GB2473560A

GB2473560A - Portable stove base that can also insulate a receptacle bottom

Info

Publication number: GB2473560A
Application number: GB1020819A
Authority: GB
Inventors: Thomas Barry Jenkins
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-12-08
Filing date: 2010-12-08
Publication date: 2011-03-16
Anticipated expiration: 2030-12-08
Also published as: GB201020819D0; GB2473560B

Abstract

A portable stove 1 has a ground-engaging base 17 of thermally insulating material that can either engage the bottom of a gas canister 12, or can engage with the bottom of a receptacle (2, fig 6) when the contents have been heated to minimise the loss of heat through a bottom wall 23 of the receptacle 2. The receptacle bottom wall 23 is thermally conductive (e.g copper with ribs 24), while side walls are less conductive or insulated (e.g. steel). The gas canister 12 is connected by a gas supply conduit 5 to a gas burner 3 which is surrounded by a bowl shaped windshield 7. The windshield positively engages and supports the lower part of a receptacle 2, thus forming a chamber in which the burner 3 is located to minimise the loss of heat. An alternative form of windshield (figs 5-7) and a thermometer can be provided; the stove may also burn liquid or solid fuel; and the parts can nest together when packed.

Description

A Portable Stove

This invention relates to a portable stove, of the type used by the military, or by adventurous campers who carry all of their equipment in a rucksack. Of course, such stoves may also be used in other situations. In particular this invention relates to a portable cooking stove and cooking receptacle combination.

The preferred stoves of the invention may be used for cooking food, or for heating water to make a beverage such as tea or coffee, or for heating food that has been pre-cooked, and for re-constituting dehydrated food.

It is believed that preferred stoves in accordance with the invention will be very thermally efficient, thus minimising the use of gas, and consequently minimising the carbon footprint of the stove.

According to this invention there is provided a portable stove and receptacle combination, wherein the stove comprises a gas burner, a supply conduit to supply gas to the burner, the supply conduit having a connector to connect the supply conduit to a gas cartridge, and a support arrangement to support the receptacle above the burner; the receptacle having a bottom wall and a side wall, the bottom wall having relatively high thermal conductivity, and the sidewall having relatively low thermal conductivity; the combination further comprising a base of thermally insulating material, the base being configured to be connected to the bottom of the stove to provide stability for the stove, and also to be connected to the bottom of the receptacle to provide thermal insulation for the bottom wall of the receptacle.

It is envisaged that when the stove is in use, the base will be connected to the bottom of the stove to provide the stove with stability. Typically the gas canisters used with such stoves do not have a large diameter, and so the stoves can be unstable. The base may be designed to provide enhanced stability for the stove. However, when the stove has been used, and the contents of the receptacle are hot, the base may be transferred to the receptacle, thus providing thermal insulation for the bottom wall of the receptacle, and helping to maintain the temperature of the contents of the receptacle. This will reduce the need to re-heat the contents of the receptacle.

Preferably, the support arrangement is a windshield, the windshield being directly connectable to the receptacle with a positive connection, the bottom wall of the receptacle and the windshield together forming a chamber surrounding the gas burner, there being apertures to enable air to reach the burner, and to permit exhaust gas to escape from the chamber. The apertures may be formed in the windshield.

The presence of a positive connection between the receptacle and the support arrangement will help minimise the risk of the receptacle slipping off the stove if the stove should tilt. The chamber defined by the bottom wall of the receptacle will totally contain the flame of the gas burner. This will minimise the risk of the flame blowing out, and also minimise the amount of heat wasted by convection or radiation. All of the heat of the flame will be directed onto the bottom of the receptacle.

Conveniently, the windshield is configured to contain liquid fuel or solid fuel.

In this way, should the gas supply become exhausted, the stove may still be used if any solid or liquid fuel is available.

Advantageously, the bottom wall of the receptacle is dome shaped, and the windshield has a complementary bowl shape, so that the windshield, when inverted, can be accommodated within the dome shaped bottom wall of the receptacle.

The dome shape of the bottom wall of the receptacle may improve the heat transfer properties of the bottom wall. The fact that the windshield can be accommodated within the dome means that the stove can be packed into a very small space when it is dismantled.

The stove may be supplied without a gas cartridge, but preferably, when initially supplied, the stove will incorporate a gas cartridge, the bottom of the gas cartridge constituting the bottom of the stove, when the stove is ready for use.

In one embodiment of the invention the bottom wall of the gas cartridge is dome shaped, and the windshield has a complementary bowl shape, so that the windshield, when inverted, can be accommodated within the dome shaped bottom wall of the gas cartridge.

