Improvements in the Manufacture of Armour Plates and other similar articles.
Year: 1890

page_text: Date of Application, 22nd Dec., 1890
Complete Specification Left, 21st Sept., 1891-Accepted, 24th Oct., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Armour Plates and other
similar articles.
I, JOSEPH ELTON BOTT, of Eyam in the County of Derby, Metallurgist,
do hereby declare the nature of this invention to be as follows:-
The invention has for its object the manufacture of armour plates and other
similar articles of comparatively soft metal on the back and of gradually increasing
hardness throughout the thickness thereof until the maximum degree of hardness is
obtained on the face.
For this purpose I employ a layer of gun metal or of other suitable tough and
comparatively soft metal or alloy for the back and I cast thereon, in succession,
layers of metal or alloy of gradually increasing hardness employing a layer of hard
steel or alloy for the face; after each layer is cast I submit it when partially cooled
but still at a welding heat to considerable pressure through the agency of carbonic
acid gas, steam, air, or other elastic medium capable of exerting pressure whereby
I not only condense each layer but effect the more intimate union thereof with the
lower layer and when employing carbonic acid gas avoid oxidation of the surface.
For the purpose of carrying this process into effect I first cast a layer of gun
metal in a mould contained in a casting box having a detachable bottom, body and
top the pouring hole or ingate of which, may be formed towards one side of the top
and body and the molten metal is delivered into the mould preferably at or near
the bottom thereof; .when the metal has somewhat cooled but before it has com-
pletely set I remove the cover or top which can be readily done as the piece of
metal in the pouring hole or ingate can then be easily broken. After the removal
of the cover or top of the casting box I apply a strong covering plate which rests
on the body of the casting box and is constructed so as to form an enclosed space
above the metal in the mould.
This covering plate is clamped firmly to the body of the mould and to the centre
thereof is attached a tube which is connected to a pump or receiver capable of
supplying carbonic acid gas, steam, air &c. under pressure to the space above the
metal in the mould. By this means the metal is submitted to a considerable
pressure which consolidates the same and effects its intimate union with the lower
layer of metal. When the necessary pressure has been applied I remove the
covering plate and apply another casting box or body with its cover on the top of
the one already used, making use of the already cast metal as a base for the new
mould thus prepared I then pour metal into the new mould and proceed to apply
pressure thereto as before described repeating the operations as often as is required
to complete the plate, finally finishing with the hard external layer of metal the
whole being capable of resisting the excessively hard projectiles in modern use.
Dated December 22nd 1890.

page_text: Figure represents a vertical cross section of the casting box employed for
casting the lowermost layer or back of an armour or other like plate.
Figure 2 represents a vertical cross section of a compound casting box showing
the arrangement of the various casting boxes employed in the manufacture of a
complete compound-armour or other-like-plate,-and-
Figure 3 is a plan of part of the same.
In carrying this process into effect 1. first cast a layer a of gun metal, or of other
suitable tough and comparatively soft metal or alloy, in a mould contained in a
casting box having a detachable bottom A, body A, and top A2, the pouring hole
or ingate A³ of which may be formed towards one side of the top A² and body A',
and the molten metal is delivered into the mould preferably at or near the bottom
thereof, as shown; when the metal or alloy forming the back a of the plate has
somewhat cooled, but before it has completely set, I remove the cover or top A²,
which can be readily done as the piece of metal in the pouring hole or ingate A³ can
then be easily broken. After the removal of the cover or top A2 of the casting
box, I apply a strong covering plate, which may be of somewhat similar form to that
-of-the-cover-Abut without its lining, and which rests on the body A¹ of the casting
box in a similar way and is constructed so as to form an enclosed space above the
metal in the mould.
This covering plate is clamped firmly to the body A¹ of the mould, in a similar
manner to the top or cover A, which may be by means of screw rods A hinged to
the bottom A. and nuts A' screwed on such rods A' and pressing against forked
lugs A fixed to the top or cover A². To the covering plate is attached a tube A',
shown by dotted lines, which is connected to a pump or receiver capable of
supplying carbonic acid gas, steam, air, etc., under pressure, to the space above the
metal in the mould. By this means the layer a of metal or alloy is submitted to a
considerable pressure, which consolidates the same and, when more than one layer
has been cast, effects the intimate union of the last poured layer with the layer of

page_text: metal or alloy next below. When the necessary pressure has been applied and the
metal set, I remove the covering plate and apply another casting box or body A¹
with its cover A2 on the top of the one already used, making use of the already cast
metal or alloy a as a base for the new mould thus prepared; I then pour metal or
alloy into the new mould and proceed to apply pressure thereto as before described,
repeating the operations as often as is required to complete the plate, which latter,
in Figure 2, is represented as composed of four layers 1, b, c, d of metal or alloy of
varying degrees of hardness, finally finishing with the hard external layer of metal,
the whole being capable of resisting the excessively hard projectiles in modern use.
The various casting box bodies are formed at their upper and lower edges to fit
together so as to form a tight joint.
I would here remark that the accompanying drawings are mere diagrams
representing one method of carrying my invention into effect, and that the various
parts may be differently formed without departing from the peculiar character of
my invention.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is :-
The manufacture of armour plates and other like articles of layers of metal or
alloy cast, in succession, in moulds and submitted, successively, to the pressure of
gas or other elastic medium, substantially as herein shown and described and for the
purpose stated.
Dated this 21st day of September 1891.
J. ELTON BOTT.
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.