Note: Descriptions are shown in the official language in which they were submitted.
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HEATING DEVICE HAVING ELECTRIC
AND FUEL POWERED HEAT SOURCES
RELATED APPLICATIONS
This International Application claims the priority of pending U.S..Application
Serial
No. 12/434,271, filed on May 1, 2009
FIELD OF THE INVENTION
The present invention relates generally to heating devices that are capable of
utilizing
either hydrocarbon combustion or electric current as a source of heat
BACKGROUND OF THE INVENTION
There are many portable devices, such as blow dryers and curling irons that
utilize
heat in their operation Portable devices that utilize heat to evaporate or
volatilize
substances are also well known in the prior art Such devices are commonly used
to
dispense insect control active ingredients or air treatment materials, such as
air
fresheners. Users employ these devices in a variety of places, such as in
their
backyards, near swimming pools or patios and the like They also are commonly
toted
as part of hunting or camping gear to be used in the wilderness ¨ usually far
from a
source of electricity
However., prior art devices are limited by the fact that a single source is
utilized to
generate heat ¨ either fuel powered combustion or electrical power. Thus an
electrically powered plug-in device would not be useful for camping/hunting ¨
beyond the range of accessible electric current, and a fuel powered device
would not
be necessary when the device is used around the home with convenient access to
electrical current Thus, each of the prior art systems is adapted for a
limited use
The current invention solves this problem by providing a single device for
volatilizing
substances that is alternatively powered by either a hydrocarbon fuel source
or by
electrical current
It is important for units to be lightweight and easily portable, and the prior
art has
focused on developing streamlined systems Combining two heat sources and their
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corresponding two fuel sources would increase the size, weight and ultimately
the
utility of the unit Moreover, if the two sources were utilized simultaneously
it could
result in temperature control problems and would possibly damage the unit
Thus,
there is a need for a single, lightweight, portable device that produces heat
and which
can be alternatively powered by either electric current or by fuel combustion
according to user's preferences and/or needs
SUMMARY OF THE INVENTION
The current invention addresses these problems by providing a dispensing
device that
is powered by either of two cartridges ¨ an electric cartridge or a fuel
cartridge. The
cartridges are designed to be inserted into the same cavity which has
attachment
means to receive either one The cartridges cannot be inserted or utilized
simultaneously, thus allowing for the device to be streamlined and lightweight
while
supporting dual heating capacities Temperature control issues also are avoided
The invention will be described as it relates to an insect repellant device,
but one of
ordinary skill in the art would recognize that the invention relates broadly
to portable
devices, which are designed to utilize alternative fuel sources
The inventive device includes both a gas-fueled and an electric powered heat
source
by way of a tank connection means that is configured to alternatively receive
either a
fuel tank in gas-tight relation or an electric cartridge for connecting the
device to a
source of electricity. For use as a portable device, a fuel tank is inserted
for providing
fuel for combustion. However, for use as a plug-in device an electric
cartridge is
inserted which is connected to a power supply (adapter) to provide safe, low
voltage
power, thus allowing for the device to be plugged into a standard electrical
outlet For
the purpose of this application, when the device is used in combination with
an
electric cartridge it is in "plug-in mode," whereas when it is used in
combination with
fuel cartridge it is said to be in "portable mode."
Regardless of the heat source ¨ the manner in which volatilizable substances
are
dispensed is fundamentally the same Namely, a conductive heat plate is
provided¨
upon which a mat impregnated with a volatilizable substance is placed. When
the heat
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plate is sufficiently heated ¨ from either heat source ¨ the volatilzable
substances
evaporate and are thereby dispensed
In portable mode, a fuel cartridge is inserted into a tank connection assembly
having a
means for metering fuel fiom the cartridge to a combustion nozzle located
within a
combustion chamber At the combustion nozzle a spark source is provided for
igniting
a fuel/air mixture for combustion
In plug-in mode, instead of inserting a fuel cartridge, an electric cartridge
(referred to
interchangeably herein as an e-cartridge) is inserted The e-cartridge is
adapted to
selectively engage with an electrical connector of the tank connection
assembly A
line cord extending from the e-cartridge to a plug mounted, low voltage
adapter, is
used to plug the device into an electrical socket The device comprises an
electrical
circuit having a heating element Current flowing through the circuit causes
the
heating element to reach a temperature that provides enough heat to the
heating plate
in order to volatilize substances If the heating element is a positive
temperature
coefficient resistor (PTCR) the element will control the heating plate
temperature If
a simple resistance heater is used, the heat input must balance with the heat
loss at the
desired heating plate temperature Alternatively, a thermostat may be provided
to
control the electrical power going to the heating element and so maintain the
desired
heating plate temperature
Embodiments of the invention thus allow for a safe and easy to use device that
is not
limited by the need to be plugged into an electrical receptacle, being instead
entirely
portable for use at any location desired, and can also be plugged into an
electric outlet
for use without a fuel cartridge Furthermore, because a unique cartridge is
inserted
for each use ¨ the device need not carry any fuel while in plug-in mode and
the
external low voltage adapter is removed in portable mode. This allows for a
single
device, which permits a user to select a preferred method of dispensing
substances
that is streamlined and lightweight
BRIEF DESCRIPTION OF THE DRAWINGS
Fig 1 is a top, perspective view of a dispensing unit shown with its top
casing
removed and with an e-cartridge secured therein
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Fig. 2 is a side perspective view of a fuel cartridge according to an
embodiment of the
invention.
