U.S. patent application number 13/085979 was filed with the patent office on 2014-07-31 for forced air heater including on-board source of electric energy.
This patent application is currently assigned to Enerco Group, Inc.. The applicant listed for this patent is Dennis O'Toole, Brian S. Vandrak. Invention is credited to Dennis O'Toole, Brian S. Vandrak.
Application Number | 20140209085 13/085979 |
Document ID | / |
Family ID | 65236779 |
Filed Date | 2014-07-31 |
United States Patent
Application |
20140209085 |
Kind Code |
A9 |
Vandrak; Brian S. ; et
al. |
July 31, 2014 |
Forced Air Heater Including On-Board Source of Electric energy
Abstract
A heating device may comprise a control assembly having a
self-contained, on board power supply. A control unit may control
the operation of the heater and the power supply may comprise a
first power source in electrical communication with the control
unit, wherein the control unit controls the operation of the first
power source to selectively supply electrical power to at least a
portion of the heating device; and, a second power source in
electrical communication with the control unit, wherein the control
unit controls the operation of the second power source to
selectively supply electrical power to at least a portion of the
heating device.
Inventors: |
Vandrak; Brian S.; (Highland
Heights, OH) ; O'Toole; Dennis; (Rocky River,
OH) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Vandrak; Brian S.
O'Toole; Dennis |
Highland Heights
Rocky River |
OH
OH |
US
US |
|
|
Assignee: |
Enerco Group, Inc.
Cleveland
OH
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20110265779 A1 |
November 3, 2011 |
|
|
Family ID: |
65236779 |
Appl. No.: |
13/085979 |
Filed: |
April 13, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11954704 |
Dec 12, 2007 |
8068724 |
|
|
13085979 |
|
|
|
|
61323997 |
Apr 14, 2010 |
|
|
|
60874427 |
Dec 12, 2006 |
|
|
|
Current U.S.
Class: |
126/93 |
Current CPC
Class: |
H02J 7/0068 20130101;
F24H 9/02 20130101; F24H 9/06 20130101; F24H 9/2085 20130101; Y02B
30/00 20130101; F24H 3/025 20130101; Y02B 30/28 20130101; F24H
3/0417 20130101; F24H 3/0488 20130101 |
Class at
Publication: |
126/93 |
International
Class: |
F24C 5/14 20060101
F24C005/14 |
Claims
1. A heating device comprising: a housing assembly having a
combustion region disposed therein; a motor operatively connected
to a fan blade, wherein operation of the motor causes the rotation
of the fan blade to draw ambient air through an air intake end of
the housing assembly and at least a portion of the ambient air is
directed into the combustion region; a fuel assembly comprising: a
fuel tank suitable for containing a liquid fuel; a burner assembly,
wherein the burner assembly is in fluid communication with the fuel
tank and allows the liquid fuel to be communicated from the fuel
tank and mixed with air to form an air/fuel mixture and the
air/fuel mixture is communicated through the burner assembly and
into the combustion region; an ignition system, wherein operation
of the ignition system causes the combustion of the air/fuel
mixture within the combustion chamber resulting in a heated air and
the rotation of the fan blade to direct at least a portion of the
ambient air into the combustion region results in the heated air
being expelled out of a discharge end of the housing assembly; a
control assembly comprising: a control unit for controlling the
operation of the heating device; and, a power supply, wherein the
power supply comprises: a first power source in electrical
communication with the control unit, wherein the control unit
controls the operation of the first power source to selectively
supply electrical power to at least a portion of the heating
device; a second power source in electrical communication with the
control unit, wherein the control unit controls the operation of
the second power source to selectively supply electrical power to
at least a portion of the heating device.
2. The heating device of claim 1, wherein the first power source
comprises a rechargeable battery integral to the heating device
and, the heating device further comprises: a recharging unit
integral to the heating device, wherein the recharging unit is in
electrical communication with the rechargeable battery and the
control unit and the control unit controls the recharging unit to
cause the selective recharging of the rechargeable battery.
3. The heating device of claim 1, wherein the first power source
comprises a selectively removable rechargeable battery and, the
heating device further comprises: a recharging unit, wherein the
rechargeable battery can be selectively placed in electrical
communication with the recharging unit to cause the recharging of
the rechargeable battery.
4. The heating device of claim 3, further comprising: a third power
source, wherein the third power source comprises a second
selectively removable rechargeable battery; and, a storage
compartment attached to the forced-air heater, wherein the storage
compartment is suitable to store the third power source and the
recharging unit.
5. The heating device of claim 1, wherein the first power source
comprises a rechargeable battery and, the heating device further
comprises: a recharging unit, wherein the recharging unit can be
selectively operatively connected to the control assembly to be in
electrical communication with the rechargeable battery and the
control unit and the control unit controls the recharging unit to
cause the selective recharging of the rechargeable battery and the
recharging unit and the rechargeable battery can be selectively
removed from the heating device to enable the recharging of the
rechargeable battery separate from the heating device.
6. The heating device of claim 1, further comprising: a third power
source, wherein the first power source and the third power source
comprise rechargeable batteries that can be selectively
interchanged to enable the extended operation of the heating
device.
7. The heating device of claim 1, further comprising: a third power
source, wherein the first power source and the third power source
comprise rechargeable batteries that can be selectively positioned
in parallel to enable the extended operation of the heating
device.
8. The heating device of claim 1, further comprising: a plug
suitable for conducting electrical power to the heating, wherein
the second power source comprises an external power supply and the
plug can be selectively engaged with the external power supply to
supply electrical power to the heating device.
9. The heating device of claim 8, wherein the external power supply
comprises an AC power source.
10. The heating device of claim 8, wherein the external power
supply comprises a DC power source.
11. The heating device of claim 1, wherein the first power source
comprises a rechargeable battery and the control assembly further
comprises: a charge management unit to prevent overcharging or
over-discharging of the rechargeable battery.
12. The heating device of claim 11, wherein the charge management
unit comprises: an ambient temperature compensation module.
13. The heating device of claim 11, wherein the charge management
unit further comprises: a battery management module, wherein the
battery management module prevents power from being supplied from
the rechargeable battery upon determining that the rechargeable
battery has attained a predetermined level of discharge.
14. The heating device of claim 13, wherein the battery management
module comprises: a battery indicator to indicate a status of the
rechargeable battery.
15. The heating device of claim 1, wherein the control assembly
further comprises: an output actuator operatively connected to the
control unit, wherein the output actuator can be actuated by an
associated user to vary an amount of heat outputted by the heating
device.
16. The heating device of claim 1, wherein the control unit can
control the motor to vary the speed of the fan blade to control the
flow of the ambient air into the housing assembly.
17. The heating device of claim 16, wherein the control unit
determines a current value of fuel intake or heat output and
controls the motor to vary the speed of the fan blade based at
least partially on the determined value of fuel intake or heat
output of the heating device.
18. The heating device of claim 16, wherein the control unit
determines a first temperature and controls the motor to vary the
speed of the fan blade based at least partially on the first
temperature in order to cause the first temperature to comprise a
predetermined target temperature.
19. The heating device of claim 1, wherein the heating device
comprises a dual fuel heater that allows the heating device to
operate utilizing propane and natural gas interchangeably.
20. The heating device of claim 1, wherein the control assembly
further comprises: a thermostat, wherein the thermostat enables an
associated user to control an output of the heating device.
21. The heating device of claim 20, wherein the thermostat is in
electrical communication with the control unit via a first
conductor that allows the associated user to remotely control the
output of the heating device.
22. The heating device of claim 20, wherein the thermostat
comprises: a transceiver portion in electrical communication with;
and, a remote actuator portion, wherein the remote actuator portion
transmits a wireless signal that can be received by the transceiver
portion to remotely control the output of the heating device.
23. The heating device of claim 22, wherein the first power source
comprises a rechargeable battery and the thermostat is at least
partially powered by rechargeable battery.
24. The heating device of claim 1, wherein the first power source
comprises a battery and the second power source comprises a
thermo-electric generator.
25. The heating device of claim 1, further comprising: a plug,
wherein the plug comprises a electrical conductor suitable to
enable the heating device to be at least partially powered by an
external power source.
26. The heating device of claim 25, wherein the external power
source comprises an AC power source.
27. The heating device of claim 25, wherein the external power
source comprises a DC power source.
28. The heating device 25, wherein the first power source
comprises: a rechargeable battery, wherein the external power
source supplies power to recharge the rechargeable battery while
operating the heating device.
29. The heating device of claim 28, wherein the control assembly
further comprises: a power source selector that allows power to be
selectively supplied by the first power source, the second power
source, and the external power source.
30. The heating device of claim 1, wherein the control assembly
further comprises: a power source selector that allows power to be
selectively supplied by the first power source and the second power
source.
Description
[0001] This application claims priority to U.S. Ser. No.
11/954,704, titled Forced Air Heater Including On-Board Source of
Electric Energy, filed Dec. 12, 2007, which is incorporated herein
by reference, which claims priority to provisional application U.S.
Ser. No. 60/874,427, titled Forced Air Heater Including On-Board
Source of Electric Energy, filed Dec. 12, 2006, which is
incorporated herein by reference. This application also claims
priority to U.S. Ser. No. 61/323,997, titled Forced Air Heater
Including On-Board Source of Electric Energy, filed Apr. 14, 2010,
which is incorporated herein by reference.
I. BACKGROUND
[0002] A. Field of Invention
[0003] This invention relates generally to portable forced-air
heaters, and more particularly to portable forced-air heaters that
derive at least a portion of their electric energy required for
operation of the heaters, or an accessory thereof, from an on board
source.
