FIELD OF THE INVENTION The present invention relates to an apparatus for conveying fibres through offset first and second web needling zones of a needle loom to form a non-woven web and an assembly including such an apparatus and a needle loom.

BACKGROUND OF THE INVENTION

It has been previously proposed to use parallel wires to carry loose fibres through a needle loom for punching. Within the loom, needles are used to punch the fibres and join them together at locations beside each wire, resulting in a striped appearance. Also, in previous examples, the parallel wires are formed by a long continuous wire that extends around a plurality of rotating parallel shafts in a manner whereby each time the wire passes around a shaft it becomes offset a small amount so that adjacent portions of the wire are offset and in parallel to transport the fibres to the needle loom. Although a long continuous wire allows easy speed synchronisation, it is prone to stretching and time consuming to replace. Examples of the invention seek to solve, or at least ameliorate, one or more disadvantages of previous apparatus for conveying fibres through a needle loom.

SUMMARY OF THE INVENTION According to one aspect of the present invention, there is provided an apparatus for conveying fibres through offset first and second web needling zones of a needle loom to form a non-woven web, comprising:

a plurality of parallel endless conveying lines upon which the fibres are conveyed, each line extending from an entry section, through the loom, through an exit section and returning to the entry section, wherein each line passes via an offsetting device disposed intermediate of the first and second needling zones and configured to laterally offset each line between the entry section and the exit section, whereby the web is partially formed in the first needling zone by engaging a portion of the fibres and the remaining fibres are engaged in the second needling zone to form the remaining portion of the web. According to preferred embodiments, the offsetting device includes a pair of rollers adjacent the and a lower roller, the upper rollers being disposed so as to provide a generally horizontal conveying surface.

Preferably, at least one of the rollers of the offsetting device includes a slot for guiding an offset winding.

Preferably, a plurality of web sections are formed in the first and second needling zones, each web section being in the range of approximately 30mm wide to approximately 40mm wide.

Preferably, each line passes around the offsetting device. According to preferred embodiments, each line is a wire or strimmer wire.

According to one aspect of the present invention, there is provided an assembly including an apparatus according to any one of the preceding claims and a needle loom, the needle loom having first and second needling zones which are laterally offset from each other so that a portion of fibres entering the loom are formed in the first needling zone and the remaining fibres are formed in the second needling zone. BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will be further described, by way of non-limiting example only, with reference to the accompanying drawings in which:

Figure 1 is a schematic sectional view of an apparatus of one embodiment of the invention;

Figure 2 is an end view of the apparatus; Figure 3 is a close schematic sectional view of the apparatus;

Figure 4 is a close schematic sectional view of a transfer device of the apparatus; Figure 5 is a close schematic end view of a transfer device of the apparatus;

Figure 6 is a close schematic plan view of a transfer device of the apparatus;

Figure 7 is a schematic plan view of a formed web;

Figure 8 is a close end view of a roller of the transfer device; and

Figure 9 is a schematic plan view of first and second web needling zones of a needle loom. DETAILED DESCRIPTION

With reference to Figure 1, there is shown an apparatus 10. The apparatus 10 is configured for conveying fibres through offset first and second web needling zones 12, 14 respectively of a needle loom 16 to form a non-woven web (not shown).

The apparatus 10 comprises a plurality of parallel endless conveying lines 20 upon which the fibres are conveyed 20, as best seen in Figure 2. As illustrated, upper and lower lines are provided and symmetrically arranged on opposite sides of the web. A lower line 20 passes over bed plate 22 and an upper line 20 passes over a stripper plate 22. Between the lines 20, bunches of loose fibres are conveyed to a needle loom 16, through the loom 16 and from the loom 16 to form a non-woven web. In the needle loom 16, the fibres are punched with felting needles to form the web. In other forms, the fibres may be bonded together with heat to form the web. Each line 20 extends through a loop from an entry section 24, through the loom 16, through an exit section 26 and then returns to the entry section 24. Each line 20 passes via a offsetting device 30 disposed intermediate of the first and second needling zones 12, 14. In some forms, each line 20 passes via the offsetting device so as to be deflected, using a guide for example, though in other forms each line 20 passes around the offsetting device 30. The offsetting device 30 is configured to laterally offset each line 20 between the entry section 12 and the exit section 14 so that the web is partially formed in the first needling zone 12 by engaging a portion of the fibres and the remaining fibres are engaged in the second needling zone 14 to form the remaining portion of the web.

In the first needling zone 12, a plurality of continuous elongate sections of the web are formed, with each section being separated by an unformed section of fibres, which are to be engaged so as to be formed in the second needling zone 14, as illustrated schematically in the plan view of Figure 7 which shows the web being progressively formed as it moves through the loom 16 and toward the exit section 26. Although the first needling zone 12 and second needling zone 14 are shown as being side by side, there may be some overlap between the sections.

Figure 9 schematically illustrates, in plan view, the offset between the first needling zone 12 and second needling zone 14 that results in a plurality of web sections being formed in the first and second needling zones. In each of the needling zones, there is provided a plurality of spaced apart needling elements 32, which may include a plurality of needles, heating elements, or other devices for needling the web. Voids 34 are disposed between the needling elements 32 and, in use, result in an unformed web section being disposed between sections formed in the first needling zone 12. The needling elements 32 of the first needling zone 12 are offset from those of the second needling zone 14 so that portions of fibres not engaged in the first needling zone 12 are engaged in the second needling zone 12 to form a web being continuous across its width and length. In preferred embodiments, the voids are in the range of approximately 30mm to approximately 40mm.

Returning to Figures 3 and 4, it can be seen that the upper offsetting device 30 includes a pair of rollers 40, 44 disposed near the stripper plate 22 and a third roller 42 spaced from the stripper plate 22. The lower offsetting device 30 also includes a pair of rollers disposed near the bed plate 18 and a third roller spaced from the bed plate 18. The rollers 40, 44 are preferably disposed close to the stripper plate 22 so as to provide a generally horizontal conveying surface. In some forms, guides (not shown) may be provided in the stripper plate 22 and bed plate 18 to guide the line 20 toward the offsetting device 30.

As can be seen in Figures 5 and 6, as each line passes over the offsetting device, it is laterally translated, displaced or moved a small amount to one side. This allows a portion of the web not formed in the first zone 12 due to the needling elements 32 being spaced from the line 20 to avoid interference, to be formed in the second zone 14. The line 20 is offset by passing through slots formed in the rollers, such as slot 50 illustrated in Figure 8. It will be appreciated that slot 50 is preferably slightly larger than line 20 while maintaining a close fit. In one example, the line 20 has a 1.0 mm radius and the slot has a 1.2 mm radius.

It will be appreciated that line 20 may take many forms, either metallic or polymer. In some forms it may be a wire, rope or other form of cord or polymer strand, though in a preferred form it will be a commonly available strimmer wire.

The above described apparatus may be supplied as an apparatus for use with a needle loom, or it may be supplied as an apparatus of the above described type and including a needle loom 16, the needle loom 16 having first and second needling zones 12, 14 which are laterally offset from each other so that a portion of fibres entering the loom 16 are formed in the first needling zone 12 and the remaining fibres are formed in the second needling zone 14.

The apparatus 10 may be provided with needling elements 32 configured for completely needling a non-woven web, or it may be configured for only pre-tacking the fibres for later needling into a non-woven web using a second process, such as passing through a heating oven.

The embodiments have been described by way of example only and modifications are possible within the scope of the invention disclosed.