IMPROVEMENTS IN CAST IRON OR IN RENDERING CAST IRON MALLEABLE
Year: 1854

page_text: LETTERS PATENT to Charles Hargrove, of Birmingham, in the County
of Warwick, Manufacturer, for the Invention of "IMPROVEMENTS IN
CAST IRON OR IN RENDERING CAST IRON MALLEABLE."
PROVISIONAL SPECIFICATION left by the said Charles Hargrove at the
Office of the Commissioners of Patents, with his Petition, on the
2nd November 1854.
I, CHARLES HARGROVE, of Birmingham, in the County of Warwick, Manu-
facturer, do hereby declare the nature of the Invention for "IMPROVEMENTS
IN ANNEALING CAST IRON, OR IN RENDERING CAST IRON MALLEABLE," to be as
follows:-
My said Invention consists, firstly, in the substitution of ovens or annealing
chambers made of fire clay or brick, in place of the iron pans usually employed
for containing the articles to be annealed. I make the said chambers of a
height equal to two or three times their width, and place them in a suitable
_furnace, so that the flame and heated air shall circulate all around them, and
raise them to a uniform temperature. One end of each chamber is made open,
and as it is filled up with the articles to be annealed, the said open end is closed
with a temporary door or wall.

page_text: My Invention consists, secondly, in the recovery of the iron ore or oxide used
for annealing iron. For this purpose, I treat the ore or oxide after it has
been used by any of the well-known processes, whereby iron may be raised to
the state of peroxide, and use the said peroxide again for the same purpose.
Ore or oxide of iron thus recovered may be used many times for annealing
cast iron.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Hargrove in the Great Seal Patent Office on the
25th April 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, 1, CHARLES
HARGROVE, of Birmingham, in the County of Warwick, Manufacturer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Second day of November, in the year of our
Lord One thousand eight, hundred and fifty-four, in the eighteenth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Charles Hargrove, Her special licence that I, the said Charles
Hargrove, my executors, administrators, and assigns, or such others as
1, the said Charles Hargrove, 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 ANNEALING CAST IRON, OR IN RENDERING CAST IRON
MALLEABLE," upon the condition (amongst others) that I, the said Charles
Hargrove, 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 Charles Hargrove, 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):-
My Invention consists, firstly, in the substitution of a series of ovens or

page_text: annealing chambers made of fire clay or brick, in place of the iron pans usually
employed for containing the articles to be annealed.
Figure represents in vertical section, and Figure 2 in horizontal section,
a furnace containing ovens or annealing chambers of fire clay or brick made
according to my Invention. The said ovens or chambers are marked a, b, c, d.
1 prefer to make the said chambers of a height equal to two or three times
their width, and of a length equal to five or six times their width; but I do
not limit myself to these proportions. e, e, e, are fire-places, the heated air
from which ascends on one side, and descends on the other side of each
chamber. After descending, the heated air passes along the horizontal flues
,, into the chambers g. 9, at the back of the ovens, whence it escapes by the
flues h, h. The fire-places e, e, e, are supplied by air from the ash-pits i, i, i,
and the hollow bars of the said fire-places are connected with the flues;k, ki,
whereby a current of heated air is delivered by the passages 1, 1, on to the
fire, and the perfect combustion of the fuel is effected. The front portions of
the chambers a, b, c, d, that is to say, the ends marked a, b, c, d, are open,
and the articles to be annealed, and the peroxide of iron in which the articles
are imbedded during the annealing process, are introduced at the said openings,
and as the chambers are filled up, the open ends are closed by temporary
wall. The fires are lighted on the several fire-places e, e, e, and the ovens
raised and maintained at the proper temperature for annealing the articles of
cast iron, and the heat maintained the requisite length of time. After the
annealing ovens or chambers have cooled, the temporary walls are removed
from the ends a, b, c, d, and the annealed articles and the peroxide of
iron removed. The course of the heated air is indicated by the arrows in
Figure 1.
My Invention consists, secondly, in the recovery of the iron ore or peroxide
of iron used for annealing cast iron. The said ore or peroxide of iron suffers
a partial reduction, that is to say, it loses oxygen during the annealing of the
iron; and the object of this part of my Invention is to recover the said ore or
oxide of iron, so as to make it fit for use again. For this purpose, I treat
the ore or oxide after it has been used by the processes herein-after described,
whereby iron may be raised to the state of peroxide, and I use the said per-
oxide again for the same purpose. Ore or oxide of iron thus recovered may be
used many times for annealing cast iron.
The processes I use for carrying this part of my Invention into effect are
the following:-The ore to be recovered may be moistened with water and
exposed to the air; or the said ore may be moistened with dilute hydro-
chloric or nitric acid, and exposed to the air; or it may be treated with

page_text: chlorine, or any of the compounds of chlorine which possess oxidizing properties.
I do not think it necessary to explain the methods of using chlorine and
its compounds for the purpose of raising the iron to the state of peroxide, as
the same are well known; by any of the processes described the used ore or
peroxide may be recovered, and made fit for use again. The method I prefer
is that in which dilute nitric acid is used.
Having thus described the nature of my said Invention,. and the manner of
carrying the same into effect, I wish it to be understood that I do not limit
myself to the precise methods herein described, as the same may be varied
without departing from the nature of my said Invention; but I claim as my
Invention,―
Firstly, the use of a series of ovens or chambers made of fire clay or brick
for annealing articles of cast iron, as herein described, and illustrated in the
accompanying Drawing.
Secondly, the recovery of peroxide of iron or iron ore that has been used for
annealing iron, so as to render the same fit to be used again by any of the
processes herein described.
In witness whereof, 1, the said Charles Hargrove, have hereunto set my
hand and seal, this Twenty-fourth day of April, in the year of our Lord
One thousand eight hundred and fifty-five.
CHARLES HARGROVE. (L.S.)
Witness.
GEORGE SHAW.
CHARLES HARGROVE. (L.S.)