Adjustable burning canned heating apparatus

A disposable, adjustable flame, canned fuel apparatus comprises a container having closed sides and bottom and having an open top; a fuel absorbent pad disposed in upper regions of the container relatively adjacent to its open top; a flammable liquid disposed in the container; an elongate wick disposed in the container and having an upper end region in fluid communication with the pad and having a lower end region extending into lower regions of the container and into the flammable liquid contained therein; and an adjustable flame assembly attached across the top of the container. Such assembly includes a first member non-rotatably attached to the container and a second member that is mounted for rotational movement relative to the first member or the first member mounted for rotational movement relative to the second member and a second member that is non-rotatably attached to the container or both first and second members mounted to the container for rotational movement relative to each other, the first member having a plurality of apertures opening to an upper surface of the fuel absorbent pad and the second member having a like number of similar apertures and being rotatable between a first rotational position relative to the first member in which the apertures in the first member are covered by the second member and a second rotational position in which the apertures in the first member are at least substantially uncovered for maximum burning of fuel in the container. In rotational positions intermediate the first and second positions, the apertures in the first member are partially closed. The pad is formed of a mixture of fiberglass and cotton, the cotton being present in an amount of between about fifteen percent and about eighty-five percent. A seal is provided for retaining the flammable fluid in the container until use.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates generally to the field of heating and cooking 
apparatus and more particularly to disposable, canned fuel heating and 
cooking devices. 
2. Background Discussion 
The use of disposable, self-contained canisters or containers of heating 
and cooking fuel is widely known for camping and in emergency situations 
where utility sources of gas and electricity are out of service, for 
example, in the event of earthquakes, hurricanes and other disasters. One 
common type of such cans of heating and cooking fuel is STERNO, which is 
sometimes referred to as "canned heat." STERNO cans are similar in 
appearance and construction to half-pint paint cans and have the same type 
of removable and replaceable covers as paint cans. The fuel contained in 
the cans is a gel-type fuel. In use, the cover is removed and the fuel is 
ignited to provide a flame. A cooking utensil is placed on top of the can 
for cooking purposes. Such cans of heating and cooking fluid are 
relatively inexpensive, are readily stored for protracted periods of time 
and are disposable when the contained fuel is completely consumed. 
Other types of canned fuel heating and cooking devices are also known. For 
example, U.S. Pat. No. 4,624,633 to David Bandel discloses a high 
percentage glycol fuel and a fuel canister used to contain the fuel. A 
wick protruding from the top of the canister provides a flame for heating 
and cooking. U.S. Pat. No. 4,611,986 to J. Alan Mentor discloses a 
particular configuration for use with a canister of fuel, the wick, which 
extends upwardly from the top of the canister is split, flame control 
being provided by separation of the two wick sections. 
As another example, U.S. Pat. No. 4,604,053 to Rudolpho de la Rosa 
discloses another fuel-containing canister device in which an elongated 
wick having two separate end regions that extend into the fuel contained 
in the canister. A central region of the wick is exposed for burning 
through an aperture in the top of the canister. Further, U.S. Pat. No. 
3,888,620 to Harry J. Devon discloses a heat and cooking source that 
employs a solid wax contained in the burner canister. When exposed regions 
of a wick are lit, metal wires conduct heat into the body of wax in the 
canister, thereby melting it so that the fuel becomes a liquid which is 
readily burned to provide more heat than is provided, for example, by a 
wax candle. 
U.S. Pat. No. 4,850,858 to Robert J. Blankenship et al discloses another 
type of canned heat device in which a disc-shaped plastic foam burner pad 
is disposed at the top of a liquid fuel canister, a wick extending between 
the pad and fuel in the container wicks fuel into the foam pad. A central 
region of the plastic foam pad is exposed through an opening in the top of 
the canister and is lit to provide a heating and cooking flame. 
U.S. Pat. Nos. 960,064 to Samuel Bergstein and No. 3,262,290 to Georg Huber 
disclose other types of liquid fuel burners. 
One disadvantage of such known heating and cooking devices is that the 
control of the amount of flame and heating area is difficult to vary 
according to particular user needs. For example, the more simple devices 
provide no burning control whatsoever. Once lit and burning, the fuel 
provides a generally uniform heat output until the fuel is entirely 
consumed. Depending upon the use, such lack of control of heat output is 
undesirable and the result may be burned food, excessive heat (for 
example, in a small tent) and very rapid consumption of fuel. In other 
devices, the extent of burning control is not adequate for many uses where 
heat control, such as is commonly provided by a conventional gas or 
electric stove, is needed. 
For these and other reasons, the present inventor has invented an improved, 
flame adjustable fuel container apparatus in which the amount of burning 
and heat provided by combustion of the contained fuel is adjustable over a 
wide range between an "off" condition, to a full "open" condition. 
