AN IMPROVED MODE OF CASTING METALS UNDER PRESSURE, AND IMPROVED APPARATUS TO BE USED IN CASTING METALS
Year: 1878

page_text: LETTERS PATENT to William Henry Osborne Taylor, of Panteg, in the County
of Monmouth, Mechanical Engineer, for the Invention of "AN IMPROVED
MODE OF CASTING METALS UNDER PRESSURE, AND IMPROVED APPARATUS
TO BE USED IN CASTING METALS."
PROVISIONAL SPECIFICATION left by the said William Henry Osborne
Taylor at the Office of the Commissioners of Patents on the 31st October
1878.
WILLIAM HENRY OSBORNE TAYLOR, of Panteg, in the County of Monmouth,
Mechanical Engineer. "AN IMPROVED MODE OF CASTING METALS UNDER PRES-
SURE, AND IMPROVED APPARATUS TO BE USED IN CASTING METALS."
This Invention relates, firstly, to a mode of giving compression to molten metal
when supplied to rotating or revolving moulds, the object being to impart pressure
to such metal in excess of that which is due to the centrifugal action imparted to
the metal; and, secondly, to means for increasing with safety the centrifugal action
of rotary moulds, which action is limited by the speed at which it is safe to drive
them.
When casting, say, a ring with an inner flange, according to the first part of this
Invention, I form an, expanding core of segment-shaped pieces, between which are
fitted wedge-shaped pieces, the whole forming on their outer periphery a counter-
part of the inner periphery of the ring intended to be cast. A passage or passages
or runners are provided for conducting the molten.metal from the centre of motion
of the mould to the inner periphery thereof.
The core being arranged concentrically in the mould it will, when a rapid rotation
is given to the mould, expand to its full size, that size being limited by an annular
stop formed for it in the mould. Molten metal being now run into the space between
the core and the mould the head of metal will force back the compound core against
the forward pressure which it receives due to the centrifugal action put upon its
component parts, which being made of iron or other weighty material will offer con-
מ

page_text: siderable resistance to the accumulating mass of molten metal. Thus not only will
a sound casting be secured but also one shewing great density of metal. This com-
pound core being free to contract in diameter under the cooling of the metal there
will be no tendency for the casting to fracture or adhere to the core while the cooling
takes place.
To produce castings such as projectiles, whether hollow or solid, from metal under
pressure, I arrange the moulds radially in a mould box, and entering the metal at
the outer end of the mould I close the inner end of the mould with a sliding core or
cover, which by the centrifugal action imparted to it will advance against the run-
ning metal and compress the same in the mould. The cores or covers will in this
case move forwards as in radial guides and contract the moulds to the capacity
desired.
It will be readily understood that the limit of safety as respects the driving of
the rotary moulds or mould box to obtain a dense casting may be soon reached, and
therefore the degree of density thereby obtained will be limited.
In order however to impart great pressure to the metal in the moulds either with
or without the use of a moveable core, I propose to mount two, three, or more
moulds or mould boxes on vertical spindles set on a rotary frame and arranged
equi-distant from each other and from the shaft on which the frame is mounted. To
these moulds or mould boxes rotary motion will be given, and the whole will
revolve around the central shaft after the manner of a sun and planet motion. The
molten metal to be supplied to the moulds will pass from a contral supply pipe, or
channel, or feeder on the rotary frame through branch pipes or channels to feeders
which severally connect by a gland with their respective rotary moulds..
Each mould or mould box is thus left free to rotate while it receives the molten
metal at a pressure due to the centrifugal force imparted to it by the rotary
frame.
•
The metal entering the mould box at this increased pressure will now receive
a still further increase of pressure from the independent rotary motion of the mould
box, and thus a dense casting will be secured without subjecting the apparatus to
undue strain by driving it at a speed beyond the limit of safety.
Rotary motion may be imparted to the moulds or mould boxes by means of
driving bands or gearing connected with the central or rotary frame shaft.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Henry Osborne Taylor in the Great Seal Patent Office on
the 30th April 1879.
WILLIAM HENRY OSBORNE TAYLOR, of Panteg, in the County of Monmouth,
Mechanical Engineer.
