Note: Descriptions are shown in the official language in which they were submitted.
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TITLE
SELF-CONTAINED CAMP HEATER
INTRODUCTION
This invention relates to a camp heater and, more
particularly, to a camp heater which is self contained and
easily transportable with a removable stack which will allow
byproducts of combustion to escape from the heater to a
position outside the enclosed area where the heater is to be
operated.
BACKGROUND OF THE INVENTION There is a need for heat and warmth in virtually
every location where individuals work and live. It is
desirable to obtain this heat in a convenient manner,
particularly where the working and/or living location changes
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frequently, such as in respect of military operations. A
further benefit is that the heater will be assembled
relatively quickly and easily at the new location.
Heretofore, in the event tents or temporary living
accommodations are provided, the interior heating apparatus
typically consisted of a heater located within the tent or
enclosure. Fuel was provided from a fuel tank located
outside the tent and a stack was installed with some
difficulty and extended from the heater to a position
outside the enclosure for safety reasons. The assembly of
the various components into an operating heater was time
consuming and fuel was generally supplied from another
source that, if missing, would not allow operation of the
heater. When a new operating location was intended, the
disassembly of the heater and its transportation in various
segments was time consuming and inconvenient.
SUNIlKARY OF THE INVENTION
According to one aspect of the invention, there is
provided a self-contained camp heater comprising a fuel
tank, a holder, a burner located within a casing, a stack
mountable on said casing and being removable therefrom, said
stack being extendable in individual segments from said
casing and acting to conduct combustion by-products from
said heater to a desired location, each of said segments of
said stack being removable from each of said other segments
of said stack, each of said segments being positioned on and
movable with said holder during transportation of said
heater and said holder, a fuel regulator to regulate the
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flow of fuel from said fuel tank and said burner, said fuel
regulator being operable to raise or lower the level of fuel
in said burner thereby to allow increased or decreased
vaporization of said fuel in said burner, said fuel tank and
said casing being positioned on said holder.
According to a further aspect of the invention
there is provided a method to provide heat to an enclosed
location comprising the steps of manually transporting a
self-contained heater having a holder in which a fuel tank,
a burner located within a casing and a stack removable from
said casing are positioned, installing said stack on said
casing with a plurality of stack segments, one of said stack
segments being connectable to said casing and a further one
of said stack segments allowing exhaust of combustion
products to a desired location, each of said stack segments
being removable from the remaining ones of said stack
segments, initiating fuel flow from said fuel tank to said
burner and commencing combustion of said fuel within said
burner, said stack segments being positioned on and movable
with said holder when said self-contained camp heater is
transported.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
A specific embodiment of the invention will now be
described, by way of example only, with the use of drawings
in which:
Figure 1 is a side, diagrammatic partial sectional
view of the camp heater according to the invention;
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Figure 2 is a plan view of the camp heater of Figure
1;
Figure 3 is a diagrammatic partial sectional view of
the collar and stack assembly used on the camp heater of Figure
1; and
Figure 4 is a diagrammatic cross-sectional view of a
regulator commonly called a zero pressure regulator.
DESCRIPTION OF SPECIFIC EMBODIMENT
Referring now to the drawings a camp heater according
to the invention is generally illustrated at 100 in Figure 1.
It comprises a fuel tank 101 and a burner casing 121 with a
removable filler knob 102 threadedly installed to form a fuel
entry passageway into the tank 101 so that upon removal, fuel
may be added to the tank 101, the fuel used being conveniently
JP8, diesel number 1 or fuel of a similar nature. The fuel
tank filler knob 102 seals the tank 101 when it is fully
tightened as may be the case when the camp heater 100 is being
transported. However, when the camp heater 100 is under
operation, the filler knob 102 is loosened thereby to allow air
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to enter the tank 101 and keep the pressure within the tank at
or near ambient conditions thereby to allow fuel flow.
A zero pressure regulator 103 (Figure 4) is attached
by a tube 104 to the fuel tank 101. The zero pressure
regulator 103 is a diaphragm type regulator which, when there
is no pressure differential, will not allow fuel to enter the
regulator 103. When pressure is reduced on one side of the
diaphragm 105 as will be described, a needle valve 106
connected to the diaphragm 105 opens and allows fuel to enter
the regulator 103. A primer knob 154 is positioned in the zero
pressure regulator 103 thereby to allow fuel to flow to the
burner as will be described when burner operation is to be
initiated.
