GB2372313A - A portable gas heater - Google Patents

Abstract

A gas heating apparatus comprising a moulded housing 10 and a heat engine (22, fig.8) which is defined by an igniter, a gas regulator, a burner and gas feed controls, a recess 20 in the housing where the said engine is disposed which is constructed to include a thermal insulator 80 disposed between the periphery of the engine and the recess. Preferably the insulator is an air gap and the components of the heat engine are located on a tray-like member (24, fig.9). The said tray (24) is disposed in a vertical plane which also includes a plurality of lips (33', 33, fig.8), a protective gauze 26 located at the front face of the tray and a heat shield (90, fig.8) is located behind and spaced apart from the rear face of the tray. A base (64, fig.8) is connected by means to the lower edge of the tray for the purpose of a gas bottle seating location. Preferably the base is manufactured from cast aluminium and generally circular in shape. Castors/wheels 66, 68 support the base from the ground. A handle (36, fig.8) accessible from outside the housing 10 which has a hand grip portion 42. A removable rear cover 19 can also be attached to conceal the gas bottle. Preferably the housing is manufactured from plastics material such as polypropylene, polyurethane.

Description

DESCRIPTION GAS HEATING APPLIANCE The present invention relates to gas heating appliances and, in particular to portable gas heating appliances.

Existing portable gas heating appliances are known as cabinet heaters and comprise a box-like cabinet within which a bottle of pressurised gas is located, the bottle being connected to a gas supply regulator, gas feed controls, an igniter and one or more gas burners within the cabinet. The gas supply regulator, gas feed controls, igniter and gas bumer (s) form a so-called"heat engine".

The box-like cabinet of existing cabinet heaters is made from pressed sheet steel. As a result, the range of shapes which can readily be formed is limited and the cabinet tends to be relatively angular. Moreover, the use of pressed sheet steel restricts the range of colours and finishes which can be readily applied to the cabinet.

As a result, it has been difficult to design a portable gas heating appliance whose appearance departs radically from the general format of known heaters, yet which is still economic to produce.

In accordance with a first aspect of the present invention, a gas heating appliance comprises a moulded housing, a heat engine located in a recess in the housing and a thermal break between the periphery of the heat engine and the recess in which it is located.

By using a housing which is moulded rather than pressed, it is possible to vary the appearance to a much greater degree, in particular to include curves much more readily. Moreover, the use of a moulded plastics material allows a very wide range of colours and finishes to be selected for the housing. The provision of a thermal break between the heat engine and the recess in the housing around the whole periphery of the recess ensures that the moulded housing does not become too hot in use.

Preferably, the recess comprises an aperture within which the heat engine is located. Preferably, the thermal break comprises a gap between the periphery of the heat engine and the recess.

Preferably the heat engine comprises a convective heat engine. The advantage of a convective heat engine is that it reaches its working temperature much more quickly (typically in about one minute) than radiant plaque-type burners (which typically take approximately twelve minutes to reach optimum combustion).

Moreover, it is possible to vary the output of a convective heat engine infinitely between its minimum and maximum settings. In contrast, with a plaque-type heater the output is controlled by switching on or off one or more plaque heaters, each plaque being either completely lit or fully extinguished.

Preferably, the heat engine comprises a tray-like member. In use, the tray is preferably orientated in a generally upright position.

The tray-like member is preferably provided with one or more burners located towards its lower edge. These may conveniently be mounted on a manifold, which preferably is formed as an integral part of the tray-like member.

The tray-like member preferably comprises a lower generally planar portion and an upper generally planar portion inclined rearwardly with respect to the lower planar portion. In this way, as combustion products rise from the burner the transfer of heat to the tray-like member and therefore to the housing is significantly reduced. Preferably, the lower planar portion is orientated substantially vertically in use.

The tray-like member is preferably provided with a lip or rim around all or part of its periphery. Preferably, the lip extends beyond the upper edge of the housing aperture within which the heat engine is located, preferably by enlarging the portion of the lip in the region of the upper edge of the aperture. There may also be one or more second lips, extending from the surface of the tray-like member, located below the enlarged portion of the first lip. Preferably the or each second lip extends across (e. g. horizontally) the surface of the tray-like member. The provision of a second lip directs hot gases away from the upper periphery of the tray-like member and helps to reduce the transfer of heat to the housing.

