IMPROVEMENTS IN THE CONSTRUCTION OF OVENS
Year: 1855

page_text: LETTERS PATENT to John Dupre, of Plymouth, for the Invention of
"IMPROVEMENTS IN THE CONSTRUCTION OF OVENS."-A communication.
Scaled the 4th September 1855, and dated the 12th May 1855.
PROVISIONAL SPECIFICATION left by the said John Dupre at the Office
of the Commissioners of Patents, with his Petition, on the 12th May
1855.
I, JOHN DUPRE, of Plymouth, do hereby declare the nature of the Inven-
tion for "IMPROVEMENTS IN THE CONSTRUCTION OF OVENS " to be as follows:-
This Invention consists of a peculiar construction of oven. For this purpose,
in constructing an oven it is preferred that the base should be rectangular, the
fire bars being arranged in the centre; there is a fire door in front, and there is
a flue from the back end of the fire bars under part of the oven, which opens
into an upright flue which leads to the chimney, and it is provided with a
damper for regulating or closing the draft in that direction. It is preferred
that the oven should be circular. The bottom of the oven has an opening in
the centre over the fire bars, and in the bottoin near the centre there are air
passages, the air circulating through which becomes heated, and such heated
air is admitted into the oven, and is regulated by valves or slides. The roof or

page_text: top of the oven is formed convex at the outside and concave on the inside, and
it has in it four openings, which communicate with flues above, and which
communicate with the upright flue leading to the chimney; these openings
have valves or slides to regulate the passage of air and vapour from the oven.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Dupre in the Great Seal Patent Office on the 3rd
November 1855..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
DUPRE, of Plymouth, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of May, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Dupre, Her special licence that I, tho said John Dupre, my
executors, administrators, and assigns, or such others as I, the said John
Dupre, 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 "IMPROVEMENTS IN THE CON-
STRUCTION OF OVENS," a communication, upon the condition (amongst others)
that I, the said John Dupre, by an instrument in writing under my hand
and seal, 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 Dupre, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof (that is to say):
This Invention consists of a peculiar construction of oven. For this purpose,
in constructing an oven it is preferred that the base should be rectangular, the
fire bars being arranged in the centre; there is a fire door in front, and there

page_text: is a flue from the back end of the fire bars under part of the oven, which opens
into an upright flue which leads to the chimney, and it is provided with a
damper for regulating or closing the draft in that direction. It is preferred
that the oven should be circular. The bottom of the oven has an opening in
the centre over the fire bars, and in the bottom near the centre there are air
passages, the air circulating through which becomes heated, and such heated
air is admitted into the oven, and is regulated by valves or slides. The roof or
top of the oven is formed convex at the outside and concave on the inside, and
it has in it four openings, which communicate with flues above, and which com-
municate with the upright flue leading to the chimney; these openings have
valves or slides to regulate the passages of air and vapour from the oven.
Having thus stated the nature of the said Invention, I will proceed to
describe more fully the manner of performing the same.
DESCRIPTION OF THE DRAWING.
:
Figure 1 is a front view; Figures 2 and 3 are two vertical sections;
Figures 4, 5, and 6 are three horizontal sections, taken respectively at the
different parts of Figure 1, as marked thereon. In each of these Figures the
same letters are used to indicate similar parts. a, a, is the bottom of the oven,
the form of which may be varied; b is a furnace or fire-place below the level
of the bottom of the oven; c, c, are the fire bars; d, the ash-pit; over the fire-
place is an opening e into the oven, and up through which the heat ascends.
From the oven there are several openings into flues e', e', which open into or
communicate with the chimney f. Around the upper part of the opening e is
an air passage g, through which air passes and becomes heated after taking the
steam from boiler, and such heated air is admitted through one or, it may be,
moro passages or flues h; or the heated air may be allowed to pass into the
branch flue without passing into the oven. To each of the flues e, e, there
is a slide or damper &; there is also a valve or damper to the chimney f, by
which the passages may be regulated, as desired. To the flues h and i there
are two slides or dampers j, j, so arranged as to close one passage when the
other is open.
In order to increase the draft, I can, if desired, apply a boiler or vessel k
to contain water, which becoming heated, steam may be raised and allowed to
pass through the flues h, i, or there may be a separate passage and flue to the
chimney.
I would remark, in very large ovens more than one opening over the fire
may be used, or more than one fire and opening may be employed.

page_text: Having thus described the nature of the Invention, and the manner of per-
forming the same, I would have it understood that I make no claim to any
of the parts separately; but what I claim is, the construction or combination
herein described.
In witness whereof, I, the said John Dupre, have hereunto set my hand
and seal, this Thirty-first day of October, in the year of our Lord One
thousand eight hundred and fifty-five.
Witness,
THOMAS H. BULTEEL,
Magistrate for Plymouth.
JOHN DUPRE. (LS.)