U.S. patent application number 10/655399 was filed with the patent office on 2005-03-10 for hot wire igniter.
This patent application is currently assigned to Channel Products, Inc.. Invention is credited to Horvath, David J., Schmiedlin, Mark D..
Application Number | 20050053884 10/655399 |
Document ID | / |
Family ID | 34226127 |
Filed Date | 2005-03-10 |
United States Patent
Application |
20050053884 |
Kind Code |
A1 |
Schmiedlin, Mark D. ; et
al. |
March 10, 2005 |
Hot wire igniter
Abstract
A hot wire igniter for igniting a gas appliance is disclosed.
The coil of the hot wire igniter is formed from a thin high
temperature, iron, chromium, aluminum alloy having a center section
that is tightly wound. Alternatively, the coil can be formed from
an alloy of platinum and iridium, or a similar high temperature
metal alloy. The coil turns initially do not touch one another and
each end of the coil is welded to a lead-in rod that is received
within an insulator member. The lead-in rods are connected to a
power source. The coil portion of the hot wire igniter is received
within a gas collector box which is attached to the burner to be
ignited. Application of the voltage source to the lead-in rods
causes the coil of wire to reach a temperature in excess of the
ignition temperature of the gas-air mixture which surrounds same
causing the ignition of the mixture.
Inventors: |
Schmiedlin, Mark D.;
(Columbia Station, OH) ; Horvath, David J.;
(Aurora, OH) |
Correspondence
Address: |
James A. Hudak, Esq.
Suite #304
29425 Chagrin Blvd.
Cleveland
OH
44122
US
|
Assignee: |
Channel Products, Inc.
|
Family ID: |
34226127 |
Appl. No.: |
10/655399 |
Filed: |
September 5, 2003 |
Current U.S.
Class: |
431/263 |
Current CPC
Class: |
F23Q 7/10 20130101 |
Class at
Publication: |
431/263 |
International
Class: |
F23Q 007/06 |
Claims
1) An igniter comprising an insulator member having at least two
spaced-apart bores therethrough, at least two electrodes formed
from solid metallic material, each of said electrodes being
received within one of said bores in said insulator member and
being positioned therein so that a portion thereof having a
substantially circular cross-section protrudes from an end of said
insulator member, and a single strand of substantially straight
high temperature wire formed into a coil and attached to the
exterior surface of the portions of said electrodes protruding from
said end of said insulator member.
2) The igniter as defined in claim 1 wherein said single strand of
substantially straight wire is formed from an iron, chromium,
aluminum alloy.
3) The igniter as defined in claim 1 wherein said single strand of
substantially straight wire is formed from an alloy of platinum and
iridium.
4) The igniter as defined in claim 1 wherein said coil of wire
includes at least two coil turns.
5) The igniter as defined in claim 4 wherein said coil turns are
initially in a spaced-apart relationship with respect to one
another.
6) The igniter as defined in claim 4 wherein through usage said
coil turns contact one another.
7) (Canceled).
8) The igniter as defined in claim 1 wherein the outer diameter of
said coil of wire approximates the diameter of each of said
electrodes.
9) (Canceled).
10) The igniter as defined in claim 1 wherein said portions of said
electrodes protruding from said other end of said insulator member
are swaged to accept in the attachment of a voltage source
thereto.
11) The igniter as defined in claim 1 further including a bracket
member having an aperture therein, said insulator member being
grippingly received within said aperture in said bracket
member.
12) The igniter as defined in claim 1 further including a gas
collector box, said coil of wire and said portions of said
electrodes protruding from said end of said insulator member with
said coil of wire attached thereto being received within said gas
collector box and being positioned therein so as to ignite the
gas-air mixture within said gas collector box.
13) The igniter as defined in claim 12 wherein said gas collector
box has an aperture therein for the receipt of the portion of the
said insulator member containing said portions of said electrodes
protruding from said end of said insulator member with said coil of
wire attached thereto.
14) The igniter as defined in claim 12 wherein said gas collector
box has an opening thereto permitting a gas-air mixture to be
received therein.
15) The igniter as defined in claim 12 wherein said gas collector
box further includes a mounting bracket attached thereto.