Zero pressure regulator 103 is mounted on a threaded
screw 110 with a knurled knob 111 connected to the upper end of
the screw 110. As the knob 111 is rotated, the zero pressure
regulator 103 will move upwardly or downwardly as indicated=and
as desired by the operator thereby to increase or decrease the
fuel being provided to the burner as will be described which,
in turn, will increase or decrease the heat being produced by
the camp heater 100.
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A second and downstream tube 112 extends from the
outlet of the zero pressure regulator 103 and joins with a
burner 113, commonly known as an S-tube burner 113. S-tube
burner 113 has a cylindrical circumferential member or downtube
114 which is mounted over the uptube 113 and is separated from
the uptube 113 by spacers 120. Spacers 120 act to conduct heat
from the combustion of the fuel within the casing 121 to the
downtube 114 and thence to the uptube 113 which heat provides
the temperature required for vaporization of the fuel within
the uptube 113. Downtube 114 has two superheaters 122, 123
mounted around the downtube 114. Superheaters 122, 123 are
circular members and surround the downtube 114 as illustrated.
The lowermost portion 124 of downtube 114 is located
approximately 1 1/2 inches from the floor or base 130 of camp
heater 100.
A series of primary air holes 131 are positioned
about the circumference of the burner casing 121 to allow for
entry of the primary air used in fuel combustion. A high fire
ring 132 is connected to the inside circumference of,the burner
casing 121 and slopes upwardly at approximately a 20 degree
angle with secondary air entry holes 133 located on the upper
side of the high fire ring 132. It has been found that the
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slope of the high fire ring 132 is important for proper fuel
combustion in the particular application to which the camp
heater 100 is directed. If the slope is too small, the
combustion in the casing outside the downtube 114 and inside
the casing 121 will sputter. If the slope of the high fire
ring 132 is too large, the length of the combustion flame will
increase which can lead to smoke and inefficient combustion.
A removable window 160 is positioned on the upper end
of the casing 121. Window 160 allows observation of the
combustion conditions within the casing 121 and also allows the
insertion of a burning paper or like product to initiate
combustion in the casing 121 when the heater 100 is ignited.
A stack 134 is mounted within the casing 121 to allow
for escape of the combustion byproducts such as nitrous oxide,
carbon monoxide, carbon dioxide and the like as is well known.
Stack 134 is mounted using an internal mounting collar 140 --
(Figure 3) which allows entry of the bottom circumference of
stack 134 without extensions protruding upwardly from the
casing 121 when the stack 134 is removed which extensions are
generally sharp and can cause injury and, in any event, which
are a nuisance during transportation and in the event the
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heater 100 is to be packaged. The connection between the
stack 134 and the collar 140 is the subject of our United
States Patent 5,527,180 granted June 18, 1996.
The stack 134 is extendible; that is, the stack
134 is formed in several pieces which are concentric and
which fit within each other. Thus, there may be five(5)
pieces of stack 134, each of the pieces being approximately
one foot in length and concentrically put together such that
when the five(5) pieces are removed and assembled to extend
upwardly, the stack may be a length of five(5) feet or so.
The stack 134 is intended to be manually removable
from collar 140 and placed between the casing 121 holding
the burner generally illustrated at 141 and the fuel tank
101. When the stack 134 is in this position, the camp
heater 100 is easily transported. Two spacer plates 142,
143 are positioned between the casing 121 of the burner 141
and the fuel tank 101 with air circulation holes 144, 145
allowing air to circulate between the spacer plates 142,
143. The spacer plates 142, 143 are intended to shield the
fuel tank 101 from the heat generated by the casing 121 and
thereby to keep the fuel tank
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101 cool for safety purposes.
A bail or handle 150 is mounted on the fuel tank 101
and rotates about axis 151 as indicated. Bail 151 allows the
camp heater 100 to be easily carried and is generally mounted
with its axis 151 at a position where the camp heater 100
remains in a substantially vertical position when carried so as
to maintain the configuration of heater 100 as when it is in
its operating position.
Two valves 152, 153 are provided to stop or allow
fuel flow through the lines 112, 104, respectively. The valves
152, 153 are manually operated and prevent or allow fuel to
flow through the lines in which they are positioned.
