Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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AUTOMATED VARIABLE DIMENSION MOLD
AND BOTTOM BLOCK SYSTEM
CROSS REFERENCE TO RELATED APPLICATION
This application does not claim priority from any other application.
TECHNICAL FIELD
This invention pertains to an automated variable dimension mold and bottom
block
system, resulting in a desired castpart taper or configuration.
BACKGROUND OF THE INVENTION
Metal ingots, billets and other castparts may be formed by a casting process
which
utilizes a vertically oriented mold situated above a large casting pit beneath
the floor level of
the metal casting facility, although this invention may also be utilized in
horizontal molds.
The lower component of the vertical casting mold is a starting block. When the
casting
process begins, the starting blocks are in their upward-most position and in
the molds. As
molten metal is poured into the mold bore or cavity and cooled (typically by
water), the starting
block is slowly lowered at a pre-determined rate by a hydraulic cylinder or
other device. As
the starting block is lowered, solidified metal or aluminum emerges from the
bottom of the
mold and ingots, rounds or billets of various geometries are formed, which may
also be referred
to herein as castparts.
While the invention applies to the casting of metals in general, including
without
limitation, aluminum, brass, lead, zinc, magnesium, copper, steel, etc., the
examples given and
preferred embodiment disclosed may be directed to aluminum, and therefore the
term
aluminum or molten-metal may be used throughout for consistency even though
the invention
applies more generally to metals.
While there are numerous ways to achieve and configure a vertical casting
arrangement,
Figure 1 illustrates one example. In Figure 1, the vertical casting of
aluminum generally
occurs beneath the elevation level of the factory floor in a casting pit.
Directly beneath the
casting pit floor 101 a is a caisson 103, in which the hydraulic cylinder
barrel 102 for the
hydraulic cylinder is placed.
As shown in Figure 1, the components of the lower portion of a typical
vertical
aluminum casting apparatus, shown within a casting pit 101 and a caisson 103,
are a hydraulic
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cylinder barrel 102, a ram 106, a mounting base housing 105, a platen 107 and
a bottom block
108 (also referred to as a starting head or starting block base), all shown at
elevations below the
casting facility floor 104.
The mounting base housing 105 is mounted to the floor lOla of the casting pit
101,
below which is the caisson 103. The caisson 103 is defined by its side walls
103b and its floor
103a.
A typical mold-"table asserribly 1-10 is-also shown in Figure 1, which can be
tilted as
shown by hydraulic cylinder i l l pushing mold table tilt arm 110a such that
it pivots about
point 112 and thereby raises and rotates the main casting frame assembly, as
shown in Figure 1.
There are also mold table carriages which allow the mold table assemblies to
be moved to and
from the casting position above the casting pit.
Figure 1 further shows the platen 107 and starting block base 108 partially
descended
into the casting pit 101 with castpart 113 (which may be an ingot or a billet
being partially
formed. Castpart 113 is on the starting block base 108, which may include a
starting head or
bottom block, which usually (but not always) sits on the starting block base
108, all of which.is
known in the art and need not therefore be shown or described in greater
detail. While the
term starting block is used for item 108, it should be noted that the terms
bottom block and
starting =head are also used in the industry to refer to item 108, bottom
block is typically used
when an ingot is being cast and starting head when a billet is being cast.
While the starting block base 108 in Figure 1 only shows one starting block
108 and
pedestal, there are typically several of each mounted on each starting block
base, which
simultaneously cast billets, special tapers or configurations, or ingots as
the starting block is
lowered during the casting process.
When hydraulic fluid is introduced into the hydraulic cylinder at sufficient
pressure, the
ram 106, and consequently the starting block 108, are raised to the desired
elevation start level
for the casting process, which is when the starting blocks are within the mold
table assembly
110.
The lowering of the starting block 108 is accomplished by metering the
hydraulic fluid
from the cylinder at a pre-determined rate, thereby lowering the ram 106 and
consequently the
starting block at a pre-determined and controlled rate. The mold is
controllably cooled during
the process to assist in the solidification of the emerging ingots or billets,
typically using water
cooling means.
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There are numerous mold and casting technologies that fit into mold tables,
and no one
in particular is required to practice the various embodiments of this
invention, since they are
known by those of ordinary skill in the art.
The upper side of the typical mold table operatively connects to, or interacts
with, the
metal distribution system. The typical mold table also operatively connects to
the molds which
it houses.
When metal is cast using a continuous cast vertical mold, the molten metal is
cooled in
the mold and continuously emerges from the lower end of the mold as the
starting block base is
lowered. The emerging billet, ingot or other configuration is intended to be
sufficiently
solidified such that it maintains its desired profile, taper or other desired
configuration. There
is an air gap between the emerging solidified metal and the permeable ring
wall. Below that,
there is also a mold air cavity between the emerging solidified metal and the
lower portion of
the mold and related equipment.
