or or Compounds thereof
Year: 1885

page_text: or Iron or Compounds thereof,
I, JAMES GRAY LAWRIE, of 2 Westbourne Terrace, Glasgow, in the County of
Lanark, North Britain, Shipbuilder, do hereby declare the nature of my said
invention for "IMPROVEMENTS IN AND CONNECTED WITH MOULDS FOR CASTING
STEEL OR IBON OR COMPOUNDS THEREOF," to be as follows, that is to say:-.
My said Invention has for its object, by improved modes of heating the moulds,
to economically obtain superior castings of steel or iron or any suitable compound
thereof.
In carrying out my Invention various materials may be used for forming the
mould but I prefer to employ for the external part of the mould, firebrick or
similar refractory material, or iron or steel, the core (when there is one) being
made of similar material when possible or convenient, or. of sand or loam, or with a
coating of sand or loam as commonly used."
.
In the case of a mould formed in iron or steel I have the mould heated to a high
temperature, preferably as high as may be without the metal becoming so soft as
to be easily distorted. When the mould is formed in a refractory material such as
firebrick the mould may be heated to a temperature nearly as high as that of the
molten metal which is to be poured into it.
When the metal to form the casting is poured into a mould heated as described
it preserves a uniform condition throughout, no part of it being subjected to
chilling action, and as it will cool and set very slowly it will be tougher and of
more uniform strength than ordinary castings. In this way large castings with
comparatively small thicknesses may be satisfactorily produced; and as the mould
and casting will cool together, there will be little or no liability to the occurrence
of injurious strains due to unequal contraction.
In heating the mould for the purposes of my Invention I employ ignited or
highly heated gases, the same being economically obtained by means of regene-
rative or heat-restoring apparatus of the kinds known as Siemen's or Gorman's or
analogous apparatus, producer gas or solid fuel being used as the source of heat.
In some cases the ignited or highly heated gas may be passed through the matrix

page_text: or mould space into which the metal is to be cast; but in most cases I form a
number of small passages through what would otherwise be the solid part of the
mould, such passages being made as closely as conveniently may be to the mould
surfaces, and I cause the ignited or highly heated gases to pass through these
passages.
.
When the moulds are made in iron or steel or in a refractory material such as
firebrick as hereinbefore described the same moulds may be used repeatedly,
very little preparation of them being required between the successive casting
operations.

page_text: or Iron or Compounds thereof.
I, JAMES GRAY LAWRIE, of 2 Westbourne Terrace, Glasgow, in the County of
Lanark, North Britain, Shipbuilder, do hereby declare the nature of my said
invention for "IMPROVEMENTS IN AND CONNECTED WITH MOULDS FOR CASTING
STEEL OR IRON OR COMPOUNDS THEREOF." and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement, that is to say:-.
:
My said Invention has for its object, by improved modes of heating the moulds,
to economically obtain superior castings of steel or iron or any suitable compound
thereof.
In carrying out my Invention various materials may be used for forming the
mould, but I prefer to employ for the external part of the mould, firebrick or .
similar refractory material, or iron or steel, the core (when there is one) being
made of similar material when possible or convenient, or of sand or loam, or with
a coating of sand or loam as commonly used.
In the case of a mould formed in iron or steel I have the mould heated to a high
temperature, preferably as high as may be without the metal becoming so soft as
to be easily distorted. When the mould is formed in a refractory material such as
firebrick the mould may be heated to a temperature nearly as high as that of the
molten metal which is to be poured into it.
'
When the metal to form the casting is poured into a mould heated as described
it preserves a uniform condition throughout, no part of it being subjected to
chilling action (unless specially arranged to be so) and as it will cool and set very
slowly it will be tougher and of more uniform strength than ordinary castings.
In this way large castings with comparatively small thicknesses may be
satisfactorily produced; and as the mould and casting will cool together, there
will be little or no liability to the occurrence of injurious strains due to unequal
contraction.
In heating the mould for the purposes of my Invention I employ ignited or
highly heated gases, the same being economically obtained by means of regene-
rative or heat-restoring apparatus of the kinds known as Siemens' or Gorman's or
analogous apparatus, producer gas or solid fuel being used as the source of heat.
In some cases the ignited or highly heated gases may be passed through the matrix
or mould space into which the metal is to be cast; but in most cases I form a
number of small passages through what would otherwise be the solid part of the
mould, such passages being made as closely as conveniently may be to the mould
or matrix surfaces; and I cause the ignited or highly heated gases to pass through
these passages.

