Improvements in the Manufacture of Armour Plates and in Ingots therefor.
Year: 1893

page_text: The decision of the Chief Examiner, acting on behalf of the Comptroller, of the
19th day of March 1895, allowed, under Section 18 of the Patents, &c.
Act, 1883, an Amendment of this Specification.
Date of Application,. 8th Dec., 1893
Complete Specification Left, 29th Aug., 1894-Accepted, 6th Oct., 1894
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Armour Plates and in Ingots
therefor.
I, THOMAS HAMPTON of Millhouses, near Sheffield in the County of York,
Steel Manufacturer, do hereby declare the nature of my invention to be as
follows:-
..
The object of my invention is to manufacture a superior, and more perfectly
constructed armour plate, that is, a plate having a hard face, and a softer back,
and a much softer middle or intermediate part, all being in perfect combination.
This object I attain by casting compound steel ingots, having a "hard" quality
on one surface, a milder" quality on the reverse side of the casting, and the
middle or intermediate part of a "soft" quality; thus possessing ductility and
strength in a high degree, combined with an extremely hard and impenetrable
front, requiring no afterprocess of hardening.
The hard face is intended to break up the projectiles, the "mild" quality to
impart additional resistance to penetration after the "hard" front has performed
its duty, and the "soft" steel is intended to prevent cracks in the rear part of the
plates.
The compound steel ingots are produced in suitable moulds, made to hold a
sufficient quantity of steel to produce an armour plate of any desired dimensions.
The mould is placed in a horizontal position and the "hard"quality of steel is
cast first, leaving a sufficient space in the upper portion of the mould to receive the
"soft" and likewise the "mild" qualities.
"
The "soft" steel is then poured in the form of "spray" or very fine streams
upon the "hard" steel whilst the latter is in a fluid or semi-fluid state, and the
mild steel is afterwards poured in like manner upon the "soft" steel, a perfect
combination of the several qualities being thereby effected. The "mild" quality
may if desirable be poured upon the "hard" steel and the "soft" steel afterwards
upon the "mild" quality.
"
The steel may be manufactured by what is known as the "Bessemer," "Siemens
" "crucible
Martin,"
or other like process, or by a combination of the same.
The "hard" quality should contain 0-70 to 2.00 per cent., and the "soft"
quality 0-10 to 0-25 per cent. of carbon, silicon 0.03 to 0-10 per cent., phosphorus and
sulphur 002 to 0.06 per cent., respectively, and manganese 0-25 to 2.00 per cent.
The hard steel may also contain a small proportion of chromium.

page_text: The "mild" quality should contain 0.25 to 0.75 per cent. of carbon, and 2.00
to 10.00 per cent. of nickel, silicon 0.03 to 0.10 per cent., sulphur and phosphorus 0.02
to 0.06 per cent., respectively, and manganese 0-25 to 100 per cent.
I do not however confine myself to the above named proportions.
Dated the 5th day of December 1893.
ROBT. F. DRURY, C.P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.
Improvements in the Manufacture of Armour Plates and in Ingots
therefor.
I, THOMAS HAMPTON of. Millhouses, near Sheffield in the County of York,
Steel Manufacturer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:―
The object of the invention is the production of a superior compound armour
plate, to those heretofore manufactured, the said plate having a hard face, a soft
back, and a much softer intermediate or central part, the said parts being in perfect
combination, and each retaining their separate qualities.
In order to produce such a compound plate I first cast an ingot combining the
three qualities of steel in layers, namely a hard quality of special composition upon
one surface, a milder quality upon the reverse side, and a still milder quality in the
centre, that is between the two former.
The ingot mould is arranged horizontally so that the several layers of steel
which compose the ingot may flow to a uniform thickness throughout, and I prefer
to cast the hard quality of steel first, then I cast the soft centre layer, and lastly
the mild quality for the back.
In casting the compound ingot I take care to obtain a perfect combination or
junction of the layers of steel without detrimental amalgamation or destruction of
their distinctive qualities.
The steel used may be produced by the processes known as Bessemer, Siemens-
Martin, crucible or other process, or combination of processes.
From experiments and practice I find that the hard quality steel for the face of
the plate should contain carbon which may vary in quality from 0.50 to 2-00
per cent.,
silicon 002 to 0.15 per cent, phosphorus and sulphur not to exceed 0.10 per cent.
respectively, and iranganese 0.25 to 2.0) per cent., with chromium up to 5 per cent.
The soft steel should contain carbon which may vary up to 0-30 per cent., silicon
up to 0.15 per cent., phosphorus and sulphur 0.02 to 0.10 per cent. respectively, and
manganese (.25 to 2:00
per cent.
The mild quality should contain carbon 0-25 up to 0-50 per cent., nickel 0.50
to 5:00 per cent.; silicon 002 to 0.15, sulphur and phosphorus 0-02 to 0-10 per cent.
respectively, and manganese 0.25 to 200 per cen'.
The ingot so composed and cast may then be rolled, forged, pressed, or otherwise
formed into a plate, and after being bored for bolts and otherwise machined, the
finished plate may be subjected to a hardening process if desired.
In some cases the two back layers may be transposed.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed, I declare that I make
no general claim to a compound armour plate cost in two or more su cessice layers of
metals of different qualities, but what I claim is:
1.-Custing a compound ingot for armour plates having a hard face-on-one-side,

page_text: amild steel free-on-the-opposite-side, and a softer-steel centre or intermediate-part,
the whole substantially as herein before described.
Casting-a-compound-ingot-for-armour-plates, consisting of three-layers, one
un-onter-one-of-hard-steel, and the-two others of two different qualities-substantially
as described.
A compound armour plate consisting of three layers of steel cast together in
one mould and in perfect cohesion, having a hard face, a soft back, and a softer
intermediate part, each layer composed substantially as hereinbefore described.
4. A compound-armour-plate, consisting of three-layers-and qualities of steel in
perfect cohesion, the hard layer or face of which contains a proportion of chromium
substantially-as-hereinbefore described.
Dated the 25th day of August 1894.
ROBT. F. DRURY, C.P.A.,
Bank Buildings, George Street, Sheffield, Agent for Applicant.