Improvements in the Manufacture of Compound Steel Ingots and other Articles.
Year: 1893

page_text: Date of Application, 26th Jan., 1893
Complete Specification Left, 26th Oct., 1893-Accepted, 2nd Dec., 1893
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Compound Steel Ingots and
other Articles.
We, SAMUEL CHATWOOD, of 76 Newgate Street, in the City of London,
Bankers Engineer, and SAMUEL RAWSTHRONE CHATWOOD, of The Lancashire
Safe and Lock Works, Bolton, Lancashire, Manager, do hereby declare the nature
of this invention to be as follows:-
Our invention consists in an improved mode of preparing ingots of compound
steel to be afterwards forged or rolled into suitable forms for parts of safes armour
or other articles in which security against cutting or penetration by impact is
important and in an improved method of making compound steel castings parts of
which are required to be hard and part soft.
By our Letters Patent No. 5322 of 1882 we provide for the manufacture of
ingots for our compound steel having high carbon steel imbedded within low
carbon steel. The first part of our present invention relates to an improvement
upon the mode of making our compound ingots therein set forth and is as
follows.
We make an ingot of low carbon steel with a number of cellular cavities one
plan of providing which may be by having on the cover of the ingot mould bar
Like projections of suitable form passing to the bottom of the mould these bar like
projections should be slightly tapered to facilitate withdrawing after the low
carbon steel shall have become sufficiently set in cooling to enable the cells to
maintain their form.
As soon as the ingot has become sufficiently plastic to stand without running the
ingot cover with its bar like projections is removed leaving the cells in the ingot.
We then place another cover on the ingot mould with runners in place of the bar
like projections. We prefer to have this cover with a slight recess on its upper
side to serve as a basin to feed the runners and through the runners we fill the
cavities of the ingot with high carbon steel or with suitable steel alloys which
will give a high-resistance to cutting instruments or to penetration by impact.
.. The operation may be reversed the high carbon or steel alloys may form the
body of the ingot and the low carbon the filling of the cells-we prefer however
the former.
This plan of making compound ingots is applicable to other combinations of
metals as for instance combinations of steel and iron or low carbon steel and iron.
Whenever the cellular ingot is allowed to cool it may be reheated by being placed
over a gas burner the flame of which passing through the cellular apertures of the
ingot will raise their sides to a sufficiently high temperature to ensure cohesion
between the sides of the cells and the steel which is poured into them.
Instead of forming the chambers for the high carbon steel in the ingots by
having projections on the moveable sides of the ingot mould as last described we
sometimes place in the ingot mould suitable tubes of wrought iron or steel to
receive the high carbon steel and we place a moveable cover on the ingot mould
in which cover we prepare holes corresponding to the tubes within the ingot mould
which holes serve as runners for filling the tubes with the high carbon steel this
may be done simultaneously with the filling of the ingot mould with low carbon
steel in such manner that the height of the low carbon steel surrounding the tubes
shall correspond with the height of the high carbon steel within the tube.
sometimes heat the tubes in the ingot mould by burning gas within the mould so as
to ensure the fusion of the tubes by the fluid steel and so secure cohesion between
We

