Improvements in the Method of and Apparatus for Casting . Ordnance.
Year: 1888

page_text: COMPLETE SPECIFICATION.
Improvements in the Method of and Apparatus for Casting
.
Ordnance.
1, HERBERT JOHN ALLISON, of the firm of Allison Brothers, of 52 Chancery Lane,
London, in the County of Middlesex, Patent Agents, do hereby declare the nature of
this invention, which has been communicated to me from abroad by Richard Jordan
Gatling, of 27 Charter Oak Place, Hartford, Connecticut, United States of America,
Gentleman, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statenient :-
The object of this invention is to provide an apparatus by the use of which large
guns of peculiar construction may be formed by casting; and said invention consists
in part in the method of casting ordnance that consists in providing a central tube of
steel that will form the core or tube of the gun, and a sheet metal jacket that will
define the outside of the gun, and in pouring from below, and at points that will
produce a swirling or spiral movement of the molten metal, a quantity of mictal into
the space between this shape-defining jacket and the central core or tube; and it
further consists in the method of cooling the heated mass by causing a stream of oil
or water to, flow from below upward through the core of the inass, and by contact
therewith temper and cool the same; and it further consists in the combination of the
mold supports and the sectional mold, with the core and its supporting devices; and
it further consists in the combination and arrangement of the sectional flask, the pit,
and the peculiar braces and supports; and it further consists in other details of the
several parts of the pit, core and connecting apparatus, and their combination, as more
particularly hereinafter described and pointed out in the claims. Said invention also
consists in certain modifications of said mold, whereby the gases generated by the heat
froin the melted metal (in the fire-clay, sand, silicon, tile or other refractory substance
of which the mold is mainly composed) are conducted away, to the end that such gases
may not enter the molten metal in the mold and produce blow-holes and other faults
n the cannon being cast.
Referring to the drawings ;-
Figure is a detail view, in vertical section, of the gun-pit with the mold
emoved.
Figure 2 is a detail view, in vertical section, of a pool or basin for the molten
etal.
Figure 3 is a detail view, in vertical section, of the pit with parts of the flask shown;
[ Price Rd

page_text: all of one run-way and part of another being shown in the view, the plane of section
being at right angles to the plane of the section in figure 1.
Figure 4 is a detail view, in vertical section, of the pit and its parts, showing the
rough gun-mould as cast to shape.
Figure 5 is a top or plan view of the pit and connected parts.
Figure 6 is a detail view, in horizontal section, through the flask and gun-mold, on
a plane passing through the axis of the trunnions.
Figure 6a is a detail perspective view of a section of the gun-flask with one brace
attaclied.
Figure 7 is mainly a detail, vertical diametric section of the said gun-pit and a
modified form of mold, part of its figures (one run-way and a portion of the mold.
proper) being in elevation.
Figure 8 is a horizontal section of the apparatus on the line a-----a, of figure 7.
Figure 9 is an enlarged, horizontal, section of the mold and core on the line -----,
of figure 7.
Figure 10 is an enlarged horizontal section of one form of the core of the mold,
while figure 11 is a vertical section of the same on line b----b, of said figure 10.
Figure 12 is an enlarged horizontal section of a modification of said mold-core, the
upper part of it being on the line cc of figure 13, while figure 13 is a vertical
section of the same on the angular line e----e, of said figure 12.
Figure 14 is an enlarged longitudinal view, partly in section of one of the hollow
bolts used in the exterior mold, and also in the core.
Figure 15 illustrates a form of core in which a corrugated jacket of perforated
metal, surrounded by roping, is used, said figure being a plan or endwise view of the
same. Figure 16 is a central, vertical, section of the core shown in figure 15.