"AN IMPROVED MODE OF CASTING METALS UNDER
PRESSURE, AND IMPROVED APPARATUS TO BE USED IN CASTING METALS."
This Invention relates, firstly, to a mode of giving compression to molten metal
when supplied to rotating or revolving moulds, the object being to impart pressure
to such metal in excess of that which is due to the centrifugal action imparted to
the metal; and, secondly, to means for increasing with safety the centrifugal action
of rotary moulds, which action is limited by the speed at which it is safe to drive
.them.
When casting, say, a railway tyre with an inner flange, according to the first part
of this Invention, I form an expanding core of segment-shaped pieces, between
which are fitted wedge shaped pieces, the whole forming on their outer periphery a
counterpart of the inner periphery of the ring or tyre intended to be cast. A passage
or passages or runners are provided for conducting the molten metal from the centre
of motion of the mould to the inner periphery thereof. The core being arranged
concentrically in the mould it will, when a rapid rotation is given to the mould,.
expand to its full size, that size being limited by an annular stop formed for it in
the mould. Molten metal being now run into the space between the core and the
mould the head of metal will receive a tendency to force back the compound core
against the forward pressure which it receives due to the centrifugal action put
upon its component parts, which being made of iron or other weighty material will
offer considerable resistance to the accumulating mass of molten metal. Thus
not only will a sound casting be secured but also one ensuring great density of
metal.
In Sheet I. of the accompanying Drawings Fig. 1 is a vertical section of a rotary
mould fitted with an expanding annular core, according to this part of my Invention,
for forming ring shaped castings, and Fig. 2 is a plan view of the same, the
expanding core being shewn by dotted lines.
A is the rotary mould, suitably formed for casting a flanged wheel tyre, and B
the cover for the same; Cis the central shaft on which the mould is mounted, and
it is driven by a band and pulley or other suitable driving gear.
In the centre of the cover B is the gate or opening D for the molten metal. This
gate communicates with radial covered passages D¹ which serve to conduct the
molten metal to the inner periphery of the mould, as described in the Specification
of a Patent granted to me, in conjunction with John William Wailes, and dated the
Tenth October, One thousand eight hundred and seventy-eight. E is the expanding
annular core, consisting of blocks of cast iron or other heavy material e, e¹. This
core is so arranged in the case that when the casting cools, the pieces e, e, which are
wedge shaped, will be free to move back towards the centre of motion as the casting
contracts and thus release it from the core. The segment-shaped pieces e¹, e¹, are
rebated at their edge to form an inner flange on the casting, and also to fit against
a shoulder on the bottom of the mould, which shoulder forms a stop to the segment
pieces and gauges their forward position. These segment pieces it will be under-
stood are held in contact with the molten metal by the centrifugal force due to the
rapid rotation of the mould. As the wedge shaped pieces e advance from the centre
of motion they will press against the bevilled ends of the segment pieces e¹ and
thereby retain the compound core in an expanded state. The molten metal, which
is fed in while the mould is in rapid rotation, is prevented from oxydizing by passing
through the covered channels D' to the mould. In some cases I prevent the oxida-
tion of the metal by pouring it through a non-oxidizing or but. slightly oxidizing ·

page_text: atmosphere, as, for instance, by filling the moulds before the metal is poured in
with commou illuminating gas, carbonic acid, carbonic oxide, nitrogen, or hydrogen,
or any suitable mixture of them.
The rotation of the mould is kept up until the metal has had time to solidify and
shrink. As this takes place there will be no tendency for the casting to fracture or
adhere to the core by reason of the compound core being free to contract in diameter
under the cooling of the metal.
To produce castings such as projectiles, whether hollow or solid, from metal under
pressure, I arrange the moulds radially in a rotary mould box, and entering the
metal at the outer end of the mould I close the inner end of the mould with a sliding
core, plug, or cover, which by the centrifugal action imparted to it will advance
against the running metal and compress the same in the mould. The cores, plugs,
or covers will in this case move forwards, as in radial guides, and contract the
moulds to the capacity desired.
