Year: 1886

page_text: Date of Application, 18th Nov., 1886.
Complete Left, 29th July, 1887.
Complete Accepted, 9th Sept., 1887.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of this Invention to be as follows:-
This invention relates to a process and apparatus for hardening hollow articles
of steel, such as explosive shells, whereby the cooling of the interior or a portion
of the interior is ensured before hardening the exterior.
In hardening hollow steel castings by the ordinary means, the exterior cannot
contract sufficiently while the interior portions of the metal are still hot and expanded
and at a later stage when the interior in turn tends to contract on cooling, it is
prevented from doing so in consequence of the external layer having become hard
and cold, whereby strains are set up in the metal which frequently cause flaws.
For large steel castings it is therefore desirable to be able to cool the interior
or a portion thereof before hardening the exterior.
In order to effect this internal cooling, whilst the exterior is kept hot, the shell
or other hollow article of steel is placed, either in a furnace or metallic saline or other
bath at a red heat, with its base or open end upwards and its point or face downwards,
so that the interior is readily accessible.
When the shell or article has attained the hardening temperature, the cooling
of its interior is effected without removing it therefrom, in the following manner.
Reference being had to the accompanying drawing. Into the shell is introduced
the leg A of a siphon, terminating in an annular head or ring packing, making
a tight joint against the sides of the cavity of the shell, so as to enclose a chamber o

page_text: through which water under pressure is kept flowing, the water entering by the small
pipe a, and flowing out by A and B. By varying the diameter of the ring packing,
the size of the chamber o, and the extent of surface exposed to the action of the water
may be increased or reduced.
When the interior is sufficiently cooled the siphon is first completely discharged
of its contents in order to avoid the water completely filling the cavity of the
shell or other article, after which it may be withdrawn.
The siphon may be emptied either by means of steam or gas under pressure
whereby the water is expelled, or by applying the water under pressure to act as the
inducing jet in the cone of an ejector as in the drawing.
The packing ring may be detachable and be left in the shell or other article should
it have become fixed therein by the contraction of the metal.
The shell or other article can then be removed from the bath, and the hardening be
proceeded with.
Dated thin 10th des SNL
1000
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: COMPLETE SPECIFICATION.
A Process and Apparatus for Hardening Shells and other Hollow
Articles of Steel.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of this Invention (a communication to me from
abroad by Henri Aimé Brustlein, of Firminy, (Loire) France, Engineer and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
This invention relates to a process and apparatus for hardening hollow articles of
steel, such as explosive shells, whereby the cooling of the interior or a portion of the
interior is effected before the hardening of the exterior.
In hardening hollow steel castings by the ordinary means, the exterior cannot
contract sufficiently while the interior portions of the metal are still hot and expanded,
and at a later stage when the interior in turn tends to contract on cooling, it is
prevented from doing so in consequence of the external layer having become hard and
cold, whereby strains are set up in the metal which frequently cause flaws.
For large steel castings it is therefore desirable to be able to cool the interior.
or a portion thereof before hardening the exterior.
In order to effect this internal cooling, whilst the exterior is kept hot, the shell or
other hollow article of steel is placed, either in a furnace or in a metallic saline
or other bath at a red heat, with its base or open end upwards and its point or face
downwards, so that the interior is readily accessible.
When the shell or article has attained the hardening temperature, the cooling of its
interior is effected without removing it from the furnace or bath, in the following
manner, reference being had to the drawing which accompanied my provisional
specification.
Into the shell is introduced the leg A. of a siphon, terminating in an annular head
or ring packing, making a tight joint against the sides of the cavity of the shell,
so as to enclose a chamber o through which water under pressure is kept flowing, the
water entering by the small pipe a and flowing out by A and B. By varying
the diameter of the ring packing, the size of the chamber o, and the extent of
the surface exposed to the action of the water may be increased or reduced.
When the interior is sufficiently cooled the siphon first completely discharged
of its contents in order to avoid the water completely filling the cavity of the shell or
other article, after which it may be withdrawn.
The siphon may be emptied either by means of steam or gas under pressure whereby
the water is expelled, or by applying the water under pressure to act as the inducing
jet in the cone of an ejector as shown at G in the drawing.

page_text: The packing ring may be detachable and be left in the shell or other article should
it have become fixed therein by the contraction of the metal. The shell or other
article can then be removed from the bath, and the external hardening be proceeded
with.
The invention is not limited to the exact arrangement described which may
be varied in practice as occasion may require.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed, I declare that what I claim is :-
1. The herein described method of hardening hollow articles of steel, which consists
in cooling the interior or a portion thereof while placed base uppermost and
point downwards in a heating furnace or bath, before cooling the exterior, substan-
tially as and for the purpose specified.
2. The herein described means for effecting the colling of the interior of hollow
articles of steel, while placed in the heating furnace or bath, before hardening
their exterior, said means consisting in the combination of a siphon tube A provided
with an annular head or ring packing fitting the interior of the article and enclosing
a chamber o therein; a pipe a passing through the siphon leg A for the supply of the
cooling liquid under pressure, and an ejector G or equivalent means for emptying the
siphon A before removing the article from the furnace, substantially as described and
illustrated in the drawing.
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.