IMPROVEMENTS IN OPEN FIRE-
Year: 1881

page_text: LETTERS PATENT to John Cornforth, of Birmingham, in the County of
Warwick, Mechanical Engineer, and Edward Theodore Burton, of Birmingham
aforesaid, Surgeon, for an Invention of IMPROVEMENTS IN OPEN FIRE-
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PROVISIONAL SPECIFICATION left by the said John Cornforth and Edward
Theodore Burton at the Office of the Commissioners of Patents on the
14th July 1881.
JOHN CORNFORTH, of Birmingham, in the County of Warwick, Mechanical
Engineer, and EDWARD THEODORE BURTON, of Birmingham_aforesaid, Surgeon.
"IMPROVEMENTS IN OPEN FIRE-CRATES, AND IN COOKING RANGES FOR OPEN
FIRE-GRATES."
Our Invention consists of the construction and arrangement hereinafter described
of the parts of open fire grates, and cooking ranges for open fire grates, whereby
perfect combustion and consequently economy of fuel is secured in the open fire
grates in conjunction with an efficient cooking range.
In constructing an open fire grate according to our Invention, we make the bars
constituting the bottom of the grate hollow or tubular. The said hollow or
tubular bottom bars are open at their front ends, and at the back of the grate open
into vertical channels constituting continuations of the tubular fire bars. These
vertical channels rise to a height about equal to that of the front of the grate, and
being open at top constitute a hollow or perforated bridge through which currents
of hot air from the bottom tubular fire bars rise.
The flame and volatile matter rising from the burning fuel passing over the
perforated bridge and mingling with the hot air delivered by the said bridge, the
unburned matter is effectually oxidised and the maximum heat is obtained, and
smoke at the same time suppressed. In order the more effectually to mix the
gaseous matter rising from the fuel with the heated air delivered by the bridge, one
or more small openings are made at or near the bridge through which jets or streams
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page_text: of cold air enter. These jets strike upon the mingling currents from the fuel and
hollow bridge respectively, and thereby cause their more intimate mixture.
The products of combustion pass out at the back of the grate in a nearly
horizontal direction into a vertical flue fixed in the ordinary chimney. This flue
opens at top into a chamber in which an oven or cooking range is fixed, and the
heated air delivered under the middle of the bottom of this oven spreads to the
sides and back, and converging over the top of the oven enter a vertical flue which
opens into the ordinary chimney. The front of the oven or cooking range has
doors which open either over the chimney piece or in the recess at the back of the
grate.
The hollow bridge may have at bottom a door opening into the ash hole. This
door not only permits of the clearing out of the hollow bridge, but by being opened
more or less wide allows the entrance of cold air into the hollow bridge. When it
is wished to moderate the heat, it may be easily and quickly effected by the
partial opening of the said door.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Cornforth and Edward Theodore Burton in the Great 'Seal
Patent Office on the 7th January 1882.
JOHN CORNFORTH, of Birmingham, in the County of Warwick, Mechanical
Engineer, and EDWARD THEODORE BURTON, of Birmingham aforesaid, Surgeon.
'IMPROVEMENTS IN OPEN FIRE GRATES, AND IN COOKING RANGES FOR OPEN
FIRE GRATES."
Our Invention consists of the construction and arrangement hereinafter described
of the parts of open fire grates, and cooking ranges for open fire grates, whereby
perfect combustion and consequently economy of fuel is secured in the open fire
grates in conjunction where required with an efficient cooking range.
In constructing an open fire grate according to our Invention we make the bars
constituting the bottom of the grate hollow or tubular. The said hollow or tubular
bottom bars are open at their front ends, and at the back of the grate open into
vertical channels constituting continuations of the tubular fire bars. These vertical
channels rise to a height about equal to that of the front of the grate, and being
open at top constitute a hollow or perforated bridge through which currents of hot
air from the bottom tubular fire bars rise.
