Improvements in Metal Moulds for Casting Steel Wheels.
Year: 1887

page_text: Improvements in Metal Moulds for Casting Steel Wheels.
I, JAMES YATE JOHNSON, of 47 Lincolns Inn Fields in the County of Middlesex,
Gentleman, do hereby declare the nature of this Invention which has been com-
municated to me from abroad by William Sellers of the City and County of
Philadelphia in the State of Pennsylvania, United States of America, Engineer, and
in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
In Letters Patent No. 7019 granted to John Henry Johnson under date of June 9,
1885, for Improvements in metal moulds for casting steel wheels, there is shewn and
described a mould for casting all forms of wheels, in which the rim is connected with
the hub by arms or by a plate or web that is narrower than the rim, but as perhaps
the most important application of that invention it is shown and described with
reference to the manufacture of railway wheels.
In the manufacture of all such wheels a sinking head must be provided at the hub
where the metal is poured, which increases the height from which the metal inust fall
from the ladle into the mould when poured from above, and it is at this point that it is
desirable to insert a baked sand core but it has been found impossible to insert such
a core with safety, before the metal is poured into such a mould, owing to the cutting
of the core by the molten metal and the spattering before referred to; in a sand
mould closed at the top so as to protect the upper end of the core or with an
enlarged sinking head in such a sand mould so that the core could be supported above
it, as well as at the bottom, this difficulty would not arise, but with a metal mould,
the sinking head must be no larger than the hub of the casting, otherwise the casting
could not be removed from the mould, and if the core were passed entirely through
uch a sinking head the metal remaining on each side of the core would be so thin that
it would not answer the purposes of a sinking head, as it would chill as rapidly or
perhaps more rapidly than the other parts of the casting.
The present invention is designed to obviate the difficulty of coring the hubs of
wheels cast in metal mould, without impairing the efficiency of the central sinking
head, by providing a construction whereby such core may be inserted under and
into the molten metal after the latter has been poured into the mould from above;

page_text: to such end this invention comprehends a metal mould provided with a movable
annulus adapted for the casting of steel wheels, and devices for guiding and thrusting
into the mould from the under sido a baked sand core; the operation of the mould
comprehends the pouring of the molten metal-into the mould from above until the
sinking head is full, and the thrusting of a baked sand core from below into the
molten metal up to the sinking head.
In order that this improvement may be clearly understood reference must be had
to the drawings forming part of this specification, in which Figure 1 represents a
vertical sectional elevation, through the axis of a metal wheel mould such as is shewn
and described in the Specification of the above mentioned Patont, and through the
axis of the coring apparatus embodying the subject matter of the present invention,
the parts being represented in the positions which they occupy before the metal is
poured into the mould, Figure 2, being a view similar to Figure 1, represents the
mould as containing the metal forming a wheel, the sinking head at the hubs and at
the rim, and the core, the said core being represented as thrust up to the said sinking
head of the hub, into and through the metal which forms the bub of said cast wheel.
Figure 3 is a top plan through the cylindrical bed frame I of Figures 1 and 2 the
section being in the plane of the dotted line x-x of figure 2 and sight-being taken
_in the direction of the arrows upon said line; Figure 4 is a fragmentary perspective
detail of the core, partly broken away to exhibit its contained shell, and Figure 5 is a
similar view of the head of the core carrier, the core being removed so as to expose
the nipple upon the said head."
Similar letters of reference indicate corresponding parts in all the figures.
The construction and operation of this wheel mould having been described in the
Specification of the aforesaid prior patent it is unnecessary herein to do more than.
point out the modifications which the present invention has inade in that apparatus and
to state that the word "annulus "
as used in this specification is the same as described
in the Specification of the said former Patent and is indicated upon the accompanying
drawings by the letters J. and K.
In the Specification of the aforesaid prior Patent the lower hub portion G of the
mould is described as provided with a cylindriform adjustable block or plug of
metal, the vertical position of which in the mould determines the length of the lower
hub of the wheel casting, the said block being supported at the proper height by sand
packed in between it and the floor upon which the mould rests. In the application
of the present improvements to the said mould, this block is dispensed with and the a
following construction is substituted.
I is a cylindrical bed frame of any preferred construction, upon which the lower
framo B of the mould proper is superimposed and to which it is connected by small
flanges to give it position laterally.
P is a tubular housing concentrically disposed both with respect to the bed fraine
and to the inner rim H of the mould and conveniently supported by a series of radial
websi sprung from the inner walls of the cylindrical bed frame.. The upper edges
both of the tubular housing and the radial webs are flush with the upper edges of the
bed frame, but the depth both of the housing and the webs is preferably less than the
total height of the bed frame, as will be apparent by a reference to the drawings.
The tubular housing contains a hollow cylindrical or tubular sleeve or guide Q, which,
for convenience, is termed the " core guide," which is conveniently supported on the
tubular housing P by a circumferential external shoulder q2 which is free to move and
centre itself with the lower hub portion G within said housing, and which is preferably,
although not necessarily, capped by a ring g of baked moulding material the bore of 5
which is continuous with the bore of the core bearing,—the composite bore being
cylindrical.
The said ring 9, when the core is in the position represented in Figure 1 forms in
connection with the top of the core a chamber or basin so to speak. The operation of
pouring molten metal into the mould is so conducted that the stream of molten metal
falls within this chamber, with the result that when the same becomes filled to over-
flowing a bath is provided which in the further operation of pouring receives the