16) The igniter as defined in claim 15 wherein said mounting
bracket attached to said gas collector box is attachable to the
surface of a gas burner having outlet ports therein so as to
position said gas collector box adjacent said outlet ports in said
gas burner.
17) The igniter as defined in claim 1 further including a voltage
source to supply power to said igniter.
18) The igniter as defined in claim 17 wherein said voltage source
comprises at least one battery.
19) The igniter as defined in claim 17 wherein said voltage source
is a DC voltage source.
20) The igniter as defined in claim 17 wherein said voltage source
is an AC voltage source.
Description
TECHNICAL FIELD
[0001] The present invention relates, in general, to an igniter
and, more particularly, to a hot wire igniter that can be used for
the ignition of gas in any type of gas appliance.
BACKGROUND ART
[0002] Gas grills typically utilize propane gas, natural gas or
some type of manufactured gas as their fuel source and a spark
ignition system to ignite same. Such a spark ignition system can be
affected by environmental factors. For example, such a spark
ignition system may operate erratically in a very damp and/or windy
environment. Also, the operation of such a spark ignition system
can be adversely affected by organic contamination from the foods
being grilled. In addition, such a spark ignition system is noisy
when actuated since it typically utilizes a piezoelectric type
igniter that is mounted on a sheet metal panel which effectively
transmits the igniter actuation noise into the surrounding
atmosphere. Furthermore, the positioning of the electrical wiring
within the grill using a spark ignition system is critical since
the heat generated within the grill might adversely affect the
wiring. Also, due to the high frequency nature of the spark
produced by such ignition systems, the positioning of the wiring
within the grill can affect the efficiency of the resulting spark.
In addition, because such spark ignition systems produce high
voltages, any defects in the wiring or any deterioration thereof
can adversely affect the resulting spark. In view of these
disadvantages associated with spark ignition devices presently
utilized in gas grills, it has become desirable to develop another
type of ignition device, such as a hot wire igniter, for igniting
the grill.
[0003] A glow wire type ignition system is disclosed in U.S. Pat.
No. 4,130,104 (Kristen, et. al.), however, the application of the
igniter disclosed in this patent is for a gas stove, rather than a
gas grill. In this instance, the glow wire type igniter is a
replaceable component within the burner assembly for the stove and
is comprised of an igniter wire filament that is located within the
flue and is positioned so as to be visible through a display
window. Electrical switching means are provided to maintain the
igniter wire in the glowing condition when the burner assembly is
operating and to continue to maintain the igniter wire in the
glowing condition whenever the burner surface has reached a
temperature that exceeds a pre-determined level. In this manner,
the igniter wire provides two functions, i.e., to ignite gas that
emanates from the burner and to provide an indication when the
burner surface exceeds a pre-determined temperature. This type of
glow wire type ignition system is not appropriate for a gas grill
when the only function of such an igniter is to ignite the gas
emanating from the burner within same.
[0004] A glow plug that concentrates its heat at the tip of the
protective sheath of the plug so that the tip of the plug is the
first part of the plug to reach ignition temperature is disclosed
in U.S. Pat. No. 5,251,589 (Duba, et. al.). In this case, the
heating element has a complex shape since it is comprised of a
helical shape portion having a plurality of constant diameter turns
connected to a portion having more closely spaced turns of
decreasing diameter. The outer end of the heating element is
provided with a plurality of constant diameter turns that are in
contact with each other. In addition to the structure of the
heating element being quite complex, the glow plug disclosed in
this patent is for an internal combustion engine, rather than a gas
grill.
[0005] An ignition and control system for a gas burner which
includes both a ceramic glow igniter and a hot-wire actuated switch
that are connected in series is disclosed in U.S. Pat. No.
3,776,684 (Wright). In this case, the ceramic glow igniter is
typically constructed of silicon carbide and is used in conjunction
with the hot-wire actuated switch. The application of the ignition
and control system in this patent is for a furnace, rather than for
a gas grill.
[0006] A hot surface ignition system that utilizes a silicon
carbide igniter is disclosed in U.S. Pat. No. 4,976,605 (Geary). In
this case, the application of the hot surface igniter is for a gas
furnace, rather than a gas grill. A gas burner control system that
utilizes a silicon nitride type igniter is disclosed in U.S. Pat.
No. 4,925,386 (Donnelly, et. al.). Here again, the application of
this silicon nitride type igniter is not for a gas grill.
