GB2138404A - Winding apparatus, process and product - Google Patents

Abstract

Winding turret for continuous plastics film (1) comprises a laying-on roller (2) alongside a freely rotatable turret (4) carrying a plurality of releasable rotatable winding cores (3a, 3b, 3c, 3d) mounted at equiangularly spaced locations on the turret. The turret is freely rotatable about a spindle (5a) carrying pinions (5) engaging with inclined racks (6) so that the turret moves up the racks away from laying-on roller (2) during winding to allow gravity-biased indexing of the turret. When a core is fully wound a slide block (15, see Fig. 3) is withdrawn from an associated pin (22a-22d) on the turret to allow it to rotate under gravity and bring a new core against the laying on roller. The core is removed and replaced by axially sliding its supporting mandrel out of the core (see Fig. 2). <IMAGE>

Description

SPECIFICATION Winding apparatus, process and product The present invention relates to winding appa ratus for winding continuous material onto a succession of different rotatable winding cores, substantially without interruption to the flow of continuous material.

In particular, the invention has utility in the field of winding up plastics film onto indivi dual winding cores of various lengths.

Hitherto, in the manufacture of plastics film, the material has been wound up in bulk in the manufacturing plant on to large winding cores (in one instance winding cores having a dia meter of 76 mm) to provide relatively large packages of the plastics material, and then subsequent re-winding has been necessary in order to transfer the plastics film from the larger winding cores to smaller, more mana geable winding cores for consumer use (in one example cores of 40 mm diameter).

It is an object of the present invention to provide winding apparatus which enables an operator to manipulate both loaded and empty rotatable winding cores to take up continuous material being delivered from a source.

According to one aspect of the present invention there is provided winding apparatus for winding up continuous material on rotatable winding cores, comprising: a laying-on roller about which the continuous material passes during rotation of the laying-on roller in use of the apparatus; a rotatable turret carrying support means for several such rotatable winding cores each intended to receive the continuous material passing over said laying-on roller; and means for withdrawing said turret away from the laying-on roller, as desired, for indexing rotation of the turret after completion of build-up of continuous material on a said winding core on the turret, wherein the turret is freely rotatable about its axis of rotation when withdrawn from the laying-on roller, and the arrangement is such that indexing rotation can be prevented when said turret has not been withdrawn from said laying-on roller.

Preferably said means for withdrawing the turret from the laying-on roller includes an inclined guide along which a central spindle of the turret is able to move, and means for moving said central spindle of the turret along said inclined guide.

Advantageously the apparatus includes a lost motion connection to allow a said rotatable winding core carried by the turret alongside said laying-on roller to move away from the laying-on roller as the buiid-up of continuous material on said carried winding core grows.

A further asp ct of the invention provides a process for winding continuous flat plastics film, comprising feeding said film over a rotating laying-on roller; positioning a first winding core or set of winding cores on a turret close enough two said laying-on roller to be rotated thereby as said continuous film between said laying-on roller and said first core or cores winds onto said first core or cores; mounting a second winding core or set of winding cores on said turret at a position displaced from said first winding core or cores; when build-up of said continuous film on said first core or cores has reached a desired magnitude, indexing said turret by withdrawing the turret away from the laying-on roller and allowing the turret to index under the effect of the asymmetric weight of the loaded first core or cores to bring the second core or cores into said laying-on roller with the said continuous film which passes over said laying-on roller pressed against the second core or cores; severing the run of continuous film between said first core or cores and said second core or cores, whereby continued rotation of said laying-on roller causes said continuous film to build up on said second core or cores rotated thereby; and removing said loaded first core or cores from the turret during the growth of the build-up on said second core or cores.

The invention also provides plastics film wound by the process of the second aspect In order that the present invention may more readily be understood the following description is given, merely by way of example, with reference to the accompanying drawings in which: FIGURE 1 is a side elevational view of a holder turret for rotatable winding cores to receive extruded plastics film; FIGURE 2 is a view of the apparatus of Figure 1, taken from the lefthand side thereof; FIGURE 3 is a side view, in simplified form, showing the mechanism for withdrawing the turret to a position allowing indexing of the winding cores for the plastics film; and FIGURE 4 is a view of the apparatus of Figure 3, seen from the lefthand side thereof.

Continuously extruded tubular film material, extruded by the so-called "bubble extrusion" method, is slit open and pressed flat and supplied to a wind-up station where the flat film 1 passes over a laying-on roller 2 where it is applied to the surface of a stiff cardboard winding core 3b supported on a turret, generally referenced 4. The turret is shown as comprising further winding cores 3a, 3e and 3d, arranged at 90 intervals around the axis of rotation of the turret 4, defined by a central support spindle 5a supported at each end by a pinion 5 rolling on a rack 6. The rack 6 and pinion 5 at each end of the spindle 5a ensures that the support spindle 5a remains parallel to the axis of rotation of the laying-on roller 2.The racks 6 and pinion 5 may, if desired, be replaced by a plain surface on which a roller, or even the end of the spindle 5a, rolls.

