Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a soldering iron and,
more particularly, to a portable, gas powered soldering
iron. Conventional, resistance-heated soldering irons
have known limitations such as: heat-up time, inconvenient
electrical cord, limited heating capacity, inductive
properties and potential spark generation.
In the present invention a soldering iron is
provided which is small and convenient to use yet having
variable heat capabilities, virtually instant heat, fully
portable and spark-free which is essential when used
to solder ICs. The soldering iron of the present invention
has a soldering element tip which is initially heated by a
gas-burning flame and subsequently by a gas fed ca-talytic
combustor. The flow of gas to the combustion zone may be
regulated so as to provide control of the heat generated at
the element tip.
According to a broad aspect of the presen-t
invention there is provided a gas powered, pencil-shaped,
soldering iron suitable for positioning a pocket of an
article of clothing. The gas powered soldering iron comprises
a fuel reservoir having a nozzle secured thereto with conduit
means. Control means is attached to the reservoir to control
fuel flowing therefrom into the conduit means. Venturi means
is secured in front of the conduit means and spaced therefrom
whereby fuel from the conduit means is focused in an axial
opening of the venturi means and mixed with air internally of
the soldering iron. A combustion chamber is disposed at the
end of a transfer tube which is adapted to caxry a jet-stream
of fuel/air mixture to the combustion chamber. A catal ~ic
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combustor of porous material is disposed in the combustion
chamber. The combus-tor is adapted to burn in combination
with the air/fuel mixture. A soldering element is attached
to the combustion chamber and arranged to be hea-ted by combus-
tion in the combustion chamber. Focusing means is associated
with -the combustion chamber to focus the flame onto an end of
the soldering element during initial combustion, and wherein
the flame gradually extinguishes as the catalytic combustor
begins to burn.
The soldering iron will now be described in greater
detail wi-th reference to the appended illustrations wherein:
Figure 1 is a cross-sectional view of the soldering
iron;
Figure 2 illustrates the combustion chamber;
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Figure 3 is an expanded view of the vaporizer-
control valve handle;
Figure 4 is an expanded view of the combustor;
Figure 5 illustrates a second embodiment wherein
the cap is retractable, and
Figure 6 shows an alternate handle co~figuration.
DETAILE~ DESCRIPTION
As illustrated in Figure 1, the soldering iron of
the present invention includes a fuel reservoir 15. The
reservoir 15 shown as a hollow cylinder includes a filler-
opening 16. The opening 16 is a spring-loaded, one-way
valve which permits entry of the liquid fuel to the reservoir.
Although several types of liquid fuel may be used, it is
contemplated by the present in~ention that the fuel is
butane, or the like, which is readily available in containers
for use in filling cigarette lighters in a manner well known
in the art. Although not specifically described it is to be
understood that reservoir 15 may be replaced by a throw-away
type fuel cartridge available commercially.
The opposite end of the reservoir is provided with
a wick 13 which serves to oonduct the fuel in a liquid state
to opening 18. A regulator or control valve 19 is provided
in opening 18 for the purpose of controlling the quantity of
fuel which is permitted to flow out of the reservoir. The
regulator valve acts as a vaporizer as is well known in the
art and changes the fuel from a liquid state to a gaseous
form. The amount of gaseous fuel exiting from the reservoir
is regulated by the control valve which may be va`ried from a
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fully closed to a fully open position. The control valve
is activated by handle 20 which extends to the outside of
the soldering unit.
A nozzle 21 having a diameter of approximately
0.002" to 0.003" focuses the fuel passing through the
control valve 19 into venturi 22. Venturi 22 formed of
heat resistant material such as bakelite or the like, fits
over end 23 of reservoir 15 and handle 20 of control valve
19 projects through a slot 2~ therein. Venturi 22 has a
central axial opening 25 having a diameter between 0.05"
and 0.07" and, more particuarly, 0.06".
