WO2015067946A2

WO2015067946A2 - Winding method and apparatus

Info

Publication number: WO2015067946A2
Application number: PCT/GB2014/053299
Authority: WO
Inventors: Keith Fordham
Original assignee: Ashe Controls Ltd
Current assignee: Ashe Controls Ltd
Priority date: 2013-11-06
Filing date: 2014-11-05
Publication date: 2015-05-14
Anticipated expiration: 2016-05-06
Also published as: GB2520244A; WO2015067946A3; GB201319616D0; GB2520244B

Abstract

An apparatus (1) for winding a sheet material has a reel onto which a web of the sheet material (2) is to be wound; a wrap roller (11) which is movable relative to the reel to deflect a running web to run between the wrap roller and the reel and then around a portion of the circumference of the reel; a cutter (5) for cutting the web at a pre-determined point downstream of the reel and inserting the cut end of the web between the reel and the wrap roller; and a turret (3) on which the reel is mounted. A controller variably rotates the turret, depending on the diameter of the reel, to align the cutter to cut at the pre-determined point downstream of the reel.

Description

WINDING METHOD AND APPARATUS

This invention relates to a method and an apparatus for winding sheet material. After processing, sheet feed materials are required to be wound onto easily managed rolls. These are commonly wound onto cardboard cores of 3" (76mm) l/D (internal diameter) but cores can vary in bore diameter and wall thickness and the material from which they are manufactured. The width of the core is selected to suit the sheet product width and for cosmetic or process purposes it is desirable to have the edges of the sheet material aligned accurately with the edge of the core.

Some products are alternatively wound to form a roll with a pre-determined inside diameter with no supporting core and need to be easily removed from the winding mandrel when finished.

Typical sheet material products have widths from 30mm to 1600mm, but product widths outside this range do exist. Bulk, single sheet, materials can be processed in a rewinding machine though many materials are also slit longitudinally during rewinding to avoid unnecessary further processing. This process is commonly called slitting and rewinding.

Rewind roll diameters may vary from finished slit rolls of 50mm diameter to bulk rolls of 1000mm diameter and more.

Many processes carried out on sheet materials, such as printing, coating etc, benefit from having a constant running speed, or web speed, therefore requiring the changeover from one rewind reel to the next at the output of a processing machine to be done at speed. Machines are available to do this for slow web speeds, or while the web speed is slowed temporarily, and are generally designed to have multiple rewind shafts mounted on a turret which rotates about a centre point to bring an empty shaft into the running web path and which use a varying array of designs to cross-cut the web and to transfer the material onto the empty shaft while the material is still running. A typical web speed is 200 metres per minute (mpm) but this can vary from a few mpm to 300 mpm. Faster web speeds have been achieved but are unusual.

EP1295831A1 describes a system in which the output reel onto which the web is wound after processing may be changed without stopping or even slowing down the web of material running through the machine. The machine has a turret on which four shafts are mounted. The turret is able to rotate between four fixed positions, such that each shaft can be placed in a transfer position, a running position, an offload position or a core load position. An empty core (i.e., a core around which no sheet material has been wound) is arranged on the shaft in the transfer position to receive the web when a desired amount of web material has been wound around a core arranged at the running position. A wrap roller is moved to draw the web upstream of the core at the transfer position, around a portion of the circumference of the core. A cutter cuts the web at a specific point between the wrap roller and the core and forces the end of the web into the in- running nip between the wrap roller and the core.

It is often desirable for a winding machine to wind sheet material around cores of varying diameter, say from 25mm to 150mm. However, for conventional machines, such as the machine described in EP1295831A1 , a number of mechanical adjustments must to be made in order to handle varying core diameters. For example, if the diameter of the core changes, then the position of the cutter must be manually adjusted to ensure that cutting occurs in the correct position. However, the manual adjustment requires a high level of technical expertise and experience, and often requires a degree of trial and error which can delay manufacture and result in wastage of sheet material. Furthermore, when accommodating different core diameters, the position of the wrap roller must also be recalculated and independently adjusted, adding to machine configuration times. Consequently, there is a desire to simplify winding machinery and to decrease the time required to handle changes in core diameter. SUMMARY OF INVENTION

The invention provides a method and an apparatus for winding a sheet material as defined in the appended independent claims. Advantageous or preferred features are set out in the dependent claims.

Accordingly, the method may comprise deflecting the path of a running web of the sheet material to run between a wrap roller and a reel onto which the web is to be wound, and then around a portion of the circumference of the reel. The method may also comprise variably rotating a turret on which the reel is mounted, such that the reel is moved to a transfer (or cutting) position at which the cutter is positioned or aligned to cut the running web at a pre-determined point

downstream of the reel. The degree or amount of turret rotation required to effect, or configure, the transfer position may thus be dependent on the diameter of the reel. In other words, variably rotating the turret may adjust the position of the rotational axis of the reel depending on the reel diameter. The method may also comprise cutting the running web, using the cutter, at the pre-determined point downstream of the reel, between the reel and the wrap roller and inserting the cut end of the web between the reel and the wrap roller.