In this embodiment the windshield can be stored in the bottom part of the gas cartridge when the stove is dismantled.

In a preferred embodiment in which the windshield is configured to contain liquid the! or solid fuel, the base is provided with a complementary connection to engage securely with the connector of the gas supply conduit.

In such an embodiment the gas supply conduit can be secured directly to the base, with the windshield and burner then being located directly above the base, the gas cartridge being omitted. This will enable the stove to be used with liquid or solid fuel with enhanced stability.

Preferably the receptacle has a lid of thermally insulating material, the lid having a recess to accommodate at least one component of the stove.

The lid will help maintain the temperature of the contents of the receptacle, and a component of the stove may be stored in the lid, again saving space, when the stove is dismantled.

In one embodiment of the invention the gas cartridge is dimensioned to be received within the receptacle. This will further minimise the space occupied by the stove when it is dismantled.

Conveniently, the bottom wall of the receptacle is provided with ribs or fms to aid the transfer of heat from the flame to the contents of the receptacle.

Advantageously, the base is provided with a plurality of ground-engaging teeth.

The teeth may be pressed into the ground to enhance the stability of the stove and receptacle combination when in use.

Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which: FIGURE 1 is a sectional view of a first embodiment of a portable stove and receptacle combination assembled and ready for use.

FIGURE 2 is a cut away perspective view of the combination of Figure 1, FIGURE 3 is a sectional view of the embodiment of Figures 1 and 2 when the stove is dismantled, FIGURE 4 is a cut away perspective view of the first embodiment as shown in Figure 3, FIGURE 5 is a sectional view of a second embodiment of the invention, with the portable stove and receptacle combination assembled and ready for use, FIGURE 6 is a sectional view of the embodiment of Figure 5 with the stove dismantled and the gas cartridge removed, and FIGURE 7 is a sectional view of some of the components of the embodiment of Figures 5 and 6 ready for use with a solid or liquid fuel.

Referring initially to Figures 1 and 2 a first embodiment of the invention is a portable cooking stove 1 and receptacle 2 combination. The stove is a lightweight stove as may be used by the military, or by campers who carry all of their equipment in a rucksack. Ideally, therefore, the stove should be light, and should be capable of being packed neatly in a rucksack in the minimum of space. Also the stove should be thermally efficient, to minimise the amount of gas that has to be carried.

The stove 1 comprises a gas burner 3. The gas burner 3 has a plurality of small apertures through which gas emerges when the stove is in use. The gas burner 3 is screwed in a gas-tight manner to the upper end of a bore 4 through a rigid gas supply conduit 5. The gas supply conduit S includes a control valve (not shown), the operating handle 6 of which can be seen in Figures 3 and 4. There may be small air inlet holes in the gas supply conduit to enable some air to be entrained with the gas before the gas reaches the burner 3 when the stove is in use.

The lower end of the gas supply conduit 5 is provided with a connector to connect the supply conduit to a gas canister 12. In this embodiment the connector is an enlarged diameter threaded part of the bore 4 passing through the conduit.

A windshield 7 is provided. The windshield is of a bowl shape, having a curved lower part 8 extending up to a vertical sidewall 9. The top of the sidewall 9 is provided with castellations 10 (see particularly figures 3 and 4). The central region of the lower part of the bowl is raised, with the raised part being secured to the burner 3 (or simply being trapped between the burner 3 and the gas supply conduit 5 as the burner 3 is screwed into place) so that, when the stove is ready for use, the windshield 7 surrounds the burner 3. A plurality of apertures 31 are provided in the upper part of the windshield.

It is to be noted that the windshield 7 forms an annular trough 11 which surrounds the gas supply conduit 5 and the burner 3, with the apertures 31 being located above the trough.

As shown in Figures 1 and 2 a cylindrical gas cartridge 12 is provided. The gas cartridge 12 has a dome shaped bottom wall 13, and a cylindrical side wall 14 which merges into a top wall 15. At the centre of the top wall 15 is a connection 16 which is designed to co-operate with the connector formed by the enlarged diameter part of the bore 4 of the gas supply conduit 5. The lower part of the gas supply conduit is screwed to a threaded stub that forms part of the connection 16 on the gas cartridge 12. This firmly connects the gas supply conduitS to the gas cartridge 12, and also open a valve contained within the connection 16 in the gas cartridge to enable the flow of gas. A connection of this type is well known in the art.

