AN IMPROVEMENT OB IMPROVEMENTS IN CASTING INGOTS OF STEEL
Year: 1861

page_text: LETTERS PATENT to Robert Mushet, of Coleford, in the County of
Gloucester, Metallurgist, for the Invention of "AN IMPROVEMENT OB
IMPROVEMENTS IN CASTING INGOTS OF STEEL."
Sealed the 30th July 1861, and dated the 23rd May 1861.
PROVISIONAL SPECIFICATION left by the said Robert Mushet at tho
Office of the Commissioners of Patents, with his Petition, on the 23rd
May 1861.
I, ROBERT MUSHET, of Coleford, in the County of Gloucester, Metallurgist,
do hereby declare the nature of the said Invention for "AN IMPROVEMENT
OR IMPROVEMENTS IN CASTING INGOTS OF STEEL," to be as follows:-
when melted is usually cast or
which the said steel has been
The ingot moulds employed are
In the manufacture of cast steel, the steel
poured from the melting pot or crucible, in
melted, into ingot moulds formed of cast iron.
of various sizes, shapes, and lengths, in order that the manufacturer of steel may
be enabled to obtain ingots of the various sizes and weights he may require.
Ingot moulds most commonly in use have the figure internally of a square or
four-sided prism, the sides being from 2 to 24 inches broad, and the said
moulds are from 20 inches to 42 inches in length internally. A slight aris or
bevil is usually formed upon the inside angular corners of the ingot mould, so
that the ingot when cast is a square prism with its solid edges bevilled off
ongitudinally.

page_text: When steel is very thoroughly melted and heated considerably beyond its
melting temperature, such steel will, when poured into an iron ingot mould,
undergo during its cooling and solidification a considerable degree of shrinkage,
and this shrinkage forms a deep tube or funnel in the upper part of the ingot,
extending downwards from the centre of the ingot top in the form of an
inverted cone, often several inches in depth, and the same thing occurs when
hard steel highly carbonized is melted and poured into iron ingot moulds even
when such highly carbonized steel is not heated considerably beyond its melting
temperature. This funnel is called by steel manufacturers the "pipe" of the
ingot, and cast steel, which when poured into iron moulds forms ingots with
deep central funnels at the tops of the said ingots, is said to "pipe badly."
As the portion of the ingot containing the funnel or pipe when rolled or drawn
out into a bar is necessarily hollow in its axis, such portions of the bar as
contain the pipe are unsound and unmarketable, and the piped ends of the
ingots are therefore either broken off before the ingots are rolled or drawn, or
the piped portions of the rolled or hammered bars are subsequently cut or
broken off. The necessity for breaking off and removing the pipes from the
ingots causes very great waste and loss to the manufacturer, the weight of the
piped portions of the ingots varying from three pounds to twelve pounds for
each ingot, and sometimes even more. To prevent this waste, either partially
or wholly, is the object of my present Invention.
In casting ingots of steel according to my Invention, I proceed in the
following manner:-When tho ingot mould has been placed on its end
in the usual position for receiving the melted steel contained in the
melting pot or crucible, I pour the greater part of the said melted steel
into the ingot mould in the usual manner, taking care, however, that the
melter or workman who pours the steel into the mould shall stop pouring
the said steel when a quantity of it, from two to four pounds in weight,
or thereabouts, yet remains in the melting pot. I now introduce into the
ingot mould a heated pipe of clay or other material, as herein-after ex-
plained, and I set the bottom end of this pipe upon the surface of the
melted steel which has just been poured into the ingot mould, the said
clay pipe being placed on the top of the ingot, and as the shrinkage takes
place in the ingot the melted steel in the clay pipe falls or sinks down and
fills up the pipe or funnel, which would otherwise be formed in the top o
the ingot. The ingot is taken from the ingot mould in the usual manner, and
the steel remaining in the clay pipe and attached to the top of the ingot i
broken off, and the ingot thus cast is without any "pipe" or funnel. The
clay pipes which I employ for my process should be shaped externally so as to