The tray-like member may also be provided with one or more through apertures above the or each second lip. This allows air to flow from the rear of the tray-like member to the front and again assists in the reduction of heat transfer to the upper portion of the tray-like member and thence to the housing.

Preferably, the tray-like member is covered with a protective mesh or gauze. This prevents the tray-like member and the or each burner from being touched. Also, the mesh or gauze allows combustion products to escape freely from the heat engine whilst still remaining relatively cool to the touch.

Alternatively, however, the heat engine may comprise, for example, a plaque-type radiant burner, a"living flame"burner with a transparent front, a catalytic burner or other type of heat source.

The heating appliance preferably further comprises a base for supporting a fuel container (e. g. a gas cylinder). The base is preferably secured to the heat engine. In this way, the heat engine and the base can be secured together and then fitted into a housing, thereby facilitating assembly of the appliance.

Conveniently, the means for securing the base to the heat engine may comprise the spindle of a castor or wheel upon which the heating appliance rests in use. The castor is preferably releasably lockable, which assists in the loading of a fuel container onto the base.

The base preferably comprises a generally planar upper face for receipt of a fuel container. The base is also preferably circular in nature to correspond with the shape of a typical fuel container. The base may comprise one or more enclosing walls to retain the fuel container on the base in use.

The base may also be provided with locating means for more accurately locating a fuel container during loading of the container. For example, the base may comprise a recess in one edge which, when engaged by a fuel container, centres the fuel container with respect to the base. The guide means may comprise a generally lenticular recess, being part-circular and having a diameter which corresponds to that of a fuel container for use with the appliance.

The generally planar upper face of the base may be inclined rearwardly slightly (e. g. at 50 to the horizontal) to reduce the likelihood of the appliance tipping forwardly, particularly when the base supports a fuel container.

The appliance preferably further comprises a handle secured to, or forming part of, the heat engine and being accessible from outside the housing. A moulded housing is likely to be less robust than a conventional pressed steel casing and maneouvring of the heating appliance by means of the housing may increase the risk of damage to the appliance. By having a handle secured to, or forming part of, the heat engine, the risk of damage to the housing from maneouvring of the gas appliance is significantly reduced.

In accordance with a second aspect of the present invention, a gas heating appliance comprises a housing, a heat engine located in a recess in the housing and a handle connected to, or forming part of, the heat engine and being accessible from the exterior of the housing.

By providing a handle secured to or forming part of the heat engine the likelihood of damage to the housing is greatly reduced when the appliance is maneouvred by means of the handle.

Preferably, the heat engine is secured to a base upon which a fuel container rests in use. In this way, the handle is connected directly to the components which form the majority of the weight and/or strength of the appliance.

In accordance with a third aspect of the present invention, a gas heating appliance comprises an assembly of a heat engine and a base for receiving a fuel container and a housing mounted on the assembly, the housing having an aperture within which the heat engine is located.

This allows the heat engine to be secured to the base prior to enclosing the assembly within the housing and thus facilitates assembly of the appliance. Preferably, the assembly further comprises a handle which is accessible from the exterior of the housing.

In accordance with a fourth aspect of me present invention, a gas heating appliance comprises a housing and a heat engine located in an aperture in the housing, the heat engine comprising a generally upright tray member having one or more burners located towards the lower end of the tray.

Such an arrangement results in a heater which ensures thermal flow of the combustion products yet results in relatively low heat transfer from the combustion products to the tray and therefore to the appliance.

Preferably, the tray member comprises a lower planar portion and an upper planar portion inclined rearwardly with respect to the lower planar portion. This further assists in reducing the transfer of heat to the tray-like member and to the appliance.

Preferably, the tray-like member is provided with a lip or wall around all or part of its periphery. This helps to direct the flow of combustion products away from the edge of the aperture within which the heat engine is located and again assists in reducing the transfer of heat to the tray-like member and to the appliance.

Preferably, the lip or wall projects beyond the upper edge of the aperture within which the heat engine is located. This may be achieved by forming the lip into an extended lip or cowling in the region adjacent to the upper edge of the aperture in the housing.

In accordance with a fifth aspect of the present invention, a gas heating appliance comprises a substantially rigid support and a housing mounted on the support, the support comprising a handle accessible to the exterior of the housing.

