing the outer circumference of the reeling drum. Therefore tension is applied to the paper web when accelerating the reel core on the reel drum. As is previously known, the so-called Pope-type reel-up is commonly used for reeling up a paper web coming from a paper machine or a printing machine, in which the roll is wound on a reel spool and the roll thus built up is pressed against a drive drum, or a so called Pope reeling drum, touching which the web partly runs and which is rotated at a peripheral speed matching the speed of the web. Prior to the completion of the roll, the new empty reel spool can be brought into contact with the drive drum in order to reach the matching peripheral speed. As soon as the paper roll has reached the desired diameter, it is moved free from the drive drum. Its rotation speed starts to slow down, which causes the web to form a slack sling between the new reel spool and the completed roll. This sling is then guided to wind round a new reel spool as by pressure air jets or other suitable means, whereby it naturally tears off the completed roll. As is previously known, the shaft of the paper roll. i.e., the reel spool, is usually supported and rotates on two rails. For this purpose both ends of the reel spool are provided with special bearing means, which also guide the path of the roll when, on completion, it is transferred along the rails for further treatment. In paper making this further treatment usually means slitting and rewinding the roll into smaller ones. For returning and changing the empty reel spools. e.g., a crane can be used. Especially when winding paper webs at higher speeds, a problematic phenomenon occurs, namely wrinkling in the inner layers of the roll, because of which the inner portion of the roll has to be rejected. The percentage of broke can be as high as 2-3%, which means considerable economical loss for the paper mill. The main reason for the wrinkling phenomenon is considered to be the variations in hardness (density) which occur in the inner portions of the paper roll. Variations in hardness are mostly caused by uncontrolled variations of the linear load as well as variations in the tension of the paper web to be wound. The most critical step in winding is when the growing roll is transferred from the primary arms onto the secondary arms. In practice, considerable variation occurs in the linear load at this point. This results in occasional wrinkling of the paper at the initial stages of winding as described above. The transfer of the roll from the primary arms to the secondary arms may also cause variation in density of the paper, which also causes the paper to wrinkle, or even to tear off. A previously known way to prevent the problems described above is to set the web at the highest possible tension but, as said before, a restrictive factor is the tendency of the web to break and the deterioration of the quality of the paper being produced, as then, e.g., the breaking strength and stretch at break decrease. Previously known means is also to raise the linear load as high as possible by using an excessively high load in the supporting arms, especially the secondary arms, by means of which the roll is pressed against the reeling drum. This method also has the drawback of deterioration of the quality of the paper being produced, as particularly the breaking strength and stretch at break decrease, as in the above method. Paper qualities which cannot allow being pressed against a Pope reeling drum can be treated by the apparatus according to this invention. One of these paper qualities is the A-copy (R) paper for self-copying, which has so-called micro capsules inside the paper. When the reel spool is brought into contact with the Pope reeling drum, it is usually done by means of arms, the reel spool pressing against the surface of the web. and thus causing broke to be produced for about half a minute. As the speeds of the paper webs are about 1000 m/min. the portion of broke produced is considerable and this causes substantial economical loss. It is the object of the present invention to provide an apparatus for winding a web, in which the transfer of the web from one reel spool to another can be done very speedily so that the time during which the reel spool touches the Pope reeling drum is considerably reduced, even to only a few seconds. The apparatus according to the invention for achieving the object described above is characterized in that the winder comprises guiding plates disposed adjacent both ends of the reeling drum, which plates have curved guiding peripheries, which mainly follow the periphery of the reeling drum, each guiding plate having a recess deviating from its general shape, directed towards the centre of the reeling drum, and disposed in such a way that when the bearing housings of the empty reel spool, guided by the primary arms, come to said recesses the outer periphery of the empty reel spool is brought into nip contact with the outer periphery of the reeling drum, due to which contact, or after it, the web is torn or cut off and is then transferred to wind from the full roll onto the empty reel spool, after which the primary arms immediately continue their journey and the effect of the recesses of the guiding plates ceases, whereby the reel spool is disengaged from the Pope reeling drum while continuously receiving the paper web. The motion of