GAS HEATING APPLIANCE

CUISINIERE A GAZ

English Abstract

The present invention relates to a gas burner particularly suited for gas
heating applicances for cooking food. In particular the present invention
comprises a generally circular moulded body (100) including gases inlet (106)
and an internal cavity (114). The internal cavity (114) is covered by a
substantially transparent glass cap (108), which also bounds on the gas
outlets (116). In this fashion, due to the transparency of the glass cap (108)
at low flame improve controllability and safety are achieved by visual
feedback of the flame size.

French Abstract

La présente invention concerne un brûleur à gaz particulièrement adapté pour les cuisinières à gaz servant à la cuisson d'aliments. La présente invention concerne, en particulier, un corps moulé (100) généralement circulaire comprenant une entrée (106) de gaz et une cavité interne (114). La cavité interne (114) est recouverte d'un couvercle de verre (108) sensiblement transparent, se fixant également aux sorties (116) de gaz. La transparence du couvercle de verre (108) à faible flamme, permettant de voir la dimension de la flamme, augmente ainsi la capacité de réglage et la sécurité.

Claims

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CLAIMS
1. A gas burner comprising:
a body portion including a gas inlet and an open inner cavity in fluid
communication with said gas inlet,
a substantially transparent cover means adapted to engage or attach to said
body
portion and thereby substantially cover said inner cavity and,
a plurality of gas outlets substantially adjacent the boundary formed between
said
cover means and said body portion and in fluid communication with said inner
cavity,
wherein at least a portion of said gas outlets being visible through said
cover
means.
2. A gas burner as claimed in claim 1 wherein said cover means is
substantially
composed of glass.
3. A gas burner as claimed in claim 1 wherein said cover means is composed of
a
glass mixture with substantial resistance to thermal shock.
4. A gas burner as claimed in claim 1 wherein said cover means is composed of
glass
ceramic.
5. A gas burner as claimed in claim 1 wherein said cover means is composed of
a
silica based glass mixture.
6. A gas burner as claimed in claim 1 wherein said cover means in composed of
a
borosilicate glass mixture.
7. A gas burner as claimed in any one of the preceeding claims wherein said
plurality
of gas outlets comprises a number of channels formed in what is in use the
upper face of
said body portion, said channels running from the inner cavity of said body
portion to the

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outer circumference of said body portion.
8. A gas burner as claimed in any one of claims 1 to 6 wherein said plurality
of gas
outlets comprises a number of channels formed in what is in use the lower face
of said
cover means, said channels running from (when said cover means is in place
atop said
body portion) the inner cavity of said body portion to the outer circumference
of said
body portion.
9. A gas burner as claimed in any one of claims 1 to 6 wherein said plurality
of gas
outlets comprise a plurality of holes in said body portion, extending .from
said inner cavity
to the exterior.
10. A gas burner as claimed in any one of the proceeding claims wherein said
cover
means includes lettering or designs moulded into or printed onto what is in
use the
underside of said cover means.
11. A gas burner as claimed in any one of the proceeding claims wherein said
body
portion includes a centre portion and said inner cavity comprising an annular
cavity
around said centre portion, said plurality of gas outlets comprising inner
outlets facing
inwardly substantially toward the centre of said burner and outer outlets
facing
substantially outwardly of said burner, and said cover means comprising a
substantially
transparent annular ring substantially covering said annular cavity.
12. A gas burner as claimed in any one of the proceeding claims wherein said
cover
means including a tapered portion on the outer circumference thereof.
13. A gas burner substantially as herein described with reference to and as
illustrated
by the accompanying figures.

Description

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GA,.S HEATING APPLIANCE
TECHNICAL FIELD
This invention relates to a substantially transparent cap for a heating
appliance
particularly though not solely for use as a gas burner cooktop.
BACKGROUND ART
There are a number of methods known in the art for providing heating in a cook
top. One of the preferred methods is using a gas burner due to the ability to
deliver high
levels of heating when required and also relatively fine levels of control. It
is typical of
such gas burners that the finest levels of control will be desired at the low
end of the
output range.
Various methods have been postulated in order to implement fine control in the
lower output range. For example, US 5,009,393 discloses a gas turn down valve
with a
relatively gradual control characteristic which provides a greater level of
control
especially at lower outputs compared to traditional gas valves. In a further
improvement
described in Korean Patent 9,208,198 an electromechanical actuator is used to
rotate the
gas valve in order to achieve fine levels of control across the entire range
of output.
However, while these prior art systems do provide improved control, it would
be
desirable to have a simple system which by way of visual feedback allowed fine
control
at low levels of burner output.
DISCLOSURE OF THE INVENTION
It is an object of the present invention to provide a gas burner which goes
someway
to achieving the above mentioned desiderata or which will at least give the
public a useful
choice.
Accordingly in a first aspect the present invention consists in gas burner
comprising:
a body portion including a gas inlet and an open inner cavity in fluid
communication with said gas inlet,
a substantially transparent cover means adapted to engage or attach to said
body
portion and thereby substantially cover said inner cavity and,
a plurality of gas outlets substantially adjacent the boundary formed between
said

