IMPROVE- MENTS IN CASTING METALS AND IN THE MOULDS AND CORES EMPLOYED THEREIN
Year: 1862

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, and of 166, Buchanan Street, in the City'
of Glasgow, North Britain, Gentleman, for the Invention of "IMPROVE-
MENTS IN CASTING METALS AND IN THE MOULDS AND CORES EMPLOYED
THEREIN." A communication from abroad by Joseph Harrison, of Phila-
delphia, in the United States of America, Engineer.
Sealed the 4th July 1862, and dated the 12th May 1862.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on the
12th May 1862.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, and of 166, Buchanan Street, in the City of Glasgow, North
Britain, Gentleman, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN CASTING METALS AND IN THE MOULDS AND CORES EMPLOYED
THEREIN," a communication from abroad by Joseph Harrison, of Philadelphia,
in the United States of America, Engineer, to be as follows:-
This Invention relates to certain peculiar constructions and arrangements
of moulds and cores to be employed in casting metals, but is more particularly'
applicable to the casting of the "units" of the peculiar steam generator for
which Letters Patent were granted to me on or about the 30th of August!
1859, No. 1970, and consists in forming the moulds in several parts, which
are made up either entirely of metal or fire-proof porous material, or partly

page_text: of metal and partly of sand or other fire-proof and porous material, the
several parts being in all cases so disposed as to allow for the contraction of
the casting when cooling, and if necessary prevent "chilling" or hardening of
those parts of the casting which are afterwards to be worked, facility being
also afforded for the accurate adjustment of the coro inside the mould.
According to one modification as applied to the casting of the "units" of four
spheres described in the Specification of the Patent herein-before referred to,
I employ a metal base plate having circular recesses sunk therein on its
upper surface, the centre of each recess coinciding exactly with the vertical
centro line of each sphere of the "unit." In the centre of each recess is
fitted a tapered pin made hollow or tubular and perforated to allow of a free
escape or vent for the gases. Round the base of each pin and sunk in the
recess so as to be flush with the surface of the plate is placed a disc of soap-
stone, fire-clay, or other fire-proof porous material, of sufficient diameter to
cover the neck of the "unit" to be cast. The bottom half of the mould is
now placed upon the base plate, such bottom half being composed of four
metal boxes or cases of equal size, and so formed that when adjusted together
in their proper positions an intervening space will be left between their
contiguous sides, which space is filled in with sand so as to allow the four
quarters to approach each other as the casting contracts. The interior sur-
face of cach quarter is lined with sand or other heat-resisting material to
form the proper shape of the casting, the metal edges only of the quarters
being in actual contact with the molten metal. In order to adjust theso
quarters accurately on the base plate, suitable brackets with set screws are
formed on the plate, rising up vertically therefrom, and these screws form
stops or abutments for each quarter to bear against, a wedge being driven
between the converging corners of the several quarters in the centre of the
mould for the purpose of forcing out each quarter until it bears against its
stop screw, after which the spaces between the quarters are filled in with
sand, as before described. The core to form the inner surface of the casting
or "unit" is now introduced into the lower half of the mould, it being guided
accurately therein by means of the taper pins in the base plate, which pins
enter corresponding tapered tubes enclosed inside the core. In making the
core a base plate somewhat similar to the one employed for the mould is
used, but having its entire surface planed perfectly smooth and flat, and into
this plate are fitted four tapered pins corresponding exactly in size and relative
position to those in the base plate of the mould. The core box is made of
metal corresponding in size and configuration internally. with the interior of
the unit," and divided horizontally at the centre or largest diameter of the