Once casting is complete, the castpart, an ingot in this example, is removed
from the
bottom block. Figure 1A illustrates an exemplary bottom block configuration
with a castpart
113 being removed from the bottom block 108 after casting. Figure IA
illustrates a bottom
block 108 with a particular shape or configuration in the internal cavity
which receives the
initial flow of molten metal during the casting process, and the outer
perimeter of the castpart
113 once solidified takes that shape.
Figure 1A illustrates sloped portions 115 & 116, and indented' portion 119 on
castpart
113. Sloped portions 115 & 116 generally correspond to bottom block
indentations 117 & 114
in shape and configuration, and with some variance generally related to
shrinkage or other
casting factors. Bottom block protrusion 118 corresponds in shape and
configuration to
Castparts indentation 119, all as can be seen in Figure 1A. The sloped
portions 115 & 116 in
prior art ingots have been different angles, such as thirty degrees, forty-
five degrees, and sixty
degrees.
Figure 1 B is an elevation cross sectional view of a prior art mold wall 142
with casting
surface 142a, castpart 141, mold framework 143, coolant chamber 149, coolant
impact zone
146 where the coolant (typically water) hits and cools the castpart 141.
Embodiments of this
invention may be applied to prior art of all types, including the mold
configuration illustrated in
Figure 1 B.
In conventional casting and direct chill casting processes for rolling ingot,
an ingot goes
through a substantial transformation process during rolling. Ingot may be
rolled into plate, can
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stock, aluminum foil and other products of differing dimensions and
thicknesses by a process
which sends the ingot through a series of rollers repetitively, with the
rollers being sequentially
moved closer together. This rolling equipment may be referred to as a rolling
stand.
One of the problems associated with this process is that a portion of the
rolling ingot is
wasted due to a phenomenon sometimes referred to as alligatoring. Alligatoring
occurs during
the rolling process when metal from the main body of the ingot gets rolled and
pushed over the
end-of-the -ingot-on- the -head and the butt--sides. -When the -ingot is
observed in this condition
from the side view the head and the butt resemble the mouth of an alligator,
which is where the
term alligatoring originated. Alligatoring is illustrated in Figure 9. During
the rolling process,
the ends of the ingots which exhibit alligatoring are cut off, thereby
resulting in a substantial
amount of waste of aluminum which must be reheated and re-cast, in addition to
the expense of
doing so.
In some prior art, it has been shown that by producing an angle with a tapered
head and
butt, alligatoring may be reduced or eliminated.
It is an object of some embodiments of this invention to provide an automated
variable
dimensioned mold casting and bottom block system which provides tapered and
other
configurations of castparts.
It is an object of some embodiments of this invention to provide an automated
variable
dimensioned mold casting system which reduces end crop losses.
Other objects, features, and advantages of this invention will appear from the
specification, claims, and accompanying drawings which form a part hereof. In
carrying out the
objects of this invention, it is to be understood that its essential features
are susceptible to
change in design and structural arrangement, with only one practical, and
preferred embodiment
being illustrated in the accompanying drawings, as required.
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BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are described below with reference to
the
following accompanying drawings.
Figure 1 is an elevation view of a prior art vertical casting pit, caisson and
metal casting
apparatus;
Figure lA is an elevation view of a particularly shaped prior art bottom block
and
corresponding castpart being removed therefrom;
Figure 1 B is an elevation cross sectional view of a prior art mold wall or
casting surface
cooling and interfacing with a castpart;
Figure 2 is a cross-sectional schematic top view of a typical fixed prior art
mold casting;
when
Figure 3 is an elevation schematic representation of the bottom portion of a
castpart
expanding in a horizontal direction during the casting process;
Figure 4 is a cross-sectional top schematic view of an embodiment of a
perimeter wall
of the mold, illustrating potential directions of movement of sidewalls;
Figure 5 is a top view of one embodiment of a mold casting system contemplated
by
this invention, wherein two of the perimeter walls-are movable;
Figure 6 is a top view of one embodiment of a mold casting system contemplated
by
this invention, wherein two of the end perimeter walls are movable;
Figure 7 is a representative elevation view of one example of an ingot which
may be
produced as a product of embodiments of this invention, illustrating tapering
at the top and
bottom portions of the ingot;
Figure 8 is an elevation view of a typical castpart ingot, with some shrinkage
and
associated cracking shown in the corners;
Figure 9 is an elevation view of the ends of an ingot such as that shown in
Figure 8,
after rolling operations, and generally illustrating alligatoring;
Figure 10 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system, wherein the bottom block is wider than
the starting
position or width of the movable walls;
Figure 11 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system, wherein the movable mold walls allow
the bottom
block to be started within the movable mold walls;
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Figure 12 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system, part way into the casting process as
the bottom block
is being lowered;
Figure 13 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system, further into the casting process and
illustrating how
the castpart may be molded dimensionally wider than the bottom block;
Figure 14 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system, still further into the casting process
from Figure 13;
Figure 15 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system, illustrating the ability of aspects of
