Background Art Various types of disposable fuel burners have been described previously.

Typically, the known disposable fuel burners include a combustible liquid or gel-type fuel in a container, a wick partially immersed in the fuel, and a support for the wick through which a part of the wick projects. Some known disposable fuel burners also include a layer of porous, non-combustible material overlying and in contact with the exposed part of the wick. In these burners, the fuel impregnates the porous layer as a result of capillary action through the wick, and may be ignited. Generally, the wick support in previously known disposable fuel burners is a flat metal plate having an opening for the wick and one or two relatively smaller openings for admission of air to a compartment holding the fuel. Alternatively, some previously known disposable fuel burners have a fuel holder in the form of a squat can, the top of the can including a raised central portion holding the wick and adapted to receive a screw cap for preventing loss of fuel from the burner during transportation. Such burners are usually of multi-part construction.

Known disposable liquid fuel burners suffer from a number of disadvantages.

Disadvantages exhibited by known burners include: (a) some burners, especially those including a gel-type fuel, get very hot during use and/or following use, so that they are impossible to pick up without appropriate protection for the skin; (b) the flame tends to be unstable in the wind, making such disposable fuel burners unsatisfactory for use out of doors; (c) in burners with a liquid fuel, or those with a gel-type fuel after they have become hot in use, the fuel tends to spill from the burner easily if it is accidentally knocked over; (d) in some, the flame height, and therefore the intensity of the flame, are difficult or impossible to adjust; (e) some are a safety hazard if they are knocked onto their side while in use;

(f) in some, the flame can be difficult to relight if it is extinguished for any reason; (g) some are relatively complex and/or costly to manufacture; and (h) burners with a gel-type fuel have an ethanolic or methanolic smell when not in use and sometimes also when in use, which is undesirable in a food environment.

While not all prior art disposable fuel burners exhibit all of the above disadvantages, all exhibit at least one of these disadvantages.

Accordingly, there is a need for an improved disposable fuel burner.

It is therefore an object of the present invention to provide an improved disposable fuel burner.

Description of the Invention According to a first embodiment of the invention there is provided a disposable fuel burner including a container at least partially filled with a combustible fuel, and having a closed bottom; enclosing side walls; a wick support located above the surface of the fuel and extending between the side walls, at least part of the wick support having a well formed therein and a wick support opening at the bottom of the well, the wick support further having at least one air inlet opening; and an elongated porous wick having an end immersed in the fuel and extending through the wick support opening, the combustible fuel being ignitable at an exposed end of the wick.

Typically, the disposable fuel burner of the first embodiment has a single air inlet opening.

In one form of this embodiment, the air inlet opening is located in the well of the wick support, for example in a wall of the well, or in a bottom surface of the well. In another form of this embodiment, there is provided a cup member surrounding the air inlet opening between the wick support and the fuel, defining an enclosed space between the cup member and the wick support, the cup member having an air hole therein. In this form of the disposable fuel burner of the first embodiment, the cup member serves to contain any fuel which may leak through the air hole in the cup member, thereby substantially reducing, or preventing, the leakage of fuel through the air inlet opening in the wick support. Typically, the air hole in the cup member is arranged so that any fuel which enters the cup member can drain back into the container through the air hole.

In another form of this embodiment, the disposable fuel burner includes valve means operatively associated with the air inlet opening to inhibit leakage of the combustible fuel from the air inlet opening, such as when the disposable fuel burner is being moved or is upset from a use position, and to permit admission of air into the container when the disposable fuel burner is in a use position.

The valve means may be any convenient device which allows admission of air through the air inlet opening and into the container when the disposable fuel burner is in use, but inhibits (typically substantially prevents) fuel from leaking from the air inlet opening when the disposable fuel burner is transported or is turned sideways or upside down. Typically, in this form of the first embodiment the valve means includes a film of flexible plastic or metal sealed to the underside of the wick support (that is, the side of the wick support within the container) the film or the seal having one or more apertures whereby when the disposable fuel burner is in a use position air can pass through the air inlet opening and through the aperture(s) but when the disposable fuel burner is in a sideways or inverted position, fuel in the disposable fuel burner presses on the film and substantially closes the aperture(s) and/or causes the air inlet opening to be obstructed by the film.

For example, the film may be sealed to the wick support around the periphery of the film, the seal defining a central region of the film which is free from the wick support and which covers the air inlet opening. One or more slits may be provided in the central region. When the disposable fuel burner is in use, air enters the air inlet opening and is admitted to the container's interior via the slit or slits in the film.

However, the slit or slits are dimensioned so that fuel in the container is substantially prevented from seeping through them when the disposable fuel burner is overturned, for example. Usually, the number of slits provided is one or two, more typically one.

The slit or slits are typically straight or v-shaped, but may be any convenient shape.

In another form of the valve means, there is at least one break in the peripheral seal attaching the film described above to the wick support, the break or breaks in the seal providing an aperture or apertures for air to be admitted to the interior of the container. In this form, the film typically has no slit; that is, the break or breaks in the seal is/are the only path(s) for air admission from the air inlet opening to the interior of the container. In this form of the valve means, air is freely admitted to the interior of the container when the disposable fuel burner is in use, but if, for example, the disposable fuel burner is inverted, pressure of fuel in the disposable fuel burner on the film presses the film against the wick support and prevents egress of the fuel through the break or breaks in the seal and the air inlet opening. Typically, there is only one break in the seal.

Generally, the film is positioned on the wick support so that the air inlet opening is not in close proximity to a break in the peripheral seal, or to a slit in the film, as the case may be.

If desired, the valve means may include more than one layer of film, each layer being sealed to the wick support and/or to each other with a break in the seal of each layer of film, or with a slit in each layer of film, or with a combination of slits and seal breaks forming a path for admission of air from the air inlet opening to the interior of the container. Usually, where there are breaks in the seals of two contiguous layers of film, or slits in two contiguous layers, the breaks or slits are positioned as far from each other as possible.

The film of the valve means may be of any convenient shape, such as square, rectangular, circular, oval, hexagonal, etc. Typically, it is rectangular, square or circular. The film is typically a polymeric film such as of polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate or polyvinyl alcohol, more typically polyethylene or polyvinyl chloride. Alternatively, the film may be a film of metal, such as tin or aluminium. The film may be sealed to the wick support by any convenient means, including gluing or heat sealing, and/or soldering, welding or brazing in the case of metallic film. It will be appreciated that the material of the film, and any glue used to seal it to the wick support, must be substantially inert to and unaffected by the fuel in the disposable fuel burner.

The disposable fuel burner may additionally include a top having an opening, with the wick support being located intermediate the top and the fuel, the opening in the wick support being opposed to at least part of the opening in the top. A top, when present, and/or the well formed in the wick support, can provide protection from wind or draughts for a flame burning at the exposed end of the burner's wick. Typically the opening in the top is located directly above the wick support opening and is at least as large as, more typically larger than the wick support opening. Typically the opening in the top is circular, elliptical, square, rectangular, triangular, hexagonal, octagonal or pentagonal in shape; more typically circular. Typically the maximum dimension of the opening in the top is in the range 1 to 5 times, more typically 1.5 to 4 times and even more typically 2 to 3 times the maximum dimension of the wick support opening.

Generally the size of the opening in the top and the distance between the top and the wick support are chosen to enable the wick to be manually pushed or pulled through the support opening and at the same time provide wind protection for the flame during windy conditions.

In this form of the invention, a top may serve as a retaining means for any fuel that may leak through the air inlet opening in the wick support, especially if the air

inlet opening is positioned in a part of the wick support which is covered by the top when the disposable fuel burner is in its normal upright position.

Thus, in a second embodiment, the invention provides a disposable fuel burner including a container at least partially filled with a combustible fuel, and having a closed bottom; enclosing side walls; a first wick support located above the surface of the fuel and having a wick support opening and at least one air inlet opening therein; fuel retaining means to retain at least some of any of said fuel which leaks through said air inlet opening or openings; and an elongated porous wick having an end immersed in the fuel and extending through the wick support opening, the combustible fuel being ignitable at an exposed end of the wick.

It will be appreciated that the wick support in this form of the invention need not include a well, and may be substantially flat, or domed. However, a flat wick support, or a wick support including a well, is preferred. When the wick support is substantially flat or includes a well, any fuel which is retained in a space between the fuel retaining means and the wick support (for example as a result of leakage if the disposable fuel burner is tipped onto its side or overturned) more readily drains back into the container by soaking through the wick when the disposable fuel burner is returned to its normal upright position.

The fuel retaining means is typically a top for the disposable fuel burner, having an opening aligned with the wick support opening, the top extending to the side walls of the disposable fuel burner. Conveniently, the inner edges of the opening in such a top may be turned downwards; that is, towards the wick support.

