GB2507292A - An immersion sensitive automatic floatation device - Google Patents

Abstract

A flotation device (1, Fig 1) attachable to articles such as keys, wallets and mobile telephones, which can prevent loss of such articles if they are dropped into a body of water by floating them back to the surface. The device comprises a container of compressed gas 20, an inflatable bag 30 and a trigger means 40. The trigger means is associated with the container, may comprise a spring (41, Fig 3) which may be retained under tension within a water reactive band (42, Fig 3), and is operable on immersion of the device in water to open the container 20 and allow gas from the container to inflate the bag and stop the articles from sinking. The flotation device may comprise an outer casing made up of a base section 11 and an upper section (12, Fig 1). The base section is further provided with an attachment means 13. The device further comprise hinged sections (16, 17, Fig 3) adapted to hinge outwards upon immersion in water and further impede the sink rate by increasing drag.

Description

Floatation Device The present invention relates to a floatation device. In particular, the present invention relates to a device which is attachable to other articles, such as keys, wallets and mobile telephones, but not limited thereto, and which incorporates an automatically inflatable bag which will serve as a float for such articles if they are dropped into water, accidentally or otherwise. In this way retrieval of such articles is facilitated.

Cork devices have for many years been attached to items such as keys to enable them to float and be retrievable if dropped into water, for example in harbours and marinas. These cork devices are relatively bulky and are not sufficiently buoyant to support heavy items.

More recently, various proposals have been made, for example in FR 2733482, US 2004/0137810 and GB 2406265, for devices for this purpose which incorporate an automatically inflatable bag to serve as the float. These devices are all impractical to produce economically, or else are unsafe or unreliable in operation. For example, FR 2733482 proposes a cylinder in which. acetylene gas is generated by a chemical reaction upon contact of calcium carbide with water. Even if this reaction was reliably achieved., it is clearly unsafe for use as acetylene is flammable. The proposal in US 2004/01378 10 involves breakdown in water of a barrier between two compartments within the inflatable balloon, which would be most unreliable in practice. The proposal in GB 2406265 and other known. devices involves use of a canister of compressed carbon dioxide and a trigger device which involves piercing of a seal to this canister, the trigger device being dependent on breakdown of a material on contact with water. These are expensive to produce because a canister of compressed carbon dioxide must be of metal and sufficiently robust to withstand the high pressure required to contain the gas. Moreover, they are unreliable in use in part because of frequent occurrence of air locks in the passage of water to the water degradable material, but also because the force required to pierce such a seal is considerable and may not be achieved.

These problems were all addressed by the device disclosed in our prior application, W02007/088347. In this document, a floatation device comprises an inflatable bag of substantially waterproof and air impervious matenal, a container of compressed gas, trigger means associated with the container and operable upon immersion of the device in water to open the container and allow gas from the container to inflate the bag. The device fUrther comprises a casing in which the bag, the container and the trigger means are housed, and means for attachment of the device to another article. The trigger means comprises a valve mourned on the container and connecting the container to the inflatable bag, retainer means operative to hold said valve in a closed condition, and water reactive means which, upon contact with water, serves to release the retainer means and allow the valve to open.

Each of the above described devices faces a design trade off between competing features affecting overall performance. For instance, a smaller device may be more appealing to users, particularly if attached to hand carried or operated. articles such as keys, wallets or mobile telephones. Nevertheless, a larger device may contain a larger supply of compressed gas andlor a larger inflatable bag which can enable heavier objects to remain buoyant when attached to the device. Conversely, a larger device typically has a greater overall weight which can adversely affect the floatation capacity of the device and fui-thennore, a heavier device (or one having a larger inflatable bag) may sink deeper underwater before sufficient inflation of the bag occurs to return the device and attached articles to the surface. On one level, this increases the chances that the device will sink too far for the inflation of the bag to overcome additional water pressure sufficiently to ensure a return to the surface. On a second point, it may delay the return to the surface of the device, causing the device to resurface at a distance from the original inmiersion point and thus limiting the chances of the articles being recovered.