As the fuel flows through venturi opening 25 air
is drawn into the stream where they mix prior to being
injected into transfer tube 30. Transfer tube 30, made of low
heat conducting material, directs the fuel/air mixture into
the combustion chamber 31. The combustion chamber 31,
constructed of heat resistant and high heat conducting
material, fits over the transfer tube 32. The opposite
end 33 of the combustion chamber is cone shaped having
2Q openings 34 suitably located. The cone end 33 has an
axial opening 35 therethrough, the opening being threaded so
as to receive soldering element 36 therein. Soldering element
36 has at one end a threaded portion 37 adapted to threadably
engage threaded opening 35. The opposite end 38 of soldering
element 36 has a wedge or similar shaped tip which is parti-
cularly suited for use in a soldering operation.
The combustion chamber 31 contains a catalytic
combustor 40O The combustor 40 is made of high temperature
material such as ceramic or asbestos in a cloth-like format
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impregnated with a known catalytic materia], such as platinum
or palladium. The combustor 40, being cloth-like, is porous
thus permitting the gas~air mix~ure to flow through. In the
present case the combustor is encased in a stainless wire
mesh.
The outer surface of the venturi, the transfer
tube and the combustion chamber, as shown in the illustration,
are tubular, although it is understood that other shapes may
be used. In the present case the outer surface of venturi 22
is provided with a step 41 which receives and holds by friction
fit, cap 42. Cap 42, also tubular, covers the transfer tube,
combustion chamber and element when not in use. The cap 42
also includes a flint and friction wheel 43 well known in the
art as an igniter for cigarette lighters and the like. Since
the soldering iron in a preferred embodiment is comparable in
size to a fountain pen, it may conveniently be earried in a
shirt or jaeket poeket. Aeeordingly, elip 44 may also be
ineluded as part of cap 42.
The cap 42 illustrated in Figure 1 is intended to
be removed to expose element tip 38 for soldering purposes.
It is also contemplated that the cap may be eonstrueted as
shown in Figure 5 such as the main body 50 remains permanently
attached to the unit and end 51 retraets telescopieally into
the body 50 to expose the soldering element tip 38.
When it is desired to use the soldering iron
aeeording to the present invention fuel is added to the
reservoir if neeessary. With the eap attaehed to the unit,
the control handle of the regulator valve is aetivated to
permit flow of the fuel. The igniter is aetivated whieh
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results in combustion of the fuel~air mixture in the
combustion chamber. Initially, the fuel/air mixture will
burn and a flame will be observed. The flame is directed
onto threaded end 37 of the soldering element which, being
highly heat conductive, causes element tip 38 to be heated
almost instantly. Gradually, the catalytic combustor is
heated by the flame and it will begin to burn as is known
in the art. As more and more of the catalytic combustor
burns less of the gas/air mixture will pass through the
lQ combustor and the flame will gradually extinguish. Eventually,
the entire combustion is contained within the ca-talytic com-
bustor. The cap may be removed shortly after ignition. It
is to be noted that the cap has an exhaust opening 48 which
prevents pressure buildup therein. After the cap is removed
the tip is sufficiently hot to commence soldering.
As illustrated in the drawings, end 37 of element
36 is in direct contact with the catalytic combustor. Thus,
after the flame is extinguished the element is heated by
flameless combustion within the combustor. The element
which is made of high temperature, heat conducting material,
is heated by radiation and the heat is rapidly conducted to
the wedge or tip. An element made of copper-chrome alloy
and nickle plated has been used with success. The walls of
the combustion chamber are also heated by conduction from
the combustor and this heat, which reaches the cone end of
the combustion chamber, is concentrated through the threaded
opening directly to the soldering element. Thus, the element
and, consequently, the tip, is heated through both the
conduction and radiation. Openings in the cone end permit
the exhaust created by combustion to escape.
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By regulating the fuel flow by means of the
control valve, the combustion temperature and the temperature
of the soldering element may be varied. In practice, the
combustor holds sufficient heat that the fuel valve may be
shut off completely for a short period of time and will
reignite when the fuel is turned on again. Additionally,
it is easy to control combustion at a minimum level with
the catalytic combustor.
In the embodiment illustrated in Figures 1 to 5,
the unit is cylindrical in shape comparable to a fountain pen
or similar object. Figure 6 illustrates a further embodiment
wherein the handle and fuel reservoir combination are shaped
like the handle of a conventional soldering gun. This embodi-
ment is suited for larger soldering operations where higher
heat a larger fuel capacity are desired.