A base 17 is mounted on the bottom of the gas cartridge 12, which constitutes the bottom of the cooker 1. The base is made of a thermally insulating material, such as a plastic material. The base is circular, having a peripheral upstanding sidewall 18. The sidewall 18 is provided with a plurality of resilient snap fmgers 19 which can engage a bead at the base of the sidewall 14 of the gas cartridge 12, thus connecting the base 17 to the bottom of the cooker. The base has a membrane 20 extending across the space surrounded by the sidewall, and in the centre of the membrane there is an upstanding threaded stud 21 which has the same dimensions as the threaded stub provided in the connection 16 of the gas cartridge 12.

The lowennost part of the sidewall 18 of the base is provided with depending triangular ground engaging teeth 22.

Mounted on the stove 1 is the receptacle 2, which is of cylindrical form, being of the same diameter as the gas cartridge 12. The receptacle has a circular dome shaped bottom wall 23 which is formed of a material with a high thermal conductivity, such as copper. The bottom wall 23 is provided a plurality of radially extending ribs 24. The ribs serve to reinforce the bottom wall 23, enabling the bottom wall to be made of a thin sheet of material while still having sufficient strength, which will improve the heat transfer properties of the bottom wall. The ribs also serve to increase the total surface area of the bottom wall, thus further improving the heat transfer properties of the lower wall. The use of a thin sheet also minimises the amount of copper used, and also helps to keep the overall weight to a minimum.

The periphery of the bottom wall 23 is connected to a cylindrical sidewall 25, for example by crimping or TIG welding. The sidewall is made to have thermal insulating properties. The sidewall may simpiy be made of stainless steel, which, compared with copper, has a relatively low thermal conductivity.

However, as discussed below, the sidewall may be formed of other materials, or in other ways, to enhance the thermal insulation properties of the sidewall.

The receptacle 2 may be provided with a handle. The receptacle may thus be in the form of a saucepan, or may be in the form of a drinking mug.

The receptacle 2 has a lid 26 made of a thermally insulating material, such as a plastic material. The lid 26 is provided with a through-hole 27 through which the contents of the receptacle can be drunk while the lid 26 is in place, and also has a recess 28 which is complementary to the shape of the supply conduit 5.

When the stove is to be used the base 17 is connected to the lower part of the gas cartridge 12, and the gas supply conduit 5 is connected to the connection 16 of the gas cartridge 12. The teeth 22 maybe pressed firmly into the ground to enhance the stability of the stove. The gas burner 3 and the windshield 7 are screwed into place at the top of the gas supply conduit 5. The receptacle is then put in position, supported by the top of the windshield 7. It is to be noted that the configuration of the castellations 10 on the top of the windshield are complementary to the form of the radial ribs 24 at the periphery of the bottom wall 23 of the receptacle 2. The castellations 10 thus engage with the ribs and prevent rotation of the receptacle 2 relative to the stove 1. Also, because of the dome form of the bottom wall 23, the uppermost edge of the sidewall 9 of the windshield 7 extends up into the lower part of the receptacle, and thus there is a positive engagement between the stove 1 and the receptacle 2 which will prevent the receptacle sliding off the stove 1 should the stove tilt.

In order to heat the contents of the receptacle the operating handle 6 (figure 3) of the gas control valve is turned, and the gas (or gas/air mixture) then emerging from the apertures of the gas burner 3 is lit, and immediately the receptacle is put into position on the support constituted by the windshield 7. A closed chamber is thus created between the receptacle and the windshield. Air may enter this chamber, and exhaust gas may exit the chamber, through the apertures 31. The closed chamber will contain the flame from the burner. It is envisaged that there will be a minimal wastage of heat, as all of the heat will pass to the receptacle. Even radiant heat initially absorbed by the windshield 7 will pass, by conduction, to the receptacle 2.

The diameter of the receptacle 2, in this embodiment, is the same as the diameter of the gas cartridge 12. When the contents of the receptacle 2 have been heated to a sufficient temperature, the receptacle 2 may be removed from the stove 1, and the base 17 may be removed from the bottom of the gas cartridge 12, and may then be snapped into place on the bottom of the receptacle 2. This will provide thennal insulation for the bottom of the receptacle 2, minimising heat loss through the excellent heat conductor forming the bottom wall 23 of the receptacle. This may be of crucial importance if the stove is being used in snowy conditions, and the receptacle is to be placed on the ground.

When the stove 1 is dismantled, as shown in Figures 3 and 4, with the gas flow conduit 5 being separated from the gas cartridge 12, and from the gas burner 3 and windshield 7, the components of the stove can be packed away in a minimum space. The windshield 7 may be inverted and received within the recess formed by the domed bottom wall 13 of the gas cartridge 12, being held in place by the base 17 that is snapped into position. The gas supply conduit 5 may be stored in the recess 28 provided in the lid 26. Thus the stove may be packed away neatly, taking up the minimum of space.