SUMMARY OF THE INVENTION 
In accordance with the present invention there is provided a flame 
adjustable canned fuel apparatus which comprises a container for holding a 
quantity of flammable liquid, the container having closed sides and bottom 
and having an open top; a fuel absorbent pad disposed in upper regions of 
the container relatively adjacent to the open top; and an elongated wick 
disposed in the container, the wick having an upper end region in fluid 
communication with the pad and having a lower end region extending into 
lower regions of the container. 
Included in the apparatus is an adjustable flame assembly that is attached 
across the top of the container. Such assembly includes a first member 
non-rotatably attached to the container and a second member that is 
mounted for rotational movement relative to the first member. The first 
member has at least one aperture opening to an upper surface of the pad 
and the second member is configured so that in a first rotational position 
relative to the first member, at least one aperture in the first member is 
covered by the second member and in a second rotational position relative 
to the first member, at least one aperture in the first member is at least 
substantially uncovered. 
The second member is constructed so that in rotational positions 
intermediate its first and second positions, at least one aperture in the 
first member is partially closed. Accordingly, rotational movement of the 
second member relative to the first member enables the manual adjustment 
of the amount of the pad that is exposed through at least one aperture in 
the first member, thereby enabling the amount of heat provided by the pad, 
when it is lit, to be varied according to the amount of heat required, the 
length of the burning time of the apparatus being thereby also controlled. 
Preferably, both the first and second members are provided with a number of 
apertures so that a uniform burning and heat release over the top of the 
apparatus is enabled. 
A flammable liquid, such as alcohol, is contained in the container. A seal 
is preferably provided for retaining the flammable fluid in the container 
and keeping it from evaporating during storage. In an embodiment, the seal 
comprises a removable metal foil disposed between the first and second 
members of the adjustable flame assembly, the seal being adhered to the 
first member and upper edges of the container. 
In accordance with a preferred embodiment of the invention, the pad is 
formed of a mixture of fiberglass which is non-combustible and cotton 
which is combustible, the percentage of cotton preferably varying from 
about fifteen percent to about eighty-five percent. By increasing the 
cotton content (that is, its percentage in the composition), the rate of 
burning of the apparatus is increased over the rate of burning in the 
apparatus when a lower percentage of cotton is present. Different burn 
rate and heat providing types of apparatus can thereby be provided and can 
be selected by buyers according to their particular requirements. 
The adjustable flame assembly is not limited to a first member 
non-rotatably attached to the container and a second member that is 
mounted for rotational movement relative to the first member. Instead, the 
first member can be constructed for rotational movement and the second 
member can be non-rotatable or both first and second members can be 
constructed for rotational movement.

DETAILED DESCRIPTION OF THE INVENTION 
There is shown in FIGS. 1 and 2 a disposable, flame adjusting, liquid fuel 
apparatus 10 in accordance with the present invention. Generally 
comprising apparatus 10, as more particularly described below, are a 
container or canister 12, a burner pad 14 disposed in upper regions of the 
container, a wick 16 disposed in the container, liquid fuel 18 contained 
in the container, and a flame adjusting assembly 20. 
Container 12 is formed having a closed bottom 24 and closed sides or side 
wall 26, being open at the top (FIG. 2). As shown, container 12 is 
generally cylindrical in shape. With no limitation intended or implied, 
container 12 may conveniently have a diameter, D, of about three inches 
and a side height, H, of about two inches, and may be constructed of 
aluminum or tin. 
Burner pad 14 is preferably the same diameter as container 12 and may have 
a thickness, t, of about one-quarter to three-eights of an inch. Pad 14 is 
preferably constructed of a mixture of fiberglass, which is essentially 
non-burning, and cotton which is consumed in the burning process. The 
amount of cotton contained in pad 14 may, for example, vary from about 
fifteen percent to about eighty-five percent. To a large extent, the 
percentage of cotton comprising pad 14 determines the burning rate of fuel 
18 in apparatus 10, all other facts being the same. That is, the greater 
the percentage of cotton, the faster fuel 18 burns and the greater is the 
heat output rate (for example, in BTU's per given period of time). 
As shown in FIGS. 1 and 2, pad 14 may be retained in place by a retainer 
disc 28 which may be formed of a metal screen or mesh and upon which a 
lower surface 30 of the pad rests. Retainer disc 28 may, in turn, be held 
in place b the edges thereof being received in an annular groove or bead 
32 formed outwardly around side wall 26 of container 12. 
Wick 16 comprises an elongate section or strip of conventional wick 
material, such as woven cotton. A lower end region 36 of wick 16 extends 
to the bottom of container 12 so as to remain in contact with fuel 18 as 
long as any fuel remains in container 12 (FIG. 2). An upper end region 38 
of wick 16 extends through retainer 28 and into fuel transfer contact with 
under surface 40 of pad 14 (FIG. 2). Liquid fuel 18 is thereby caused to 
be soaked into pad 14 to enable the burning of fuel from the pad. 