An advantage of this disposable fuel burner, especially where the wick support is substantially flat, is that once the disposable fuel burner is righted from an overturned or sideways position, any fuel which has leaked into the space between the fuel retaining means and the wick support does not pool around the wick, and the wick may be relit readily. Additionally, the wick height may be adjusted both up and down readily by pulling it or pushing it. When pulled, the portion of the wick extending above the wick support may be lengthened, and when pushed, the wick may be caused to spread into the space between the fuel retaining means and the wick support, effectively reducing the height of the wick. In prior art disposable fuel burners, it is typically very difficult or impossible to reduce the height of a wick once it has been pulled up through a constricting opening.

In yet another form of this embodiment, the disposable fuel burner has a single air inlet opening, the air inlet opening being enclosed by a cover member on or above the upper surface of the wick support, the cover member having at least one opening therein for admission of air into the space between the cover member and the wick support. Typically, in this form the air inlet opening is located in a well in the wick support, and the cover member is formed by an inward extension of at least a part of the perimeter of the well. More typically, the inward extension of the perimeter of the well circumscribes the well, in the form of a lip. For example, the cover member may be formed from an inwardly directed lip as an inward extension around the circumference of the well, the inner edge of the lip being bent or inclining towards the well surface so as to define a small clearance, typically about lmm, therewith, which clearance provides the opening for admission of air. The air inlet in the well in the wick support is positioned in the surface of the well, within the space defined by the perimeter of the well, the well surface, and the lip.

Additionally, or alternatively, a disposable fuel burner of the second embodiment may be provided with valve means operatively associated with the air inlet opening or air inlet openings, the valve means being as described herein above with regard to the first embodiment.

Generally, in this embodiment the wick support is substantially flat in a region immediately surrounding the well, the well being formed as a depression in the substantially flat region of the wick support. Typically, the substantially flat region extends from the well substantially to the edges of the wick support and may include one or more shallow ridges, typically encircling or surrounding the well. Inclusion of such ridges tends to enhance the appearance of the disposable fuel burner.

The wick support may be attached to a portion of the fuel retaining means or it may extend to the side walls of the disposable fuel burner and be attached to the side walls, or both. The means of attachment may be any convenient means, such as gluing, welding, soldering, crimping, seaming, etc. In one disposable fuel burner according to the invention, the outer edge of both the wick support and the fuel retaining means are seamed together to an upper edge of the side walls of the disposable fuel burner.

In one form of the disposable fuel burner of the first or second embodiment, the burner further includes sealing means to substantially prevent leakage of fuel from the burner during transportation. Thus the sealing means is typically adapted to substantially prevent leakage of fuel from the disposable fuel burner if the disposable fuel burner is inverted or left on its side while the sealing means is in place.

For example, the sealing means may be a removable lid sealingly mounted to the enclosing side walls above the wick support or the top of the disposable fuel burner,

when a top is present. In one form, the removable lid is replaceable, to facilitate extinguishing a flame, when desired, when the fuel in the wick is burning.

Alternatively, the removable lid may be non-replaceable. The removable lid may for instance be a press fit into or onto the side walls of the container, or a lateral extension thereof such as an inwardly directed lip, as is conventionally the practice with the lids of cans of paint and other surface finishes. Alternatively, the lid may be removable using a conventional can opener to separate it from the container of the disposable fuel burner. As a further possibility, the removable lid may include a threaded portion and be removable from the container of the disposable fuel burner by unscrewing the lid from a corresponding threaded portion of the side walls of the container. As yet a further possibility, the removable lid may be sealed to the side walls of the disposable fuel burner by a peripheral frangible seal, to permit the lid to be removed by pulling it.

Typically, the removable lid is a lid adapted to be seamed onto a can body.

Conveniently, the removable lid may be equipped with a ring pull tab to facilitate its removal. Other forms of sealable lid will be readily apparent to persons of ordinary skill in the relevant art.

Alternatively, the sealing means may be a peelable adhesive label covering a well in the wick support, or covering the opening in a top of the disposable fuel burner, when present. The material of the label is substantially impermeable to the fuel and the adhesive is substantially unaffected by contact with the fuel. Conveniently, the adhesive label may be a flexible plastic material such as polyethylene, polypropylene, polyvinyl chloride or similar material and having peelable adhesive on at least part of one side thereof. Usually, the adhesive label is a plasticised polyvinyl chloride (PVC) or PVC-backed film of metal, paper, fabric, etc. Typically, the adhesive is an acrylic emulsion adhesive and is repositional permanent. Generally, the adhesive label has a graspable portion which may be pulled to remove the sealing means from the disposable fuel burner. It will be appreciated that the use of a sealing means in this form is most effective when the sealing means covers both the wick support opening and the air inlet opening in the wick support.

As a further alternative, the sealing means may be a plug or insert adapted to removably and sealingly fit into the well in the wick support, or into the opening in a top of the disposable fuel burner. Typically in this form, the sealing means is a plug of resilient plastic which is dimensioned to seal against a surface or surfaces of the well or opening so as to substantially prevent leakage of fuel from the disposable fuel burner if the disposable fuel burner is inverted or left on its side while the plastic plug is in place. The use of a sealing means in the form of a plug adapted to sealingly fit into the well of the wick support is most effective when the well includes the air inlet opening.

In some forms of a disposable fuel burner of the present invention, a wick protruding from a wick support opening may press against a plug inserted in a well or opening and may tend to cause the plug to lift or otherwise not to remain in place.

Accordingly a plug for use in a disposable fuel burner of the present invention typically includes retention means to retain the plug in place when the plug is fitted into the well or opening. The retention means may include, for example, one or more recesses in a portion of the plug inserted into the well or opening of the disposable fuel burner, and a corresponding number of mating protrusions may be provided on the surface of the well contacted by the plug, or in the opening in a top of the disposable fuel burner. The number and dimensions of the protrusions and recesses are adapted so that plug is insertable by manual pressure into the well or opening and is retained in place, but is removable by manually pulling or levering the plug.

Conversely, a surface of the plug which is inserted into the well or through the opening of the disposable fuel burner may include one or more protrusions, adapted to cause the plug to be retained in place when the plug is inserted into the well or opening.

Usually, in this form each protrusion includes a frangible portion adapted to break when the plug is removed from the well or opening, in order to facilitate its removal.

The protrusions typically take the form of a lug or tongue. Generally, the plug includes from 1 to 8, typically 2 to 4, more typically 2, such protrusions. For example, the plug may include a circumferential ridge protruding from the portion of the plug which is inserted into the well or opening, or two or more lugs protruding from that portion.

For ease of removal of the plug from the disposable fuel burner, the top of the plug typically includes a graspable member or means whereby leverage may be applied to the plug to remove it from the disposable fuel burner. For example, at least a part of the top of the plug may extend over an upper surface of the disposable fuel burner but be spaced apart from the surface sufficiently for a fingernail, screwdriver or other means for applying leverage to be inserted under the top for levering it off.

Conveniently, the underside of the top of the plug may include a stepped-in portion for the purpose of spacing the top apart from an upper surface of the disposable fuel burner.

It will be appreciated that the disposable fuel burner of the invention may include more than one type of sealing means such as those described above.

In another form of the disposable fuel burner of the second embodiment of the invention there is provided a disposable fuel burner including a container at least partially filled with a combustible fuel, and having a closed bottom; enclosing side walls;

first and second wick supports defining an enclosed space therebetween, the first wick support being located intermediate the fuel and the second wick support, at least one of the wick supports extending between the side stalls, each wick support having a wick support opening formed therein, the first wick support further having at least one air inlet opening and the second wick support having no air inlet opening; and an elongated porous wick inserted through the stick support openings in the wick supports, the wick having a first end immersed in the fuel and a second exposed end projecting through the wick support opening in the second wick support; wherein the wick support openings are dimensioned (i) to substantially inhibit leakage of the fuel from the disposable fuel burner through and around the wick when the disposable fuel burner is overturned or left on its side, and (ii) when the disposable fuel burner is in use, to permit sufficient fuel to reach the exposed end of the wick by capillary action to be ignitable at the exposed end or the wick and continue burning until the fuel is substantially exhausted.

Usually, the disposable fuel burner of the second embodiment has only one air inlet opening in the first wick support.

In the disposable fuel burner of the first and second embodiments, an air inlet opening is generally dimensioned and arranged such that fuel in the container no more than drips through the air inlet opening in the event the container is overturned or left on its side. Typically, an air inlet opening is from about 0.1 to 2mm, more typically 0.2 to lmm in diameter It will be appreciated that if the air inlet opening is too small, a substantial pressure difference can develop between the inside and the outside of the container when the disposable fuel burner is in use, owing to consumption of the fuel.

This pressure difference can lead to a reduction in the flow of fuel to the exposed end of the wick and so reduce the size of the flame. Usually, the air inlet opening is no larger than necessary to admit sufficient air to the container of the disposable fuel burner to prevent this from happening.

Typically, in the form of the disposable fuel burner of the second embodiment which includes two wick supports, the wick support opening in the first wick support is additionally dimentioned so as to allow any fuel which enters the space between the first and second wick supports to drain or percolate back into the fuel container, or be absorbed by the wick, when the burner is returned to a use position. Fuel which enters the enclosed space between the first and second wick supports may also drain back into the container through the air inlet opening in the first wick support.