[0004] B. Description of the Related Art
[0005] Fuel-fired portable heaters such as forced-air heaters are
well known in the art and find use in multiple environments. The
heater typically includes a cylindrical housing with a combustion
chamber disposed coaxially therein. A combustible liquid fuel from
a fuel tank is atomized and mixed with air inside the combustion
chamber where it is combusted, resulting in the generation of a
flame. During combustion of the air/fuel mixture a fan blade is
rotated by an electric motor to draw ambient air into the heater to
be heated by the combustion of the air/fuel mixture. The heated air
is expelled out of the heater by the continuous influx of air
caused by the fan.
[0006] Traditionally, forced-air heaters have required a source of
electric energy to energize the motor that rotates the fan blade
and optionally to operate an ignition source that triggers
combustion of the air/fuel mixture. The fan is often a heavy-duty,
high output fan that consumes significant amounts of electrical
energy during operation thereof, and operation of the igniter
consumes even more electrical energy. The demand for electrical
energy created by operation of the fan and other electrical
components of forced-air heaters has required such heaters to be
plugged into a conventional wall outlet supplying alternating
current ("AC") electrical energy generated by a public utility. In
remote environments a lengthy extension cord can establish a
conductive pathway for the electrical energy between a wall outlet
and the location of the forced-air heater. However, at locations
where a new structure is being built a conventional wall outlet is
typically not available, requiring the use of a portable generator
to supply the electrical energy until utility-generated electrical
energy becomes available.
[0007] As previously mentioned, forced-air heaters are often
utilized to provide heat to new construction environments for
significant periods of time that can extend well into the night.
After dusk, illumination of the environment in the vicinity of the
forced-air heater is required to enable workers to view their
worksite and avoid potentially hazardous conditions. Assuming that
a conventional wall outlet is available, an extension cord can be
used to conduct electrical energy from the wall outlet to an
on-site light stand. However, the light stand adds to the equipment
that must be transported to a jobsite, and a conventional wall
outlet is usually not available during the initial stages of a new
construction.
[0008] Even in instances when a conventional wall outlet is
available, there are normally a limited number of electrical
devices that can be powered by the outlet at any given time. Using
adaptors to increase the number of available outlets into which an
electrical device can be plugged can lead to excessive currents
being drawn through an extension cord or other adaptor. Thus, there
are a limited number of electrical devices that can be
simultaneously powered on a new construction jobsite at any given
time. This limitation is even greater when a wall outlet supplying
utility-generated electricity is unavailable.
[0009] Forced-air heaters are also relatively bulky, and occupy a
significant amount of storage space while not in use. Attempts to
store such a heater in an alternative orientation other than its
intended operational orientation in which the heater is designed to
be fired in order to conserve storage space results in the liquid
fuel leaking out of the heater. And although the fuel can be
drained from the heater before storing it in an alternative
orientation to minimize the leakage of fuel, such an option is time
consuming, and is impractical for temporary storage on a daily
basis.
II. SUMMARY
[0010] According to one embodiment of the invention, a heating
device comprises a housing assembly, a motor, a fuel assembly, and
a control assembly. The housing assembly may comprise a combustion
region disposed therein. The motor may be operatively connected to
a fan blade. The operation of the motor may cause the rotation of
the fan blade to draw ambient air through an air intake end of the
housing assembly and at least a portion of the ambient air is
directed into the combustion region. The fuel assembly may comprise
a fuel tank suitable for containing a liquid fuel, a burner
assembly, and an ignition system. The burner assembly may be in
fluid communication with the fuel tank and may allow the liquid
fuel to be communicated from the fuel tank and mixed with air to
form an air/fuel mixture and the air/fuel mixture is communicated
through the burner assembly and into the combustion region. The
operation of the ignition system may cause the combustion of the
air/fuel mixture within the combustion chamber resulting in a
heated air and the rotation of the fan blade to direct at least a
portion of the ambient air into the combustion region results in
the heated air being expelled out of a discharge end of the housing
assembly. The control assembly may comprise a control unit for
controlling the operation of the heating device and a power supply.
The power supply may comprise a first power source and a second
power source. The first power source may be in electrical
communication with the control unit, wherein the control unit
controls the operation of the first power source to selectively
supply electrical power to at least a portion of the heating
device. The second power source may be in electrical communication
with the control unit, wherein the control unit controls the
operation of the second power source to selectively supply
electrical power to at least a portion of the heating device.
[0011] Still other benefits and advantages of the invention will
become apparent to those skilled in the art to which it pertains
upon a reading and understanding of the following detailed
specification.
III. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The invention may take physical form in certain parts and
arrangement of parts, a preferred embodiment of which will be
described in detail in this specification and illustrated in the
accompanying drawings which form a part hereof and wherein:
[0013] FIG. 1 is a perspective view of a forced-air heater
including an onboard power supply, an outlet, and a light exposed
to an exterior of the forced-air heater in accordance with an
embodiment of the present invention;
[0014] FIG. 2 is a perspective view of a forced-air heater
including an onboard power supply, an outlet, and a light exposed
to an exterior of the forced-air heater in accordance with an
embodiment of the present invention;
[0015] FIG. 3 is a cutaway view of a forced-air heater having an
onboard power supply in accordance with an embodiment of the
present invention;
[0016] FIG. 4 is a perspective view of a forced-air heater
including an onboard power supply in accordance with an embodiment
of the present invention;
[0017] FIG. 5 is an assembly view of a forced-air heater including
an onboard power supply in accordance with an embodiment of the
present invention;
[0018] FIG. 6 is an illustrative view of a forced-air heater
including an onboard power supply in accordance with an embodiment
of the present invention;
[0019] FIG. 7 is a cutaway view of a battery that can optionally be
utilized as a portable power source for a forced-air heater in
accordance with the present invention;
[0020] FIG. 8 is a view of a forced-air heater in an orientation in
which it is to be fired according to an embodiment of the present
invention;
[0021] FIG. 9 is a view of a forced-air heater in an orientation in
which it can optionally be transported with minimal leakage of a
liquid fuel from the heater's fuel tank according to an embodiment
of the present invention;
[0022] FIG. 10 is a view of a forced-air heater in a
substantially-vertical orientation in which it can optionally be
stored with minimal leakage of a liquid fuel from the heater's fuel
tank according to an embodiment of the present invention;
[0023] FIG. 11 is a cutaway view of a fuel management system that
can optionally be provided to a forced-air heater according to an
embodiment of the present invention;
[0024] FIG. 12 is an illustrative view of a control panel for a
heating device according to one embodiment of the invention;
[0025] FIG. 13 is a perspective view of a radiant heater including
an onboard power supply in accordance with an embodiment of the
present invention;
[0026] FIG. 14 is a perspective view of a radiant heater including
an onboard power supply in accordance with an embodiment of the
present invention;
[0027] FIG. 15 is a cutaway view of a radiant heater including an
onboard power supply in accordance with an embodiment of the
present invention;
[0028] FIG. 16 is a cutaway side view of a radiant heater including
an onboard power supply in accordance with an embodiment of the
present invention;
[0029] FIG. 17 is a top perspective view of a radiant heater
including a motor and fan blades positioned in the housing assembly
and operated by an onboard power supply in accordance with an
embodiment of the present invention;
[0030] FIG. 18 is a rear elevational view of a radiant heater
including an onboard power supply showing a detachable door for
enclosing a fuel tank in accordance with an embodiment of the
present invention; and,
[0031] FIG. 19 is a rear elevational view of the radiant heater
shown in FIG. 18 wherein the detachable door is removed thereby
illustrating the fuel tank which is pivotable about a fuel supply
connection in accordance with an embodiment of the present
invention.
IV. DETAILED DESCRIPTION
[0032] Certain terminology is used herein for convenience only and
is not to be taken as a limitation on the present invention.
Relative language used herein is best understood with reference to
the drawings, in which like numerals are used to identify like or
similar items. Further, in the drawings, certain features may be
shown in somewhat schematic form. Referring now to the drawings
wherein the showings are for purposes of illustrating embodiments
of the invention only and not for purposes of limiting the same,
the FIGURES show a heating device 1 having a self-contained,
onboard power supply 24. The heating device 1 may comprise a
portable heating device suitable for use in recreational
enclosures, temporary work enclosures, as well as other
environments wherein a portable supply of heat is desired or
useful. Although a specific type or types of heating devices may be
described, the type of heating device utilizing the on-board power
supply 24 is not intended to be a limitation of the invention. The
on-board power supply 24 may be utilized with any type of heating
device chosen with sound judgment by a person of ordinary skill in
the art.
[0033] With reference now to FIGS. 1-5, according to one
embodiment, the heating device 1 may comprise a forced-air heater
having a housing assembly 9, a fuel assembly 17, and a control
assembly 22. The housing assembly 9 may provide a stable base for
the heating device 1 and may provide a storage area for one or more
power sources, a recharging unit, fuel lines or hoses, or power
cords as further described below. In one embodiment, the housing
assembly 9 may comprise a base adjustment mechanism 47 that allows
for variation in the direction (i.e., allows for the rotational
movement of the housing assembly 9), height and/or pitch of the
heating device 1. The housing assembly 9 may comprise an outer
cylinder 11, an inner cylinder 12, a support 5, a motor 15, and fan
blades 18. The outer cylinder 11 may be designed to at least
partially protect the interior components of the forced-air heater
1 and may comprise a generally cylindrical shell that is positioned
substantially around the inner cylinder 12. The outer cylinder 11
may comprise a lower housing portion 7 and an upper housing portion
8. In one embodiment, the upper and lower housing portions 7, 8 may
comprise separate portions that are fixedly attached to form a
generally cylindrical shell. In another embodiment, the outer
cylinder 11 may comprise a singular, substantially cylindrical
shell that comprises the upper and lower portions 7, 8. The inner
cylinder 12 may also comprise a generally cylindrical shell having
a first or air intake end 19 and a second or discharge end 2. The
inner cylinder 12 may be positioned substantially coaxially within
the outer cylinder 11 to define an annular space 71 therebetween.
