Cooker

Abstract

 A cooker has a combustion chamber surrounded by a sleeve. The combustion chamber has an inlet means consisting of a pipe passing through the sleeve and into the combustion chamber. The combustion chamber rests on a flue box which has an inlet aperture connected to the space between the sleeve and the combustion chamber, and an outlet aperture connectable to a chimney or stack. The flue box comprises a base tray with peripheral flanges and an upper surface on which surface the inlet and outlet apertures are formed. The upper member has downwardly directed side walls that releasably engage the flanges of the tray forming a substantially smoke tight flue box.

Description

[0001] This invention relates to stoves.

[0002] According to one aspect of the invention there is provided a stove comprising a combustion chamber surrounded by a sleeve and having air inlet means thereto passing through the sleeve, and a flue box having an outlet aperture connectable to a chimney or stack and an inlet aperture connected to the space between the combustion chamber and the sleeve characterised in that the flue box comprises a tray having peripheral flanges and an upper member having an upper surface in which the said apertures are formed and downwardly directed side walls that releasably engage the said flanges to form a substantially smoke tight flue box.

[0003] Preferably, the peripheral flanges of the tray are upwardly directed and the upper member is slidably received within the area defined by the peripheral flanges.

[0004] Preferably the flue box at the inlet aperture is provided with locating means to locate the sleeve in position above the aperture and preferably the locating means is a U-section recess surrounding the inlet aperture.

[0005] The stove may further comprise a chamber which is located above the flue box and which is adapted to receive therein food to be cooked or heated, the chamber having flue means thereabout connected to the flue box so that heated gases can pass around the chamber to heat the interior thereof. Preferably the chamber has a closable door.

[0006] An embodiment of the invention will now be described by way of example with reference to the accompanying drawings.

[0007] In the drawings:

Figure 1 is a perspective view of the stove of the invention,

Figure 2 is a cross-section on line 2-2 of Figure 1,

Figure 3 is a side view of Figure 1, and

Figure 4 is a side view of the stove with a water heater attached thereto.

[0008] Referring now to the drawings there is shown a stove 10. The stove 10 comprises a low, elongated, rectangular, parallipipedical flue chamber or box 11 comprising a tray 12 and an upper member 14 both made of sheet metal.

[0009] The tray 12 consists of a base 16 and peripheral upwardly directed flanges 18, the sides of which butt against each other. Two pairs of legs 20 are spot welded to the lower surface of the tray 12 to carry the flue box.

[0010] The upper member .14 consists of a flat upper surface 22 and dependant side walls 24, the sides of which butt against each other. The free ends of the side walls 24 have inwardly directed rims 26.

[0011] The side walls 24 of the upper member 14 fits snugly within the flange 18 of the tray 12 with the rims 26 resting on the base 16 of the tray 12 to hold the upper member 14 and tray 12 firmly but releasably together.

[0012] There are three apertures 30, 32 and 34 in the upper surface 22 of the upper member 14, the largest being located at one end of the flue box 11 and the smallest near the other end. The largest aperture 30 and middle aperture 32 are surrounded by U-section annular recesses 36 and 68 respectively pressed into the surface 22. The smallest aperture 34 has fixed therein a flanged chimney 38 which tapers at its free end. A flue pipe 66 fits over the chimney 38.

[0013] An open ended cylindrical fire box 40 fits over the aperture 30. The fire box 40 comprises a cylindrical outer sleeve 42 and a coaxial inner cylindrical combustion chamber 44. The lower end of the sleeve 42 fits into the recess 36 preventing lateral movement thereof. The combustion chamber 44 comprises a cylindrical side wall 46 and a base 48. The top of the side wall 46 of the combustion chamber 44 is a few centimetres lower than the top end of the sleeve 40.

[0014] Within the combustion chamber 44 is a grate 52 which . is removable and which is situated approximately at the midpoint of the axial length of the combustion chamber 44. The grate comprises plate metal perforated with 8 mm and 10 mm diameter holes 50.

[0015] Four equispaced externally threaded, internally deburred and polished radial air inlet pipes 54 pass through the sleeve 42 and side wall 46 spanning the annular space therebetween to supply air below the grate 52. Nuts 56 are threaded on to the inner and outer ends of the pipes 54 within the side walls 46 and the outside of the sleeve 40 respectively. The grate 52 is' supported at its periphery on the nuts 56.

[0016] The pipes 54 also support the combustion chamber 44 within the fire box 40.

[0017] The flat disc 60 covers the aperture 32 in the centre of the surface 22 of the body 14 (see Figure 2).

[0018] The chimney 38 contains a butterfly valve 62 to vary the draft therethrough. An external handle 64 controls the position of the butterfly valve 62. Flue pipes 66 extend from the chimney 38 to the desired height normally to the exterior of the habitation in which the stove is used. The stove is used as follows:

Solid fuel is placed on the grate. This fuel may comprise any combustable material such as wood, chips, coal, charcoal and maize husks. The sleeve 42 is covered with a cooking pot (not shown) to inhibit the escape of gases from the fire box. The disc 60 is now lifted and a small fire is ignited within the flue box 11 e.g. by burning a sheet of paper and the disc 60 is replaced. This will warm the flue box and will cause a flow of air in the direction of the chimney 38. After this fire has burnt for a short period, the cooking pot is lifted and the fuel on the grate is ignited. The cooking pot is replaced on the sleeve. The fuel will now burn, heating the contents of the cooking pot.

[0019] If the base diameter of the pot or pan is not large enough to cover the top end of the fire box 40, a metal ring (shown in Figures 2 and 3) may be placed on the fire box 40 to carry the pot or pan.

[0020] A second cooking pot can be placed above the central aperture 32 with the disc 60 removed and will be warmed by gases passing along the flue box.