Generally, the space defined between the first and second wick supports is sufficiently wide to substantially prevent any fuel which may leak into the enclosed space from seeping to the upper surface of the second wick support. Typically, this

enclosed space is from 4-10mm wide, more typically abut 5-7mm wide, although it may be more or less wide depending on the fuel and other dimensions of the disposable fuel burner. In the disposable fuel burner of this embodiment, if any fuel leaks from the container (for example during transportation of the disposable fuel burner or if it is turned onto its side) such as through the wick, out of the air inlet opening, or around the wick through the wick support opening in the first wick support, the leaked fuel tends to be trapped in the space between the first wick support and the fuel retaining means, and when the disposable fuel burner is righted, or becomes stationary, the fuel then returns to the container by draining back through the air inlet opening or through the wick, or it is absorbed by the wick. Thus, the disposable fuel burner of the second embodiment will not leak if shaken or dropped onto its side, unless it remains in that condition for an extended period of time.

In the form of the disposable fuel burner of the second embodiment having two wick supports, either the first or the second wick support, or optionally both, may extend between the side walls of the disposable fuel burner. Where only one of the wick supports extends to the side walls of the disposable fuel burner, the other wick support is typically supported by or secured to the wick support which extends to the side walls.

The first wick support and/or the second wick support may additionally have a well formed therein, with the wick support opening in that wick support being located substantially at the bottom of the well. Usually, the second wick support has a well formed therein. Suitably, a wick support for the disposable fuel burner, having a well formed therein, may be fabricated from T2, T3 or T4 steel.

Additionally, the wick support in the disposable fuel burner of the first embodiment, or the second wick support when present in the disposable fuel burner of the second embodiment (when the second wick support has a well formed therein) may include an inwardly directed lip around the circumference of the well, the lip being dimensioned and located to permit access to the wick for adjusting its height, and so that a flame at the exposed end of the wick is not impeded by the lip. Typically, the lip provides additional protection against wind or draughts for a flame burning at the exposed end of the wick. The lip may also provide greater ease of sealing the disposable fuel burner by the use of a sealing means as described in more detail herein above.

As described above in connection with the first embodiment, the disposable fuel burner of the second embodiment may additionally include a top having an opening, with the wick support(s) being located intermediate the top and the fuel, the opening in

the wick support (when there is only one) or the second wick support (when there are two) being opposed to at least part of the opening in the top.

In the disposable fuel burner of the first embodiment, the air inlet opening or openings may conveniently be located adjacent an edge of the wick support. Similarly, in the disposable fuel burner of the second embodiment, the air inlet opening or openings may conveniently be located adjacent an edge of the first wick support.

Usually, in this form of the invention, the disposable fuel burner includes a single air inlet opening and the disposable fuel burner further includes a weight secured to the side wall of the disposable fuel burner, or to the bottom adjacent its periphery, or to a wick support on its upper or lower surface adjacent a side wall of the disposable fuel burner, the weight being located at a position substantially diametrically or diagonally opposite the air inlet opening. The weight may be attached to an inside surface or an outside surface of the disposable fuel burner. Generally, the weight is secured to an inside surface of the container of the disposable fuel burner. In this arrangement, when the disposable fuel burner is substantially cylindrical in shape, the presence of the weight causes the disposable fuel burner to roll when it is placed on its side, until the weight is at the lowest position it can reach. In such a position the air inlet opening is at substantially the highest position it can reach and in this position the air inlet opening is typically above the surface of fuel in the disposable fuel burner. Thus fuel cannot leak through the air inlet opening in this position. The weight may be secured to the side wall of the disposable fuel burner by any convenient means such as by gluing, welding, brazing, soldering, riveting, etc. Generally, the weight is glued to the side wall.

Similarly, when the disposable fuel burner of the first embodiment includes a cup member surrounding the air inlet opening, the disposable fuel burner typically also includes a weight located substantially diametrically opposite the air inlet opening, as described above, In the disposable fuel burner of the first and second embodiments the wick support opening or openings is/are typically substantially circular. However, other shaped openings may be used, for example oval, square, rectangular, triangular, hexagonal, etc. Optionally, the wick support opening or openings may have serrated or toothed edges. It will be appreciated that the size of the wick support opening(s) in the disposable fuel burner of the invention will depend on a number of factors including the type of wick material, its thickness, and the viscosity and/or surface tension of the fuel.

Given the teaching herein, a person of ordinary skill in the disposable fuel burner art can readily determine an appropriate wick support opening size for any desired combination of wick material, wick thickness, and fuel.

The disposable fuel burner of either the first or second embodiment of the invention may further include flame extinguishing means, the flame extinguishing means being movable from a use position to an extinguishing position, wherein in the extinguishing position the flame extinguishing means causes a flame emanating from a wick of the disposable fuel burner to be extinguished. Optionally, the flame extinguishing means may have an opening and a shutter portion, wherein in the use position a flame emanating from fuel burning at an exposed end of the wick passes through the opening in the flame extinguishing means, and in the extinguishing position the shutter portion operates to inhibit air from reaching the flame, sufficiently to extinguish the flame.

Typically, the use position is a position of the flame extinguishing means when the disposable fuel burner is standing on its closed bottom on an approximately horizontal surface. The extinguishing position is typically a position to which the flame extinguishing means is adapted to move when the disposable fuel burner lies on its side, such as when the disposable fuel burner has been accidentally knocked over.

Suitably, in the first embodiment of the invention, the flame extinguishing means, when present, may be retained between a top and the wick support of the disposable fuel burner. In the second embodiment of the invention, a flame extinguishing means may be retained between the first and second wick supports, when present, or between a top and the first or second wick support. as the case may be.

For example, in a disposable fuel burner of the second embodiment, the flame extinguishing means may conveniently have a cylindrical body portion with an outwardly directed flange adjacent one end thereof and an inwardly directed flange adjacent the other end thereof and forming the shutter portion, wherein the outwardly directed flange is captive between two members selected from a first wick support, a second wick support and a top, and is adapted to be retained by one of the said members when the extinguishing means is in the extinguishing position. In this form of the invention, when the disposable fuel burner is stood on its side, the flame extinguishing means moves to a position wherein the shutter portion at least partially covers a flame burning at the exposed end of the wick and inhibits escape of combustion products from the region of the flame, sufficiently to extinguish the flame.

In another form, the flame extinguishing means is an annular disk. In this form, the disposable fuel burner may for example include a top having an opening for a flame to pass through and consisting of two spaced-apart layers having the flame extinguishing means retained in the space between the layers and adapted so that in the extinguishing position the annulus of the flame extinguishing means substantially

occludes the opening in the top, thereby substantially preventing access of air to the flame and extinguishing it.

In a still further form, the flame extinguishing means is a shutter pivotably mounted on a wick support of the disposable fuel burner of the invention, the shutter being movable in a plane substantially parallel to the wick support from a first position to a second position, wherein in the first position the shutter substantially covers a flame emanating from the end of a wick protruding from a wick support opening in the wick support, thereby extinguishing the flame, and in the second position the shutter does not occlude the flame. Typically, the shutter is a substantially flat disc or plate which may be circular, square, oval, hexagonal, teardrop-shaped or any other convenient shape. The shutter may also be domed, hemispherical or include a raised portion or region of other shape. Usually, the shutter is pivotably mounted to the wick support adjacent an edge of the shutter, for example by being pivotably mounted on a pin fixed to the wick support and passing through the shutter adjacent an edge thereof.

Conveniently, in this form of the invention the disposable fuel burner is substantially cylindrical in shape and has a weight secured to its side wall as described above, the mount for the flame extinguishing means being located on the wick support at a position diametrically opposed to the position of the weight. In this arrangement, if the disposable fuel burner is accidentally knocked over, it rolls until the weight is at the lowest point, and the flame extinguishing means hangs from its pivot mount so as to cover the wick support opening, thereby extinguishing a flame burning at a wick protruding from the wick support opening.

A further use of a flame extinguishing means, especially a shutter-type flame extinguishing means and more especially a pivotably mounted shutter-type flame extinguishing means, is as a means for adjusting the flame height or size. Thus, the flame extinguishing means may be moved to.a position wherein, when the burner is in use, the flame extinguishing means partially obscures the burner's flame, thereby reducing its height and/or size.

Generally the height of the wick is adjustable in a disposable fuel burner of the invention. Typically this is achieved by pulling or pushing the wick through the support opening or openings until the wick is at the desired height. Alternatively, where the disposable fuel burner includes a top spaced above a wick support, the height of the wick may be adjusted by pulling the wick above the top and then compressing it to a desired extent into a space defined between the top and the wick support.

