AN IMPROVED THROAT AND DOOR FOR CHIMNEYS AND FLUES
Year: 1858

page_text: LETTERS PATENT to John Billing, of Abingdon Street, Westminster, in
the County of Middlesex, Architect, for the Invention of "AN IMPROVED
THROAT AND DOOR FOR CHIMNEYS AND FLUES."
PROVISIONAL SPECIFICATION left by the said John Billing at the Office
of the Commissioners of Patents, with his Petition, on the 1st March
1858.
I, JOHN BILLING, of Abingdon Street, Westminster, in the County of
Middlesex, Architect, do hereby declare the nature of the said Invention for
"AN IMPROVED THROAT AND DOOR FOR CHIMNEYS AND FLUES," to be as follows:-
I construct a double conical throat or frame of iron, or of pottery, or
enamelled iron, or other suitable material, which I fix or build into the
chimney above or upon the fire-place. A door or valve is made to fit into
this throat, and is connected to it by a joint or hinge, and is provided with a
rod or handle by which it can be raised or lowered. I make this door and
its frame curved, or level, and elliptical, or longer in one direction than in the
other, and I make the joint in such manner that the door may be taken out
and replaced by another if required. The edges of the door and its seat may:
be bevilled, or they may be of spherical or ellipsoidal form, so as to insure a
sufficiently close fit. Any slight interstice between them will soon be. filled>
by soot falling upon it, as the form of the frame directs the soot to it. These":
doors are intended to be shut when the fire-place is out of use, and to be:
opened either to their full extent. or partially when the fire-place is in use;

page_text: for this purpose they may be raised and lowered by a rod with holes, or loops,
or notches, which catch upon a fixed pin, or by other similar means. These
throats and doors may also be applied to flues used for ventilation.
SPECIFICATION in pursuance of, the conditions of the Letters Patent, filed
by the said John Billing in the Great Seal Patent Office on the 1st
September 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
BILLING, of Abingdon Street, Westminster, in the County of Middlesex,
Architect, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of March, in the year of our Lord
One thousand eight hundred and fifty-eight, in the twenty-first year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said John Billing, Her special licence that I, the said John Billing, my
executors, administrators, and assigns, or such others as I, the said John
Billing, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make,, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "AN IMPROVED THROAT AND DOOR
FOR CHIMNEYS AND FLUES," upon the condition (amongst others) that I, the
said John Billing, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately after
the date of the said Letters Patent...
NOW KNOW YE, that I, the said John Billing, do hereby declare the
nature of the said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement
thereof, that is to say:―
I construct a double conical throat or frame of iron, or of pottery, or
enamelled iron, or other suitable material, which I fix or build into the chimney
above or upon the fire-place; a door or valve is made to fit into this throat,
and is connected to it by a joint or hinge, and is provided with a rod or
handle by which it can be raised or lowered. I make this door and its frame

page_text: curved or-level and elliptical, or longer in one direction than in the other, and':
I make the joint in such manner that the door may be taken out and replaced'
by another if required. The edges of the door and its seat may be bévilled, or.
they may be of spherical or ellipsoidal form, so as to ensure a sufficiently close
5.fit.. Any slight interstice between them will soon be filled by soot falling
upon it, as the form of the frame directs the soot to it. These doors are
intended to be shut when the fire-place is out of use, and to
their full extent or partially when the fire-place is in use; for this purpose:
they may be raised and lowered by a rod with holes, or loops, or notches, which:
.catch upon a fixed pin, or by other similar means. These throats and doors
may also be applied to flues used for ventilation.
be open either to.
Figure 1 of the, accompanying Drawing is a longitudinal section of a throat
and door constructed according to my Invention; Figure 2 is a transverse
section, and Figure 3 is a plan of the same.. The same letters refer to similar.
'parts in each Figure.
A is the double conical throat, made of terra-cotta or fire-clay; B is the
door, which is an elliptical plate of wrought iron and lies on a shoulder in the
throat. a, a, are two stout iron wires the ends of which pass through holes
in the terra-cotta, and are secured by bending them or by pouring a little
melted lead into the holes; b is an iron rod rivetted to the plate B, and pro-
jecting at each end under the wires a, a; C is a bent iron rod with two
branches c, c, the ends of which are bent at right angles and enter two staples
d, d, rivetted to the plate B; they can be detached by springing the branches
c, c, past each other. The lower end of this rod or handle C is flattened or
. chisel-shaped, and it rests, when in use, in one of the spaces of a rack, or of
a series of notches or recesses in the back of the grate or stove. When the
chimney is out of use the door B lies on the shoulder of the throat; any soot
which may fall down the chimney is guided by the upper cone to the edge of
the plate B, and thus serves to close any slight interstices between the plate
and the throat, and prevent the descent of cold draughts or smoke from
adjoining chimneys. When the chimney is in use the plate is pushed up by
the handle C, which raises it till the bar breaches the bend of the wires 'a, a;
by pushing the handle C up still further the door is opened to any required.
angle, or may be raised to a vertical position if desired. By this construction.
the door is prevented from striking against the upper cone and from becoming
hinge-bound by the accumulation of soot, as the door first rises in a horizontal
position, or nearly so, and afterwards assumes the angular or vertical position.
When it is required to remove the door the handle C is detached by springing
its. two branches out of the staples-d,-d; the plate B is then lifted at one end