By providing a handle on a rigid support, the housing of the appliance is much less prone to damage since the frame can be made very robustly. The rigid support also gives more freedom in the design of the housing, since it is not required to contribute substantially to the rigidity of the appliance.

Preferably, the appliance comprises a heat engine which forms part of the support.

By way of example only, a specific embodiment of the present invention will now be described, with reference to the accompanying drawings, in which: Fig. 1 is a perspective view of an embodiment of gas heating appliance in accordance with the present invention; Fig. 2 is a front view of the gas heating appliance of Fig. 1; Fig. 3 is a view from one side of the gas heating appliance of Fig. 1; Fig. 4 is a view from the other side of the gas heating appliance of Fig.

1; Fig. 5 is a plan view of the gas heating appliance of Fig. 1; Fig. 6 is an inverted plan view of the gas heating appliance of Fig. 1; Fig. 7 is a plan view of a burner tray forming part of the appliance of Fig. 1; Fig. 8 is a side view of an assembly of burner tray, base and handle forming part of the appliance of Fig. 1; Fig. 9 is a vertical cross-section through the burner tray of Fig. 7; and Fig. 10 is a perspective view of the handle forming part of the assembly of Fig. 8.

Referring firstly to Figs. 1 to 6, a gas heating appliance comprises a casing or housing 10 having two opposed side walls 12, a base wall 14, a top wall 16 and a front wall 18. However, the casing is an integral moulding of plastics material (e. g. polypropylene, polyurethane or any suitable plastics) and is rounded and thus the references to the walls are only given by way of guidance. The rear of the casing is enclosed by a removable rear wall 19.

The front wall 18 is provided with a large forwardly-facing aperture 20 of generally trapezoidal shape, having rounded comers and curved side walls, in which is located a complementarily-shaped heat engine 22. The heat engine 22 is a convective heat engine and comprises a burner tray 24 covered with a protective perforated metal gauze cover 26 Three air inlet apertures 25 are also provided in the front wall 18, beneath the aperture 20.

The burner tray 24 is cast from aluminium and as shown in Figs. 7 to 10 comprises a lower planar wall 28 which, in use, is arranged substantially vertically and an upper planar wall 30 inclined rearwardly to the first wall 28 at an angle of approximately 15 . An integrally cast upstanding lip 32 extends around the whole periphery of the tray 24 and at the upper end is formed into a more pronounced lip or cowling 33 which projects beyond the upper edge of the aperture 20 in the casing to direct heated gas out of the gas heating appliance, as will be explained. Air vents 34 are provided in the lip 32 on the lowermost edge of the tray.

A second lip or cowling 33'projects from the front face of a upper planar wall 30 of the tray, just below and generally parallel to the extended cowling 33 at the top of the tray. An elongate through aperture 34 is provided in the upper planar wall 30 of the tray between the upper and lower lips 33,33'.

The second lip 33'deflects much of the heated gas out of the appliance, even before it reaches the upper lip 33, which greatly reduces heat transfer to the portion of the upper wall 30 above the lower lip 33'. The aperture 34 in the wall 30 between the upper and lower lips 33, 33'also produces a flow of air from the rear of the tray to the front, which helps further in reducing heat transfer to the uppermost portions of the tray 24. Further additional lips 33', each pfererably associated with an aperture immediately above, may be provided.

A handle 36 fits onto mounting lugs 38 located on the rear face of the burner tray at its upper end. The handle comprises a main body 40 in the form of a right-angle shaped plate connected to a hand grip portion 42 which, as can be seen from the drawings, projects out of the casing rearwardly of the top wall 16 and thus is accessible to a user of the gas heating appliance. The vertical leg of the main body 40 of the handle is provided with four locating apertures 43 which each receive, in use, a respective one of the four integrally cast locating lugs 38 projecting from the rear face of the burner tray 24. The hand grip portion 42 is also provided with a mounting plate 45 which supports a valve assembly 46 which is accessible by means of a hinged cover 48 which can releasably close an access aperture 50 provided in the top wall 16 of the casing.

Two conventional elongate gas burners 52 are positioned parallel to one another, one in front of the other, at the lowermost end of the burner tray immediately above the air vents 34. The burners 52 are tube-shaped and extend horizontally in use from an integrally cast gas supply stub manifold 54 projecting from one side edge of the front face of the burner tray at its lowermost end. An aperture in the other ends of each of the two burners 52 is fitted onto a locating lug 55 projecting from the front face of the opposite edge of the burner tray.

