The present invention concerns improvements in or relating to liners. More particularly, the present invention relates to liners which are utilised in articles of a moulded construction, such as footwear, particularly Wellington boots or gloves, as well as to loose liners for fitting in leather or other material boots and shoes or gloves. The invention also includes a method for producing such liners.

Wellington type boots are usually made by injection moulding processes in various types of plastics material or rubber compounds, the mould utilised generally comprises a last or internal plug mould and two or more external components which close over the last or internal plug mould to complete a cavity into which the plastics material or rubber compound is injected in order to form the Wellington boot.

In order to ensure that the finished product is user friendly, a fabric faced liner is placed over the last or plug mould, so that the fabric face is facing inward towards the last or plug mould and will appear on the internal face of the finished article.

The fabric liner utilised in such injection moulding processes has to be formed from a fabric having one surface which is sealed to withstand the moulding pressure from forcing the moulding compound through the liner and thereby appearing on the inside face of the finished article. Any article wherein the moulding compound had been forced through the liner would be rejected as unsuitable.

Fabric liners which are currently used in the above referenced moulding process are typically stitched together utilising slightly elasticated or stretch fabric. The liners are assembled from a kit of parts comprising, for example, a separate sole piece, two toe/side pieces and two heel/leg pieces. A flat type cover stitch is used to form the liner and assembly thereof can be difficult. Once the liner has been so formed, all the stitched seams then have to be sealed using a suitable sealant compound, in order to prevent moulding compound passing through the liner.

Such liners have to be made in left and right pairs and have to be an exact foot size in order to fit the last or internal mould without any wrinkles or distortions therein which would show up on the finished product. Thus, using current techniques, a user of such liners would have to have a plurality of containers for locating left foot and right foot pairs in a plurality of foot sizes.

It is an object of the present invention to provide a liner which at le ^' ast minimises the problems referred to above, whereby the liner of the invention will not permit passage of moulding compound therethrough, and will preferably enable the liner to "breathe". Moreover, the liner of the present invention is suitable for .both right foot and left foot without modification and is also stretchable to be suitable for use for a plurality of foot sizes.

In accordance with an aspect of the present invention there is provided a liner for lining the interior of an article, particularly a Wellington boot, said liner being formed from one or more sheets of fabric material having a covering on one side thereof.

said covering being impermeable or vapour permeable, and the edges of said shee (s) being joined together in a sealed manner.

In accordance with another aspect of the present invention, there is provided a liner for lining the interior of an article, particularly a Wellington boot, comprising a substantially flat member, said member being formed of a sheet of fabric material having a covering on one side thereof, said covering being impermeable or vapour permeable, said liner being formed from one or more pieces of said fabric covered material which are so shaped that, when the edges thereof are joined together in a sealed manner, the member has a sock shape-like appearance.

The liner may be formed from fabric material having a covering on one side thereof, said covering suitably being in the form of a coating, film or laminate of impermeable or vapour permeable material. For example, the liner may be in the form of nylon coated with polyurethane, or in the form of a polyurethane film having a floe coating, or in the form of a laminate comprising a polyester fleeced layer, a foam layer and a layer of polyurethane film.

The fabric material, suitably nylon, from which the liner is produced preferably has a high degree of two way stretch and a fabric face which is user friendly.

In a further aspect of the invention there is provided a method of producing a liner for lining the interior of an article, comprising joining together the edges of one or more sheets of fabric material having a covering on one side thereof, said covering

being "impermeable or vapour permeable, said edges being joined together by joining means in a sealed manner.

The edges of the piece(s) of the fabric covered material may be joined together by any appropriate joining means to produce the required seal. Whilst it is possible to utilise a cover stitch or the like with subsequent application of sealant or taping, the covering of the present invention is designed to be suitable for radio frequency welding assembly of the liner or for thermal fusing or ultrasonic welding.

The _. impermeable or vapour permeable covering is suitably formed from polyurethane or other suitable compounds.

In a preferred embodiment of the present invention, the liner is comprised of two pieces of fabric, a left side and a right side of suitable shape so that when the edges are joined together, suitably by welding, the liner is formed in a shape similar to that of a sock. In such arrangement, a knife edge type tool is suitably used, said tool being in the shape of a sock or having a shape similar to a sock. Such tool is utilised to weld a narrow weld track beneath and on either side of the tool contact point. After the welding process is completed the tool is pressed further by high pressure means, to cut through the welded track. A liner is thereby formed having a very fine welded seam with a closely trimmed edge. This produces a strong but almost undetectable seam in the finished product.