The flame and volatile matter rising from the burning fuel passing over the
perforated bridge, and mingling with the hot air delivered by the said bridge, the
unburned matter is effectually oxidised and the maximum heat is obtained, and
smoke at the same time suppressed. In order the more effectually to mix the
gascous matter rising from the fuel with the heated air delivered by the bridge,
one or more small openings are made at or near the bridge through which jets or
streams of cold air enter. These jets strike upon the mingling currents from the
fuel and hollow bridge respectively, and thereby cause their more intimate
mixture.
The products of combustion pass out at the back of the grate in a nearly
horizontal direction into a vertical flue fixed in the ordinary chimney. This flue
opens at top into a chamber in which an oven or cooking range is fixed, and the
heated air delivered under the middle of the bottom of this oven spreads to the
sides and back, and converging over the top of the oven enters a vertical flue which
opens into the ordinary chimney. The front of the oven or cooking range has doors,
which open either over the chimney piece or in the recess at the back of the
grate.
The hollow bridge may have at bottom a door opening into the ash hole. This
door not only permits of the clearing out of the hollow bridge, but by being opened
more or less wide allows the entrance of cold air into the hollow bridge. When it
is wished to moderate the heat it may be easily and quickly effected by the partial
opening of the said door.
We will now proceed to describe with reference to the accompanying Drawing
the manner in which our Invention is to be performed.
Figure 1 represents in front elevation, and Figure 2 in cross section an open
fire grate constructed according to our Invention.
The same letters of reference indicate the same parts in the several Figures of
the Drawing.
a, a, are the hollow or tubular fire bars constituting the bottom of the grate b.
One of the hollow fire bars is represented detached in Figure 8. The said tubular fire
bars a are open at their front ends, and their back or inner ends open into vertical
channels at c. These channels consist of a series of vertical divisions or chambers
made in a block or slab fixed at the back of the fire grate b, and constitute

page_text: a perforated bridge, shown separately in perspective, drawn to a smaller scale in
Figure 3. The lower end of the said bridge is furnished with sockets opening into
the vertical channels. Into these sockets the inner ends of the tubular fire bars a, a,
are fixed. The construction of the-perforated bridge c will be best understood by
.an examination of the said Figure 3. The tops of the vertical channels of the
perforated bridge c open into the vertical flue d, and the latter into the chimney d².
By enclosing the top of the perforated bridge c by the flue d, the cold air in the
chimney is prevented from coming into contact with the gases or gaseous matter
delivered over the said bridge. The top of the flue d may open into the chimney
from one foot to six feet above the fire grate. The perforated bridge c may be
made of any fire resisting material, and the tubular fire bars a, a, are made
by preference of cast or wrought iron. The bridge c instead of being made with a
series of divisions or chambers may be made with a single chamber that is of a
hollow or box form.
As the cold air passes along the hollow fire bars a, a, it becomes heated by
contact therewith, and rising up the channels in the perforated bridge c becomes
further heated and the currents of air thus heated are delivered at the top of the
said bridge. The flame and volatile matter rising from the burning fuel in the
grate b pass over the top of the perforated bridge c, and mingling with the hot air
delivered by the said bridge, the unburned matter is effectually oxidised, and the
maximum heat is obtained, and the smoke at the same time suppressed.
At the upper back part of the grate b we construct two arches marked
respectively e and f. The space between the two arches e, f, constitutes a flue or
channel opening over the perforated bridge c, and the space under the arch f also
opens over the perforated bridge c. The back ends of the arches also open into
the vertical flue d in the chimney. The smoke and unconsumed gases principally
from the surface of the fire are conducted between the arches e, f, to the bridge
and into the vertical flue d, while the bulk of the smoke and unconsumed gases
from the body of the fire pass under the arch f to the bridge c, as will be
understood by an examination of Figure 2.