Fig 3 is a side perspective view of an e-cartridge according to an embodiment
of the
invention.
Fig. 4 is atop, perspective view of a dispensing unit shown with its top
casing
removed and with an e-cartridge prior to being inserted.
Fig. 5 is an enlarged partial top view of a dispensing unit shown without a
top casing
according to an embodiment of the invention.
Fig. 6 is a cross-sectional partial top view of a dispensing unit with a fuel
cartridge
secured therein according to an embodiment of the invention.
Fig. 7 is a broken away, bottom view of a dispensing unit showing an ignition
circuit
according to an embodiment of the invention.
Fig. 8 is a broken away, bottom view of a dispensing unit showing an ignition
circuit
according to an embodiment of the invention.
Fig. 9 is a schematic view of knob configurations that alternate between "plug
in
mode" and "portable mode" according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will now be described with reference to
the
above-identified Drawings.
Referring to Fig. 1, the mechanical elements of the dispensing device 10 are
enclosed
within a housing. The housing preferably comprises an upper casing (not shown)
and
a lower casing 14. In a preferred embodiment, the device comprises a
dispensing end
38 and a handle 40. The dispensing end 38 contains the heat sources used for
dispensing the volatilizable substances, and the handle 40 is barrel or rod
shaped and
easily fits in the grip of a user. In an embodiment handle 40 comprises a
cavity that is
sized and shaped to accommodate the fuel and electric cartridges - one at a
time. In
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this fashion, the use of the e-cartridge physically prevents the use of the
fuel cartridge
and vice versa
Dispensing end 38 houses a heating plate 16 comprising a thermally conductive
material ¨ such as aluminum, copper or the like ¨ for receiving a mat 60
impregnated
with a volatilzable substance The heating plate 16 is secured atop of the heat
sources
and is in thermal communication therewith As shown, tabs 17 extend from
heating
plate 16 that are adapted to receive a screw or similar fastening device for
securing
heating plate 16 to housing 14 Note that the heating plate in Fig 1 is shown
as being
transparent in order to show the heating sources disposed therebelow. In Fig 4
plate
16 is shown in solid and secured atop of the heat sources.
When either of the heat sources is activated, heat is transferred to the
conductive
plate. The conductive plate 16 reaches a sufficient temperature so as to
dispense a
volatilizable substance in thermal communication therewith
In order to supply constant energy to the heat sources, a fuel cartridge or an
electronic
cartridge must be secured and positioned for dispensing either fuel or
electric current
To that end, a tank connection assembly 18 is disposed in the housing that is
adapted
to alternatively receive a fuel cartridge (shown in Fig 2) or an electrical
cartridge
(shown in Fig. 3). Connection assembly 18 comprises a threaded attachment
means
for threadedly engaging corresponding threads 11 on fuel tank 21. Connection
assembly 18 also is sized and shaped to receive e-cartridge 20 Electric
cartridge 20
comprises an unthreaded engagement portion 22 that slides into the threaded
receiving portion of connection assembly 18 in a fictional relationship.
Referring to Fig. 3, an electric cartridge 20 is shown, which connects to an
AC/DC
converter for converting current to be safe outdoors, and usable in the
heating
element A line cord 30 extends from e-cartridge 20, which when inserted into
an
electric socket allows for current to flow into the AC/DC converter.
Projecting from
e-cartridge 20 is an electrical connector 24 for mating with corresponding
conductive
wires 25 in the device When e-cartridge 20 is engaged with connection assembly
18
and electrical connector 24 is in electrical contact with the internal
electric heating
circuit via wires 25 ¨ current output from the e-cartridge 20 flows to the
heating
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element. Electric cartridge 20, thus serves as a connector, which connects the
internal
wiring of the device to a power. supply via electrical contact
In an embodiment of the invention, the adapter/power supply could be housed
inside
the e-cartridge. In this embodiment, the power cord and connections between
the wall
receptacle and the e-cartridge must be weatherproof and water tight as they
will carry
dangerous current to the e-cartridge It is therefore preferable for the
adapter/power to
be inserted in a wall plug
In one preferred embodiment, and as best shown in Fig 1, a switch 26 is
inserted into
the circuit As such, the flow of elect ic current could be interrupted when
the switch
26 is in the "off" position (i.e. the circuit is broken) In this embodiment,
after
inserting the e-catttidge 20 and plugging into an electrical outlet, the
switch would
need to be moved into the "on" position to complete the circuit and therefore
allow
current flow to the heating element. In one embodiment, a rotatable knob 27
having a
projecting member 29 is provided to turn the switch on or off
Referring to Fig 1, electrical wires 25 are shown, which deliver current to
heating
element 28. Heating elements are known in the prior art and are commonly used
in
portable devices that require heat.