It is therefore an object of the present invention to provide a floatation device which at least partially overcomes or alleviates the above problems.

According to a first aspect of the present invention there is provided a floatation device comprising: an inflatable bag of substantially waterproof and air impervious material, a container of compressed gas, trigger means associated with the container and operable upon immersion of the device in water to open the container and allow gas from the container to inflate the bag, a casing in which the bag, the container and the trigger means are housed, and means for attachment of the device to another article, characterised in that the container comprises one or more hinged sections adapted to hinge outwardly in response to immersion of the device in water.

The hinged sections thereby provide additional drag impeding sinking of the device after immersion in water. This slows the sinking of the device which in turn enables sufficient inflation of the inflatable bag to occur at a lesser depth reducing the chances of a failure of inflation to return the device to the surface andlor the potential distance from the immersion point to where the device resurfaces.

In order to allow ingress of water to the trigger means, the casing may be adapted to provide one or more openings. The openings may be provided between hinged sections or may be provided through hinged sections as appropriate. The size of the openings may be selected so as to reduce the chance of accidental triggering when exposed to moist air, precipitation or liquid spillage but to ensure triggering following immersion in a suitable depth of water. In particular, this may involve S selecting the size of the openings such that the typical surface tension of water droplets would prevent ingress of water but such that once immersed in water at a threshold depth, the water pressure overcomes the surface tension.

The casing may comprise the one or more hinged sections and a casing frame upon which the one or more hinged sections are mounted. The casing frame may be adapted to connect the casing to the container and/or the attachment means. The hinges of the hinged sections may take any suitable form. In one embodiment, the hinge may be embodied by pins inserted into corresponding pivot points in the casing frame. Preferably, the frame and or hinged sections are adapted to restrict the hinging of the hinged sections beyond a predetermined limit. Preferably, the predetermined limit is hinging to a position substantially perpendicular to the frame or to the original axis of the hinged section.

The hinged sections may be biased to hinge outwardly in response to immersion in water. In such an embodiment, the hinged sections may be retained in position against the bias by one or more water reactive means. The water reactive means may be water soluble means. In one embodiment, the water soluble means may comprise water soluble members. Said members may be substantially rigid or may be substantially flexible. The members may be adapted to hold ends or edges of the hinged sections to ends or edges of adjacent hinged sections or the casing frame.

The hinged sections and the casing frame may be provided with suitabl.e openings or formations to facilitate fins hold.

The hinged sections may be biased by inherent elastic rebound against the water reactive means. Additionally or alternatively, the hinged sections may be biased by over packing of the inflatable bag or by subsequent inflation of the inflatable bag in response to immersion in water.

The hinged sections may comprise a hinged section frame and a hinged section panel. The hinged section panel may be releaseably attached to the hinged section frame. This can enable the replacement on one panel by an alternative decorative panel, if desired or required.

The casing may additionally comprise an end cap. The end cap may be adapted to rupture or be ejected in response to immersion in water. The rupture or ejection may be achieved by inflation of the inflatable bag. In the event that the water reactive means comprises a cap, this may be retained in position using suitable inter engaging formations.

In embodiments wherein the cap is adapted to rupture or be ejected in response to immersion in water, the cap may be integrated into or otherwise releaseably connectable to a bracket. If the bracket and the attachment means are both connected to an article, this allows the floatation device to be normally retained in a first orientation relative to an article, particularly an elongate article, but be free to move to a second orientation relative to an article following immersion in water.

The hinged sections may be hinged at an opposite end of the floatation device to the attachment means. In this manner the hinged sections act to slow the sinking of the floatation device without significantly impeding the rising of the floatation device.

This is because the hinged sections are held open whilst there is an overall sinking force on the floatation device and will hinge shut when there is an overall rising force of the floatation device following inflation of the inflatable bag.

