Fireplace cap

A fireplace cap includes a pair of hinged doors supported by a rectangular framework of first and second side rails, a header section, and a damper section. The components forming the framework are formed with flanges positioned at the rear of the cap for reinforcing purposes and to act as heat exchangers, picking up heat from a fire within the fire box of the fireplace. This cap can be easily custom fit to fireplaces having fire boxes of various sizes by selecting appropriate components for the framework. A top piece mounted to the header section may serve as a cooking surface. The doors may include optional glass plates supported for easy removal by angle members mounted to the back side of the doors. A latching mechanism, including eccentrically mounted latching arms, holds the doors tightly closed when latched. The top piece and side rails define sealing material receiving pockets and include retainers for holding sealing material to seal the cap against the front of the fireplace. Adjustable damper controls, together with an external lever actuated control for the existing damper of the fireplace, are utilized to control the flow of combustion air into the fire box. A removable key or handle is provided for the latching mechanism so that it may be stored in a cool location or out of the reach of children for safety purposes.

BACKGROUND OF THE INVENTION 
The present invention relates to a front, or cap, for a fireplace. 
Fireplace fronts, or caps, have heretofore been known. One such device is 
produced by Mt. Vernon Fireplaces, Inc., and has a flat plate for covering 
a fireplace opening to which a pair of hinged doors are mounted. Glass 
panels are included in the doors to enable the user to view the fire 
within the fireplace after the device is installed. 
However, known fireplace caps have lacked various desirable features and 
advantages resulting in a need for an improved cap. 
SUMMARY OF THE INVENTION 
The present invention comprises a fireplace cap which is positioned outside 
of the fire box of a fireplace. The cap covers and seals the fireplace 
opening to prevent room air from entering the fireplace, except as 
controlled by the cap. The cap includes a pair of hinged doors mounted to 
a surrounding framework which includes first and second side rail members, 
an upper header section, and a lower damper section. These components are 
angular beams for reinforcing purposes and for enhancing the heat transfer 
characteristics of the cap. 
As a more specific feature of the invention, a door latching mechanism, 
including latching arms eccentrically mounted to an actuator, are provided 
for holding the doors closed and in a substantially airtight fit. 
As a further feature of the invention, this latching mechanism is 
adjustable to eliminate any play in the doors when closed to thereby 
enhance the sealing of the doors. 
As another feature of the invention, a stop is provided to limit the 
maximum extension of the latching arms. 
As still another feature of the invention, the framework components are 
formed, rather than welded of flat stock, to enhance their strength and 
facilitate manufacture of the cap. 
As a further feature of the invention, a top piece is mounted to the header 
section and includes a cooking surface. 
As still another feature of the invention, the side rail members and top 
piece are formed with flanges so as to define sealing material receiving 
pockets within which sealing material is retained by a retainer to enhance 
the sealing of the cap to the fireplace. 
As a still further feature of the invention, a removable key or handle is 
provided for operating the door latching mechanism; when removed, the key 
may be stored in a cool location, or out of the reach of children, for 
safety purposes. 
As another feature of the invention, the doors each include an optional 
window opening covered by heat-resistant transparent panels, the panels 
being mounted for easy removal from the fireplace doors for repairing 
sealing and cushioning strip surrounding the panel. 
As a further feature of the invention, the doors are also removable so that 
they may be packed separately from the front to facilitate shipping of the 
cap. 
As another feature of the invention, the cap includes an external lever 
actuated fireplace damper control for controlling the existing damper of 
the fireplace to thereby control the rate of combustion of fuel within the 
fireplace. 
As a still further feature of the invention, adjustable damper knobs on the 
front of the cap are provided for controlling the flow of initial 
combustion air into the fire box of the fireplace. 
It is an overall object of the invention to provide an approved fireplace 
cap. 
It is another object of the invention to provide a fireplace cap which is 
efficient in recovering heat from fuel burned within the fireplace and in 
controlling the combustion of fuel within the fire box. 
