U.S. patent number 3,905,351 [Application Number 05/539,443] was granted by the patent office on 1975-09-16 for fireplace heat distribution unit.
Invention is credited to Jeremiah J. Donovan, James M. Hatfield.
United States Patent |
3,905,351 |
Hatfield , et al. |
September 16, 1975 |
Fireplace heat distribution unit
Abstract
A fireplace heating unit includes an electric blower fed
distribution manifold adapted to extend across the front of a
fireplace chamber, a plurality of parallel, generally U-shaped heat
transfer conduits having their inlet ends connected in flow
communication with the rear of the manifold and outlet ends
arranged above the manifold to direct heated air into a room in
front of the fireplace, and an expanded metal grate supported by
and extending transversely of the heat transfer conduits.
Inventors: |
Hatfield; James M. (Eden,
NY), Donovan; Jeremiah J. (Lackawanna, NY) |
Family
ID: |
24151226 |
Appl.
No.: |
05/539,443 |
Filed: |
January 8, 1975 |
Current U.S.
Class: |
126/522;
D23/344 |
Current CPC
Class: |
F24B
1/1886 (20130101) |
Current International
Class: |
F24B
1/188 (20060101); F24B 1/00 (20060101); F24B
007/04 () |
Field of
Search: |
;126/121,163,164,165
;D7/207 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: O'Dea; William F.
Assistant Examiner: Capossel; Ronald C.
Attorney, Agent or Firm: Bean & Bean
Claims
I claim:
1. A fireplace heating unit adapted to be disposed in a fireplace
recess and comprising:
a horizontally elongated air distribution manifold;
a blower unit for supplying air to said manifold;
a plurality of generally U-shaped heat transfer conduits, said
conduits being essentially parallel and extending generally
rearwardly of said manifold in a right angular relationship
relative thereto, said conduits having lower leg portions, upper
leg portions and connecting portions, said lower and upper leg
portions of each conduit being essentially horizontal and arranged
in an essentially parallel, vertically spaced relationship with
their rearwardly disposed ends fixed in air flow communication by
their associated connecting portion, each of said lower leg
portions having a forwardly disposed end defining an air inlet
opening fixed in air flow communication with said manifold, each of
said upper leg portions having a forwardly disposed end defining an
air outlet opening arranged to overlie said manifold for directing
air forwardly thereof; and
a grate supported by said upper leg portions.
2. A fireplace heating unit according to claim 1, wherein said
grate is formed of expanded metal and has a generally rectangular
plan view configuration, said grate having a major rear portion
extending horizontally transversely of conduits and a minor
upwardly and forwardly inclined front portion arranged adjacent
said manifold.
3. A fireplace heating unit according to claim 1, wherein said
connecting portions define abutments engageable by rear marginal
edges of said grate for positionally orienting said grate relative
to said conduits.
4. A fireplace heating unit according to claim 1, wherein said
manifold is of essentially rectangular cross-sectional
configuration having vertically upstanding front and rear wall
portions, horizontally disposed upper and lower wall portions, and
vertically upstanding transversely extending end wall portions,
each of said lower leg portions having its forwardly disposed end
fixed to said rear wall portion of said manifold, each of said
upper leg portions having its forwardly disposed end supported by
said upper wall portion of said manifold, and said blower is
disposed in flow communication with said manifold through one of
said end wall portions.
5. A fireplace heating unit adapted to be supported on the floor of
a fireplace for use in circulating room air for heat exchange with
burning logs arranged in said fireplace, said unit comprising in
combination:
a horizontally elongated air distribution manifold having bounding
wall portions including in part upwardly, downwardly and rearwardly
facing wall portions, said downwardly facing wall portion being
adapted to rest on said floor for supporting said manifold;
a blower connected into said manifold through one of said bounding
wall portions for supplying air thereto;
a plurality of essentially parallel, generally U-shaped heat
transfer conduits extending generally rearwardly of said manifold
in a right angular relationship relative thereto, each of said
conduits having an elongated lower leg portion, an elongated upper
leg portion and a vertically upstanding connecting portion for
fixing rearwardly disposed ends of said lower leg portion and said
upper leg portion in air flow communication, each said lower leg
portion having a forwardly disposed end defining an air inlet
opening connected into said manifold through said rearwardly facing
wall portion at a point disposed vertically above said downwardly
facing wall portion, each said connecting portion being adapted to
rest on said floor and cooperate with said manifold to maintain its
associated lower leg portion essentially horizontal and in a
vertically spaced relationship relative to said floor, said
conduits being spaced relatively uniformly apart in a direction
horizontally lengthwise of said rearwardly facing wall portion,
each said upper leg portion extending horizontally forwardly from
its associated connecting portion and having a forwardly disposed
end thereof defining an air outlet opening and being supported by
said upwardly facing wall portion for directing air forwardly of
said manifold; and
a grate extending transversely of and supported by said upper leg
portion of each of said conduits.