page_text: •
When the moulds are made in iron or steel or in a refractory material such as
firebrick as herein before described the same moulds may be used repeatedly,
very little preparation of them being required between the successive casting
operations.
Two sheets of explanatory drawings are hereunto appended showing examples of
moulds with accessory parts as constructed for carrying out my Invention. An
important application of my present Invention is for making weldless corrugated
steel boiler-furnace shells in accordance with the Invention described in the
Complete Specification appertaining to my application for Letters Patent No 14451
of 1884; and figures, 1, to 4, on sheet, 1, of the drawings show apparatus for
casting such furnace shells, figure, 1, being a plan with a half cover removed, and
figure, 2, a vertical section. Figures, 3, and 4, are respectively a plan and a vertical
section of the mould separate from the rest of the apparatus. Figures, 5, and 6, on
sheet, 2, are a plan and a vertical section showing the application of my Invention
for casting shells for ordnance; and figures, 7, to 10, show modifications of moulds
for casting such shells. In these drawings the same reference numerals are used
to mark the same or like parts wherever they are repeated.
On a base plate, 6, (figures, 1, 2,) there are erected or placed four cylinders,
7, 8, 9, 10, which are internally arranged to act as regenerative chambers of the
kind used with steel-making and other regenerative furnaces, and to the bottoms
of" which are connected pipes, 11, provided with valves in the usual manner for
leading air and gas into the regenerative chambers and. for leading the used gases
to the chimney, the gas used being the ordinary producer gas. From the tops of
the regenerative chambers, 7, 8, 9, 10, the gases are directed by means of a
cover, 12, made in two parts and composed of or lined with firebrick, this cover
'being made with hollow spaces or passages indicated by dotted lines in figure, 1, for
the gases.
The regenerative chambers, 7, 8, 9, 10, are arranged so that the mould in its
casing or box, 13, can be lowered into the central space between them. The
external part, 14, of the mould for the corrugated furnace shell is represented as
built up of suitably shaped firebricks; and it is made in two halves which are
bolted or otherwise fixed together with the core, 15, or internal part of the mould
between them. The mould box or casing, 13, is fixed down upon a bottom plate, 16,
which also supports the core, 15; and when the parts of the mould have been
suitably prepared and fixed together the whole is deposited by means of a crane or
other suitable hoisting apparatus in the space left for it between the regenerative
chambers, 7, 8, 9, 10.
For the purpose of heating the mould a number of passages, 17, are formed down
through the outer part of it; and at the. bottom these passages, 17, communicate
with each other by an annular passage, 18, extending round the mould whilst at
the top the passages, 17, are open to the hollow spaces or passages of the half
covers, 12. The space in one of the half covers, 12, communicates with and covers
one half of the passages, 17, in the mould and the space in the other half cover
communicates with and covers the other half of the passages, 17. One half cover, 12,
communicates with and covers a pair, 7, 8, of the regenerative chambers, the
other half cover communicating with and covering the other pair, 9, 10; and
accordingly as the valves of the pipes, 11, are adjusted the heated air and gas pass
from one pair of regenerative chambers to the other pair proceeding on their way
between the pairs of regenerative chambers down one half of the passages, 17, in
the mould and up the other half of those passages. The gas and air issuing from
the top of one pair of the regenerative chambers mix in the hollow space of the
half cover, 12, and being therein ignited (through a hole in the cover provided for
the purpose) proceed in an ignited condition through the mould passages, 17, and
heat the mould to the desired extent, the surfaces of the actual mould space or
.matrix into which the steel is to be cast being heated by conduction from the
passages, 17, and without the ignited gases being in contact with those surfaces