page_text: fit loosely the interior of the ingot mould in order that they may be readily
introduced into the mould and placed upon the top of the melted steel contained'
in the ingot mould, and at the same time they ought not to be too loosely fitted
to the inside dimensions of the ingot mould, otherwise the melted steel will'
rise between the exterior sides of the clay pipe and the interior sides of the`
mould, and which would cause some unnecessary waste of steel and some
inconvenience. Thus, if the ingot mould be 2 inches square inside measure,
with an aris or bevil off each interior angular corner, the clay pipe should be
about 2 inches square, with its corners or external solid edges taken off
longitudinally to fit the corresponding aris of the interior angular corners of
the ingot mould. The length of the clay pipe should be such that when put
into the ingot mould and set upon the top of the melted steel contained in the
ingot mould, the said pipe should reach from the upper surface of the said
melted steel in the ingot mould to the mouth of the ingot mould, or nearly so;
but I do not confine myself to any particular length for the pipes, for the
length may be varied as circumstances may require. In practice, however, I
find that the pipes answer very well when from six to eight inches in length.
The internal diameter of the clay pipe should be from one to two inches; but
I do not confine myself to these specific diameters. I have found, however, in
practice, that clay pipes of from 11 to 12 inches in diameter answer exceedingly
well. The bore of the pipe may be either straight or taper, but when the bore
is taper, the end of the pipe where the bore is the widest should be placed
upon the top of the melted steel contained in the ingot mould. I prefer that'
the clay pipes previously to being used should be heated to a red heat, for the
hotter the clay pipes are when placed upon the top of the melted steel con-
tained in the ingot mould the less apt are they to chill the small quantity of
steel poured into the said clay pipes, and thus hinder it from sinking down and
preventing the formation of the pipe or funnel in the top of the ingot. The
clay pipes may, however, be employed either when cold or when slightly
heated, but the success of the operation is not so certain or complete as when:
the said clay pipes are strongly heated before they are placed upon the tops of
the ingots to be operated upon.
The clay employed for the manufacture of the pipes I employ for my process
may be any common quality of clay, the cheapest which can be procured, and
t should when ground be mixed with about one-fifth of its weight of coke dust
or other carbonaceous matter in order to prevent the pipes from cracking when
heated. When mixed up ready for use the clay may be manufactured into.
pipes of the dimensions required, either by hand or by means of a machine
uch as is employed for the manufacture of draining pipes. The pipes when

page_text: manufactured are to be well dried, and then heated as they are required for
use, but it is not necessary to burn the said pipes in a kiln or otherwise.
Though I have herein described the use of clay pipes only for my process, I
wish it to be understood that the pipes may nevertheless be manufactured from
other materials which may be found suitable, such, for example, as plumbago, 5
coke, or firestone, but I have found that clay pipes, such as I have described,
are very cheap and answer for my purpose exceeding well. A fresh pipe will
be required for each ingot of steel operated upon, for the pipes are almost;
always broken before they can be removed from the tops of the ingots on.
which they are placed. The clay or other pipes previously to being employed: 1
for my process are heated in a fire or furnace or oven to a red heat, and when
ready to be used they are taken out of the fire or oven where they have been
heated, and are taken in a pair of tongs and quickly introduced into the ingot
moulds, and set upon the top or upper surface of the melted steel contained in;
the ingot moulds, as I have herein-before described.
Having thus described the nature of my Invention, and the methods by
which I prefer to carry the said Invention into effect, I hereby declare that the
essence of my Invention consists in preventing, partially or wholly, the waste
occasioned by what is technically called the "piping" of ingots of steel pro-
duced by pouring melted steel into iron moulds, and I effect my purpose by
introducing a heated clay or other pipe into the ingot mould, when nearly the
whole of the melted steel intended to form the ingot has been poured into the
said ingot mould, and I set the said pipe upon the upper surface or top of the
melted steel intended to form the ingot contained in the ingot mould, and I
then pour the residue of the melted steel, amounting to from two to four
pounds in weight or thereabouts remaining in the melting pot into the heated
clay or other pipe, placed as I have described upon the top or upper surface of
the melted steel contained in the ingot mould which is operated upon, and which
said steel forms when solidified an ingot, so that the residue of melted steel
poured into the said clay or other pipe may sink down and prevent the forma
tion of the pipe, funnel, or cavity which would otherwise be formed in the top
of the ingot by the shrinkage of the melted steel composing the said ingot
during the cooling and solidification of the said melted steel. Or the whole of
the steel in the melting pot may be poured into the ingot mould, and a small
portion of steel from another inelting pot may be quickly afterwards poured
into the heated clay or other pipe placed as I have berein-before described
upon the surface or top of the melted steel contained in the ingot mould, and
which melted steel is intended, when solidified, to form an ingot.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Mushet in the Great Seal Patent Office on the
3rd August 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
MUSHET, of Coleford, in the County of Gloucester, Metallurgist, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of May, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Robert Mushet, Her special licence that I, the said Robert Mushet, my
executors, administrators, and assigns, or such others as I, the said Robert
Mushet, 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 "AN IMPROVEMENT OR IMPROVEMENTS
IN CASTING INGOTS OF STEEL," upon the condition (amongst others) that I, the
said Robert Mushet, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, 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 Robert Mushet, 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:-
In the manufacture of cast steel, the steel when melted is usually cast or
poured from the melting pot or crucible in which the said steel has been
melted into ingot moulds of cast iron, and is thereby made into ingots, which
are subsequently hammered or rolled when in a heated state into bars, rods,
plates, or sheets. The ingot moulds employed are of various sizes, shapes,
and lengths, in order that the manufacturer of steel may be enabled to obtain
ingots of the various sizes and weights he may require. Ingot moulds most
commonly in use have the figure internally of a square or four-sided prism,
the sides being from 2 to 24 inches broad, and the said moulds are from 20
inches to 42 inches in length internally. A slight aris or bevil is usually