Flame adjusting assembly 20, which is attached across the open top of 
container 12, is configured for causing a selective area exposure of an 
upper surface 40 of pad 14 to the air for burning of fuel 18 that has been 
wicked into the pad by wick 16. As shown by way of example in FIGS. 1 and 
2, assembly 20 comprises first and second circular members 42 and 44, 
respectively. Members 42 and 44 are formed having at least one aperture 46 
and 48, respectively. Preferably, as shown in FIG. 1, a large, like number 
of similar apertures 46 and 48 are formed in members 42 and 44. For 
reasons that will become apparent, the pattern of apertures 48 in second 
member 44 is identical to the pattern of apertures 46 in first member 42. 
First member is non-rotatably attached to the top of container 12. Such 
attachment may be accomplished by forming an annular bead 50 outwardly 
around container side 26 adjacent an upper edge 52 of such side, as best 
seen in FIG. 5. First member 42 is constructed having a narrow flange 54 
that extends downwardly for a transverse, circular top portion 56. 
Extending around flange 54 is an annular bead 58 which is configured for 
snapping into bead 50 on container side 26 when the first member is forced 
downwardly into container 12. An interference fit between bead 58 of first 
member 42 and bead 50 of container prevents rotational movement of the 
first member relative to the container. The snapping of first member 42 
into container 12 in the above-described manner may be facilitated by 
forming first member flange 54 with one or more narrow vertical slits 60 
(FIG. 5). 
Second member 44 is constructed to be rotatably attached to container 12. 
To this end, second member 44 is constructed having a narrow flange 64 
which projects downwardly from a top, transverse portion 66 (FIGS. 1 and 
5). An annular bead 68 is formed around second member flange 64 and is 
sized to fit closely but not tightly over bead 50 formed around container 
side 26 when second member 44 is snapped into place onto container 12. 
One or more slits 70 may be formed vertically in second member flange 64 to 
enable snapping of second member 44 into place onto container 12. Second 
member 44 fits sufficiently loosely onto container 12 so that the second 
member can be rotated around the container, for example, by the use of a 
tab 72 which projects sidewardly from the second member. On the other 
hand, second member 44 fits snugly enough onto container 12 that the 
second member is frictionally retained in whatever rotational position it 
is moved into. 
Because the size and pattern of apertures 48 in second member 44 (FIGS. 4a, 
4b and 4c) match the size and pattern of apertures 46 in first member 42, 
it can be appreciated that in a certain, first rotational position of the 
second member relative to the first member, apertures 46 in the first 
member are closed by regions between apertures 48 in the second member. 
Depending upon the number and pattern of apertures 46 and 48, more than 
one of such first rotational positions may be provided. 
Second member 44 can them be rotated to a second rotational position 
relative to first member 42 such that apertures 48 in the second member 
are aligned over apertures 46 in first member 42 (FIG. 4b). In this second 
position, exposed regions 80 of pad 14 can be lit and will burn. Again, 
according to the number and pattern of apertures 46 and 48, more than one 
of such second rotational positions may be provided. 
It will be apparent that for rotational positions of second member 44 
relative to first member 42 intermediate the above-described first 
(closed) and second (open) positions, apertures 46 in the first member 42 
may be partially exposed through apertures 48 in the second member (FIG. 
4c), thereby providing a selectively variable burning area of pad 14. The 
amount of heat provided by apparatus 10 can accordingly be adjusted 
between none (second member 44 in its first, closed position) and full 
burning (the second member in its second, open position). 
The size and shape of the apertures in first and second members 42 and 44 
may, of course, be different from relatively small and circular. For 
example, there is depicted in FIG. 3 a first member 42a having triangular 
or circular segment-shaped apertures 46a. In such case, similar sized, 
shaped and spaced apertures would be formed in the second member (not 
shown). 
It is generally desirable in the use of liquid fuel 18 in container 12 to 
seal apparatus 10 against leakage and evaporation of the fuel. This is 
desirable not only to enabling the storing and transportation by apparatus 
10 in a safe manner, but also to prevent the possible formation of an 
explosive fuel-air mixture in storage areas. 
One manner of sealing container 12 closed is to install a metal foil seal 
84 across the top of the container over first member 42, as depicted in 
FIG. 1. Seal 84 is preferably sealed around upper edge 52 of container 12 
after first member is attached to the container in the manner described 
above. Second member 44 can then be snapped onto container 12 over both 
seal 84 and first member 42. When use is to be made of apparatus 10, 
second member 44 is unsnapped from container 12, seal 84 is pealed away 
and the second member is then snapped back onto the container. Seal 84 may 
be made so that it can reseal container 12 if desired. In which case, the 
reverse process of unsealing would be followed. 
Although there has been described and illustrated a disposable, adjustable 
flame, canned fuel apparatus for purposes of illustrating the manner in 
which the invention may be used to advantage, it is to be appreciated that 
the invention is not limited thereto. Therefore, any and all variations 
and modifications that may occur to those skilled in the applicable art 
are to be considered as being within the scope and spirit of the claims as 
appended hereto.