In the accompanying drawings, the letter A denotes the gun-pit, sheathed as with
brick work and iron plates, and thereby made water tight. B denotes a central
chamber, directly under the flask, to which access may be had through any con-
venient passage or opening, and in which is placed the pipe through which the
cooling medium flows through the core or tube of the gun after casting.
base-plate c, that is of great strength, and may be turned or cast to shape, is placed
on the floor of the pit in the center, and on it is located a bearer-plate c', the two plates
being kept from sliding on each other by the hollow stud d, that passes through the
central opening in the plates.
A
On the upper surface of this stud is formed a core-socket di, into which the bottom
end of the core or tube e is inserted and held against sideways play or movement. A
bolt is fitted in the hollow stud and its threaded end extends above the latter and
takes into a threaded socket in the lower end of the core or tube e, while the lower
end of the bolt, also threaded, has fitted upon it a nut f¹ that serves to lock these
several parts firmly together. This core or tube e is made of steel formed to shape by
casting, rolling or hammering, and is thoroughly tested before it is placed in position
to form the core of a gun.
ilat
The lower end of this core is firmly held in the base-plate within the pit, as already
described, while its upper end passes through a central opening in the brace
extends across the mouth of the pit, and is so formed as to hold the core or tube
in a vertical position. The base-plate and brace are also used to hold in exact position
in relation to the core or tube, a thin metal form or mold-lining that is made in
substantially the outline of the finished gun, the main body of the gun being
formed by casting the metal within the space between this lining and the core-piece
or tube.
The flask is made in section and is of iron cast to shape; each flask section being
in length but a fractional part of the whole mold, and forming a half of the cylinder,
as is clearly shown in figure 6a of the drawings. Each flask is provided, where it
adjoins the adjacent section, with an annular groove in what may be called the neck
of the section, and on the inside of the next section; so that interlocking flanges
are provided in order that when the several flask sections are fitted together these
interlocking parts will bold the flask sections together against any strain that tends to

page_text: pull them apart lengthwise; and the several parts of each section aro bolted together
so as to form complete annular sections, and in building up the flask the lower one is,
of course, first inserted. This lower section, as shown in figure 3, is provided with
projections that form elbows, to which the ends of the run-ways D are connected, and
5 through these projections and the run-ways the metal is poured into the flask.
be seen that the inlets with which the run-ways connect are located tangentially of
It will
the flask, so that the metal as it enters will be caused to move in a circle about the
core, and will be given a rotary or spiral movement that will prevent the formation of
bubbles, and will aid in causing the molten metal to weld into the outer surface of
the steel core or tube, and form a more perfect union there with than would otherwise
be possible. The space between the outside of the jacket h and the inside of the flask
is filled with sand, or similar refractory material, in the usual manner; the vent
pipes k, extending throughout the mass of sand, being perforated so as to form an
outlet or exit for the gas that passes into the said pipes and out through the upper end,
located above the cover or mouth of the pit.
This carries off all gases that may be formed within the mass of sand by the great
heat of the molten mass of metal; and for a similar purpose the vent pipes k¹ are
extended from the tops of the trunnions out through and beyond the mold.
The run-ways are built up in sections, with interlocking flanges on the sections, in
a manner similar to that already described with reference to the flask; and the soveral
parts of the sections are bolted together by bolts passing through the holes in the
flanges, as clearly shown in the drawings. These run-ways are supported against
displacement by braces 7, that extend from the run-ways to the flask, and to the bottom
and sides of the pit at suitable points, and as shown in figures 3 and 4 of the drawings;
while the flask is braced and supported by the braces 1, that, at suitable points in their
length, have an offset or bend to provide for the expansion of the flask, due to th
increased temperature when molten metal is poured in.
The gun-pit, near the bottom, is provided with an annular fire-box M, and the com-
bustion of fuel in this fire-box is permitted by the air that may be forced or drawn
into the chamber, as through the pipos m, see figure 1. It is obvious that in place of
the fire-box, as shown, gas jets may be used for heating the pits and parts of the mold
preparatory to casting.