Figures 5 to 7 illustrate a second embodiment of the invention, which in some respects is identical to the first embodiment. In the stove 1' the gas cartridge 12 and the base 17 are the same as in Figures 1 to 4. The receptacle 2 is also the same.

The gas supply conduit 5' is shorter than in the first embodiment, but still has a connector at the lower end of the bore 4 to engage with the connection 16 of the gas cartridge 12, and an operating handle 6 for the gas control valve, and again the gas burner 3 is screwed to the top of the gas supply conduit. However, in this embodiment the windshield 7' is bowl shaped, and has an aperture in the centre of the bowl dimensioned to receive the gas supply conduit 5' as a tight friction fit. The exterior of the gas supply conduit 5' may be slightly tapered to enhance this effect.

Consequently, in assembling the stove I' the gas supply conduit 5 may be connected to the gas canister 12, and then the windshield 7' may be slid onto the gas supply conduit before the gas burner 3 is screwed into position at the top of the gas supply conduit.

In this embodiment the sidewall 9' of the windshield 7' is not castellated, but instead is dimensioned to be received as a secure friction fit within the lowermost peripheral part of the dome shaped bottom wall 23 of the receptacle 2. In this way a positive connection is created between the support formed by the windshield 7' and the receptacle 2 to prevent the receptacle from sliding should the cooker 1' tilt.

The windshield 7' again forms, when mounted on the gas supply conduit, an annular trough 11' that surrounds the gas supply conduit. However, the windshield 7' is provided with a plurality of radial ribs 30 that mimic the radial ribs 24 in the bottom wall 23 of the receptacle 2. In fact the windshield 7' has a complementary bowl shape to the shape of the bottom wall 23. In this embodiment the apertures 31' are circular.

The lid 26' is similar to that of the first embodiment, but the recess 28' is dimensioned to receive only the gas burner 3, rather than the gas supply conduit.

Figure 5 shows the stove of the second embodiment ready for use, and Figure 6 shows the stove when dismantled and packed away. The components of the stove have been separated and the gas burner 3 has been accommodated in the recess 28' in the lid 26'. The windshield 7' has been inverted and introduced into the cavity defmed beneath the dome shaped bottom wall 23 of the receptacle 2. The complementary shape of the windshield 7' ensures that it fits neatly against the bottom wall 23 of the receptacle 2 using the snap fingers 19.

The connector of the gas supply conduit 5 that was screwed to the stub of the gas canister 12 has now been screwed to the stud 21 provided on the base 17, and the base 17 has been snapped into position on the bottom of the receptacle 2. Thus the windshield 7' and the gas supply conduit are both stored in the space between the base and the bottom wall of the receptacle.

Figure 7 shows some of the components of the embodiment of Figures 5 and 6 in an alternate configuration. The connector of the gas supply conduit is screwed to the stud 21 of the base. The windshield 7' is positioned on the gas supply conduit, but the gas burner 3 can be omitted and stored in the lid if desired. The receptacle 2 is mounted on the support constituted by the windshield 7'. A solid fuel or a liquid fuel may be introduced to the annular trough 11'. The fuel may be ignited to heat the contents of the receptacle. The components of the stove may be used in this way if all of the gas cartridges have been exhausted.

Looking now again at the embodiment of Figures 1 to 4 it can be seen that this embodiment also can be used without the gas cartridge, with the gas supply conduit being connected directly to the base, and with solid or liquid fuel being placed in the trough 11.

In the described embodiments the sidewall 25 of the receptacle 2 is made of stainless steel. However, the waIl 25 may have many other forms to provide the desired heat insulating properties. The sidewall may be made of any appropriate material which has low thermal conductivity, or may be made of a twin wall construction, possible with the space between the twin walls being evacuated, or being ifiled with a thermal insulator. Exterior thermal insulating material may also be applied to the wall.

The gas cartridge 12 that has been described is of a type known in the art. Other types of gas cartridge are also known, and may be used in embodiments of the invention, with the relevant parts of the stove being designed appropriately. For example, some cartridges are designed to be held in a cage or housing, with the cage or housing defming a threaded bore, located immediately above the centre of the top wall of the gas cartridge, to receive a threaded part of the gas supply conduit. The lowermost part of the gas supply conduit includes a sealing element to engage the surface of the gas cartridge in a gas tight manner, and an internal blade to pierce the carthdge to enable gas to flow through the bore of the gas supply conduit. It is envisaged that the stoves described above could easily be adapted for use with such a cartridge.

