GB2314295A - Inflatable articles such as life jackets - Google Patents

Abstract

An inflatable article, in particular a life jacket, is constructed from an outer carcass 38, which is made from tough textile fabric sections secured together to form the jacket profile for fitting the user, and to provide the inflation, rather than making the carcass inflatable, which is difficult, a separate inflation balloon 32 is used inside the jacket. The balloon can be of a simple geometric shape such as a cylinder, and non-load bearing, but which will take up the appropriate shape of the jacket when inflated, which is a different shape compared to that which it would take up when inflated unrestrained.

Description

Improvements relating to inflatable articles such as life jackets This invention relates to inflatable articles such as life jackets, referred to hereinafter simply as life jackets As is well known, life jackets are used temporarily in emergency situations by passengers in vehicles such as boats and ships, and in aircraft, which travel on or over water. They are however used on a more permanent basis by personnel who work or participate in leisure activities adjacent bodies of water, and there is a risk that such personnel may have to survive being placed in such body of water for a prolonged period.

In any case, wearers of life jackets may have to drop, in emergency, considerable distances under gravity before reaching the water. It is recommended that in such cases, the life jacket should be deflated until the person hits the water, when the life jacket should be inflated, either automatically or by the user.

However, should it be that for whatever reason, the life jacket is inflated before the user hits the water, there is a surge of increased pressure (dictated by the height of the user's fall and the user's mass) in the life jacket which unfortunately can lead to bursting of the life jacket, in particular at one of the seams of the carcass of sheet material sections which are used to fabricate the life jacket.

Conventionally, life jackets designed to meet the requirement of resisting this bursting, which involves testing the life jacket at pressures up to 14.7 p.s.i., have been made using fabric sections to produce a life jacket carcass and these sections are made of tough textile material which are coated with a waterproofing composition, and the sections are secured together at the seams by overlapping the sections and by bonding/gluing the sections together where they overlap. Life jackets produced in this way are satisfactory as regards withstanding the pressure surges indicated above, but the method of production is expensive in that it is labour intensive.

Attempts have been made to use latest technology fabrics to produce life jackets by high frequency welding sections of the life jacket carcass arranged in face to face configuration, but seams formed in this way, although the method of seaming is less labour intensive and therefore less costly than the conventional method, have not been able to meet the pressure requirements as discussed above and the seams have failed in test. Accordingly, users of life jackets, especially the Royal Navy, have rejected the proposals, even though there are advantages of cost and other advantages in using the new fabric technology, and have continued to use conventionally produced life jackets.

The present invention aims to provide a new construction of life jacket which at least in preferred forms enables the use of new technology textiles, and yet provides a construction which enables the life jacket to withstand the pressures anticipated as discussed above.

According to the invention there is provided an inflatable life jacket wherein the fabric of the jacket enabling it to be inflated is double layered and comprises an inner layer of inflatable material and an outer layer of a material encasing the inner layer and of a construction to add to the strength of the fabric to enable it to withstand a high internal inflation pressure, and provide the correct shape of the inflated product.

The inner layer is preferably an inflatable tube or other body with a means, such as an oral inflation pipe, for the inflation of same and is separate from the outer layer, and in the fabrication of the jacket, the outer layer is preferably applied around the inner layer, preferably deflated or at least partly so.

In a particularly suitable arrangement, the inner layer is an unsupported, inflatable film of synthetic plastics material, such as polyurethane, which is capable readily of being heat sealed or welded and has connected thererto in a sealed manner the means for inflation of same.

In a specific embodiment, the inner layer preferably is of a simple geometric shape, whilst the outer layer may comprise a carcass in the final profile of the jacket. For example, it may be horseshoe shaped, with the ends connected, and it may be of varying width, for example wide at the front lower portion which in use lies in front of the user's chest, and narrow at the top rear portion which in use lies behind the user's head. With such an arrangement, the inner layer may comprise a simple, even width tube, which if inflated without restriction, would take up a long, constant cross section sausage shape. When it is in the outer carcass, however, it will still inflate, but will conform to the shape of the carcass.

The outer carcass is preferably comprised of tough textile cloth sections which can be sewn or otherwise secured together to form the carcass. These sections may or may not be coated with a substance which enables them to be sealed as well as sewn together at the seams. These seams will be of such strength to withstand the internal pressures of the level as discussed above, when the jacket is inflated to operational pressure, and the inflation tube need not withstand the stresses at the seals of the tube.

By this arrangement, the majority of the strength of the fabric of the jacket can be provided for in the outer layer and the inflation capability can be provided mainly in the inner layer. The combined layers enable the jacket to withstand the anticipated pressures without the usual drawbacks which exist in the prior art as discussed herein. Also, by providing that the inner layer is separate from the outer layer and in particular by using a tube which is a simple geometric shape, so that it can be produced easily and inexpensively, an advantageous product is produced both from a cost point of view and from a fabrication point of view.

It will be understood that the life jacket can be provided with auxiliary components such as the inflation pipe as mentioned herein, automatic inflation cylinders, a warning light, a whistle and so on.

Also the jacket may have another shape from that described herein and illustrated in the accompanying drawings, which show an embodiment of the invention and wherein; Fig. 1 is a sectional view showing how welded seams are jointed to join sections of the fabric of a life jacket together to form air tight seams; Fig. 2 is a sectional view showing how traditionally seams of a life jacket have been formed to produce life jackets which will withstand the pressures to make the life jackets suitable for use by the Royal Navy; Fig. 3 shows an inflatable tube which forms part of a life jacket according to the embodiment of the present invention; Fig. 4 shows an outer carcass of a life jacket according to the invention; and Fig. 5 is a view similar to Fig. 4 but showing the life jacket when provided with the inner tube and inflated.

