WO2004048193A1

WO2004048193A1 - Novel inflation system for inflatable life jackets

Info

Publication number: WO2004048193A1
Application number: PCT/SE2003/001611
Authority: WO
Inventors: Stefan Glasa
Original assignee: P & P Utveckling AB
Current assignee: P & P Utveckling AB
Priority date: 2002-10-17
Filing date: 2003-10-16
Publication date: 2004-06-10
Anticipated expiration: 2005-04-17
Also published as: AU2003272167A1; DE20215944U1; EP1551699A1

Abstract

A novel inflation system for inflatable life jackets, comprising a gas reservoir of transparent plastic which stores liquid gas at a low pressure and which is connected to a casing which is transparent in full or in part and in which the opening mechanism for the gas reservoir is integrated and which has a profile for being attached to a receiving part connected to the inflatable life jacket and having an opening to the inner space of the life jacket, thus inflating the life jacket to the usage size by means of the spontaneous volume expansion for the liquid gas through both openings when the gas flows through a large outlet opening in the casing part, characterized in that the gas reservoir is surrounded by a casing such that the outer surface of said gas reservoir tightly abuts the inner surface of the casing.

Description

Novel inflation system for inflatable life jackets

The invention relates to a novel inflation system for inflatable life jackets, comprising a gas reservoir of transparent plastic which stores liquid gas at a low pressure and which is surrounded by a casing which is transparent in full or in part and in which the opening mechanism for the gas reservoir is integrated and which has a profile for being attached to a receiving part connected to the inflatable life jacket and having an opening to the inner space of the life jacket, thus inflating the life jacket to the usage size by means of the spontaneous volume expansion of the liquid gas through both openings when the gas flows through a large outlet opening in the casing part.

Inflation systems for life jackets which use carbon dioxide gas for inflation are known. This gas is inexpensive and basically harmless to humans. It is disadvantageous that the storage of gas of these systems is only possible in the high pressure range of up to approximately 150 bar at 45° C in the form of relatively heavy steel bottles. These bottles are configured in a cartridge-like manner and are welded closed following filling with gas since considerably higher gas pressures occur at a high storage temperature, e.g. at 70° C. In life jackets, the weight of these cartridges is three to five times heavier than the actual gas filling. These cartridges are opened by means of an additional opening mechanism in which a needle-like steel point pierces the welded closure lid of the metal cartridge. Even though only a small opening is attained, a force of approximately 300 N is necessary. The opening mechanisms are therefore correspondingly large and heavy. A further major disadvantage is that the CO₂ gas has a small molecular structure and can diffuse over time through the so-called gas-tight material of the inflated life jacket used. This can lead to major problems if the person to be rescued is unconscious for a long period of time in water which is not too cold. It is furthermore not possible to see whether there is actually any gas in the cartridge. It may therefore occur that owing to a simple mistake, a cartridge which has already been used or a cartridge which has emptied of its own accord owing, for example to rust formation, is assigned to the automatic inflation system. The small opening cross-section of the cartridge opening at low operating temperatures represents a further disadvantage. Icing occurs during use owing to the high pressure difference to the cartridge and the chambers of the automatic opening system, which considerably delays the filling time of the life jacket.

The object of this invention is to eliminate the disadvantages described above and to create a secure and very cost-effective inflation system which is also simple in terms of use and function. The development of new propellant gases, which are just as harmless for humans and the environment as conventional gases (e.g. CO₂), results in a completely new system solution for the present invention as compared to known systems. This is due, in part, to the fact that a system which uses gas in the low-pressure range results in much more favorable static requirements for all the components of an automatic inflation system, correspondingly enabling simple and cost-effective manufacture. The inlet openings can be much larger so that inflation of the life jacket is fully functional even at extremely low temperatures. By using a liquid gas in the low-pressure range as the filling, the opening mechanism, be it manual or automatic - i.e. water-activated systems in the case of so-called faint-proof life jackets - is directly integrated in the casing of the gas reservoir. This means that there is no need for a separate opening mechanism. The invention is therefore also to be seen as a so-called single use automatic inflation system. The gas reservoir and the casing are made of a transparent material and allow the fill level of the liquid gas in the reservoir to be seen with the naked eye.