The end of the burners 52 adjacent to the stub manifold 54 are each provided with two diametrically opposed primary aeration holes 56. Metal gauze 58 is located around the holes 56 on each burner to prevent back-burning and enhance flame stability.

The integrally cast stub manifold allows the number of burners to be varied as desired, simply by connecting the appropriate number of burners, from one upwards. This allows the appliance to be contructed in different variants having different heat outputs.

The burner tray is covered with the perforated metal gauze cover 26.

The metal gauze cover 26 comprises a peripheral frame 26'having a shape corresponding generally to that of the aperture 20 in the front wall of the housing, but allowing the upper lip 33 of the tray 24 to project beyond the uppermost edge of the frame 26'. The lowermost portion of the frame 26'is formed into a solid horizontal bar 27 which, when the gauze cover 26 is in position, is located immediately in front of the burners 52 and acts as a draught guard, and three aligned elongate air inlet apertures 29 immediately below the draught guard. A metal gauze sheet G is secured to the rear of the frame and extends over the main aperture formed by the frame 26'and over the air inlet apertures 29. The burner tray 24, the burners 52 and the gauze 26 form the convective heat engine 22.

It is also worth noting that the gauze G of the gauze cover and the finer metal gauze 58 surrounding the primary aeration holes of the burners 56 form a very efficient method of preventing any flame from reaching the exterior of the appliance and therby significantly increase the safety of the appliance as a whole.

It should also be noted that the burners are ocated in a volume which suurounded and defined by a front wall (the gauze cover 26), a rear wall (the burner tray 24) side walls (the side portions of the upstanding peripheral lip 32 of the tray 24) and an apertured base wall (the lowermost portion of the lip 32 of the base wall). The air flow to the burners can thus be metered more easily to an optimum level for combustion.

A heat shield 90 is also located behind the rear face of the burner tray 24 but spaced apart from it. As for the tray 24, the heat shield 90 comprises a planar lower wall 92, substantially parallel to the lower wall 28 of the tray 24, and an upper wall 94, substantially parallel to the upper wall 30 of the tray 24. The heat shield 90 not only reduces the amount of heat radiated to a gas container within the housing, but the heat shield 90 and the rear face of the tray 24 form a"chimney"through which air passes upwardly and out through the aperture 34 between the upper and lower lips 33, 33', thereby lowering the temperature of the tray and reducing heat transfer by conduction. The heat shield is mounted on the mounting lugs 38 of the tray 24.

A rectangular mounting plate 60 projects from the foot of the burner tray 24 beyond the lowermost edge of the burner tray. The lowermost edge of the mounting plate is provided with a rearwardly directed mounting lug 62 at each end. The burner tray is connected by means of the mounting plate to a cast aluminium base 64 upon whose upper face, in use, a conventional gas cylinder rests. The base 64 is supported by two front castors 66 and two rear castors 68. At least one of the rear castors is of the locking type, whereby the castor can be locked by actuation of a footactuated locking lever. The spindle 70 of each of the front castors 66 passes through an aperture 72 in the base wall of the casing through a respective aperture 73 in the base of the burner tray and into an aligned aperture 74 in a respective one of the two mounting lugs 62 of the mounting plate 60, thereby securing the burner tray 24 to the base 64. The castors 66,68 are connected to the base in such a manner that when the base is supported on the castors the upper face of the base is inclined rearwardly at approximately 50 to the horizontal.

The base 64 assumes the shape of a generally circular flat disc but, as seen in Fig. 6, the rearmost edge of the base is provided with a lenticular recess 76, forming a part-circular locating edge for locating a fuel container with respect to the base, as will be explained. An upstanding retaining wall 78 extends around the edge of the base 64 from each end of the recess to the mounting lugs 62 of the mounting plate 60. Several holes 79 are also cast into the base, both o reduce its weight and to increase the circulation of air through the base in order to reduce the amount of heat transferred to a gas container supported on the upper surface of the base.

The base is formed from two substantially semi-circular portions hinged about a hinge H whose axis extends horizontally and transversely. The hinge can be locked in position to retain the base in a generally circular configuration (as illustrated) or can be unlocked in order to allow the rear portion of the base to be hinged upwardly. This reduces the size of the appliance and is particularly useful if the appliance is to be hung on a wall (without the rear cover 19) from storage and when the heat engine/base sub-assembly is transported before being assembled with the housing to form the assembled appliance.