OPERATION
In operation, it will be assumed that the camp heater
100 is being transported. In this condition, the filler knob
or fuel cap 102 will be in the fully tightened condition such
that no fuel will be allowed to exit from the fuel tank filler
tube if the camp heater 100 is inadvertently turned upside down
during transportation or mishandled. Likewise, valves 152, 153
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will be closed thereby to prevent fuel from travelling to the
zero pressure regulator 103 and through fuel line 112 to burner
141 during transportation. Thus, there will be little or no
leakage of the fuel during transportation.
Likewise while being transported, the stack 134 will
be removed from the casing 121 and located between the fuel
tank 101 and the casing 121 as is illustrated in Figure 1. The
entire camp heater 100 will be carried by bail 150 which will
be in the upwardly extending position. Thus, the camp heater
100 will be relatively easily transported in a convenient self-
contained package.
When the operating location is reached, such as in a
tent during military operations in colder weather, the camp
heater 100 will be positioned on the floor of the tent or
ground surface. The stack 134 will be removed from its
position between the fuel tank 101 and the casing 121 and the
concentric stack pieces will be separated and assembled end to
end. The bottom of the stack 134 will be inserted into collar
140 and the top of the stack 134 will be located outside the
tent so as to provide egress for the combustion byproducts
during heater operation.
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The filler knob 102 will be removed and fuel will be
added if required. Filler knob 102 will be refitted and
loosely tightened on the fuel tank 101 so that ambient pressure
will allow fuel flow from the fuel tank 101. Valves 153, 152
will be opened to allow fuel flow to the zero pressure
regulator 103 and to the burner uptube 113.
The primer knob 154 will be pushed which will allow
fuel to flow to the burner uptube 113. It is initially
intended for the fuel flow created by the primer knob 154 to
overflow the burner uptube 113 and be deposited on the floor or
base 130 of the casing 121. This is so so that the user or
operator may initiate combustion within the casing 121 by
lighting the fuel which has overflowed from the burner 141 with
a burning paper inserted through window 160. This initiates
combustion within the casing 121.
The combustion within casing 121 will create a high
temperature on the outside of the downtube 114 of the burner
141. This heat will be transferred through the spacers 120 to
the burner uptube 113 which will allow fuel vaporization to
occur within the burner uptube 113. As the fuel vaporizes in
the uptube 113, it will travel in a gaseous state downwardly in
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the circumference between uptube 113 and downtube 114 and exit
the circumference at the bottom as is illustrated by arrows
161. The vapor will be ignited within the casing 121 and
combustion will continue with the heat generated within the
casing 121 being used for heating the tent and with the
byproducts exiting from the tent through the stack 134.
The level of the fuel within the uptube 113 is
regulated by the zero pressure regulator 103. By raising or
lowering the level of the fuel in the uptube 113, the
combustion can be increased or decreased. However,
vaporization of the fuel will only occur within the uptube 113
to avoid liquid overflow from the uptube 113. If the fuel
level is higher, increased heat will result and if the fuel
level is lower, reduced heat will result. Thus, the operator
need only rotate knurled knob 111 to raise or lower the zero
pressure regulator 103 thereby to raise or lower the fuel level
within the uptube 113.
If it is desired to terminate operation of the camp
heater 100, the operator will simply close valve 152 which will
terminate fuel flow to the uptube 113. This will then cease
the vaporization of the fuel within the uptube 113 and the
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combustion will terminate.
Instead of the s-tube configuration for the uptube
113 described and illustrated for the burner 141, an r-tube
configuration (not illustrated) could be utilised. The r-tube
configuration has an uptube in which the fuel is vaporized
similarly to the vaporization which takes place in the s-tube
configuration described. However, rather than the vapor
travelling down around the circumference of the uptube, the
uptube is provided with a cap which directs the vapor into a
separate downtube where the vapor exits into the casing where
combustion of the vaporized fuel again occurs.
Rather that the regulator being a zero pressure
regulator, a carburetor may be conveniently used. The use of a
carburetor is particularly attractive where the installation of
the heater 100 is intended to be relatively permanent so that
fuel spillage during transportation is not a principal
consideration.
Many further modifications will readily occur to
those skilled in the art to which the invention relates and the
specific embodiments described should be taken as illustrative
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of the invention only and not as limiting its scope as defined
in accordance with the accompanying claims.
