ANTI-STATIC CORE FOR

RECEIVING WOUND SHEET MATERIAL

This invention relates to a core for receiving wound sheet material and, more especially, this invention relates to a core which is for receiving wound sheet material and which has an anti-static capability.

In industry, sheet material is wound on cores to form reels. The sheet material may be, for example, paper, plastics film or cardboard. During use of the reels, the unwinding of the sheet material from its core often causes a build up of static electricity. The static electricity is caused by the fact that the cores are usually made of a non-conductive material, for example cardboard or a plastics material. The build up of the static electricity is due to a Van de Graff effect and high levels of the static electricity, which vary in dependence upon reel rotational speed and humidity levels. The problem of the static electricity is notorious in the printing industry. Static electricity discharges can harm personnel working in the vicinity and/or cause fires on process machines. Antistatic devices are known which deal with the above problem.

It is an aim of the present invention to provide an improved solution to the problem caused by the static electricity.

Accordingly, in one non-limiting embodiment of the present invention there is provided a core for receiving wound sheet material, which core comprises a tube, a first end member inserted in a first end of the tube, and a second end member inserted in a second end of the tube, the core being

such that it is able to be earthed in order to enable the discharge of static electricity from the core, and the earthing being such that it is effected by a chuck of a machine handling the core during use of the core whereby the static electricity is discharged through the machine.

The core of the present invention is advantageous in that, during use of the core, the chuck will always be in the core. Thus, as the static electricity is generated during the unwinding of the sheet material, the static electricity can substantially immediately be discharged through the chuck and the machine containing the chuck.

The core may be one in which the earthing is effected by a separately formed earthing means.

With a separately formed earthing means, the core may be one in which the earthing means extends along a part of an inner surface of the tube and along a part of an inner surface of one of the end members.

The earthing means may be separately fitted to one of the end members. Thus, for example, the earthing means may extend through a hole in the end member. The earthing means may alternatively be moulded in one of the end members.

The earthing means may be an electrically conducting strip. Other electrically conducting shapes may be employed. Any suitable and appropriate electrical conducting material may be used, for example copper.

Instead of having the earthing effected by a separately formed earthing means, the core may alternatively be one in which the earthing is effected by at least one of the end members being made of an electrically conducting

material. Any suitable and appropriate electrically conducting material may be employed.

In all embodiments of the invention, the core is preferably such that it is able to earthed by the chuck handling the core at either end of the core. In this case, the first and the second end members will usually have the same static electricity discharging construction. If desired the first and the second members could have a different static electricity discharging construction, but they would still both be able to discharge the static electricity. Alternatively, if desired, the core could be such that the discharge of the static electricity is able to be effected from one end only of the core, and in this case the core will normally be one in which only one of the end members has the static electricity discharging construction.

The core may be made of any suitable and appropriate materials. The core is preferably made of aluminium. Examples of other materials are cardboard and plastics materials. The core may be made in any suitable and appropriate sizes so that, for example, the core may be 3 - 14 inches (75 - 356 mm) in diameter.

The end members may be made of any suitable and appropriate material. Preferably, the end members are made of a plastics material. The plastics material may typically be polypropylene. The end members may be disposable end members or re-usable end members.

The core may include a radio frequency identification tag. The radio frequency identification tag will be protected from the effects of the static

electricity because the static electricity will be able to be discharged simply and substantially immediately on generation.

The present invention also extends to the core when including the wound sheet material. As indicated above, the wound sheet material may be paper, plastics film or cardboard. Other sheet materials may be employed.

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

Figure 1 is a section through part of a core for receiving wound sheet material, the core being handled by a chuck of a machine;

Figure 2 is a cross sectional view like Figure 1 but without the chuck;

Figure 3 is a side view of the core shown in Figure 1 ;

Figure 4 is an exploded view of the core shown in Figure 3 but without the earthing means shown in Figures 1 and 2;

Figure 5 is an end view of one of the end members as shown in Figure

4;

Figure 6 is a perspective view of a tube part of the core as shown in Figure 4; and

Figure 7 shows the core of Figures 1 - 6 provided with wound sheet material and being used in industry.

Referring to Figures 1 - 6, there is shown a core 2 for receiving wound sheet material. The core 2 comprises a tube 4, a first end member 6 inserted in a first end 8 of the tube 4, and a second end member 10 inserted in a second end 12 of the tube 4. The core 2 is such that it is able to be earthed in order to enable the discharge of static electricity from the core 2. The

earthing is such that it is effected by a chuck 14 of a machine handling the core 2 during use of the core 2 whereby the static electricity is discharged through the machine.

The core 2 is such that the earthing is effected by a separately formed earthing means 16. The earthing means 16 extends along a part 18 of an inner surface 20 of the tube 4, and along a part 22 of an inner surface 24 of the first end member 6. The earthing means 16 is separately fitted to the first end member 6 by passing through a hole (not shown) in the first end member 6. In an alternative construction, the earthing means 16 may be moulded in the first end member 6 during the formation by moulding of the first end member 6. The earthing means 16 is in the form of an electrically conducting strip which conducts the static electricity to the chuck 14 of the machine handling the core 2.

Referring to Figures 3 and 4, the second end member 10 is constructed the same as the first end member 6. Thus the second end member 10 also has the earthing means 16. The first and the second end members 6, 10 respectively are thus of the same static electricity discharging construction. The core 2 is then such that it is able to be earthed by the chuck 14 handling the core 2 at either end of the core 2.

The tube 4 is made of aluminum but other materials may be employed. The first and the second end members 6, 10 are made of polypropylene but other plastics materials may be employed.

Referring now to Figure 7, there is shown the core 2 provided with a roll of sheet material 26 in order to form a reel 28. The sheet material 26 is

shown being removed from the core 2 for processing. The sheet material 26 is shown passing over a steel path roller 30, whereafter static electricity can build up on the sheet material 26 in the area indicated generally by arrow 32. Without the use of the earthing means 16, static electricity could then be discharged onto a machine such for example as a printing machine as indicated by arrow 34. With the earthing means 16, the static electricity is able to be discharged via the chuck and the handling machine handling the core 2. The chuck is always in contact with the core 2 and thus the static electricity is able to be discharged without sparks as would occur as indicated by the arrow 34 if the earthing means 16 were not present. The avoidance of the sparks avoids the possibility of the sparks causing fires. The discharge of the static electricity via the chuck 14 and its associated handling machine also avoids personnel working in the vicinity of the sheet material 26 receiving unpleasant and possibly harmful static electricity shocks.

It is to be appreciated that the embodiment of the invention described above with reference to the accompanying drawings has been given by way of example only and that modifications may be effected. Thus, for example, the tube 4 and the first and the second end members 6, 10 may be of different constructions to those shown. The core 2 shown in Figure 7 is typically shown as being used in a printing works but it could also be used in other areas of industry. If desired, one of the end members may be provided with a radio frequency identification tag for enabling the position of the core 2 to be tracked from manufacture to end use. The end members employed in

the core 2 may be disposable end members or they may be re-usable end members.