IMPROVEMENTS IN THE MANUFACTURE OF COMPOUND ARMOUR PLATES
Year: 1884

page_text: I JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of said Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF COMPOUND ARMOUR PLATES which Invention has been
communicated to me from abroad by Messrs Marrel Bros of Rive de Gier, Loire
in the Republic of France to be as follows:-
This Invention relates to the manufacture of armour plates composed partly of
hard steel and partly of soft steel cast in one and the same mould.
In the Specification of former Letters Patent granted to
me and dated
December 21st 1882 N° 6113 there is described a method of manufacturing
compound armour plates by the employment of a thin partition of metal dividing
the mould into two compartments for the reception of the two qualities of metal
which when poured into the mould fused the thin partition and became united in
one solid block.
According to the present Invention the partition plate is dispensed with and a
more perfect union or weld of the two qualities of steel is obtained by operating
as hereinafter described.
In carrying out the present Invention that portion of the mould which is to
contain say the hard steel is filled up with a block of metal such as iron or steel,
representing the volume of hard steel in the complete plate-The soft steel is then
poured into the mould at the side of this block and when it has cooled or solidified
sufficiently to enable it to retain its form without support, the said block is removed
and the hard steel is poured into the space which it occupied in the mould-Under
these conditions the metal firstly poured into the mould retains sufficient heat to
enable the two qualities of steel to be perfectly welded and united.
In order to facilitate the removal of the filling block or plate and prevent it from
sticking to the molten metal a thin plate or lining of iron may be interposed
between the filling block and the molten metal-This lining is so thin that it
becomes fused and intimately united with the steel.
The two different qualities of metal may be prepared in separate furnaces or in
one and the same furnace.

page_text: In the latter case the furnace is charged with a sufficient quantity of metal to
complete the plate or ingot and when the metal is in the condition of soft steel the
requisite quantity of soft steel is run into the mould and the tapping hole is then
closed and whilst the soft steel is solidifying and the filling block is being removed
the contents of the furnace are brought to the condition of hard steel which is
poured into the mould at the side of the soft steel previously introduced and with
which it becomes firmly united.
Either the soft or the hard steel may be introduced firstly into the mould and
the metal may be run into the mould direct from the furnace or by the employment
of a casting ladle.

page_text: COMPLETE SPECIFICATION.
I JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of my Invention for "IMPROVEMENTS IN
THE MANUFACTURE OF COMPOUND ARMOUR PLATES "
which Invention has been
communicated to me from abroad by Messrs Marrel Brothers of Rive de Gier Loire
in the Republic of France, and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :-
This Invention relates to the manufacture of armour plates composed of different
qualities of metal (such as hard steel and soft steel) cast in one and the same
mould.
In the Specification to former Letters Patent granted to me and dated
December 21st 1882 N° 6113 there is described a method of manufacturing
compound armour plates by the employment of a thin partition of metal dividing
the mould into two compartments for the reception of the two different qualities
of metal which when poured into the mould fused the thin partition and became
united in one solid block.
According to the present Invention this partition plate is dispensed with and
a more perfect union or weld of the two qualities of steel is obtained by operating
as hereinafter described.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same and for that purpose shall refer to
the several figures on the annexed sheet of drawings the same letters of reference
indicating corresponding parts in all the figures.
Figure 1 of the accompanying Drawings shews the arrangement described in the
Specification to my said former Patent and figures 2 and 3 represent horizontal
sections of the mould employed according to the present invention.
According to the arrangement described in my said former Specification a metal
plate M is interposed between the two qualities of metal cast in the spaces A and B
for the soft and hard steel respectively as illustrated in figure 1 but in carrying
out the present invention a mould G figures 2 and 3 is employed of an internal
capacity equal to the dimensions of the compound ingot to be produced and
supposing that the soft steel is to be cast first that portion of the mould which is
to contain the hard steel is filled up with a block C figure 2 of metal such as iron
or steel representing the volume of hard steel in the complete plate-The soft steel
is then poured into the mould so as to fill the space A¹ at the side of this block
and when it has cooled or solidified sufficiently to enable it to retain its form
without support the said block is removed and the hard steel is poured into the
space which the said block occupied in the mould Under these conditions the
metal firstly poured into the mould at A¹ retains sufficient heat to enable the two
qualities of steel to be perfectly welded and united into one compound plate.
In order to facilitate the removal of the filling block or plate C and prevent it
from sticking to the molten metal a thin plate or lining D (figure 3) of iron may
be interposed between the filling block and the molten metal. This lining is so
thin that it becomes fused and intimately united with the steel.

page_text: The manufacture may be carried on with two furnaces or with one furnace
When operating with two furnaces the metal from each furnace is run into a
separate ladle-The ladle containing the soft steel is first emptied into the mould
and when it has solidified sufficiently the filling block C is removed and hard steel
from another ladle is poured into the space occupied by the said block.
When operating with one furnace only this furnace is charged with a sufficient
quantity of metal to complete the compound ingot and when the metal is in the
condition of soft steel the furnace is tapped. The requisite quantity of soft steel is
run into the mould. The tapping hole is then closed and whilst the soft steel is
solidifying and the filling block is being removed the contents of the furnace are
recarbonized and brought to the condition of hard steel which is poured into the
mould at the side of the soft steel previously introduced and with which it becomes
firmly united.
..
Either the soft or the hard steel may be introduced firstly into the mould and
the metal may be run into the mould in any suitable way such as directly from
the furnace or by the employment of a casting ladle.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
In the manufacture of compound armour plates composed of two different
qualities of metal such as soft and hard steel cast in one ingot, introducing firstly
into the mould a metal block or filling piece and introducing the metal of one
quality into the space at the side of this block or filling piece and then when this
portion of the ingot has attained sufficient consistency removing the metal block
or filling piece from the mould and introducing the metal of the other quality into
the space formerly occupied by the said block or filling piece substantially as
hereinbefore described with reference to Figures 2 and 3 of the accompanying
drawings.