The annular space 71, shown in FIG. 3, may comprise a cavity
defined by or formed between the outer cylinder 11 and the inner
cylinder 12 and may result in a reduction of the amount of heat
that is transferred therebetween relative to the amount of heat
that would be so transferred if the outer cylinder 11 contacted the
inner cylinder 12. In one embodiment, the housing assembly 9 may
comprise an insulator, not shown, positioned at least partially
within the annular space 71. The insulator, not shown, may reduce
the amount of air necessary to flow through the annual space 71 to
cool the outer cylinder 11. In another embodiment, the housing
assembly 9 may be designed to reduce the required air flow to the
burner assembly 23 thereby resulting in a reduction in the power
required to operate the heating device 1.
[0034] With continued reference now to FIGS. 1-5, according to one
embodiment, the inner cylinder 12 may be secured to the outer
cylinder 11 by a plurality of evenly spaced brackets disposed about
the periphery of the ends of the inner cylinder 12. The brackets
may be secured by conventional fasteners such as screws or the like
to the inner cylinder 12 and to corresponding locations on the
outer cylinder 11. At least a portion of the recess or area defined
by the inner cylinder 12 may comprise a combustion region 10 as
further described below. In one embodiment, a semi-spherical shaped
baffle 13 may be provided adjacent to the discharge end 2 of the
inner cylinder 12 and an inner cylinder assembly 33 may be provided
adjacent to the air intake end 19. An air intake guard 14 may be
attached to the end of the outer cylinder 11 adjacent to the air
intake end 19 of the inner cylinder 12. The air intake guard 14 may
prevent large objects, which can damage fan blades 18 or block the
air passages, from entering the housing assembly 9. The intake
guard 14 may also protect the operator from injury resulting from
coming into contact with rotating fan blades 18. In one embodiment,
the housing assembly 9 may comprise a safety grill 41 that
substantially performs the functions of the air intake guard 14 and
the inner cylinder assembly 33. The safety grill 41 may
substantially cover the air intake end 19 and fan blades 18 thereby
allowing the housing assembly 9 to utilize a single grill or guard
unit. In one embodiment, a handle 35, shown in FIGS. 3 and 4, may
be attached to the upper housing portion 8 to assist the operator
in transporting the heating device 1.
[0035] With continued reference now to FIGS. 1-5, according to one
embodiment, the support 5 may be attached to the housing assembly
9. In one embodiment, the support 5 may act as a base for the
heating device 1, shown in FIG. 4. In another embodiment, the
support 5 may be attached to the housing assembly 9 and the fuel
tank 3, shown in FIGS. 1-3. The support 5 may be secured to or
otherwise formed adjacent to the top surface of the fuel tank 3 by
spot welding, brazing, or the like, and may support the housing
assembly 9. The support 5 may include at least one adjustable panel
6 that can be adjusted by an operator to form or reveal a support
aperture 30. The support aperture 30 may allow the operator to gain
access into an interior chamber 21 defined by the support 5. The
adjustable panel 6 may be secured to the support 5 by any type of
fastener that permits adjustment of the adjustable panel 6 to allow
access into the interior chamber 21 chosen with sound judgment by a
person of ordinary skill in the art. Examples of such fasteners
include a hinge, locking screw, latch, sliding mechanism, and the
like. The interior chamber 21 may be suitable to house or enclose
various components of the heating device 1, such as the control
unit 27, the power supply 24 (FIG. 3), control and ignition
circuitry, electrical wiring, air and fuel hoses, and the like.
Each of such components can be serviced, replaced or accessed
through the support aperture 30 in the support 5. In one
embodiment, the support 5 may protect a valve and thermocouple
assembly 76 from damage, in the embodiments where the valve and
thermocouple assembly 76 (FIG. 5) is necessary. The valve and
thermocouple assembly 76 may be necessary in embodiments wherein a
gas supply is used to at least partially provide power to the
heating device 1.
[0036] With continued reference now to FIGS. 1-5, in one
embodiment, adjacent to the air intake end 19 of the heating device
1 and positioned between the intake guard 14 and the inner cylinder
assembly 33, the motor 15 may be supported by means of a bracket 32
that extends between the lower and upper housing portions 7, 8 of
the outer cylinder 11. The motor 15 may comprise an AC or DC motor
utilized to cause the rotation of fan blades 18. In one embodiment,
the motor 15 may comprise a DC motor that at least partially allows
the heating device 1 to achieve a reduced sound level during
operation of the heating device 1. The rotation of fan blades 18
may cause ambient air to be drawn through the intake guard 14 and
into the housing assembly 9. A portion of the air drawn into the
housing assembly 9 passes through the annular space 71 which
surrounds the inner cylinder 12. The passing of air through the
annular space 71 may provide cooling air which acts to at least
partially insulate the outer cylinder 11 from the inner cylinder
12. Another portion of the air drawn into the housing assembly 9
passes through holes or apertures formed in the inner cylinder
assembly 33 and into the combustion region 10. The air passing
through the inner cylinder assembly 33 may comprise a moving forced
air that is heated by the combustion of the air/fuel mixture as
described below and which exits the housing assembly 9 as heated
air through the discharge end 2 and passing through the baffle 13
thereby causing heated air to be circulated into the area desired
to be heated. In one embodiment, a drive shaft 16 may be
operatively connected between the motor 15 and fan blades 18. The
drive shaft 16 may extend from and may be rotationally driven by
the motor 15 and an end of the drive shaft 16 may be coupled to fan
blades 18. The operation of the motor 15 may cause the rotation of
the drive shaft 16 thereby resulting in the rotation of fan blades
18 which may cause ambient air to be drawn in the direction of
arrows 34 through the air intake end 19 as described above.
[0037] With continued reference to FIGS. 1-5, according to one
embodiment, the fuel assembly 17 may comprise a fuel tank 3 and a
supply assembly 36. The fuel tank 3 may be suitable for containing
a liquid fuel 20, as shown in FIG. 3, such as, for example, a
suitable grade fuel oil, kerosene, gasoline and the like. The
liquid fuel 20 may be utilized to supply a portion of the power
required for operation of the heating device 1. The fuel tank 3 can
optionally be formed as a singular molded unit or from two opposing
rectangular trays arranged with their openings facing each other.
For embodiments including a fuel tank 3 formed from two opposing
trays, the trays may be joined together by seam welding or
otherwise coupling flanges 3a extending around the perimeter of the
fuel tank 3. A removable filler cap 4 may cover a fueling aperture
(not shown) formed in a surface of the fuel tank 3 through which
the liquid fuel 20 may be added. In another embodiment, the fuel
tank 3 may comprise a tank or cylinder, not shown, suitable for
containing propane or similar fuels. In one embodiment, the housing
assembly 9 may allow for the mounting of the fuel tank 3 thereby
increasing the ease at which the fuel tank 3, including the fuel
contained therein, and the heating device 1 may be transported. In
another embodiment, the fuel tank 3 may comprise one or two
one-pound cylinders operatively connected to the heating device 1.
The cylinders may be moveable from a first use position into a
second position in which the cylinder can be replaced. This mode of
operation in one embodiment may be affected through the
incorporation of a braided gas hose which employs a sliding
mechanism in which the user physically pulls the cylinder from its
use position inside the housing assembly 9, to a replace position
outside of the housing assembly 9 via telescoping or sliding
movement of rails. In another embodiment, this mode of operation
may be effected by the fixed incorporation of the swivel body into
a door or adjustable panel 6 of the housing assembly 9 within which
is positioned the cylinder, thereby requiring the user to open the
door or adjustable panel 6 with cylinder attached for replacement
of the cylinder. In another embodiment, this mode of operation may
be effected by removal of the cylinder from within the interior
chamber 21 which is attached by a clamp and bracket within the
interior chamber 21 while in yet another embodiment, this mode of
operation may be effected by pivotal movement of a swivel body
within a pair of U-shaped clamps having a pivot rod interposed
therebetween. In yet another embodiment, this mode of operation may
be effected by a swivel weighted clip which requires tilting of the
heating device 1 prior to removal of the spent cylinder. The
cylinder may connect to a swivel body which connects to an
associated regulator (for decreasing the pressure of the exit port
gas) of the supply assembly 36.
[0038] With continued reference to FIGS. 1-5, according one
embodiment, the supply assembly 36 may comprise a burner assembly
23 and an ignition system 56. The burner assembly 23 may be adapted
to cause the liquid fuel 20 to be communicated from the fuel tank 3
wherein it can be subsequently atomized and combined with air or
other oxygen source in the combustion region 10, where it is then
combusted to generate the thermal energy for heating air being
forced through the heating device 1. In one embodiment, the burner
assembly 23 may allow the liquid fuel 20 to be pulled up or
communicated from the fuel tank 3 through a fuel conduit 39 and
into the burner assembly 23. The fuel conduit 39 may comprise a
connection valve 44 for operatively connecting the fuel conduit 39
and the fuel tank 3. In one embodiment, the connection valve 44 may
comprise an acme-type connection. The fuel conduit 39 may comprise
an integrated hose assembly, a separate hose assembly, or a
hose-less direct connect assembly. The fuel conduit 39 may comprise
any type of conduit suitable for communicating fuel from the fuel
tank 3 chosen with sound judgment by a person of ordinary skill in
the art. In another embodiment, the burner assembly 23 may be
adapted to allow fuel to be communicated from a tank or cylinder,
not shown, suitable for containing the liquid fuel 20, such as, for
example, a propane tank. The fuel conduit 39 may allow the fuel to
be supplied to a burner venturi 45 where it is mixed with ambient
air. The supply assembly 36 may comprise any type of supply
assembly designed to transmit an atomized air/fuel mixture into the
combustion region 10 chosen with sound judgment by a person of
ordinary skill in the art and is not intended to be a limitation of
the present invention.