page_text: formed upon the inside angular corners of the ingot mould, so that the ingot
when cast is a square prism, with its solid edges bevilled off longitudinally, as
is well understood by steel manufacturers.
When steel is very thoroughly melted and heated considerably beyond its
melting temperature, such steel will, when poured into an iron ingot mould,
undergo during its cooling and solidification a considerable degree of shrinkage,
and this shrinkage forms a deep tube or funnel in the upper part of the ingot,
extending downwards from the centre of the ingot top in the form of an
inverted cone, often several inches in depth, and the same thing occurs when
hard steel or steel which is highly carbonised is melted and poured into iron
ingot moulds, even when such highly carbonised steel is not heated con-
siderably beyond its melting temperature. This funnel is called by steel
manufacturers the "pipe" of the ingot, and cast steel, which when poured into
iron moulds forms ingots with deep central funnels at the tops of the said
ingots, is said to "pipe badly." As the portion of the ingot containing-the
funnel or pipe when rolled or drawn out into a bar is necessarily hollow in its
axis, such portions of the bar as contain the pipe are unsound and unmarketable,
and the piped-ends of the ingots are, therefore, either broken off before tho.
ingots are rolled or drawn, or the piped portions of the rolled or hammered
bars are subsequently cut or broken off. The necessity for breaking off and
removing the pipes from the ingots causes very great waste and loss to the
manufacturer, the weight of the piped portions of the ingots varying from
.three pounds to twelve pounds for each ingot, and sometimes even more. Το
prevent this waste, either partially or wholly, is the object of my present
Invention.
In casting ingots of steel according to my Invention, I proceed in the
following manner :-When the ingot mould has been placed on its end in the
usual position for receiving the melted steel contained in the melting pot or
crucible, I pour the greater part of the said melted steel into the ingot mould
in the usual manner, taking care, however, that the melter or workman who
pours the steel into the mould shall stop pouring the said steel when a quantity
of it from two to four pounds in weight, or thereabouts, yet remains in the
melting pot. I now introduce into the ingot mould a heated pipe of clay or
other material, as herein-after explained, and I set the bottom end of this pipe
upon the surface of the melted steel which has just been poured into the ingot
mould, the said clay pipe being supported in its position by the interior sides
of the ingot mould above the top of the ingot. The melter then quickly pours
the steel which remains in the melting pot into the clay pipe placed on the top
of the ingot, and as the shrinkage takes place in the ingot the melted steel in

page_text: the clay pipe falls or sinks down, and by keeping the middle of the upper end
of the ingot full during the solidification of the steel prevents the formation of
a pipe or cavity. The ingot is taken from tho ingot mould in the usual
manner, and the steel remaining in the clay pipe and attached to the upper
end of the ingot is broken off, and the ingot thus cast is without any "pipe" or
funnel. The clay pipes which I employ for my process should be shaped
externally so as to fit loosely the interior of the ingot mould, in order that
they may be readily introduced into the mould and placed upon the top of tho
melted steel contained in the ingot mould, and at the same time they ought
not to be too loosely fitted to the inside dimensions of the ingot mould, other-
wise the melted steel will rise between the exterior sides of the clay pipe and
the interior sides of the mould, and cause some unnecessary waste of steel and
some inconvenience. Thus if the ingot mould be 2½ inches square inside
measure, with an aris or bevil off each interior angular corner, the clay pipe
should be about 2 inches square, with its corners or external solid edges
taken off longitudinally to fit the corresponding aris of the interior angular
corners of the ingot mould. The length of the clay pipe should be such, that
when introduced into the ingot mould and set upon the top of the melted steel
contained in the ingot mould, the said pipe should reach from the upper
surface of the said melted steel in the ingot mould to the mouth of the ingot
mould, or a little above the mouth of the ingot mould; but I do not confine
myself to any particular length for the pipes, for the length may be varied as
circumstances may require. In practice, however, I find that the pipes
answer very well when from six to eight inches in length. The internal.
diameter of the clay pipe should be from one to two inches, but I do not
confine myself to these specific diameters. I have found, however, in practice,
that clay pipes of from 1 to 1 inches in diameter answer exceedingly well.
The bore of the pipe may be either straight or taper, but when the bore is
taper the end of the pipe where the bore is widest should be placed upon the
top of the melted steel contained in the ingot mould. I prefer that the clay
pipes previously to being used should be heated to a red heat, for the hotter
the clay pipes are when placed upon the top of the melted steel contained in
ho ingot mould, the less apt are they to chill the small quantity of steel
poured into the said clay pipes, and thus hinder it from sinking down and
preventing the formation of the pipe or funnel in the top of the ingot. The
lay pipes may, however, be employed either when cold or when slightly
eated, but the success of the operation is most certain or complete when the
aid clay pipes are strongly heated before they are placed upon the tops of the
ngots to be operated upon..