Typically, a well in a wick support is a substantially spherically or conically shaped depression or is a circular depression when viewed from above the wick support, usually with sides substantially perpendicular to the bottom surface of the

depression. However, wells having other shapes such as pyramidal, or being elliptical, square, rectangular, triangular, rhombic, hexagonal. octagonal, etc., when viewed from above, or combinations thereof, may be included. Usually, the depression is spherically shaped, or circular when viewed from above with substantially perpendicular sides, More usually, the depression is circular when viewed from above with substantially perpendicular sides and is formed by stamping the well into the wick support. In the event that the burner is laid on its side and fuel drips through the air inlet opening, when the burner is returned to the upright position fuel caught between the top and the wick support preferably flows to the bottom of the well where it makes it way past the wick into the container or is absorbed by the wick. The well of the disposable fuel burner of the first embodiment may extend from the wick support opening substantially as far as the side walls. In this form, the well may be integrally formed with the side walls. Alternatively, a well in a wick support may have a diameter or maximum dimension of from about 0.1 to 0.9 times the diameter or maximum dimension of the wick support; more typically from about 0.2 to 0.8 times the diameter or maximum dimension of the wick support, even more typically from about 0.3 to 0.7 times the diameter or maximum dimension of the wick support, yet more typically from about 0.4 to 0.6 times the diameter or maximum dimension of the wick support. Usually, a well in a wick support of a disposable fuel burner of the invention is of a sufficient depth to provide protection against winds and/or draughts for a flame burning at the exposed end of the wick. Typically, a well in a wick support of a disposable fuel burner of the invention is from about 4mm to 15mm deep, more typically from about 6mm to lOmm deep, even more typically about 8mm deep.

The fuel in a burner of the present invention may be any fuel suitable for use in known disposable fuel burners. Typically, the fuel is a liquid fuel, such as methanol, ethanol, isopropanol, ethylene glycol, diethylene glycol, triethy lene glycol, tetraethylene glycol and higher ethylene glycols, propylene glycol, dipropylene glycol, tripropylene glycol and higher propylene glycols, and the lower alkyl ethers of any of the aforementioned glycols, such as methyl or ethyl ethers. The aforementioned fuels are combustible-flammable and constitute an ignition hazard to varying extents.

Surprisingly, the present inventor has discovered that the addition of a proportion of water to an alcohol or glycol provides a useful fuel for a disposable fuel burner, but substantially lowers the flash point and/or ignition hazard of the fuel.

Thus, according a third embodiment of the present invention there is provided a burner, typically a disposable fuel burner, containing a fuel consisting of an alcohol or glycol and from 1% to 30% by volume of water. Typically, the amount of water in the fuel is such that the fuel has no measurable flash point by the method of Australian Standard 2106 and is thus not a combustible liquid as defined in the Dangerous Goods

Regulations (New South Wales) 1978. Generally, the fire-point of the fuel is above its boiling point. Usually, the alcohol or glycol is methanol, ethanol, iso-propanol, ethylene glycol, propylene glycol, diethylene glycol or dipropylene glycol. More usually, the alcohol or glycol is ethanol or diethylene glycol. Even more usually, the alcohol or glycol is diethylene glycol. The ratio of fuel to water is from 99:1 to 70:30 vol:vol, more usually from 99:1 to 80:20 vol:vol, yet more usually from 97.5:2.5 to 80:20 vol:vol, still more usually from 90:10 to 80:20 vol:vol, even more usually from 85:15 to 80:20 vol:vol. One particularly preferred fuel according to this embodiment of the invention is a mixture consisting of about 85 parts by volume of diethylene glycol and 15 parts by volume of water. Such a fuel has no measurable flash point by a closed cup method, has a boiling point of about 158"C, and a fire point of about 162"C.

The disposable fuel burner of the invention is typically constructed of metal (e.g.

aluminium, steel or tin coated steel). However, other non-combustible materials such as glass or ceramic may also be used. Conveniently, the disposable fuel burner of the invention may be or include a modified can such as is used for food preservation, adapted by having a wick support opening and air inlet opening and optionally a well formed in its lid. Thus, the disposable fuel burner of the invention typically has the advantage of simplicity of construction and low cost of manufacture, compared to many prior art disposable fuel burners, for example types in which a screw cap is fitted over the wick for transportation. Additionally, a disposable fuel burner of the invention typically has greater fuel holding capacity compared to prior art disposable fuel burners of the same overall height and width but having a screw cap lid over the wick.

The disposable fuel burner of the invention may conveniently be constructed by seaming the wick support, or at least one of the wick supports when there are more than one, and the bottom, to the side walls. Suitably, the disposable fuel burner may be assembled by first seaming the bottom to one end of the side walls, filling the fuel into the container so formed, and then seaming an assembly of wick support and wick to the other end of the side walls. The assembly of wick support and wick may be fitted with a sealing means in the form of a plug and/or a peelable label either before or after it is seamed to the side walls. In one preferable assembly process, a plug and peelable label are fitted to the wick support and wick assembly prior to seaming it to the side walls and the seaming step is carried out in a partial vacuum. In another preferable assembly process, a plug and peelable label are fitted to the wick support and wick assembly, the fuel in the container is preheated, the assembly of wick support, wick, plug and label are seamed to the side walls, and the fuel is allowed to cool. In these processes, when the wick support and wick assembly is seamed onto the side walls there is produced a disposable fuel burner in which the internal pressure is lower than the external pressure. In this arrangement, a combination of plug and peelable label as sealing

means can form a substantially airtight seal to the disposable fuel burner, and the lower pressure which is thus maintained in the disposable fuel burner eliminates any problems due to excessive pressure buildup in the disposable fuel burner which could otherwise occur during storage at elevated temperature, for example.

The porous wick of a disposable fuel burner of the invention may be constructed of any material known for use in wicks of prior art disposable fuel burners. For example the wick may be a fibrous wick constructed of fibrous materials such as cotton, wool, hemp or other natural fibrous material, or it may consist of glass fibres.

A fibreglass wick, being non-combustible, is reusable. However, in use fibreglass wicks suffer from the disadvantage that they can be very difficult to relight after a first use. An alternative is the use of a wick which is composed of a natural material, such as cotton. Generally, such materials when fabricated tend to be tufted, and the presence of tufts of material at an exposed end of a wick appears to facilitate relighting of the wick. However, wicks of natural fibrous materials tend to cause excessive leakage of fuel through the wick when the burner is inverted or left on its side, and may tend to absorb too much fuel during use for efficient combustion. Surprisingly, the present inventor has found that a composite wick substantially ameliorates these difficulties with known wicks.

Therefore, in a fourth embodiment, the present invention also provides a wick for a burner, typically a disposable fuel burner, the wick consisting of a length of elongated glass fibres surrounded or overlaid at least at one end thereof with a tufted fuel- absorbent material. Typically, the tufted fuel-absorbent material is cotton, wool or hemp. More typically, the tufted fuel-absorbent material is terry-towelling. Generally, at least the portion of the wick which projects through the wick support opening in the disposable fuel burner of the first embodiment, or through the opening in the upper wick support in the disposable fuel burner of the second embodiment, is surrounded by the tufted fuel absorbent material. In another alternative at least half the length, for example the whole length, of the elongated glass fibres is surrounded by the tufted fuel absorbent material.

In another arrangement, the end of a porous fibrous wick where the fibrous wick emerges through the wick support opening may be overlaid by a batt of a fuel-absorbent material, typically a tufted fuel-absorbent material. For example, the porous fibrous wick may be a wick of glass fibres. The batt may be secured in place by sewing it to an exposed part of the fibrous wick in one or more, preferably two, places.

Alternatively, the batt may be held in position, for example, by gluing, or by a retaining disk or one or more retaining lugs attached to or formed out of the wick support.

In a further variation, the batt of fuel-absorbent material may be provided with one or more elongate extensions, each elongate extension being adapted to be inserted into one or more orifices such as slots, formed in the wick support, so as to be a sufficiently tight fit for the batt to be secured in place. An elongate extension of the batt may, but need not, be sufficiently long to extend from the orifice through which it passes into fuel in the disposable fuel burner. If an extension of the batt reaches into the fuel, the porous fibrous wick may be omitted, in which case the orifice in the wick support through which the elongate extension of the batt passes serves as a wick support openings.

The porous fibrous wick may be a loose fit in the wick support opening, especially when it is sewn to the batt of tufted fuel-absorbent material, or it may be retained in position by being a tight fit in the wick support opening. For example, the edges of the wick support opening may be crimped into the wick which passes through it.

This arrangement of porous fibrous wick and tufted fuel-absorbent batt generally provides a wider flame than can be obtained from other wick arrangements which do not include the batt. In addition, this arrangement can facilitate relighting of a flame on the burner if it has been extinguished for any reason. Ease of relighting this wick arrangement arises in part because of the greater area of fuel-soaked material which is exposed to air compared to other wick arrangements, and in part because any excess fuel, which tends to accumulate in a wick after a flame has been extinguished, may easily be eliminated from the batt by simply squeezing it between the fingers (after allowing sufficient time for the batt to cool, of course).

In this arrangement, the batt of fuel-absorbent material is typically dimensioned substantially to fill a well formed in the wick support of the disposable fuel burner.

The invention also provides a disposable fuel burner including the wick of the fourth embodiment, and a disposable fuel burner having a porous fibrous wick, an exposed end of the porous fibrous wick being overlaid with a batt of tufted fuel- absorbent material.

