IMPROVEMENTS IN THE CONSTRUCTION OF AIR FURNACES, PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO OTHER FURNACES
Year: 1853

page_text: LETTERS PATENT to Henry Wilkinson, of the firm of Messrs.
Wilkinson, Brass Foundry, Tottenham Mews, for the Invention
of "IMPROVEMENTS IN THE CONSTRUCTION OF AIR FURNACES, PARTS
OF WHICH IMPROVEMENTS ARE APPLICABLE TO OTHER FURNACES."
Sealed the 6th March 1854, and dated the 6th September 1858.
PROVISIONAL SPECIFICATION left by the said Henry Wilkinson
at the Office of the Commissioners of Patents, with his Petition,
on the 6th September 1858.
I, HENRY WILKINSON, of the firm of Messrs. Wilkinson, Brass
Foundry, Tottenham Mews, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE CONSTRUCTION OF AIR FURNACES,
PARTS OF WHICH IMPROVEMENTS ARE APPLICABLE TO OTHER FURNACES," to
be as follows :-
My Invention relates, firstly, to improvements in the construction of
air furnaces for melting metals, &c., and consists in the method herein-
after described of lining the furnace with fire clay or other suitable
material; and, secondly, in the arrangement of a moveable grate for
air and other furnaces, for the purpose of readily clearing the furnace
of slag or other unconsumed matters.

page_text: Fig. 1, on the accompanying Drawing is a plan of the furnace;
and Fig. 2, a section of the same. a, a, are the furnaces, wherein the
crucibles containing the metal to be melted are placed. The fire
brick is built so as to leave a space of two or three inches between
it and the intended size of the furnace. A mould, formed of fillets
of wood, is placed within the furnace, and the space between it and
the furnace filled with a mixture of fire clay and water, which is
allowed to harden, and the mould is withdrawn. When this coating
of fire clay is burnt away or otherwise injured it may be chipped
off to the brickwork, and its place supplied by another. Fig. 3,
represents the form of the mould; the projecting part b, fits the draft
hole c, of the furnace. d, is the brickwork; e, the fire clay coating
or lining; f, iron plates, binding the whole together. g, is an iron
ring, fitting the upper surface of the fire clay; this is covered by a
Welch lump, as shown by h, in the plan, Fig. 1, when the furnace is in
operation.
The arrangement for clearing the grate of scoria is as follows:-
i, is a lever, to which the grate j, supporting the fuel is connected; the
wedge k, which turns on a pin, keeps the grating in its place; when
this is knocked aside the grating falls a certain distance, discharging
the fuel contained in the furnace, and enabling the workman to claim
the bars of anything adhering to them. The iron railing 1, is level
with the floor of the foundry. By means of the flaps m, the workman
has access to the lever i, when it is necessary to clear the grate. n, n,
are steps to facilitate his descent. The draught is regulated by means
of the dampers o, o.
I do not confiue myself to the preciso details herein described and
shown: but substantially the above is a description of my Invention.

page_text: year
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of September, in the
of our Lord One thousand eight hundred and fifty-three, in the seven-
teenth year of Her reign, did, for Herself, Her heirs and succes-
sors, give and grant unto me, the said Henry Wilkinson, Her special
licence that I, the said Henry Wilkinson, my executors, administrators,
and assigns, or such others as I, the said Henry Wilkinson, my exe-
cutors, 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 makė, 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 CONSTRUCTION OF AIR FURNACES, PARTS OF WHICH IMPROVEMENTS ARE
APPLICABLE TO OTHER FURNACES," upon the condition (amongst others) that
I, the said Henry Wilkinson, 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 Henry Wilkinson, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and
by the following statement:
This Invention consists of certain improvements in the construction
of furnaces for melting metals, particularly the description of air fur-
nace used by brass founders for melting the metal required in that
trade, for the reduction of which a very powerful heat is necessary.
Hitherto these furnaces have been built of brick and iron, and the
parts exposed to the heat of the fire of fire brick; the intensity of the
heat, however, soon destroys and burns away the bricks, entailing con-
siderable trouble and loss of time in rebuilding the fire chamber.
Now the object of one part of these improvements is to avoid this
delay and expence by a mode of coating the furnace with glass-
grinder's sand and fire clay, or refuse glass-grinder's sand alone, or other
non-conducting material.

