Improvements relating to the Casting of Metals, and to Apparatus for use in connection therewith.
Year: 1897

page_text: Date of Application, 5th Jan., 1897
Complete Specification Left, 19th July, 1897-Accepted, 21st Aug., 1897
Improvements relating to the Casting of Metals, and to Apparatus
for use in connection therewith.
I, WILLIAM ELLIS MAY, of Robarts Villa, Rowfant Road, Balham, in the County of
Surrey, Civil Engineer and Naval Architect, do hereby declare the nature of this
invention to be as follows:-
This invention relates to the casting of metals in vacuo as described in the
Specification of my former Patent No. 4549 of 1891 wherein a system of store
vacuum chambers is described in connection with working or operating chambers, in
which a vacuum is maintained whilst the casting is being performed, the objects of
my present invention being to facilitate the casting operation and to simplify the
construction of the apparatus.
In carrying out my invention I construct and arrange the working or operating
chambers as hereinafter described.
For casting ordinary ingots I provide a chamber preferably buried in the ground
to the depth of the sides and having a removable top and adapted to contain a series
of moulds. The ladle is supported in and hermetically closes a central opening in
the top of the chamber and has a hole at the bottom for running the metal, a plug
operated by any suitable mechanism being used to close the said hole.
A chute or runner has one end beneath the hole in the ladle and adapted to turn
in a bearing whilst the other end or mouth is supported by wheels on a circular
railway on which it can be moved by suitable mechanism so as to direct the metal
from the ladle to the several ingot moulds arranged in a circle. When the moulds
are filled the top and ladle can be removed and used in connection with another
series of moulds. An air-tight packing is employed between flanges on the sides and
top of the chamber and in some cases screw clamps are employed to increase the
pressure on the packing.
The chamber in which ordinary or finished castings are made is similar to that
for casting ingots the ladle, however, being advantageously arranged near the side
thereof.
For casting and compressing molten metal in vacuo especially for heavy work such
as armour plates, propeller or crank shafts and ingots for heavy guns I arrange that
the pressure exerted on the molten metal shall be sufficient to set up an expansive
force in the metal approximately equal to the contracting force due to cooling so as
to prevent piping during the cooling. The chamber and ladle used are similar to
those hereinbefore described.
For compressing the molten metal I employ the usual hydraulic press but I
arrange in conjunction with it a mould which is advantageously built up of blocks
clamped together by plates and bolts. An auxiliary hydraulic ram is employed to
adjust the position of the head of the press.
I find it advantageous to admit hot air to the working chambers especially when
casting steel, the hot air being admitted after the top and ladle are in place, and the
supply continued until the mould is sufficiently hot to receive the metal when the

page_text: hot air supply should be cut off, communication with a store vacuum chamber or
chambers opened, and the metal then run in.
In all working chambers for heavy castings I find it advantageous to have a layer
of concrete on the bottom.
$ 1.
For exhausting the air from the store vacuum, chamber or chambers I provide an
air pump or exhauster the piston of which is reciprocated by screws by any suitable
motor, means being provided whereby when the piston arrives at one end of a stroke
in one direction it shall commence to move in the opposite direction. Such means
may advantageously consist of rods projecting into the path of the piston and
adapted to be operated by the latter so as to directly or indirectly disengage a clutch
from a gear wheel on the motor shaft driving, the motor fly wheel and engage it
with another gear wheel also in connection with the fly wheel whereby the
momentum of the latter instantly reverses the movement of the piston, the motor
being also reversed by the movement of the clutch lever..
In some cases I use an auxiliary pump which draws and receives air from the
exhauster whereby notwithstanding that the air is reduced to such low tenuity in
the exhauster that its piston has to travel nearly or quite to the end of its stroke
before producing a pressure of air inside the exhauster equal to or greater than that
of the atmosphere outside the tenuity of the air will be still further reduced, the
piston of the auxiliary pump being so arranged relatively with the piston of the
exhauster that immediately the exhauster piston reaches the end of its stroke
the plunger or piston of the auxiliary pump is moved to force out the air in front of it
and at the same time extract air from the other end of the exhauster. This
compound action will allow the air to be reduced to a very low tenuity in a short
time.
The auxiliary pump may be provided with springs to act as buffers at each end
of the stroke and may be driven by any suitable motor the starting and. stopping
mechanism of which is connected to the rods projecting into the path of the
exhauster piston.