the primary arms is continued and the guiding plate disengages the reel spool from the nip contact once more while the reel spool is already receiving paper web. At this point the changing of the reel spools and conducting the web onto a new reel spool is completed and the full roll can now be further treated without haste caused by the exchange of the reel spools. As the web is very quickly conducted to wind onto a new reel spool and it is preferably cut off at the same moment as the reel spool comes into contact with it, the time for broke to be produced is very short, even only 3 to 5 seconds. The web can be cut in various ways, the most preferred of them in this embodiment being the so called adhesive tape cutting method, which is performed in such a way that the web adheres to and is torn off by a double-sided adhesive tape, which is wound or attached in some other way around the reel spool. The web can also be cut by the conventional balloon blowing method, in which air is blown on the nip between the reel spool and the Pope winder, which causes the web to rise upward and form a "balloon", break from the impact of air, and transfer to wind round a new reel spool. Previously known cutting methods are also edge blowing, or using a sharp-pointed object to make a hole in the web before blowing, and/or the use of a cord cutting device. This is important when applying an apparatus according to the invention on an old Pope winder. For carrying out the invention, a so called centre winder is generally used, which has drive means, e.g., direct current motors, one for the reel spool on the primary fork and one for the reel spool on the rails. When a paper reel has reached its full size, the secondary arms remove it and the primary arms transfer a new reel spool, located in the recesses of the guiding plates and already receiving paper web, further downwards onto the rails at the same time disengaging it from the Pope reeling drum to a distance of, e.g., 10 to 30 mm, depending on the paper quality being run. The winding is then continued on the rails, where the reel spool is driven by a drive motor of its own, the roll no longer touching the Pope reeling drum. The wrinkling of the paper, and consequently, the deterioration of the quality of the paper is thus prevented. In one embodiment of the invention, nip drive can also be used, in which the winding is performed with the reel spool in contact with the Pope reeling drum. If the guiding plate according to the invention is provided with a retracting device, a conventional drive means based on nip contact can be chosen, whereby the drive motor of the reel spool does not provide the driving torque. When a new reel spool is being brought into contact with the web on the surface of the Pope reeling drum, it is conducted into the recesses on the stationary guiding discs or plates attached to the sides of the Pope reeling drum. The reel spool is now supported on the primary arms through its bearing housings and, longitudinally, on the surface of the Pope reeling drum, but disengaged from the guiding plates. The guiding plates disposed at the sides of the Pope reeling drum may extend along the entire periphery of the drum, but only a certain portion of the periphery is in use, i.e. the portion where the reel spool is transferred to the winding position. The rest of the plate is constructed in accordance with fixing points and other functions, e.g., protecting functions. The winding apparatus according to the invention can be provided with an auxiliary device for moving the guiding plate or part of it out of the way. The winding is then performed by nip drive instead of centre drive, in other words, the winder functions in a prior art mode. Considerable savings can be made by using a solution according to the invention. The time for producing broke being only 3 to 5 seconds means that the broke can even be cut down to 10 % of the broke produced by known methods and apparatus. The invention is meant to be used in paper machinery. particularly in on-machine winding, but can also be used for other purposes. When the invention is used in a paper machine, it is especially suitable when making expensive paper qualities, whereby the savings are the most sizeable. The auxiliary device according to the invention, by means of which the guiding plates located at the sides of the Pope reeling drum can be moved out of the way and centre drive mode switched to nip drive mode when needed, can also be used to shift from centre drive to surface drive if desired. e.g., when starting to run less expensive paper qualities or when training operation personnel. The apparatus according to the invention is very reliable, as the transfer of the fully wound roll can be performed sufficiently slowly to avoid too high accelerations and thus extreme dynamic forces leading to wear of parts and malfunction of apparatus. Even though the invention is here described referring to on-machine winders in paper machines, it has to be pointed out that the method and apparatus according to the invention is suitable for using for other purposes, such as on-machine winding of plastic films or the like. In the following, the invention is described in detail referring to the figures of the drawings which illustrate certain embodiments of the invention whose details do not by any means strictly limit the invention. Fig.1 is a general