Referring to the drawings, Figs. 1 and 2 are included to show how life jackets have been constructed in the past. The conventional construction is shown in Fig. 2 in which there is shown two sections 10 and 12 of tough textile material which have been rendered air impermeable by coating or the like with a suitable composition. The sections 10, 12 are secured together to form a seam 14 by being overlapped and, in this case, glued by a strong adhesive 16. The whole life jacket is made in this way so as to form an inflatable chamber, and the life jacket is provided with an inflation means, not shown. Jackets produced in this way are satisfactory as regard utility, but to produce them is labour intensive and therefore expensive.

New technology fabrics have been introduced which comprise textile material coated with a plastic coating such as polyurethane which have desirable properties making them suitable for life jackets. For example they can be welded face to face by a less labour intensive method than is needed for the conventional method described. In this connection, if reference is made to Fig. 1, which shows how a seam may be provided using new technology fabric for the connection together of two sections of a carcass of a life jacket, the sections 18, 20 are arranged so that edge regions 22, 24 are in contact face to face so that their coated sides 26, 28 touch. These edge regions can be fused or welded together easily by machinery to form the seam 30. Unfortunately, such seams are not sufficiently strong to withstand the pressures which will be experienced, as explained herein when the user has to jump from a substantial height, in the order of eighteen metres, into the water. Accordingly, despite the advantages to be gained from using the new technology fabrics, they have not been adopted by large users of life jackets, such as the Royal Navy.

The approach of the embodiment of the invention, as shown in Figs.

3, 4 and 5 is to construct the life jacket in two layers, which are not connected. The first layer is an inflatable tube 32 which is preferably of a simple geometric shape, so that it can be easily fabricated, and this is encased in and surrounded by a tough fabric carcass which need not provide any air impermeability, and of which the sections can be connected together by a very secure connection method, such as sewing, with or without welding as required.

The tube which is shown in Fig. 3 is a simple unsupported plastic film or membrane 34 which is of a rectangular shape and is folded in two and the meeting edges 36 are sealed together to form the inflatable tube 32. Other constructions are possible. For example two or more separate sections can be used to form the tube. The tube is furthermore provided with a means to enable the tube to be inflated, when required, as will be explained. The tube can be of any suitable material, but polyurethane is preferred.

The carcass 38 which is preferably applied over the tube 32 is shown in Fig. 4, and it comprises two horseshoe shaped sections 40, 42 which are seamed together at seams 44, 46, 48 to encase the tube 32, which by its flexible nature takes up the horseshoe shape. This shape is adopted to enable the user to locate his head in the aperture 50 which is created.

Although not shown, the means, such as an oral inflation pipe, for inflating the tube is accessible from the outside of the carcass 38, to enable the life jacket to be inflated.

In Fig. 4 the life jacket is not inflated, whereas in Fig. 5 it is. Fig. 5 shows that when the life jacket is inflated, using the inflation means provided on the tube, the inflatable tube takes up the horseshoe shape of the life jacket, which is one of the particularly preferred features of this invention. During inflation, in the initial stages the tube will inflate first, up to the inner surface of the carcass, and subsequently, the inflation pressure, up to the final pressure, will be taken by the stronger sewn carcass seams whose strength will dictate the maximum pressure which the life jacket can withstand. It is a simple matter to design these seams to withstand the in use anticipated pressures.

It can be seen from the invention that the new technology fabrics can be used in life jackets without suffering the disadvantages herein mentioned.

Claims (12)

Claims.

1. An inflatable article such as a life jacket comprising an inflatable fabric, wherein the fabric is double layered and comprises an inner layer of inflatable material and an outer layer of a material encasing the inner layer and of a construction to add to the strength of the fabric to enable it to withstand a high internal inflation pressure.

2. An article according to claim 1, wherein the inner layer is an inflatable tube or other body with a means, such as an oral inflation pipe, for the inflation of same and is separate from the outer layer.

3. An article according to claim 1 or 2, wherein, in the fabrication of the , the outer layer is applied around the inner layer, preferably when deflated or at least partly so.

4. An article according to any preceding claim, wherein the inner layer is an unsupported, inflatable film of synthetic plastics material, such as polyurethane, which is capable readily of being heat sealed or welded and has connected thereto in a sealed manner the means for inflation of same.

5. An article according to any preceding claim, wherein the inner layer is of a simple geometric shape, whilst the outer layer comprises a carcass of a different shape which defines in the final profile of the article.

6. An article according to claim 5, wherein the article is a life jacket, and the carcass is horseshoe shaped.

7. An article according to claim 6, wherein the ends of the carcass are connected.

8. An article according to claim 7, wherein the carcass is varying width, namely wide at the front lower portion which in use lies in front of the user's chest, and narrow at the top rear portion which in use lies behind the user's head.

9. An article according to claim 6, 7 or 8, wherein the inner layer comprises a simple, even width tube, which if inflated without restriction, would take up a long, constant cross section sausage shape.

10. An article according to any preceding claim wherein the outer layer comprises tough textile cloth sections sewn or otherwise secured together.

11. An article according to claim 10, wherein the sections are coated with a substance which enables them to be sealed as well as sewn together at the seams.

12. An article substantially as hereinbefore described with reference to the accompanying drawings.