It will be observed that a gap 80 exists between the periphery of the heat engine 22 and the edge of the aperture 20 in the front wall 18 of the casing 10, around the entire periphery of the aperture.

In order to construct the gas heating appliance, the two elongate gas burners 52 are first located in position on the gas supply stub manifold 54 and the locating lug 56 projecting from the front face of the burner tray 24. The metal gauze cover 26 is then fixed in position over the front face of the burner tray 24. In the illustrated embodiment the cover 26 is mounted by means of bolts. Alternatively, however, the cover 26 may be hingedly mounted to the tray 24 towards it upper end or its lower end. The heat shield 90 and the handle assembly are located on the locating lugs 38 projecting from the rear face the burner tray 24 and bolted in position. The assembled heat engine is then positioned on the base 64 and is secured to the base in a generally upright position by means of two bolts 81, each passing through the base 64 into a respective one of the two mounting lugs of the mounting plate 60 projecting below the bottom edge of the burner tray 24.

The assembled heat engine 22, handle 36 and base 64 is then fitted into the moulded housing 10 as previously described, whereupon the heat engine 22 is located in the aperture 20 in the front wall 18 of the appliance, with a thermal break, formed by a peripheral gap 80, extending between the heat engine and the edge of the aperture 20. The heat engine 22 is then secured in position with respect to the housing by attaching the front castors 66, the spindle 70 of each castor passing through the aperture 72 in the base wall 14 of the housing, through an aperture 73 in the base 64 and into an aperture 74 in a respective one of the two mounting lugs 62 of the mounting plate 60. The heat engine 22 is thereby secured in position with respect to the housing. The handle 36 is accessible from outside the housing, since it projects beyond the rearmost edge of the top wall 16 of the housing.

A conventional container of fuel is then placed on the base 64. This is achieved by locking the or each lockable rear castor 68 and moving the container into contact with the lenticular recess 76 in the rearmost edge of the base, which is of a size and shape corresponding to the exterior of the container. Thus, by engaging the container with the recess 76 the container is accurately centred with respect to the base and need only then be lifted onto the base over the retaining walls 78. The locked rear castors 68 retain the appliance in place during loading of the container. The container is then connected to the control valve assembly 46 by means of conventional tubing (not illustrated). The rear cover 19 is then lifted into place over the exposed rear portion of the gas container and secured in position over the rear of the housing.

The gas appliance may be moved to the desired location by means of the castors 66,68 and by means of the handle 36. By securing the handle 36 directly to the heat engine 22, the risk of damage to the housing 10 of the appliance is significantly reduced since the temptation for a user to manoeuvre the appliance by gripping a portion of the housing is greatly reduced by the presence of the readily accessible handle. By arranging the upper face of the base 64 to be inclined rearwardly at approximately 5 to the horizontal, the tendency for the appliance to tip forwardly is greatly reduced.

The appliance is turned on and controlled by means of the regulating valve 46 which is accessed by opening the hinged cover 48, whereupon gas is fed to the two burner tubes 52 and ignited. Air heated by the burners passes upwardly and out through the metal gauze G. By inclining the upper planar wall 30 of the burner tray 24 rearwardly with respect to the lower planar wall 28, the transfer of heat from the burners to the burner tray is greatly reduced. The extended upper metal lip or cowlings 33 at the top of the burner tray, which projects beyond the uppermost edge of the aperture 20 in the front wall 18 of the housing, and the lower lip 33'also ensure that heated air from the burners is directed around and away from the upper edge of the aperture, thereby significantly reducing the amount of heat transferred to the housing.

As the burners 52 bum the fuel, air for combustion is drawn through the air inlets 25 in the front of the housing and through the air vents 34 in the lowermost part of the lip of the burner tray 24. Combustion air is also drawn in through the apertures 29 at the foot of the gauze cover 26. Air drawn in through the air inlets 25 also passes upwardly through the gap of"chimney"formed between the rear of the tray 24 and the heat shield 90, and passes out through the aperture 34 between the upper and lower lips 33, 33'projecting from the burner tray 24.

