Method and apparatus for winding a web

Abstract: The invention relates to a method for on-machine winding of a web (W), in which method a Pope-type reel drum (10) or corresponding reeling means is used and over which the web (W) to be wound is conducted. In the method, new reel spools (11) are brought into contact with the reel drum (10), after which the web (W) is conducted from the fully wound roll to be wound onto the new reel spool (11). In the method primary forks (14), when in their upper position, pick up an empty reel spool (11A,11B) without any auxiliary equipment. Guided by the primary forks (14) and supported on support plates (17) attached on the primary forks (14), the empty, preaccelerated reel spool (11B,11C), is brought into nip contact with the rotating reel drum (10) and through the nip of which the web (W) to be wound runs, and is wound round the reel spool (11) at the nip contact. The support plates (17) remain in such a position while the primary forks (14) are being lowered that the contact pressure between the reel spool (11C-11E) and the reel drum (10) remains substantially constant while the primary forks (14) are moving from the upper position to the lower (see vector diagrams, Fig. 2). When the primary forks (14) are in the lower position, the support plates (17) turn into such a position that they may pass the reel spool (11), which is already positioned on the reeler tracks (12), when the primary forks (14) are moving back into their upper position, and the above steps are repeated when it is time to exchange reel spools (11) again and the support plates (17) are ready to receive one. The invention also relates to the apparatus used in the method.

Description: The invention relates to a method for on-machine winding of a web, in which method a Pope reel drum or corresponding reel component is used over which the web to be wound is conducted and in which method new reel spools are brought into rolling abuttment with a reel drum, after which the web is conducted from the preceding, fully wound reel and wound onto a new reel spool. The invention also relates to an apparatus for on-machine winding by which a web coming from a paper machine or a corresponding machine for web-making is wound onto reel spools and which apparatus comprises a reel drum provided with drive means and primary forks or arms associated therewith, which forks bring the empty reel spools onto the surface of the reel drum, and supporting tracks on which the machine roll builds up while being wound. According to prior art it is common to use a so called Pope reeler to wind, for example, the paper web coming from a paper machine, whereby the roll is wound on a so-called reel spool and the roll building-up is pressed against the driving roll, a so-called Pope reel drum, and partly over which the web runs and which drum is rotated at a peripheral speed matching the speed of the web. In prior art machines the reel spool is brought onto the primary forks or arms from the storage frame by means of separate forks or arms. An arrangement like this is very tall, while the lifting heights of the cranes, especially in older machine halls, are often not adequate for this. For reasons referred to above, high costs are caused. An apparatus of this type is disclosed in the Finnish patent No 860834. In prior art machines, the load at the nip of the reel spool and the reel drum is achieved by means of a roll and a loading device. When in the upper position, the load is effected by the weight of the reel spool itself as well as by the load from the loading device, but when directing the spool supported on the primary arms towards the lower position, the force component from the weight of the spool itself diminishes and is at zero when the reel reaches the lower position, at which point only the load force applied by the loading device is effective. For the above reasons, a special load relief cylinder is needed to control the pressure force caused by the weight of the reel spool. The pressure of the cylinder has to be steplessly adjusted during the lowering of the primary forks. The present technology cannot provide a cheap stepless way of transmission functioning without a synchronizing shaft which would, at the same time, provide a reliable even run, as in this solution the load relief cylinders also expand during the movement of the primary forks. Such an apparatus is disclosed in Valmet's U.S. Patent No 4 634 068. It is an object of the present invention to provide a method and apparatus for winding a web by means of which an even distribution of load across the width of the paper web is achieved between the reel spool just loaded and during initial winding until supported by secondary arms and the reel drum during the exchange of reel spools. It is a further object of the present invention to provide a method and apparatus for achieving a speedy exchange of the reel spools. It is a still further object of the invention to provide a simple and reliable construction where the need for auxiliary equipment