Thus, advantageously, the invention may accommodate variable reel or core diameters, without requiring adjustment of the cutter configuration. The extent or depth to which the cutter projects to cut the sheet material may effectively be fixed. The cutter may be said to have a fixed firing position. Rather than adjusting the cutting depth, the present invention may vary the position of the reel such that the cutter cuts at the desired site. The axis of rotation of the reel, when in the transfer position, may thus be variable depending on the size of the reel. For example, if the reel diameter is smaller, the turret may rotate to position the axis of the reel nearer to the cutter. Conversely, if the reel diameter is larger, the turret may rotate to position the axis of the reel further from the cutter. The axis of the reel may be variable such that a portion of the outer edge of the reel remains in a substantially consistent position with respect to the cutter, for reels of varying diameter. Variable rotation of the turret may align the cutter with the pre- determined point downstream of the reel, which may be an in-running nip between the reel and the wrap roller.

In EP1295831 A1 , the rotation of the turret is not variable as it can only rotate in successive 90° rotations between four distinct or discrete rotational

configurations. The turret is sequentially locked in each of these positions. In contrast, rotation of the turret according to the present invention may be variable (or progressively or continuously variable), such that the reel is effectively positionable in any orientation around the turret. This may provide greater flexibility to the user and may simplify the machinery, as the apparatus may not require a means for adjusting the cutter configuration.

The cutter may be movable or translatable between a first (or non-cutting) position in which the cutter is not able to cut the running web and a second (or cutting) position in which the cutter is able to cut the running web. For example, the cutter may be mounted on a translating carriage which moves the cutter between the non-cutting and the cutting positions. In the non-cutting position, the cutter may be further from the reel and further from the turret than when the cutter is in the cutting position. The translating carriage may move the cutter along a translating plane. For example, the translating carriage may be mounted on a track or rail, which is preferably substantially flat or planar. The track or rail may be arranged substantially horizontally, in use. In the non-cutting position, the cutter may be sufficiently spaced from the reel and/or from the turret such that it does not obstruct or impair rotation of the turret. The cutting position of the cutter may be fixed, or controlled such that it is fixed. In other words, the translating carriage may not translate to a greater or lesser extent depending on the diameter of the reel. Regardless of the reel size, the cutter may translate to substantially the same cutting position each time the sheet material is cut. So, all necessary adjustments to position the cutter in the correct position relative to the reel, and to align the cutter with the pre-determined point downstream of the reel, may be achieved by variably rotating the turret.

The wrap roller may be rotatably mounted at the end of a pivoting arm or cam. The rotational position of the pivoting arm may be adjustable by a biasing or urging means, such as a pneumatic driver. The pivoting arm, and the biasing means, may be mounted on a translating carriage. The translating carriage may be driven by a controllable driver. For example, it may be pneumatically driven. A wrap roller assembly may comprise the wrap roller, the pivoting arm and the biasing means.

The pivot and the carriage may be under computer control such that the wrap roller may be positionable in an appropriate position for cutting. A computerised controller may thus vary the position the wrap roller depending on the diameter of the reel, for example by extending or contracting the biasing means.

However, in a preferred embodiment, the position of the wrap roller may be affected by the variable rotation of the turret. For example, as the reel moves into the transfer position, it may engage the wrap roller and exert a force on it, such that the pivoting arm rotates about its pivot. The extent of the rotation at the pivot may vary according to the diameter of the core. For a reel with a larger diameter, the extent to which the pivoting arm rotates may be greater than for a reel with a smaller diameter. Advantageously, this may mean that the position of the wrap roller is automatically adjusted on rotation of the turret. There may be no requirement to actively adjust the position of the wrap roller, for example by reprogramming the computerised controller to alter the extension or contraction of the biasing means. The biasing means may thus simply comprise a resilient biasing means, such as a spring. The extent to which the wrap roller moves may be dependent on the rotation of the turret, with the rotation of the turret being dependent on the diameter of the reel.