[0021] We have found that adequate heat for cooking and warming is provided by the stove and that very little smoke escapes during cooking.

[0022] We have found that the stove is very efficient particularly when of the following dimensions:

[0023] We have found that very complete combustion of the fuel takes place leaving a minimal amount of ash. The flue box 11 is very simple to clean, when necessary, by simply sliding the tray 12 away from the body and washing or wiping it down.

[0024] The stove is cheap and easy to manufacture, it is robust, portable and its use is not dependant upon obtaining any particular fuel.

[0025] The invention is not limited to the precise constructional details hereinbefore described or as illustrated in the drawings. For example, the dimensions may be changed according to the requirements. Further the air tubes 54 may be fixed.

[0026] Each air tube may be provided with one or more flanges butting against the sleeve and/or combustion chamber.

[0027] Further, a chamber having an access door and being surrounded by gas passages may be provided above the flue box 11. These gas passages are suitably connected to the flue box 11 so that heated gases pass around the chamber which now acts as an oven.

[0028] Also two fire boxes as described above may be provided on either side of the chimney connector.

[0029] The upper member 14 and the sleeve 42 are chrome plated on their inner and outer surfaces. This I have found improves the efficiency of the stove.

[0030] Referring to Figure 4 there is shown a removable water heating attachment for the stove 10. This attachment comprises a container 72 removably mounted on a stand 73 which comprises a cylindrical collar 74 that receives the container 72 and legs 75. The height of the legs 75 is such that the base of the container 72 is approximately level with the base of the fire box 40. The container 72 has a removable lid 76 thereon. Near its base the container 72 has fixed thereto a tap 78 for drawing water from the container 72.

[0031] A heater for the contents of the container 72 comprises a hollow coil 74 which surrounds the combustion chamber lying in the annular space between the combustion chamber and the sleeve 42.

[0032] The ends of the coil merge with the extension pipes 80 and 82 which lead into the lower portion of the container 72 being fixed to the container wall. The pipe 80 lies close to but above pipe 82 and is provided with an upwardly directed end part within the chamber 72.

[0033] The outer sleeve 42 has a slot 86 extending a short distance down its length to accommodate the pipes 80 and 82.

[0034] In use, the container 72 is filled with water and the lid 76 placed on the container 72. The water in the coil is heated by the fire box.

[0035] Due to the extension piece 88 being upwardly directed, due to convection, water in the coil escapes therefrom in the container 72 and the coil 84 is refilled via lower pipe 82. As the water passes through the coil 84, it is heated by heat given off by the burning fuel in the combustion chamber 44.

[0036] Eventually, when the water has reached the desired temperature, it may be drawn from the container through the tap 78.

[0037] It will be noted that cooking can take place above 32 while heating the water. However, the length of the pipes 80 and 82 is such that the container 72 may be removed from stand 74 and placed over middle aperture 32 so that additional heat is obtained from both the coil 84 and the flue chamber 11.

Claims

1. A stove comprising a combustion chamber surrounded by a sleeve and having air inlet means thereto passing through the sleeve, and a flue box having an outlet aperture connectable to a chimney or stack and an inlet aperture connected to the space between the combustion chamber and.the sleeve characterised in that the flue box comprises a tray having peripheral flanges and an upper member having an upper surface in which the said apertures are formed and downwardly directed side walls that releasably engage the said flanges to form a substantially smoke tight flue box.

2. A stove as claimed in claim 1 wherein the peripheral flanges are upwardly directed.

3. A stove as claimed in claim 2 wherein the upper member is slidably received within the area defined by the peripheral flanges.

4. A stove as claimed in any one of the preceding claims wherein the flue box at the inlet aperture is provided with locating means to locate the sleeve in position above the aperture.

5 A stove as claimed in claim 4 wherein the locating means is a U-section recess surrounding the inlet aperture.

6. A stove as claimed in any one of the preceding claims further comprising support means on which the flue box is carried.

7. A stove as claimed in claim 6 wherein the support means comprise legs.

8. A stove as claimed in any one of the preceding claims wherein the air inlet means comprises a plurality of hollow pipes that enter the combustion chamber and wherein the combustion chamber further comprises removable grate means that rests on the portions of the pipes within the combustion chamber.

9. A stove as claimed in any one of the preceding claims further comprising a chamber which is located above the flue box and which is adapted to receive therein food to be cooked or heated, the chamber having flue means thereabout connected to the flue box so that heated gases can pass around the chamber to heat the interior thereof.

10. A stove as claimed in claim 9 wherein the chamber has a closable door.

11. A stove as claimed in any one of the preceding claims comprising a plurality of combustion chambers each connected to an inlet aperture in the flue box.

12. A stove as claimed in claim 11 comprising two combustion chambers.

13. A stove as claimed in claim 12 wherein the outlet aperture is located between the said two inlet apertures.

14. A stove as claimed in any one of the preceding claims wherein at least part of the stove is chrome plated.

15. A stove as claimed in claim 14 wherein the upper member of the flue box and the sleeve are chrome plated.

16. A stove as claimed in any one of the preceding claims further comprising a water heater which includes a water container, a hollow heating coil located about the combustion chamber between the combustion chamber and the sleeve, and connecting pipes connected between the ends of the heating coil and the inside of the water container so that water may pass from the water container through the coil and back to the container.

17. A stove as claimed in claim 16 further comprising support means carrying the water container whereby the water container may be supported at the same level as the flue box.

18. A stove as claimed in claim 17 wherein the support means are removable.

19. A stove as claimed in claims 16, 17 or 18 in which the connecting pipes enter the water container one above the other and in which the upper connecting pipe has an extension within the water container which extension is upwardly directed.

Drawing