is minimized. According to the present invention there is provided a method for on-machine winding of a web, in which method a Pope reel drum or corresponding reeling means is used, over which the web (W) to be wound is conducted and in which method new, empty reel spools are brought into contact with the reel drum, after which the web (W) is conducted from a previous, fully wound reel to be wound onto a new reel spool, and wherein the contact pressure between the reel spool and the reel drum is maintained substantially constant characterized in that the method comprises, in combination, the following steps: a. picking-up an empty reel spool by means of primary forks when in the upper position and without any auxiliary equipment whereby said empty reel spool rolls onto said primary forks; b. with the empty preaccelerated reel spool being guided by the primary forks and supported on support plates attached to the primary forks, bringing said reel spool into nip contact with the rotating reel drum, through which nip the web (W) to be wound runs and is wound around the reel spool at this nip contact, with the support plates being selected of such shape and being retained in such a position during the lowering of the primary forks to ensure substantially constant contact pressure is maintained while the primary forks move from their upper position to their lower position; c. wherein the contour surface of the support plate is selected or designed as to have a support angle such that the support plate vector which is a component of the vertical vector (B) representing the force of gravity on the reel spool is at right angles to the tangent (D) through the point of contact between the supporting counter surface of the supporting plate and the reel spool, and such that the drum contact force vector (A) which is the other component of the vertical vector (B) remains constant or substantially constant during the entire lowering movement of the primary forks; and d. with the primary forks being in their lower position, turning the support plates into such a position that they pass the reel spool, already supported on the reel tracks, as the primary forks move back to their upper position, and, as required, repeating the mentioned steps when it is time to change reel spool again and the support plates are ready for receiving one. Also according to the present invention there is provided an apparatus for on-machine winding of a web (W) coming from a paper machine or corresponding web-(W) making machine onto reel spools, which apparatus comprises a driven reel drum and primary forks associated therewith and which bring empty reel spools from a storage frame for storing the empty reel spools, ready to be picked up by the primary forks, without any auxiliary equipment, to the reel drum and tracks, supported on which the web roll, at least in the final stage of the winding, builds up, and wherein the contact pressure between the reel drum and the reel spool remains substantially constant regardless of the height position of the reel spool, characterized in that - support plates are attached to the primary forks, and an empty reel spool is supportable thereon and can be brought into nip contact with the rotating reel drum by lowering the primary forks, said support plates being provided with a counter surface whose shape and position is such that when lowering the reel spool, said substantially constant contact pressure is maintained; said substantially constant contact pressure being maintained by the contour surface of the support plate having a support angle such that the support plate vector which is a component of the vertical vector (B) representing the force of gravity on the reel spool is at right angles to the tangent (D) through the point of contact between the supporting counter surface of the supporting plate and the reel spool, and such that the drum contact force vector (A) which is the other component of the vertical vector (B) remains constant or substantially constant during the entire lowering movement of the primary forks. The exchangeable support plates can vary in design for achieving the suitable contact pressure for each paper grade. The support plates can also be fixed with regard to the primary forks. In that case the primary fork can only be elevated when the paper roll is built up to adequate size. By provision of a turning mechanism for the support plates, a swift turn of the primary forks into the upper position is made possible, which is useful in exeptional situations, for example, if there is a failure with starting a new paper roll and an exchange of reel spools must immediately be carried out. The turning of support plates that are pivotally mounted to the primary forks is accomplished, for example, either by the force of gravity, or a spring, or a hydraulic or pneumatic cylinder controlled by, e.g., a limit switch depending on the position of the primary forks. The relief of load necessary for delicate paper grades is accomplished by means of hydraulic cylinders located