The turret is periodically allowed to index under the weight of the build-up of plastics material on the winding core 3b but is otherwise held against such rotation by one of four pairs of pins 22a, 22b, 22cor 22dwhich abut the underside of the upper ends of the racks 6 or outer slots 24 (Figure 3) in movable slide blocks.

Although in Figure 1 only one winding core 3a, 3b, 3c, 3d is shown at each of the four core support stations, there are in fact several such cores (in this case two) mounted to either side of a centre plate 7, the ends of the turret being defined by two end plates 8 between which the turret centre plate 7 is disposed. Thus, as film is wound up on the two winding cores 3b, there is simultaneous build-up of film on the two separate winding cores at that station, the film coming from a common source and having been slit along its centre line to pass to either side of the gap between the two parallel collinear winding cores 3b (occupied by the turret central plate 7).

Figure 2 shows one side of the turret as comprising a turret end plate 8 at the lefthand side of the drawing, and the turret centre plate 7 near the righthand side. This implies that the turret is generally symmetrical about this turret centre plate 7 and continues to the righthand side of the centre plate 7 to define the second half of the turret.

At the lefthand end of the spindle 5a one of the two pinions 5, which meshes with the supporting rack 6 (omitted from Figure 2), can be seen.

Pivoting of a core mandrel clamping lever 9,operating by means of a mechanism, which is shown in Figure 2 but need not be described in detail in the present application, allows the lefthand core mandrel 10 to be withdrawn leftwardly from within the winding core 3c to allow the winding core at the lefthand side of the turret to be removed once a build-up 1 2 of plastics film has formed thereon. It will be understood that the core mandrel 1 3 supporting the other end of the core 3c is fixed on the turret centre plate 7, and that a further core mandrel 11, again fixed against axial movement but allowed to rotate freely, is mounted on the opposite side of the turret centre plate 7 to support a further winding core 3c (not shown) to the righthand side of the centre plate 7.A core mandrel clamping lever and mechanism, similar to that shown at 9 for the lefthand winding core 3b, is provided at the righthand side to allow release of the second winding core 3c.

The lefthand end of the laying-on roller 2 is shown in Figure 2, and from this it will be understood that the two turret end plates 8 are clear of the ends of the laying-on roller 2 whereas the turret centre plate 7 (being much smaller in side view-as shown in Figure 1) is generally in line with the centre of the layingon roller 2.

Figure 3 shows one of two support plates 14, each carried by a respective one of the stationary racks 6, slidably supporting a pair of slide blocks 1 5 each of which has a recess 1 6 receiving a generally cylindrical end 1 7 of an actuating lever 18 pivoted on lay shaft 1 9.

The lay shaft 1 9 is rotated by means of a common actuating handle 20 and the shaft is spring-biased clockwise by two springs 21 each having one end fixed to a boss 21 a carried by the respective lever 1 8 and its other end fastened to a boss 21 b carried by the respective mounting plate 14.

Each of the turret end plates 8 includes the four equiangularly spaced pins 22a, 22b, 22c and 22d (Figure 1 ) extending axially outwardly of the turret 4 adjacent the four cores 3a, 3b, 3cand 3d.

Each slide block 1 5 includes an open ended slot 24 to receive the associated pin, in this case pin 22d carried at each end of the turret so that, as the turret naturally climbs up the racks in response to build-up of plastics film on the winding cores 3b, the slide blocks 1 5 can remain stationar but allow movement of the pins 22d relative thereto.

As can be seen from Figure 3, when(in response to an indication by a winding meter that adequate film has been wound onto the core 3b) the operator pivots the levers 1 8 in the anticlockwise direction, by manipulation of the actuating handle 20 against the biasing action of the springs 21, the two slide blocks 1 5 move leftwardly relative to the mounting plates 14 to release the pair of collinear pins 22d at a core, e.g. core 3d in Figure 1, and release those pins to free the turret for clockwise rotation under the gravity biasing effect of the full cores 3b.

This movement automatically brings the empty core 3a down onto the laying-on roller 2 to start winding onto that core. The turret will however need to be manipulated by the operator to complete the indexing rotation.

However, this last mentioned manipulation may, if desired, be mechanised by suitably modifying the machine.

Alternatively, gradual separation of the winding cores 3a, 3b, 3c,3dfrom the layingon roller 2 may be provided for by supporting the cores on the turret in such a manner that they can be displaced radially of the turret as the build-up grows (by virtue of four separate lost motion connectionsone for each pair of cores). The racks 6 and the turret movement they allow would then be redundant.