page_text: themselves, so that the blackening or surface coating is not liable to be burnt off or
injured.
Any suitable core may be employed for shaping the interior of the corrugated
furnace shell. The one shown in the drawings is formed of loam or other suitable
mould material upon a hollow collapsible core bar, 19, consisting of an iron or steel
shell cut through longitudinally at one part at which a narrow plate, 20, is inserted
when the shell, 19, is in its distended state as shown in the figures. The core
shell, 19, is distended or expanded to a larger diameter than that which it has when
cast or otherwise formed; and when the plate, 20, is drawn inwards the core shell
tends to spring in or collapse of itself. The plate, 20, is held in position by levers, 21,
centered on the sides of the core shell, 19, and connected by a rod, 22, to a hand
lever, 23, which can be moved from the outside. In order to make sure of and
expedite the collapsing of the core bar or shell, 19, when required, chains, 24, fixed
to the core shell at one side of the opening, and passing over pulleys, 25, attached
to the core shell at the other side are combined in one chain, 26, which, after the
mould has been placed in position is hooked to a weighted lever, 27, arranged below
the base plate, 6; and whenever the plate, 20, has been drawn inwards by means of
the lever, 23, after a cast has been made, the weighted lever, 27, assists in making
the core shell, 19, collapse so as to relieve the core from the interior of the
casting. The complete core, 15, is held in proper position in the mould by the
bottom of its shell, 19, fitting within a circular projection on the bottom plate, 16,
of the mould box, whilst the top of the core shell, 19, fits within an iron ring at the
top of the mould box.
The molten steel is made to enter the actual matrix or mould space at the
bottom so as to rise in filling it, a long gate or passage, 28, being provided in the
outer mould for the molten steel to be poured in by, and this passage, 28, communi-
cating at its bottom with an annular space, 29, giving equal access to all parts of
the bottom of the matrix.
Apparatus like that shown in figures, 1 to 4, and hereinbefore described, but with
the form of the matrix suitably modified and made to correspond with the
dimensions of the article to be cast, may be used for casting iron or steel pipes or
columns or similar articles; and in many cases when the castings are to be of
ordinary castiron the entire mould or a part of it may be made of iron or steel,
passages (17) such as shown in figures, 1, to 4, and hereinbefore described being
formed for the heating gases and the arrangements otherwise being such as are
hereinbefore described.
In figures, 5, and 6, only the mould for casting an ordnance shell is shown but it
is to be understood that the regenerative chambers and other parts of the
apparatus for the heating gases are the same, substantially as those shown in
figures, 1, and 2, and herein before described. The outer part, 14, of the mould is
made of firebricks and an ordinary core, 31, is provided this oore being carried by a
perforated pipe, 32, through which the gases or vapors escape from the core when
it is heated. Figures, 7, and 8, represent a mould for an ordnance shell of a kind
having a smaller cavity that that for which the mould shown in figures, 5, and 6,
is intended. The mould shown in figures, 7, and 8, is made entirely of steel or
castiron; and as it is intended that the solid point shall be chilled to a certain
extent, the passages, 17, for the heating gases are represented as extending only
part way down from the top of the mould. Some of the passages, 17, are
indicated by dotted lines as extending down further than others for the purpose of
partially heating the lower parts of the mould. Figures, 9, and 10, represent a
mould which differs from that shown in figures, 7, and 8, merely in having the
upper part of the interior of the mould formed of firebricks, whilst the lower part
is of steel or castiron and is intended to have a chilling action on the solid point of
the shell.
A single mould box may be constructed, together with the accessory apparatus,
for casting two or more shells or other articles at one operation.

page_text: Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed I declare that what
I claim is
1. The heating of moulds in which steel or iron or a compound thereof is being
cast, substantially in the improved manner hereinbefore described.
2. The combination of regenerative gas heating apparatus with moulds for
casting steel or iron or compounds thereof substantially as and for the purposes
herein before described.
2
3. The constructing of moulds for casting steel or iron or compounds thereof
with passages for the passage of ignited or highly heated gases for heating the
moulds such passages being separate from the matrix or mould space in which the
metal is to be cast substantially as herein before described.
EDMUND HUNT,
Applicant's Agent.