this invention to
affect the profile or configuration of the top of the castpart at the end of
the cast;
Figure 16 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system, illustrating a castpart partially into
the casting
process wherein this invention provides a different dimension and taper or
configuration on one
side of the castpart compared to the other side;
Figure 17 is a schematic representation of an aspect of an automated variable
dimension
mold and bottom block system contemplated by this invention, illustrating a
differently
configured bottom block the approximate width of the mold opening;
Figure 18 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system, illustrating another aspect of this
invention, wherein
a liquid cooling is utilized within the bottom block to achieve more desirable
cooling of the
molten metal relative to the bottom block;
Figure 19 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system, illustrating another aspect of the
invention wherein
the movement of the mold side walls is not linear;
Figure 20 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system, illustrating an aspect of the
invention similar to that
shown in Figure 19, only wherein one of the mold walls is moved at a
dissimilar angle from the
other mold wall to provide a different dimension and/or configuration on one
side of the
castpart compared to the other side;
Figure 21 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system, illustrating a differently formed or
configured mold
wall;
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Figure 22 is a schematic representation of another aspect of the invention
with a
differently configured bottom block and which need only have full height side
walls on two
sides, wherein said aspect may use the mold walls as part or all of the
perimeter wall on the
other two sides;
Figure 23 is a schematic representation of the embodiment of an automated
variable
dimension mold and bottom block system illustrated in Figure 22, showing the
end of the
- -- - - -- - - - - -
bottom block and the absence of bottom block end walls;
Figure 24 is a schematic representation of one embodiment of a possible mold
starting
block configuration for some aspects of this invention, and which may be
utilized in
embodiments of this invention of the perimeter wall on two sides only;
Figure 25 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system, illustrating another aspect of this
invention, wherein
a liquid cooling system is utilized within the bottom block to achieve more
desirable cooling of
the molten metal relative to the bottom block;
Figure 26 is a schematic representation of another aspect of the invention,
which
includes a castpart top cap being lowered on to the top of the molten metal at
the top of the
castpart;
Figure 27 is a schematic representation of the embodiment of the invention
illustrated in
Figure 26, where the top cap has been imparted onto the top of the castpart
thereby causing the
molten metal to take the contour or configuration of the side of the top cap;
Figure 28A is a schematic representation of the embodiment of the aspect of
the
invention illustrated in Figures 26 and 27, exiting the lower part of the mold
cavity with a
particular shaped top cap;
Figure 28B is a schematic representation of the embodiment of the aspect of
the
invention illustrated in Figures 26 and 27, exiting the lower part of the mold
cavity with a
differently shaped top cap;
Figure 28C is a schematic representation of the embodiment of the aspect of
the
invention illustrated in Figures 26 and 27, exiting the lower part of the mold
cavity with yet
another differently shaped top cap;
Figure 29 is a schematic representation of yet another aspect of the
invention, wherein
any electromagnetic field is utilized to form the top of the castpart at the
end of the casting
process;
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Figure 30 is a schematic elevation representation of exemplary movements which
may
be made by movable mold walls contemplated in embodiments of this invention;
Figure 31 is an elevation view of a castpart profile or configuration of which
may be
produced as or part of the casting system disclosed by aspects of this
invention;
Figure 32 is detail 32 from Figure 31;
Figure 33 is a block flow diagram of one embodiment of a process which may be
utilized in embodiments of this invention;
Figure 34 is an elevation view of another aspect of this invention,
illustrating another
design of an ingot that may be produced as part of this invention;
Figure 35 is a schematic diagram of an embodiment of a control system that may
be
utilized to control mold side wall movement in practicing aspects of this
invention;
Figure 36 is a schematic elevation representation of one configuration of mold
walls or
casting surfaces that may be utilized in some aspects of this invention,
illustrating a top and a
bottom beveled surface area on each mold wall;
Figure 37A is a schematic elevation representation of one configuration of
mold walls
or casting surfaces that may be utilized in some aspects of this invention,
illustrating two top
and two bottom beveled surface areas on each mold wall;
Figure 37B is a schematic elevation representation of one configuration of
mold walls
or casting surfaces that may be utilized in some aspects of this invention,
illustrating a top and a
bottom beveled surface area on each mold wall, with each beveled area combined
with a curved
or arcuate surface area;
Figure 37C is a schematic elevation representation of one configuration of
mold walls
or casting surfaces that may be utilized in some aspects of this invention,
illustrating a top and a
bottom curved or arcuate surface area on each mold wall;
Figure 37D is a schematic elevation representation of one configuration of
mold walls
or casting surfaces that may be utilized in some aspects of this invention,
illustrating a top and a
bottom beveled surface area on each mold wall, with the top beveled surface
area having a
dissimilar angle dimensions that the bottom beveled surface area;
Figure 37E is a schematic elevation representation of one configuration of
mold walls or
casting surfaces that may be utilized in some aspects of this invention,
