IMPROVEMENTS IN THE MANUFACTURE OF CAST STEEL AND OTHER METALS, AND IN THE MAKING OF CASTINGS OF THE SAME.
Year: 1873

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF CAST STEEL AND OTHER METALS,
AND IN THE MAKING OF CASTINGS OF THE SAME. -A communication from
abroad by James Albert Holmes, of the City and County of Phila-
"
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 2nd April 1873.
"
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF CAST STEEL AND OTHER
METALS, AND IN THE MAKING OF CASTINGS OF THE SAME," a communication to
me from abroad by James Albert Holmes, of the City and County of
Philadelphia, State of Pennsylvania, United States of America, to be as
follows:-
This Invention has for its object first to produce ingots of cast steel
and other metals free from the crevices and other imperfections common

page_text: to ingots cast in moulds in the usual manner; secondly, to prevent waste
and deterioration of the metal during the process of melting; and thirdly,
to produce perfect and uniform castings.
The first and second objects are attained by permitting the steel or
other metal to become cool in the hermetically sealed crucible in which 5
it is melted, the crucible being made with one side detachable, or being
provided with a detachable lining, so that the ingot may be removed
without injury to the crucible.
The third object of the Invention is attained by making a series of
moulds in the upper portion of the crucible, so that by simply inverting 1
the crucible after the melting operation the metal will flow into and fill
the moulds in which it is permitted to cool before admitting any air.
It has been ascertained that if the steel or other metal be permitted
to cool in the hermetically sealed crucible in which it is melted the
formation of crevices and smaller cavities will be obviated, and oxidi- 1
zation and waste prevented, but as it would be a difficult matter to
remove the cooled ingot from an ordinary crucible without fracturing
the latter it is advisable to make a special crucible wherewith to carry
out this Invention.
For this purpose the crucible is made with one side detachable, having
bevelled edges adapted to corresponding grooves in the adjacent sides of
the crucible, through which it can be caused to slide. This crucible
after having been filled and closed by a suitable cap and the joints
packed with clay or other refractory material is placed in the usual
furnace, and there remains until its contents are melted, when it is
removed and permitted to become cool, after which the cap is detached
and the slide withdrawn, when the ingot may be readily removed
without injury to the crucible, which can be at once prepared for the
casting of another ingot.
According to another form of special crucible which may be used in
carrying out this Invention the exterior casing, or as it may be termed
the crucible proper, made square or of other section and of the usual
material, contains a detachable lining composed of four vertical slabs, a
base piece, and a cap. Over the upper end of the lining fits a flanged
cover, between which and the sides of a socket formed at the top of the
crucible intervenes a space to be packed with clay or other refractory
material.

page_text: After the melting and cooling of the contents of the lined crucible
the cover may be removed, when the metal with its lining slabs may be
withdrawn and the crucible used again. After withdrawing the cooled
ingot from the crucible the lining slabs may be readily detached from
the same without fracturing and are ready to be used again. It is pre-
ferred to make these slabs of one determined sizo and interchangeable
so that they can be readily replaced when broken.
The interior of the crucible may be separated into any desired number
of compartments by detachable lining slabs.
It is most important that the crucible be hermetically sealed, inasmuch
as the gases are thereby prevented from coming in contact with and
deteriorating the metal, while the latter being preserved from contact
with the air is cooled so gradually that the formation of external crusts
and internal cavities is effectually prevented.
In order that the most perfect castings of a variety of objects free
from flaws and other imperfections may be obtained the cover of the
crucible should be hermetically sealed to the body of the same, and
made of about the same depth as the latter, and within the said cover
are arranged a series of moulds communicating freely with each other,
and with the interior of the crucible by central passages. After the
melting of the metal in the hermetically sealed crucible the latter is
simply inverted, when the metal will run into and fill the moulds in
which it is permitted to cool, when the crucible is opened, and the
objects thus cast removed from the moulds. The latter are of the same
refractory material as the cover and body of the crucible so as not to be
affected by the great heat to which they are subjected during the melting
operation. This method of casting insures uniform and superior results,
for as the air is not brought into contact with the metal there can be no
deterioration of the same or partial cooling before it has entirely filled
the moulds.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 2nd October 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of April, in the year of
our Lord One thousand eight 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 John Henry Johnson, Her special license
that I, the said John Henry Johnson, my executors, administrators,
and assigns, or such others as I, the said John Henry Johnson,
my executors, administrators, or 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 MANUFACTURE OF CAST STEEL AND OTHER METALS, AND IN THE MAKING OF
CASTINGS OF THE SAME," a communication to me from abroad by James
Albert Holmes, of the City and County of Philadelphia, State of Pennsyl-
vania, United States of America, upon the condition (amongst others)
that I, the said John Henry Johnson, my executors or administrators,
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 imme-
diately after the date of the said Letters Patent.
"
NOW KNOW YE, that I, the said John Henry Johnson, 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, reference being had to the accompanying
Drawings and to the letters and figures marked thereon, that is to say :-
The objects of this Invention are first to produce ingots of cast steel
and other metals free from the crevices and other imperfections common
to ingots cast in moulds in the usual manner; secondly, to prevent waste
and deterioration of the metal during the process of melting; and thirdly,
to produce perfect and uniform castings.
The first and second objects are attained by permitting the steel or
other metal to become cool in the hermetically sealed crucible in which
it is melted, the crucible A being made with one side F detachable, as
shown in the perspective view, Figure 1, of the accompanying Drawing,
or being provided with a detachable lining B, as shown in the sectional