Figure 4 shows the apparatus of Figure 3, viewed from the lefthand side, and illustrates the lay shaft 1 9 which extends along the full axial length of the turret between lefthand and righthand levers 18 of the turret. As can be seen from Figure 4 there is only one actuating handle 20 to control rotation of the shaft 19 and the two levers 18.

Figure 4 furthermore shows the channel section grooves 25 which receive the slide blocks 1 5 and permit the slide blocks 1 5 to move relative to the support plates 14, in a direction parallel to the extent of the racks 6.

The operation of the apparatus shown in Figures 1 to 4 is as follows: Initially the turret 4 will have two winding cores 3b (in the position referenced 3a in Figure 1), but will be free of winding cores 3a, 3cand 3dand there will be no supply of plastics film 1 over the laying-on roller 2.

The actuating handle 20 is then manipu lated in the anticlockwise direction to with draw the slide blocks 1 5 leftwardly as shown in Figure 3, and the turret is manipulated up to the racks 6 until the pins 22 move clear of the upper ends of the racks 6 to allow the turret to be indexed in the clockwise direction to bring the cores 3b down towards the surface of the laying-on roller 2. At this stage the turret is released to roll down the racks 6 and thus the cores 3bwill rest on the top of the laying-on roller. To complete the indexing of the turret to the Figure 1 position it is moved slightly up the racks to allow the cores 3b to descend and meanwhile the pins 22d will be allowed to rise to abut the underside of the upper end of the racks 6 as shown in Figure 1.The springs 21 biasing the actuat ing handle 20 in the clockwise direction move the slide blocks 1 5 down to await rising of the turret pins 22 as film begins to build up on the two winding cores 3b in rolling contact with the surface of the laying-on roller 2.

The extruder is then started up and the plastics film arrives at the surface of the laying-on roller 2 which is driven for rotation to entrain movement of that film 1 and the film is then guided manually onto the surface of the winding cores 3b. From then on the continued rotation of the laying-on roller 2 will entrain rotation of the winding cores 3b to continue build-up of plastics film on the wind ing cores 3b. While this build-up is in progress, a second pair of winding cores 3a is attached to the position shown in Figure 1, ready for indexing of the turret 4 when desired.

As the build-up occurs on the first cores 3b, the turret will climb up the inclined racks 6 until the build-up occupies the position shown schematically by the circle 26 in Figure 1. It will be appreciated that during this time the slide blocks 1 5 will have remained stationar but the pins 22 have been able to move leftwardly as viewed in Figure 3 clearing the ends of the racks 6 and entering the slots 24.

When the build-up of plastics film on the first cores 3b has reached the desired quantity, the actuating handle 20 is moved in the anticlockwise direction to withdraw the slide blocks 1 5 thereby releasing the turret to rotate clockwise to allow the build-up of plastics film on the first winding cores 3b to drop out of frictional contact with the laying-on roller 2 as the weight of the two first winding cores 3b, the two second winding cores 3a, and the build-up existing on each of the two first cores 3b generates a clockwise moment on the turret 4, causing it to index to bring the second winding cores 3a down towards the position previously occupied by the first winding cores 3b. As the turret 4 thus rotates, the control handle 20 is released to move in the clockwise direction.The turret continues to rotate until the second winding cores 3a contact the laying-on roller 2. The turret is then manipulated to allow the second winding cores 3a to pass the laying-on roller to complete 90 of indexing rotation when the pins 22c strike the underside of the racks 6.

During this indexing motion, the continuous plastics film will have been caused to stretch over the cylindrical surfaces of the second winding cores 3a on its run between the laying-on roller 2 and the first winding cores 3b (which now occupy the position previously occupied by the cores 3e of Figure 1). It is a simple matter to cut the run of the plastics film between the first and second winding cores 3b and 3a so that the film will then become attached to the second winding cores 3a which are now driven for rotation by frictional contact with the rotating laying-on roller 2; thus build-up of plastics film on the cores 3 a will begin.

The operator can then, at his or her leisure,remove the first winding cores 3b by manipulation of the core mandrel clamping lever 9 for the movable core mandrel holding each of those winding cores, and put those loaded winding cores away in a storage location.

Fairly soon (before the build-up of plastics film on the winding cores 3a has reached the desired quantity) a third pair of winding cores 3d is mounted on the turret 4 but in the position previously occupied by the second winding cores 3a before the indexing which has just been described.