[0039] With continued reference to FIGS. 1-5, a portion of the
burner assembly 23 may extend through an opening located centrally
in the inner cylinder assembly 33 to provide the un-ignited
air/fuel mixture at the end of the burner assembly 23 wherein the
un-ignited air/fuel mixture is urged towards the inner cylinder
assembly 33. The inner cylinder assembly 33 may be designed to
divert the air/fuel mixture radially into the combustion region 10
as the air/fuel mixture exits the burner assembly 23 wherein the
un-ignited air/fuel mixture may then be ignited and burned. In one
embodiment, the burner assembly 23 may comprise a design which
reduces the required air flow thereby reducing the power
requirements of the heating device 1. In one embodiment, the burner
assembly 23 may comprise a design that achieves a reduced sound
level resulting from the operation of the heating device 1.
[0040] With continued reference to FIGS. 1-5, initially, the
air/fuel mixture may be ignited by the ignition system 56. The
ignition system may be designed to ignite or cause the initial
combustion of the air/fuel mixture within the combustion region 10.
In one embodiment, the ignition system 56 may be operatively
connected to the control assembly 22 and may comprise one or more
components powered by the power supply 24.
[0041] With reference now to FIG. 6, in one embodiment, the control
assembly 22 may comprise the power supply 24, a control unit 27,
and a control panel 46. The power supply 24 may comprise the sole
or primary source of power for operation of the heating device 1 or
one or more components thereof. The power supply 24 may comprise
the sole or primary source of power for the heating device 1 for a
limited or an extended period of time. The power supply 24 may
enable the use of an external power source, described below, such
that the power supply 24 may be utilized as the primary source of
power or as a back-up source of power when the primary source, for
example, AC power supply, and/or gas supply, fails or is exhausted.
The power supply 24 can supply electric energy, at least
temporarily, to operate one or more electric components of the
heating device 1 while the heating device 1 is generating thermal
energy for heating its ambient environment.
[0042] With continued reference to FIG. 6, in one embodiment, the
power supply 24 may comprise a self-contained, on-board power
supply that comprises a power cord assembly 86 and/or one or more
portable energy sources 25 suitable for supplying electric energy,
at least temporarily, to operate at least a portion of the heating
device 1. The power cord assembly 86 may allow AC and/or DC power
from an external source, such as, for example, a conventional wall
outlet or a vehicle battery, to be used for a portion of the power
utilized for operating the heating device 1. The power supply 24
may allow the selective use of an external source and/or the
portable energy source 25 to be used as an alternative or
supplemental energy source providing at least a portion of the
operating or accessory power for the heating device 1. In other
embodiments, the power supply 24 may allow the portable energy
source 25 to be utilized simultaneously with a second power source,
such as, for example, gas or AC power source, wherein second power
source may supply power for the heating operations of the heating
device 1 and the portable energy source 25 may supply power to any
available peripheral devices of the heating device 1, such as, for
example, a fan function, light or fuel pump. Other simultaneous
uses enabled by the power supply 24 wherein the portable energy
source 25 can be utilized with a second power source (i.e., gas or
AC power supply) include embodiments wherein the power supply 24
enables the selective powering of at least one function of the
heating device 1 by the portable energy source 25 and enables the
second power supply to power at least one other function of the
heating device 1. Additionally, the power supply 24 may enable the
portable energy source 25 to power the heating device 1
consecutively or sporadically with the second power supply to
conserve the fuel, or prevent indoor air pollution.
[0043] With reference now to FIGS. 1-6, in one embodiment, the
portable power source 25 may be integrated into the housing
assembly 9 and/or within the interior chamber 21 of the heating
device 1. The portable power source 25 may be detachable from the
physical structure of the heating device 1 or may be positioned on
a physically separate structure from the heating device 1. In one
embodiment, the portable power source 25 may comprise a
rechargeable battery 25, such as, for example, a lithium ion
battery, which is integrated fully or partially with the housing
assembly 9. Examples of suitable portable energy sources include,
but are not limited to, a battery, thermoelectric generator, fuel
cell, ultra-capacitor, and any other type of portable energy source
chosen with sound judgment by a person of ordinary skill in the
art. An example of a suitable battery is the lithium secondary cell
battery (also called a lithium ion battery), a cutaway view of
which is shown schematically in FIG. 4. Details of such a battery
are disclosed in United States Patent Publication No. U.S.
2005/0233219, published on Oct. 20, 2005, which is incorporated in
its entirety herein by reference. Another example of a suitable
battery 24 is described in detail in United States Publication No.
U.S. 2005/0233220, published on Oct. 20, 2005, which is also
incorporated in its entirety herein by reference. This, or
batteries with similar performance characteristics may be utilized
to supply electric energy, at least temporarily, to one or more
electric components of the heating device 1.
[0044] The aforementioned lithium ion examples of a suitable
battery that can be used as the portable power source(s) of the
power supply 24 may include a high-capacity lithium-containing
positive electrode in electronic contact with a positive electrode
current collector. A high-capacity negative electrode is in
electronic contact with a negative electrode collector. The
positive and negative collectors are in electrical contact with
separate external circuits. A separator is positioned in ionic
contact between with the cathode (positive terminal) and the anode
(negative terminal), and an electrolyte is in ionic contact with
the positive and negative electrodes. The slow discharge rates of
the battery allow for extended shelf-life and extended use
characteristics.
[0045] The total and relative area specific impedances for the
positive and negative electrodes of such exemplary batteries are
such that the negative electrode potential is above the potential
of metallic lithium during charging at greater than or equal to 4 C
(4 times the rated capacity of the battery per hour). The current
capacity per unit area of the positive and negative electrodes each
are at least 3 mA-h/cm2 and the total area specific impedance for
the cell is less than about 20 .OMEGA.-cm2. The ratio of the area
specific impedances of the positive electrode to the negative
electrode is at least about ten.
[0046] Also, for the lithium ion batteries discussed in the
examples above, the area specific impedance of the total cell is
localized predominantly at the positive electrode. The charge
capacity per unit area of the positive and negative electrodes each
are preferably at least 0.75 mA-h/cm2, more preferably at least 1.0
mA-h/cm2, and most preferably at least 1.5 mA-h/cm2. The total area
specific impedance for the cell is less than about 16 .OMEGA.-cm2,
preferably less than about 14 .OMEGA.-cm2, and more preferably less
than about 12 .OMEGA.-cm2, more preferably less than about 10
.OMEGA.-cm2, and most preferably less than or equal to about 3
.OMEGA.-cm2. The negative electrode has an area specific impedance
of less than or equal to about 2.5 .OMEGA.-cm2, more preferably
less than or equal to about 2.0 .OMEGA.-cm2, and most preferably
less than or equal to about 1.5 .OMEGA.-cm2.
[0047] Examples of suitable materials for the positive electrode
include a lithium transition metal phosphate including one or more
of vanadium, chromium, manganese, iron, cobalt, and nickel.
Examples of suitable negative electrode materials include carbon,
such as graphitic carbon. The carbon is selected from the group
consisting of graphite, spheroidal graphite, mesocarbon microbeads
and carbon fibers.
[0048] Embodiments of the batteries discussed above can optionally
include a battery element having an elongated cathode and an
elongated anode, which are separated by two layers of an elongated
micro-porous separator which are tightly wound together and placed
in a battery can. An example of a typical spiral electrode
secondary cell is shown in FIG. 4, the details of which are
discussed in U.S. Patent Publication 2005/0233219 and U.S. Pat. No.
6,277,522, both of which are incorporated in their entirety herein
by reference. The secondary cell 200 includes a double layer of
anode material 220 coated onto both sides of an anode collector
240, a separator 260 and a double layer of cathode material 280
coated onto both sides of cathode collector 300 that have been
stacked in this order and wound to make a spiral form. The spirally
wound cell is inserted into a battery can 320 and insulating plates
340 are disposed at upper and lower surfaces of the spirally wound
cell. A cathode lead 360 from anode collector 300 provides
electrical contact with the cover. An anode lead 380 is connected
to the battery can 320. An electrolytic solution is also added to
the can.
[0049] With reference now to FIGS. 3 and 6, in one embodiment, the
heating device 1 may comprise one or more components utilizing DC
electric energy and can be equipped with a rectifier 58 that
converts alternating current ("AC") electric energy from an
external source conducted via a plug 28 of the power cord assembly
86 into DC electric energy. The rectifier 58 may be operatively
coupled to the power supply 24 and the control assembly 22 to
distribute DC electric energy as needed for proper operation of the
heating device 1. When AC electric energy from an external source
is unavailable or not being utilized, the rectifier 58 can conduct
DC electric energy from the power supply 24 via a conductive
pathway 64 to the control assembly 22. Since rectification of the
DC electric energy from the power supply 24 is not needed if DC
electric energy is demanded, the rectifier 58 can merely establish
the conductive pathway 64 leading to the control assembly 22. In
response to a control command input by the operator, the control
assembly 22 can selectively establish and break conductive pathways
corresponding to the control command to activate and deactivate the
appropriate electric component(s) of the heating device 1.
[0050] With continued reference to FIGS. 3 and 6, alternate
embodiments of the heating device 1 can optionally include a motor
15 or other electric component that is designed to be energized by
AC electric energy. For such embodiments, if the power supply 24
comprises a DC source of electric energy, the heating device 1 can
further include an inverter 66 to convert the DC electric energy
from the power supply 24 into AC electric energy to be utilized by
the motor 15 or other component requiring AC electric energy. When
an external source of AC electric energy such as a wall outlet or
generator is available, the rectifier 58 can conduct the AC
electric energy via a conductive pathway to the control assembly 22
without rectifying it into DC electric energy. Thus, the AC
electric energy conducted by the power cord assembly 86 from the
external source is conducted to the control assembly 22 or directly
to one or more components of the heating device 1 as AC electric
energy for use in energizing one or more AC electric components
corresponding to a control command input by the operator via switch
42, control panel 46, and the like. Additionally, if an external
source of AC electric energy is available, the rectifier 58 can
simultaneously rectify a portion of the AC electric energy into DC
electric energy for supplying both AC and DC electric energy to the
heating device 1. If the heating device 1 includes one or more
electric components to be energized with AC electric energy and
such electric energy is not available from an external source of AC
electric energy, the inverter 66 may convert DC electric energy
from the power supply 24 into AC electric energy. This inverted AC
electric energy may be conducted by a conductive pathway 68 to the
control assembly 22, which may establish one or more conductive
pathways to the component(s) to be energized with AC electric
energy corresponding to the control command input via switch 42,
control panel 46, and the like.