Typically, the wick in the disposable fuel burner of the present invention is from about 8-12 mm in thickness, and the container of the disposable fuel burner is typically a substantially cylindrical can having a diameter of from about 70-100mm, more typically about 85mm and a height of from about 40-100mm, more typically about 60mm.

Conveniently, the disposable fuel burner of the present invention may be provided with a wind shield further to protect a flame emanating from the burner when it is used outdoors. When previously known disposable fuel burners are used in even a gentle

draught, typically from 30-40% of the heat generated by the burner is lost: that is, it is not available for the intended purpose of the burner. Prior to the present invention, no combination of disposable fuel burner and wind shield was available to solve this problem.

Usually, the wind shield of a disposable fuel burner of the present invention includes at least one hole for admitting air to the wick of the burner, and the wind shield is typically positionable on or around the disposable fuel burner so that the air admission hole or holes is/are not positioned on a side of the wind shield onto which the wind is blowing or onto which draughts fall. Thus, the wind support may be any shape which is convenient. Usually it has the same cross-sectional shape as that of the disposable fuel burner. That is, if the disposable fuel burner is cylindrical for example, so is the wind shield, at least in a region of the wind shield which is adapted to fit onto the burner. Generally, the wind shield is dimensioned to be positionable on an upper surface of the disposable fuel burner when it is in use. The wind shield may include a plurality of air admission holes. In another convenient form, the wind shield is substantially circular when seen in plan view, but is substantially wider at its upper end compared to its lower end. Thus, for example the diameter of the upper end may be from 1 to 3 times, more typically from 1.5 to 2 times, the diameter of the lower end of the wind shield.

Accordingly, the invention also provides a wind shield for a burner, typically a disposable fuel burner, the wind shield having a hollow body which is open at opposite ends thereof and includes at least one air admission hole in a side of the body.

Typically, at least one air admission hole is dimensioned to permit access to a wick of a burner on which the wind shield is positioned, so that the wick may be lit when the wind shield is positioned on the burner. Preferably, two air admission holes which are dimensioned to permit access to a wick are provided. It will be appreciated that the space available between a disposable fuel burner and the bottom of a vessel being heated by it will vary from location to location or from use to use. Thus, a wind shield of the invention for use with a disposable fuel burner typically further includes height adjustment means. For example, the wind shield may consist of an outer member and an inner member adapted to slidably fit inside the outer member, means to raise and lower the inner member relative to the outer member, and means to secure the inner member at any of a plurality of selected positions relative to the outer member.

Alternatively, the body of the wind shield may include a deformable region wherein deformation of the deformable region raises or lowers one end of the wind shield relative to the other end of the wind shield. The deformable region may consist, for example, of a corrugated or concertina region, whereby pulling on the ends of the wind shield causes it to be lengthened or heightened, and pushing on the ends of the

wind shield causes it to be shortened, lowered or flattened. The deformable region may form all or part of the body of the wind shield.

In another form, the deformable region includes a plurality of bendable tabs around the perimeter of at least one end of the body of the wind shield, whereby bending the tabs outwardly or inwardly of the sides of the wind shield reduces the overall height of the wind shield, compared to when the tabs are upright and aligned with the sides of the wind shield. Conveniently, this form of a wind shield in accordance with the invention may be made from a metal can of the type used for food preservation, without a lid. Thus, a wide circular opening may be formed in the bottom of the can to allow the wind shield to be fitted over a wick and flame of a disposable fuel burner; one or more holes may be formed in the cylindrical part of the can to allow air access to the flame; and a series of bendable tabs may be created by a plurality (typically 15-20) of cuts in the open end of the cylindrical portion of the can, extending parallel to the principal axis of the can for part of the length of the can body, typically up to about half the length of the can body. By bending the tabs so formed inwardly or outwardly, typically outwardly, from the can body to varying degrees, the effective height of the wind shield may be raised from about half the length of the cylindrical portion of the can, to its full length.

Using a wind shield in accordance with the present invention, heat losses from a disposable fuel burner of the present invention, when it is used in a draught, may typically be reduced to as little as 3-5%.

Brief Description of the Drawings Figure 1 is a diagrammatic cross section through a disposable fuel burner in accordance with one embodiment of the present invention.

Figure 2 is a diagrammatic cross sectional view of the disposable fuel burner depicted in Figure 1, with its lid removed.

Figures 3A and 3B are isometric views of a second disposable fuel burner in accordance with the present invention. Figure 3A shows the disposable fuel burner with a peelable sealing means in place, and Figure 3B shows the same disposable fuel burner with the sealing means removed, in a use condition.

Figure 4 is a diagrammatic cross section through a third disposable fuel burner in accordance with the present invention.

Figure 5 is a diagrammatic cross section through a fourth disposable fuel burner in accordance with the present invention.

Figure 6A is a diagrammatic cross section through a fifth disposable fuel burner in accordance with the present invention, including a plastic sealing plug.

Figure 6B is a diagrammatic cross section through a disposable fuel burner similar to that illustrated in Figure 6A, and having in addition, a top.

Figures 7A and 7B are diagrammatic cross sections through a sixth disposable fuel burner in accordance with the present invention, incorporating flame extinguishing means. Figure 7A illustrates the disposable fuel burner in a use position, and Figure 7B illustrates the disposable fuel burner on its side with the extinguishing means in an extinguishing position.

Figure 8 is an isometric view of the extinguishing means of the disposable fuel burner illustrated in Figures 7A and 7B.

Figures 9A and 9B are diagrammatic cross sections through a disposable fuel burner in accordance with the present invention, incorporating an alternative flame extinguishing means.

Figure 10 is a partial diagrammatic cross section through a disposable fuel burner of the present invention, illustrating a wick in accordance with the third embodiment.

Figure 11 is a cross-section through a seventh disposable fuel burner in accordance with the present invention.

Figures 12A to 12C are respectively an isometric view, plan view and cross- section of a wick support for a disposable fuel burner of the invention.

Figures 13A to 13C are two isometric views and a plan view, respectively, of a wind shield in accordance with the invention.

Figure 13D is an isometric view of an alternative wind shield in accordance with the invention.

Figures 13E and 13F provide a plan view and a side elevation, respectively, of another wind shield in accordance with the invention.

Figure 14 is a diagrammatic cross-section through an eighth disposable fuel burner in accordance with the invention.

Figure 15 is a diagrammatic cross-section through an ninth disposable fuel burner in accordance with the invention.

Figure 16 is a diagrammatic cross-section through an tenth disposable fuel burner in accordance with the invention.

Figure 17A is a cross-section through a plug for use in a disposable fuel burner of the invention. Figure 17B is a diagrammatic cross-section of the plug illustrated in Figure 17A, inserted in an opening in the top of a disposable fuel burner of the invention. Figure 17C is a plan view from below of the plug illustrated in Figure 17A.

Figure 18A is a diagrammatic representation of the underside of a wick support for use in a disposable fuel burner of the invention, showing valve means in the form of a plastic film operatively associated with the air inlet opening. Figures 18B-18F are diagrammatic representations of alternative forms of the valve means.

Best Mode and Other Modes for Carrying Out the Invention Figures 1 and 2 provide diagrammatic cross-sectional views of a first disposable fuel burner in accordance with the present invention. Referring to Figure 1, disposable fuel burner 1 is generally cylindrical in shape and consists of container 5 containing wick 70 and liquid fuel 30. Container 5 consists of bottom 10, enclosing side walls 20, wick support 40 and top 50. Container 5 is closed by removable lid 80, which is fitted with ring pull tab 85. The bottom edges of side walls 20 are equipped with feet 12, 13.

Container 5 is constructed of metal. Wick 70 is of fibreglass and is partially immersed in fuel 30, the other end being supported by wick support 40 and projecting through opening 60 in wick support 40. Wick support 40 forms conical well 45 which contains opening 60 at its bottom, and is equipped with air inlet opening 47. Wick support opening 60 is disposed substantially opposite opening 55 in top 50.

Figure 2 is a view of the burner depicted in Figure 1, with its lid removed.

In use, the height of wick 70 is adjusted as desired, depending on the desired flame size, and fuel 30 is allowed to permeate to the top of wick 70. Fuel 30 is then ignited by the application of a lighted match or other ignition source to the end of wick 70. As fuel 30 burns and its level decreases, air enters through air inlet 47 in wick support 40. If it is desired to extinguish the flame, lid 80 may be temporarily replaced.

Figures 3A and 3B are isometric views of a second disposable fuel burner in accordance with the present invention. Figure 3A shows the disposable fuel burner with a peelable sealing means in place, and Figure 3B shows the same disposable fuel burner with the sealing means removed, in a use condition. Referring first to Figure 3A, disposable fuel burner 100 consists of container 105 having cylindrical side walls 120 and a bottom sealed to side walls 120 by peripheral seam 110. At the other end of container 105 is wick support 140 extending to side walls 120 and sealed to side walls 120 by peripheral seam 141, forming circumferential groove 142 in wick support 140.