[0007] In view of the foregoing, it has become desirable to develop
a hot wire igniter that can be utilized for the ignition of gas in
any type of gas appliance.
SUMMARY OF THE INVENTION
[0008] The present invention overcomes the problems associated with
utilizing a spark ignition device for igniting a gas appliance by
providing a hot wire igniter that operates at a significantly lower
voltage and higher current than presently available spark ignition
devices. In addition, the lower voltage does not include a high
frequency component. The coil of the hot wire igniter of the
present invention is formed from a thin high temperature, iron,
chromium, aluminum alloy having a center section that is tightly
wound. Alternatively, the coil of wire can be formed from
platiniridium, which is an alloy of platinum and iridium, or a
similar high temperature metal alloy. Each end of the coil is
welded to a lead-in rod that is enclosed within an insulator
member. The lead-in rods are typically connected to a DC voltage
source. Alternatively, an AC voltage source or a chopped DC or AC
voltage source can be utilized as the voltage source. Application
of the voltage source to the lead-in rods causes the coil of wire
to reach a temperature in excess of the ignition temperature of the
gas-air mixture which surrounds same causing the ignition of the
mixture. The use of a hot wire igniter, rather than a spark
ignition device, permits the igniter to be used in very damp or
windy environments. Thus, the hot wire igniter of the present
invention can be readily used within a gas grill that is stored
outdoors. In addition, the operation of the hot wire igniter of the
present invention is not adversely affected by organic
contamination from the foods that are grilled since the surface of
the hot wire igniter reaches a temperature that causes such
contamination to be readily burned off and any leakage current
resulting from organic contamination which would normally absorb a
high voltage spark and render it ineffective is insignificant.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a perspective view of the hot wire igniter of the
present invention.
[0010] FIG. 2 is a front elevational view of the hot wire igniter
of the present invention.
[0011] FIG. 3 is a right side elevational view of the hot wire
igniter of the present invention; the left side elevational view
being a mirror image of this Figure.
[0012] FIG. 4 is a top plan view of the hot wire igniter of the
present invention.
[0013] FIG. 5 is a bottom plan view of the hot wire igniter of the
present invention.
[0014] FIG. 6 is a front elevational view of the heating coil
utilized by the hot wire igniter of the present invention.
[0015] FIG. 7 is an end elevational view of the heating coil
utilized by the hot wire igniter of the present invention.
[0016] FIG. 8 is a perspective view of a typical gas collector box
containing the hot wire igniter of the present invention and
showing the attachment of the gas collector box to a typical burner
within a gas grill.
[0017] FIG. 9 is a perspective view of a typical gas collector box
and showing the attachment of the hot wire igniter of the present
invention thereto.
[0018] FIG. 10 is an enlarged top plan view of a typical burner and
a typical gas collector box having the coil portion of the hot wire
igniter of the present invention therein and showing the attachment
of the gas collector box to the top surface of the burner.
[0019] FIG. 11 is an enlarged front elevational view of a typical
burner and a typical gas collector box containing the coil portion
of the hot wire igniter of the present invention therein.
[0020] FIG. 12 is a cross-sectional view of the burner and the gas
collector box taken across section-indicating lines 12-12 in FIG.
11.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] Referring now to the Figures where the illustrations are for
the purpose of describing the preferred embodiment of the present
invention and are not intended to limit the invention described
herein, FIG. 1 is a perspective view of the hot wire igniter 10 of
the present invention. The hot wire igniter 10 is comprised of two
(2) lead-in rods 12, a coil 14 of wire whose opposite ends are each
attached to one of the ends of the rods 12, an insulator member 16
and a mounting bracket 18.
[0022] The rods 12 are typically circular in cross-section, formed
from stainless steel, or the like, and are received within
substantially parallel longitudinally extending bores (not shown)
provided within insulator member 16. The portions 20 of the rods 12
emanating from the end 22 of the insulator member 16 are usually
swaged providing flat surfaces for the attachment of electrical
terminals (not shown). In addition, the swaged portions 20 of rods
12 are usually bent outwardly with respect to one another
permitting the easy attachment of the aforementioned electrical
terminals. (Alternatively, the swaged portions 20 of the rods 12
can be eliminated and the electrical attachment thereto can be
internal within the insulator member 16). The electrical terminals
are connected to a power supply (not shown), such as a DC voltage
source. Alternatively, the power supply can be an AC voltage source
(not shown) or a chopped DC or AC voltage source (both not shown).