Instead of the exhauster piston being operated by screws as herein before described
it may be arranged similarly to that of the auxiliary pump the starting and
stopping mechanism of the motor of each being operated from the other by rods or
other devices projecting into the paths of the pistons.
Dated the 5th day of January 1897.
.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
Improvements relating to the Casting of Metals, and to Apparatus
for use in connection therewith.
I, WILLIAM ELLIS MAY, of Robarts Villa, Rowfant Road, Balham, in the County of
Surrey, Civil Engineer and Naval Architect, do hereby declare the nature of this
invention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
This invention relates to the casting of metals in vacuo as described in the
Specification of my former Patent No. 4549 of 1891 wherein a system of store
vacuum chambers is described in connection with working or operating chambers in
which a vacuum is maintained whilst the casting is being performed, the objects of
'my present invention being to facilitate the casting operation and to simplify the
construction of the apparatus."

page_text: In carrying out my invention I construct and arrange the working or operating
chambers as hereinafter described.
For casting ordinary ingots I provide a chamber preferably buried in the ground
to the depth of the sides and having a removable top and adapted to contain a series
of moulds. The ladle is supported in and liernetically closes a central opening in
the top of the chamber and has a hole at the bottom for running the metal, a plug
operated by any suitable mechanism being used to close the said hole.
A chute or runner has one end beneath the hole in the ladle and is adapted.to turn
in a bearing, whilst the other end or mouth is supported by wheels on a circular
railway on which it can be moved by suitable mechanism so as to direct the metal
from the ladle to the several ingot moulds arranged in a circle. When the moulds
are filled the top and ladle can be removed and used in connection with another
series of moulds. An air-tight packing -is employed between-flanges on the sides
and top of the chamber, and in some cases screw clamps are employed to increase
the pressure on the packing.
The chamber in which ordinary or finished castings are made is similar to that
for casting ingots the ladle, however, being advantageously arranged near the
side thereof.
For casting and compressing molten metal in vacuo especially for heavy work
such as armour plates, propeller or crank shafts and ingots for heavy guns I
arrange that the pressure exerted on the molten metal shall be sufficient to set
up an expansive force in the metal approximately equal to the contracting force
due to cooling so as to prevent piping during the cooling. The chamber and ladle
used are similar to those herein before described.
For compressing the molten metal I employ the usual hydraulic press but I
arrange in conjunction with it a mould which is advantageously built up of
blocks clamped together by plates and bolts. An auxiliary hydraulic ram is
employed to adjust the position of the head of the press.
I find it advantageous to admit hot air to the working chambers especially when
casting steel, the hot air being admitted after the top and ladle are in place, and the
supply continued until the mould is sufficiently hot to receive the metal when the
hot air supply should be cut off, communication with a store vacuum chamber or
chambers opened, and the metal then run in.
In all working chambers for heavy castings I find it advantageous to have a layer
of concrete on the bottom.
For exhausting the air from the store vacuum chamber or chambers I provide an
air pump or exhauster the piston of which is reciprocated by screws by. any suitable
motor, means being provided whereby when the piston arrives at one end of a stroke
in one direction it shall commence to move in the opposite direction. Such means
may a ivantageously consist of rods projecting into the path of the piston and
adapted to be operated by the latter so as to directly or indirectly disengage a clutch
from a gear wheel on the motor shaft driving the motor fly wheel and engage it with
another gear wheel also in connection with the fly wheel whereby the momentum of
the latter instantly reverses the movement of the piston, the motor being also
reversed by the movement of the clutch lever.
In some cases I use an auxiliary pump which draws and receives air from the
exhauster whereby (notwithstanding that the air is reduced to such low tenuity in
the exhauster that its piston has to travel nearly or quite to the end of its stroke
before producing a pressure of air inside the exhauster equal to or greater than that
of the atmosphere outside,) the tenuity of the air will be still further reduced the
piston of the auxiliary pump being so arranged relatively with the piston of the
exhauster that immediately the exhauster piston reaches the end of its stroke
the plunger or piston of the auxiliary pump is moved to force out the air in front of
it and at the same time extract air from the other end of the exhauster. This
compound action will allow the air to be reduced to a very low tenuity in a short
time.
The auxiliary pump inay be provided with springs to act as buffers at each end of

page_text: the stroke and may be driven by any suitable motor the starting and stopping
mechanism of which is connected to the rods projecting into the path of the exhauster
piston.