The base 17 has been described as having ground-engaging teeth 22. The base may alternatively be provided with other ground engaging components to enhance the stability of the stove, including, for example, pivotally mounted feet that can be swung out from a retracted position to an extended position to increase the effective diameter of the base.

It is envisaged that in a modified embodiment of the invention, the receptacle maybe made to have an internal diameter slightly greater than the external diameter of the gas cartridge. If the embodiment of Figures 5 to 7 were to be modified in this way the gas cartridge could be stored within the receptacle when the stove was dismantled. It would, of course, be necessary to provide the base with two sets of resilient snap fmgers 19, with one set being configured to engage the bottom of the receptacle, and another set configured to engage the bottom of the gas cartridge. This would provide a further saving of space when the stove is dismantled and packed away, with the gas cartridge contained within the receptacle.

In the described embodiments the positive engagement between the windshield and the receptacle is achieved by the interconnection between a castellated upper part of the sidewall of the windshield and a ribbed bottom wall of the receptacle, or a simple friction fit. In alternative embodiments the positive engagement could be achieved with a screw thread-type connection, or event a bayonet connection.

It is believed that a stove and receptacle combination as described above may find favour with those who wish to break camp' rapidly. The stove may be packed away, in many cases while a hot drink is still retained within the receptacle.

The stove has been described as incorporating a gas cartridge. However, as gas cartridges are frequently of an industry standard' design, it would be quite practicable for the stove to be sold without a gas cartridge, as the purchaser would readily be able to obtain a gas cartridge to fit the stove.

It is envisaged that a thermometer could be incorporated into the receptacle, or the lid of the receptacle, to enable the temperature of the contents of the receptacle to be determined without removing the lid of the receptacle.

Claims

Claims 1 A portable stove and receptacle combination, wherein the stove comprises a gas burner, a supply conduit to supply gas to the burner, the supply conduit having a connector to connect the supply conduit to a gas canister, and a support arrangement to support the receptacle above the burner; the receptacle having a bottom wall and a side wall, the bottom wall having relatively high thermal conductivity, and the sidewall having relatively low thermal conductivity; the combination further comprising a base of thermally insulating material, the base being configured to be connected to the bottom of the stove to provide stability for the stove, and also to be connected to the bottom of the receptacle to provide thermal insulation for the bottom wall of the receptacle.
2. A stove combination according to claim 1 wherein the support arrangement is a windshield, the windshield being directly connectable to the receptacle with a positive connection, the bottom wall of the receptacle and the windshield together forming a chamber surrounding the gas burner, there being inlet/outlet apertures to enable air to reach the burner, and to permit exhaust gas to escape from the chamber.
3. A stove combination according to claim 2 wherein the windshield is configured to contain liquid fuel or solid fuel.
4. A stove combination according to claim 2 or 3 wherein the bottom wall of the receptacle is dome shaped, and the windshield has a complementary bowl shape, so that the windshield, when inverted, can be accommodated within the dome shaped bottom wall of the receptacle.
5. A stove combination according to any one of the preceding claims further incorporating a gas cartridge, the bottom of the gas cartridge constituting the bottom of the stove.
6. A stove combination according to claim 5 wherein the bottom wall of the gas cartridge is dome shaped, and the windshield has a complementary bowl shape, so that the windshield, when inverted, can be accommodated within the dome shaped bottom wall of the gas cartridge.
7. A stove combination according to claim 3 or any claim dependant thereon wherein the base is provided with a complementary connection to engage securely with the connector of the supply conduit.
8. A stove combination according to any one of the preceding claims wherein the receptacle has a lid of thermally insulating material, the lid having a recess to accommodate at least one component of the stove.
9. A stove combination according to claim 5 or any claim dependant thereon wherein the gas cartridge is dimensioned to be received within the receptacle.
10. A stove combination according to any one of the preceding claims wherein the bottom wall of the receptacle is provided with ribs or fms.
11. A stove combination according to any one of the preceding claims wherein the base is provided with a plurality of ground-engaging teeth.
12. A stove combination according to any one of the preceding claims wherein the receptacle, or the lid of the receptacle, incorporates a thermometer to enable the temperature of the contents of the receptacle to be determined without removing the lid of the receptacle.
13. A stove and receptacle combination substantially as herein described with reference to and as shown in Figures 1 to 4 of the accompanying drawings.
14. A stove and receptacle combination substantially as herein described with reference to and as shown in Figures 5 to 7 of the accompanying drawings.