at the upper portion of the primary arms directly underneath the bearing housings of the reel spool. The relief of load diminishes the contact pressure, but it still remains substantially constant. In the apparatus according to the invention, a special means for lifting the reel spool from the storage frame onto the primary arms is not needed, as the shape of the primary arms and the pivoting point are such that, while being elevated, the primary arms pick up the empty reel spool from the storage frame. Furthermore, the surface of the beam of the storage frame is inclined towards the primary arms, due to which fact the new reel spool can replace the previous reel spool taken to the reel drum or "reeler". No auxiliary equipment is needed for achieving a contact force between the spool and the reel drum, as the contact force is accomplished by means of the weight of the spool itself and a suitable angle chosen for the counter surfaces of the support plates. The invention is now described further, by way of example, with reference to an embodiment shown in the figures of the attached drawings, to the details of which the invention is by no means strictly limited. Fig. 1 is a general side view of a reeler constructed in accordance with the invention. Fig. 2 is a fragmentary view of the reeler of Fig.1 schematically illustrating the control system for the contact force between the reel spool and the reel drum according to the invention. The construction and function of the reeler according to the invention is described in the following. The principal part of the Pope-type reeler schematically shown in the figures includes a reel drum 10, along the periphery of which the paper web runs for a little over a quarter of a revolution before it is transferred on the periphery of the paper roll building up around a reel spool 11. Reference numeral designations 11C - 11E indicate different stages or positions of a reel spool 11 during winding. A reel spool at 11E is supported and rotates on two support tracks 12, while secondary forks 13 press it against the reel drum 10. The secondary forks also move the paper roll off and away from the reel drum 10, when it reaches the desired diameter. As mentioned, various positions of the reel spool 11 are designated by 11A,11B,11C,11D or 11E depending on the phase of winding it is in. 11E shows the reel spool just before it is removed from the support plates, but is still supported on them. After the removal of the fully wound reel spool, the secondary forks 13 press the subsequent reel spool into a nip contact with the reel drum 10. The designation 11 is used when referring to the reel spool in general and no specific position is referred to. The fully wound paper rolls are transferred to the left for further treatment along the support tracks 12, after which the empty core shafts are returned by means of, e.g., a bridge crane onto storage tracks 16 located to the right in the drawings and above the support tracks 12. Primary forks 14 constitute the exchange means of the reel spools 11. When changing reel spools 11, the primary forks 14 are elevated to their upper position. The shape of the primary forks 14 and the pivoting point 15 have been chosen in the way that, when elevated, they pick up an empty reel spool 11B from storage frame 16. The upper surface of the storage frame is inclined towards the exchange point of the reel spools in order to enable a new reel spool 11A to roll to a point where it is ready to be picked up by the primary forks 14 when it is again time to change reel spools. Support plates 17 are attached to the primary forks 14, which support the reel spool during the various stages 11B-E on which the paper roll is built-up. The primary forks 14 are now lowered to allow the periphery of the reel spool at 11C to approach the periphery of the reel drum 10 and the distance between the reel spool at 11C and the reel drum 10 diminishes further until the reel spool, which has been preaccelerated and reached approximately the same peripheral speed as the reel drum, touches at 11C the paper web W running on the reel drum 10 and reaches the exact peripheral speed of the reel drum. The transfer of the web W can now be carried out in a manner known per se, and a new reel spool 11 can be lowered onto the support tracks 12 replacing the removed spool 11. At stage 11C, where the reel spool presses against the web, the exchange of reel spools is carried out and in many prior art solutions a break in the web is produced for about half a minute. In this solution the new reel spool at 11C can start receiving web while the previous spool is still in nip contact with the reel drum 10, if the web is being cut by using a sharp-pointed object to make a hole in the web before blowing, or the use of an edge blowing method or a cord cutting device (prior art techniques). If again the cutting of the web is performed by pocket blowing (medium or thick paper grades), the nip contact with the full machine roll 11E has to be disengaged first and only then can the web