IMPROVEMENTS IN OVENS FOR FIRING POTTERY, GLASS, AND OTHER SUB- STANCES
Year: 1873

page_text: LETTERS PATENT to Thomas William Minton, of Stoke-upon-Trent,
in the County of Stafford, Manufacturer, for the Invention of
"IMPROVEMENTS IN OVENS FOR FIRING POTTERY, GLASS, AND OTHER SUB-
STANCES."
Sealed the 3rd October 1873, and dated the 10th May 1873.
PROVISIONAL SPECIFICATION left by the said Thomas William
Minton at the Office of the Commissioners of Patents, with his
Petition, on the 10th May 1873.
I, THOMAS WILLIAM MINTON, of Stoke-upon-Trent, in the County of
Stafford, Manufacturer, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN OVENS FOR FIRING POTTERY, GLASS, AND OTHER
SUBSTANCES," to be as follows:-
-
This Invention has for its object to improve the construction of ovens
for firing pottery, glass, and other substances.
In the Drawings hereunto annexed various views are shewn of the
improved oven, the characteristics of which are that the fuel is burnt in

page_text: وو
the inside or "hold
of the oven, the ordinary outer mouths or feeders
being dispensed with, and also that the waste heat can be used for
hardening the decoration on the ware.
In the Drawings A, A, are the fire-bars placed inside the "hold" of
the oven and at the bottom of the ordinary "bags" B which rise up t
just inside the oven walls. C, C, are flues passing away from various
parts of the oven bottom. These flues are led upwards into a chamber
D, which is built upon the top of the oven, and into which the decorated
ware to be hardened is placed. The heated gases pass off from the oven
by the flues C into the chamber D, and thereby heat it. E is a fluc 1
leading away from the centre of the oven bottom, and through which
some of the heated gases may be led away when it is desired to cool the
oven.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas William Minton in tho Great Seal Patent
Office on the 8th November 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
WILLIAM MINTON, of Stoke-upon-Trent, in the County of Stafford,
Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her ;
Letters Patent, bearing date the Tenth day of May, in the year of
our Lord One thousand cight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Thomas William Minton, Her
special license that I, the said Thomas William Minton, my execu- 2
tors, administrators, and assigns, or such others as I, the said Thomas
William Minton, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to timo and at all
times thereafter, during the term therein expressed, should and lawfully
might make, use, excrcise, and vend, within the United Kingdom of 3
Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN OVENS FOR FIRING POTTERY, GLASS, AND
OTHER SUBSTANCES," upon the condition (amongst others) that I, the said

page_text: Thomas William Minton, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and scals,
should particularly describe and ascertain the nature of the said Inven-
tion, 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 Thomas William Minton, 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 :-
This Invention has for its object to improve the construction of ovens
for firing pottery, glass, and other substances.
In the ovens previously in use the fuel is burnt in feeders or mouths
disposed partly on the outer circumference of the oven and partly under
the walls of the same, by which arrangement the greatest portion of the
heat radiating from the coke, and a portion also of that given by the
gases generated by the coals, has no other effect than to heat the
surrounding brickwork without any direct action on the ware to be
baked.
In the improved oven the old feeders or mouths are dispensed with,
the combustion of the coals being entirely effected inside or in the hold
of this oven, so that the heat from the coke or the gases has a more
direct effect on the saggers containing the ware with which it comes in
contact; thus a considerable reduction in tlic quantity of fuel required
to fire the ordinary ovens is realised. Besides, by the addition of a second
chamber on the top of the oven use can be made of the heat that might
escape from the lower part for hardening the printed ware or firing those
articles of pottery for which a low heat is necessary, avoiding besides the
necessity of surrounding the ovens by a second building called hovel.
In this way an economy of space and money is effected.
In the Drawings annexed Figure 1 is a vertical section and Figure 2 a
sectional plan of an oven constructed according to my Invention.
Figures 3, 4, and 5 shew some of the parts separately.
a, a, are the firc-bars; bb, the doors through which the fuel is
supplied; c, c, the fire-places or bags in which the combustion takes

page_text: place, and in the lower front of which some loose bricks d are placed to
prevent the coals falling in ash-pits e, e. When the oven is firing the
flame produced in these bags is directed by means of four or five open
saggers ff, towards the upper part of the oven, and as there is no
opening in the vault through which the heat might escape the flame is
compelled to travel in a downward direction to reach the floor g, g,
where a number of openings h, h, are disposed. These openings give
access to several horizontal flues i, i, and from these the gases reach the
upper chamber in passing through the upright flues j, j, existing in the
thickness of the walls. From the second chamber the final escape of
the gases is effected by the outer chimney k.
At various heights above the doors used for the supply of coals the
small openings m, m, m, have for object to introduce the quantity of air.
necessary to effect a perfect combustion, and they are regulated according
to the quality of fuel. The cooling flue L which communicates outside
is kept shut all the time the oven is firing, and is open afterwards to
assist in cooling. The damper M in the centre of the vault is also
removed after the firing for the same object. Access to the upper
chamber is provided by the door N, and the brackets o, o, o, built in the
inner circumference are intended for placing the printed ware which has
to be hardened. Another object of this upper chamber is to collect the
gases from the upright flues j, j, so that the outer chimney acting on
all of them at the same time equalizes the draught of those which might
be backward or in advance. By reducing the diameter of this outer
chimney the flame may be brought into the second chamber, or by
enlarging it a complete combustion may be effected in the lower part of
the oven, so that carbonic acid only will be found in the upper
chamber.
If in constructing an oven it is desired to suppress this upper chamber
the upright flucs j, j, are omitted, and the gases passing in the flues h, h,
are directed to a central opening similar to L, enlarged from which they
are sent to an outside chimney which will act for several of these
ovens.
Having thus described the nature of my said Invention and the
manner of performing the same, I would have it understood that I claim
the construction of ovens for firing pottery, glass, and other substances,

page_text: substantially as described, and either with or without an upper
chamber.
In witness whereof, I, the said Thomas William Minton, have
hereunto set my hand and seal, this Fifth day of November, in
the year of our Lord One thousand eight hundred and seventy-
threc.