Portable camping stove

Abstract

A camping stove incorporating a pair of tubular chambers each chamber having an aperture in the side. Each tube has a concentric tightly fitting secondary tubular chamber inside, which secondary tube contains fuel impregnated fibrous packing material. The secondary tubes also have apertures in the side which can be moved into alignment with the burner apertures in the outside tubes so as to permit ignition of the fuel therein. The tubes are mounted in a box with a grill type structure. The box has a foldable top with folding wind shields thereon and legs that fold around to lock the top closed so as to permit the entire stove to close up into a compact easily portable box.

Description

BACKGROUND OF THE INVENTION

Small portable camping stoves which burn a liquid fuel such as gasoline or alcohol are well known in the prior art. Generally, these stoves comprise a fuel tank which must be pressurized by hand. The pressurized fuel is then forced out through an adjustable valve and burner arrangement. These prior art stoves are expensive and complicated. They must be periodically pumped to maintain a sufficient pressure in the fuel tank. Because they use a pressurized system, a number of pressure fittings are required along with a fairly sophisticated pumping apparatus. Since the pressure varies, the size of the flame varies and therefore the valve controlling the fuel flow must continually be adjusted. In a camping environment, it is difficult enough to prepare a meal without the added burden of continually adjusting and pumping the stove to keep it operating properly. Other problems include leaks that develop in the pressurized fuel tanks during storage especially if there is some residual pressure from the previous operation. It would be more desirable if a compact stove could be provided which would require no pumping, burn a steady, even flame without adjustment and yet still permit easy refueling and provide an easily adjustable flame. My invention accomplishes these ends as described hereinafter.

SUMMARY OF THE INVENTION

Briefly, my invention proposes a new type of camping stove having a compact folding housing and a unique burner assembly. The burner assembly comprises two concentric tubes which are slidable, one within the other but yet are sized so that they fit snugly together providing a good seal therebetween. The inside tube is filled with a nonflammable, fibrous packing material such as asbestos, which material can be saturated with a suitable fuel such as alcohol. One of the tubes is rotated or slid axially with respect to the other tube by means of a handle fastened to it so as to bring an aperture in the inside tube into alignment with an aperture in the outside tube. The amount of overlap between the two apertures determines how much of the fuel soaked packing material is exposed to the outside air and therefore the size of the flame. The fuel burns steadily without the need of any adjustments or attention, flowing automatically from the fibrous packing material. Since the flame size is determined by the area of the opening, a steady, controllable flame may be produced of any desired size merely by changing the opening size through sliding or rotating the tube.

Refueling is easy. The holes are simply moved into alignment and fuel is poured in until it saturates the packing material. No pressurization is involved and no pump is necessary. No pressure fitting or special valves are necessary to control the fuel flow. In the alternative, the inside tube may be completely withdrawn from the outside tube and refueled from one end.

The flame is easily extinguished simply by closing the aperture, again by sliding or rotating the tube. It has been found that the tubes remain cool and can even be touched immediately after the flame ceases. This is advantageous in that the fire and burn hazard from hot metal is reduced. The cool condition is believed to be a consequence of the continual evaporation of fuel in the inside tube as it is drawn off for burning.

Any number of these paired concentric tube burners may be mounted in a housing to provide a stove. In the preferred embodiment, two sets of concentric tubes are shown mounted in a housing of special design. The special housing comprises a metal box having foldable legs, top, and wind shielding sides to insure a well protected environment for the burners. The legs, top and sides all pivot together to provide a compact carrying case for the stove.

The shape and arrangement of the apertures in the inside and outside tubes may be varied widely to provide different burner arrangements with different operational characteristics. These will be discussed in greater detail below.

It may therefore be seen that it is an object of my invention to provide an improved camping stove. It is a further object to provide a compact folding stove having maintenance free burners which are easy to adjust and refuel. Further objects and advantages will become apparent upon consideration of the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the camp stove of my invention showing the stove in an open, operational condition;

FIG. 2 shows my camp stove folded down for easy transport;

FIG. 3 is a partially cutaway side view of one of the burners in the preferred embodiment of my stove;

FIGS. 4 and 5 show two possible variations of the preferred embodiment of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1 and 2, a portable camp stove is shown, in open and folded conditions, comprising a generally rectangular metal box 10 with a cover 12 hinged thereon. Cover 12 pivots about two small tabs 13 which rest in small holes in the corner of box 10. A pair of wind protectors or shields 11 are pivoted on cover 12. Wind shields 11 have small tabs 14 which extend through holes in four tabs 15. Tabs 15 are cut out of top 12 and bent into the position shown in FIG. 1. The left wind shield in FIG. 1 is cut away to better show the contents of box 10 but both shields 11 rest on small pins 17 mounted in slots 19 in box 10. It is apparent in FIG. 1 that the whole box can be easily folded together into the compact portable configuration of FIG. 2. Pins 17 are rotated 90.degree. to drop into box 10, the wind shields 11 are rotated to lie flat against the inside surface of top 12, and top 12 is then closed and held in place by rotating a pair of legs 23 in their holes 25 from the position of FIG. 1 to the position of FIG. 2. Legs 23 are held in the position of FIG. 2 by small risers or bumps 29 formed in the front of box 10. A handle 27 may be formed from wire and mounted through two suitable holes in the front of box 10.