illustrating a top beveled
surface area combined with a curved or arcuate bottom surface area on each
mold wall;
Figure 38A is a schematic elevation representation of one configuration of
mold walls
or casting surfaces, at what may be the initial startup phase of casting in
one embodiment of the
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invention, wherein the molten metal level is initially in the middle portion
623a of the mold
walls;
Figure 38B is a schematic elevation representation of one configuration of
mold walls
or casting surfaces, at what may be a second phase of casting in one
embodiment of the
invention, wherein the molten metal level has been raised from that shown in
Figure 38A such
that it is at the upper portion 623b of the mold walls;
Figure 38C is a schematic elevation representation of one configuration of
mold walls
or casting surfaces, at what may be a third or steady state phase of casting
in one embodiment
of the invention, wherein the molten metal level is at the middle portion 623a
of the mold
walls;
Figure 38D is a schematic elevation representation of one configuration of
mold walls
or casting surfaces, at what may be a third or steady state phase of casting
in one embodiment
of the invention, wherein the molten metal level is at the lower portion 623c
of the mold walls;
Figure 39 is a schematic elevation representation of one configuration of mold
walls or
casting surfaces in one embodiment of the invention, illustrating the top
portion of the castpart
being formed into a taper at a pre-determined angle;
Figure 40 is a schematic elevation representation of one configuration of mold
walls or
casting surfaces in one embodiment of the invention, illustrating why the
molten metal level
needs to be maintained in the lower portion of the mold walls to prevent metal
freeze from
blocking the further inward movement of mold walls in creating the top taper;
Figure 41 is a schematic elevation representation of one configuration of mold
walls- or
casting surfaces in one embodiment of the invention, illustrating an upper
portion with a
beveled surface forming a tapered castpart bottom portion in combination with
the bottom
block; and
Figure 42 is a schematic elevation representation of a mold and bottom block
configuration which illustrates another feature of some embodiments of this
invention, wherein
the mold walls can be moved outwardly to accommodate the expansion of the
bottom block on
startup.
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Many of the fastening, connection, manufacturing and other means and
components
utilized in this invention are widely known and used in the field of the
invention described, and
their exact nature or type is not necessary for an understanding and use of
the invention by a
person skilled in the art or science; therefore, they will not be discussed in
significant detail.
Furthermore, the various components shown or described herein for any specific
application of
this invention can be varied or altered as anticipated by this invention and
the practice of a
specific application or embodiment of any element may already be widely known
or used in the
art or by persons skilled in the art or science; therefore, each will not be
discussed in significant
detail.
The terms "a", "an", and "the" as used in the claims herein are used in
conformance with
long-standing claim drafting practice and not in a limiting way. Unless
specifically set forth
herein, the terms "a", "an", and "the" are not limited to one of such
elements, but instead mean
"at least one".
It is to be understood that this invention applies to and can be utilized in
connection
with various types of metal casting and pour technologies and configurations,
including but not
limited to both hot top technology and conventional pour technology. The mold
therefore
should be able to receive molten metal from a source of molten metal, whatever
the particular
source type is. The mold cavities in the mold should therefore be oriented in
fluid or molten
metal receiving position relative to the source of molten metal.
Aspects of this invention control the dimensions of the head and butt of
ingots through
an automated variable dimension mold and bottom block system. In some
embodiments of
this invention for example, the two rolling face sides of the mold would move
in and out
relative to each other, thereby providing tapering of the ingot. The bottom
block may be
narrower in thickness than the nominal thickness of the ingot, and at the
beginning of the cast,
the mold sides may be positioned inward towards the center of the ingot and
adjacent to the
sides of the bottom block. At the start of the cast, the sides of the mold
would be gradually
moved outward at a rate that would form the desired dimensions on the butt of
the ingot,
resulting in any one of a number of different desired forms depending upon the
application.
Once the ingot dimensions reach the desired nominal ingot thickness for
rolling, the mold walls
would be held constant in position. Then, at the end of the cast, the mold
walls will gradually
be moved in until the head of the ingot (the top portion) has reached the
desired dimensions, at
which time the cast would be completed. It will be appreciated by those of
ordinary skill in the
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art that the ingot top portion is sometimes referred to as the head of the
ingot, and the bottom
portion of the ingot sometimes referred to as the ingot butt, or butt of the
ingot, as the ingot is
in the vertical casting position.
Aspects of this invention also contemplate a process which may be utilized in
some
embodiments of this invention which include controlling cast variables such as
the metal level
control, cast speed and the rate at which the sides of the mold are moved.
During casting, there may be three phases which are considered for control to
produce a
more desirable castpart, namely startup casting, steady state casting and
ending casting, with
steady state casting being that between startup and ending casting. Different
control
parameters may be desired for each of these phases of casting, and more phases
may be
introduced to divide any one or more of these into sub-phases, depending on
the desired
castpart results.
