Patent Application
20070272232
The presently preferred embodiment of the invention is illustrated in the figures.
The frame 32 is held in place by a top mounted hinge 54. The top mounted hinge 34 can take different forms, such as a pivot hinge or a continuous hinge, as is well known to those practiced in the art of making hinges. The continuous hinge shown in
Because the self closing screen 34 is hinged at the top it will default to the closed position. The self closing screen may also be latched in the closed position with the latch 36. The latch 36 can take different forms, such as a cam latch, swinging bar latch, slide bolt latch, etc., as is well known to those practiced in the art of making latches. In the example shown in
During use, the logset 48 and the fuel cartridge 46, which are not part of this invention but are shown for illustrative purposes, sit on the perforated metal shelf 38, which is positioned above the bottom wall 12. As shown in
The vast majority of the light of the fire passes through the self closing screen 34. The self closing screen 34 may be a “two mesh” screen, meaning it has two strands of wire per lineal inch, resulting in openings that are almost 0.5″ square. The wire used for the self closing screen 9 may be relatively light, such as 0.028″ diameter wire, or heavier wire, such as 0.047″ diameter.
The transparency level of the self closing screen 34 is much higher than that of many other fireplace screens. According to the Universal Wire Company, of Morrisville, Pa., which makes fireplace screen, such screens are commonly made out of mesh with eight openings per lineal inch, using 0.028″ diameter wire. According to the charts published by Cleveland Wire Cloth, of Cleveland, Ohio, another manufacturer of fireplace screen, a mesh made out of 0.028″ diameter wire that has nine strands of wire per lineal inch (resulting in eight openings per lineal inch) has an open area of 55.95%. Using the same wire, mesh with eight strands per inch results in 60.02% open area, and mesh with only six strands per inch has 69.6% open area.
Because the current invention is made to be used with a cartridge burner system that does not produce any sparks, and may use a 2 mesh self closing screen 34 made with 0.28″ wire, the percentage of open area on the self closing screen 34 is 89.11%, meaning over 89% of the light from the fire passes through. Even if the self closing screen 34 is made with heavier wire, such as 0.047″ diameter wire, its transparency level is still about 82%. Hence, this firebox 1 allows much more of the fire to be seen through the self closing screen 34 than many other fireboxes whose screens do not close automatically.
Ambient air used for combustion enters the firebox through the self closing screen 34 or the lower vents 16. A substantial portion of the heat produced by the fire 52 will initially be absorbed by the metal heat absorber plate 42. Heated air exits the firebox 1 through the self closing screen 34 and through the top vents 30.
As an alternative embodiment the self closing screen 9 may be replaced with tempered glass 34A, also top hinged, so that it too defaults to the closed position.
