BACKGROUND OF THE INVENTION

(1 ) Field of the Invention

This invention relates to a protective shelter for bushfires or other natural disasters.

(2) Prior Art

Many people are killed in bushfires by asphyxiation, burns to the body and/or heat radiation in the generally short time it takes a bushfire to pass a given point. For example, many bulldozer operators have been killed when the bushfires have suddenly changed direction while the operators were making firebreaks. In some cases the operators have been killed and the bulldozers have been undamaged. SUMMARY OF THE PRESENT INVENTION

It is an object of the present invention to provide a protective shelter which people can use to provide shelter while a bushfire moves past.

It is a preferred object to provide a shelter which is self-inflating to its desired shape by the heat from the bushfire.

It is a further preferred object to provide a shelter which can be transported in a small container or canister which can be fitted on e.g. a bulldozer or fire-truck.

It is a further preferred object to provide a shelter which is gas tight against chemical fumes and which incorporates a supply of oxygen and/or means to filter the air inside the shelter to prevent asphyxiatio when people are using it.

It is a still further preferred object to provid a shelter which can be easily anchored to prevent the winds which accompany a bushfire from blowing it away. Other preferred objects will become apparent from the following description.

In one aspect, the present invention resides in a protective shelter against bushfires or other natural disasters including: a flexible wall and roof structure adapted to be erected from a folded storage and transport position, to an erected protective position, the structure comprising one or more wall and rod panels formed of an inner skin and outer skin with heat insulating means interposed between the skins and means to activate the heat insulating means.

The shelter may be domed or "igloo" shaped, or may be tent or "teepee" shaped, the wall and roof being preferably formed in one piece. Preferably the shelter has an integral floor fixed around the periphery of the wall. Preferably the wall is formed of "Kevlar"

(Registered Trade Mark of DuPont Corporation), aluminium or other metal foil skins which are generally gas imper¬ meable. The outer skin may be coated with heat reflecti paint, which is preferably intumescent, and so foams whe subjected to heat.

Heat (or cold) insulating material may be provided between the inner and outer skins and may comprise rock wool or an insulating foam, the latter being preferably foamed by the gas which inflates the shelter.

Preferably the inflation of the shelter occurs automatically, the heat generated by an approaching bushfire triggering a heat sensitive valve or membrane which releases the gas from a pressurized canister. To protect the user from skin burns on the inner skin, the shelter may be lined with a wool, wool/ titanium woven fabric or other insulating material liner BRIEF DESCRIPTION OF THE DRAWINGS To enable the invention to be fully understood, a number of preferred embodiments will now be described

with reference to the accompanying drawings, in which: FIG. 1 is a front view of a first embodiment of the shelter;

FIGS. 2 and 3 are respective sectional views, 5 taken on line A-A on FIG. 1, of alternative wall con¬ structions of the shelter.

FIG. 4 is a perspective view of a second embodi¬ ment of the shelter, parts being broken away for clarity; FIG. 5 is a sectional view of the part broken 10 away in FIG. 4 in more detail.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, the shelter 10, when erected, has a substantially domed-shape with an integral wall and roof structure 11 which is closed on its under- 15 side by an integral floor (not shown). A door panel 12, hingedly mounted on one side, provides access to the interior of the shelter. (In a modified form - not shown - an access passage in the manner found with an igloo may be provided to provide protection for the door panel). 20 For transport, the shelter 10 is folded and stored in a canister which may be mounted on a vehicle (e.g. a bulldozer or fire-engine) or dropped from an air¬ craft using a parachute.

Referring to FIG. 2, the wall structure 11 has 25 an outer skin 14 of "Kevlar" and inner skin 15 formed of aluminium foil, the skins being joined by strips 16, provided with gas holes 17 to form a series of inter¬ connected compartments 18, each filled with "rock wool". Heat reflective intumescent paint 19 is applied to the 30 outer skin 14, the paint foaming when subjected to heat to form an additional heat insulating barrier. A wool/ titanium fibre fabric 20 e.g. of the type used in fire¬ proof clothing, is provided as an inner liner to prevent the users from being burnt on the inner skin 15. A 35 container of gas 21 is provided inside the folded shelter,

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the container having a heat-sensitive valve which connects the container to the interior of the wall structure. When a fire approaches, the valve is oper¬ ated to release the gas into the wall structure, causing the shelter to be inflated and erected.

When the bushfire approaches and passes, the "rock wool" tends to expand to fill the compartments and make the shelter rigid. The combination of the paint 19, the metal skins 14 and 15, the "rock wool" in the compart- ments 18 and the wool fabric liner 20 limits the heat ente ing the shelter and so providing protection for the users until the fire has passed.

In the embodiment shown in FIG. 3, the compart¬ ments 18 are dispensed with and the container is filled with a foamable insulating material and a gas. When the valve is operated, the insulating material is released and fills the cavity formed between the inner and outer skins 14, 15. The gas released from the canister both foams the insulating material and assists in inflating the shelter. The heat from the bushfire causes the insulating material to set to hold the shelter substantially rigid.

Preferably the shelter is of a bright colour to enable it to be readily located and may be both floatable and provided with pockets to be filled with sand or stones to secure it in position.

Referring now to FIG. 4, the shelter 30 is of tent or "teepee" shape with the walls and roof 31 being integrally supported by a plurality of support posts 32 connected at their apex to a central post (not shown). Each support post 32 comprises a number of lengths (e.g. 3) of PVC or other suitable tubing 33 which are interconnected by connector pieces 3 fitted to one end of each piece of tubing to engage the other end of an adjacent piece of tubing. A length of cord 35 passes through the tubing 33 to keep the pieces together when

the posts are disassembled.

The outer skin 36 is formed of aluminium foil sheet coated with intumescent paint 37, while the inner skin 38 is formed of plastics sheet. A hose 39, connected to a pressurized water tank 40, is provided in the wall and roof 31 between the inner and outer skins 38, 3β and is located by connecting strips 41 between the skins. Nozzles or holes are provided along the hose 39 to enable water to be sprayed in the cavity between the skins. As a bushfire passes over the shelter 30, the water spray is converted to steam which is released through holes 42 in the outer skin, the latent heat of vapourization of the water assisting to cool the inner skin 38. The water tank 40 may also be connected to a hose with jets which spray water over the outer skin 36 as the fire passes ovnr the shelter 30.

As the fire passes, the outer skin of the shelter 10, 30 may be consumed but such a loss is not important if the persons in the shelter are protected from the fire.

For the protection of the users, the shelter may be provided with a first aid kit, air filters (e.g. of activated charcoal), heat protective clothing or blankets and a radio. The shelter may also be provided with lights or noise generators to enable it to be easily located and with windows, and double doors, such features being desirable, but not essential, in the shelter.

It will be readily apparent to the skilled addressee that the present invention, on a smaller scale, can be used as a one-or two person sleeping pack. For use in cold climates, colder insulating material may be added or incorporated into the construction of the walls and/or floor of the bag.

Various other changes and modifications may be made to the embodiments described and illustrated without departing from the scope of the present invention.