The shape of the mold face may also play a role in the process in some
embodiments of
this invention. For instance, at the beginning of the cast when the mold walls
are moved
outward from the center of the ingot, the metal level may be kept above a
certain level relative
to the mold or mold walls. Then, near the end of the cast, when the mold sides
are brought
back inward towards the center of the ingot, the metal level may be dropped to
a lower level
between certain points which are within a certain range between the mold
walls, with a specific
angle of the mold walls. The angle of the mold walls may also be dependent on
the cast speed
and the rate at which the mold walls are moved in. This may also be done where
the design of
the mold is such that the angle between points on the mold wall is essentially
equal to the angle
of the desired castpart.
Ingot castparts may come in any one of a number of different lengths, widths
and
configurations, generally ranging from fifteen feet to twenty five feet in
length. The
cross-sectional dimensions of a twenty foot long ingot may for instance be
thirty inches by
seventy two inches, or alternatively may be twenty inches by sixty inches.
It is also believed that a deeper bottom block may assist in reducing or
eliminating
liquations and bleeds of the castpart so that the castpart may be able to
support its own form by
the time the bottom block emerges below the mold walls. Generally prior art
includes
configurations wherein the bottom block was wider than the mold cavity and
could not be
extended into the mold cavity. Aspects of this invention on the other hand
allow for the
bottom block to be inserted into the mold cavity which allows more time for
the molten metal
to remain and cool within the bottom block before additional weight from
additional casting is
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placed on that initial metal, which allows that lower part of the solidifying
castpart to better
support the form of the ingot as a whole via solidification. In other aspects
of the invention,
external or internal cooling within the bottom block may assist this support.
There is a secondary benefit to engaging the block through the mold, and that
is because
clearance between the spout and block is maintained at normal industry
standards. Another
such benefit is preventing massive oxidation, which is made possible with
movable mold walls
which seal or reduce the mold to gap sufficiently to prevent bleed-outs when
the block passes
through the mold and metal rolls over the starting block rim contacting the
mold.
It will be appreciated by those of ordinary skill in the art that the term
bottom block may
also be referred to as a starting head, dummy block, stool cap, or a starting
block, all commonly
used in the industry to refer to the same general components.
While others have recognized the problem and attempted to taper or configure
the
castparts or ingots in more desirable ways, they have done so by machining or
cutting the
castpart after it is molded and solidified, which is a more costly and time-
consuming procedure
which still results in an undesirable amount of inetal which must be scrapped,
re-melted and
then recast. Other have also attempted to taper the castpart(s) by casting
into starting heads
with angles greater than thirty degrees, which only affects the bottom portion
of the castpart.
This invention on the other hand allows forming or configuring castparts at
both the top and
bottom end during the molding process, without the need to machine the
castpart thereafter.
Figure 1 is an elevation view of a typical prior art vertical casting. pit,
caisson and metal
casting apparatus, and is described in more detail above.
Figure 2 is a cross-sectional schematic top view of a typical fixed or static
prior art mold
casting perimeter wall 120, including outer surface 123, inner perimeter wall
surface 122, mold
cavity 124 and a plurality of lubricant delivery apertures 121.
Figure 3 is an elevation schematic elevation representation of the bottom
portion of a
castpart 126 thickness in a horizontal direction during the casting process.
Figure 3 shows
mold walls 125, mold opening 129, castpart 126, with downward arrows 128
showing the
movement of the castpart downwardly. Starting block 127 is shown and butt
swell distance
130 is shown to illustrate the thicker portion at the bottom of the castpart
126. Generally the
.30 bottom portion may be thicker because there may be more shrinkage in the
middle portion of
the castpart, and less shrinkage at the bottom portion.
The bottom portion of the castpart is sometimes referred to as the butt or
butt portion of
the castpart, and it tends to be thicker, which is sometimes referred to as
"butt swell". The
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illustration of butt swell may be exaggerated in Figure 3 for illustrative
purposes and the
specific amount of swell depends upon numerous parameters in the molding
process, which are
generally know by those of ordinary skill in the art. It will be appreciated
by those of ordinary
skill in the art the significant amount of time and money that is spent to
remove butt swell from
the castpart, requiring that metal be sent to scrap and requiring substantial
expense in the
process.
Figure 4 is a cross-sectional top schematic view of an embodiment of a
perimeter wall
140 of an aspect of a mold system contemplated by this invention, illustrating
potential
directions of movement of the mold wall or mold sidewalls. Figure 4
illustrates the mold side
walls 141, mold end walls 142, with arrows 144 indicating the potential
movement of sidewalls
141, and arrows 145 indicating the potential movement of end walls 142.
Figure 5 is a top view of one embodiment of a mold casting system 160
contemplated
by this invention, wherein two of the rigid perimeter walls, a first side and
a second side, are
movable. Figure 5 shows inner surface 163 of sidewalls of the mold and inner
surfaces 164 of
the perimeter wall with the mold cavity 162 in the center. Framework 161 may
be any one of a
number of different frameworks generally.