The unconsumed gases and smoke from the body of the fire may be conducted
to the top of the perforated bridge c, and those from the surface of the fire to the
flue d in the chimney in the manner illustrated in front elevation in Figure 4, and
section in Figure 5. In this arrangement a baffle plate g is stationed at the front
of the bridge c forming a flue or channel between it and the bridge. The gases
and smoke from the surface of the fire are in this arrangement conducted by the
arches e, f, into the flue d at a distance from the top of the perforated bridge c,
and the gases and smoke from the body of the fire pass to the perforated bridge c
The two
through the open ends of the baffle plate g, as indicated by the arrows.
currents of volatile matters from the fire thus enter the flue dat different levels.
where they mingle with the hot air delivered into the flue d by the perforated
bridge c.
Or the gaseous matter and smoke from the fire may be conducted directly over
the perforated bridge c and into the flue d in the chimney in the manner
illustrated in front elevation in Figure 6, and vertical section in Figure 7. In this
arrangement slots or openings at h, i, are made in the flue d through which the
gaseous matter and smoke from the fire enter the said flue to be oxidised as they
pass over the perforated bridge c, as will be understood by an examination of
Figure 7.
At the back of the bridge c of each of the arrangements represented is a series
of notches or narrow passages ke, opening into the divisions or chambers of the said
bridge c and also opening into the ashpit. Through these passages a series of jets
of cold air enter the perforated bridge c and strike the mingling currents of hot
air and gaseous matter from the fire at the top of the said bridge, causing à very
effectual mixing of the said hot air and gases, and consequently the perfect com-
bustion of the gases from the fire. The cold air introduced at the passages k, k,
may be conducted to and delivered at the top of the bridge.

page_text: The notches or passages k, k, in the back of the hollow or perforated bridge c are
best seen in the perspective view of the said bridge, shown in Figure 10, and in the
said bridge laid on its face, shown in Figure 11.
In combining a cooking range with an open fire grate constructed as described,
we place at the top of the flue d, up which the heated air and products of
combustion pass from the fire, a chamber in which an oven or cooking range is
fixed. The heated air rising up the flue dis delivered into the said chamber under
the middle of the bottom of the oven from which part it spreads to the sides and
back, and rising, converges over the top of the oven and enters a vertical flue
or a series of collecting flues m represented in Figure 12, which flues m open into
the ordinary chimney. Access to the oven is gained by doors at front over the
mantel piece.
The hollow or perforated bridge of the open fire grate or combined open fire
grate and kitchen range, may be provided with a door 8, represented in Figure 9,
opening into the ash pit. By means of this door the hollow or perforated bridge
may be cleared out, and cold air allowed to enter the hollow or perforated bridge
when required.
Having now described the nature of our Invention and the manner in which
the same is to be performed, we wish it to be understood that we claim as our
Invention of "Improvements in Open Fire Grates and in Cooking Ranges for
Open Fire Grates,"
First. The combination or arrangement, herein before described and illustrated
in the accompanying Drawing, of hollow or tubular fire bars and a hollow or
perforated bridge, whereby perfect combustion of the gaseous products of the fuel
is effected, smoke prevented, and fuel economized.
Secondly. The aperture or apertures at the back of the hollow or perforated
bridge for admitting cold air at or near the point where the hot air from the hollow
or perforated bridge and the gaseous matter from the fire are mixed for the purpose
of effecting the more intimate mixture of the said hot air and gaseous matter,
substantially as herein before described and illustrated in the accompanying
Drawing.
Thirdly. The employment of a flue within the ordinary chimney into which
flue the burning mixture of hot air and gaseous matter from the fire is conducted,
substantially as herein before described and illustrated in the accompanying
Drawing.
Fourthly. The arches by which the gaseous matter from the front and back of
the fire is conducted over the perforated or hollow bridge into the flue in
the chimney, substantially as herein before described and illustrated in the
accompanying Drawing.
Lastly. Constructing and arranging in combination with an open fire grate of
the kinds described and illustrated, an oven or cooking range above the mantel
piece as herein described and illustrated in the accompanying Drawing.
In witness whereof, I, the said Edward Theodore Burton, have hereunto set
my hand and seal, this Sixth day of January, in the year of our Lord
One thousand eight hundred and eighty two.
Vitness,
RICHARD SKERRETT,
37, Temple Street,
Birmingham.
EDWARD THEODORE BURTON. (L.S.)