Returning to FIG. 1, mounted over the top of box 10 is a grill 16 upon which various utensils may be rested above the burners. The burner assembly comprises a pair of tubes 18 mounted in box 10. Tubes 18 are described in greater detail with respect to the cutaway side view of FIG. 3.

In FIG. 3, it may be seen that each outside tube 18 is mounted between the walls of box 10. Inside of each tube 18 is a concentric, snugly fitting tube 20. A generally rectangular hole 22 in tube 18 faces upwards in box 10 to comprise the burner opening. Tube 20 also has a rectangular hole 24. As described earlier, the inside tube 20 is filled with a fibrous packing material 26 which may comprise asbestos fiber or any other suitable nonflammable material. The packing material 26 is saturated with a suitable fuel such as alcohol. During storage, tube 20 is rotated to a position at which holes 22 and 24 do not overlap at all. Tube 20 is fitted snugly in tube 18 so that a seal is produced and no leakage results. Since the liquid fuel is held in place by the packing material, it is only necessary to prevent leakage of vapor. Thus, the snug fit provides a sufficient restriction on normal convective air flow to insure that no leakage results.

Tube 20 is closed at the righthand end and welded to a shaft 28 which, in turn, is connected to a handle 30. With the use of handle 30, tube 20 can be rotated so as to overlap apertures 22 and 24. This action exposes the alcohol saturated packing material which can then be ignited. The fuel burns over the area of aperture 24 which is exposed by aperture 22. Additional rotation of handle 30 exposes greater amounts of aperture 24 allowing a larger flame. To extinguish the flame, handle 30 is simply rotated so as to roll aperture 24 out of alignment with aperture 22 thus cutting off the oxygen supply, effectively snuffing the flame, and once again sealing in the fuel material. As mentioned, the tubes 18 and 20 remain cool to the touch during burning thus reducing the hazard of burns and fires.

In FIG. 4, it may be seen that another method of operating the stove involves sliding tube 20 axially along tube 18 so as to move aperture 24 to a position beyond aperture 22. Progressively larger flames can be produced by pushing tube 20 inward thus overlapping more and more the ends of apertures 22 and 24. If desired, tube 20 can be completely removed from tube 18. Since tube 20 is open at the left end, it can be readily refueled or repacked, if necessary, from the exposed end. This easy disassembly also permits the stove and burner apparatus to be quickly and easily cleaned. This is an especially desirable feature when food spills on the burners during cooking and the like.

It is readily apparent that many different configurations of apertures may be utilized to produce different types of burners. For example, in FIG. 5 an outside tube 32 is shown having three holes 34 therein. The inside tube is accordingly provided with three holes 36 which can be rotated into alignment with holes 34 by means of a handle 38.

Yet another embodiment may involve a long, narrow slot rather than discrete holes. The holes, of course, need not be rectangular but could be oval or round or even triangular shaped so that a small corner is opened initially for a very small flame and then, as the rotation of the tubes relative to each other is increased, the hole size is increased quickly to provide a large flame.

Another possible arrangement could utilize a spiral groove in one or more of the tubes so as to provide a changing axial location of the overlapping portion of the slots so that the flame may be positioned anywhere along the length of tube 18. Still another arrangement could use non-cylindrical tubes having rectangular cross-sections, for example. It is also possible to produce burners wherein the inside tube would be fixed to the housing and the outside tube caused to slide along or rotate about the inside tube. Numerous other arrangements will be obvious to those having ordinary skill in the art and therefore I intend to be limited only by the appended claims.

Claims

I claim:

1. A portable stove comprising:

a housing having side walls;

a plurality of burner assemblies mounted to said housing between two side walls, each of said burner assemblies comprising a first cylindrical chamber having first aperture means in one side, a second cylindrical chamber rotationally and axially movably mounted inside said first chamber and in intimate sealing contact therewith, said second chamber having second aperture means in one side;

a handle extending outside a side wall connected to an end of said second chamber so as to allow said second chamber to be moved to various positions having varying degrees of overlap between said aperture means; and

a fuel absorbent packing material in said second chamber adapted to be saturated with inflammable fuel, which fuel can be burned when exposed to the air by a suitable alignment of said aperture means.

2. The apparatus of claim 1 in which said aperture means comprise generally rectangular openings in the walls of said cylindrical tubes.

3. The apparatus of claim 1 in which said aperture means comprise a plurality of openings in the walls of each tube.

4. The apparatus of claim 3 further including a grill mounted on said housing over said burner assemblies.

5. The apparatus of claim 4 further including: a folding top, folding side wind shields and folding legs attached to said housing.

6. The apparatus of claim 5 in which said wind shields fold against said top and said top folds down to close said housing and said legs fold around said housing to hold said top closed.