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cover means and said body portion and in fluid communication with said inner
cavity.
To those skilled in the art to which the invention relates, many changes in
construction and widely differing embodiments and applications of the
invention will
suggest themselves without departing from the scope of the invention as
defined in the
appended claims. The disclosures and the descriptions herein are purely
illustrative and
are not intended to be in any sense limiting.
BRIEF DESCRIPTION OF THE DRAWINGS
One preferred form of the present invention will now be described with
reference
to the accompanying drawings in which;
Figure 1 is a cut-away view of the gas burner according to the preferred
embodiment of the present invention,
Figure 2 is a plan view of the body portion according to the preferred
embodiment
of the present invention,
Figure 3 is a perspective view of the substantially transparent glass burner
cap
according to the preferred embodiment of the present invention,
Figure 4 is a plan view of the gas burner at a low flame setting according to
the
preferred embodiment of the present invention,
Figure 5 is a plan view of the gas burner on a high flame setting according to
the
preferred embodiment of the present invention,
Figure 6 is a side view of the wok-style burner, and
Figure 7 is a plan view of the wok-style burner.
BEST MODE FOR CARRYING OUT THE INVENTION
Referring now to Figure 1 and 2 a gas burner is shown according to the
referred
embodiment of the present invention. The gas burner is formed of a body
portion 100
including a gas inlet 102 and an internal cavity 104 such that the gas flows
from the gas
supply 106 into the internal cavity 104. The top of the internal cavity 104 is
closed off
with a substantially transparent glass cap 108 which attaches overtop of and
overhangs the
body portion 100. The gas then flows from the internal cavity out through
outlet channels
112 formed on the top face 114 of the body portion 100 to the outlet ports 116
where the
gas is ignited and heats the cooking vessel (not shown).

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Referring to Figure 3 ~ a see the burner cap 108 in more detail. The cap 108
may
optionally include a central co a 1 SO designed to fit down the internal
cavity (104, Figure
1 ) of the body portion ( 100, Figure 1). On the underside is a flat annular
face 152
designed to sit firmly upon the upper face ( 114, Figure 1 ) of the body
portion. The cap 108
also includes an outer flange 156, which overhangs the body portion ( 100,
Figure 1 ). The
outer flange 156 is designed to diffuse the flames before they contact the
heating vessel.
The glass cap itself is composed of a typical ceramic type glass. Such glass
is
designed with a significant resistance to thermal shock and high contact
temperature, such
as expected when exposed to a gas fuelled flame. A Borosilicate based glass
would be
particularly appropriate.
The present invention is shown in use in Figures 4 to 5. At low flame, seen in
Figure 4 the actual flame 200 is only seen by virtue of the cap 202 being
transparent. At
high flame the flames 204 extent past the outer flange 206, and are evenly
distributed
around the circumference. By virtue of the flames being visible at low flame
more
accurate control and greater safety is possible over prior art burners.
A further improvement would be to mould designs or text onto the underside of
the
glass cap. This would allow the top face to be easily cleaned. The
manufacturers name
or other designs would then be visible from above.
It will be appreciated that by providing a low thermally conductive material
such
as the glass cap as opposed to the conventional cast iron, or highly thermally
conductive
caps, that the performance of the gas burner may improve. At low flame with a
highly
thermally conductive cap there is the potential for ''quelching" or partial
extinction of the
flame. This results in partial combustion with the by-product of higher CO
emissions.
With the low thermal conductivity of the glass cap according to the present
invention, the
potential for "quelching" is much reduced. Therefore the burning is more
controlled, more
efficient and the CO emissions are potentially reduced, especially at low
outputs.
Another advantage to the present invention relates to the fact that with glass
or
other transparent thermally retardant material as the burner cap, the need for
a separate
coating operation of the burner cap is eliminated. Traditionally with cast
iron or cast
aluminium burner caps, due to the fact that they are constantly in contact
with combusting

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illustrated in a configuration for a wok-style burner. In this case the main
body 210 is
substantially composed as described in the preceeding embodiments, having
outlets 212
on the outer periphery 214 of a raised portion 211 inset from the edge of the
main body
210. However rather than having the inner cavity completely open, the main
body
includes a covered centre section 216 extending approximately 2/3 the radius
of the outer
periphery 214 to form an inner periphery 218 to the raised portion. Included
on the inner
periphery are a further set of outlet ports 220 to provide flames towards the
centre of the
wok to provide more even heating and to ensure that the centre of the wok is
sufficiently
hot as is often desirable when cooking with a wok.
Also shown in Figures 6 and 7 is the trivet plate 222 which supports the wok
(not
shown) above the flames. The trivet 222 supports the wok about an annular path
224
which allow the wok (not shown) to be readily moved and removed, ensuring
adequate
flame contact to the underside of the wok and minimal flame contact on the
trivet.
The substantially transparent glass cap 226 as described in the previous
embodiments is in this case embodied in an annular ring with tapered portions
(or rounded
edges) at its inner 228 and outer 230 peripheries. Again the cap 226 is
composed of a
similar material and at low flame ensures full visibility of the flame. At
high flame as
shown in Figure 6, the flames can be seen both inwardly and outwardly of the
raised
portion 211. It will be readily apparent to one skilled in the art the
advantages to the
system described above and as defined in the appended claims.

Representative Drawing