Instead of the exhauster piston being operated by screws as hereinbefore described
it may be arranged similarly to that of the auxiliary pump the starting and stopping
mechanism of the motor of each being operated from the other by rods or other
devices projecting into the paths of the pistons.
To enable my invention to be clearly understood I will describe the same by
reference to the accompanying drawings, in which :—
Figure 1 is a plan with part of the top or cover removed of a chamber constructed
according to my invention for casting ingots:
·
Figure 2 is a section on the line 2-2 Figure 1:
Figure 3 is a section through the chamber at right angles to Figure 2:
Figure 4 is a sectional view of means for clamping the top of the chamber to the
sides thereof:
Figure 5 is a plan, with part of the top removed, of a chamber for making finished
castings:
Figure 6 is a section on the line 6-6 Figure 5:
Figure 7 is a plan, with a part of the top removed, of a chamber for casting and
compressing molten metal:
Figure 8 is a section of the same on the line 8-8 Figure 7:
Figure 9 is a section on the line 9-9 Figure 8 drawn to a larger scale:
Figure 10 is a sectional plan of an air pump or exhauster constructed according to
my invention;
Figure 11 is an end elevation of the same; and,
Figure 12 is a longitudinal sectional elevation of the same drawn to a smaller
scale:
Figure 13 is a plan shewing the said air pump or exhauster provided with an
auxiliary pump :
Figure 14 is an end elevation of the same:
Figure 15 is a section on the line 15-15 Figure 13:
Figures 16 and 17 are side and end elevations respectively of the outlet valves and
their seats shewn in Figure 15 the said figures being drawn to a larger scale:
Figures 18 and 19 are an elevation and a plan of an arrangement wherein the
exhauster is constructed similarly to the auxiliary pump:
Figures 20 and 21 are sections respectively on the lines 20-20 and 21-21 of
Figure 19 drawn to a larger scale; and,
Figures 22 and 23 are end views of the valves with their seats shewn in the said
Figures 20 and 21.
Similar letters of reference indicate similar or corresponding parts throughout the
drawings.
Referring to Figure 1 to 9 a, a are the working or operating chambers which are
preferably buried in the ground to the depths of the sides and b, b are the removable
tops of the same the said top and sides of the chamber being provided with
flanges c, c between which a suitable air-tight packing d is placed, screw clamps e,
such as that shewn in Figure 4, being sometimes employed to increase the pressure
upon the packing. 61, 61 are glazed sight holes in the tops or covers b, b to enable
the operations carried on within the chambers to be observed. a¹, a¹ are the pipes
connecting the working chambers with the store vacuum chambers, a², a² being the
valves in the said pipes for shutting off communication between the said chambers.
f, f are the ladles for containing the molten metal prior to it being run into the
moulds, f, being holes at the bottom of the same for running the metal; f2, f2 are
plugs which serve to close the holes f¹, f any suitable mechanism being employed
for operating the said plugs. In the arrangement shewn in Figures 2 and 3 I have
illustrated the said plugs as being operated by a rack, pinion and star wheel g, g¹, g²
respectively, but in Figures 6 and 9 I have illustrated them as being raised by hand
evers g³.

page_text: h, h are the runners for conveying the molten metal from the ladles to the
moulds i, i. In the arrangement shewn in Figures 1, 2 and 3 the runner has one
end adapted to turn in a bearing formed in a plate beneath the ladle whilst the
other end or mouth is supported by wheels h² on the circular railway h³ on which it
can be moved so as to direct the metal from the lalle to any one of the ingot
moulds i, i the said moulds being arranged in a circle for the purpose.
Mechanism for actuating the said runner advantageously consists of a worin
wheel h* attached to the runner and a worm 5 engaging with the said worm wheel
and actuated from the outside of the chamber by a star wheel h°.
In the arrangement shewn in Figures 1 to 3 the chamber which is advantageously
circular has the ladle placed in a central opening in the top or cover 6 of the said
chamber, but in the arrangement shewn in Figures 5 and 6 and 7 to 9 the ladle is
placed near one side of the chamber. By forming the tops or covers detachable
from the chambers one top or cover can be made use of in connection with several
chambers, that is to say, after having filled the moulds in one chamber the top or
cover can be removed and used in connection with another chamber.
In Figures 5 and 6 i represents an ordinary box in which the mould is formed for
making finished castings.