A further object of the invention is to provide a cap which may be easily 
custom manufactured to fit the varying dimensions of fireplace openings 
with a minimum inventory of parts required for such custom manufacture. 
A still further object of the invention is to provide a fireplace cap which 
is strong and durable. 
Another object of the invention is to provide a fireplace cap which is safe 
to use. 
Still another object of the invention is to provide a fireplace cap which 
is easy to install, clean, and which is virtually maintenance-free. 
A further object of the invention is to provide a fireplace cap which 
enhances the functioning of an existing fireplace. 
These and other objects, advantages, and features of the invention will 
become apparent with reference to the following description and drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
With reference to FIG. 1, a fireplace cap 10, in accordance with the 
invention, is positioned on a hearth 12 outside of the fire box of a 
conventional masonry, heatalator or other fireplace. Thus, the entire fire 
box is unobstructed by the cap and is available for use in burning fuel. 
As best seen in FIGS. 2 and 3, cap 10 includes a rectangular framework 
formed of four major components, including upright side rails 14, 16, a 
header section 20 interconnecting the upper ends of the side rails, and a 
damper section 22 interconnecting the lower ends of the side rails. These 
components define a fireplace cap opening through which access to the fire 
box is provided. An elongated top piece 24 overlies the header. The side 
rails 14, 16, header section 20, and damper section 22 are preferably of a 
strong, durable heat-conducting material, such as of a heavy gauge steel 
which is formed or bent into angular shape. In comparison to flat stock, 
this manner of manufacture reduces the amount of welding required because 
only four weld seams are needed to join these members. The elimination of 
welds adds extra strength to the cap. A pair of doors 26, 28 are hinged to 
the respective side rails 14, 16, for selective access to the interior of 
the fire box of the fireplace. 
More specifically, these components of the framework will next be described 
in greater detail. The side rails 14, 16 have an identical cross section 
as shown in FIG. 5. More specifically, side rail 16 includes a first 
upright flange portion 30. This flange 30 is laterally spaced from the 
fireplace opening and extends outwardly away from the masonry 32 of the 
fireplace, with an upright edge of the flange abutting the masonry when 
the cap is installed. The side rail 16 bends through a ninety-degree angle 
from flange 30 to form a first step 34. This step 34 parallels the masonry 
and, together with flange 30, forms a sealing material receiving pocket in 
which heat-resistant fiber or other material 62 is positioned to seal the 
gap between the side rail and fireplace. Retainers, such as plural wires 
64, spot-welded or otherwise mounted to the back side and along the length 
of step 34, impale the sealing material and hold it in place. From step 
34, the side rail turns outwardly through a ninety-degree angle to a riser 
portion 36 of a width or depth D. The riser portion parallels the first 
flange 30. From riser portion 36, the rail bends inwardly through an 
additional ninety-degree angle to form a second step 38 having a width W. 
This second step covers a portion of the fireplace opening. Finally, the 
side rail bends through still another ninety-degree angle and terminates 
in a reinforcing flange or rib 40 which extends toward the fireplace. This 
flange bounds the side margins of the cap opening. 
The header section 20 comprises a channel with respective upper and lower 
horizontal header section legs 42, 44, a vertical reinforcing flange 45 
projecting upwardly from header section leg 44, and a vertical header 
section face 46. In addition, the damper section 22 is also generally 
channel-shaped with an upper horizontal damper section leg 48, a vertical 
reinforcing flange 49 projecting downwardly from damper section leg 48, a 
vertical damper section face 50, and a lower horizontal damper section leg 
52. Leg 52 may be of one piece or comprise a flange of the same width as 
damper section leg 48, to which a filler plate is welded. The lower damper 
section leg 52 is relatively wide to provide a broad base for supporting 
the cap. Sealing material (not shown) may be placed under leg 52 for 
sealing purposes. Header section leg 44 bounds the upper margin of the cap 
opening while damper section leg 48 bounds the lower margin of the cap 
opening. Therefore, a continuous rib including the side rail flanges 40 
and legs 44, 48 surrounds and reinforces the cap opening. Reinforcing is 
also provided by the flanges 45, 49. 