view of the winder, where the invention is seen from the side of the machine. Fig. 2 shows a winder according to fig. 1 seen in cross section of the machine. Fig. 3 is a partial view of a Pope reeling drum and a guiding plate disposed at the outside of its ends, such a guiding plate being disposed at each end of the Pope reeling drum. Fig. 4 is a partial view of another embodiment of the invention, where the end part of the guiding plate can be moved away out of function so as to enable the adoption of the conventional surface drive principle. In the following the function of a winder in general, and a known embodiment of it are presented. The main part of the Pope winder, schematically shown in fig.1, is a reeling drum 10, along the periphery of which the paper web W travels for a little over a quarter of a revolution before passing onto the periphery of the paper roll building up on a reel spool 11. The reel spool 11 rotates supported by two supporting rails 12, secondary arms (not shown) pressing it against the reeling drum 10. The secondary arms also disengage the paper roll from the reeling drum 10, when the roll has reached the desired diameter. The finished paper rolls are transferred along the supporting rails 12 for further treatment and the empty reel spools are returned e.g. onto storing rails (not shown) disposed above the supporting rails 12. The transfer means for the reel spool 11 comprises guiding bars 14 extending upwards from the sides of the reeling drum 10 and pivotally mounted on bearings 17 at their lower ends and, moving up and down from each guiding bar, gap sledges, into whose gaps between the lower 15 and upper 16 jaws the bearing members of the reel spool 11 can be enclosed. The parts 14,15 and 16 form the so called primary arms. This invention relates to a winding technique where a so-called centre drive is preferably applied, wherein the reel spool 11 is driven through a coupling 13 attached to one or each of its ends. When replacing the reel spool 11 the lower jaws 15 are raised to the level of the ends of auxiliary rails (not shown) and the upper jaws 16 are raised to their upper position (not shown). Simultaneously the guiding bars 14 are rotated by drive means (not shown in fig.1) into such a position that no gap is left between the lower jaw 15 and the end of the auxiliary rail. The reel spool is allowed to roll from its upper position (not shown) into the gaps of the jaws 15,16, which are closed by lowering the upper jaws. The lower jaws 15 are lowered so as to bring the periphery of the reel spool close to (not into contact with) the periphery of the reeling drum 10, whereafter the guiding bars 14 are pivoted in the rotational direction of reeling drum 10. In previously known solutions, the guiding bars 14 being eccentrically mounted in bearings the distance between the reel spool 11 and the reeling drum 10 is further diminished until the reel spool 11 touches the paper web travelling on the reeling drum 10 and reaches a peripheral speed matching that of the web. The transfer of web W onto a new spool can now be performed in the previously known fashion and a successive reel spool can be lowered onto the supporting rails to replace the previous one. During the exchange, which is performed at the point where the reel spool presses against the web, broke is produced for about 30 seconds. The construction and function of the reeling drum described above is well-known in the prior art and this description is only meant to facilitate the understanding of the invention and its background. It should be pointed out that the present invention can be applied to winders of widely different types, also to off-machine apparatus, whose construction and function considerably differ from that of fig.1. In the following, an embodiment of the invention and its function is described in detail. In accordance with this invention, a guiding plate 20 is placed at both ends of a reeling drum 10, which may extend along the entire periphery of the reeling drum 10, or only a desired portion of the same. In any case, only the section a of the periphery of the drum 10 is essential from the point of view of the invention, as the invention is solely concerned about that section of the plate. The construction of the remaining portion of the plate depends on other factors, such as fixing points and, e.g., its protecting or other functions. There is a pair of guiding plates 20, spaced adjacent both ends of the drum respectively. They 20 have a curved guiding surface, which mainly follows the periphery of the reeling drum 10. The guiding plates 20 are provided with recesses 21, which smoothly deviate from the general shape of the plate 20 inwardly towards the centre of the reeling drum 10. A successive empty reel spool 11 is brought to the reeling drum 10 and placed above it in such a manner that bearing members 25 at both ends of the reel spool 11 are supported by guiding elements 20 located at both ends of the reeling drum 10, in such a way that the outer shell of the reel spool 11 is not in contact with the reeling drum 10. The empty reel spool 11′ can already be accelerated to winding speed at this point and then be transferred, guided by the guiding elements 20 and primary arms, to the recesses 21, with its bearing housings situated at their respective recesses. The outer periphery of the empty reel spool 11′ is similarly