Although substantially any heating element or resistor may be used, in a
preferred
embodiment heating element 28 comprises PICR material PTCR (positive
temperature co-efficient of resistivity) materials are well known in the art
as being
suited for heating purposes This is because as the heat of the material
increases it
becomes increasingly resistant to current and at high enough temperatures it
ceases to
conduct at all As such, PTCR is an excellent self-regulating material that
effectively
shuts off a heat source when it becomes excessively hot, and begins conducting
(and
therefore heating) again after it cools down
Fig 4 is a broken away, partial perspective of some of the mechanical elements
of the
dispensing device. As shown, e-cattridge 20 is aligned with and positioned to
be
inserted into tank connection assembly 18. A line cord 30 (not shown) extends
from
e-cartridge 20 A first end of line cord 30 comprises a low voltage transformer
having
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prongs for inserting into an electrical socket and a second end of' line cord
30 is
inserted into an e-cartridge 30.
As previously described, the dispensing device can be alternatively used in
"plug-in"
or "portable mode.," For use in portable mode, a fuel cartridge containing a
hydrocarbon fuel is inserted into tank connection assembly 18. Tank connection
assembly 18 comprises a threaded receiving area for threadedly engaging
corresponding threads on the fuel cartridge. Bayonet, snap and other
alternatives to
threaded engagement will be apparent to one of ordinary skill in the art and
are within
the scope of the invention.
In portable mode, combustion supported by air and gas mixture is utilized to
supply
heat to the heating plate 16 In this embodiment, a hydrocarbon fuel source is
utilized
for dispensing volatilizable substances according to the teachings of U S
Patent No.
4,699,123, U S Patent No 4,759,343 and U S Patent No 4,815,441 ¨ each of which
is incorporated by reference herein. Note that the incorporated patents
describe a two-
burner system, whereas in the current invention a single burner system is
utilized as
described in U S. Patent No 5,700,430 and incorporated by reference herein in
its
entirety.
Fig 6 shows a cross-sectional view of a dispensing unit with a fuel cartridge
21 that is
secured in connection assembly 18 and positioned to dispense gas. A fuel
metering
device or system is provided for metering gas For example, a valve activator
system
is provided to control the release of gas flora cartridge 21 In one preferred
embodiment, and as shown in Fig 6, the valve activator system comprises a
plunger
23 having one pointed end 25 that is utilized to depress a fuel cartridge
valve and a
second end that is connected to a spring which exerts a biasing force
thereupon When
cartridge 21 is inserted and secured in assembly 18, plunger 23 is pushed
downward
(toward the cartridge) by the attached biasing spring (not shown) thereby
opening the
cartridge valve and permitting gas to flow therefrom. Thereafter, pressure
exerted
from escaping gas builds up to apply a counter force to plunger 23. Eventually
the
pressure ftom escaping gas overcomes the pressure exerted by the spring, and
the
pressure build-up pushes the plunger off of the cartridge valve, thereby
terminating
supply. Once the gas pressure diminishes and there is no counter pressure on
the
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spring ¨ the plunger is forced into the valve once again to permit gas flow.
This
allows for an effective gas regulating system
Fuel flowing from the fuel cartridge is delivered to a venttni tube 31, which
has an
opening 61 for the intake of air thus creating a fuel/air mixture. The
fuel/air mixture is
accelerated into a combustion nozzle 34 (as shown in Fig.1) In one embodiment,
a
hydrocarbon fuel line 35 (best seen in Figs 7 and 8) carrying a fuel/ab
mixture passes
below or around heating element 28 to reach the combustion chamber 33 located
above it It will be understood by one of skill in the art that the two heat
sources may
positioned in any of various configurations such as side by side or separated
from one
another. In other embodiments of the invention, two separate heating plates
are
provided ¨ one disposed above, and in thermal communication with, the electric
heating element 28 and the other above and in thermal communication with the
combustion chamber 33.