The flow of air over the front and rear surfaces of the tray 24 and the guiding of the heated gases by the upper and lower projecting lips 33, 33'controls the transfer of heat to the housing and to the gas container within the housing. Moreover, the provision of a thermal break in the form of a gap around the entire periphery of the burner tray between the burner tray and the edge of the aperture 20 significantly reduces the amount of heat transferred from the burner tray to the housing.

The invention is not restricted to the details of the foregoing embodiment. For example, in view of the fact that the burner tray is cast, it would be possible to cast the gasways integrally into the tray. It would also be possible to cast a substantial portion of the burner elements integrally into the tray, particularly if surface combustion plaque burners are used. Not only would this result in a cost saving, but it would also reduce the likelihood of damage of the gasways as compared with the use of external pipework which can be knocked in use.

Furthermore, the outer surface of the burner tray may be profiled to provide an increased surface area for radiant heat production. This could be achieved, for example, by forming the surface of the tray into a series of dimples, inverse dimples, ribs or other projections and/or recesses. The desired shape can easily and conveniently be cast into the surface of the tray.

There may also be a temperature sensor adapted to detect the temperature of at least a portion of the housing (e. g. at the uppermost edge of the aperture) to ensure that it does not become too hot in use. This is preferably connected to a cut-out device for the heat engine. There may also be a tilt switch and/or a carbon monoxide sensor and/or an oxygen depletion sensor connected to a cut-out device. If more than one such switch or sensor is used, then preferably the same cut-out device is responsive to signals from each such switch or sensor.

The appliance may further comprise a timer or clock which may detect the time for which the appliance has been operated. This can be used to give an indication of the total amount of fuel consumed and therefore the total amount of fuel remaining.

Claims (89)

1. A gas heating appliance comprising a moulded housing, a heat engine located in a recess in the housing and a thermal break between the periphery of the heat engine and the recess in which it is located.

2. A gas heating appliance as claimed in claim 1, wherein the recess comprises an aperture within which the heat engine is located.

3. A gas heating appliance as claimed in claim 1 or claim 2, wherein the thermal break comprises a gap between the periphery of the heat engine and the recess.

4. A gas heating apparatus as claimed in any of claims 1 to 3, wherein the heat engine comprises a convective heat engine.

5. A gas heating apparatus as claimed in claim 4, wherein the heat engine comprises a tray-like member.

6. A gas heating apparatus as claimed in claim 5, wherein the tray is orientated in a generally upright position.

7. A gas heating apparatus as claimed in claim 6 or claim 7, wherein the heat engine further comprises one or more burners.

8. A gas heating apparatus as claimed in claim 7, wherein the or each burner is located towards or adjacent to the lower edge of the tray-like member.

9. A gas heating apparatus as claimed in claim 7 or claim 8, wherein the or each burner is mounted on a manifold.

10. A gas heating apparatus as claimed in claim 9, wherein the manifold is formed as an integral part of the tray-like member.

11. A gas heating apparatus as claimed in any of claims 5 to 10, wherein the tray-like member comprises a lower generally planar portion and an upper generally planar portion inclined rearwardly with respect to the lower planar portion.

12. A gas heating apparatus as claimed in claim 11, wherein the lower generally planar portion is orientated substantially vertically.

13. A gas heating apparatus as claimed in any of claims 5 to 12, wherein the tray-like member is provided with a lip around all or part of its periphery.

14. A gas heating apparatus as claimed in claim 13, wherein the lip extends beyond the upper edge of the housing aperture within which the heat engine is located.

15. A gas heating apparatus as claimed in claim 14, wherein the lip is enlarged in the region where it extends beyond the upper edge of the housing aperture.

16. A gas heating apparatus as claimed in claim 14 or claim 15, further comprising one or more further lips, extending from the surface of the tray-like member and located below the lip which extends beyond the upper edge of the housing aperture.

17. A gas heating apparatus as claimed in claim 16, wherein the or each further lip extends across the surface of the tray-like member.

18. A gas heating apparatus as claimed in claim 16 or claim 17, further comprising one or more through apertures in the tray-like member above the or each further lip.

19. A gas heating apparatus as claimed in any of the preceding claims, further comprising a protective mesh or gauze covering the heat engine.

20. A gas heating apparatus as claimed in any of the preceding claims, further comprising a base for supporting a fuel container.

21. A gas heating apparatus as claimed in claim 20, wherein the base is secured to the heat engine.

22. A gas heating apparatus as claimed in claim 21, wherein the means for securing the base to the heat engine comprises the spindle of a castor or wheel.

