Improvements in the Manufacture of Armour Plates, and in Apparatus therefor.
Year: 1895

page_text: PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Armour Plates, and in
Apparatus therefor.
We, ALEXANDER WILSON, Steel Manufacturer, and FREDERIC STUBBS,
Steel Works Manager, both of the Cyclops Steel and Iron Works, Sheffield, in
the County of York, do hereby declare the nature of this invention to be as
follows:-
Armour plates are now commonly made with the front face hardened but the
process of hardening the face has the disadvantage of also to some
hardening the back.
The object of this invention is to remedy this defect.
extent
This is done by placing the plate after it has had its face hardened in any
ordinary way in a furnace in such manner that whilst the back is exposed to
the heat and is thus annealed the face is kept coul and therefore retains its
hardness.
For this purpose a chamber is formed on one side generally the bottom of the
furnace there being an opening between the two of such a size that it is closed
by the armour plate. In the chamber there are cooling appliances such as water
jets or for flat plates a tank of water into which the hard face dips may be
employed.
Dated this 25th day of October 1895.
ALEX. WILSON.
FRED. STUBBS.
Improvements in the Manufacture of Armour Plates, and in
Apparatus therefor.
We, ALEXANDER WILSON, Steel Manufacturer, and FREDERIC STUBBS,
Steel Works Manager, both of the Cyclops Steel and Iron Works, Sheffield, in
the County of York, 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 :—
An mour plates are now commonly made with the face hardened, but the process
of ha ening the face has the disadvantage of also to some extent hardening the
back.
The object of this invention is to remedy this defect.
This is done by placing the plate after it has had its face hardened in any
ordinary way in a furnace, in such a manner that whilst the back is exposed to
the heat thereof and is then annealed, the face is kept cool and therefore retains
its hardness.
For this purpose a chamber is formed on one side, generally the bottom, of the
furnace; and another chamber immediately under the roof of the furnace, there

page_text: being an opening between the two of such a size that it is closed with the armour
plate. In the lower chamber there are cooling appliances such as water jets,
or for flat plates a tank of water, into which the hard face dips, may be
employed.
There are various ways of forming the heating chamber and also that in which
the cooling apparatus is placed; but, in order that our invention and the means
of carrying out may be fully understood, we shall now proceed to describe one
method of doing the same and for that purpose shall refer to figures on the
accompanying sheets of drawings, the same letters of reference indicating corre-
sponding parts in all the figures.
Figure 1 is a longitudinal vertical section of the furnace that we prefer to use
for this purpose,
Figure 2 is a transverse vertical section and Figure 3 a sectional plan with the
roof removed.
In these figures an armour plate is shown in position ready to undergo the
process of our invention.
The armour plate A, is placed with its hard face downwards, on a travelling
carriage or bogie B, and is supported at a convenient height above the body of
the bogie on the edges of plates C, which are formed to fit the curved or
straight face of the plate; supported on the body of the bogie and between it
and the face of the armour plate is an iron water tank D, in this latter is fixed a
"water-grid" E formed by a series of pipes, in the cross pipes of this grid are
screwed a number of jet pipes E' for the purpose of directing the streams of water
against the face of the plate to prevent its being heated and to keep it cool
during the time that the back of the armour plate, which is now uppermost, is
being annealed by the action of the flame and heat passing over it. Such heat
and flame being derived from the fire on the grates F of the furnace.
On the sides and ends of the bogie is a frame G attached thereto which carries an
overhanging shelf H for the purpose of supporting a dividing floor I made of any
refractory material, such as firebrick or ganister, this floor is carried around and
along the four edges of the armour plate, but leaving about the upper half of all
the edges exposed to the action of the annealing heat; and in order to allow
for the expansion of the plate when its upper side is hot, this floor is so arranged
that although it firmly embedded against the edges of the armour plate it does
not touch the side walls and front end of the furnace, the small space M caused
thereby is covered by loose slabs N of firebrick, it will therefore be seen
that by means of the armour plate and the surrounding floor, a horizontal division
is made in the furnace, the upper portion being the one in which the back of the
armour plate is heated and the lower portion being that in which the face of the
armour plate is kept cool.
This division prevents the products of combustion passing from the upper
chamber into the lower and it also prevents the cooling medium passing from the
lower chamber into any portion of the upper one.
It will also be seen that the whole of the divisional structure can be built up on
the travelling carriage or bogie, at any convenient place which can afterwards be
drawn and withdrawn into and out of the furnace at will.
Doors are formed at the open end of the furnace and when open will admit
of the bogie travelling into it and when closed will prevent the products of cm-
bustion from passing out of the furnace otherwise than by the dampered chimney P
arranged for that purpose.
The iron tank D which is fixed on the bogie is required for the purpose of
catching the water after it has been impelled from the jets of the "grid" against
the face of the armour plate, it can also be used for keeping cool the face of a flat
armour plate without the use of the "grid" water is conveyed to and from the
grid and tank by means of pipes Q and R which can be connected and
disconnected at pleasure.
66
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It is well known to steel makers and others that the heating of a bar or plate of

page_text: hard steel to a dull red heat or thereabouts and afterwards allowing it to cool
very slowly and gradually will cause such bar or plate to become very much
softer, and although its tensile strength is reduced its ductility is correspondingly
increased.
It will now be seen and readily understood that by the means we employ we can
heat the back of an armour plate to any desired temperature say from 1000° to
1400° Fah. and can also keep the face of the plate cool during the whole time it is
necessary to carry out our annealing process and do the same for the purpose
intended. The time occupied being about sixty hours for a plate 9" in thickness
and correspondingly more or less with other plates in accordance with their
respective thicknesses.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The process of treating armour plates consisting in first hardening the face
and then annealing or softening the back by exposing it to heat whilst the face is
kept cool.
2. The process of treating armour plates consisting in first hardening the face
and then annealing or softening the back by exposing it to heat whilst the face is
kept cool by jets of water.
3. The process of treating armour plates consisting in first hardening the face
and then annealing or softening the back by exposing it to heat whilst the face is
kept cool by dipping into water.
4. The process of treating armour plates substantially as described.
5. Apparatus substantially as described and shown in the drawings.
ALEX. WILSON.
FRED STUBBS.