The wrap roller may be movable or translatable between a first or inactive position in which the wrap roller is not able to engage the reel, and a second or active position in which the wrap roller is able to engage the reel. For example, the wrap roller assembly may be mounted on a translating carriage which moves the wrap roller between the inactive position and the active position. The translating carriage may be as described above. In the inactive position, the wrap roller may be sufficiently spaced from the reel and/or the turret such that it does not obstruct or impair rotation of the turret. In a particularly preferred embodiment the translating carriage on which the wrap roller assembly is mounted is the same translating carriage on which the cutter is mounted. So, movement of the cutter may be coupled to movement of the wrap roller. Advantageously, this may simplify operation because there may be no requirement to independently adjust the position of the cutter and the position of the wrap roller. The turret may be rotatable in a first, forward direction and in a second, reverse (or backward) direction. So, the method may comprise rotating the turret in both the first and second directions when, for example, the running web of the sheet material is being transferred from one reel to another. This is in contrast to the apparatus described in EP1295831A1 , in which rotation of the turret between the four, fixed orientations only occurs in a single, forward direction. Being able to variably rotate the turret in a forward and reverse direction may allow a precise positioning of the reel.

In a preferred embodiment, a plurality of reels is mounted on the turret. There may be at least three or at least four reels. Preferably, there are four reels.

Having a plurality of reels may mean that as the running sheet of web material is being wound around a first reel, a second reel may be positioned in preparation for transferring the sheet material from the first reel to the second reel. As described in EP1295831 A1 , the presence of more than two reels, such as four reels, may mean that wound sheet material may be off-loaded , and/or a reel may be prepared for transfer, without having to stop or slow the machine. At any one time, a maximum of two reels may be involved in winding and transfer.

The method may comprise two general stages, or phases: a winding (or running) stage; and a transfer stage. The apparatus may be controlled, for example by a computerised controller, to proceed through these stages, in use.

During the winding stage, the running web of sheet material may be wound around a first reel to create a roll of the sheet material around the first reel. The cutter is preferably in the non-cutting position and the wrap roller is preferably in the inactive position. Only the first reel may be in contact with the running web of the sheet material.

In the transfer stage, the running web of the sheet material is transferred from winding onto the first reel, to winding onto a second reel. The transfer stage may begin when the roll of sheet material around the first reel is approaching a predetermined size. The turret may be rotated in a forward direction to bring a second reel into a pre-transfer position. In the pre-transfer position, the second reel may initiate contact with the running web of the sheet material. As the pre- transfer position is configured, the cutter is preferably in the non-cutting position and the wrap roller is preferably in the inactive position. This may ensure that the cutter and/or the wrap roller do not obstruct rotation of the turret. Once the second reel is brought into the pre-transfer position, the cutter may then be moved into the cutting position and the wrap roller may be moved into the active position. The wrap roller may then deflect the path of the running web of the sheet material such that the sheet material is partially wrapped around the second reel and is partially wrapped around the wrap roller. In the pre-transfer position, the wrap roller and cutter may not yet be in an appropriate position relative to the second reel for the cutter to cut the sheet at the pre-determined point downstream of the second reel. In other words, the cutter may not yet be aligned to cut the sheet material at the pre-determined point downstream of the reel.

Rotation of the turret in the reverse direction may move the second reel into the transfer position, the extent of the reverse rotation being dependent on the diameter of the second reel. For example, a larger diameter reel may require more rotation than a smaller diameter reel. In the transfer positon, the web may be deflected to a greater extent than in the pre-transfer position. The web may be deflected so that it runs in the shape of an "S" around the wrap roller and the reel. For example, the wrap roller may be positioned relative to the reel to wrap the running web around at least 180°, and preferably more than 270° of the circumference of the reel. In the transfer position, the cutter and the wrap roller may be in the correct orientation relative to the reel for the cutter to cut the running web at the pre-determined point downstream of the reel, between the core and the wrap roller. So, in the transfer position, the cutter may be aligned with the in-running nip between the second reel and the wrap roller.

Immediately prior to cutting, part of the cutter, such as a head assembly, may extend to deflect the web into, or towards the in-running nip between the reel and the wrap roller. The web is preferably cut by a blade that advances at a speed at least matching (but preferably greater than) that of the running web. On cutting, the blade may insert the cut end of the web into the in-running nip between the reel and the wrap roller. Once the cutter has cut the sheet of material and the sheet begins winding around the second reel, the apparatus may revert to the winding stage on forward rotation of the turret. The roll of sheet material that was formed around the first reel can then be removed from the turret. Each of the plurality of reels (for example the first, second, third and fourth reels) may sequentially enter the transfer position.

The reel may comprise a driven shaft, and a core mounted on the shaft, such that the web of sheet material is windable around the core. The core may be manufactured from cardboard or plastics. The core may be removably mountable on the shaft. If there is a plurality of reels mounted on the turret, at any one time during operation, some of the reels may comprise cores whereas others may not. For example, when a roll has been completed, a core with the sheet material wrapped around it may be removed from the shaft. A new, empty core may be placed on the shaft prior to it entering the transfer position.

Some sheet products may be wound to form a roll with a predetermined inside diameter with no supporting core.