It will be appreciated by those of ordinary skill in the art how the castpart
form or
configuration can be manipulated by adjusting one or more of the cast
parameters in
combination with the movable walls, parameters such as cast speed, cast
length, metal level,
vertical height of castparts, rate of movement of the mold walls inward or
outward, as the case
may be, as well as other cast parameters. It will further be appreciated that
aspects of the mold
system disclosed by this invention may create any one of a number of different
forms and
configurations of castparts, including substantially linear sides, arcuate,
convex and concave
head and butt sections such that any slice is generally rectangular in shape.
Due to the number
of potential objectives and variables for a given casting, no one set of
parameters is desired for
this invention, but instead this invention provides and additional casting
control system with
additional parameters, to work toward the optimization of the resulting
castparts.
It will be appreciated that the movement of the mold walls may mechanically be
accomplished in any one of a number of different ways, such as by motors
causing the
movement. A motor operatively connected to a first side wall of a mold
framework may for
example be controlled by a servo drive, which may be controlled by a
programmable logic
controller ("PLC"), which may be controlled or configured via a human machine
interface
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("HMI"). It will be noted that other types of mechanical drives and controls
may be utilized
within the contemplation of this invention.
Figure 6 is a top view of one embodiment of a mold casting system 160
contemplated
by this invention, wherein two of the end perimeter walls, a third side and a
fourth side, are
movable. Figure 6 illustrates framework 161, inner surface 164 of end wall,
inner surface 163
of sidewalls, mold cavity 162, wherein end walls moved to the positions shown
by hidden lines
identified as inner surface 164 of end walls of the perimeter wall.
Figure 7 is a representative elevation view of one example of an ingot 201
which may
be produced as a product of embodiments of this invention, illustrating
tapering at the top and
bottom portions of the ingot 201. Figure 7 illustrates a potential resulting
form or
configuration of a castpart 200, with width 202, height 203, with arrow 204
representing the
lineal distance for the arcuate portion of castpart 201, which may also be an
angled portion.
Figure 7 shows a top portion 201 a, a middle portion 201 b and a bottom or
lower portion 201 c,
of castpart 201. It will be noted that with embodiments of this invention, the
form of the top,
middle or lower portions may be cast as desired in a controlled way and the
top portion 201 a
may be configured and angled differently than the bottom portion 201 c,
including by a different
method or apparatus. For instance the bottom portion may be formed by a
particularly
configured bottom block internal cavity as illustrated in Figure lA while the
top portion 201a
may be configured utilizing the embodiments of this invention which for
instance utilize
moving walls.
Figure 7 also illustrates angle 199 on the rolling surface of the castpart.
While angle
199 may be any angle within the contemplation of this invention, in some
embodiments it is
preferred that angle 199 be between twenty-one degrees and twenty-nine
degrees, such as at
twenty-six degrees. While numerous factors may affect the preferred angle 199
for a castpart
201 to be later rolled, in some applications of this invention twenty-six
degrees may be
preferred. Figure 7 also illustrates how a castpart it may be treated
differently in different
'sections or portions and figure 7 in particular shows three portions, a top
portion 201 a, a middle
portion 201b and a lower portion 201 c. For cast management and control, it
will be
appreciated by those of ordinary skill in the art that the castpart 201 may be
theoretically
divided into any one of a number of different portions in order to achieve the
desired resulting
castpart, with no one in particular being required to practice the invention.
While prior attempts to affect the shape of the ingots have taught away from
this
method (i.e. post-casting trimming of the castpart, shaping the bottom block),
this invention has
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the advantage of being able to form the desired castpart as desired, such as
by tapering both the
top portion and the bottom portion of the castpart.
Figure 8 is an elevation view of a typical castpart ingot, with some shrinkage
and butt
swell. Figure 8 illustrates castpart 210, corners 211, with castpart thickness
212.
Figure 9 is an elevation view of the ends of an ingot 210 such as that shown
in Figure 8,
after having been rolled, and generally illustrating alligatoring. Figure 9
illustrates castpart
width 217, alligatoring 216 and 215 at opposing ends of castpart 210. It is
generally known by
those of ordinary skill in the art that alligatoring is an unwanted and
undesirable result of
rolling.
Figure 10 is a schematic elevation representation of one embodiment of an
automated
variable dimension mold and bottom block system 230, wherein the bottom block
235 is wider
than the starting position or width of the movable walls. Figure 10
illustrates spout 231,
movable walls 233 and 234, starting block 235, molten metal 237 delivered by
spout 231 via
metal flow 232. Starting block 235 in this aspect of the invention is a width
238 with drive
cylinder 236 providing the lowering of the castpart during casting. Arrows 240
and 241
illustrate the respective movement of mold walls 233 and 234, respectively.
Figure 11 is a schematic elevation representation of one embodiment of an
automated
variable dimension mold and bottom block system 250, wherein the movable mold
walls allow
the bottom block 256 to be started between the movable mold walls 254 and 255.