[0051] With continued reference to FIGS. 3 and 6, in one
embodiment, the portable power source 25 may comprise a
rechargeable battery 25 that can be selectively recharged utilizing
power supplied by an external power source via the power cord
assembly 86. The battery 25 may be selectively removable from the
heating device 1 or may be fixedly connected to the heating device
1, as the recharging process may require the battery 25 to be
removed from the heating device 1 in certain embodiments, while the
battery 25 may be recharged while fixedly connected to the heating
device 1 in other embodiments.
[0052] With continued reference to FIGS. 3 and 6, in one
embodiment, the portable power source 25 may be in electrical
communication with a recharging unit 29. The recharging unit 29 may
be in electrical communication with one or more components of the
heating device 1. The recharging unit 29 may in electrical
communication with the portable power source 25 such that the
recharging unit 29 can utilize energy supplied by the portable
power source 25 and/or an external source of electrical energy to
recharge the portable power source 25. The recharging unit 29 may
be physically integrated with, selectively detachable from, or
comprise a separate component of the heating device 1. The
recharging unit 29 may allow the recharging of the portable power
source 25 while the portable power source 25 is operatively coupled
to the heating device 1 and/or when the portable power source 25
and/or recharging unit 29 is selectively removed from the heating
device 1. In one embodiment, the portable power source 25 may
comprise a battery and the recharging unit 29 may act as a
generator, converting the thermal energy of a burning fuel into
electrical energy thereby allowing the heating device 1 to become
substantially self-recharging, and not require any external power
source to recharge the battery 25 therein. In one embodiment, the
recharging unit 29 may include a heat-conducting substrate composed
of diamond or any other high thermal conductivity material,
disposed in thermal contact with a high temperature region of the
heating device 1. During operation of the heating device 1 while
using the liquid fuel 20 of other fuel source, a portion of the
heat generated may flow from the high temperature region into the
heat-conducting substrate, from which the heat flows into an
electrical power generator. A thermoelectric material such as a
BiTe alloy-based film or other thermoelectric material may be
placed in thermal contact with the heat conducting substrate. A low
temperature region is located on the side of the thermoelectric
material opposite that of the high temperature region. The thermal
gradient generates electrical power that can be used to recharge
the portable power source 25, comprising, for example, a lithium
ion battery. In one embodiment, the recharging unit 29 may comprise
a thermoelectric generator that uses catalytic combustion heat of
fuel gas as a heat source for the generator, and has a construction
wherein a thermoelectric element or a planar electric generation
unit comprising thermoelectric elements has a construction held
between the thermal input part and the heat radiation part, having
fuel gas supply means and means for mixing fuel gas with air. The
thermoelectric generator also has a structure such that the
combustion heat can be directly supplied to the thermoelectric
element by burning the mixed gas of fuel with air in a catalyst
part arranged in the thermal input part, the thermal input part
having a heat conductive end plate and a catalyst part which are in
contact with the thermoelectric element, the face opposite to the
thermoelectric element of the heat conductive end plate having a
structure of convex and concave configuration with the catalyst
part within the convex and concave configuration surface. The
recharging unit 29 may function by any method well known in the art
chosen with sound judgment by a person of ordinary skill in the
art.
[0053] With reference now to FIGS. 1 and 6, in one embodiment, the
power supply 24 may comprise a first portable power source 25a and
a second portable power source 25b. The first portable power source
25a and/or second portable power source 25b may be integrated into
the housing assembly 9 and/or within the interior chamber 21 of the
heating device 1. The first portable power source 25a and/or second
portable power source 25b may be detachable from the physical
structure of the heating device 1 or may be positioned on a
physically separate structure from the heating device 1. In one
embodiment, the first portable power source 25a and/or second
portable power source 25b may comprise a rechargeable battery, such
as, for example, a lithium ion battery, that is integrated fully or
partially with the housing assembly 9. The battery 25a, 25b may be
selectively removable from the heating device 1 or may be fixedly
connected to the heating device 1, as the recharging process may
require the battery 25a, 25b to be removed from the heating device
1 in certain embodiments, while the battery 25a, 25b may be
recharged while fixedly connected to the heating device 1 in other
embodiments. The first portable power source 25a and/or second
portable power source 25b may be in electrical communication with
one or more components of the heating device 1 by a wire
connection, a surface contact connection, a clip connector, or
other methods of electrical connection well known within the
art.
[0054] With continued reference to FIGS. 1 and 6, in one
embodiment, the first and second portable power sources 25a, 25b
may each comprise a battery and may be available within the heating
device 1 for extended use of the battery as a power source. In one
embodiment, the power supply 24 may comprise multiple lithium ion
batteries that may be used as reciprocal recharging sources,
wherein the first battery 25a can provide power to the external
load of the heating device 1 while also providing power to recharge
the second battery 25b. When the first battery 25a is depleted to a
certain voltage level, an exchanger switch, not shown, may be
activated and to cause the second battery 25b to begin providing
power to the external load, while also directing a portion of power
from the second battery 25b to recharge the first battery 25a. The
exchanger switch, not shown, may allow the power to be provided to
the external load of the heating device 1 without interruption,
while also increasing the useful life of the batteries.
[0055] In one embodiment, the first portable power source 25a may
comprise a thermoelectric generator and the second portable power
source 25b may comprise a battery. The thermoelectric generator may
be positioned within the housing assembly 9. In one embodiment, the
thermoelectric generator may be at least partially positioned
within the combustion region 10 to allow the thermoelectric
generator to convert heat supplied by ignition of the air/fuel
mixture into electric energy as is well known in the art. The
thermoelectric generator may be in electrical communication with
the control assembly 22 to communicate the generated electrical
energy thereto.
[0056] In one embodiment, the first portable power source 25a may
comprise a DC generator and the second portable power source 25b
may comprise a battery. The DC generator may be positioned within
the housing assembly 9 and may utilize the liquid fuel 20 to
generate electrical energy as is well known in the art. The DC
generator may be in electrical communication with the control
assembly 22 to communicate the generated electrical energy
thereto.
[0057] In one embodiment, the first portable power source 25a may
comprise an AC generator and the second portable power source 25b
may comprise a battery. The AC generator may be positioned within
the housing assembly 9 and may utilize the liquid fuel 20 to
generate electrical energy as is well known in the art. The AC
generator may be in electrical communication with the control
assembly 22 to communicate the generated electrical energy
thereto.
[0058] With reference now to FIGS. 1-6, the control unit 27 may at
least partially control the operation of the heating device 1. The
control unit 27 may at least partially control the operation of the
heating device 1 according to inputs provided by the operator
and/or executable commands stored on computer-readable media
associated with the control unit 27. In one embodiment, the control
unit 27 may be located within the housing assembly 9 of the heating
device 1. In a more specific embodiment, the control unit 27 may be
located within the interior chamber 21 defined by the support 5 and
may be electrical communication with the control panel 46, the
motor 15 and/or the fuel assembly 17. Electric energy can be
supplied by the power supply 24 to the control unit 27 via an
electrical conductor 64 disposed within the internal chamber 21 of
the support 5. The control unit 27 may be operatively coupled to
the user interface devices provided to the heating device 1 such as
the control panel 46, any other user input device, or any
combination thereof to carry out control commands input by an
operator. The control unit 27 may include necessary electrical and
electronic hardware, software, or a combination thereof chosen with
sound engineering judgment to respond to commands input by an
operator via one or more user interface devices provided to the
heating device 1. In one embodiment, the control unit 27 may
comprise a controller 61, a power management module 63, a motor
control module 65, and an ambient temperature compensation module
68. The controller 61 may comprise a microprocessor or similar
device for at least partially controlling the operation of the
heating device 1 according to predetermined executable instructions
stored on a memory portion 62 in response to actions by the
operator and/or operating conditions or parameters of the heating
device 1.
[0059] The motor control module 65 may be designed to at least
partially control the operation of the motor 15. In one embodiment,
the motor control module 65 may be in electrical communication with
the power supply 24 and the motor 15 and may control the operation
of the motor 15 by controlling the supply of electrical energy to
the motor 15 thereby causing fan blades 18 to rotate at a speed
that is directly related to the amount of electrical power supplied
to the motor 15. For example, to increase the speed of rotation of
fan blades 18 the motor control module 65 may cause the amount of
electrical power supplied to the motor 15 to be increased.
Conversely, to decrease the speed of rotation of fan blades 18 the
motor control module 65 may cause the amount of electrical power
supplied to the motor 15 to be decreased. In one embodiment, the
motor control module 65 may control the operation of the motor 15
to vary the speed of rotation of fan blades 18, and therefore the
output of the heating device 1, based at least partially on a
determined value of fuel intake and/or heat output of the heating
device 1.