The hinged sections may be arranged substantially symmetrically about an axis of the device. This can help to maintain the device axis in an upright aligmnent during immersion.

The attachment means may be provided on a base section of the casing. The base section may be releaseably attachable to the rest of the device. The releasable attachment may be achieved by the provision of suitable inter engaging formations on the base and the casing frame.

In a preferred embodiment, one or more flexible sheets may be connected between the edges of adjacent hinged sections. The one or more flexible sheets may be adapted to be folded within the casing before immersion and extend between the adjacent hinged sections once the hinged sections open in response to immersion.

The folding of the one or more flexible sheets may be adapted to provide a biasing force to help urge the hinged sections outwardly upon immersion. The addition of the one or more flexible sheets increases the drag on the device when siiildng and thus further slows the sinking.

The trigger means may comprise a valve mounted on the container and connecting the container to the inflatable bag, retainer means operative to hold said valve in a closed condition, and water reactive means which, upon contact with water, serves to release the retainer means and allow the valve to open. The valve may be spring biased into an open condition in some embodiments, but in other embodiments it may be spring biased into a closed condition. In the latter embodiments, the spring itself comprises the retainer means. Preferably, in such embodiments, the trigger means is adapted to bias the valve into an open condition following activation.

The water reactive means is preferably provided in the fonn of at least one water reactive band (strip) of material. A starch based polymer is a suitable material S for such a band. The water reactive means for the trigger means may be combined with the water reactive means retaining the hinged section in position.

Advantageously, the container may be of plastics material and the compressed gas may suitably be a hydrogenated chiorofluorocarbon compound. This gas requires compression at far lower pressures than carbon dioxide, and can safely and suitably be contained in a low cost container of plastics material similar to the housing of a conventional inexpensive cigarette lighter. Moreover, it is safe to use and not an enviromnental hazard.

In a further development of the invention, an illumination means is advantageously mounted inside the inflatable bag. The illumination means may comprise a light emitting diode (LED), an incandescent bulb or the like. The illumination means may be provided with at least one battery. Preferably suitable conducting elements are provided between the at least one battery and the illumination means. The at least one battery and the illumination means may be provided within a common housing. Alternatively, the at least one battery and the illumination means may he housed separately with the conducting elements therebetween. The illumination means may be adapted to illuminate in response to inflation of the bag. This may be achieved by any suitable activation arrangement. In a preferred embodiment, the activation arrangement comprises a strip of insulating material arranged so as to block the connection between the at least one battery and one of the conducting elements, the strip being further connected to the trigger means or the bag such that the strip of insulating material is automatically withdrawn from blocking the connection between the at least one battery and the conducting element upon inflation of the bag and/or immersion in water.

The illumination means may be attached within the inflatable bag by providing a projection on the housing of the illumination means. The projection may be attached to the bag by means of a clip, 0-ring or other fixing means fitted over said projection from outside the bag. Suitable fixing means may include dedicated fixing components or may include adapted components such as string, cable cord, wire or the like. The aforesaid clip, 0-ring or fixing means may be provided with an additional, preferably expansible, loop to facilitate retrieval of the device upon flotation. In such arrangements, the illumination means is preferably attached at a location remote from the neck of the bag. In an alternative arrangement, the illumination means may be mounted within the bag on the conductors or an extension of the conducting elements. In such arrangements, the illumination means is preferably mounted within the neck of the bag or adjacent to the neck of the bag.

In order that the present invention is more clearly understood, a specific embodiment will now be described, with reference to the accompanying drawings, in which: Figure 1 is an outer view of a fioatati.on device according to the present invention; Figure 2 is a cutaway view of a floatation device according to the present invention; Figure 3 is an exploded view of a floatation device according to the present invention; Figure 4 is an exploded view of the upper section of the casing of an alternative embodiment of a floatation device according to the present invention; Figure 5 is an outer view of a floatation device of the present invention wherein the inflatable bag is inflated; and Figure 6 is a cutaway view of an alternative embodiment of a floatation device.

