AN IMPROVEMENT OR IMPROVEMENTS IN MOULDS TO BE USED FOR CASTING STEEL OR HOMOGENEOUS IRON
Year: 1863

page_text: LETTERS PATENT to Robert Mushet, of Coleford, in the County of
Gloucester, Metallurgist, for the Invention of "AN IMPROVEMENT OR
IMPROVEMENTS IN MOULDS TO BE USED FOR CASTING STEEL OR HOMOGENEOUS
IRON."
Sealed the 18th September 1863, and dated the 30th March 1863.
PROVISIONAL SPECIFICATION left by the said Robert Mushet at the
Office of the Commissioners of Patents, with his Petition, on the
⚫ 30th March 1863.
I, ROBERT MUSHET, of Coleford, in the County of Gloucester, Metallurgist,
do hereby declare the nature of tho said Invention for "AN IMPROVEMENT
OR IMPROVEMENTS IN MOULDS TO BE USED FOR CASTING STEEL OR HOMOGENEOUS
IRON," to be as follows:-
My Invention consists in making moulds in which steel or homogeneous iron
articles, such for instance as wheel tyres or cylinders, are to be cast or moulded
either wholly or mainly of sheet iron. When a hollow cylinder of steel or
homogeneous iron is to be cast I make a sheet iron hollow cylinder of the same
external diameter as the internal diameter of the steel or homogeneous iron
cylinder which is to be cast, but three or four inches higher than the said hollow

page_text: cylinder to be cast. This hollow cylinder of sheet iron forms the core or inner
part of the mould in which I cast the hollow cylinder of steel or homogeneous
iron. I make also a second hollow cylinder of sheet iron, the internal diameter
of which is equal to the external diameter of the said hollow cylinder, I intend
to cast but three or four inches higher. This hollow cylinder of sheet iron
forms the outer part of the mould, between which and the first-described sheet
iron hollow cylinder or core the steel or the homogeneous iron hollow cylinder
is to be cast, I further prepare a stratum or bed of sand or loam, and upon this
bed I set up the sheet iron hollow cylinders perpendicularly, the lesser hollow
cylinder inside the larger one and concentric therewith, that is, equidistant at
all parts of its circumference from the inner circumference of the larger sheet
iron hollow cylinder. In place of a stratum or bed of sand or loam a plate of
cast iron or steel may be employed on which to set up the sheet iron hollow
cylinders, but in this case the lower ends of the said cylinders should be
inserted into annular grooves countersunk to receive them in the bed plate of
cast iron or steel. I fill the inner sheet iron hollow cylinder with loose sand or
with a loam core, the said core having the general figure of a cylinder, but
divided by planes intersecting one another in the axis of the core. The several
portions of the core have in cross section the figures of sectors of a circle and
are loosely fitted together so as to yield and allow for the shrinkage of the steel
or homogeneous iron hollow cylinder after it has been cast. Around the larger
or exterior sheet iron hollow cylinder and between the said cylinder and the
foundry box in which it is placed, I ram a quantity of sand as firmly as
possible to back up and support the said larger sheet iron hollow cylinder when
the melted steel or homogeneous iron is poured into the mould. Having
thus arranged the two parts of the mould, I cover the annular space between
the inner and the outer parts of the said mould with a covering of loam
or with a cast-iron plate, leaving one or two gates or openings through which
to pour the melted steel or homogeneous iron into the mould, and I also
make or leave in the said covering air holes for the escape of any steam
or gases which may be generated. The gates through which I pour in the
melted steel or homogeneous iron are made of loam raised five or six
inches above the top of the mould so that a bead of metal may be obtained in
order to ensure the mould being well and completely filled. When the interior
hollow sheet iron cylinder is of considerable diameter, as for a wheel tyre
annular ingot, I employ a loam core composed of sectors set up within the
interior hollow sheet iron cylinder. The number of the sectors may be varied,
but from four to six or eight sectors according to the diameter of the core are
I find sufficient. The sectors of the loam core are set up so as to have from