[0060] In another embodiment, the motor control module 65 may
control the operation of the motor 15 to vary the speed of rotation
of the fan blades 18, and therefore the output of the heating
device 1, based at least partially on a current component
temperature of one or more components of the heating device 1. The
control assembly 22 may determine the temperature of one or more
components of the heating device 1. In one embodiment, the control
assembly 22 may determine the temperature of a component of the
burner assembly 23 and/or the housing assembly 9. The control unit
27 may cause the current component temperature to be stored in the
memory portion 62. The motor control module 65 may compare the
current component temperature with a predetermined component
temperature and may cause the operation of the motor 15 to be
altered based on the comparison. The predetermined component
temperature may be stored in the memory portion 62 and may be
inputted by the operator or during the manufacture of the heating
device 1. In one embodiment, if the motor control module 65
determines that the current component temperature is greater than
the predetermined component temperature, the motor control module
65 may cause the operation of the heating device 1 to be
terminated. The motor control module 65 may cause the operation of
the heating device 1 to be terminated by preventing electrical
energy from being supplied to the motor 15 and/or by transmitting
an electrical signal to the control unit 27. Upon receipt of the
electrical signal, the control unit 27 may cause the operation of
the heating device to be terminated. Additionally, upon terminating
the operation of the heating device 1 based on the current
component temperature, the control assembly 22 may prevent the
operation of the heating device 1 until the current component
temperature is less then the predetermined component temperature
and/or for a predetermined period of time. In one embodiment, the
control assembly 22 may determine the current component temperature
periodically. Each current component temperature determined by the
control assembly 22 may be stored in the memory portion 62. The
motor control module 65 may cause the operation of the motor 15 to
be altered based on the current comparison of the current component
temperature and the predetermined component temperature as well as
the previous comparisons. In one embodiment, the motor control
module 65 may cause the operation of the motor 15 to be altered
based at least partially on determining the rate of change between
the current component temperature and the predetermined component
temperature over a certain or predetermined period.
[0061] The power management module 63 may at least partially
control the operation of the power supply 24 to control the supply
of power to one or more components of the heating device 1. The
ambient temperature compensation module 68 may control the
operation of the motor 15 to vary the speed of rotation of the fan
blades 18, and therefore the output of the heating device 1, based
at least partially on an ambient temperature relative to a
predetermined temperature. In one embodiment, the control assembly
22 may allow the operator to input a desired or predetermined
temperature of the ambient environment surrounding the heating
device 1. The control unit 27 may cause the predetermined
temperature to be stored in the memory portion 62. The control
assembly 22 may determine the current temperature of the ambient
environment which the control unit 27 causes to also be stored in
the memory portion 62. The ambient temperature compensation module
68 may compare the current temperature with the predetermined
temperature and may cause the operation of the motor 15 to be
altered based on the comparison. For example, the ambient
temperature compensation module 68 may determine that the current
temperature is less than the predetermined temperature and cause
the electrical power supplied to the motor 15 to be increased. In
one embodiment, the control assembly 22 may determine the current
temperature periodically. Each current temperature determined by
the control assembly 22 may be stored in the memory portion 62. The
ambient temperature compensation module 68 may cause the operation
of the motor 15 to be altered based on the current comparison of
the current temperature and the predetermined temperature as well
as the previous comparisons. In one embodiment, the ambient
temperature compensation module 68 may cause the operation of the
motor 15 to be altered based at least partially on determining the
rate of change between the current temperature and the
predetermined temperature over a certain or predetermined
period.
[0062] With reference now to FIGS. 5 and 12, in one embodiment, the
control panel 46 may comprise an output adjustment interface 70.
The output adjustment interface 70 may be in electrical
communication with the control assembly 22 and may allow for the
selective control of the output of the heating device 1. In one
embodiment, the output adjustment interface 70 may comprise an
interface assembly, such as, for example, a knob, or other type of
adjustment device that allows the operator to selectively control
the speed of the motor 15 to control the output of the heating
device 1. The adjustment or actuation of the output adjustment
interface 70 may cause the control unit 27 to adjust the speed of
the motor 15 by adjusting or controlling the amount of electrical
power supplied to the motor 15 by the power supply 24. In another
embodiment, the output adjustment interface 70 may comprise an
interface assembly or other type of adjustment device that allows
the operator to selectively control the burn rate of the heating
device 1. The adjustment or actuation of the output adjustment
interface 70 may cause the control unit 27 to adjust the burn rate
of the heating device 1 by adjusting or varying the supply of
liquid fuel 20 and/or ambient air into the burner assembly 23
and/or the combustion region 10.
[0063] In one embodiment, the power supply 24 may be in electrical
communication with the power management module 63 such that the
power management module 63 can control the configuration of one or
more portable power sources of the power supply 24. For example,
the power management control module 63 may allow for the
configuration of one or more portable power sources of the power
supply 24 to be placed in parallel and/or in series when providing
power to one or more components of the heating device 1. The power
management module 63 may be in electrical communication with a
power selector actuator 67 of the control panel 46 may allow the
operator to selectively control the configuration of one or more
power sources of the power supply 24 for operation of one or more
components of the heating device 1.
[0064] With reference now to FIGS. 1-6 and 12, the control panel 46
may be operatively coupled to the heating device 1 to allow the
operator to control heating of the ambient environment by the
heating device 1. The control panel 46 may be in electrical
communication with the control unit 27 to transmit electrical
signals that can be received by the control unit 27 in response to
inputs or commands of the operator (i.e., actuation of one or more
components of the control panel 46 by the operator for controlling
or adjusting the operation of the heating device 1), upon
determining one or more operating conditions of the heating device
1, and/or determining one or more environmental conditions. The
control panel 46, in the illustrative embodiments shown in FIGS. 1
and 2, may include a thermostat interface 48 and an ignition switch
52. In one embodiment, the thermostat interface 48 can be rotated
about a central axis to a desired temperature to which the operator
wishes to heat the ambient environment of the heating device 1. The
thermostat interface 48 can be infinitely adjusted between high and
low temperature limits, or can be rotated to one or more
predetermined temperature settings such as LOW, MEDIUM and HIGH.
The temperature selected with the thermostat interface 48 can
govern operation of the motor 15, ignition of an air/fuel mixture,
the supply of liquid fuel 20 to the combustion region 10, the ratio
of air to fuel provided to the combustion region 10, the ignition
53, or any combination thereof. As is known in the art, a
thermostat, not shown, may be operatively coupled to the thermostat
interface 48 to control activation, deactivation, and operation of
any of these components to maintain the temperature within the
ambient environment of the heating device 1 at approximately the
temperature selected with the thermostat interface 48. The
thermostat interface 48 may be electrical communication with the
control unit 27 and may transmit signals to the control unit 27
thereby allowing the control unit 27 to control the operation of
the heating device 1 based at least partially on the data received
from the thermostat, not shown. In one embodiment, the thermostat
interface 48 may be integrated with the control panel 46. In
another embodiment, the thermostat interface 48 may comprise a
separate component that is selectively detachable from the control
panel 46. The selective detachment of the thermostat interface 48
may allow the operator to remotely control the operation of the
heating device 1. In one embodiment, the thermostat interface 48
may be hard-wired to the control panel 46 wherein an electrical
conductor suitable for allowing for the transmission of electrical
signals is operatively connected to and extends between the
thermostat interface 48 and the control panel 46. In another
embodiment, the thermostat interface 48 may comprise a wireless
device wherein electrical signals, such as, for example, radio
frequency (RF) signals, can be transmitted wirelessly between the
thermostat interface 48 and the control panel 46.
[0065] The power management module 63 may comprise a device for at
least partially controlling the supply of power to the heating
device 1. The power management module 63 may be in electrical
communication with the power supply 24 and the control unit 27 to
selectively supply power to components of the heating device 1 from
one or more sources of electrical power. The power management
module 63 may be in electrical communication with the control panel
46. The control panel 46 may comprise a power selector interface 67
that allows the operator to selectively control the source of power
to the heating device 1. In one embodiment, the power management
module 63 may at least partially control the recharging of the
portable power source 25 via power supplied by, for example, an
external power source, and may allow for the recharging of the
portable power source 25 both during operation of the heating
device 1 and while the heating device 1 is not operating.
[0066] With reference now to FIGS. 6 and 12, in one embodiment, the
control panel 46 may comprise a power indicator 69 for providing
information to the operator relating to the power supplied by the
power supply 24. In one embodiment, the power indicator 69 may
comprise a device for displaying the level of charge of the
portable power source 25. For example, in embodiments wherein the
portable power source 25 comprises a battery, the power indicator
69 may indicate when the battery is fully charged and/or has a low
or depleted charge. In another embodiment, the power indicator 69
may comprise a device for displaying information relating to the
source of power being supplied to the heating device 1. For
example, the power indicator 69 may indicate that power is being
supplied via the portable power source 25 or by an external source
of supply via the power cord assembly 86.
[0067] With reference now to FIGS. 1-6, in one embodiment, the
control assembly 22 may comprise an ODS system 31 to sense levels
of carbon monoxide or other indoor air pollution in the local
vicinity of the heating device 1. The ODS system 31 may be in
electrical communication with the power control unit 63. The power
control unit 63 may cause the heating device 1 to be switched to
electric power upon the determining that pollution or monoxide
levels become unsafe, or as otherwise programmed. In one
embodiment, the power supply 24 may comprise first and second
portable power sources 25a, 25b. The second portable power source
25b may comprise a battery, and upon the determining that pollution
or monoxide levels become unsafe, or as otherwise programmed, the
power control unit 63 may cause the first portable power source 25a
to stop supplying power to the heating device 1 and may cause the
second portable power source 25b to start supplying power to the
heating device 1. The second portable power source 25b (i.e., the
battery) may be used as the sole source of power to the heating
device 1 for a limited or extended period of time, or the second
portable power source 25b may be utilized simultaneously,
consecutively, or sporadically with the first portable power source
25a (i.e., an electric generator).