Figure 11
illustrates spout 251, molten metal 252 being delivered to starting block 256
and shown as 253
accumulating within starting block 256. Starting block 256 has an approximate
thickness 259
and arrows 257 reflect downward movement of cylinder 258 and starting block
256. Mold
walls 254 and 255 are shown, and this invention contemplates, that the mold
walls 254 and 255
will be moved outwardly during the casting process. Figure 11 further
illustrates how in some
embodiments of the invention, the internal angles 239 within a bottom block
256 may be
utilized to achieve a particular form on the bottom of the ingot. This type of
forming
combined with other aspects of this invention may be utilized to achieve a
castpart which is
formed on the top portion and the bottom portion without the need to later cut
or machine to
achieve this.
It will be appreciated by those of ordinary skill in the art that it is
generally more
desirable to reduce the pour drop, which is the distance from the spout to the
location where the
molten metal lands or is deposited in or on the bottom block. It will be
evident to those of skill
in the art comparing the pour drop in Figure 10 to that in Figure 11, the
benefits which may be
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achieved in aspects of this invention by allowing the bottom block to be
raised up higher in the
mold cavity and between the movable mold walls, such as movable mold walls to
254 and 255.
Figure 12 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system 250, part way into the casting process
as the bottom
block 256 is being lowered. Figure 12 shows first movable wall 254, movable as
indicated by
arrows 261, second movable wall 255 as reflected by arrows 262. The system 250
illustrated
in Figure 12 further shows molten metal 252 from spout 251, accumulated metal
253 with
arrows 261 and 262 reflecting the respective movements of mold walls 254 and
255.
Figure 13 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system 250, further into the casting process
compared to
Figure 12, and illustrating how the castpart 253 may be molded dimensionally
wider than the
bottom block 256. Figure 13 illustrates first movable wall 254, second movable
wall 255 as
indicated by arrows 261 and 262 respectively. The system 250 includes spout
251, molten
metal 253, starting block 256 and starting cylinder 258. Some dimensions are
shown in the
figure, namely width 267 of starting block 267, with the cylinder 258, with
starting block 256
having a width dimension of 256, whereas ingot 253 has been cast at the outer
dimension
greater than the outer dimension of the starting block 256 in the same
direction. Distance 264
represents the additional dimension on that side of the ingot 253 by which the
ingot 253
exceeds the dimension of starting block 256, and distance 265 represents the
additional
dimension on the opposing side of the ingot 253 by which the ingot exceeds the
dimension of
starting block 256.
Figure 14 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system 250, still further into the casting
process from Figure
13, with the castpart 253 being further formed. Since like numbers represent
like items and
components from Figure 13, each will not be further identified and discussed
here in relation to
Figure 14, since they are sufficiently identified and discussed with respect
to Figure 13.
Figure 15 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system 250, illustrating the end portion of
the cast and which
shows the ability of aspects of this invention to affect the form or
configuration of the top of the
castpart 253. Arrows 261 illustrate how mold walls 254 and 255 may be moved
inwardly at
the end part of the casting process to affect the corner form and
configuration of castpart 253.
It will be appreciated by those of ordinary skill in the art that any one of a
number of different
forms and configurations may be programmed into such a system to achieve the
desired profile
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and form of the castpart 253, with no one in particular being required to
practice this invention.
In fact a feature of some aspects of the invention is the ability to produce
any one of a number
of different forms of castparts 253 for the specific application. Since like
numbers represent
like items and components from Figure 13, each will not be further identified
and discussed
here in relation to Figure 15, since they are sufficiently identified and
discussed with respect to
Figure 13.
Figure 16 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system 250, illustrating a castpart 253
partially into the
casting process wherein this invention provides a different dimension and form
on one side of
the castpart compared to the other side. Figure 16 illustrates how aspects of
this invention may
be utilized to create asymmetrical castparts 253 if desired, in that one side
may be provided
with different dimensions when compared to the opposing side. Figure 16 shows
a different
distance from the center of the castpart 253 represented by arrow 265 as
compared to arrow 264
on the opposing side of the castpart 253. It will be appreciated by those of
ordinary skill in the
art that the ability to produce asymmetrical parts is not limited to
dimensions as shown in
Figure 16, but can also be utilized to produce different forms and
configurations on one side of
the castpart 253 versus another side of the castpart 253. Since like numbers
represent like
items and components from Figure 13, each will not be further identified and
discussed here in
relation to Figure 16, since they are sufficiently identified and discussed
with respect to Figure
13.
Figure 16 also illustrates how in some embodiments of the invention that the
angle of
the upper surface 254a of the mold wall 254 may correspond to the
corresponding angle 253a
on the lower portion of the resulting castpart, and similarly the angle of the
upper surface 255a
of the mold wall 255 corresponds to the corresponding angle 253b on the lower
portion of the
resulting castpart. In practice, the angles 253a and 253b may be one degree or
more different
than the corresponding angle on the top portions 254a and 255a of mold walls
254 and 255.