page_text: spheres. This box is properly adjusted on its base plate, suitable means
being employed for ensuring its central position as regards the taper pins. A
tubular tapered metal socket, having an external flange at its lower end, is
now passed on to each of the pins, the middle portion of these sockets being
enlarged so as to leave an interior space between them and their pins, and
this enlarged portion is perforated for the escape of the gases when casting.
as herein-after described. "The core having been completed by ramming in
green sand or by applying fire-clay or other suitable and porous material into
the core box, I attach to the protruding ends of each tube or socket a suitable
hook, whereby I am enabled to lift the core bodily from the lower half of
the core box, the upper half still resting upon and being elevated with the
core. The core with the upper part of its box still resting upon it, and
with its tubes or sockets enclosed therein, is now lowered into the bottoin
half of the mould or flask, the sockets being guided down the guide pins in
the base plate of the mould, hence a perfect accuracy of adjustment of the
core in its mould is ensured. In some cases the core may be made in
several parts of metal and other material on the same principle as that
adopted for the moulds, each part being small enough to be removed through
the necks of the "unit." These parts may then be re-arranged to form a
fresh core and so used several times in place of breaking up the core after
each casting. The core, having been adjusted in its mould, the top part of
the core box is removed and the upper part of the mould is completed, such
half being precisely similar in its construction to the bottom half, that is to
say, made up of four boxes or cases lined with sand or other suitable material,
and having sand interposed between the adjoining edges of the cores, as in
the lower half corresponding set screws are provided in the brackets of the
base plate for the accurate adjustment of the upper boxes in a precisely
similar manner to the lower ones. A disc of soapstone, fire-clay, or. other
heat-resisting porous material, is placed over the protruding ends of the core
sockets so as to hold the core down in its place and to close the mould,
weights being placed on the discs to keep them in position when the metal
is poured in. The gases and steam generated in casting escape through the
perforations in the enlarged portions of the sockets and enter the tubular
pins, whence they pass out at the top thereof.
According to another part of this Invention it is proposed to make moulds
entirely of iron, either solid or built up of a number of plates so disposed
that their edges will form the matrix. When solid metal moulds are used
it is further proposed, in order to allow for contraction in the casting, to open
the mould slightly, that is to say, to elevate the upper half and lower the

page_text: the
bottom half slightly so soon as the metal has set, and to keep the mould thus
open during the cooling of the casting. When moulds are made of a series
of plates, the aggregation of the interstices between the several plates
permits of the contraction of the mould with the casting, and further affords
facility for the free escape of the gases, thus serving in this respect purpose
of the sand or porous material. In cases where the inner surfaces of metal
moulds are to be coated with fire-resisting material to prevent "chilling" of
the casting it is proposed to roughen or fur such surface in order that it may
better retain the coating; should the taper pins and sockets fit each other
loosely after long usage they may be tightened up by simply raising the taper
pins slightly by the aid of a washer or otherwise.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson, in the Great Seal Patent Office on the
12th November 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,
and of 166, Buchanan Street, in the City of Glasgow, North Britain,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twelfth day of May, in the year of our Lord
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reigu, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Henry Johnson, Her special license, that I, the said John
Henry Johnson, my executors, administrators, and assigns, or such others
as I, the said John Henry Johnson, my executors, administrators, or assigns,
should at any time agree with, and no others, from time to time and all
times thereafter, during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN CASTING METALS AND IN THE MOULDS AND CORES
EMPLOYED THEREIN," a communication from abroad by Joseph Harrison,
of Philadelphia, in the United States of America, Engineer, upon the con-
dition (amongst others) that I, the said John Henry Johnson, my executors
or administrators, by an instrument in writing, under my hand and seal
or under the hand and seal of one of them, should particularly describe and
ascertain the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal Patent

page_text: Office within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said John Henry Johnson, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and by
the following statement, reference being had to the accompanying Drawings
and to the letters and figures marked thereon, that is to say :-
The said Invention relates to certain peculiar constructions and arrange-
ments of moulds and cores to be employed in casting metals, but is more par-
ticularly applicable to the casting of the units of the peculiar steam generator,
for which Letters Patent were granted to me on or about the Thirtieth day
of August, One thousand eight hundred and fifty-nine, No. 1970, and consists.
of certain peculiar constructions and arrangements of moulds and cores, and in
the mode or method of combining the same, whereby greater accuracy in the:
castings is obtained with allowance for shrinkage of the casting. The moulds
are made in several parts, which are made up either entirely of metal or heat-
resisting porous material, or partly of metal and partly of sand, or other
heat-resisting and porous material, the several parts being in all cases so
disposed as to allow for the contraction of the casting when cooling, and if
necessary, prevent "chilling" or hardening of those parts of the casting which
are afterwards to be worked, facility being also afforded for the accurate
adjustment of the core inside the mould.
And in order that the said Invention may be fully understood, I shall
now proceed more particularly to describe the same, and for that purpose-
I shall refer to the several Figures on the Sheets of Drawings hereunto
annexed, the same letters of reference indicating corresponding parts through-
out all the corresponding Figures.
Figure 1 on Sheet 1 of my Drawings represents a vertical section of
one modification of mould and core, constructed according to this Invention;.
and adapted to the casting of one of the "units of construction.." of the-
improved steam generator herein-before referred to;. Figure 2 is a horizontal
section of the same; and Figure 3 represents in isometrical perspective one of.*
the top and bottom set of boxes or cases which constitute the mould detached..
Figure 4 (Sheet 2) is a vertical section of the mould box for forming the-
core; and Figure 5 is a view shewing the core lifted. from the lower half of.
its box in the process of being transferred to the mould.
The mould is constructed upon a cast iron or other metal plate A, which
forms a base of operation. In the upper surface of this base plate are sunk four
circular recesses at B, B, the centre of each recess coinciding, exactly with the