page_text: the two qualities of steel. The tubes may be of any convenient dimension and
form.
The second part of our invention relates to compound steel castings which are
not intended to be forged but parts of which require to be machined. The part
requiring to be machined we cast of low carbon steel as for instance the front
portion of safe coffers and parts of the doors of safes and when such parts are
sufficiently set to be no longer fluid we pour into the mould high carbon steel or
suitable steel alloys which are difficult to cut.
When necessary we remove parts of the mould after the setting of the low
carbon steel and substitute other portions providing space for the high carbon
steel which will unite with the low carbon steel first poured into the mould and
form a solid casting.
Dated this 26th day of January 1893
CARPMAEL & Co.,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Compound Steel Ingots and
other Articles.
We, SAMUEL CHATWOOD, of 76 Newgate Street, in the City of London,
Bankers Engineer, and SAMUEL RAWSTHRONE CHATWOOD, of The Lancashire
Safe and Lock Works, Bolton, Lancashire, Manager, 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 :-
Our invention consists in an improved mode of preparing ingots of compound
steel to be afterwards forged or rolled into suitable forms for parts of safes, armour
or other articles in which security against cutting or penetration by impact is
important and in an improved method of making compound steel. castings parts of
which are required to be hard and part soft.
By our Letters Patent No. 5322 of 1882 we provide for the manufacture of
ingots for our compound steel having high carbon steel imbedded within low carbon
steel. The first part of our present invention relates to an improvement upon the
mode of making our compound ingots therein set forth and is as follows.
We make an ingot of low carbon steel with a number of cellular cavities one
plan of providing which may be by having on the cover of the ingot mould bar
like projections of suitable form passing to the bottom of the mould these bar like
projections should be slightly tapered to facilitate withdrawing after the low carbon
steel shall have become sufficiently set in cooling to enable the cells to maintain
their form.
As soon as the ingot has become sufficiently plastic to stand without running the
ingot cover with its bar like projections is removed leaving the cells in the ingot.
We then place another cover on the ingot mould with runners in place of the bar
like projections. We prefer to have this cover with a slight recess on its upper-
side to serve as a basin to feed the runners and through the runners we fill the
cavities of the ingot with high carbon steel or with suitable steel alloys which will
give a high resistance to cutting instruments or to penetration by impact.
The operation may be reversed the high carbon or steel alloys may form the
body of the ingot and the low carbon the filling of the cells-we prefer however
the former.
This plan of making compound ingots is applicable to other combinations of
metals as for instance combinations of steel and iron or low carbon steel and iron.
Figure 1 of the annexed drawings shows a vertical section and. Figure 2 a plan
of a mould prepared for casting a compound ingot in accordance with our invention.
a is a metal ingot mould of the ordinary sort. b is a metal cover placed upon it.
On the underside of the cover 6 are a series of cores or projections consisting of

page_text: bolts 66 clothed with refractory material 63 and faced in the manner usual in
making cores for casting. The upper part of the cover is of trough like form and
t is rammed full of casting sand in which runners and air passages are moulded.
The mould is poured full of low carbon steel, and immediately the metal is set the
cover 6 with the cores upon it, is removed and the runners are broken off.
Figures 3 and 4 show the next stage of the operation; the cover c is put on the
mould and in this cover, as will be seen, runners are moulded to correspond with
the cavities left by the cores previously removed.
High carbon steel is now poured in and all the cavities are filled. The solid
compound ingot thus obtained is rolled and worked in the usual way. As the
metal, to whatever form it may be brought, will contain hard streaks, it will be
very well suited for making safes and strong rooms where resistance to drills and
cutting tools is requisite.
Figures 5, 6, 7 and 8 show a modification; here the mould is produced by
ramming sand about a pattern contained in a mould box; then the pattern is
withdrawn and the cover b with cores or projections as in Figure 1 is put on.
Mild steel is then poured into the mould by the passages d d. Immediately the
metal sets, the cover 6 is removed, the cover c is put on and the high steel is poured
into the cavities of the ingot previously cast.
In some cases it may not be convenient to pour the high steel immediately after
the mild steel has been poured. Whenever the cellular ingot is allowed to cool it
may be reheated by being placed over a gas burner the flame of which passing
through the cellular apertures of the ingot will raise their sides to a sufficiently
high temperature to ensure cohesion between the sides of the cells and the steel
which is poured into them.
is a
In Figure 9 e represents the cellular ingot, it is seen in vertical section.
flue passage in which are ignited gases. 9 is a moveable chimney with which the
ingot is surmounted. The flames passing up through the channels in the ingot,
rapidly raise the temperature of their walls to a high degree; the ingot is then
lifted, placed on a suitable foundation and high steel is poured in to fill the
cavities.
Instead of forming the chambers for the high carbon steel in the ingots by
having projections on the moveable sides of the ingot mould we sometimes place in
the ingot mould suitable tubes of wrought iron or steel to receive the high carbon
steel and we place a moveable cover on the ingot mould in which cover we prepare
holes corresponding to the tubes within the ingot mould which holes serve as
runners for filling the tubes with the high carbon steel this may be done
simultaneously with the filling of the ingot mould with low carbon steel in such
manner that the height of the low carbon steel surrounding the tubes shall
correspond with the height of the high carbon steel within the tube.
This method of producing compound ingots is illustrated by the Figures 10, 11
and 12.
Figure 10 is a vertical section of the parts arranged ready for casting.
is the ingot mould. ii iron tubes set up within it. k a cover prepared as
already described for pouring the high steel. ¹¹ are the passages for pouring in
the mild steel. The cover k is represented in section by Figure 11 and the mould
without the cover is shown by Figure 12.
We sometimes heat the tubes in the ingot mould by burning gas within the
mould so as to ensure the fusion of the tubes by the fluid steel and so secure
cohesion between the two qualities of steel. The tubes may be of any convenient
dimension and form.
Sometimes we fill the ingot mould around the tubes with sand instead of low
carbon steel so that the tube with its filling of high carbon steel may be removed
and be rolled into a compound steel bar of suitable section say for example to form
the frame of a safe body or the frame of the door of a safe or for the bolts of a
safe or for rivets or screws requiring a soft exterior and a hard interior.
The tubes may be of any convenient form according to the section into which