The portions 24 of rods 12 emanating from the opposite end 26 of
insulator member 16 are usually bent outwardly with respect to one
another in order to provide a gap between the ends 28 thereof, as
shown in FIG. 4. Each end 30 of coil 14 is welded to a rod 12
adjacent its end 28 and the coil 14 is positioned so as to be
recessed within the gap provided between the ends 28 of the rods
12. As shown in FIGS. 2 and 3, the mounting bracket 18 includes a
sleeve portion 32 which may have a compression member therein (not
shown) to grippingly engage the outer surface of the insulator
member 16. In addition, the mounting bracket 18 has an aperture 34
therein, as shown in FIGS. 1, 4 and 5, permitting the mounting of
the igniter 10 within a collector box which is typically used in a
gas grill that utilizes traditional spark ignition devices.
Alternatively, the igniter 10 can be mounted directly to the burner
within the grill or can be attached to the grill through a mounting
or attachment arrangement.
[0023] The coil 14 is formed from an iron, chromium, aluminum alloy
wire which can be subjected to temperatures up to about
2,500.degree. F. Alternatively, the coil 14 can be formed from
platiniridium, which is an alloy of platinum and iridium, or a
similar high temperature metal alloy. The wire is typically 32
gauge or 0.008 inches in diameter and the center section of the
coil is tightly wound, as shown in FIG. 6. Typically, the coil 14
includes about six full coil turns, however, a lesser number of
turns can be utilized. A minimum of two full coil turns is
typically required to obtain the heat concentration that is
provided by the adjacent coil turns. The coil turns typically have
an outer diameter of about 0.052 inches which approximates the
diameter of each rod 12. When formed, the coil turns usually do not
touch one another and the oppositely disposed ends 30 of the coil
14 are substantially straight and concentric with the longitudinal
axis of the coil turns but offset therefrom so as to be positioned
adjacent the outer radius of the coil turns. During the welding
process, the coil 14 is oriented such that the coil turns are
positioned substantially above the oppositely disposed ends 30 of
the coil 14 in order to provide support and protection for the coil
turns after the coil 14 has been welded adjacent to the ends 28 of
the rods 12. During the conditioning and prove-in phase of the
igniter 10, the coil 14 is heated by the application of a current
source thereto for a pre-determined period of time annealing the
coil 14 and causing a protective oxide coating to form on the
surface of the coil 14. Through usage, the coil turns may contact
one another. It should be noted that the protective oxide coating
that forms on the outer surface of the iron, chromium, aluminum
alloy wire utilized for coil 14 prevents electrical shorts if,
because of coil sag and/or deformation due to usage and/or
handling, adjacent coil turns touch one another during
operation.
[0024] Suspending the coil 14 of wire between the rods 12 adjacent
their ends 28 may cause the coil 14 to sag and/or deform through
usage. The geometry utilized for the coil 14 overcomes the problem
of sag and/or deformation. In the present invention, the outer
turns of the coil 14 heat the inner turns of same. The innermost
coil turns typically experience the hottest temperatures and are
the ones most likely to sag and/or deform when heated. Through
usage, the innermost turns of the coil 14 may sag and/or deform but
since these turns are of a relatively small radius, few in number,
and are supported by the outer coil turns, the amount of sag and/or
deformation is insignificant and, therefore, does not significantly
affect the operation of the igniter 10. Any deformation of the coil
turns that may occur allows the gas-air mixture to enter the gaps
between adjacent turns to assist in the ignition of the gas-air
mixture and compensates for any decrease in the operating
performance of the coil 14 due to any increase in the electrical
resistance of same through usage. It should be noted that the
oppositely disposed ends 30 of the coil 14 radiate and/or conduct a
substantial portion of the heat contained therein to the
surrounding air and to the ends 28 of the rods 12 to which they are
attached. By radiating and/or conducting such heat, the oppositely
disposed ends 30 of the coil 14 are at a lower operating
temperature than the coil turns, and thus, typically do not sag
and/or deform. Because the heat is concentrated in the innermost
coil turns, any coil sag and/or deformation is minimized and does
not adversely affect igniter performance.