page_text: The clay employed for the manufacture of the pipes I employ for my process
may be any common quality of clay, the cheapest which can be procured, and
it should when ground be mixed with about one-fifth of its bulk of coke dust
or other carbonaceous matter, in order to prevent the pipes from cracking
when heated. When mixed up ready for use, the clay may be manufactured
into pipes of the dimensions required, either by hand or by means of a
machine such as is employed for the manufacture of draining pipes. The
pipes when manufactured are to be well dried, and then heated as they are
required for use, but it is not necessary to burn the said pipes in a kiln or
otherwise.
Though I have herein described the use of clay pipes only for my process,
I wish it to be understood that the pipes may, nevertheless, be manufactured
from other materials which may be found suitable, such, for example, as
plumbago, coke, or firestone, but I have found that_clay pipes such as I have
described are very cheap, and answer for my purposo exceedingly well. A
fresh clay pipe will be required for each ingot of steel operated upon, for the
pipes are almost always broken before they can be removed from the tops of
the ingots on which they are placed. Plumbago pipes may be used repeatedly,
that is, the same plumbago pipo may be used in casting several ingots, but the
said plumbago pipes are costly. The clay or other pipes previously to being
red
employed for my process are heated in a fire or furnace or oven to
heat, and when ready to be used they are taken out of the fire or oven where
they have been heated, and aro taken in a pair of tongs and quickly introduced
into the ingot moulds, and set upon the top or upper surface of the melted
steel contained in the ingot moulds, as I have herein-before described.
Having thus described the nature of my Invention, and the methods by
which I prefer to carry the said Invention into effect, I hereby declare that
the essence of my Invention consists in preventing, partially or wholly, the
waste occasioned by what is technically called the "piping" of ingots of steel,
produced by pouring melted steel into iron ingot moulds, and I effect my
purpose by introducing a heated clay or other pipe into the ingot mould when
nearly the whole of the melted steel intended to form the ingot has been
poured from the melting pot into the said ingot mould, and I set the said pipe
upon the upper surface or top of the melted steel intended to form the ingot
and contained in the ingot mould, and I then pour the residuo of the melted
steel, amounting to from two to four pounds or thereabouts remaining in the
melting pot into the heated clay or other pipe, placed as I have described
upon the top or upper surface of the melted steel contained in the ingo
mould, and which said steel forms when solidified an ingot, so that the residu

page_text: of the melted steel or part of it poured into the said clay or other pipe may
sink down and prevent the formation of the pipe, funnel, or cavity which
would otherwise be formed in the top or upper end of the ingot by the
shrinkage of the melted steel composing the said ingot during the cooling and
solidification of the said melted steel. Or the whole of the steel in the melting
pot may be poured into the ingot mould, and a small portion of steel from
another melting pot may be quickly afterwards poured into the heated clay or
other pipe, placed as I have herein-before described upon the surface or top of
the melted steel contained in the ingot mould, and which melted steel is
intended when solidified to form an ingot. I wish it to be observed that in
place of pouring part of the steel intended to form the ingot into the ingot
mould before introducing the clay pipe, and then subsequently pouring the
residue of the said steel into the clay pipe placed upon the top or surface of
the portion of steel first poured into the ingot mould, the clay pipe may be
first introduced into the ingot mould, and be either held in a pair of tongs, or
be otherwise fixed in the mould, and the whole of the steel contained in the
melting pot, and which is intended to form an ingot, may then be poured
through the clay pipe into the ingot mould, but this method in practice does
not answer nearly so well as the method I have herein-before described,
neither is it so simple and easy to be carried into effect.
In witness whereof, I, the said Robert Mushet, have hereunto set my
band and seal, this First day of August, in the year of our Lord
One thousand eight hundred and sixty-one.
Witnesses,
EDW. M. MUSHET,
Coleford, Gloucestershire.
BROOKLYN MUSHET,
Coleford, Gloucestershire.
ROBT. MUSHET. (L.S.)