It is also possible to form the liner from a single piece of fabric which would be cut to the

required shape and then folded over and the edges joined together in a sealed manner.

As mentioned above, during the welding process, the edges are preferably trimmed such that the welded seam is very fine and does not form an objectionable ridge inside the finished article.

Also in accordance with the present invention there is provided a method of producing a Wellington boot incorporating a liner of the invention, in which the liner of the appropriate general boot size is pulled over a last located in the interior of an injection moulding apparatus, the fabric face of the liner facing inwards towards the last, the external components of the mould then being closed, suitable moulding compounds are then injected into the cavity within the mould and the Wellington boot is formed around the liner, the mould thereafter being opened and the Wellington boot and liner removed therefrom.

An added advantage of the present invention, utilising a water vapour permeable covering, is that when such liner is used with injection moulding compounds that also have a vapour permeable quality, then, in the case of production of Wellington boots, the"Wellington boot and liner are vapour permeable in total. Such type of Wellington boot would have particular application on oil rigs and in hospitals, etc.

It can thus be seen that the liner in accordance with the present invention will fit universally on either a left or right foot last without distortion, and the shape and degree of stretch in the fabric material utilised ensures that the liner will

fit at least three shoe or boot sizes. This, will of course, achieve a tremendous saving in the number of different types of liner required.

The present invention will be further illustrated, by way of example, with reference to the accompanying drawing which schematically shows a liner in accordance with the present invention, part of the leg portion being cut-away.

The liner 10 illustrated has been formed from two pieces of fabric material 11,12 having a covering 13 on one side thereof, said covering being either impermeable or vapour permeable. The two pieces comprise a left side and a right side of such a shape that, when the edges 14,15 are welded together it forms the general shape of a sock. The edges 14,15 are preferably welded together in a sealed manner utilising a knife edge type tool in the shape of a sock. Such tool welds a narrow weld track beneath the tool contact point, and on either side of *the material. After the welding process is completed the tool is pressed further by a high pressure means to cut through the welded track and from the liner 10 with a very fine welded seam having a closely trimmed edge.

The liner is generally flat and since the fabric from which it is formed has a high degree of two way stretch, it is possible to adapt the liner to any particular shape of last.

The fabric material is preferably nylon coated with polyurethane. However, it is also possible to utilise a polyurethane film having a floe coating or a laminate comprising a polyester fleeced layer, a foam layer and a layer of polyurethane film.

Ih the manufacture of a Wellington boot, a liner of the present invention, of the appropriate general foot or boot size, would be pulled over a last located in the interior of an injection moulding apparatus. When placing over the internal last, it is to be ensured that the fabric face is facing inwards towards the last so that same will appear on the internal face of the finished Wellington boot.

Since the liner has a high degree of stretch, the liner can be pulled around the last so as to conform to the exact shape thereof. Once in position, the external components of the mould are closed thereover. Thereafter, suitable moulding compounds are injected into the cavity within the mould and the Wellington boot is formed around the liner. In the case where the liner is vapour permeable, such moulding compounds preferably have a vapour permeable quality so that, when withdrawn from the mould, the boot and liner are totally vapour permeable.

The preferred welding of the edges of the liner together as described above ensures that a particularly strong join is obtained, such join being unaffected by the liner being stretched so as to conform to the exterior shape of the last when located thereover.

It can thus be seen that the liner of the present invention has many advantages over previously utilised liners, particularly that the liner of the invention is utilisable for either foot and being applicable to a plurality of foot sizes, as well as the need for a separate sole piece being no longer necessary. Such advantages are achieved by utilising fabric which has a high degree of two way stretch.

Preferably, the provision of a covering which is water vapour permeable enables the liner to be utilised with a Wellington boot which is formed from water vapour permeable material, thereby ensuring that the total Wellington boot and liner are vapour permeable.

It is also believed that the liner of the present invention is more economic to manufacture than previously utilised liners.

The liner of the present invention can be extended to form part of another garment, such as thigh length waders or chest waders, or part of a fully watertight or semi-watertight suit. In addition, the liner of the invention can be used to fit gloves manufactured in the manner described above for the polyurethane injection moulded Wellington boots. Also, the liners of the invention can be used as loose liners to fit in leather or other material boots and shoes, or gloves.