The inner surface of the run-ways may be built up sections of pipo, or fire-clay, or
similarly protected against the mass of molten metal that flows through the run-way.
The molten metal is admitted, preferably, through the several run-ways into the
flask at the same time, and an advantage of the peculiar arrangement of the run-ways
is, as before described, that they cause a swirling or rotary movement to the molten
metal as it forms about the core or tube-piece, and this makes the grain of the metal
assume a spiral form in the mass of the cannon. The main advantage of the uso of
the sheet metal jacket his that a gun is produced in the rough more nearly of the
required size; the thin metal jacket being easily turned off or removed, in the process
of finishing the gun. And a further advantage of this feature is that the gases formed
In the sand, are excluded from the heated metal of the casting, by this sheet-metal
jacket or mold lining. And a further advantage is that by its use it is easy to centralize
the steel tube or core in the mass, preparatory to casting the gun.
There is a clear advantage gained in the method of cooling by the introduction of
luids below the mass, and forcing them in a stream up through the steel tube that
orms the center of the gun, as an improved effect is thereby gained; it affords means
or tempering the mass of the gun, either by the use of water as the cooling fluid, or oil.
The formation of a pit or man-hole under the center of the gun casting allows
ccess thereto, both before and after the gun has been cast, through any suitable
pproach, and the location of this man-hole or subway is one of the features of this
avention.
The core-piece or tube is, at its lower end, coupled to a pipe d² through which the
ooling fluid is forced through the said core or tube, while the upper end of the
tter is coupled to a pipe d' that leads the fluid to any desired outlet.
In the modified form of mould illustrated in vertical section in figure 7, the

page_text: jacket is dispensed with and the core of the mould is built upon the core-tube P,
the walls of which are perforated at frequent intervals, and provided in each of these
perforations with a hollow bolt N, extending outward therefrom, as shown in figures 8
and 9. The fluid pipe O passes through the interior of the core-tube, preferably with
an annular space between its outside and the inside of the core-tube; and that fluid
tube is coupled at its lower end to the hollow stud d, and at its upper end to the
discharge pipe d³.
The modified form of core of figures 12 and 13 differs from that of figures 10
and 11, in having solid bolts R, instead of hollow bolts N, and in using its core-tube
for a fluid pipe also, and in having vertical pipes S, perforated at frequent intervals,
arranged around the core-tube, supported by the annular shelf T, and extending
upward and open at the top of the mould; and also differs in having the sheet metal
jacket U enclosing the refractory substance of which it is mainly composed.
The interior of the flask is heavily plastered with fire-clay, sand, silicon or other
refractory substance, held in place by the help of bolts N, and the core-tube is
likewise provided with refractory coating, held in place by bolts N or R, as the case
may be. Where the hollow bolts N are used in the core, they collect the gases
generated in the mass of refractory substance of the core, by the intense heat of the
molten metal, and convey those gases into the annular space between the core-tubo P
and the fluid pipe 0 (see figures 10 and 11), whence they pass upward and out of
the end of the core-tube; and when the solid bolts R are used, the gases are collected
and conveyed away by the pipes S.
The hollow bolts N, in the exterior of the mould, collect the gases generated in
the adjacent sand or other similar substance, and convey those gases through the
walls of the flask into the body of the pit, whence they escape out of its mouth.
In the modified form of core illustrated in figures 15 and 16 the central tube P is
surrounded by a perforated longitudinally corrugated tube V, the space between said
corrugated tube and the outershell U being filled by tightly wound roping of any
suitable fibre.
The above described method of casting heavy ordnance or guns may be equally well
applied to the casting of heavy columns or like articles of metal.
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 within described method of casting guns, that consists in providing a steel
core or tube, and a sheet metal mold-lining, all substantially as described and for the
purpose set forth.
2-The within described method of casting guns, that consists in providing a steel
core or tube, and a sheet metal mold lining, and pouring into the cavity between these
parts, the mass of molten metal, introducing said metal near the bottom of the flask
and tangentially thereof, all substantially as described.