page_text: so as to raise one end of the bar b to the top of the wire a, while the other
end of the bar b remains at or near the bottom of its wire a; in this position
one end of the bar b can be disengaged from the wire a, and the other end
can then be drawn out from the other wire a; the door is thus detached from
the throat, but to remove it entirely it has to be passed through the throat.
This is effected by turning the door so as to bring the smaller diameter of the
elliptical door in a line with or nearly in the direction of the greater diameter
of the throat, through which the door is then passed. A new door, can be
introduced by reversing these operations.
The door, as shewn in Figures 1, 2, and 3, is flat, and rests upon a flat
surface, but it may be made with bevilled edges, as shewu in section in Figure
4, and may fit into the conical part of the throat A. Any soot which falls on
the junction assists in making it air-tight. The door may also be made
elliptical in plan, but with its edge of a spherical form, and it may then be
ground into its seat, which will be of a corresponding spherical form. The
edge of the door will then be of a curved form somewhat resembling the brim
of a hat, being of the form produced by drawing an oval or ellipse on the
surface of a sphere. The throat has been described as made of terra cotta,
but it and the door may be of cast iron or other suitable material.
When the chimney is larger than the throat, the slope of the cones may
be continued by brickwork or other material until they meet the sides of the
chimney, so that there may be no large spaces for the lodgment of soot. I
have described the throat as of a double conical form, but it is hardly necessary
to say that the cones are not mathematically exact, being, elliptical in plan, or
longer in one direction than in the other. It is not necessary that the throat
and door should be of truly elliptical form in plan, as they may have straight
sides and rounded ends, or straight sides and ends, or may be of other forms,
provided that the door and the aperture in the throat are longer in one
direction than in another, so as to admit of the door being passed through the
throat and yet fitting closely, and resting on a seat when in its place.
The construction of the joint or hinge admits of variation; that shewn in the
Drawing is efficient and easily constructed. The wires may be rivetted or
may be cast in when the throat is made of metal, or may be otherwise fixed.
The form and construction of the handle or rod for raising the door may be
varied, and the door may be raised by a rod connected to one arm of a bent
lever or bell crank, the other arm of which is 'moved by a screw, or other
means may be employed for raising and lowering and adjusting the position of
the door.
My improved throat and door possess several advantages over those

page_text: ordinarily used. The double conical form of the throat is well adapted for
guiding the smoke or products of combustion into the chimney, and does not
obstruct the operation of sweeping the chimney. The door when closed lies
upon any small quantity of soot which may have lodged on the shoulder, and
is rendered still more air-tight by any soot which may fall upon it. The
elliptical or elongated form of the door and throat allows of the door being
passed through the throat when required. The construction of the joint or
binge allows of the door being detached and replaced by another if necessary.
The whole can be manufactured at a moderate cost.
Having now described the nature of my Invention, and in what manner the
same is to be performed, I wish it to be understood that what I claim is,
constructing a double conical chimney throat or flue throat of elliptical form
in plan, or longer in one direction than in another, in combination with a
door of corresponding form, as herein-before described; and I also claim
connecting such chimney throats or flue throats and doors by a joint or hinge
of the construction herein-before described, so as to admit of the door being
first raised in a horizontal position, or nearly so, and also to admit of its being
taken out and replaced by another if required.
In witness whereof, I, the said John Billing, have hereunto set my hand
and seal, this Thirty-first day of August, in the year of our Lord One
thousand eight hundred and fifty-eight.
Witness,
CHARLES COWPER,
20, Southampton Buildings,
Chancery Lane, London.
JNO. BILLING. (L.S.)