Improvements in Compound Armour Plates.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvements in Compound Armour Plates.
I, ALFRED LONGSDON, of 9 New Broad Street, in the City of London, Civil
Engineer, do hereby declare the nature of this invention (a communication to me
from abroad by Fritz Asthöwer of Essen in the Empire of Germany Engineer)
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
The manufacture of compound armour plates has hitherto been effected principally
by a welded wrought iron plate being made, upon one side of which, after it has
been previously brought to a bright red heat in a furnace and built into a mould,
hard steel is welded by being poured in a molten condition into the mould in which
the wrought iron plate is. The steel, instead of being welded on to the wrought
iron, is also welded on to a homogeneous iron plate (called flusseisen in German)
cast in a mould, or steel and homogeneous iron are poured at the same time into a
mould, which is separated by a partition-wall, so that the steel and homogeneous
iron are contemporaneously welded with the partition-wall and thus a solid plate is
formed. In some cases compound plates instead of being made in this simple
manner are made in such a way (by one or other of the previously mentioned
processes of manufacture) that the compound plate consists of more than two layers
alternately hard and soft. The object of the employment of the simple compound
plate is that the hard steel which is first struck by the projectile should break the
force of the shot and the soft layer, which is behind same, should prevent the actual
destruction of the plate.
To meet the requirements of the present day the materials which have hitherto
been employed in the manufacture of compound armour plates, do not altogether
suffice, in any case it is desirable to find a more resisting material for the harder
as well as for the softer part of the plate. For this purpose the respective alloys
of steel and homogeneous iron with nickel as well as of wrought iron with nickel,
are specially suitable for both parts, as the nickel alloys of iron, besides having a
greater hardness than the corresponding steel and iron, possess an altogether special
toughness, thus the compound plates may be formed of nickel steel with ordinary
homogeneous iron, or wrought iron or with compounds of nickel with the iron, or
with steel and nickel iron or combined nickel steel and nickel iron in any of the
known methods of manufacture.
By the use of nickel-steel for the front side of a simple compound plate the same
is rendered much less liable to crack, when struck by a projectile and the soft
back consisting of nickel iron, homogeneous or wrought, whilst possessing a much
greater resisting capacity against the further penetration of the projectile, affords
a far higher security against further cracking than a common compound plate which
is obtained for example by welding together single iron and steel plates separately
manufactured or by casting on of single layers to such plates or by casting of the
different layers in a mould with different divisions separated by thin partition walls
as aforesaid.
Of course the use of nickel steel and nickel iron for compound plates is
applicable with all the variations in the manufacture of the simple compound
plates.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1
1. In compound armour plates, composed of two or more layers of materials of
2

page_text: material from nickel iron, wrought iron or homogeneous iron or of one or more
layers of the harder material from nickel-steel or of the formation of single or more
or less hard and soft layers of nickel iron and nickel steel, for the purpose of
increasing the resistance of the armour plates against the penetrating force of the
projectiles and against cracking all substantially as described.
2. In compound armour plates composed of two or more layers of materials of
different degrees of hardness the employment of nickel-steel with homogeneous
iron or with wrought iron, or with compounds of nickel with the iron, or steel
and nickel-iron or nickel steel and nickel iron all substantially as set forth.
Dated this 8th day of June 1891.
ALFRED LONGSDON.
By Brewer & Son,
33, Chancery Lane, London, Agents.
ALFRED LONGSDON.
By Brewer & Son,
33, Chancery Lane, London, Agents.