page_text: Another part of these improvements refers to the arrangement of the
bars or grate which support the fuel, which, instead of being fixed, as
in ordinary use, are moveable, and attached to an arm or lever, so that
the fuel can be discharged at once from the furnace and heat stopped.
This arrangement is also useful when the furnace requires repairing, or
when slag accumulates, or to put out the fire when the workman has
done with it.
Fig. 1, of the accompanying Drawing represents a front elevation of
a series of four of the improved furnaces. Fig. 2, is a plan of the same;
Fig. 3, a vertical section of one of the furnaces; and Fig. 4, a view of
the under side of the furnaces, Figs. 1, 2. These Figures are drawn to
a scale of three quarters of an inch to the foot. A, A, are the furnaces,
in which are placed the crucibles containing the metal to be melted.
B, B, Fig. 3, is the fire clay brickwork, in which is left an internal
space C, C, some two or three inches larger on each side than the
diameter of the intended furnace. D, is the draft hole, communicating
with the flue E. A damper F, is fitted in the brickwork of each flue
to regulate the draft. Cast iron plates G, G, are secured to the front
of the furnace by tie rods h. h, which pass through the brickwork; and
on the top of the furnace are placed the plates i, i, which are retained
in their places by a framing of square iron bars k, k, secured by nuts
and screws. Within the framing is placed a Welch lump with a cir-
cular aperture in the centre corresponding in size with the space left
in the brickwork. The top of the furnaces project a few inches above
the level of the flooring, below which a large space or pit L, is cleared
out in front of the furnaces, extending beneath them to the brickwork
of the flues, affording access to the lower part of the furnaces. The
pit is covered by the iron railing M, which is made with flaps M', to
enable the workman to descend. A series of steps m², are fixed in the
brick work forming the side of the pit to facilitate descent and ascent.
The under side of each furnace consists of an iron plate N, with a
circular opening N', Figs. 3, 4, to receive the grating which supports
the fuel and crucible; the plate is supported by the brickwork of the
flue, and by an iron rod o, fixed in the stone paving which forms the
base of the furnaces. The rod o, forms a fulcrum upon which the
grating p, turns.

page_text: Fig. 5, represents a plan of the grating, drawn to a scalo one
fourth the real size. Fig. 6, is a section of the same; and Fig. 7,
a section of the grating, showing the form of the bars. To the circular
grating 9, which fits the aperture N', in the plates N, is fixed an
arm q', which turns upon a pin q", supported by the brackets q³, on
the rod o; thus, by lifting the arm q', the grating q, will descend, dis-
charging the fuel into the space below the furnace, or into a shovel
with a long handle, to obviate the necessity of the workman going below;
the slag may then be removed, and the fuel returned to the furnace.
The grating 1, is held firmly in its place by a wedge or pin 1, fitted in
the lug, which is screwed to the arm 7'; when the grating is in its
place within the opening N', the wedge abuts against the under side
of the furnace. The wedger, turns on a pin which passes through the
lug; and in order to lower the grating the wedge or pin is struck
with a hammer, which causes it to fall aside and liberate the grate.
Figs. 8, 9, represent a grating somewhat different in form to that shewn
by Figs. 5, 6, and 7. Fig. 10, represents an elevation of the mould for
forming the sand and fire clay lining of the furnaces. Fig. 11, is a plan
of the mould for the draft hole. The mould is formed of thin fillets of
wood, screwed to two circular pieces of wood the size of the interior of
the furnace. The mould for the draft hole is made in a similar manner,
or of one piece of wood. A handle should be fitted to the furnace mould,
by which it may be readily withdrawn from the furnace when done
with. Both moulds being properly disposed within the furnace, a
quantity of glass-grinder's sand and fire clay, by preference three parts
of the latter to one part of the former, made into a plastic mass with
water, is to be poured around the moulds, and allowed to harden. The
moulds may then be withdrawn, and the coating completely dried by
the application of heat. The plates and Welch lump are then placed in
their proper positions, and the furnace is ready for use. The coating
of sand or fire clay will. by use, and the intense heat employed, wear
away and require renewing, which may be readily effected by chipping
off the remaining portions of the coating, placing in the moulds and
pouring in a fresh quantity of sand or fire clay and water. By these
means the furnaces may, with little inconvenience or delay, be kept in

page_text: good working order at a very triffing expence. These improvements
are applicable either wholly or in part to other description of furnaces
besides those herein named.
Having described the nature of my Invention, and the manner of
carrying the same into effect, I wish it to be understood that I do not
confine myself to the precise arrangement of the various parts herein
described and referred to, so long as the distinguishing features of my
Invention be adhered to; but what I claim as my Invention, and desire
to secure by these Letters Patent, is,―
Constructing air furnaces with moulded fire chambers and moveable
grates, in the manner and for the purposes herein-before described, and
shewn by the annexed Drawings.
..In witness whercof, I, the said Henry Wilkinson, have hereunto
set my hand and seal, this Sixth day of March, in the year of
our Lord One thousand eight hundred and fifty-four.
H. WILKINSON. (L.S.)