The invention may provide an apparatus for winding a sheet material. The apparatus may comprise a reel onto which a web of the sheet material is to be wound, a wrap roller which is movable relative to the reel to deflect a running web to run between the wrap roller and the reel and then around a portion of the circumference of the reel and a cutter for cutting the running web at a predetermined point downstream of the reel and inserting the cut end of the web between the reel and the wrap roller. The apparatus may also comprise a turret on which the reel is mounted; and a controller for variably rotating the turret, such that in use, the reel is movable to a transfer position in which the cutter is positioned, or aligned, to cut the running web at the pre-determined point downstream of the reel, between the reel and the wrap roller. The degree or amount of turret rotation required to effect, or configure, the second transfer position may thus be dependent on the diameter of the reel.

The controller is preferably a computer that is programmable to alter the extent of rotation required to configure the transfer position depending on the reel diameter. A user may thus be able to input the reel diameter on the computer, which, in turn, can control the rotation of the turret accordingly. The controller may be programmed, or programmable, to control variable rotation of the turret. The cutter is preferably mounted on a translating carriage, the translating carriage being controlled, in use, to move the cutter between a non-cutting position in which the cutter is not able to cut the running web and a cutting position in which the cutter is able to cut the running web. The wrap roller is preferably mounted on a translating carriage, the translating carriage being controlled, in use, to move the wrap roller between an inactive position in which the wrap roller is not able to engage the reel, and an active position in which the wrap roller is able to engage the reel. The movement of the cutter and the wrap roller may be controlled by a controller, such as a computerised controller.

In a preferred embodiment, the cutter and the wrap roller are mounted on the same translational carriage, such that, in use, movement of the cutter is coupled to movement of the wrap roller.

In a preferred embodiment, the apparatus comprises a first reel support arm (or a winding reel support arm) and a second reel support arm (or a transfer reel support arm). Each reel support arm is preferably rotatably mounted at the centre of the turret, or at the rotational axis of the turret, such that each reel is rotatable about the same axis as the turret. For example, each arm may be mounted on the drive shaft of the turret.

The reel support arms may releasably support or engage an end of each reel. This may ensure that, during winding, the sheet material is held securely in place and prevented from moving along the reel or coming off the reel, and/or it may secure the core. The reel support arms may only engage reels that are undergoing rotation, such as a reel around which the running sheet of the web material is being wound, or a reel to which the sheet material is being transferred. Consequently, if there is a plurality of reels, say four reels, the reels that are not engaged with the reel support arms may be accessible for offloading rolls of sheet material or for loading empty cores. The reel support arms may

sequentially engage each reel when progressing through the winding and transfer stages, as described above. An end of each arm may comprise a clamp for clamping to the end of each reel. The clamp may be opened and closed to disengage and engage the reels. The clamp may be opened and closed by a controllable driver, such as a pneumatic driver.

Each arm may be configurable between a locked, or engaged configuration, in which rotation of the arm is coupled to rotation of the turret, and an unlocked or disengaged configuration, in which the rotation of the arm is not coupled to the rotation of the turret, or in which the arm is able to rotate independently of, or relative to, the turret. For example, each arm may comprise a drive key that releasably engages the turret drive shaft. When the key is engaged with the turret drive shaft, rotation of the arm may be coupled, or fixed, to rotation of the turret, and rotation of the arm relative to the turret may not be possible. When the key is disengaged, rotation of the turret may be independent of the rotation of the arm, such that the arm may be rotatable relative to the turret. The first arm and second arm may be rotatable independently of one another, as long as rotation of at least one of the arms is not coupled to the rotation of the turret. The first and/or second arms may be rotatable in the first, forward direction and in the second, reverse direction.

The first arm and the second arm may engage, or be controlled to engage, a particular reel at different stages of the winding and transferring process. The first arm may engage a reel around which sheet material is being wound to form a roll. The second arm may engage a reel to which the running web of the sheet material is to be transferred. The second arm may thus engage an empty reel which may not yet have any of the sheet material wrapped around it. For example, with reference to the positions of the reel as described above, the second arm may engage the reel immediately prior to it entering the pre-transfer position, whilst it is in the pre-transfer position, and whilst it is in the transfer position. Once the running web of the sheet material has been transferred to the reel, the second arm may release the reel and the first arm may engage the reel. The first arm may thus not engage an empty reel, and may only engage a reel after the sheet material has been transferred to that reel. The first arm may engage the reel until a roll of sheet material has reached a pre-determined size, at which point it may then disengage the reel, allowing the roll of sheet material to be removed from the apparatus. Once the second arm has disengaged the reel it may engage a new, empty reel about to receive the running web of the sheet material. Once the first arm has disengaged the reel, it may move to a position where it can receive the new reel. So, a particular reel may engage the second arm prior to engaging the first arm. Each arm may sequentially engage each of the plurality of reels, in use.