23. A gas heating apparatus as claimed in any of claims 20 to 22, wherein the base comprises a generally planar upper face for receipt of a fuel container.

24. A gas heating apparatus as claimed in claim 23, wherein the upper face is inclined rearwardly.

25. A gas heating apparatus as claimed in any of claims 20 to 24, wherein the base is generally circular.

26. A gas heating apparatus as claimed in any of claims 20 to 25, wherein the base comprises locating means for locating a fuel container.

27. A gas heating apparatus as claimed in claim 26, wherein the locating means comprises a recess in an edge of the base.

28. A gas heating apparatus as claimed in any of claims 1 to 27, further comprising a handle secured to, or forming part of, the heat engine and being accessible from outside the housing.

29. A gas heating apparatus comprising a housing, a heat engine located in a recess in the housing and a handle connected to, or forming part of, the heat engine and being accessible from the exterior of the housing.

30. A gas heating apparatus as claimed in claim 29, wherein the heat engine comprises a tray-like member and one or more burners, the handle extending from the tray-like member.

31. A gas heating apparatus as claimed in claim 30, wherein the handle is formed separately from the tray-like member and subsequently attached thereto.

32. A gas heating apparatus as claimed in claim 31, wherein the handle is attached to a rear face of the tray-like member.

33. A gas heating apparatus as claimed in claim 32, wherein the tray-like member comprises integrally formed attachment means on a rear face of the tray-like member.

34. A gas heating apparatus as claimed in claim 33, wherein the handle comprises complementarily shaped attachment means for engagement with the attachment means on the tray-like member.

35. A gas heating apparatus as claimed in claim 33 or claim 34, wherein the integrally formed attachment means comprise one or more projections.

36. A gas heating apparatus as claimed in any of claims 29 to 35, further comprising a base for receipt of a fuel container, the heat engine being secured to the base.

37. A gas heating apparatus as claimed in claim 36, wherein the means for securing the base to the heat engine comprises the spindle of a castor or wheel.

38. A gas heating apparatus as claimed in claim 36 or claim 37, wherein the base comprises a generally planar upper face for receipt of a fuel container.

39. A gas heating apparatus as claimed in claim 38 wherein the upper face is inclined rearwardly.

40. A gas heating apparatus as claimed in any of claims 36 to 39, wherein the base is generally circular.

41. A gas heating apparatus as claimed in any of claims 36 to 40, wherein the base comprises locating means for locating a fuel container.

42. A gas heating apparatus as claimed in claim 41, wherein the locating means comprises a recess in the edge of the base.

43. A gas heating appliance comprising an assembly of a heat engine and a base for a receiving fuel container and a housing mounted on the assembly, the housing having an aperture within which the heat engine is located.

44. A gas heating appliance as claimed in claim 43, wherein the assembly further comprises a handle which is accessible from the exterior of the housing.

45. A gas heating apparatus as claimed in claim 44, wherein the heat engine comprises a tray-like member and one or more burners, the handle extending from the tray-like member.

46. A gas heating apparatus as claimed in claim 45, wherein the handle is formed separately from the tray-like member and subsequently attached thereto.

47. A gas heating apparatus as claimed in claim 46, wherein the handle is attached to a rear face of the tray-like member.

48. A gas heating apparatus as claimed in claim 47, wherein the tray-like member comprises integrally formed attachment means on a rear face of the tray-like member.

49. A gas heating apparatus as claimed in claim 48, wherein the handle comprises complementarily shaped attachment means for engagement with the attachment means on the tray-like member.

50. A gas heating apparatus as claimed in claim 48 or claim 49, wherein the integrally formed attachment means comprise one or more projections.

51. A gas heating appliance comprising a housing and a heat engine located in an aperture in the housing, the heat engine comprising a generally upright tray member having one or more burners located towards the lower end of the tray.

52. A gas heating apparatus as claimed in claim 51, wherein the or each burner is mounted on a manifold.

53. A gas heating apparatus as claimed in claim 52, wherein the manifold is formed as an integral part of the tray-like member.

54. A gas heating apparatus as claimed in any of claims 51 to 53, wherein the tray-like member comprises a lower generally planar portion and an upper generally planar portion inclined rearwardly with respect to the lower planar portion.