[0068] With reference now to FIGS. 1-3 and 6, in one embodiment,
the heating device 1 may further include an optional electric
energy outlet 81 into which external electric accessories such as
radios, clocks, power tools and the like can be plugged. The outlet
81 may include one or more female receptacles 83 that can receive
conventional two-prong electric power cord plugs. Accordingly, each
receptacle 83 may include at least two apertures 85 into which the
prongs of the plug provided to the external electric accessory are
inserted to establish an electrical connection between the heating
device 1 and the external electric accessory. The outlet 81 can act
as a source of AC electric energy to energize the external electric
accessory when a conventional wall outlet or generator is not
available. The outlet 81 can also act as an extension of a
conventional wall outlet or generator when such an external source
of AC electric energy is available. When an external source of AC
electric energy is unavailable, the inverter 66 can convert DC
electric energy from the power supply 24 into AC electric energy
that can be supplied via the outlet 81. The AC electric energy
output by the inverter 66 can be in the form of a sinusoid having a
peak in the form of a with a peak voltage of about 170 volts and a
frequency of about 60 Hz, similar to the AC electric energy sourced
by a conventional wall outlet. However, it should be noted that the
AC electric energy output by the inverter 66 can deviate from a
perfect sinusoid, and in fact, can take on the shape of a square
wave, triangular waveform, and any other waveform shape suitable
for energizing an external electric accessory.
[0069] When an external source of AC electric energy is available
to the heating device 1, the rectifier 58 can conduct the AC
electric from the external source to the control unit 27. The
control unit 27 may be operatively connected to the one or more
electrical outlets 81 to establish a conductive path there between.
Thus, in addition to controlling the flow of any AC electric energy
required to energize one or more components of the heating device
1, the control unit 27 can also direct the AC electric energy to
the outlet 81. Even when the heating device 1 is not combusting the
air/fuel mixture to deliver thermal energy to the ambient
environment of the heating device 1, the outlet 81 can still be
utilized to provide power to an external electric accessory. This
is true regardless of whether the AC electric energy is converted
from DC electric energy from the power supply 24 or supplied from a
conventional wall outlet, generator or the like through the plug 28
of the heating device 1. Thus, the power supply 24 provided to the
heating device 1 can selectively supply electric energy, AC, DC, or
any combination thereof to one or more of the following electric
components of the heating device 1: an igniter such as a hot
surface igniter, spark igniter, and the like; a fan; a blower; one
or more AC electric outlets 81; one or more lights 38; a
thermostat; and any combination thereof. Further, the power supply
24 can supply this electric energy during operation of the heating
device 1 (i.e., simultaneously while combustion of the liquid fuel
20 is taking place) or while the heating device 1 is not currently
operating (i.e., in the absence of the combustion of the liquid
fuel 20). And the electric energy supplied by the power supply 24
can be supplied at least temporarily in the absence of an external
source of electric energy, simultaneously with the supply of
electric energy from an external source, or as a backup power
supply.
[0070] The embodiments utilizing the power supply 24 as the sole
source of power allow for ease in portability of the heating device
1, as the heating device 1 is not confined to a certain location
due to availability of a gas supply or AC power source. The
embodiments that do not utilize a gas supply for any portion of the
power necessary to operate the portable heater eliminate concerns
of indoor air pollution and carbon monoxide production by the
heater, and further extend the use of the heater by not limiting
operation to the availability of a gas supply. The embodiments that
do not utilize AC power for any portion of the power required for
operation of the heating device 1 allow for increased portability
of the heating device 1 as the position of the heating device 1 is
not limited by the length of the AC power cord or AC power supply,
and also allows for use of the heating device 1 during periods of
time when AC power is not availability due to outages or other
unavailability of AC power.
[0071] The heating device 1 may also utilize the power supply 24
for power in any combination of the above mentioned ways. When more
than one energy source is available, the control assembly 22 may
allow the operator to selectively provide power to the heating
device 1 from each of the available energy sources. This choice may
be provided to the operator by allowing them to push a button, flip
switch, or otherwise affirmatively choose the energy source for
use.
[0072] With reference now to FIGS. 6 and 13-15, according to one
embodiment, the heating device 1 may comprise an infrared heater
400. The infrared heater 400 may comprise a gas-fired, unvested
heating device suitable for use in confined spaces such as, for
example, recreational enclosures. The infrared heater 400 may
comprise a housing assembly 402, a fuel assembly 404, and the
control assembly 22. The housing assembly 402 may comprise a front
face 406 and a rear face 408. The housing assembly 402 may comprise
the base for supporting the infrared heater 400. In one embodiment,
the housing assembly 402 may comprise a pair of elongated legs 410
laterally disposed along the outboard edges of the rear face 408
and the front face 406 respectively. A handle 412 may be recessed
from and extend from the top of the infrared heater 400 at an angle
directed away (approximately 15.degree.) from the front face 406.
The front face 406 may comprise a stepped recess formed in an upper
front corner region for supporting at least a portion of the
control assembly 22. In one embodiment, the stepped recess may
support the thermostat interface 48 described above. A shield or
metal grid 414 may be attached to the front face 406 of the
infrared heater 400 to provide protection to the heater components
and prevent accidental contact with the hot portions of the front
face 406. The shield 414 may comprise elongated wire metal strips
and peripheral pieces that are received in openings 416 in the
housing to secure the shield 414 to the infrared heater 400. An
opening or air inlet 418 may be disposed on a lower portion of the
front face 406 of the infrared heater 400 for receiving and
filtering air drawn into the housing assembly 402. The air inlet
418 may be formed from a series of elongated slits 420 spaced
equidistance across the housing assembly 402 beneath the shield
414.
[0073] With reference now to FIGS. 12-19, the fuel assembly 404 may
comprise a fuel tanks 422, a burner assembly 424, and a radiant
surface 426. The fuel tanks 422 may be secured to and partially
enclosed by the housing assembly 402. The fuel tanks 422 may
comprise a removable canister or tank that can be replaced by a new
tank or removed, refilled, and re-installed in the housing assembly
402. In one embodiment, a conical dome 428 may protrude from the
side of the housing assembly 402 and partially encloses the fuel
tanks 422. The burner assembly 424 may comprise a burner venturi
430 enclosed within the housing assembly 402. The burner venturi
430 may operate to mix oxygen and liquid fuel 20 for combustion.
The burner venturi 430 may comprise a hollow generally cylindrical
body 432 and a tapered mouth 434 having a wider diameter than the
body 432. The burner venturi 430 may be disposed at an angle a
relative to the longitudinal axis of the infrared heater 400. The
mouth 434 of the burner venturi 430 may be positioned on
approximately the same axial plane as the air inlet 418. The
cylindrical body 432 may extend upwardly from the mouth 434. An
orifice 436 may be in fluid communication with the fuel tanks 422
and may be located directly beneath the mouth 434 of the burner
venturi 430. In one embodiment, the fuel tanks 422 may be connected
to a regulator which connects to a valve and orifice 436 that may
be selectively adjustable between open and closed positions.
[0074] With continued reference to FIGS. 12-19, the radiant surface
426 may comprise a generally planar surface and may be positioned
within the housing assembly 402 and disposed at an angle a relative
to the longitudinal axis of the infrared heater 400. A rear face of
the radiant surface 426 may be in communication with a cavity or
plenum chamber 438. The plenum chamber 438 may receive the air/fuel
mixture from the burner venturi 430 and may cause the air/fuel
mixture to be distributed over and through the rear face of the
radiant surface 426. Thus, in operation, the orifice 436, attached
to the fuel tanks 422, may be opened releasing the liquid fuel 20,
such as, for example, propane, into the mouth 434 of the burner
venturi 430. The regulator may be associated with the orifice 436
to reduce the delivery pressure of the liquid fuel 20 from the fuel
tanks 422. The stream of liquid fuel 20 exiting the orifice 436 may
create a vacuum effect drawing air from the air inlet 418 into the
mouth 434 of the burner venturi 430. The liquid fuel 20 and air may
be thoroughly mixed in the burner venturi 430 and plenum chamber
438 in order to achieve substantially complete combustion and
produce a clean burning infrared heating surface. The air/fuel
mixture may travel upward through the cylindrical body 432 of the
burner venturi 430 until reaching the plenum chamber 438. To
prevent the air/fuel mixture from immediately exiting the plenum
chamber 438, a baffle 440 may be provided to force the air/fuel
mixture downward into communication with the rear face of the
radiant surface 426.
[0075] With continued reference to FIGS. 12-19, the radiant surface
426 may comprise a burner tile or a multi-ply screens (not shown)
that define a plurality of small openings which permit combustion
of the air/fuel mixture as it passes there through. A container 441
may house a pilot 442 and an igniter 444 for initially sparking or
igniting the air/fuel mixture. In one embodiment, an igniter button
450 for activating the infrared heater 400 may be supported in a
second recess disposed on the upper back corner of the side of the
housing assembly 402. In addition to housing the pilot 442 and the
igniter 444, the container 441 may house an oxygen depletion
system. The oxygen depletion system (ODS) may provide an automatic
shutoff mechanism when decreased oxygen levels and resulting
increased carbon monoxide concentrations are detected. In one
embodiment, a thermocouple may monitor changes in temperature of
the pilot flame which indicates changes in oxygen and carbon
monoxide levels. A reflector 446 may extend outwardly from the top
of the burner plenum 438 at an angle directed toward the top
portion of the front face 406 of the housing assembly 402. The
natural convective upward path of the combustion products leads the
combustion products into contact with the reflector 446. The
reflector 446, in addition to directing the radiant energy output
from the infrared heater 400 toward the front face 406 of the
housing assembly 402, may also act as a deflector and may reduce
the temperature of the combustion products exiting the infrared
heater 400. A first outlet 448 may be disposed near the top of the
housing assembly 402 allowing warm air to mix with combustion
products and exit the infrared heater 400 after contacting the
reflector 446. A second outlet 452 may be disposed rearward of the
first outlet 448 and may communicate with the interior of the
housing assembly 402. The second outlet 452 may provide a
continuous flow path for air (that does not enter the burner
venturi 430) to flow from the air inlet 418 around the rear of the
plenum chamber 438 and exit the housing assembly 402 rearward of
the reflector 446. A portion of the ambient air drawn into the
housing assembly 402 may be used for combustion purposes and the
remainder may convect upwardly along the rear of the plenum chamber
438 to exit via the second outlet 452. As the burner venturi 430 is
heated, the thermal convection properties urge the air/fuel mixture
through the upwardly angled burner venturi 430 creating a chimney
type effect. The chimney effect created increases the fresh air
flow velocity into the burner venturi 430, enabling the pressure
from the fuel tanks 422 to be reduced, yet burn efficiently on high
or low settings.