For example, during the winding stage (described above), in which the running web of sheet material may be wound around a first reel to create a roll of the sheet material around the first reel, the first arm may engage the first reel and the second arm may engage the second reel. The second reel may be empty, but may be about to receive the sheet material. At this stage, the rotation of both the first and second arms may be coupled to the rotation of the turret. For example, both arms may be engaged with the drive shaft of the turret.

Rotation of the turret in the first, forward direction may thus result in an equivalent forward rotation of the first and second arms, and the second reel may be brought into the pre-transfer position. The cutter may then be moved into the cutting position and the wrap roller may be moved into the active position to deflect the path of the running web of the sheet material such that the sheet material is partially wrapped around the second reel and is partially wrapped around the wrap roller, as described above.

Whilst the first and second arms are still engaged with the drive shaft of the turret, rotation of the turret in the reverse direction may move the second reel into the transfer position, such that the cutter is aligned with the in-running nip between the second reel and the wrap roller. Once the running web of the sheet material has been cut by the cutter and the sheet material is being wound around the second reel, the first arm may disengage the first reel and may also disengage the drive shaft of the turret, such that the first arm can rotate independently of the turret. So, independently of the turret and of the second arm, the first arm may rotate, or be rotated, in the reverse direction, towards the second arm. There may now be an acute angle formed between the first arm and the second arm, the first arm being positioned between the first reel and the second reel. With the second arm still engaged with the drive shaft of the turret, and preferably with the cutter in a non-cutting position, the turret may rotate in a forward direction such that the second arm and the second reel move towards the first arm, to the point where the first arm and second arm are adjacent to each other and in contact with, positioned at, or aligned with the second reel. The first arm may, preferably simultaneously, engage the second reel whilst the second arm disengages the second reel. The second arm may disengage the drive shaft of the turret and rotate in the reverse direction, independently of the first arm and the turret, towards a third reel. The second arm may then engage the third reel, and the step-wise process may repeat.

Accordingly, the invention may provide an apparatus for winding a sheet material, comprising: a turret; a plurality of reels mounted on the turret; a first reel support arm and a second reel support arm, in which each arm is rotatably mounted at the rotational axis of the turret and is releasably engageable with an end of each reel, and in which each arm is controlled, in use, to sequentially engage each of the plurality of reels, and such that the second arm releasably engages a reel onto which the running web of the sheet material is to be transferred, and the first arm engages that reel once the running web of the sheet material has been transferred. The apparatus may comprise a controller for controlling each arm, in use. The invention may also provide a method for winding a sheet material, comprising sequentially and releasably engaging an end of each of a plurality of reels mounted on a turret with a first reel support arm and a second reel support arm, each arm rotatably mounted at the centre of the turret, in which the second arm releasably engages a reel onto which the running web of the sheet material is to be transferred, and the first arm engages that reel once the running web of the sheet material has been transferred.

SPECIFIC DESCRIPTION OF A PREFERRED EMBODIMENT

An embodiment of the invention will now be described, by way of example, and with reference to the accompanying drawings, in which:

Figure 1 shows an apparatus according to an embodiment of the invention in a first configuration;

Figure 2 shows the apparatus of figure 1 in a second configuration;

Figure 3 shows the apparatus of figure 1 in a third configuration;

Figure 4 shows the apparatus of figure 1 in a fourth configuration; Figure 5 shows the apparatus of figure 1 in a fifth configuration; Figure 6 shows the apparatus of figure 1 in a sixth configuration; Figure 7 shows the apparatus of figure 1 in a seventh configuration; Figure 8 shows the apparatus of figure 1 in an eighth configuration;

Figure 9 shows the apparatus of figure 1 in a ninth configuration; Figure 10 shows the apparatus of figure 1 in a tenth configuration; Figure 11 shows the apparatus of figure 1 in a eleventh configuration; Figure 12 shows the apparatus of figure 1 in a twelfth configuration; Figure 13 shows the apparatus of figure 1 in a thirteenth configuration; and Figure 14 shows the apparatus of figure 1 in a fourteenth configuration.

Figure 1 illustrates a winding apparatus 1 according to an embodiment of the invention. The winding apparatus receives an incoming web 2 of sheet material from a web processing machine such as a printer or rewinder. The apparatus has a turret, or wheel 3 on which are mounted four drivable shafts: a first shaft 17; a second shaft 19; a third shaft 21 ; and a fourth shaft 23. The four shafts are positioned at 90° intervals around the turret. The sheet is wound into a roll 25 around the first shaft.