page_text: the compound steel is required to be rolled and may be of cast steel or of wrought
iron as may be most convenient. If found desirable for some purposes where hard
exteriors and soft interiors are required the tubes may be of high carbon steel and
be filled with low carbon steel but for most purposes we prefer that our bars
should be formed by rolling out of ingots made of low carbon or wrought iron
tubes filled when heated with high carbon steel.
Figure 13 illustrates the way in which we produce compound ingots to be rolled
into bars.
7 is an ingot mould and m m are iron or steel tubes set up within it and rammed
around with sand. n is the cover of the mould with pouring passages to allow of
the tubes being filled with high steel in a molten state.
Figure 14 shows the mould in plan with the cover removed.
These ingots may be rolled into bars of any desired form which will always
present a soft surface which can readily be finished with cutting tools.
The second part of our invention relates to compound steel castings which are
not intended to be forged but parts of which require to be machined. The part
requiring to be machined we cast of low carbon steel as for instance the front
portion of safe coffers and parts of the doors of safes and when such parts are
sufficiently set to be no longer fluid we pour into the mould high carbon steel or
suitable steel alloys which are difficult to cut.
We remove parts of the mould after. the setting of the low carbon steel and
substitute other portions providing space for the high carbon steel which will unite
with the low carbon steel first poured into the mould and form a solid casting.
We illustrate this part of our invention by the Figures 15 and 16. The figures
show a mould for casting a safe partly of hard steel and partly of soft steel. The
hard steel is so disposed as to cover every part of the surface which is accessible
from the exterior, excepting only the door frame which alone requires to be finished
by machinery after the casting leaves the mould and which being massive does not
require protection.
Figure 15 shows the mould prepared for casting the mild steel. A pattern of
the ordinary sort is used in the production of this mould.
A second top part is provided to the mould as is shown at Figure 16. This top
part is made from another pattern or from the first pattern with additional parts
representing the hard steel for completing the casting. After the mild steel has
beeu poured into the mould when arranged as in Figure 15 the top of the mould is
taken off and the other top previously prepared is put on. The high steel is then
poured on to the highly heated mild steel casting. The mould then appears as is
shown by Figure 16.
In like manner other fashioned articles may be cast in hard steel but with soft
parts where machining is required by the use of a duplex mould made from two
patterns or from a pattern with removeable parts.
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 means herein described for producing a compound ingot consisting in
casting an ingot in mild steel in a mould containing cores so arranged as to produce
channels or cavities in the mild steel casting then withdrawing such cores and
afterwards whilst the casting is highly heated pouring hard steel into such channels
or cavities.
2. The means herein described for casting a compound ingot, consisting in
providing an ingot mould with a cover on which are projections or cores; then
after pouring in the first metal, removing the cover and parts in connection there-
with; next substituting another cover and finally pouring the second metal into
the hollows of the ingot originally cast.
3. The means herein described for producing a compound ingot, consisting in
casting a steel ingot with passages through it, then conducting gas flames through

page_text: the passages, and, when their walls are intensely heated, filling the passages with
other steel in a fluid state.
4. The means herein described for producing a compound ingot, by setting up
iron or steel tubes within an ingot mould and pouring steel of different qualities
into the mould, the one outside and the other inside the tubes.
5. The means herein described for producing a compound bar, from an iron or
steel tube into which steel of another quality is poured, thereby forming a compound
ingot, which is then rolled or forged.
6. The means herein described for producing compound steel castings partly
hard but with soft parts where machining is required; by preparing a duplex mould
from different patterns, then pouring soft steel into the mould and when the metal
is set changing a portion of the mould and pouring in the hard steel on to the soft;
thereby obtaining a fashioned casting easily machined in the parts required to be
80 finished.
Dated this 26th day of October 1802
SAMUEL
CHATWOOD.
SAML. R. CHATWOOD.