page_text: view, Figure 3, so that the ingot may be removed without injury to the
crucible.
The third object of the Invention is attained by making a series of
molds in the upper portion of the crucible, as shown in Figure 5, so that
by simply inverting the crucible after the melting operation the metal
will flow into and fill the molds in which it is permitted to cool before
admitting any air.
C
In casting ingots of steel in moulds in the usual manner a crevice is
formed in the metal during the cooling of the same, this crevice penc-
trating the ingot to a greater or less extent and rendering a great portion
of it unfit for use in the manufacture of objects of steel. The ingot is
also liable to become oxidized and full of small cavities or honey-
combs," as they are sometimes termed. The above is also the case to a
great extent in casting ingots of other metals, and the exposure to the
air both in melting and casting causes a considerable loss of metal both
by vaporizing and oxidizing.
It has been ascertained that if the steel or other metal be permitted
to cool in the hermetically sealed crucible in which it is melted the
formation of crevices and smaller cavities will be obviated, and oxidization
and waste prevented; but as it would be a difficult matter to remove the
cooled ingot from an ordinary crucible without fracturing the latter it
is advisable to make a special crucible wherewith to carry out this
Invention.
In the perspective view Figure 1, and plan view Figure 2 of the
accompanying Drawing, which illustrate the simplest form of this special
crucible, the latter is made with one side F detachable, it having in the
present instance beveled edges adapted to corresponding grooves in the
adjacent sides of the crucible through which it can be caused to slide.
This crucible, after having been filled and closed by a suitable cap and
the joints packed with clay or other refractory material, is placed in the
usual furnace and there remains until its contents are melted, when it is
removed and permitted to become cool, after which the cap is detached
and the slide withdrawn, when the ingot may be readily removed without
injury to the crucible, which can be at once prepared for the casting of
another ingot.
Another form of special crucible which may be used in carrying out

page_text: exterior casing, or as it may be termed the crucible proper made square
in the present instance and of the usual material. This casing or
crucible contains a detachable lining composed of four vertical slabs a,
a base piece b, and a cap
d. Over the upper end of the lining fits a
flanged cover D, between which and the sides of a socket e formed at t
the top of the crucible intervenes a space to be packed with clay or
other refractory material.
After the melting and cooling of the contents of the lined crucible
the cover D may be removed, when the metal with its lining slabs may
be withdrawn and the crucible used again. After withdrawing the cooled 1
ingot from the crucible the lining slabs may be readily detached from
the same without fracturing and are ready to be used again. It is pre-
ferred to make these slabs of one determined size and interchangeable,
so that they can be readily replaced when broken.
The interior of the crucible may be separated into any desired number 1
of compartments by detachable lining slabs. In Figure 4 for instance
the crucible contains four compartments.
It is most important that the crucible be hermetically sealed, inas-
much as the gases are thereby prevented from coming in contact with
and deteriorating the metal, while the latter being preserved from contact 2
with the air is cooled so gradually that the formation of external crusts
and internal cavities is effectually prevented.
Figure 5 represents a plan whereby the most perfect castings of a
variety of objects free from flaws and other imperfections may be
obtained. The cover D of the crucible is hermetically sealed to the 2
body of the same, and is made of about the same depth as the latter,
and within the said cover are arranged a series of molds X communi-
cating freely with each other, and with the interior of the crucible with
passages x. After the melting of the metal in the hermetically sealed
crucible the latter is simply inverted, when the metal will run into and 3
fill the moulds in which it is permitted to cool, when the crucible is
opened and the objects thus cast removed from the molds. The latter
are of the same refractory material as the cover and body of the crucible
so as not to be effected by the great heat to which they are subjected
during the melting operation. This method of casting insures uniform 3.
and superior results, for as the air is not brought into contact with the

page_text: metal there can be no deterioration of the same or partial cooling before
it has entirely filled the moulds.
Having now described and particularly ascertained the nature of the
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that what I consider to
be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is,-
First. The production of ingots of cast steel and other metals by the
process described, namely, melting the metal in an hermetically sealed
crucible and permitting the same to cool in the said crucible, from which
the ingot is removed as set forth.
Secondly. A crucible made with one side detachable, substantially as
and for the purpose described.
Thirdly. A crucible made with detachable linings, substantially as and
3 for the purpose described.
Fourthly. The within described process of casting, that is, by inverting
an hermetically sealed crucible, and thus permitting the molten metal
in the same to run into and fill a mold or molds in the upper portion
or cover of the said crucible.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, this Thirtieth day of
September One thousand eight hundred and seventy-three.