A cutting apparatus 5 in the form of a cutter or cross-cut unit is mounted at one end of a translating carriage 7. The cutter is substantially as described in

EP1295831 A1. Key features of the cutter include a fixed pneumatic driver cylinder 27 from which a rod 29 carrying a head assembly 31 is extendable. The head assembly comprises a serrated cross-cut blade 37 which is positioned adjacent to a nose plate 39 on one side and miniature rollers 33 on its other side. In figure 1 , the rod is in a non-extended, or stand-by position and the blade is in a cocked configuration. The translating carriage 7 is movably attached to a rail or track 9 which is planar, the translating carriage being driven by a pneumatic driver (not shown). A pivoting arm or cam 13 is pivotally attached to another end of the translating carriage by pivot 12. A wrap roller 11 is mounted at the end of the pivoting arm and a pneumatic driver 15 is connected between the pivoting arm and the translating carriage.

Mounted on a drive shaft, or axis 63 of the turret 3 are two shaft or reel support arms: a first arm 51 and a second arm 57. An inner end of each arm is rotatably mounted on the drive shaft of the turret. A drive key at the inner end of each arm (not shown) is releasably engageable with the drive shaft of the turret. An outer end of each arm has clamp or jaw 55, 57 that can releasably clamp an end of each of the shafts 17, 19, 21 , 22. Pneumatic drivers on each arm 59, 61 are arranged to open and close the jaws. In use, the apparatus progresses through a sequence of stages or configurations as shown in figures 1 to 14.

In a first configuration, as shown in figure 1 , the apparatus is in a running or winding phase. Here, the running web of the sheet material 2 is being wound around a core (not shown) which is mounted on the first shaft 17. The sheet material is being wound to form a roll 25. The translating carriage 7 is retracted such that the cutter 5 is in a non-cutting position and such that the wrap roller 11 is in an inactive position. The running web of the sheet material is only in contact with the core on the first shaft. The second shaft 19, third shaft 21 and fourth shaft 23 are not in a position to engage or contact the sheet material.

The clamp 55 of the first arm 51 is clamped to an end of the first shaft 17, whilst the clamp 57 of the second arm 53 is clamped to an end of the second shaft 19. The first and second shafts are thus oriented at 90° to each other. As the first and second shafts rotate, the cores and the sheet material are secured to each shaft and cannot be removed. The first arm and the second arm are locked to the drive shaft 63 of the turret 3, because the drive key at the inner end of each arm is engaged, or locked, with the drive shaft of the turret.

In figure 2, the turret 3 has been rotated in a forward direction, to begin a transfer phase. The second shaft 19, on which is mounted an empty core (not shown), is positioned in a pre-transfer position. The running web of sheet material 2 runs around a portion of the outside of the empty core mounted on the second shaft, before adding to the roll 25 developing around the core on the first shaft 17. The translating carriage 7 remains retracted.

With the first and second arms 55, 57 locked to the drive shaft 63 of the turret, rotation of the drive shaft in the forward direction results in a corresponding rotation of the first and second arms. The first and second arms maintain their 90° orientation with respect to each other.

As shown in figure 3, the translating carriage 7 has been extended such that the cutter 5 is in a cutting position, and such that the wrap roller 1 1 is in an active position. The second shaft 19 remains in the pre-transfer position. Extension of the translating carriage along the track 9 brings the cutter and the wrap roller nearer to the second shaft. The wrap roller contacts the running web of the sheet material 2 and begins to deflect its path such that the sheet runs between the wrap roller and the empty core mounted on the second shaft.

As shown in figure 4, the turret 3 rotates in a reverse direction such that the second shaft 19 is moved into a transfer position. The degree to which the turret rotates to move the second shaft from the pre-transfer position to the transfer position is dependent on the diameter of the core placed on the second shaft and is controlled by a computer controller (not shown). A user may input the core diameter into the computer controller which controls the turret rotation

accordingly. For cores with a larger diameter, the degree of rotation will be higher. For cores with a smaller diameter, the degree of rotation will be lower. In the transfer position, the core is positioned such that the cutter is aligned to cut the sheet material 2. As the turret rotates backwards, the core on the second shaft exerts a force on the wrap roller 11. This causes the pivoting arm 13 to rotate about the pivot 12 connecting the pivoting arm to the translating carriage 7 and the pneumatic driver 15 is caused to retract. An increase in the rotation of the turret (resulting from an increase in core diameter) causes an increase in rotation about the pivoting arm. The result is that the wrap roller and the core are in contact, with the wrap roller positioned approximately between the core and the centre of the turret and the cutter is aligned with an in-running nip between the core and the wrap roller. The rod 29 of the cutter 5 is shown in a fully extended configuration in figure 5 in which the rod 29 carrying the head assembly has projected or extended towards the in-running nip between the second second shaft 19 and the wrap roller 11. The head assembly 31 picks up the running web 2 between the core and the wrap roller and deflects it towards the in-running nip between the wrap roller and the empty core. The head assembly urges the web against the empty core by means of one or more of the spring-loaded miniature rollers 33. Downstream from the miniature rollers, the web passes around the end of the small radius nose plate 39. At this point, the web is wrapped around a large portion of the circumference of the empty core, such as 300° or more of the circumference. As shown in figure 6, the blade 37 is then fired, driven by a coil spring mechanism (not shown) in the head assembly, such that it extends beyond the end of the nose plate to cut the web 2. The springs accelerate the blade rapidly to a speed comparable to that of the running web so that a cut end of the running web (not shown) is carried with the blade as it moves beyond the nose plate and is guided or forced by the blade into the in-running nip between the empty core and the wrap roller. The blade should not touch the wrap roller or the web on the reel, to avoid damaging them, but may come within as little as 1 mm of them. Figure 7 shows the apparatus once the cutter 5 has cut the running web of the sheet material 2. The head assembly 31 has retracted to the non-extended, or stand-by position. At this point, the web completely encircles the empty core on the second shaft 19 and so its cut end is drawn around the core, beneath the subsequent layers of the web being wound onto the core. The incoming web is no longer being wound around the first shaft 17.