By continued operation, using the cycle just described, it is possible for the continuous supply of slit plastics film from the extruder to be wound onto a succession of separate pairs of cores, and for those winding cores (when loaded) to be readily removed by the operator while the turret is in a static configuration and build-up on a fresh pair of winding cores is in progress. This allows maximum safety to the operator who gains access from the lefthand side of the turret as viewed in Figure 1 and is nowhere near the rotating laying-on roller 2 during the winding core removal operation, and can equally remain well clear of the laying-on roller 2 during the operation of attaching the next pair of empty winding cores before next indexing.

In order to generate the maximum clockwise indexing moment, the turret 4 will only carry a maximum of three sets of wind ing cores at one time, the part of the turret projecting to the lefthand side of Figure 1 (that shown in Figure 1 as being occupied by winding cores 3d) being left devoid of wind ing cores so that indexing will occur positively once the slide blocks 1 5 have been withdrawn to release the turret for rotation.

Claims (14)

1. Winding apparatus for winding up continuous material on rotatable winding cores, comprising: a laying-on roller about which the continuous material passes during rotation of the laying-on roller in use of the apparatus; a rotatable turret carrying support means for several such rotatable winding cores each intended to receive the continuous material passing over said laying-on roller; means al lowing travel of said turret away from the laying-on roller in response to build-up of continuous material on a said winding core on the turret; and a releasable stop to prevent indexing rotation of said turret after the turret has been withdrawn from said laying-on roller; wherein the turret is freely rotatable about its axis of rotation when withdrawn from the laying-on roller and said stop is released and the arrangement is such that indexing rotation is prevented until said turret has been withdrawn from said laying-on roller.

2. Winding apparatus according to claim 1, wherein said means for allowing the turret to travel away from the laying-on roller includes an inclined guide along which a central spindle of the turret is able to move.

3. Winding apparatus according to claim 2, and including a further stop effective to prevent rotation of the turret in an indexing direction until the turret has moved away from the laying-on roller during yarn build-up on a said core.

4. Winding apparatus according to claim 3, wherein said inclined guide comprises a pair of parallel, spaced racks, and wherein said central spindle carries at or near its ends pinions each engaging with a respective said rack.

5. Winding apparatus according to claim 4, when appendant to claim 3, wherein said second stop comprises an abutment member on the turret engaging under the upper end of at least one of the racks to prevent rotation of the turret in a direction corresponding to raising of said pin until the pin has moved clear of the upper end of said rack.

6. Winding apparatus according to any one of claims 1 to 5, wherein said releasable stop includes a lost motion connection to allow a said rotatable winding core carried by the turret alongside said laying-on roller to move away from the laying-on roller as the build-up of continuous material on said carried winding core grows but nevertheless prevents rotation of the turret in either direction until released.

7. Winding apparatus according to claims 2 and 6 together, wherein said lost motion connection allows said turret central spindle to climb said inclined guide in response to buildup of said continuous material on said carried rotatable winding core but said releasable stop member is effective to stop indexing rotation of the turret until the stop member is released.

8. Winding apparatus according to any one of the preceding claims, wherein said turret comprises four equiangularly spaced core supports for said rotatable winding cores, and each of said equiangularly spaced core supports includes means for supporting at least two of said rotatable winding cores in collinear configuration.

9. Winding apparatus according to claim 7, wherein each said core support comprises means for supporting at least two of said rotatable winding cores freely rotatably with respect to the turret.

10. Winding apparatus according to any one of claims 1 to 9, when mounted alongside a continuous extruder for plastics film, and arranged to wind said film onto a succession of winding cores.

11. Winding apparatus substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.

12. A process for winding continuous flat plastics film, comprising feeding said film over a rotating laying-on roller; positioning a first winding core or set of winding cores on a turret close enough to said laying-on roller to be rotated thereby as said continuous film between said laying-on roller and said first core or cores winds onto said first core or cores; mounting a second winding core or set of winding cores on said turret at a position displaced from said first winding core or cores; when build-up of said continuous film on said first core or cores has reached a desired magnitude, releasing the turret thereby allowing the turret to index under the effect of the asymmetric weight of the loaded first core or cores to bring the second core or cores into said laying-on roller with the said continuous film which passes over said layingon roller pressed against the second core or cores; severing the run of continuous film between said first core or cores and said second core or cores, whereby continued rotation of said laying-on roller causes said continuous film to build up on said second core or cores rotated thereby; and removing said loaded first core or cores from the turret during the growth of the build-up on said second core or cores.

1 3. A process according to claim 12, wherein said turret holds two said first cores and two said second cores at angularly spaced locations and has supports for further sets of two cores each at other angularly spaced locations, and said film is delivered from an extruder and is slit before passing over said laying-on roller.

14. A process of winding plastics film substantially as hereinbefore described with reference to the accompanying drawings.

1 5. Plastics film wound by the process of claim 12, 13 or 14.