page_text: one-eighth to three-eighths of an inch between any two sectors, and are arranged
like the staves of a cask or a bucket, and the pressure of the contracting metal
crushes the interior hollow sheet iron cylinder and causes it to contract upon
the loose sectors of the loam core which in their turn also yield and close up
together, thus permitting the cylinder or annular ingot of steel or homogeneous
iron to shrink without risk of tearing or cracking the said cylinder or annular
ingot during the time of its consolidation. In preparing the mould I am
careful to remove from the interior surface of the larger sheet iron hollow
cylinder and from the exterior surface of the smaller sheet iron hollow cylinder
all the scale or oxide of iron, either by scouring or grinding these surfaces or
by cleaning them with acids in the manner practised by tin plate manufac-
turers when preparing iron plates for the tinning process. The object in
cleaning the inner surfaces of the mould being to prevent the melted steel or
homogeneous iron from coming in contact with oxide of iron, which would
cause the generation of gas and occasion cells or honeycombs to be formed
thereby in the surface or body of the hollow cylinders to be cast in the mould.
In casting the hollow cylinder of steel or homogeneous iron I quickly pour
the melted steel or homogeneous iron from the melting pots or ladles in which
it is contained into the sheet iron mould in the ordinary manner through the
gates or channels until the mould is completely filled. In casting an annular
ingot for a wheel tyre I proceed in a similar manner to that already described,
except that the outer part of the mould of sheet iron in place of being of a cylin-
drical figure is made internally of the figure of the external rim of the wheel
tyre intended to be formed from the cast annular ingot. The thickness of the
sheet iron I employ for the manufacture of the moulds may be varied to suit
the size or weight of the casting to be made, but I find in practice that from
one-sixteenth of an inch to three-eighths of an inch in thickness for the sheet
iron answers very well for such castings as are ordinarily required. When
the casting of steel or of homogeneous iron is of considerable size the whole of
the sheet iron mould becomes incorporated with the steel or homogeneous iron,
and sometimes the mould is only attached to the casting, in which case the
adhering sheet iron may be readily chipped or turned off from the surface
of the casting.
The essence of my Invention consists in making moulds to be used for
casting steel or homogeneous iron either wholly or mainly of sheet iron.

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
26th September 1863.
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 Thirtieth day of March, in the year of our Lord One
thousand eight hundred and sixty-three, in the twenty-sixth 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 MOULDS TO BE USED FOR CASTING STEEL OR HOMOGENEOUS IRON," 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 bands 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.
or cylinders, are to be cast or
For convenience of description
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 :-
My Invention consists in making moulds in which steel or homogeneous
iron articles, such for instance as wheel tyres
moulded either wholly or mainly of sheet iron.
I will describe my Invention in connection with moulds for casting hollow
cylinders and annular ingots of steel or homogeneous iron. When a hollow
cylinder of steel or homogeneous iron is to be cast I make a sheet iron hollow
cylinder of the same external diameter as the internal diameter of the steel or
homogeneous iron cylinder which is to be cast, but three or four inches longer
than the said hollow cylinder to be cast. This hollow cylinder of sheet iron
forms the core or inner part of the mould in which I cast the hollow cylinder

page_text: of steel or homogeneous iron. I make also a second hollow cylinder of sheet
iron, the internal diameter of which is equal to the external diameter of the
said hollow cylinder I intend to cast but three or four inches longer. This
hollow cylinder of sheet iron forms the outer part of the mould between which
and the first described sheet iron hollow cylinder or core the steel or the
homogeneous iron hollow cylinder is to be cast. I further prepare a stratum
or bed of sand or loam, and upon this bed I set up the sheet iron hollow
cylinders perpendicularly, the lesser hollow cylinder inside the larger one, and
concentric therewith, that is, equidistant at all parts of its circumference from
the inner circumference of the larger sheet iron hollow cylinder. In place of
a stratum or bed of sand or loam a plate of cast iron or steel may be employed
on which to set up the sheet iron hollow cylinders, but in this case the lower
ends of the said cylinders should be inserted into concentric annular grooves
countersunk to receive them in the bed plate of cast iron or steel. I fill the
inner sheet iron hollow cylinder with loose sand or with a loan core, the said
core having the general figure of a cylinder but divided by planes intersecting
one another in the axis of the core. The several portions of the core have in
cross section the figures of sectors of a circle and are loosely fitted together
so as to yield and allow for the shrinkage of the steel or homogeneous iron
hollow cylinder after it has been cast. The two concentric sheet iron cylinders
are placed in a foundry box. Around the larger or exterior sheet iron hollow
cylinder and between the said cylinder and the foundry box in which it is
placed, I ram a quantity of sand as firmly as possible to back up and support
the said larger sheet iron hollow cylinder when the melted steel or homogeneous
iron is poured into the mould. Having thus arranged the two parts of the
mould I cover the annular space between the inner and the outer parts of the
said mould with a covering of loam or a cast-iron plato leaving one or two
gates or openings through which to pour the melted steel or homogeneous
iron into the mould, and I also make or leave in the said covering air holes
for the escape of any steam or gases which may be generated during the
casting. The gates through which I pour in the melted steel or homogeneous
iron are made of loam raised five or six inches above the top of the mould,
so that a head of metal may be obtained in order to ensure the mould being
well and completely filled. When the interior hollow sheet iron cylinder is of
considerable diameter, as for a wheel tyre annular ingot, I employ a tubular
loam core composed of sectors set up within the interior hollow sheet iron.
cylinder. The number of the sectors may be varied, but from four to six or
eight sectors according to the diameter of the core are I find sufficient. Tho
sectors of the loam core are set up so as not to be in contact but distant from