Turning now to figure 1, an outer view of a floatation device 1 according to the present invention is shown.

The flotation device comprises an outer casing 10 made up of a base section 11 and an upper section 12. The base section 12 is thrther provided with an attachment means 13, shown here as a ioop by means of which the floatation device 1 may be attached to other articles, such as keys, wallets and mobile telephones (not shown).

In figure 2, a cutaway view of the floatation device 1 shows some of the internal features of the device 1. In particular, the floatation device 1 comprises a container of compressed gas 20, an inflatable bag 30 and a trigger means 40. The inflatable bag 30 is comprised of substantially waterproof and air impervious material.

The trigger means 40 is associated with the container 20 and operable on immersion of the device 1 in water to open the container 20 and allow gas from the container 20 to inflate the bag 30. Also apparent in figure 2 are thither aspects of the casing 10 such as the end cap 14 and the internal frame 15.

Turning now to figure 3, an exploded view of the flotation device 1 is shown.

In the exploded view, the container 20 can be seen to be formed from two parts 21, 22 and to be provided with a valve 23 with an actuation tab 24. The inflation bag 30 has a neck 31 which is fitted around the valve 23 so as to form a substantially airtight seal.

The valve 23 is operated by the trigger means 40 to allow gas from the container 20 to inflate the bag 30 upon immersion in water.

The trigger means 40 comprise a spring 41 retained wider tension within a water reactive band 42, the spring and band being mounted between an upper surface of container 20 and a lever 43. The band 42 is comprised of a water soluble material such as a starch based polymer. Upon immersion in water, the band 42 dissolves allowing the spring 41 to extend. The extension of spring 41 raises one end of lever 43 such that the other end of lever 43 acts on the valve actuation tab 24 to open valve 23. Gas from within the container cart then flow through valve 23 into the inflatable bag 30.

Inflation of the bag 30 causes the bag to press against end cap 14. When sufficient gas is in the bag, this overcomes the friction or inter-engaging formations holding end cap 14 in place. The end cap 14 is thereby ejected away from the device 1 and the inflatable bag 30 can continue to inflate externally of the casing 10.

Figure 3, also clearly shows that the upper section 12 of the casing is comprised of a plurality of hinged sections 16, 17, the hinged sections 16, 17 hinged about pivot points iSa on the upper part of the internal frame 15. The hinged sections 16, 17 are adapted to hinge outwards upon immersion in water. As can be seen in the figures, the hinged section 16 may comprise a hinged section frame 1 6a and a hinged.

section panel 1 6b. The skilled man will equally appreciate that the hinged section 16 might equally be provided as a substantially integral component. Providing a separate panel allows a user (or a supplier) to replace a panel 16b with an alternative panel provided with a decorative design or colour on its outer surface.

The pivot points 15a and hinged sections 16, 17 are adapted to prevent the hinged sections 16, 17 hinging beyond substantially perpendicular to the axis of the frame 15. Prior to immersion, the hinged sections 16, 17 are retained in position relative to each other and the rest of the device by the provision of water reactive members 18, 19. The water reactive members 18, 1? are adapted to be fitted through or against cooperating features of tabs 16z, 17z provided at the lower edge of the hinged sections 16, 17. Tn the example shown, the members 18 comprise substantially rigid shaped rods and the members 19 comprise substantially rigid straight rods. In alternative arrangements the members 18, 19 can be replaced with one or more flexible cables or the like tied between tabs 1 6z, 1 7z.