6. A fireplace heating unit according to claim 5, wherein said
grate has a major rear log supporting portion dimensioned to be
flatwise supported on said upper leg portion of each of said
conduits and a minor front portion forwardly and upwardly inclined
relative to said major rear portion, and said connecting portion of
each of said conduits forms an abutment engageable by a rearwardly
disposed marginal edge of said major rear portion for orientating
said grate.
7. A fireplace heating unit according to claim 6, wherein said
grate is formed of a sheet of expanded metal having diamond shaped
openings extending therethrough.
Description
BACKGROUND OF THE INVENTION
Fireplace heating units of various types have been proposed for use
in increasing the space-heating efficiency of a fireplace over that
ordinarily obtained, as for instance those disclosed by U.S. Pat.
Nos. 2,359,197; 2,828,078; 3,001,521 and 3,240,206. Many of these
prior units are portable and feature a blower for supplying room
air to a tube or tubes, which are heated by burning logs and in
turn serve to heat air passing therethrough prior to its discharge
back into the room.
These prior units are believed to suffer from one or more drawbacks
including for instance expense of construction and
inefficiency.
SUMMARY OF THE INVENTION
The present invention is directed towards an improved fireplace
heating unit characterized as including a blower fed air
distributing manifold; a plurality of essentially parallel and
generally U-shaped heat transfer conduits arranged to extend
rearwardly from the manifold in a right angular relationship
relative thereto; and a grate supported on and extending
transversely of the conduits.
The U-shaped construction of the heat transfer conduits and the
mode of connecting same to the manifold provides for a relatively
low cost, but rugged construction. Further, this arrangement serves
to maximize the heating efficiency of the unit by providing an
extended flow path for air being heated, and when a removable grate
is employed permits periodic clearing of ashes from between the
conduits without requiring removal of the unit from within the
fireplace.
DRAWINGS
The nature and mode of operation of the present invention will now
be more fully described in the following detailed description taken
with the accompanying drawings wherein:
FIG. 1 is an exploded perspective view of the fireplace heating
unit of the present invention;
FIG. 2 is a top plan view thereof with grate removed;
FIG. 3 is a front elevational view thereof; and
FIG. 4 is a partially sectionalized view taken generally along line
4--4 in FIG. 2.
DETAILED DESCRIPTION
Reference is first made to FIG. 1, wherein the fireplace heating
unit of the present invention is generally designated as 10 and
shown as comprising a horizontally elongated air distribution
manifold 12; an electric or otherwise suitably powered blower 14; a
plurality of essentially parallel and generally U-shaped heat
transfer conduits 16; and a grate 18. As will be apparent from
viewing FIGS. 2, 3 and 4, unit 10 is adapted to be arranged in
supporting engagement with the floor 20 of a conventional fireplace
22, such that conduits 16 extend rearwardly into the fireplace
recess and manifold 12 extends transversely of the front of such
recess.
More specifically, manifold 12 is shown as having downwardly,
upwardly, rearwardly and forwardly facing side wall portions or
panels 24-27, respectively, and opposite end wall portions or
panels 28 and 29, which are suitably marginally edge joined to
define a plenum chamber 30, shown only in FIG. 4. The side and end
wall portions may be formed from individual sheets of a suitable
gauge metal stock material or may be formed by bending one or more
sheets into a desired form. The side wall portions are preferably
shaped and joined to define a manifold having a right angled
parallelogram cross-sectional configuration, such as a square, but
may of course be fabricated to produce a manifold of circular
cross-sectional configuration, if desired. Blower unit 14 is shown
in FIGS. 1-3 as including a blower section 32 having a forwardly
opening and suitably screened room air inlet 34 and an outlet duct
36 communicating with plenum chamber 30 through end wall 29; and a
heat insulated casing 38 for housing an electric motor, not shown.
The illustrated construction and mode of attaching blower unit 14
to manifold 12 is for reference purposes only; it being understood
that the blower unit may be of any suitable construction and
connected to the manifold in any desired manner.
Conduits 16 are preferably of identical construction, wherein each
includes an elongated lower leg portion 42, an elongated upper leg
portion 44 and an upstanding portion 46 for connecting rearwardly
disposed ends of leg portions 42 and 44 in flow communication. As
best shown in FIG. 4, lower leg portions 42 are arranged to extend
horizontally adjacent floor 20 and have their forwardly disposed
ends, which define air inlet openings 42a, fixed in flow
communication with manifold chamber 30 through rearwardly facing
wall portion 26 at a point, which is preferably disposed in a
spaced relationship to downwardly facing wall portion 24. Reference
is also made particularly to FIGS. 1, 2 and 4, wherein upper leg
portions 44 are shown as extending forwardly from connecting
portions 46 in an essentially vertically aligned and parallel
relationship with the lower leg portions and as having their
forwardly disposed ends, which define air outlet openings 44a,
disposed above upwardly facing wall portion 25 for the purpose of
directing heated air forwardly of manifold 12 for distribution in a
room. More uniform distribution of heated air may be achieved by
swivel connecting air director nozzles 48 to the forward ends of
one or more of upper leg portions 44, as indicated in FIGS. 1 and
2, and to prevent interference with rotatable adjustments of such
nozzles. The forward ends of the upper leg portions are preferably
disposed essentially flush with or slightly forwardly of side wall
portion 27.