page_text: vertical centre line of each sphere of the "unit." These recesses are about
one inch in depth, and of such a diameter as will adapt them to any desired
size of unit." In the centre of each of these recesses is secured, in any suit-
able manner, a vertical tapered pin C, which may be formed with a shoulder
near their lower ends, and a stem or shank passing through the lower plate,
and fixed in their places by nuts, as shewn in Figure 1. The pins C are made-
hollow through a portion of their length, and their sides are perforated, as
shewn, for the purpose herein-after mentioned. Fitting round these taper pins
aid filling up the recesses flush with the surface of the base plate are a series
of four discs D, D, of soapstone, fire-clay, or other suitable heat-resisting and
porous material. On the outer edge of the base plate and near the rounded
corners thereof are formed a number of vertical brackets E, E, each bracket'
being provided near its upper extremity with two set screws F, F, herein-after
more fully referred to. The first or bottom half of the mould is first placed upon
the base plate and accurately adjusted in its exact proper position; this half
of the mould is composed of four cast-iron boxes or cases G, G, one of which is
shewn in detail at Figure 3; these four boxes are all exactly alike in size and
shape, and constitute the four angles or corners of the lower half of the mould;
each box having one half of the spheres of the "unit" moulded therein in sand
or other suitable material. An intervening space I, II, is left between the
contiguous sides of these four boxes (see Figure 2), which space is filled in with
sand after each box and the core has been finally adjusted in its proper
position on the base plate, that is to say, when the vertical centre line of the
hollow sphere which is moulded inside each box coincides exactly with the
centre of the tapered pin in the sunk portion or recess of the base plate over
which the box is placed. This accurate adjustment of the boxes is facilitated
by tho set screws F, F, which are so adjusted in their brackets, that when the
boxes are forced outwards until they bear against the ends of the set screws,
they will each be in their proper positions as regards the taper pins in the
base plate. As a simple means of simultaneously forcing ontwards all the four
boxes, I propose to use a central wedge I, which is driven in between the four
flattened converging corners of the boxes, as shewn clearly in the plan,
Figure 2. The set screws F having been once properly adjusted to suit a set
of boxes will require no further alteration, and may be fixed by jam nuts.
The lower half of the mould having been completed by filling up the spaces
between the boxes and moulding the necks of the "units" therein, the central
wedge I is withdrawn, and the core inserted, as herein-after described. Ordi-
nary green sand may be used in forming the moulds inside the boxes, but as it
would be more advantageous to make a mould that could be used several times

page_text: without renewal or repairs, I prefer to line the boxes or cases with any porous
and heat-resisting material not easily liable to fracture, and capable at the same
time of producing sound castings. Or, the moulds might be composed entirely
of metal and thinly coated or painted over on their inner surfaces with any
good non-conducting material.
I will now proceed to describe the mode of making the core and of adjusting
it in its proper position in the mould. In making the core I use a base plate
A (Figure 4), somewhat similar to that employed for the mould, but having no
recesses sunk therein. Upon the upper surface of this plate are fitted four solid
taper pins B, B, corresponding exactly in size and relative position to the hollow
taper pins in the base plate of the mould herein-before referred to. The core
box C is made of cast iron, divided horizontally into two parts at the largest dia-
meter for the facility of opening and removing the core and conforming exactly
in size and shape with the interior of the "unit" to be cast. The lower portion of
this box is accurately adjusted upon the base plate A, by having a small raised
rim a, a, formed on such plate, as shewn in Figure 4, such rims being each
perfectly concentric to the pins, and of such a size as will allow of the necks
of the core box fitting accurately inside them. By this arrangement the
vertical centre lines of each sphere of the core exactly coincide with the
centres of the taper pins. A taper tube, or socket D, Figures 1, 4, and 5, of
iron or other metal, is now placed on each of the taper pins B in the base
plate of the core box, fitting the pins for about two inches of their length at
the top and bottom. These sockets are enlarged in the middle, as shewn at d;
so as to leave an interior chamber or space between the sockets and their pins,
and in the sides of the sockets at this part a number of perforations are
made for the escape of the steam and gases in casting, as herein-after
described. The entire core box is now filled and carefully rammed up with
green sand, and when finished it is lifted out of the lower half of its box by
suitable attachments or hooks E, E, secured to the protruding upper ends of
the sockets D, D, as shewn in Figure 5. Whilst the core is being thus lifted
the upper half of the core box remains upon the top of the core, and is
elevated with it (see Figure 5), being kept in its place until the core has been
deposited inside the lower half of the mould, as shewn in Figure 1. The
accurate adjustment of the core inside the mould is ensured by causing the
several sockets D contained inside the core to pass. down the corresponding
taper pins C, C, in the mould, as shewn clearly in Figure-1. In order that
the sand may adhere firmly to the sockets, I propose to form a number of
ribs or feathers e, e; round the sockets, extending from a flange ƒ formed at
their lower ends up to the enlargement in the middle of each socket, these