In the arrangement shewn in Figures 7, 8 and 9 the mould i is adapted for
casting armour plates and comprises blocks j, j arranged at right angles to one
another, as shewn clearly in Figure 9, and clamped together by plates j¹ and
bolts . The said mould is arranged in connection with a hydraulic press in such a
manner that the rank of the press is adapted to enter and fit the mould at that end
in which is the opening ¹ for charging the mould with the molten metal, the head k²
of the press being arranged at the other end of the mould. By this arrangement it
will be seen that when the mould is charged with the metal, and the ram is moved
to compress the metal, it first of all closes the opening k¹, the movement of the ram
being continued until the pressure exerted on the molten metal is sufficient to set
up an expansive force in the metal equal to the contracting force due to cooling so
as to prevent piping during the cooling. is an auxiliary hydraulic ram for
adjusting the position of the head 2 of the press. In practice the head of the
ram is made separate from the ram proper so as to permit of changing it to suit
different moulds.
In all cases I find it advantageous to admit hot air to the working chambers
especially when casting steel, the hot air being admitted after the top and ladle are
in place, and the supply continued until the mould is sufficiently hot to receive the
metal when the hot air supply should be cut off, communication with a store vacuum
chamber or chambers opened, and the metal run in.
In all working chambers for heavy castings, such as that illustrated in
Figures 7, 8 and 9, I find it advantageous to have a layer of concrete m on the
bottom.
Referring now to Figures 10 to 21 n is my improved air pump or exhauster,
', n being the inlet and outlet valves respectively.
In Figures 10 to 14 the piston n³ of the.air pump is shewn as being double acting
and actuated by screws o, o but in Figures 18 and 19 the exhauster is composed of
two single acting pumps n with a steam cylinder p in between them, the pistons n³
of the pumps being connected to the steam piston p'. In the arrangement shewn in
Figures 10 to 13 the screws o, o are actuated from the shaft o¹ of a reversing steam
engine o² or other motor through the medium of gear wheels o³, o', o'.
I will now describe means for reversing the movement of the screws o, o, when
the piston n³ arrives at the end of a stroke.
q, q are the rods projecting through the covers of the exhauster into the path of
the piston n³ the said rods being connected by the levers q¹ and rod q2 so that they
are simultaneously actuated. One of the said rods q is connected to the slide valve
of a steam cylinder the piston of which is connected by a rod to a clutch lever 8
engaging with a clutch s¹. The clutch s¹ is designed to engage with either of two
sets of clutch teeth upon bevel gear wheels t, t the said wheels both gearing with

page_text: another bevel wheel t2 mounted upon the shaft 3 carrying the fly wheel # of the
motor o².
u, ul are a rod and lever connecting the clutch levers and the reversing
mechanism (not shown) of the motor o². With this arrangement assume the parts
to be in the position shewn in Figure 12 and the piston n³ and the fly wheel # to
be moving in the direction of the arrows. When the piston n³ arrives at the end
of its stroke it will come into contact with the rod q projecting into its path
whereby steam will be admitted to the left hand end of the steam cylinder > and
the piston of the latter will be caused to move the clutch lever s so as to
disengage the clutch s¹ from the wheel t and engage it with the wheel t¹. The
momentuin of the fly wheel then instantaneously reverses the movement of the
shaft o¹ and consequently that of the piston n' the movement of the clutch lever s
at the same time actuating the rod u and lever u¹ to reverse the engine. A similar
operation of the parts will take place when the piston n³ arrives at the other
end of its stroke, that is to say, the other rod q will be actuated and operate the
steam valve of the cylinder r so as to cause its piston to move in the opposite
direction to that herein before described whereby the clutch s¹ will be disengaged
from the wheel and engage with the wheel t, the momentum of the fly wheel t
instantly reversing the movement of the shaft o¹. In Figures 18 and 19 the
reversal of the pistons n³ is effected by the auxiliary pump in connection therewith
as hereinafter described.
In Figures 11 and 12 I have shewn a store vacuum chamber v in connection with
the exhauster, pipes v¹, v passing to the inlet valves n¹.
w, w, Figures 13, 14, 18 and 19, are the cylinders of the auxiliary pump which I
sometimes use in connection with my air pump or exhauster this pump being.
similar in construction to the exhauster shewn in Figures 18 and 19 and actuated in
a similar manner by a steam cylinder x arranged between the cylinders. In
Figures 13 and 14 the cylinders w are connected by two pipes w' to the ends of the
exhauster, outlet valves n² from the exhauster being arranged at the points w² w²,
while in Figures 18 and 19 only one pipe w' with valves is shewn.