55. A gas heating apparatus as claimed in claim 54, wherein the lower generally planar portion is orientated substantially vertically.

56. A gas heating apparatus as claimed in any of claims 51 to 55, wherein the tray-like member is provided with a lip around all or part of its periphery.

57. A gas heating apparatus as claimed in claim 56, wherein the lip extends beyond the upper edge of the housing aperture within which the heat engine is located.

58. A gas heating apparatus as claimed in claim 57, wherein the lip is enlarged in the region where it extends beyond the upper edge of the housing aperture.

59. A gas heating apparatus as claimed in claim 57 or claim 58, further comprising one or more further lips, extending from the surface of the tray-like member and located below the lip which extends beyond the upper edge of the housing aperture.

60. A gas heating apparatus as claimed in claim 59, wherein the or each further lip extends across the surface of the tray-like member.

61. A gas heating apparatus as claimed in claim 59 or claim 60, further comprising one or more through apertures in the tray-like member above the or each further lip.

62. A gas heating apparatus as claimed in any of claims 51 to 61, further comprising a protective mesh or gauze covering the heat engine.

63. A gas heating apparatus as claimed in any of claims 51 to 62, further comprising a base for supporting a fuel container.

64. A gas heating apparatus as claimed in claim 63, wherein the base is secured to the heat engine.

65. A gas heating apparatus as claimed in claim 64, wherein the means for securing the base to the heat engine comprises the spindle of a castor or wheel.

66. A gas heating apparatus as claimed in any of claims 63 to 65, wherein the base comprises a generally planar upper face for receipt of a fuel container.

67. A gas heating apparatus as claimed in claim 66, wherein the upper face is inclined rearwardly.

68. A gas heating apparatus as claimed in any of claims 63 to 67, wherein the base is generally circular.

69. A gas heating apparatus as claimed in any of claims 63 to 68, wherein the base comprises locating means for locating a fuel container.

70. A gas heating apparatus as claimed in claim 69, wherein the locating means comprises a recess in an edge of the base.

71. A gas heating apparatus as claimed in any of claims 51 to 70, further comprising a handle secured to, or forming part of, the heat engine and being accessible from outside the housing.

72. A gas heating appliance comprising a substantially rigid support and a housing mounted on the support, the support comprising a handle accessible to the exterior of the housing.

73. A gas heating appliance as claimed in claim 72, wherein the support comprises a heat engine.

74. A gas heating appliance as claimed in claim 73, wherein the heat engine is located in a recess in the housing.

75. A gas heating appliance as claimed in claim 73 or claim 74, wherein the handle is connected to the heat engine.

76. A gas heating apparatus as claimed in any of claims 73 to 75, wherein the heat engine comprises a tray-like member and one or more burners, the handle extending from the tray-like member.

77. A gas heating apparatus as claimed in claim 76, wherein the handle is formed separately from the tray-like member and subsequently attached thereto.

78. A gas heating apparatus as claimed in claim 77, wherein the handle is attached to a rear face of the tray-like member.

79. A gas heating apparatus as claimed in claim 78, wherein the tray-like member comprises integrally formed attachment means on a rear face of the tray-like member.

80. A gas heating apparatus as claimed in claim 79, wherein the handle comprises complementarily shaped attachment means for engagement with the attachment means on the tray-like member.

81. A gas heating apparatus as claimed in claim 79 or claim 80, wherein the integrally formed attachment means comprise one or more projections.

82. A gas heating apparatus as claimed in any of claims 73 to 81, further comprising a base for receipt of a fuel container, the heat engine being secured to the base.

83. A gas heating apparatus as claimed in claim 82, wherein the means for securing the base to the heat engine comprises the spindle of a castor or wheel.

84. A gas heating apparatus as claimed in claim 82 or claim 83, wherein the base comprises a generally planar upper face for receipt of a fuel container.

85. A gas heating apparatus as claimed in claim 84 wherein the upper face is inclined rearwardly.

86. A gas heating apparatus as claimed in any of claims 82 to 85, wherein the base is generally circular.

87. A gas heating apparatus as claimed in any of claims 82 to 86, wherein the base comprises locating means for locating a fuel container.

88. A gas heating apparatus as claimed in claim 87, wherein the locating means comprises a recess in the edge of the base.

89. A gas heating apparatus substantially as herein described with reference to and as illustrated in the accompanying drawings.