Although each of conduits 16 may be of one piece construction, it
is preferable to separately form leg portions 42 and 44 from
lengths of iron or steel pipe having their rear ends threaded for
receipt within the ends of connecting portion 46, which is shown as
being conveniently formed from a pair of elbows, but may of course
be a single C-shaped fitting. This construction is desirable from
the standpoint of economy of materials and fabrication. Further, it
possesses the advantage that connecting portions 46 serve to define
abutments for properly positioning the rear marginal edge of grate
18 as best shown in FIG. 4, and cooperate with manifold 12 to
maintain lower leg portions 42 disposed in a slightly spaced
relationship relative to floor 20, whereby to provide a passageway
for combustion air between the lower leg portion and the floor as
well as between the upper and lower leg portions. The slight
spacing of the lower leg portions above the floor also affords
clearance for attaching lower leg portions 42 to rearwardly facing
wall portion 26 by the simple expedient of a pair of nuts 50, which
are threaded onto the lower leg portions and serve to clamp wall
portion 26 therebetween. Alternately, however, the lower leg
portions may be weld affixed to the manifold.
Also, it will be understood that in the preferred construction,
upwardly facing wall portion 25 is employed to support the
forwardly disposed ends of upper leg portions 44 and thereby
cooperates with the connecting portions 46 to maintain the upper
leg portions in a generally horizontally disposed relationship. As
a practical matter, initial assembly of the unit is facilitated by
providing a slight initial clearance between wall portion 25 and
upper leg portion 44, but when the unit is placed in use, the
weight of grate 18 and logs supported thereby and/or slight thermal
deformation of upper leg portion 44 and/or connecting portion 46
will normally effect lowering of the former into supporting
engagement with the manifold. While the close proximity or actual
engagement of upper leg members 44 with manifold wall portion 25
has been found effective to maintain the former in vertical
alignment with and essentially parallel to the lower leg portions,
the upper leg portions may, if desired, be spot welded to the
manifold, particularly when the unit is to be used under conditions
requiring periodic movement and/or rough handling.
Grate 18 is preferably of an expanded metal construction and of a
generally rectangular plan view configuration having a major or
expansive horizontally disposed rear portion 60 and a minor
forwardly and upwardly inclined front portion 62. For purposes of
illustration, the openings of grate 18 are shown as being diamond
shaped and being of relatively large size, as for instance 21/2
.times. 1 inch. While the configuration of the grate openings is
not critical, they should be of sufficient size to permit ash and
small embers to fall through the grate during use. As will be
apparent from viewing FIG. 4, rear portion 60 extends transversely
of conduits 16 and is arranged in supporting engagement with the
upwardly facing surface of upper leg portions 44, so as to arrange
front portion 62 above manifold 12 in a position where it serves to
constrain forward rolling movement or escape of the logs supported
by rear portion 60. Preferably, grate 18 is sized to rest in
supporting engagement on all of conduits 16 in order to provide for
uniform distribution of weight thereto. Also, it is preferable that
grate 18 be freely removable from supporting engagement with
conduits 16, but may, if desired, be permanently attached thereto
as by spot welding. Also, if desired, the construction of grate 18
may depart from that specifically illustrated in the drawings.
It will be noted that a U-shaped construction and mode of
supporting conduits 16 provides for a relatively rigid, but low
cost construction. Additionally, by arranging the conduits in a
spaced parallel relationship to extend rearwardly of and in a right
angular relationship relative to manifold 12, and by making grate
18 removable, periodic cleaning or removal of ashes from between
the heat transfer conduits may be accomplished without removal of
the entire unit from within the fireplace. An equally important
feature of the construction and arrangement of the conduits is that
it serves to maximize the residence time of air passing through the
heat exchange conduits, whereby to achieve a maximum heating
efficiency for a given capacity blower unit.
In operation, blower unit 14 serves to draw in room air and supply
same under a slight positive pressure to manifold 12, which in turn
serves to distribute air to the air inlet ends of lower leg
portions 42 for subsequent heating and discharge back into the room
through the air outlet ends of upper leg portion 44. During use,
burning logs and large embers are supported by grate 18 for both
radiation and conductive heat exchange relationship with upper leg
portions 44. As time progresses, small embers pass through the
openings of grate 18 whereupon they are placed in immediate
proximity for heat exchange relationship with lower leg portions
42.
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