be cut off. In any case, when using the solution according to the invention, the exchange is carried out in the speediest possible manner and the amount of wastage resulting from the breaking and change-over, referred to as "broke", is minimised. Fig. 2. shows the various stages 11A,11B,11C,11D,11E of the reel spool 11 when it is being transferred onto the support tracks 12, supported on the support plates 17 by the primary forks 14. During stages 11C-11E the support angle of the support plates 17 adjusts itself in such a way that the contact pressure between the spool 11 and the reel drum, while lowering the primary forks 14, remains essentially constant. The support plates are pivotally mounted on the primary forks 14 and shaped in such a way that while the primary forks are in their lower position and the reel spool at 11E is on the roll tracks 12, the support plates 17 pivot round their pivot point 18 into such a position on the primary forks 14 that the primary forks 14 can be elevated back into the upper position and passing the the reel spool 11E supported on the tracks 12. In the embodiment according to the drawings, the pivoting of the support plates 17 is accomplished by making the portion of the support plate to the right-hand side of the pivot point 18 heavier than the left hand side portion. When each primary fork has been lowered as far as the tracks 12, it continues turning downward until its support plate 17 can tip over from behind the reel spool into a fixed position whereby it can be displaced past the reel spool at 11E back into the upper position, when the forks are raised. This solution can, when desired, be replaced by a mechanical or hydraulic movement, which produces the same result but is more costly. The primary forks 14 are arranged to function simultaneously, for example, by means of a synchronizing shaft 21, which is disposed outside the pivot points 15 by means of connecting rods 23 in order to decrease the moment applied to the shaft 21 in proportion to the transmission ratio. The relief force required by some web materials is achieved by a relief cylinder 22, which is disposed in the upper portion of the primary forks 14 directly beneath the bearing housings of the reel spool at 11B. The pressure is set while the primary forks are in the upper position, and is kept constant while the primary forks move from the upper position to the lower. In the following, the functioning principle of the support plates constructed in accordance with the invention is described in more detail referring to Fig. 2. According to the invention, the contact pressure is achieved in the nip contact between the reel spool 11 and the reel drum 10 due to the weight of the spool 11B-E itself. When the reel spool 11 moves downwards while the primary forks are being lowered, the action of the gravity force on it is directly vertical, which force is represented by vector B. This force acting on the spool is divided into two force components, of which one, A, is the contact force between the reel spool and the reel drum. The force A remains almost constant during the entire downward movement of the primary forks. References C1,C2 and C3 designate the size of the force component that together with vector A constitutes the sum vector B. The force component C1,C2 and C3 is determined by the contact angle of the counter surface of the support plate 17, which in turn is determined in such a way that the force component A in the vector sum A + C = B is almost always the same in the various positions of the reel spool 11. Line D in Fig. 2 is the line that represents the position of the counter surface of the support plate, against which the reel spool is supported, in other words, against which vector C is right-angled. The contact force A remains almost constant during the lowering stage. At the point where the support plates transmit the reel spool onto the secondary arms 13, the support plates are mechanically synchronized by means of a synchronizing shaft 21. This is to prevent uneven load when the secondary load is engaged, and thus maintain the web even and unwrinkled, which considerably decreases the amount of "broke", since any failure at the initial stage of winding would result in an interruption of the winding operation and unwinding of the roll into "broke". It has to be pointed out that the invention is by no means limited to the embodiment presented above, but the details may vary a great deal within the scope of the inventional concept. The support plates may, for instance, be of a curved shape or the bearing housings of the reel spool may have various diameters thus disposing the support point of the suppot plates at different points of the support plate. By this technique, the control of the pressure force can be achieved in a similar way as by adjusting the support angle of a straight support plate, such as described above. In the following the patent claims are presented, which define the inventional concept within the scope of which the details of the invention may vary.