In the arrangement shewn in Figures 13 and 14 the auxiliary pump is actuated
from the exhauster by the following means, that is to say, I connect the rod q² to the
slide valve rod xl of the steam cylinder x through the medium of the bell-crank x²,
rod x³, crank x4, shaft x³, crank and rod x7. With this arrangement it will be seen
that when the air is reduced to a low tenuity in the exhauster and the piston is
travelling in the direction of the arrow, Figure 13, the said piston will have to travel
nearly to the end of its stroke before it produces a pressure of the air inside the
exhauster equal to or greater than that of the atmosphere outside. The movement
of the piston will cause the valves at the points w², w² to open and allow the air
which is gradually becoming more dense as the piston n' nears the end of its stroke
to pass into the cylinder w. When the piston arrives at the end of its stroke and
operates the rod q², the slide valve of the steam cylinder x will be thereby operated
and admit steam so as to drive the steam piston and consequently the piston contained
in the cylinder w towards the left hand thereby expelling the contents of the cylinder w
through the outlet valves 103. A similar operation takes place in connection with
the other cylinder w when the piston n³ of the exhauster arrives at the end of
the next stroke.
In Figures 18 and 19 the devices 9 which are actuated by the piston n³ take the
form of levers connected together by the rod q² the motion of which is communicated
to the slide valve of the steam cylinder x by a lever y. The reverse movement of the
piston n³ is, however, caused by the auxiliary pump, that is to say, rods or arms z, z
are arranged in the paths of the pistons of the cylinders w the said rods being
mounted upon a bar z¹ adapted to slide in bearings 22 when the arms are moved
by the said pistons. This rod 2¹ is connected by a lever. 23 to the slide valve of the
steam cylinder p of the exhauster. It will be seen that when either of the pistons
of the cylinders w moves inwardly it will come into contact with one of the arms z
thereby actuating the slide valve of the steam cylinder p to admit steam so as to

page_text: drive the piston p' in the opposite direction to that in which the pistons of the
cylinders w have been moved and so on.
,, Figures 13, 18 and 19, are springs arranged to act as buffers against which
the pistons of the auxiliary pumps and the exhauster shewn in Figures 18 and 19
strike at each end of their strokes.
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. In apparatus for casting metals in vacuo working or operating chambers
provided with removable tops or covers, substantially as, and for the purpose,
described.
2. In apparatus for casting metals in vacuo the combination of a working or
operating chamber, a ladle, adapted to fit in an opening in the top of the chamber
and provided with a hole for running the molten metal, and a plug for closing the
said hole when required, substantially as described.
3. In apparatus for casting metals in vacuo the combination of a working or
operating chamber, a ladle adapted to fit in an opening in the top of the chamber,
a runner one end of which pivoted, and a circular railway supporting the mouth of
the runner, substantially as, and for the purpose, described.
4. In casting metals in vacuo compressing the molten metal so that an expansive
force is set up in the metal approximating to the contracting force developed when
cooling as, and for the purpose, described.
5. In apparatus for casting metals in vacuo the combination of a working or
operating chamber, a hydraulic press and a mould for the molten metal consisting
of blocks clamped together by plates and bolts, substantially as described.
6. In casting metals in vacuo heating the moulds in the working or operating
chambers by means of hot air prior to running the metal as described.
7. In apparatus for casting metals in vacuo the combination in an air pump or
exhauster, of a piston, of screws for actuating the piston and means for reversing
the movement of the piston at the end of each stroke, substantially as described.
8. In apparatus for casting metals in vacuo the combination in an air pump or
exhauster of a piston n³ screws o, o, shaft o¹, motor o², gear wheels 03, 0, 0,
rods g, 9 operatively connected, a steam cylinder the slide valve of which is
connected to one of the rods q, a clutch lever s operatively connected to the piston
of the cylinder 7, bevel wheels t, t¹ provided with clutch teeth, a bevel wheel t²,
shaft 3, and fly wheel t', all substantially as described, and illustrated in
Figures 10, 11 and 12 of the accompanying drawings.
9. In apparatus for casting metals in vacuo the combination of an air pump or
exhauster and an auxiliary pump combined and operating substantially as
herein before described and illustrated in Figures 13 and 14 of the accompanying
drawings.
10. In apparatus for casting metals in vacuo the combination of an air pump or
exhauster and an auxiliary pump combined and operating substantially as
herein before described and illustrated in Figures 18 and 19 of the accompanying
drawings.