IMPROVEMENTS IN THE CONSTRUCTION AND MANUFACTURE OF ARMOUR PLATES
Year: 1874

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 CONSTRUCTION AND MANUFACTURE OF ARMOUR
PLATES." A communication from abroad by La Société Marrel,
Brothers, of Rive de Gier, in the Republic of France.
Sealed the 28th July 1874, and dated the 21st February 1874.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 21st February 1874.
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 CONSTRUCTION AND MANUFACTURE OF
ARMOUR PLATES," a communication to me from abroad by La Société
Marrel, Brothers, of Rive de Gier, in the Republic of France, to be as
follows:-
-
This Invention relates to an improved mode of construction and
manufacturing armour plates for protecting ships, forts, batteries, and
for other like purposes, whereby considerable strength and invulnerability

page_text: are imparted to the interior of the plates, whilst at the same time the
malleability and tenacity of their external surface are preserved, and
increased facility is afforded for welding, and consists in forming such
plates of bars composed of a centre or core of steel, cast metal, or other
suitable hard metal or alloy, surrounded by a sheath or casing of
wrought iron or other suitable malleable metal. The bars are rolled to
a rectangular, trapezoidal, or other suitable form, and combined together
by welding so as to form a pile or mass of the required dimensions,
which pile or mass may be employed either alone or with the addition
of a further layer of wrought iron on its top and bottom surfaces. The
bars may be provided with suitable projections and recesses to admit of
their interlocking when placed in juxtaposition.
In lieu of combining a number of bars together a single bar may be
employed rolled to the required dimensions and made in the manner
hercin-before described. Or tho plates may be composed of a thick
plate of steel or cast metal placed between two wrought-iron plates so as
to increase the resisting strength of the centre whilst preserving the
mallcability of the external portions.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Scal Patent 2
Office on the 21st August 1874.
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.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her :
Letters Patent, bearing date the Twenty-first day of February, in the
year of our Lord One thousand eight hundred and seventy-four, in the
thirty-seventh 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, adminis-
trators, 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

page_text: and Ireland, the Channel Islands, and Isle of Man, an Invention for
“IMPROVEMENTS IN THE CONSTRUCTION AND MANUFACTURE OF ARMOUR PLATES," a
communication to me from abroad by La Société Marrel, Brothers, of
Rive de Gier, in the Republic of France, upon the condition (amongst
others) that I, the said John Henry Johnson, my executors or admini-
strators, 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 immediately 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 accom-
panying Drawings and to the letters and figures marked thereon, that is
to say :-
The said Invention relates to an improved mode of constructing and
manufacturing armour plates composed of metals of different hardness
and tenacity for protecting ships, forts, and batteries, and for other
like purposes, whereby considerable strength and invulnerability are
imparted to the interior of the plates, whilst at the same time preserving
the malleability and tenacity of their external surfaces and affording
increased facility for welding.
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..
In the manufacture of armour plates according to this Invention
special bars of great strength are employed, such bars being composed
either of wrought iron and steel or of wrought iron and cast metal, the
wrought iron forming the external portion a, and the steel or cast
metal the central or internal portion 6 of each bar. These bars are
rolled to one of the sectional forms shewn in Figures 1, 2, and 3, or to
any other shape suitable for the purpose.
In order to form the plates the bars so made may be arranged in piles
in a variety of ways, as shewn in Figures 4, 5, 6, 7, 8, and 9, that is to

page_text: say, the plates may be either formed entirely of these compound bars, as
shewn in Figures 4, 6, and 8, or be provided on their two opposite faces
with a thick wrought iron covering, as shewn in Figures 5, 7, and 9.
The compound armour plates may also be made by simply forming the
piles which are to constitute the plates in the manner shewn in
Figure 10, that is to say, by entirely filling the central portion with cast
metal or steel and surrounding it with wrought iron on all sides.
In all cases and whatever may be the method of forming the piles of
which the plates are composed, the welding of their various parts is
always perfect, and the combination possesses great strength and
stability as well as resistance to penetration by reason of the nature of
the materials employed in their composition.
If desired in lieu of the preceding arrangements a thick plate of steel
or cast metal may be employed interposed between two wrought-iron
plates, by which means the strength of the central portion will be 1
increased whilst retaining the malleability of the external faces.
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, forming
armour plates of piles consisting of compound bars composed of wrought
iron and steel or wrought iron and cast metal rolled in such a manner
that the hard metal which provides the necessary resistance to
penetration is completely enclosed in a casing of wrought iron whereby
the welding of the parts is facilitated and the requisite malleability and
tenacity of the external surfaces are ensured, substantially as herein-
before described and illustrated by the accompanying Drawings.
In witness whereof, I, the said John Henry Johnson, have to this
my Specification set my hand and seal, this Twenty-first day of
August One thousand eight hundred and seventy-four.