In Sheet II., Fig. 3 shews a sectional elevation, and Fig. 4 a plan of an arrange-
ment of rotary mould box for casting projectiles from metal under pressure according
to what may be termed the second part of this Invention. In this box sand
moulds F are formed, their axes radiating from the centre of motion, and above the
moulds runners are formed in the sand to conduct the molten metal from the central
opening in the cover to the outer ends of the moulds. The inner ends of these
moulds are closed by cores of iron G which are free to slide radially in the moulds,
and which by reason of their tendency to advance (limited however by a restraining
shoulder in the sand), will compress the metal supplied to the moulds and thereby
ensure sound castings.
It may be remarked that metals of different qualities or densities may be used in
combination in casting projectiles where it is required to give hardness to the point
or forward part and comparative toughness to the rear of the projectile.
The two or more kinds of metal will in this case be supplied to the moulds in
such order that the harder metal will go to form the point, and the softer the rear of
the projectile.
It will be readily understood that the limit of safety as respects the driving of
the rotary mould or mould box to obtain a dense casting may be soon reached, and
therefore the degree of density thereby obtained will be limited.
When it is desired to obtain a greater compression of the metal than can be
obtained by driving the rotary moulds or mould boxes at a speed within safety
limits I propose to attain this end by the use of the mechanism which constitutes
the third head of this Invention, and is shewn in Sheet III. of the Drawings, where
Fig. 5 is a sectional elevation, and Fig. 6 a plan view of a compound centrifugal
machine for casting.
These Figures represent four mould boxes mounted on vertical spindles, which
are carried by a rotary frame and arranged equidistant from each other and from
the shaft on which the frame is mounted. A, A, are the mould boxes mounted on
spindles B, B, which have their bearings in the rotary frame C. This frame is
keyed to a vertical shaft D which rests in a step D¹, and is fitted with a pulley E
for receiving a driving band from any first mover. The bearings of the shaft D are
carried by a hollow standard F, to the upper end of which is fitted a fixed band
pulley G. This pulley is made sufficiently broad to receive driving bands from
pulleys on the spindles of the several mould boxes. The effect of this arrangement
is to ensure rotary motion being imparted to the spindles of the several mould boxes
while they are being carried around the shaft D by the rotating frame C; H is a
central tubular guide affixed to the rotary frame C for receiving the molten metal
which is to be discharged into the moulds. Leading from this central guide H are
branch tubular channels H, H', which channels are respectively coupled up with
elbow pipes A¹ which dip into glands formed in the covers of the mould boxes. By
thus connecting the mould boxes with the supply tube H they are left free to rotate
whilst revolving around a common axis. The mould boxes it will be seen are so
arranged as to balance each other, and these boxes may be fitted with sand or other

page_text: moulds, as shewn at Figures 3 and 4, or they may themselves, constitute moulds for
annular castings, as shewn at Figures 1 and 2. From the foregoing it will be
understood that the molten metal to be supplied to the moulds passes from the
central pipe H on the rotary frame through tubular channels H, H, to the elbow
pipes A, A, which form central feeders for the mould boxes. The metal will thence
How as described with reference to Fig. 2, entering and filling the radial moulds,
or hugging the inner periphery of the annular moulds, as the case may be. The
metal received into the inould boxes enters them at a pressure due to the centrifugal
force imparted to it by the rotary frame, and it will now receive a still further
increase of pressure from the independent rotating motion of the.mould boxes, and
thus dense castings will be secured without subjecting the apparatus to undue strain
by driving it at a speed beyond the limit of safety.
Having now set forth the nature of my Invention of "An Improved Mode of
Casting Metals under Pressure, and Improved Apparatus to be Used in Casting
Metals," and explained the manner of carrying the same into effect, I wish it to
be understood that under the above in part recited Letters Patent I claim,-
First. The use of compound expanding cores in rotary moulds for increasing the
density of annular castings and facilitating their removal from the moulds, as above
described with reference to Figures 1 and 2 of the Drawings."
Secondly. The use in rotating frames or mould boxes carrying moulds of sliding
cores or covers, as described with reference to Figures 3 and 4 of the Drawings.
Thirdly. The arrangement of apparatus described with reference to Figures 5
and 6 of the Drawings, for giving density to castings by means of centrifugal force
derived from two distinct centres of motion.
In witness whereof, I, the said William Henry Osborne Taylor, have here-
unto set my hand and seal, the Twenty-ninth day of April, in the year
of our Lord One thousand eight hundred and seventy-nine.