[0076] With reference to FIGS. 6 and 17-19, according to one
embodiment, the housing assembly 402 may comprise a motorized fan
454, such as, for example, a paddle or cage fan, positioned within
the housing assembly 402. The motorized fan 454 may at least
partially cause an improved air flow through the infrared heater
400. The motorized fan 454 may be in electrical communication with
the control assembly 22 such that the motorized fan 454 can be
supplied power by the power supply 24 as described above. The
motorized fan 454 may comprise a plurality of paddles or inwardly
extending panels for creating air movement through rotational
pivotal movement about axis 456. In one embodiment, the motorized
fan 454 may comprise a lower voltage fan, e.g., 3.0 volts, and may
be powered by a direct current motor. The motorized fan 454 may
provide an increased air flow that at least partially ensures
maximal cooling capacity on various metal and plastic components of
the infrared heater 400.
[0077] A light 38 can optionally be coupled to the heating device 1
to illuminate an environment within the vicinity of the heating
device 1. The light 38 can be any conventional electric light
including, but not limited to a fluorescent light, incandescent
light, high-intensity light emitting diode ("LED") array, and the
like. A clear or slightly opaque protective shroud or lens can
optionally be provided to protect the light 38 from being damaged
by other objects near the heating device 1. Further, operation of
the light 38 can be controlled by the operator with a switch 42
independent of the operation of the other components of the heating
device 1 and the combustion of fuel from the fuel tank 3. The
switch 42 can be any type of operator input device, such as a
multi-position switch, one or more push button switches (as shown
in FIGS. 1 and 2), and the like. In FIGS. 1 and 2, the switch 42
includes an ON pushbutton switch 42a and an OFF pushbutton switch
42b, which turn the light 38 on and off, respectively. According to
alternate embodiments, the switch 42 can optionally offer a
plurality of intensity settings, such as low, medium and high, or
can be controlled with an infinitely adjustable dimmer switch to
control the intensity of the light 42.
[0078] An alternate embodiment of a forced-air heater 110 according
to one embodiment is shown in FIG. 8. The embodiment in FIG. 8, in
combination with one or more of the features discussed above, can
optionally further include a chassis that facilitates mobility of
the heater 110, and the ability to be stored in a
substantially-vertical orientation with only minimal, if any,
leakage of the liquid fuel from the fuel tank 114. One or more
wheels 124 can optionally be provided to facilitate transportation
of the forced-air heater 110. Each wheel 124 can include a rim 126
provided with a rubberized exterior coating 128 about its exterior
periphery. According to an embodiment of the forced-air heater 110,
the fuel tank 114 includes a generally-cylindrical passage formed
in the housing through which an axle extends to support the wheels
124. Each wheel 124 can also optionally be positioned within a
wheel well 130 formed in the fuel tank 114. The wheel wells 130
allow the wheels 124 to be recessed inwardly toward the center of a
fuel tank 114 thereby giving the forced-air 110 a
generally-streamlined configuration.
[0079] A frame 132 fabricated from an arrangement of tubes or rods
made from a metal or other suitably-strong material for supporting
the weight of a fully fueled forced-air heater 110 forms a cage
that at least partially encases the heating conduit 112 and fuel
tank 114. The frame 132 includes a proximate end 134 and a distal
end 136 separated by longitudinally extending members 138. A cross
member 140 can serve as a handle at the proximate end 134, allowing
the operator to grasp the forced-air heater 110 and maneuver it as
desired. A member 138' can extend longitudinally along each side of
the forced-air heater 110 adjacent to the fuel tank 114 and
externally of the wheels 124. In this arrangement, the member 138'
allows for simplified installation of the wheels 124 and the frame
132, and also protects the wheels 124 from impacting nearby objects
while the forced-air heater 110 is being maneuvered.
[0080] FIG. 9 illustrates transportation of the forced-air heater
110 in a somewhat vertical orientation according to an embodiment
of the present invention. The orientation of the forced-air heater
110 shown in FIG. 9 is but one of the possible orientations in
which the forced-air heater 110 can be oriented without leaking
significant amounts of liquid fuel from the fuel tank 114. This
orientation is an example of what is meant herein by references to
an orientation other than the orientation in which the forced-air
heater 110 is intended to be fired, which is the orientation shown
in FIG. 8.
[0081] FIG. 10 illustrates an embodiment of a forced-air heater 110
in a substantially-vertical storage orientation. When not in use,
the forced-air heater 110 can be stood on the distal end 136 of the
frame 132. The tubing made from a metal or other strong material
that forms the distal end 136 of the frame 132 is patterned to give
the distal end 136 a suitably-wide footprint that can maintain the
forced-air heater 110 in the substantially vertical orientation
shown in FIG. 8. The footprint of the distal end 136 can optionally
be large enough to maintain the substantially-vertical orientation
of the forced-air heater 110 even when minor forces are imparted on
the forced-air heater 110 above the distal end 136 with reference
to FIG. 10.
[0082] While the forced-air heater 110 is in the
substantially-vertical storage orientation, a rain shield 142 is
positioned to interfere with the entry of falling objects or other
debris into the heating conduit 112. The rain shield 142 can be a
planar sheet of metal or other rigid material that extends between
the cross member 140 that serves as the handle and a second cross
member 144. With the rain shield 142 positioned as shown in FIG.
10, it interferes with the entry of falling objects into the end of
the heating conduit 112 in which air is drawn from the ambient
environment.
[0083] The forced-air heater 110 has been described thus far and
illustrated in the drawings as optionally including a rain shield
142 adjacent to the ambient air intake end of the heating conduit
112. However, it is to be noted that the present invention is not
limited solely to such an arrangement. Instead, the present
invention also encompasses a forced-air heater 110 that can be
stored in a substantially-vertical orientation such that the
discharge end of the heating conduit 112 from which heated air is
forced is aimed upwardly, and the ambient air intake end is aimed
toward the ground. Of course, the fuel-management system of the
present invention described below will be adapted accordingly.
[0084] FIG. 11 is a cross-section view of an embodiment of a fuel
tank 114, which forms a portion of the combustion heater's
fuel-management system. The fuel tank 114 includes one or more
cavities 146 that alternately accommodates liquid fuel and an air
gap that is shifted when the forced-air heater 110 is transitioned
from its firing orientation (shown in FIG. 8) to its
substantially-vertical storage orientation (shown in FIG. 10), and
vice versa. A fuel outlet 154 is provided adjacent to the lowermost
portion of the fuel tank 114 while the forced-air heater 110 is in
its horizontal firing position. Positioning the fuel outlet 154 in
this manner allows approximately all of the fuel to be removed from
the fuel tank 14 during operation of the forced-air heater 110.
[0085] A hose 158 is connected between the fuel outlet 154 and a
nozzle 160 through which the fuel is metered into the combustion
chamber 120. The hose 158 can be fabricated from any material that
will resist damage and degradation from exposure to the particular
fuel used to fire the forced-air heater 110. Examples of the types
of fuels the hose 158 will transport include, but are not limited
to, kerosene, diesel fuel oil, and the like.
[0086] The hose 158 includes an arcuate portion 162, which is also
referred to herein as a return curve 162. The return curve 162 is
positioned on the forced-air heater 110 such that the return curve
162 is oriented similar to a "U" while the forced-air heater 110 is
in its substantially-vertical storage orientation, with both arms
aimed upwardly in a direction generally opposing the acceleration
of gravity.
[0087] The location of the fuel inlet 148 through which liquid fuel
can be inserted into the fuel tank 114 limits the amount of fuel
that can be placed in the fuel tank 114. With the forced-air heater
110 in its firing orientation, the lowest point of the fuel inlet
148 marks the upper fuel level limit 150. Thus, the air gap 152a is
disposed above the upper fuel level limit 50 and the liquid fuel in
the fuel tank 14. When the forced-air heater 110 is transitioned to
the substantially-vertical storage orientation shown in FIG. 8, the
fuel in the fuel tank 114 shifts to position an air gap 152b
adjacent to the fuel outlet 154. An example of a suitable size for
the air gaps 152a, 152b is about 0.4 gallons with the fuel tank 114
at its maximum capacity, but air gaps 152a, 152b of any size is
within the scope of the present invention.
[0088] The shifting of the fuel in the fuel tank 14 when the
forced-air heater 110 is transitioned from the intended firing
orientation to the substantially-vertical storage orientation
creates a vacuum at the fuel outlet 154. The vacuum results in the
siphoning of fuel from the hose 158 back into the fuel tank 114
instead of allowing the fuel to leak from the nozzle 160.
Additionally, most, if not all of the remaining fuel not siphoned
back into the fuel tank 114 is allowed to pool in the return curve
162 in the hose 158 instead of draining from the nozzle 160. This
further minimizes leakage of the fuel from the forced-air heater
110.
[0089] Although much of the description above focuses on portable
forced-air heaters, fixed heating installations such as furnaces
are also within the scope of the present invention.
[0090] The embodiments have been described, hereinabove. It will be
apparent to those skilled in the art that the above methods and
apparatuses may incorporate changes and modifications without
departing from the general scope of this invention. It is intended
to include all such modifications and alterations in so far as they
come within the scope of the appended claims or the equivalents
thereof.
[0091] Having thus described the invention, it is now claimed:
* * * * *