IMPROVEMENTS IN ARMOUR PLATES, AND IN THE METHOD OF PRODUCING THE SAME
Year: 1876

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
ARMOUR PLATES, AND IN THE METHOD OF PRODUCING THE SAME."
A com-
munication from abroad by the Firm of Marrel, Brothers, of Rive-de-Gier
(Loire) in the Republic of France. Ironmasters.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at the
Office of the Commissioners of Patents on the 8th December 1876.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN ARMOUR PLATES, AND IN THE METHOD OF
PRODUCING THE SAME." A communication from abroad by the Firm of Marrel,
Brothers, of Rive-de-Gier (Loire), in the Republic of France, Ironmasters.
•
This Invention consists in the construction of wrought-iron armour plates with
welded steel webs or ribs, whereby the defects inherent to armour plates as ordinarily
constructed are obviated.
Armour plates made of wrought iron, as they are at present manufactured, do not
offer the necessary resistance to arrest the motion of projectiles discharged from
guns of large calibre, whilst on the other hand steel plates break with the blow of
the projectile. By means of this Invention however the difficulty of constructing
plates presenting great resistance to penetration, and not liable to break, is overcome
by utilizing the resisting capacity of steel, whilst at the same time preserving the
advantages resulting from the ductility or toughness of iron.
In carrying out this Invention the armour plates are constructed of iron, with
steel webs or ribs, and they may be manufactured in a variety of ways whilst still
retaining the same principle. For example, the surface of the plate to which the
steel webs or ribs are attached may be flat, the steel portion forming itself a webbed
or ribbed plate, or the iron plate inay be provided with grooves or recesses for the
reception of the steel portion. The longitudinal steel webs or ribs may also be
connected by transverse webs or ribs of smaller section, thus forming a cellular
plate.
In all cases a rupture of the plate protected in this manner with steel webs or
ribs can only take place in a longitudinal direction, which is much less serious than
the rupture in a transverse direction, which frequently occurs in ordinary plates.
[Price Gl

page_text: The spaces between the steel webs or ribs may be filled up wholly or partially
.with iron adhering or otherwise, if desired.
It is preferred to manufacture these plates in the following manner: A mould is
employed, which is constructed in two parts, united by a steel or iron band carrying
journals or trunnions. Into this mould the iron plate, heated to a white heat and
sprinkled with borax, is introduced, and the mould is then turned upon its two
journals or trunnions, so as to bring it into a vertical position, after which steel to
form the webbed or ribbed portion is run in, which steel coming while in a molten
condition into contact with the heated plate becomes united thereto. The compound
plate thus constructed is removed from the mould, and placed in a reheating furnace
in order to be further treated by rolling or forging.
Spaces or recesses are formed in the mould to admit of the introduction of the
fork for removing the plate to the reheating furnace, and which also serves to place
the wrought-iron plate in the mould when the latter is in a horizontal position.
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 4th
June 1877.
JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
Gentleman. "IMPROVEMENTS IN ARMOUR PLATES, AND IN THE METHOD OF PRO-
DUCING THE SAME." A communication from abroad by the Firm of Marrel, Brothers,
of Rive-de-Gier (Loire), in the Republic of France, Ironmasters.
The said Invention consists in the construction of wrought-iron armour plates,
with welded steel webs or ribs, whereby the defects inherent to armour plates as
ordinarily constructed are obviated.
Armour plates composed of wrought iron, as they are at present manufactured,
do not offer the necessary resistance to arrest the motion of projectiles discharged
from guns of large calibre, whilst on the other hand steel plates break under the
blows of the projectile. By means of the said Invention however the difficulty of
constructing plates presenting great, resistance to penetration, and not liable to
break, is overcome by utilizing the resisting capacity of steel, whilst at the same
time preserving the advantages resulting from the ductility or toughness of iron.
Iron armour plates constructed according to the said Invention, with steel webs
or ribs, may be manufactured in a variety of ways whilst still retaining the same
principle, examples of which are shewn in the accompanying Sheet of Drawings,
which I shall now proceed to describe.
Figures 1, 2, 3, 4, 5, 6, 7, and 8 of the Drawings illustrate various modes of con-
structing plates according to the said Invention; and Figures 9 and 10 represent
the mould used for the production of the plates with a plate in course of manu-
facture.
According to the arrangements illustrated in transverse section and elevation in
Figures 1 and 2 respectively, and in transverse section in Figure 3, the surface of
the iron plate a, to which the steel webs or ribs b are attached, is flat, whilst in the
arrangements shewn in transverse section and elevation in Figures 4 and 5 respec-
tively, and in transverse section in Figure 6, the iron plate a is provided at b¹ with
grooves or recesses for the reception of the steel portion b.
In the arrangement shewn in section and elevation in Figures 7 and 8 respectively
the longitudinal steel webs or ribs bare connected by transverse webs or ribs b² of
smaller section, thus forming a cellular plate.
In all cases a rupture of the plate protected in this manner with steel webs or
ribs can only take place in a longitudinal direction, and a longitudinal rupture is
much less serious than the rupture in a transverse direction, which frequently occurs
in ordinary plates.

page_text: The spaces between the steel webs or ribs may be filled up wholly or partially
with iron, adhering or otherwise, if desired.
It is obvious that the number, forms, and dimensions of the steel channels in the
plates constructed according to the said Invention may be varied as found
desirable.
Figures 9 and 10 illustrate the mode of manufacturing armour plates according
to the said Invention; Figure 9 being a plan of an ingot mould, with a plate con-
tained therein, and Figure 10 an elevation of the mould. A is the mould, which
is made in two parts A, A, united by a steel or iron band B provided with journals
or trunnions C, into which mould the iron plate a heated to a white heat and
sprinkled with borax is introduced. When the plate a is in position the ingot
mould is turned upon its two journals or trunnions C, so as to bring it into &
vertical position, as shewn, after which steel to form the webbed or ribbed portion b
is run in, which steel coming whilst in a molten condition into contact with the
heated plate becomes united thereto. The compound plate thus constructed is
removed from the mould, and placed in a reheating furnace in order to be further
treated by rolling or forging.
The hollow spaces or recesses E, Figure 9, formed in the mould, are provided to
admit of the introduction of the fork for removing the plate to the reheating
furnace, and which also serves to place the wrought-iron plate a in the mould when
the latter is in a horizontal position.
Having now described and particularly ascertained the nature of the said Inven
tion, 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, the construction of wrought-iron armour plates with steel webs or
ribs, and the method of producing the same, substantially as herein-before described
and illustrated by the accompanying Drawings.
In witness whereof, I, the said John Henry Johnson, have to this my Specifi-
cation set my hand and seal, this Thirty-first day of May, One thousand
eight hundred and seventy-seven.
J. HENRY JOHNSON. (L.S.)