Further advantages of the invention are revealed by the following description and embodiments.

Fig. 1 shows the floating body (1) of a life jacket including the novel inflation system (2, 3) and a manually operated opening cord having a grip ring (4). In most cases, the jackets are also equipped with an oral inflation device (5), however, this is irrelevant in this case. The full section (fig. 5) and the half-section C-C (fig. 6) clearly show the configuration of the embodiment. The actual gas reservoir consists of a relatively thin- walled, bottle-like part of transparent plastic, which has very low diffusion properties as regards the liquid gas used. Since storage times that are as long as possible are targeted, the gas reservoir can be lined, on the inside or the outside or on both sides, with a very thin, glass-like layer as a diffusion barrier. This may occur by way of what is called plasma coating according to prior art. Manufacturing the gas reservoir as a so-called blow-molded article is particularly economical. Since the low-pressure gas used also creates a vapor pressure of approximately 15 bar at approximately 70° C, the gas reservoir is almost entirely tightly surrounded by the likewise transparent casing parts in order to prevent the gas reservoir from bursting. Thus, the structure is such that the inner gas reservoir predominantly guarantees the chemical inertness and diffusion and in that the surrounding casing prevents the gas reservoir from expanding unintentionally or even bursting by means of wall thicknesses that are accordingly statically designed. This constitutes an essential advantage of the invention since it would be impossible and also much too complicated with the used liquid gas according to prior art to consider manufacturing the casing and the gas reservoir almost in one piece - such as, for instance, a transparent single use cigarette lighter. While plastics are being researched which also promise good diffusion properties, processing as an injection-molded article for the present use would not be economical since the processing parameters must be very strictly observed and would only be conceivable with a very high quality monitoring effort. The material would moreover entail unsolvable contradictions in the application technology. The container would, for example, be very brittle and thus extremely easy to damage, for instance in the case of an inadvertent fall from a low height, if it has good diffusion properties.

The full section (fig. 6) clearly shows that the gas reservoir (1) is surrounded by two casing parts (3, 4). The mouth piece of the gas reservoir (1) with the closure plug (5) protrudes into a kind of antechamber having an outlet opening (6) so that the gas can flow out through the outlet opening when the closure tappet is pulled out. Simple rubber seals (8, 9) seal the antechamber from the outside.

In order that the reservoir is not opened too easily or unintentionally, a small shearing pin (7) is provided which enables a defined minimum opening force.

Figs. 2, 4 show a sketch of the configuration of the gas reservoir including the enclosing casing. The locking profile (4), which enables a solid and safe, yet releasable locking, the outlet opening (2) and a flat rubber seal can be seen herein.

The receiving part (5) can be seen in fig. 3, which is connected to the gas chamber to be inflated of the life jacket (6). It can be seen that said part (figs. 2, 4) can be easily locked in the receptacle (5) such that the openings (2, 7) become congruent so that the gas may flow into the life jacket when the gas reservoir is opened.

Claims

1. A novel inflation system for inflatable life jackets, comprising a gas reservoir of transparent plastic which stores liquid gas at a low pressure and which is connected to a casing which is transparent in full or in part and in which the opening mechanism for the gas reservoir is integrated and which has a profile for being attached to a receiving part connected to the inflatable life jacket and having an opening to the inner space of the life jacket, thus inflating the life jacket to the usage size by means of the spontaneous volume expansion of the liquid gas through both openings when the gas flows through a large outlet opening in the casing part, characterized in that the gas reservoir is surrounded by a casing such that the outer surface of said gas reservoir tightly abuts the inner surface of the casing.

2. A novel inflation system for inflatable life jackets according to claim 1 , characterized in that the walls of the gas reservoir are additionally provided with a very thin, glass-like layer.

3. A novel inflation system for inflatable life jackets according to claim 1 , characterized in that several gas reservoirs are assigned to the casing part in the case of large gas volumes.