page_text: ribs being shewn in the transverse section at Figure 6 (Sheet 1,) taken along
the line a, b, in Figure 1; the steam and gas generated in casting finds a free
vent through the perforations in the sockets D and hollow taper pins C, and
escapes at the top of the latter.. The core having been made and adjusted in
its place in the lower half of the mould, as herein-before described, the upper
part of the core, box is removed from the top of the core, and the boxes or
cases composing the upper half of the mould are applied; these boxes or
cases are exact counterparts both externally and internally to the lower set of
boxes or cases, and are adjusted in their true positions in the same manner,
being forced outwards by a central wedge against the upper set screws. F¹, F¹.
The spaces between the contiguous sides of these boxes are then filled in with
sand, a curved strip of metal a little wider than the intervening spaces being
passed down inside the mould to prevent the sand employed in filling the
spaces from entering between the mould and the core. When each space has
been thus filled in, the metal strip is withdrawn, leaving the mould perfect.
Discs of soapstone or other porous and heat-resisting material D', D', having
a central opening therein, are now placed over the protruding ends of the tubes
or sockets D (see Figure 1), in order to close the upper part of the mould,
and weights may be applied to these discs for the purpose of keeping them
down in their proper places. The mould is now ready to receive the molten
metal, and as soon as it is run in (through suitable "gates") the casting
begins to contract by cooling, and this contraction is amply allowed for by the
sand partitions between each box or casing, which admits of the several boxes
moving inwards towards the centre and towards each other, the sand being
thus compressed between the boxes. If by long use the taper pins and
sockets for guiding the core into the mould begin to fit each other loosely,
they may be tightened up again by simply raising the pins slightly by inserting
a washer under the collar at the lower ends and screwing up tight again.
According to another part of my Invention I propose to make the moulds
of iron or other metal disposed in plates, or lamina of thin sheet metal
disposed side by side inside a metal frame, so as to present their thin edges
only to the metal when poured in, the plates being of different lengths, and so
shaped on the edge forming the mould as to produce the desired outline of the
article to be cast; the interstices between the several plates allow the mould
to contract with the contraction of the casting, and afford facility at the same
time for the free escape of the steam and gases produced when pouring in the
metal. In order to prevent "chilling" or bardening of the casting, these
moulds may be coated thinly with any good heat-resisting composition or
material. And in order the better to retain the coating of non-conducting or

page_text: heat-resisting material on the inner surfaces of metal moulds, I propose to fur
or roughen slightly those surfaces to be coated, such roughing enabling the
coating to adhere more firmly. Those parts of the castings which are after-
wards to be cut or worked may sometimes be specially protected from contact
with the metal of the mould by interposing between such parts and the mould
a piece of soapstone, or other heat-resisting porous material. Figure 1 shows
a mode of carrying out this idea, applied to the top and bottom necks of the
right-hand sphere of the "unit" in this Figure. For this purpose the boxes
or cases are recessed at L, L, so as to allow a portion of the neck to protrude
beyond the recess, and these recesses are each filled in with a disc of soap-
stone or analogous material M, M, which is so shaped as to embrace or
surround the ends of the necks, and to form the sides of the mould at those
parts.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion, that what I consider to be novel
and original, and therefore claim as the Invention secured to me by the
herein-before in part recited Letters Patent, is,-
1st, the general constructions, arrangements, and combinations of moulds
and cores employed in the casting of metals, as herein-before described.
2nd, the application and use of stationary guide pins inside the mould in
conjunction with corresponding tubular metal sockets inside the core, for the
purpose of ensuring the accurate adjustment of the coro in the mould, as
herein-before described.
3rd, the application and use of guide pins fixed to a suitable bed plate
in combination with tubular metal sockets in the manufacture of cores,
substantially in the manner and for the purpose herein-before described.
4th, the transferring of the core from the core box to the interior of the
mould without removing the upper part of the core box from the core, as
herein-before described.
In witness whereof, I, the said John Henry Johnson, have hereunto
set my hand and seal, the Tenth day of November, One thousand eight
hundred and sixty-two.
J. HENRY JOHNSON. (L.S.)