As shown in figure 8, the pneumatic driver 59 of the first arm 51 opens the clamp 55. The clamp thus releases the end of the first shaft 17. In addition, the drive key of the first arm disengages the drive shaft 63 of the turret 3.

As shown in figure 9, with the clamp 55 of the first arm 51 released from the first shaft 17, and the drive key of the first arm disengaged from the drive shaft 63 of the turret 3, the first arm rotates relative to the turret and relative to the second arm 53, in a reverse direction. The second arm moves away from the first shaft 17. Consequently, the angle between the first arm and the second arm is reduced. The first arm may be said to be in a run position.

With the drive key of the second arm 53 still engaged with the drive shaft 63 of the turret 3, figure 10 shows that forward rotation of the turret moves the second arm and the second shaft 19 towards the first arm 51. Rotation continues until the configuration as shown in figure 11 is attained. Here, the first arm 51 and the second arm are positioned in a substantially parallel orientation adjacent to each other and both arms are aligned with, and positioned to engage, the second shaft. Also, the translating carriage 7 is retracted such that the cutter 27 is no longer in its non-cutting position, and such that the wrap roller 11 is no longer in its inactive position.

As shown in figure 12, the clamp 55 of the first arm 51 is closed to engage the second shaft 19, whilst, simultaneously, the clamp 57 of the second arm is opened to release to the second arm . The drive key of the second arm also disengages the drive shaft 63 of the turret 3, such that rotation of the second arm is no longer locked to rotation of the turret. Consequently, as shown in figure 13, the second arm rotates relative to the turret and the first arm, in a reverse direction. The second arm then aligns with the third shaft 21. Figure 14 shows the clamp 57 of the second arm after it has clamped the end of the third shaft.

Figure 1 shows a running or winding phase, and figures 2-14 show a transfer phase of the winding process. Once the transfer phase has been completed as described above, the roll 25 of sheet material 2 around the first shaft 17 can be removed, a new roll (not shown) can form around the second shaft 19, and a third shaft 21 is primed, ready to receive the sheet material when the next transfer phase is initiated.

Claims

1. A method for winding a sheet material, comprising:

deflecting the path of a running web of the sheet material to run between a wrap roller and a reel onto which the web is to be wound, and then around a portion of the circumference of the reel;

variably rotating a turret on which the reel is mounted, to position the reel at a transfer position where the cutter is aligned to cut the running web at a predetermined point downstream of the reel, the degree of turret rotation required to effect the transfer position being dependent on the diameter of the reel;

cutting the running web using the cutter at the pre-determined point downstream of the reel, between the reel and the wrap roller; and

inserting the cut end of the web between the reel and the wrap roller.

2. A method according to claim 1 , in which movement of the reel into the transfer position engages the wrap roller with the reel and exerts a force on the wrap roller.

3. A method according to claim 2, in which the wrap roller is mounted on a pivoting arm which rotates about its pivot on engagement with the reel, the extent to which the pivoting arm rotates about the pivot being dependent on the extent of the variable turret rotation.

4. A method according to any preceding claim, comprising moving the cutter between a non-cutting position in which the cutter is not able to cut the running web and a cutting position in which the cutter is able to cut the running web.

5. A method according to claim 4, in which the cutter is mounted on a translating carriage which moves the cutter between the non-cutting and the cutting positions.

6. A method according to any preceding claim comprising moving the wrap roller between an inactive position in which the wrap roller is not able to engage the reel, and an active position in which the wrap roller is able to engage the reel.

7. A method according to claim 6, in which the wrap roller is mounted on a translating carriage which moves the wrap roller between the inactive position and the active position.

8. A method according to claims 5 and 7 in which the cutter and the wrap roller are mounted on the same translational carriage, such that movement of the cutter is coupled to movement of the wrap roller.

9. A method according to any preceding claim in which the turret is rotated in a first, forward direction and in a second, reverse direction.