Prior to use of disposable fuel burner 100, it is provided with peelable label 160 which is peelably adhered to wick support 140. Peelable label is an approximately square piece of thin pliable plastic material which is substantially inert to fuel (not seen in Figure 3A or 3B) in container 105, and includes raised corner portion 165 which is not adhered to wick support 140. When disposable fuel burner 100 is to be used, corner portion 165 of label 160 is grasped and pulled, thereby peeling label 160 from wick support 140.

When in place, peelable label 160 covers well 145 in wick support 140, which are best seen in Figure 3B. Label 160 provides a sufficient seal over well 145 to prevent any fuel from container 105 which leaks into well 145 from escaping from well 145.

Well 145 consists of substantially circular bottom surface 146 having air inlet opening 147 and a wick support opening (not seen in Figure 3B) formed therein, and having sides 148 substantially perpendicular both to bottom surface 146 and to the surface of wick support 140. It will be appreciated that air inlet opening 147 could also be provided in side 148 of well 145, rather than in bottom surface 146. Wick 170 projects through the wick support opening in well 145, and has a distal end which is immersed in fuel (not shown) held in container 105. Wick 170 may be formed from a bundle of glass fibres, or it may be made of terry-towelling, or it may be a combination of glass fibres and tufted material, in accordance with the fourth embodiment of the present invention.

In use, after peelable label 160 is removed from disposable fuel burner 100, wick 170 may be adjusted by pulling or pushing it to a desired height, and fuel impregnating the wick 170 may be ignited.

Figure 4 illustrates a third disposable fuel burner in accordance with the present invention. Referring to Figure 4, generally cylindrical disposable fuel burner 200 consists of container 205 having sides 206 and closed bottom 210, and holding liquid fuel 230. Above the surface of fuel 230 are upper and lower wick supports 241, 242 defining enclosed space 265 between them and extending to side walls 206. Upper wick support 241 is generally flat but includes well 250 substantially in its centre and shallow ridge 246 encircling well 250. At the bottom of well 250 is wick support opening 261, which is aligned with wick support opening 262 in lower wick support 242. One end of wick 270 passes through wick support openings 261, 262, and is somewhat flattened. The other end of wick 270 is immersed in fuel 230. Wick support 242 is equipped with air inlet opening 247 adjacent one edge of a substantially flat, depressed part of wick support 242, and weight 280 is located adjacent side 206 at a position diametrically opposite air inlet opening 247. If disposable fuel burner 200 falls onto its side, weight 280 causes burner 200 to roll to a position at which weight 280 is at the bottom, thereby raising air inlet opening 247 above the surface of fuel 230 and preventing fuel from leaking from air inlet opening 247.

Figure 5 illustrates a fourth disposable fuel burner in accordance with the present invention. Referring to Figure 5, disposable fuel burner 300 consists of container 305 having sides 306 and closed bottom 310, and holding liquid fuel 330. Above the surface of fuel 330 is lower wick support 342, having depression 343 formed therein, with wick support opening 362 and air inlet opening 347 being formed in depression

343. Lower wick support is other wise generally flat, but has shallow ridge 346 encircling depression 343. Upper wick support 341 is a press fit into the top of depression 343 in lower wick support 342. Upper wick support 341 includes well 350 which has wick support opening 361 formed therein, wick support openings 361 and 362 being aligned. Enclosed space 365 is defined between upper wick support 341 and lower wick support 342. One end of wick 370 passes through wick support openings 361, 362, and is somewhat flattened. The other end of wick 370 is immersed in fuel 330.

Figures 6A and 6B are cross-sections through a fifth disposable fuel burner in accordance with the present invention, including a plastic sealing plug. Referring to Figure 6A, generally cylindrical disposable fuel burner 400 consists of container 405 having sides 406 and closed bottom 410, and holding liquid fuel 430. Above the surface of fuel 430 are upper and lower wick supports 441, 442 defining enclosed space 465 between them and extending to sides 406. Upper wick support 441 includes well 450 substantially in its centre. Wick support opening 461 is aligned with wick support opening 462 in lower wick support 442. One end of wick 470 passes through wick support openings 461, 462 and is somewhat flattened at that end, and the other end is immersed in fuel 430. Wick support 442 is equipped with air inlet opening 447.

Disposable fuel burner 400 is further equipped with plastic sealing plug 480 fabricated from resilient plastic and having a top and straight sides dimensioned to be a press fit into well 450. To facilitate sealing, the sides of plug 480 include a circumferential rib 485. The sides of well 450 include a recessed portion at their lower ends for receiving circumferential rib 485 when plug 480 is pressed into place. Figure 6B illustrates a similar disposable fuel burner to that illustrated in Figure 6A, but without plug 480.

and further including top 490 having opening 495 therein, opening 495 being opposed to wick support opening 461. Top 495 confers additional wind protection against wind and draughts for a flame emanating from the exposed end of wick 470 when disposable fuel burner 400 is in use.

Figures 7A and 7B are cross-sections through a sixth disposable fuel burner in accordance with the present invention, incorporating flame extinguishing means.

Figure 7A illustrates the disposable fuel burner with the flame extinguishing means in a use position, and Figure 7B illustrates the disposable fuel burner on its side with the flame extinguishing means in an extinguishing position. In Figures 7A and 7B, like items are given like numbering.

Referring to Figure 7A or Figure 7B, generally cylindrical disposable fuel burner 600 consists of container 605 having sides 606 and closed bottom 610, and holding liquid fuel 630. Above the surface of fuel 630 is lower wick support 642 having wick support opening 662 and air inlet opening 647 formed therein. Upper wick support 641

has well 650 formed therein, and wick support opening 661 formed in well 650. Upper wick support 641 also includes annular opening 644 substantially concentric with well 650. The central portion of upper wick support 641 is spaced from lower wick support 642 by circular spacer 645. Flame extinguishing means 680 is inserted through annular opening 644 and held captive in the space between upper and lower wick supports 641, 642 by a means of outwardly directed flange 682 at one end of flame extinguishing means 680. As best seen in Figure 8, flame extinguishing means 680 has cylindrical sides 681 and also includes at its upper end inwardly directed flange 684 which provides a shutter portion of the top of flame extinguishing means 680, and defines opening 686. In a use position opening 686 is opposed to wick support opening 661 so that a flame emanating from an exposed end of wick 670 when disposable fuel burner 600 is in use can pass through opening 686. When disposable fuel burner 600 stands on its side, for example when it is overturned accidentally, flame extinguishing means 680 falls to an extinguishing position as illustrated in Figure 7B, but cannot escape annular opening 644 because flange 682 is wider than the dimension of annular opening 644. In the extinguishing position, a flame emanating from the exposed end of wick 670 can no longer escape through opening 686. Thus carbon dioxide and other combustion products from the flame are trapped in flame extinguishing means 680 by shutter portion 684 and the sides of flame extinguishing means 680, preventing access of air to the flame and thereby extinguishing it.

Figures 9A and 9B are diagrammatic cross sections through a disposable fuel burner similar to that illustrated in Figure 6A, incorporating an alternative flame extinguishing means. Figure 9A illustrates the disposable fuel burner with the flame extinguishing means in a use position, and Figure 9B illustrates the disposable fuel burner on its side with the flame extinguishing means in an extinguishing position. In Figures 9A and 9B, like items are given like numbering.

Referring to Figure 9A, generally cylindrical disposable fuel burner 800 consists of container 805 holding combustible fuel 830 and having upper and lower wick supports 841, 842 supporting wick 870. Wick 870 has one end protruding through upper and lower wick supports 841, 842, and is somewhat flattened at that end. The other end of wick 870 is immersed in fuel 830. Container 805 is also equipped with a top formed from two spaced apart but substantially parallel layers 850, 855 each having an opening therein opposed to the exposed end of wick 870. Captive between layers 850, 855 is annular disk 884 having hole 886 therein. Disk 884 forms a flame extinguishing means in disposable fuel burner 800. As seen in Figure 9A, in a use position, disk 884 is located so that hole 886 is opposed to the exposed end of wick 870 whereby a flame caused by fuel burning at the exposed end of wick 870 may pass through hole 886. In an extinguishing position, as seen in Figure 9B, disk 884 slides

so that the opening in top layers 850, 855 is closed by a portion of disk 884 which acts as a shutter, preventing sufficient air to reach a flame burning at the exposed end of wick 870, and thereby extinguishing the flame.

Figure 10 illustrates a partial cross section through a disposable fuel burner of the present invention, showing a wick in accordance with the third embodiment of the present invention. Referring to Figure 10, there is illustrated a cut away portion of a wick support 940 having air inlet opening 947 and wick support opening 960 formed therein. An end of wick 970 is immersed in a liquid fuel 930, and the other end projects through wick support opening 960 and is supported by wick support 940.

Wick 970 includes core 975 of a plurality of glass fibres, one end of which is immersed in fuel 930. The other end of core 975 is surrounded by a layer of terry towelling 976, the combination of core 975 and terry towelling layer 976 passing through wick support opening 960. In use, fuel 930 rises through core 975 by capillary action between the glass fibres which make up core 975 and is absorbed by terry towelling layer 976 sufficiently for fuel 930 to be lit at the exposed end of wick 970. If the resulting flame is extinguished for any reason, it may be readily relit.