As in the case of the trigger mechanism 40, the water reactive members 18, 19 are comprised of a water soluble material such as a starch based polymer. Upon immersion in water, the members 18, 19 dissolve allowing the hinged sections 16, 17 to hinge outwards. To enable water to reach the members 18, 19 (and indeed trigger mechanism 40) the adjacent edges of hinged sections 16, 17 do not provide a watertight seal. In some embodiments, one or more openings may be provided in sections 16, 17 to facilitate water ingress.

The outward movement of the hinged section 16, 17 can be aided by a suitable bias. This may be provided by elastic rebound of the hinged sections 16, 17 against being held in place by the members 18, 19 and/or the end cap 14. An additional urge to hinge outward can be provided by the initial inflation of the bag 30.

In use, the floatation device would typically be attached to an article by the attachment means 13. When dropped into water, the article would exert a sinking force on the device via attachment means 13 tending to orientate the device with the attachment means 13 dowrnnost. Once the device 1 is immersed, the menThers 18, 19 will start to dissolve allowing the hinged sections 16, 17 to hinge outwardly. Whilst the device I continues to sink, the hinged sections 16, 17 provide drag slowing the sinking of the device I. In an alternative embodiment of the device 1, shown in figure 4, there is provided flexible sheet 50 connected between the edges of adjacent hinged sections 16, 17. The flexible sheets 50 may be folded within the casing 10 before the device 1 is immersed in water. The flexible sheets 50 further increase the drag against sinking provided by the hinged sections 16, 17 without significant additional impediment to the rising of the device 1 after inflation of the bag 30 commences.

As or after the members 18, 19 dissolve, the band 42 also dissolves opening valve 23 and thereby enabling inflation of the bag 30. As inflation of bag 30 continues, end cap 14 is ejected as described above and the bag continues to inflate outside the casing as shown in figure 5. Eventually, the inflation of the bag 30 increases the buoyancy of the device 1 and attached article sufficiently that it begins to rise within the water. As this occurs, the hinged sections 16, 17 will tend to hinge toward the shut position thus providing minimal impediment to the floatation device I rising to the surface of the water.

The slowed sinking of the device 1 provided by the hinged section 16, 17 enables inflation of the inflatable bag 30 to occur at a lesser depth. This reduces the chances of a failure of inflation to return the device I to the surface and/or the potential distance from the irnniersion point to where the device 1 resurfaces. An additional benefit of the hinged sections 16, 17 is that their outward hinging allows ready ingress of water to the trigger means 40 ifirther facilitating early inflation of the bag 30.

The device 1 may additionally be provided with an illumination means within the bag 30 and illuminated in response to inflation of the bag 30. The illumination means may comprise an LED or the like and be powered by one or more batteries connected to the LED via suitable conducting elements. The illumination means and the at least one battery and may be provided within a common housing or may be housed separately with conducting elements therebetween. In order to facilitate activation of the illumination means, a strip of insulating material is arranged so as to block the connection between the at least one battery and one of the conducting elements, the strip being further connected to the trigger means 40 or the bag 30 such that the strip of insulating material is automatically withdrawn from blocking the connection between the at least one battery and the conducting element upon inflation of the bag 30.

Turning now to figure 6, a further alternative embodiment is shown. In this embodiment, a water soluble band 45 replaces both the water soluble band 42 of the trigger means 40 and the water reactive members 18, 19. The band 45 is looped over spring 41 and the container 20 within both the lever 43 and base 11. The band 45 is threaded between the frame 1 6a and panel I 6b of the hinged sections 16. The band 45 thus provides a common means by which inflation of the bag 30 and hinging of the hinged sections 16, 17 can be controlled. A further feature illustrated in figure 6 is the provision of snap fit elements 15b of the casing frame 15, enabling the releasable attachment of the base 11 to the rest of the device 1. The snap fit elements allow for replacement of a container 20, bag 30, trigger means 40, hinged sections 16, 17 and end cap 14 after triggering. These components of the device 1 can therefore be sold as a refill unit.

It is of course to be understood that the invention is not to be restricted to the details of the above embodiment, which is described by way of example only.