10. A method according to any preceding claim, in which the reel comprises a shaft, and a core mounted on the shaft, such that the web of sheet material is windable around the core.

1 1. A method according to any preceding claim, in which there is a plurality of reels mounted on the turret, and in which rotation of the turret permits each reel to be sequentially moved into the transfer position.

12. A method according to any preceding claim, in which there is a plurality of reels mounted on the turret; a first reel support arm; and a second reel support arm, each arm rotatably mounted at the rotational axis of the turret, and in which each arm releasably engages an end of each reel.

13. A method according to claim 12, in which the first arm releasably engages a reel around which the running web of the sheet material is wound to form a roll, and in which the second arm releasably engages a reel around which the running web of the sheet material is to be transferred.

14. A method according to claim 12 or claim 13, in which the second arm engages a particular reel prior to the second arm engaging that particular reel.

15. An apparatus for winding a sheet material, comprising:

a reel onto which a web of the sheet material is to be wound; a wrap roller which is movable relative to the reel to deflect a running web to run between the wrap roller and the reel and then around a portion of the circumference of the reel;

a cutter for cutting the running web at a pre-determined point downstream of the reel and inserting the cut end of the web between the reel and the wrap roller;

a turret on which the reel is mounted; and

a controller for variably rotating the turret, in use, to position the reel at a transfer position where the cutter is aligned to cut the running web at the pre- determined point downstream of the reel, between the reel and wrap roller,

in which the degree of turret rotation required to effect the transfer position is dependent on the diameter of the reel.

16. An apparatus according to claim 15, in which a plurality of reels is mounted on the turret.

17. An apparatus according to claim 15 or claim 16, in which there are at least three reels, preferably at least four reels.

18. An apparatus according to any of claims 15 to 17, in which the cutter is mounted on a translating carriage, the translating carriage being controlled, in use, to move the cutter between a non-cutting position in which the cutter is not able to cut the running web and a cutting position in which the cutter is able to cut the running web.

19. An apparatus according to any of claims 15 to 18 in which the wrap roller is mounted on a translating carriage, the translating carriage being controlled, in use, to move the wrap roller between an inactive position in which the wrap roller is not able to engage the reel, and an active position in which the wrap roller is able to engage the reel.

20. An apparatus according to claims 18 and 19 in which the cutter and the wrap roller are mounted on the same translational carriage, such that, in use, movement of the cutter is coupled to movement of the wrap roller.

21. An apparatus according to any of claims 15 to 20, in which the turret is controlled, in use, to rotate in a first, forward direction and in a second, backward direction.

22. An apparatus according to any of claims 15 to 21 , comprising a plurality of reels mounted on the turret; a first reel support arm; and a second reel support arm, each arm rotatably mounted at the rotational axis of the turret and releasably engageable with an end of each reel, in which each arm is controlled, in use, to sequentially engage each of the plurality of reels, and such that the second arm releasably engages a reel onto which the running web of the sheet material is to be transferred, and the first arm engages that reel once the running web of the sheet material has been transferred.

23. An apparatus according to claim 22, in which each arm is configurable between a locked state, in which rotation of the arm is coupled to rotation of the turret, and an unlocked state, in which the arm can rotate independently to the turret.

24. An apparatus for winding a sheet material, comprising:

a turret;

a plurality of reels mounted on the turret; and

a first reel support arm and a second reel support arm, in which each arm is rotatably mounted at the rotational axis of the turret and is releasably engageable with an end of each reel;

in which each arm is controlled, in use, to sequentially engage each of the plurality of reels, and such that the second arm releasably engages a reel onto which the running web of the sheet material is to be transferred, and the first arm engages that reel once the running web of the sheet material has been transferred.

25. An apparatus according to claim 24, in which the first arm and the second arm are each configurable between a locked state, in which rotation of the arm is coupled to rotation of the turret, and an unlocked state, in which the arm can rotate independently of the turret.

26. An apparatus according to claim 24 or claim 25, in which the first arm and the second arm each comprise a clamp for releasably engaging each of the reels.

27. A method for winding a sheet material, comprising sequentially and releasably engaging an end of each of a plurality of reels mounted on a turret with a first reel support arm and a second reel support arm, each arm rotatably mounted at the rotational axis of the turret, in which the second arm releasably engages a reel onto which the running web of the sheet material is to be transferred, and the first arm engages that reel once the running web of the sheet material has been transferred.

28. A method according to claim 27, comprising configuring a locked state in which rotation of the first and/or second arm is coupled to rotation of the turret and configuring an unlocked state, in which the rotation of the first and/or second arm is independent of the rotation of the turret.

29. A method substantially as hereinbefore described, with reference to the accompanying drawings.

30. An apparatus substantially as hereinbefore described, with reference to the accompanying drawings.