[0025] Referring now to FIG. 9, a perspective view of a typical gas
collector box 40 showing the attachment of the hot wire igniter 10
of the present invention thereto is illustrated. The gas collector
box 40 is comprised of a housing 42 and a mounting bracket 44
attached thereto. An aperture 46 is provided in the mounting
bracket 44. Gas collector box 40 has an opening, shown generally by
the numeral 48, thereto. The bottom surface 50 of gas collector box
40 has an aperture (not shown) therein. The hot wire igniter 10 of
the present invention is attached to the gas collector box 40 such
that the portion of the insulator member 16 adjacent the end 26
thereof is received within the aperture (not shown) in the bottom
surface 50 of gas collector box 40 and a fastener 52 is received
through aperture 34 in mounting bracket 18 to firmly attach
mounting bracket 18 to bottom surface 50 of gas collector box 40.
In this manner, the portions 24 of the rods 12 emanating from the
end 26 of insulator member 16 and the coil 14 attached thereto are
within the gas collector box 40 and adjacent the opening 48
thereto.
[0026] In order to mount the gas collector box 40 with the igniter
10 attached thereto to a typical burner, the mounting bracket 44 is
usually placed against the top surface 60 of the burner 62 in a gas
grill 64, as shown in FIG. 8. A fastener 66 is then received within
aperture 46 in mounting bracket 44 of gas collector box 40 to
attach the gas collector box 40 and the igniter 10 to the top
surface 60 of the burner 62, as shown in FIG. 10. In this manner,
the opening 48 to the gas collector box 40 is adjacent the outlet
ports 68 in the bottom portion of the burner 62, as shown in FIGS.
11 and 12. Gas emanating from ports 68 in burner 62 is received
through the opening 48 to the gas collector box 40 and mixes with
air therein permitting ignition of the gas-air mixture within the
gas collector box 40 by the coil 14 of the igniter 10. The result
is that the gas emanating from ports 68 in burner 62 is ignited
within several seconds after power is applied to the igniter 10. It
should be noted that the gas collector box 40 with the igniter 10
attached thereto can be mounted to the side surface or to the
bottom surface of the burner 62, rather than to the top surface 60
thereof. Alternatively, the igniter 10 can be utilized without a
gas collector box by mounting the igniter 10 directly to the burner
62 or to the body of the gas grill such that the coil portion
thereof is adjacent to the outlet ports of the burner.
[0027] The hot wire igniter 10 of the present invention offers a
number of advantages over presently available spark ignition
systems for gas grills. For example, the hot wire igniter 10
exhibits increased resistance to moisture, especially in those
situations where the grill is exposed to rain. In addition, any
degradation in the operation of the igniter 10 due to organic
contamination is not nearly as great as that which occurs for spark
ignition devices since the igniter 10 burns off any such
contaminants and any leakage current that results from organic
contamination and which would normally absorb the high voltage
spark, rendering it ineffective, is insignificant. The coil 14
within the igniter 10 is also resistant to mechanical shock and
vibration since it is formed from a metal alloy, rather than a
brittle ceramic-like material, and is protected because it is
recessed between the ends 28 of the rods 12. Furthermore, the
positioning of the wiring within the grill when utilizing the
igniter 10 is not as critical as the positioning of such wiring
when a spark ignition device is utilized since the igniter 10
utilizes a very low voltage which does not include a high frequency
component for operating purposes. Alternatively, an AC source or a
chopped DC or AC source of any voltage can be utilized. In
addition, operation of the igniter 10 is virtually silent when
compared with the operation of spark ignition devices that
typically utilize noisy piezoelectric elements to generate the
required spark energy. Also, the igniter 10 is less expensive to
produce than presently available electronic spark ignition devices
and is more reliable than such devices since it requires fewer
parts. Lastly, the portion of the igniter 10 that includes the coil
14 is readily receivable within a collector box used for a spark
ignition device permitting the easy replacement of such a spark
ignition device by the igniter 10.
[0028] Certain modifications and improvements will occur to those
skilled in the art upon reading the foregoing. It is understood
that all such modifications and improvements have been deleted
herein for the sake of conciseness and readability, but are
properly within the scope of the following claims.
* * * * *