In addition, the top piece 24 is of right-angular construction, with a 
horizontal cooking shelf portion 54 and a vertical back portion 56. A 
down-turned flange 58 is provided along the front edge of the shelf 54 
while a rearward extending flange 60 is positioned along the upper edge of 
the back section 56. Flange 60 abuts the fireplace masonry above the 
fireplace opening. As best seen in FIG. 4, back section 56 and flange 60 
define a sealing material receiving pocket within which sealing material 
62 is retained to seal the top of the cap. 
With components shaped as described above, the construction of the cap is 
more efficient, economical, and requires a minimum inventory of components 
to custom manufacture caps for fireplaces with various sized fireplace 
openings. That is, the doors 26, 28 are a standard size for all caps so 
that only one door size is required. In addition, side rails are 
inventoried with varying depths D and widths W, together with top pieces 
24, header sections 20, and damper sections 22 of appropriate lengths. 
Consequently, given the dimensions of a fireplace opening, the desired 
components may be readily selected and assembled to fit the customer's 
fireplace. 
The strength of the unit is enhanced, due to the rigid angular construction 
of the components. The heat transfer characteristics of the cap are also 
improved due to the light gauge metal utilized in the preferred 
embodiment. Also, the cap is more efficient in recovering heat from fuel 
burned in the fire box because of the various ribs and flanges which 
project from the back side of the cap toward the fire box. These ribs and 
flanges absorb heat from the fire, resulting in increased heat being 
radiated into the room from the burning fuel. Also, heat from the fire is 
stored in the mass of the fireplace masonry and radiated into the room 
containing the fireplace. 
A special latching mechanism 66 is provided to tightly seal and hold the 
doors 26, 28 closed. An identical mechanism is provided for each door and 
will be described for door 28, with reference to FIGS. 2 and 4. The 
latching mechanism 66 includes an actuator having a plate 68 pivoted by a 
pin 69 to the door 28. Respective upper and lower latching arms 70, 72 are 
eccentrically and pivotally mounted to the plate 68. The lower arm 70 
extends through a cylindrical guide 74 mounted to the back side of the 
door while the upper arm 72 extends through a similar guide 76. When the 
doors are latched as shown in FIG. 2, the arm 70 extends through an 
opening 80 in the damper section leg 48. At the same time, upper arm 72 
extends through an opening 82 in the header section leg 44. A stop 84 is 
mounted to the back of the header section face 46. This stop engages the 
arm 72 and limits the maximum extension of the latching arms to prevent 
over-centering and binding of the latching mechanism. 
The actuator also includes a front actuator portion 90 (FIGS. 1 and 4) 
mounted to pin 69 at the front side of the door 28. In the preferred 
embodiment, actuator portion 90 comprises a disc with a bore 92, across 
which a pin 94 extends. A removable key or handle 96, having a slot 98, is 
utilized to operate actuator portion 90 and the latching mechanism. That 
is, the handle 96 is positioned with the pin 92 in the slot 98 and then 
pivoted in one direction to retract the latching arms to permit the doors 
to open. The handle is pivoted in the opposite direction to extend the 
latching arms to hold the doors closed. When not in use, the handle is 
inserted within a cylindrical sleeve 100 mounted to side rail 16 where it 
will not get hot. In addition, the handle may be placed in a hard-to-reach 
location so that children cannot use the handle to open the doors when a 
fire is burning. 
With this door closure mechanism, the doors are tightly sealed when closed. 