Combustion chamber 33 comprises an ignition system for initiating hydrocarbon
combustion. Referring to Fig 7, a pair of electrode wires 39 is provided,
which
emanate from a piezoelectric device 37. One wire 39a has a first end, which
emanates
from piezoelectric device 37 and terminates in contact with heating plate 16
Another
wire 396 emanating from piezoelectric device 37 terminates in close proximity
to
combustion nozzle 34 Combustion nozzle is in contact with heating plate 16 and
is
therefore in electrical contact with wire 39a As such, there is provided an
ignition
circuit that is complete except for a gap between terminal end of wire 39b and
combustion nozzle 34. When the piezoelectric device 37 is activated, a spark
jumps
from the terminal end of wire 39b to combustion nozzle 34, thereby completing
the
ignition circuit In a preferred embodiment, piezoelectric device 37 is
activated by an
ignitor button 41, which when pressed by a user activates piezoelectric device
37
The two different heat sources are each utilized to the exclusion of the other
In plug-
in mode, heating element 28 is exclusively utilized as a heat source, whereas
in
portable mode, combustion nozzle 34 is exclusively utilized Both heat sources
are
situated beneath heating plate 16 (Fig. 1) and supply heat to the same
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Thus, a separate cartridge is provided for each use, and a user must change
cartridges
(from fuel to e-cartridge and vice versa) when switching between plug-in and
portable
modes Moreover, the device is adapted to receive only one cartridge at a time.
This
prevents a user from simultaneously using both heat sources ¨ which would
cause
temperature control problems. This configuration additionally allows for the
device to
have the same dimensions as previous models ¨ allowing it to remain
lightweight and
compact ¨ yet with dual heating capacities. Furthermore, fuel cartridges that
have
been popularized for use with previous dispensing devices made by the instant
assignee may be used in the current dual powered device.
In one embodiment of the invention, and as shown in Fig. 5, a switch mechanism
is
provided for enabling/disabling gas flow from cartridge 21, thereby serving as
an
"on" and "off' switch. As shown, a lever 40 is attached to plunger 23
substantially
orthogonally thereto A first end 41 of lever 40 is pivotably connected to the
dispensing device, for example by way of pivot 42 In this configuration
plunger 23 is
not inhibited by pivoting lever 40 and it is therefore free to move toward and
away
from cartridge 21 as described above However, lever 40 can be immobilized to
suppress movement of plunger 23 and therefore prevent gas flow from cartridge
21.
For example, as shown in Fig 5, knob 27 is provided with a projecting arm 44,
which
terminates in close proximity to the second end 43 of lever 40 Knob 27 is
rotatable to
position arm 44 in contact with lever 40 (clockwise in the illustration). Arm
44 thus
presents as a physical barrier to the movement of lever 40 When lever 40 is
thusly
immobilized, attached plunger 23 also is immobilized and incapable of lowering
toward cartridge 21 in order to depress the cartridge valve This provides for
an
effective "off' switch when the device is used in portable mode
In another embodiment of the invention, in plug-in mode, instead of using an e-
cartt idge as described herein, the device is adapted to receive a standard
power cord
as is well know in the art In order to maintain safety and proper temperature
control,
the device is adapted to allow only one heat source to be used at a time For
example,
referring to Fig 9, a power jack 50 is provided for receiving a power cord and
is
positioned near a switch knob 52. Flanges Ma, 54b on switch knob 52 prevents
switch knob 52 from rotating to the gas "on" position when the power jack is
in place
As shown in Fig 9 (position A) an opening defined by flanges 54a and 54b
allows for
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the insertion of a power cold into power jack 50 When the power cord is so
inserted,
it presents a physical battier to flange 54a and 54b and does not allow any
significant
movement of switch knob 52 This prevents knob 52 from rotating to the gas "on"
position when the power cord is in place Similarly, the flanges 54 prevent the
insertion of a power jack when the switch is in the gas on position (position
C) As
shown, when knob 52 is rotated to the gas "on" position, one of the flanges
(54a in the
illustration) covers power jack 50, thereby preventing the insertion of a
power cord
when the gas function is "on.,"
Referring to Fig 5, a grill 36 is shown disposed above the heat sources 28, 34
In use,
a mat 60 is inserted in the underside of grill 36 the mat thus being in
thermal contact
with the heating plate 16 therebelow and protected by the grill 36 thereabove.
Grill 36
comprises slots 62, which allows for volatilized substances to escape
Having described this invention with regard to specific embodiments, it is to
be
understood that the description is not meant as a limitation since further
modifications
and variations may be apparent or may suggest themselves to those skilled in
the art
It is intended that the present application cover all such modifications and
variation as
fall within the scope of the appended claims For example, it will be
understood by
those of ordinary skill in the art that the dual power sources taught in by
the current
invention can be applied to other devices such as curling irons, blow dryers,
power
tools and the like as well as to other heating devices