Figure 11 is a cross-section through a seventh disposable fuel burner in accordance with the present invention. Referring to Figure 11, generally cylindrical disposable fuel burner 1000 consists of container 1005 having sides 1006 and closed bottom 1010, and holding liquid fuel 1030. Above the surface of fuel 1030 is wick support 1040 extending to sides 1006. Wick support 1040 includes well 1050 substantially in its centre, well 1050 having wick support opening 1060 formed therein.

Wick support 1040 also includes lip 1048 extending inwardly around the circumference of well 1050, to provide additional wind protection to a flame burning at the exposed end of wick 1070. The exposed end of wick 1070 passes through wick support opening 1060 and is somewhat flattened at that end. The other end of wick 1070 is immersed in fuel 1030. Wick support 1040 is equipped with air inlet opening 1055 and around air inlet opening 1055 between wick support 1040 and the surface of fuel 1030, is cup member 1065 secured to the lower surface of wick support 1040 and defining enclosed space 1067 between cup member 1065 and wick support 1040. Air hole 1066 is formed in a lower portion of cup member 1065. Disposable fuel burner 1000 is also provided with weight 1045 secured to the underside of wick support 1040 and positioned substantially diametrically opposite air inlet opening 1055.

It will be appreciated that although disposable fuel burner 1000 is shown equipped with lip 1048, this lip feature may also be included in other disposable fuel burners in accordance with the first embodiment of the invention, or in accordance with the second embodiment of the invention, where the wick is located in a well in the upper wick support.

During transportation of disposable fuel burner 1000, for example, fuel 1030 may splash or leak into enclosed space 1067 through air hole 1065. However, leakage of fuel 1030 from disposable fuel burner 1000 is minimised because fuel 1030 may drain back into container 1005 through air hole 1065, and because the amount of fuel 1030 which could escape from disposable fuel burner 1000 through air inlet opening 1055 is greatly decreased, being at most only such amount of fuel 1030 which finds its way into enclosed space 1067.

Figures 12A to 12C are respectively an isometric view, plan view and cross- section of a wick support for a disposable fuel burner of the invention. Referring to Figures 12A to 12 C, wick support 1140 is a generally flat metal disc having a raised rim 1145 adapted to be sealingly attached to the body of a food storage can or similar, and having substantially central well 1150 and circular shallow ridge 1146 which encircles well 1150 and is substantially concentric with well 1150.

Well 1150 includes central wick support opening 1160 and air inlet 1147. Well 1150 forms a substantially spherical depression in the wick support 1140 illustrated.

However, well 1150 could be any other selected shape such as substantially square, triangular, rectangular, circular, elliptical, rhombic. hexagonal and octagonal when seen in plan view, in each case having sides substantially perpendicular to the bottom of well 1150.

Figures 13A to 13C illustrate a wind shield in accordance with the present invention. In Figs. 13A and 13B, the wind shield is seen in isometric projection. In Fig. 13A, the wind shield is seen in a full height condition, and in Fig. 13B it is seen in a reduced height condition. Fig. 13C provides a plan view of the wind shield in the reduced height condition shown in Fig. 13B.

As shown in Figs. 13A to 13C, wind shield 1200 is constructed from a metal can body, and has an open top 1220 with body 1210 in the form of a cylinder. An opening 1240, best seen in Fig. 13C, is formed in base 1230 of the metal can to allow wind shield 1200 to be placed around the wick of a disposable fuel burner. A plurality of tabs 1270 are formed in sides 1210 at open top 1220 of wind shield 1200, tabs 1270 being formed by a series of parallel cuts 1280 in body 1210 (best seen in Fig. 13A) extending from the top of cylindrical body 1210 in a direction parallel to the principal axis of the cylinder.

At the other end of body 1210 adjacent base 1230 is formed an opening 1260 to allow air access to a flame burning in wind shield 1200. Opening 1260 is dimensioned to permit access to the wick of a burner on which wind shield 1200 is placed so that the wick may be lit, for example by a match, spill, taper or gas-lighter.

Tabs 1270 are bendable. Fig. 13A shows wind shield 1200 with tabs 1270 in an unbent condition, whereby wind shield 1200 has its maximum height. In Fig. 13B, tabs 1270 are seen bent outwardly, thereby reducing the overall height of wind shield 1200.

In use, wind shield 1200 is placed over a flame burning at the top of a disposable fuel burner, such as a disposable fuel burner of the present invention, and rests with base 1230 on the top of the burner. Tabs 1270 are bent inwardly or outwardly, usually outwardly, to the extent necessary to permit the assembly of disposable fuel burner and wind shield 1200 to fit snugly in available space beneath a vessel which is to be heated by the disposable fuel burner. If necessary, wind shield 1200 is rotated so that opening 1260 is positioned away from the direction from which the wind is blowing, or from which draughts are coming. Thus, a flame burning on the disposable fuel burner is protected from the wind and draughts, but free admission of air to the flame is provided by opening 1260. In this way, a much greater proportion of available heat from the flame can be directed to heating the vessel above the burner, compared to a similar arrangement with no wind shield.

Figure 13D is an isometric view of an alternative wind shield in accordance with the invention, which is not equipped with height adjustment means. As seen in Figure 13D, wind shield 1240 is constructed from a metal can body and has an open top 1245 with body 1250 in the form of a cylinder. An opening is formed in base 1257 of can body 1250 to allow wind shield 1240 to be placed around the wick of a disposable fuel burner. In body 1250 adjacent base 1257 is formed an opening 1255 to allow air access to a flame burning in wind shield 1240. Opening 1255 is dimensioned to permit access to the wick of a burner on which shield 1240 is placed so that the wick may be lit.

Wind shield 1240 is also equipped with a plurality of supplementary air inlet holes 1242 which are, however, optional.

Wind shield 1240 is used in a similar way to wind shield 1200 seen in Figs. 13A to 13C, except that no height-adjustment of wind shield 1240 is possible.

Figures 13E and 13F are views of another wind shield in accordance with the invention. Figure 13E provides a plan view and Figure 13F provides a side elevation.

Referring to Figure 13E, wind shield 1260 is constructed of thin metal sheet and includes open top 1260 and open base 1266. Wind shield 1260 is substantially circular when seen in plan view - see Figure 13F - and the diameter of top 1265 is substantially larger than the diameter of base 1266. Wall 1268 curves upwardly and outwardly from its bottom to its top. Two openings 1275, 1276 are formed in wall 1268 at diametrically opposite positions extending from base 1266, to allow air access to a flame burning in wind shield 1260. Openings 1275, 1276 are dimensioned to permit

access to the wick of a burner on which wind shield 1260 is placed, so that the wick may be lit. Wind shield 1260 is also equipped with supplementary air holes 1272.

In use, wind shield 1260 is placed on a disposable fuel burner so as to surround the wick of the burner. By rotating wind shield 1260 if necessary, openings 1275, 1276 are positioned so that wind or draughts do not fall directly onto them, thereby protecting a flame burning at the wick from the wind or draughts.

Figure 14 is a diagrammatic cross-section through an eighth disposable fuel burner in accordance with the present invention. Referring to Figure 14, generally cylindrical disposable fuel burner 1300 consists of container 1305 having sides 1306 and closed bottom 1310, and holding liquid fuel 1330. Above the surface of fuel 1330 is wick support 1340 extending to sides 1306. Wick support 1340 includes well 1350 substantially in its centre, well 1350 having wick support opening 1360 formed therein.

Wick support 1340 also includes lip 1348 extending inwardly around the circumference of well 1350. The exposed end of wick 1370 passes through wick support opening 1360 and the other end of wick 1370 is immersed in fuel 1330. Wick support 1340 is equipped with air inlet opening 1355 in well 1350. Inner edge of lip 1348 is bent downwards towards the surface of well 1350, leaving clearance 1380 between the edge of lip 1348 and the surface of well 1350. Air inlet opening 1355 is located within space 1385 defined by lip 1348 and the surface of well 1350. Disposable fuel burner 1300 is also provided with weight 1345 secured to the underside of wick support 1340 and positioned substantially diametrically opposite air inlet opening 1355. It will be appreciated, however, that weight 1345 is optional.

Figure 15 is a diagrammatic cross-section through a ninth disposable fuel burner in accordance with the present invention. Referring to Figure 15, generally cylindrical disposable fuel burner 1400 consists of container 1405 having sides 1406 and closed bottom 1410, and holding liquid fuel 1430. Above the surface of fuel 1430 is wick support 1440 extending to sides 1406. Wick support 1440 has wick support opening 1460 formed therein, and is provided with air inlet opening 1455. The exposed end of wick 1470 passes through wick support opening 1460 and is somewhat flattened at that end. The other end of wick 1470 is immersed in fuel 1430. Disposable fuel burner 1400 is also equipped with top 1480 which acts as a fuel retaining means. Top 1480 and wick support 1440 are together seamed at seam 1445 to the upper edge of sides 1406. Space 1482 is defined between top 1480 and wick support 1440. Top 1480 has opening 1483 formed therein, and inner edges 1481 of top 1480 around opening 1483 are turned downwards towards wick support 1440. As seen in Figure 15, disposable fuel burner 1400 is in a condition for storage or transportation, and includes plug 1485 which is a press fit against edges 1481 of top 1480 into opening 1483. Peelable plastic seal 1486 is attached to top 1480 around opening 1483 and extends over plug 1485. It

will be appreciated that in other forms of the disposable fuel burner as illustrated in Figure 15, one or other of plastic seal 1486 and plug 1485 may be omitted. Disposable fuel burner 1400 is also equipped with a flame extinguishing means which takes the form of disk 1490 having a small hole 1497 therein near an edge of disk 1490, and pivoting about pin 1495 which passes through opening 1497 and is secured to top 1480.