brought into nip engagement with the outer periphery of the reeling drum 10, through which nip the web to be wound passes. The web W may be severed and led to wind onto a new spool as an immediate consequence of the nip contact. In this preferred embodiment, adhesive tape 22 has been applied to the reel spool 11′, wrapped around the spool as shown in fig. 2, upon which the web W adheres and is immediately torn off due to the nip contact. The cutting off of the web may also be performed conventionally, in prior art manner, as by balloon or edge blowing or by cord cutting means after bringing the web into nip contact. After the cutting operation, in a first embodiment of the invention, the web W starts to wind onto the empty reel spool 11′, and the winding is continued by centre drive, whereby it is driven through a coupling at one end of the spool. In a second embodiment of the invention the winder is equipped with an auxiliary device 29, by which guiding elements 20 are removed out of the way after severing the web W, and the winding is continued by nip drive until the roll is wound to size, and the aforesaid steps are repeated. Thus the winder can be used in two alternative ways. In fig. 2 the winder according to the invention is shown in cross direction of the machine, where reeling drum 10, reel spool 11 and guiding plates 20 are seen. Double-sided adhesive tape 22 for cutting the web has been applied around reel spool 11 as shown in fig. 2. The winder according to the invention is provided with drive motors for the reeling drum 10 and the reel spool 11. Reference numeral 25 refers to the bearing housings of the reel spool 11 , which are located at the recesses 21. Reference numeral 31 refers to the couplings of the reeling drum. The walkway side and the drive side of the winder are referred to by respectively HP and KP. Fig. 3 is a partial view of the reeling drum of a winder, which shows one of the guiding plates 20 disposed on it, here extending along the entire periphery. The portion of the plate inside line 1 is not shown as its design varies according to the manner in which it is mounted, and, furthermore, this portion of the plate is not essential from the point of view of the invention. The plate may also be mounted in the way that the whole plate or part of it is pivoted enabling thus the recess to move along the periphery of the Pope reeling drum. Fig. 3 also shows the recess 21 in the plate for the bearing housings 25 of the reel spool 11. Fig. 4 shows an embodiment where the winder is provided with an auxiliary device. In this realization of the embodiment with an auxiliary device as shown in fig. 4, an auxiliary plate 26 is mounted on the guiding plate 20, by means of which the guiding plate 20 can be moved off position after nip contact. Plates 20,26 have now been connected with an actuator 29 through a rod 28. As stated before, the guiding plate 20 may also be of a different design from those shown in figs 3 and 4.

Claims: An on-machine winder used for winding the web (W) coming from a paper machine or the like web making machine onto reel spools (11), comprising a driven reeling drum (10) and primary arms which bring the empty reel spools (11') to the winder, and secondary arms supporting the roll, at least at its final stages of the build-up, characterized in that the winder comprises guiding plates (20) disposed adjacent both ends of the reeling drum (10), which plates have curved guiding peripheries, which mainly follow the periphery of the reeling drum (10), each guiding plate (20) having a recess (21) deviating from its general shape and directed towards the centre of the reeling drum (10) and disposed in such a way that when the bearing housings (25) of the empty reel spool (11'), guided by the primary arms, come to said recesses (21) the outer periphery of the empty reel spool (11') is brought into nip contact with the outer periphery of the reeling drum (10), due to which contact or after it the web (W) is torn or cut off and is then transferred to wind from the full roll onto the empty reel spool (11'), after which the primary arms immediately continue their journey and the effect of the recesses of the guiding plates ceases, whereby the reel spool is disengaged from the Pope reeling drum while continuously receiving the paper web. The winder according to claim 1, characterized in that said guiding plates (20) extend along the entire periphery of the reeling drum (10) or a portion of it. The winder according to claim 1 or 2, characterized in that the guiding plates (20) are stationarily fixed to the frame of the reeling drum or in that the guiding plate (20) or a portion of it is pivotally mounted to cause the recess (21) on the periphery of the plate (20) to move along the periphery of the Pope reeling drum (10). The winder according to any of claims 1 to 3, characterized in that it is provided with an auxiliary device (29), by means of which the guiding plate (20) or a portion of it may be moved into an off position in order to enable the use of said nip drive mode. The winder according to any of claims 1 to 4, characterized in that the cutting element is a cutting and gripping element attached to the reel spool (11), e.g., a double sided adhesive tape (22).

Inventors: SNYGG, KEIJO
Applicants: VALMET-AHLSTROM INC.
Application year: 1989
Main classification: B65H19
IPC codes: B65H18, B65H19