3-The method of cooling a gun casting, that consists in introducing water or oil
into the steel tube, from the bottom of the flask, and passing it in a continuous current
upward through the said tube of the gun, substantially as described.
4-In combination with the pit, the base-piece united to the hollow stud; the
hollow bolt the steel core-piece; the brace at the top of the pit, that supports the
upper end of the core-piece; and the sheet metal form or mould lining, all substantially
as described.
5-In combination with the pit having the gun casting supports, the sectional flask
and run-ways, composed of lengthwise and lateral sections interlocked and bolted
together, all substantially as described.
6-In combination with the pit having the central man-hole and its approach under
the center of the gun casting; the supporting plates with central opening; the hollow
bolt that unites the plates; the steel tube that forms the center of the gun; the brace
that extends across the top and supports the upper end of the said tube; and the lock-
nut or coupling. whereby the said tube is removably secured to the base-plate

page_text: and provides for the removal from the pit, of the gun after it has been cast, all
substantially as described.
7-The combination with a casting pit having a metallic lining, and a floor to
support the flask, of a sectional flask and runways, and the lateral brace-pieces formed
with a curve or bend whereby the expansion of the flask is provided for, all substantially
as described.
8 The flask for casting ordnance herein described, consisting of the outer sectional
part having interlocking annular grooves and projections, an inner metallic shell to
form the outline of the mold and formed with run-ways at its base leading through
the packing and the outer shell, a packing between the outer and inner shells of the
flask, and a base-piece to support the shells and packing, all substantially as
described.
9 The casting pit herein described, consisting of the outer mason work, the
metallic lining and the annular fire-box arranged at the base of the pit and having
draft-pipes substantially as described.
10 A mold consisting of an exterior flask provided with inwardly projecting
hollow bolts at frequent intervals for supporting the fire-clay, sand, silicon or other
refractory substance with which the flask is to be lined, and for collecting and removing
from that substance the gases generated therein by the heat from the molten metal in
the mold; all substantially as described.
11-A core for a mold, consisting of a tube provided with outwardly projecting
hollow bolts, at suitable intervals, for supporting the fire-clay, sand, silicon or other
refractory substance with which the tube is to be coated, and for collecting and
removing from that substance the gases generated therein by the heat from the molten
metal in the mold; all substantially as described.
12-A core for a mould, consisting of a tube provided with outwardly projecting
hollow bolts, at suitable intervals, for supporting the fire-clay, sand, silicon or other
refractory substance with which the tube is to be coated, and for collecting and
removing from that substance the gases generated therein by the heat from the molten
metal in the mold, and consisting also of a second tube within the other for the
passage of water, oil, air or other cooling medium through the length of the core, and
affording an air space between the two tubes for the egress of said gases; all
substantially as described.
13 A core for a mold, consisting of a central tube or rod provided with outwardly
projecting bolts for supporting the fire-clay, sand, silicon or other refractory substance
with which the tube or rod is to be coated, and consisting also of a series of perforated
tubes surrounding the central tube or rod, for collecting and removing from that
substance the gases generated therein by the heat from the molten metal in the mold ;
all substantially as described.
14-A core for a mold, consisting of a central tube or rod, provided with outwardly
projecting bolts for supporting the fire-clay, sand, silicon or other refractory substance
with which the rod or tube is coated; and consisting further of a series of perforated
tubes, surrounding the central tube or rod, for collecting and removing from that.
substance the gases generated therein by the heat from the molten metal in the mold;
and consisting also of a sheet metal jacket surrounding the whole; all substantially
as described.
15-A core for a mold, consisting of an inner tube, surrounded by a perforated,
longitudinally corrugated, tube; an outer shell or jacket, and a packing of spirally
wound roping within and filling the space between said outer shell and the corrugated
tube; substantially as set forth.