The guides 74, 76 may be bent to eliminate any free play in the doors when 
latched. This adjustment feature helps insure a tight fit of the doors 
when closed. Also, a vertical lip is provided by a strip 102 mounted to 
the free edge of door 26. This lip bears against the door 28 when the 
doors are closed to seal the crack between the doors. 
In addition, optional window openings 106 may be provided in the respective 
doors 26, 28. A transparent heat-resistant panel or pane, such as ceramic 
glass, covers the openings 106 so that fire within the fire box may be 
viewed. As shown in FIG. 3, right angular members 110 are mounted to the 
inside of the doors along the respective sides and bottom of the window 
opening 106. The glass is then slid downwardly, in the direction of arrow 
112, into slots defined by these angled members, so that the panel is held 
in place. The panel can easily be removed by lifting it upwardly for 
repair purposes. In addition, a heat-resistant material, such as woven 
fiberglass 114, is adhesively secured to the four edges of the glass. This 
provides an airtight seal and cushion between the glass and door. 
A pair of damper openings 116 (FIG. 3) are provided through the damper face 
section 50 of the damper section 22. A threaded bolt 118 projects 
outwardly through these openings 116 from a bar welded to the inside of 
the damper face section. A damper control knob 122 is mounted to the bolt 
118. Control knob 122 is rotated to close the opening 116 completely, or 
to open it, as desired. 
For installation purposes, brackets 126 (see FIG. 2) are mounted to the 
framework of the cap. Eye bolts 128 are lagged into the masonry or steel 
at the inside of the fire box of the fireplace. Threaded rods 130 extend 
through the brackets 126 and eye bolts 128. Nuts on the rods 130 are then 
tightened to draw the cap snugly against the front of the fireplace. 
The apparatus also includes an external control for operating a 
conventional damper of the fireplace. With reference to FIGS. 1 and 2, 
this control comprises a rod with a first horizontal section 131 passing 
through side rail 16, positioned above the doors 26, 28, and pivotally 
mounted to the framework. The rod section 131 is bent where it emerges 
from the cap to form a lever section 132 which terminates in a socket 134. 
The socket 134 is adapted to receive the handle 96 for operating the lever 
to rotate the rod. A damper actuating arm 138 is slidably mounted to rod 
section 134 and projects outwardly therefrom. An elongated rod 140 (FIG. 
4) is utilized to couple the actuating arm 138 to the fireplace damper. 
When the lever section 132 is pivoted, rod section 131 and actuating arm 
138 pivot to open and close the damper. 
Typically, when a fire is first lit within the fireplace, the damper knobs 
122 are opened substantially to allow combustion air from the room to 
enter the fireplace. However, after the fire is burning, the knobs 122 are 
rotated to close off the damper openings. In addition, the fireplace 
damper is operated to close it almost entirely. Because of the tightness 
of the seal between the cap and the fireplace, little or no combustion air 
enters the fireplace from the room. Preliminary studies indicate that, 
under such conditions, combustion air, indicated by arrows 142, moves 
downwardly along the back side of the fireplace flue and into the fire 
box. Air currents established within the fire box sweep heated air within 
the fire box and toward the front of the cap, thereby enhancing its 
heating efficiency. 
Because the damper control is operable from the outside of the fire box, 
the fireplace damper may be shut in the event of a flue fire to help put 
it out. Also, fire within the fire box will go out, without smoke entering 
the room, because of the tight seal between the cap and front of the 
fireplace. 
Brackets 139 may be welded to one or both of the ribs 40 for supporting 
barbeque grills, pots, and the like within the fireplace. Thus, in 
conjunction with the cooking surface 54 of the top piece 24, the cap may 
function as a cook stove and barbeque, as desired. 
Having illustrated and described the principles of my invention with 
reference to one preferred embodiment, it should be apparent to those 
persons skilled in the art that such invention may be modified in 
arrangement and detail without departing from such principles. I claim as 
my invention all such modifications as come within the true spirit and 
scope of the following claims.