Flame shielding device

A gas flame shield having a concave, spoon or shell-like shape and mounted to partially enclose the space surrounding the flame. Apertures are provided in the shield to prevent pressure reduction in the enclosed space and to provide an inlet for controlled entry of air to the flame.

BACKGROUND 
Gas burning appliances and other gas burning devices generally depend on a 
continuously burning pilot flame for igniting the main flame and for 
maintaining proper operation. If the pilot flame is extinguished, ignition 
will not take place and the appliance ceases to perform its function. Such 
accidental extinguishing or flame-out of the pilot flame is most often 
caused by wind gusts or drafts entering the pilot compartment and blowing 
out the pilot flame. This problem exists with a wide variety of appliances 
which employ gas-fired heat, including household appliances and devices as 
well as mobile equipment used for recreational purposes and outdoor gas 
burning devices. Flame-out of the pilot flame thus results in numerous 
service calls and other expenses and inconveniences and has been a 
persistent problem with gas burning devices. Small, solid wall flame 
shields have been used with commercial pilot assemblies, but generally 
have not eliminated the problem. 
SUMMARY OF THE INVENTION 
The present invention provides an improved flame shield adapted to be 
attached to standard pilot assemblies by conventional means. The shield is 
a spoon-or shell-shaped wall structure placed between the flame and the 
source of wind gusts or drafts. The shield has adequate concavity to 
partly enclose the space surrounding the pilot flame to deflect the gusts 
or drafts from the flame area, and contains a plurality of apertures 
located so as to permit entry of air to the flame area for proper 
combustion and to avoid pressure reduction in the shield cavity. The 
apertures may be placed with their longitudinal axes in various 
orientations with respect to one another so as to selectively distribute 
air flowing through the shield while substantially avoiding direct 
impingement upon the flame. 
The shield closely surrounds the burner nozzle and then extends outwardly 
away from and over the nozzle in a spoon-or shell-shaped configuration. 
This configuration results in a concave protected space for the pilot 
flame, with the shield enclosing the flame completely in the direction of 
the expected wind gusts or drafts (the "back") and at least partially 
enclosing the flame above and at the sides, leaving the flame open at the 
front. 
The apertures in the shield are preferably located in the area of the 
shield to the rear of and somewhat above the burner nozzle. Their size and 
number are sufficient to: (1) permit a flow of air through the shield into 
the flame area for proper combustion; (2) to avoid pressure reduction 
within the partially enclosed flame area; and (3) to prevent air burble 
around the shield and into the flame area. 
The apertures in the shield serve to control and limit the amount of air 
entering the flame area and preferably serve to direct the air flow so 
that it is diffused as it enters the protected flame area and does not 
impinge directly onto the flame. The apertures thus permit entry of 
sufficient air to sustain proper combustion and to provide sufficient 
pressure within the shield cavity to prevent gust air from burble around 
the edges of the shield, while the shield protects the flame from 
flame-out due to wind gusts or drafts by deflecting the main body of the 
moving air from the flame area. 
While the shield of this invention is specifically described in connection 
with a pilot flame, it may also be used for other flame shielding purposes 
such as for candles, alcohol lamps, camping equipment and similar fuel 
burning instruments.

DETAILED DESCRIPTION OF THE INVENTION 
As shown in FIG. 2, the shield 5 of this invention consists of a concave, 
spoon-or shell-shaped wall structure, preferably made of ceramic or other 
suitable flame resistant material. In its lower portion, shield 5 is 
shaped to fit closely around the burner nozzle 3, as shown more clearly in 
FIG. 3. Shield 5 then extends outwardly to form a concave wall preferably 
of such dimension as to partially enclose the space about flame 7 (shown 
e.g., in FIG. 3) above and on three sides of the flame. 
The size and shape of shield 5 will vary, depending on the size of the 
pilot assembly with which it is designed to be used. In the embodiment 
shown and described herein, shield 5 is approximately 2.5 inches high, 1.5 
inches wide at the widest portion, and 0.5 inches deep at the deepest 
portion. 
A plurality of apertures 6 extend through the upper-rear portion of shield 
5. Apertures 6 may be in sufficient number and suitably spaced and located 
to permit entry of enough air for proper combustion, to avoid reduced 
pressure within the cavity of shield 5, and to prevent air burble around 
the edges of shield 5 during wind gusts or drafts. In the particular 
embodiment shown and described herein, ten apertures the diameter of 
16-gauge wire located to the "back" of shield 5 and above nozzle 3 have 
been found to be effective for the practice of the invention with a shield 
of the dimensions specified above. Depending on the particular size of and 
application for shield 5, apertures 6 may be made to vary in size, 
location, and number. As shown in FIG. 1, apertures 6 may also be formed 
through the material of shield 5 with their longitudinal axes in various 
orientations with respect to one another so as to diffuse the flow of air 
away from direct impingement on flame 7 (shown in FIG. 3). The flow of air 
and orientation of apertures 6 are shown by the arrows in FIG. 2. It will 
be apparent, however, that the particular orientation of any one aperture 
is not critical, nor is it essential that the apertures 6 be in varying 
orientation, nor that the concave wall have such thickness as will provide 
for such varying orientation. 
As illustrated in FIG. 4, shield 5 is adapted to be mounted in a 
conventional manner, such as by glue or fasteners, to a conventional pilot 
assembly. The pilot assembly illustrated consists of a mounting bracket 1, 
a thermocouple 2, and a burner nozzle 3 into which gas is introduced 
through a gas line 4. As shown in FIGS. 1, 3, and 4, shield 5 is adapted 
to enclose the space about flame 7 at the "back" (i.e., the side of nozzle 
3 facing the source of wind gusts or drafts), to the sides, and above the 
flame in a canopy fashion, thus providing a protected area within the 
concavity of shield 5 in which flame 7 may burn. The preferred location of 
apertures 6 is best shown in FIG. 3. In the particular conventional pilot 
assembly shown, e.g., in FIG. 3, the upper portion of nozzle 3 is extended 
and shaped to form a solid flame-shaping wall. It is not essential that 
such a wall be present for successful operation of the shield of this 
invention. 
In operation, shield 5, containing apertures 6 serves to effectively shield 
flame 7 against flame-out from all but the most extreme wind gust 
situations. 
The foregoing detailed description has been given for clearness of 
understanding only, and no unnecessary limitations should be understood 
therefrom, as suitable modifications thereto for particular assemblies and 
uses within the scope of the invention will be obvious to those skilled in 
the art.