page_text: each other from one-eighth to three-eighths of an inch, and are arranged like
the staves of a cask or a bucket, and the pressure of the contracting metal
crushes the interior hollow sheet iron cylinder and causes it to contract upon
the loose sectors of the loam core, which in their turn also yield and close up
together, thus permitting the cylinder or annular ingot of steel or homogeneous
iron to shrink without risk of tearing or cracking the said cylinder or annular
ingot during the time of its consolidation. In preparing the mould I am
careful to remove from the interior surface of the larger sheet iron hollow
cylinder, and from the exterior surface of the smaller sheet iron hollow cylinder,
all the scale or oxide of iron either by scouring or grinding these surfaces or
by cleaning them with acids in the manner practised by tin plate manufacturers
when preparing iron plates for the tinning process, the object in cleaning the
inner surfaces of the mould being to prevent the melted steel or homogeneous
iron from coming in contact with oxide of iron, which would cause the
generation of gas and occasion cells or honeycombs to be formed thereby in the
surface or body of the hollow cylinders to be cast in the mould. In casting
the hollow cylinder of steel or homogeneous iron I quickly pour the melted
steel or homogeneous iron from the melting pots or ladles in which it is con-
tained into the sheet iron mould in the ordinary manner through the gates or
channels until the mould is completely filled. In casting an annular ingot for
a wheel tyre I proceed in a manner similar to that already described, except
that the outer part of the mould of sheet iron in place of being of a cylindrical
figure is made internally of the figure of the external rim of the wheel tyre
intended to be formed from the cast annular ingot. The thickness of the sheet
iron I employ for the manufacture of the moulds may be varied to suit the
size or weight of the casting to be made, but I find in practice that from one-
sixteenth of an inch to three-eighths of an inch in thickness for the sheet- iron
moulds answers very well for such castings as are ordinarily required. In
forming the hollow cylinders described the sheet iron is bent into the form
of a cylindrical tube, and the edges of the longitudinal seam are secured by
rivets or by lapping the edges in the manner usually practised by manufacturers
of sheet-iron articles. When the casting of steel or of homogeneous iron is of
considerable size the whole of the sheet iron mould becomes incorporated with
the steel or homogeneous iron, and sometimes the mould is only attached to the
casting, in which case the adhering sheet iron may be readily chipped or turned
off from the surface of the casting. Although I have only described my Inven-
tion as applied to moulds for casting hollow cylinders and annular ingots of
cast steel or homogeneous iron, to the casting of which said cylinders and ingots
my said Invention is especially applicable, yet I wish it to be understood that

page_text: my
said Invention is also applicable to moulds for casting hollow articles of
cast steel and homogeneous iron other than the said cylinders and ingots as
well as to moulds for casting articles having a solid figure, but as I believe the
nature of my Invention and the manner in which the same is to be performed
will be understood by the description herein-before given, I do not consider
further details necessary.
The essence of my Invention consists in making moulds to be used for
casting steel or homogeneous iron either wholly or mainly of sheet iron.
In witness whereof, I, the said Robert Mushet, have hereunto set my
hand and seal, this Twenty-third day of September, in the year
Lord One thousand eight hundred and sixty-three.
Witnesses,
EDWP. M. MUSHET,
Cheltenham, Gloucestershire.
B. MUSHET,
Cheltenham, Gloucestershire.
ROBT. MUSHET. (L.S.)