page_text: stream of molten metal and prevents the spattering of the same against the walls of
the hub G.
R is what may he termed the "core carrier" the same being a plunger, follower, or
kindred contrivance of any preferred construction, adapted to support, and, under the
actuation of a lever or similar operating contrivance, have a movement longitudinally
in either direction within the core guide, so as to advance the core and subsequently
recede from it.
A good construction of the core carrier is that represented in the drawings, in
which the letter R is applied to a disc-like head mounted upon two parallel side bars r,
which spring from a tubular plunger * conveniently provided with projections >² for
the attachment of a link s connected with a lever S pivoted in one of the webs i at s*.
The carrier is also provided with a circumferentially extending basal flange serving
as a stop which, by encounter with the bottom of the core bearing, makes a fixed limit
to the upward thrust of the core carrier and core.
The cylindrical bed frame I is vertically slotted at x to permit of the play of the
lever, and the said slot is bridged by stop pins 2 to provide an adjustable limit to the
throw of the lever handle, and thereby also to limit the thrust of the core carrier
and core.
The tubular housing P is likewise vertically slotted at px and the core guide Q
at 2*, in order to permit the throw of the inner extremity of said lever.
The core W, which is mounted upon and actuated by the core carrier, is made of
suitable material, moulded and baked or dried about a perforated cylindriform shell w.
The upper extremity of this shell is capped or covered over by the substance of the
core, while the lower extremity presents an opening flush with the end face of the
lower extremity of said core which opening fits upon a tent or nipple t on the core
carrier, which hollow and preferably perforated, and which serves as a device not
only to receive and centre the core by having a perforated shell of the latter slipped
upon it, as clearly shown in the drawings, but also as a vent for the escaping gases
when and after the metal is poured.
With a core guide and carrier arranged as above described, the pouring of the
metal in the top of the mould, at the hub, may be conducted as contemplated in the
Specification of the before mentioned prior patent, and if desired, the height of
the sinking head may be increased to any extent, while the hub of the wheel may be
cored up to the sinking head with security from accident, so that when this sinking
head is cut off from the casting and the core is removed, a clear hole will be made
entirely through the hub; moreover the mass of metal in the sinking head is not
reduced nor is its efficiency as a sinking head impaired.
The foregoing are simply preferred constructions of both the core carrier and
the core, but as is manifest, other constructions of both, and other modes of
application of the core to the carrier may, if desired, be resorted to; while the core
may, of course, be made of any desired material.
The process of casting a wheel with the above described mould is as follows.
The mould frame and mould being closed and clamped together with the core
and core carrier in the position represented in figure 1, the annular portions of
the mould are closed against the rim and hub portions by rotating the cain shafts
in the upper frame. The mould and frame thus closed and clamped are, in cases
where it is found necessary, moderately heated before the cast is made, with a
view to avoid a too sudden heating from the molten metal, and the metal is then
poured rapidly at the hub until the sinking head is full. The core carrier is then,
through the depression of the levers from the position which it is represented as
occupying in Figure 1 to that shewn in Figure 2 forced upward so as to intro-
duce the core into the heart of the molten metal contained in the hub portion of
the mould. After this the mould is allowed to stand until a skin of the casting
is set, after which the lever handle is moved so as to release the annular
portions J and K, the metal in the casting being still so supported by the lower
hub and by the bottom flange on the rim that its weight cannot distort the
casting.

page_text: As fully stated in the Specification of the aforesaid former patent, the length of
time during which the annular portions of the mould must remain closed after
the cast has been made will vary somewhat with the proportions of the wheel.
It is only requisite to keep these portions of the mould closed until a skin is
formed strong enough to prevent the fluid metal in the interior of the casting from
bursting it when they are opened, and it is requisite that they should be opened
before they can present any appreciable resistance to the shrinkage of the inetal.
As soon as the metal has solidified sufficiently to permit of the removal of the
casting without distorting it, the swinging clamps and struts are thrown off, the
upper rim, with the portions of the mould attached to it, are lifted off, and
the casting with its contained core lifted out of its place. The mould may then
be reclosed as before, and the operation be repeated as often as required.
I am aware that ingot moulds have been provided with metal cores which have been
forced from the underside of the mould into and through the molten metal after the
mould has been filled therewith, and have then been withdrawn before the metal has
cooled. These devices, however, are intended to solidify the metal by pressure and to
take the place of a sinking head, whereas the present device is intended to operate in
conjunction with a sinking head and to make use of a core incapable of such insertion
as to produce a solidifying pressure.
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.
First. In combination, a metal mould provided with a movable annulus, and adapted
to the casting of steel wheels, a baked sand core and devices for guiding and thrusting
said core into the mould from its unler side, substantially as described.
Second. In combination, a metal mould provided with a movable annulus and with
a sinking head space and adapted to the casting of steel wheels, a baked sand core,
and devices for guiding and thrusting said core into the mould from its under side
and up to the sinking head space after said mould and its sinking head space have
been filled with molten metal substantially as and for the purposes described.
Dated the 1st day of November 1887.