In use, disk 1490 is pivoted about pin 1495 away from opening 1483. Peelable plastic seal 1486 and plug 1485 are removed, exposing an end of wick 1470 which may be pulled up to any desired height before being lit. If it is wished to adjust the height or intensity of a flame which burns at the exposed end of wick 1470, disk 1490 may be rotated so as partially to occlude opening 1483. If it desired to extinguish the flame, disk 1490 may be rotated so as to completely occlude opening 1483. It will be appreciated that if it is desired to utilise disk 1490 in this way, the height of wick 1470 must be adjusted so that it is not above the level of disk 1490.

Figure 16 is a diagrammatic cross-section through a tenth disposable fuel burner in accordance with the present invention. Referring to Figure 16, generally cylindrical disposable fuel burner 1500 consists of container 1505 having sides 1506 and closed bottom 1510 and holding liquid fuel 1530. Above the surface of fuel 1530 is wick support 1540 extending to sides 1506. Disposable fuel burner 1500 is also provided with top 1580 having opening 1583 therein. Fibreglass wick 1570 extends through wick support opening 1560 in wick support 1540 and the other end of wick 1570 is immersed in fuel 1530. Above the upper end of wick 1570 and secured between top 1580 and wick support 1540 is batt 1575 of terry-towelling material. Top 1580 and wick support 1540 are together seamed to an upper edge of sides 1506 of disposable fuel burner 1500.

In use, fuel 1530 saturates fibreglass wick 1570 as it is drawn by capillary action to the exposed end of wick 1570, thus saturating batt 1575 also because batt 1575 is in contact with wick 1570. A flame may then be lit in the exposed region of batt 1575 at opening 1583.

Figure 17A is a cross-section through a plug for use in a disposable fuel burner of the invention. Figure 17B is a diagrammatic cross-section of the plug illustrated in Figure 17A, inserted in an opening in the top of a disposable fuel burner of the invention. It will be appreciated, however, that the plug could be inserted in a well in a wick support, in the manner illustrated in Figure 6A. Figure 17C is a plan view from below of the plug illustrated in Figure 17A. As seen in Figs. 17A and 17C, for example, plug 1600 includes annular wall 1630 dimensioned to fit inside an opening in the top of a disposable fuel burner. Plug 1600 has a top 1610 which includes around its perimeter a stepped-in portion 1620. Annular wall 1630 is provided with two

diametrically opposed lugs 1640. As seen in Figure 17B, plug 1600 is adapted to be inserted in an opening in a top 1680 of a disposable fuel burner. The inner edge 1681 of the opening in top 1680 is turned downwards in the direction of a wick support (not shown) and when plug 1600 is inserted into the opening in disposable fuel burner top 1680, lugs 1640 engage against edge 1681 preventing pressure, such as from a wick pressing against the under surface of top 1610, from causing plug 1600 to lift from its position.

Lugs 1640 include a weakened portion (not shown) so that, when plug 1600 is removed from top 1680, such as by leverage from a fingernail inserted into stepped-in portion 1620, at least a portion of lugs 1640 breaks away, rendering plug 1600 easily removable from the opening in which it is positioned.

Figure 1 8A is a diagrammatic representation of a wick support for a disposable fuel burner of the invention, having valve means in the form of a piece of plastic film associated with the air inlet opening. Referring to Figure 18A there is seen from the underside wick support 1741 having wick support opening 1761 therein and including air inlet opening 1747. Covering air inlet opening 1747 is a piece of polyethylene film 1790 sealed to wick support 1741 by seal 1791. On side 1792 of film 1790 is not sealed to wick support 1741. When a disposable fuel burner including wick support 1741 is in use, air is admitted through air inlet opening 1747 and via unsealed side 1792 in seal 1791 to the interior of the disposable fuel burner's container. However, when the disposable fuel burner is inverted, fuel in the disposable fuel burner presses film 1790 against air inlet opening 1747 and against wick support 1741, and substantially prevents fuel in the disposable fuel burner from leaking through air inlet opening 1747.

Figures 1 8B to 1 8D illustrate diagrammatically alternative forms of valve means.

Figure 18B illustrates valve means including two layers of plastic film 1890, 1895, each sealed by seals 1891, 1896, respectively, to the underside of a wick support (not shown) and covering air inlet opening 1847 therein. Breaks 1892 and 1897 are provided in seals 1891 and 1896 respectively to provide a path for air admission to the interior of a disposable fuel burner. Break 1892 in seal 1891 of inner film 1890 is located remote from air inlet opening 1847.

Figure 18C illustrates a piece of polyethylene film 1990 sealed by seal 1991 to the underside of a wick support (not shown) and covering air inlet opening 1947 therein.

Slit 1993 is formed in a central portion of film 1990 at a location remote from air inlet opening 1947 to provide a path for air from air inlet opening 1947 to the interior of a disposable fuel burner equipped with the wick support.

Figure 1 8D similarly illustrates a piece of polyethylene film 2090 sealed by peripheral seal 2091 to the underside of a wick support (not shown) and covering air inlet opening 2047 formed therein. Two v-shaped slits 2093, 2094 are provided in film 2090 to provide an air path from air inlet opening 2047 to the interior of a disposable fuel burner equipped with the wick support.

Figures 1 8E and 1 8F each illustrate a rectangular piece of polyethylene film 2190 sealed by peripheral seal 2191 to the underside of a wick support (not shown) and covering air inlet opening 2147 therein. An aperture 2192 in peripheral seal 2191 is provided at an end of seal 2191 remote from air inlet opening 2147.

The disposable fuel burner of the present invention has a number of advantages in comparison to previously known disposable fuel burners. Some advantages of the disposable fuel burner of the present invention, which can be achieved without significant sacrifice to the fuel holding capacity of the disposable fuel burner of the invention compared to prior art disposable fuel burners, are as follows: (a) Inclusion of a well in the wick support of the disposable fuel burner of the first embodiment, or in the upper wick support of the disposable fuel burner of the second embodiment, means that the wick may be positioned at various heights above the opening in the wick support but still be somewhat shielded from winds and/or draughts by the sides of the container and the top, when present. Thus, the disposable fuel burner of the present invention is much more convenient to use in draughty or windy locations, compared to some previously known burners.

(b) It is difficult for fuel to be spilled from the burner of the second embodiment of the invention if it is accidentally knocked on to its side, as explained herein above.

(c) When the wick is located in a well in the wick support, the height of the flame produced by the disposable fuel burner of the invention can be adjusted within a wider range, to suit the requirements of the burner's applications, compared to some prior art burners. Thus, for example, this arrangement permits the use of larger wicks than in at least some prior art burners, providing larger or higher temperature flames and extending the applicability of the disposable fuel burner.

(d) Because the flame produced by the burner of the invention is localised to the position of the wick, rather than being spread over a wider layer of porous material, it need not come into contact with the material from which the burner container is made, and accordingly the body of the burner of the present invention only becomes mildly warm when the burner is in use, so that the burner may easily be picked up and moved to another location while it is alight, or immediately after the flame has been extinguished.

(e) Using a wick in accordance with the invention, the flame may be relit immediately it is extinguished, without adjustment of the wick, whereas in at least some prior art burners it is typically necessary to scrape the wick or porous material in contact with the wick (which can be difficult when the container is very hot) before the flame may be relit. In at least some of those prior art burners which include a layer of porous material in contact with a wick, there is a tendency for the porous material to be dislodged when it is scraped.

(f) Although the burner of the present invention is disposable, it may also be relatively easily refuelled when a previous charge of fuel has been consumed, simply by removing the wick and pouring fresh fuel through the wick support opening.

(g) The disposable fuel burner of the present invention is, at least in its simplest forms, easy and cheap to fabricate in comparison to some prior art disposable fuel burners. For example disposable fuel burners in accordance with the present invention may be fabricated from the components of a conventional food preservation can, and may be sealed using sealing machines used for food can sealing.

(h) Variations in the appearance of the disposable fuel burner may be made readily (for example the shape of the well, the shape and size of the wick support opening) for aesthetic appeal in particular applications.

(i) The disposable fuel burner of the invention may readily be sealed against leakage during transportation, using variety of possible convenient sealing means, whereas prior art burners are capable of being sealed by only one or two means.

(j) The disposable fuel burner of the invention typically has a greater fuel holding capacity than prior art disposable fuel burners which have a screw cap lid over the wick but which are of the same overall height and width.