Claims: A method for on-machine winding of a web, in which method a Pope reel drum (10) or corresponding reeling means is used, over which the web (W) to be wound is conducted and in which method new, empty reel spools (11) are brought into contact with the reel drum (10), after which the web (W) is conducted from a previous, fully wound reel to be wound onto a new reel spool (11), and wherein the contact pressure between the reel spool (11C-11E) and the reel drum (10) is maintained substantially constant characterized in that the method comprises, in combination, the following steps: a. picking-up an empty reel spool (11A,11B) by means of primary forks (14) when in the upper position and without any auxiliary equipment whereby said empty reel spool (11A,11B) rolls onto said primary forks; b. with the empty preaccelerated reel spool (11B, 11C) being guided by the primary forks (14) and supported on support plates (17) attached to the primary forks (14), bringing said reel spool into nip contact with the rotating reel drum (10), through which nip the web (W) to be wound runs and is wound around the reel spool (11) at this nip contact, with the support plates (17) being selected of such shape and being retained in such a position during the lowering of the primary forks (14) to ensure substantially constant contact pressure is maintained while the primary forks (14) move from their upper position to their lower position; c. wherein the contour surface of the support plate (17) is selected or designed as to have a support angle such that the support plate vector (C1;C2;C3) which is a component of the vertical vector (B) representing the force of gravity on the reel spool (11) is at right angles to the tangent (D) through the point of contact between the supporting counter surface of the supporting plate (17) and the reel spool (11), and such that the drum contact force vector (A) which is the other component of the vertical vector (B) remains constant or substantially constant during the entire lowering movement of the primary forks (14); and d. with the primary forks (14) being in their lower position, turning the support plates (17) into such a position that they pass the reel spool (11), already supported on the reel tracks (12), as the primary forks (14) move back to their upper position, and, as required, repeating the mentioned steps when it is time to change reel spool again and the support plates (17) are ready for receiving one. The method according to claim 1, characterized in that the turning of the support plates (17) about an attachment point (18) is accomplished either by the force of gravity, or by means of a spring and/or a hydraulic or pneumatic cylinder. The method according to claims 1 and 2, characterized in that the support point of the support plates (17) can be disposed at different points of the support plates by giving the supporting surfaces of the support plates a curved shape and/or designing the bearing housings of the reel spool with various diameters, thus achieving a partial or total control of the pressure force. An apparatus for on-machine winding of a web (W) coming from a paper machine or corresponding web- (W) making machine onto reel spools (11), which apparatus comprises a driven reel drum (10) and primary forks (14) associated therewith and which bring empty reel spools (11A) from a storage frame (16) for storing the empty reel spools (11A), ready to be picked up by the primary forks (14) without any auxiliary equipment, to the reel drum (10) and tracks (12), supported on which the web roll, at least in the final stage of the winding, builds up, and wherein the contact pressure between the reel drum and the reel spool remains substantially constant regardless of the height position of the reel spool, characterized in that - support plates (17) are attached to the primary forks (14), and an empty reel spool (11B, 11C) is supportable thereon and can be brought into nip contact with the rotating reel drum (10) by lowering the primary forks (14), said support plates (17) being provided with a counter surface whose shape and position is such that when lowering the reel spool, said substantially constant contact pressure is maintained; said substantially constant contact pressure being maintained by the contour surface of the support plate (17) having a support angle such that the support plate vector (C1;C2;C3) which is a component of the vertical vector (B) representing the force of gravity on the reel spool (11) is at right angles to the tangent (D) through the point of contact between the supporting counter surface of the supporting plate (17) and the reel spool (11), and such that the drum contact force vector (A) which is the other component of the vertical vector (B) remains constant or substantially constant during the entire lowering movement of the primary forks (14). The apparatus according to claim 4, characterized in that the contact pressure is selected to suit each paper grade by selecting an appropriate counter surface of a support plate (17) or other means. The apparatus according to claims 4 or 5, characterized in that the support plates are either exchangeable or fixed. The winding apparatus according to any of claims 4 - 6, characterized in that the surface of the storage frame (16) is inclined towards the primary forks (14) in such a way that a new reel spool (11A) rolls into the place of a preceding one when such has been picked up for winding. The apparatus according to any of claims 4 - 7, characterized in that the turning of support plates (17) about the attachment point (18) is accomplished either by the force of gravity, the centre of gravity of the support plates, by means of a spring and/or its respective hydraulic cylinders. The apparatus according to any of claims 4 - 8, characterized in that the supporting surfaces of the support plates (17) have been given a curved shape for selecting the centre of gravity of the support plates (17) in order to control the pressure force. The apparatus according to any of claims 4 - 9, characterized in that the diameter of the bearing housings of the reel spool may be suitably selected in order to control the pressure force.

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