Figure 17 is a schematic representation of an aspect of an automated variable
dimension
mold and bottom block system contemplated by this invention, illustrating a
differently
configured bottom block 269 which is the approximate width of the mold
opening.
Figure 17 further shows another aspect of invention, illustrating grooves 269a
vertically
oriented around bottom block 269. These grooves 269a may provide a conduit and
surface
area through which coolant may be passed to further assist and cool the bottom
block 269 and
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molten metal contained therein. Another cooling means is shown and described
relative to
Figure 18 below.
Figure 17 further illustrates another bottom block 269 configuration wherein
angled
sides 270 may be provided in the bottom block 269 to form the bottom portion
of a resulting
castpart to create the desired form for later rolling the castpart 269. This
aspect may be utilized
in combination with other aspects to create the desired form or configuration
of the castparts on
both the top portion and the bottom portion, all within the contemplation of
this invention. For
instance, the bottom portion of the castpart illustrated in the Figure 34 may
be produced
utilizing a bottom block 269 such as that shown in Figure 17. Since like
numbers represent
like items and components from Figure 13, each will not be further identified
and discussed
here in relation to Figure 17, since they are sufficiently identified and
discussed with respect to
Figure 13.
Figure 18 is a schematic representation of another aspect of an automated
variable
dimension mold and bottom block system, illustrating a liquid cooling system
utilized within
the bottom block 292 to achieve more desirable cooling of the molten metal 291
relative to the
bottom block 292. Figure 18 shows the bottom block 292 cooling system wherein
the cylinder
258 is utilized to house the cooling system 294, wherein the cooling system
may be comprised
of cooling conduit 293 operatively connected to cooling system components 294
to provide
sufficient cooling to solidify the molten metal comprising castpart 291 during
the initial part of
the cast. Those of ordinary skill in the art will appreciate that any one of a
number of different
types of cooling systems, cooling system components and locations for the
cooling system, may
be utilized within the contemplation of this invention, with no one in
particular being required
to practice this invention. Since like numbers represent like items and
components from Figure
13, each will not be further identified and discussed here in relation to
Figure 18, since they are
sufficiently identified and discussed with respect to Figure 13.
Figure 19 a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system contemplated by this invention,
illustrating an aspect
of the invention wherein the movement of the mold side walls 300 and 301 are
not necessarily
linear like in prior figures, but instead are pivoted or alternatively moved
outwardly and
inwardly to affect the form of the castpart according to arrows 302 and 303.
Mold wall 300
may for instance be moved downwardly to angle 305 and mold wall 301 may be
moved
angularly downward to angle 306, to provide the desired castpart form as the
bottom block 294
is lowered during casting. It will be appreciated by those of ordinary skill
in the art that the
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specific outer form of the mold walls 300 and 301 may be configured for
specific applications
and different forms and corners may be utilized to achieve different resulting
castpart
configurations. Figure 19 further illustrates spout 251, cylinder 258 and
bottom block 294. It
will further be noted that the pivotal mounting of mold walls 300 and 301 may
be in a cam or
other configuration to accomplish the desired castpart result, all within the
contemplation of
this invention.
Figure 20 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system contemplated by this invention,
illustrating an aspect
of the invention similar to that shown in Figure 19, only wherein one of the
mold walls is
moved at a dissimilar angle from the other mold wall to provide a different
dimension and/or
form on one side of the castpart compared to the other side. Angle 305 in
Figure 20 is a
different or dissimilar angle to angle 306 on the opposing mold wall, to
provide the
asymmetrical mold configuration or to provide a differing form on one side of
the castpart 293
compared to the other side of the castpart 293. Since like numbers represent
like items and
components from Figure 19, each will not be further identified and discussed
here in relation to
Figure 20, since they are sufficiently identified and discussed with respect
to Figure 19.
Figure 21 is a schematic representation of one embodiment of an automated
variable
dimension mold and bottom block system 320 contemplated by this invention,
illustrating
differently formed or configured mold walls 322 and 323. The spout 321
delivers molten
metal, the mold walls 322 and 323 each may be independently moved as indicated
by arrows
324 and 325. This system 320 shows a molten metal 329 becoming part of
castpart 327,
molten metal surface 330, and a more solidified surface 328. Mold walls 322
and 323 have
more beveled ends instead of rounded ends, and arrows 332 and 333 illustrate
the exit portion
of the mold walls 322 and 323 during the casting process and as the castpart
327 is being
solidified.
Figure 21 further illustrates a further aspect of this invention wherein the
mold walls
322 and 323 may be moved upward or downward linearly or in some other pattern,
as indicated
by arrows 324a and 325a. This vertical movement in particular will allow some
flexibility in
controlling the distance from spout 321 to the molten metal surface 330, as
well as the position
of specific mold wall geometries to the metal level. It is more difficult due
to other equipment
and molten metal delivery systems, to move the spout 321 in many situations.
While Figure 21
illustrates that the angle of the top portion and lower portion of mold walls
322 and 323 may be
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at twenty-seven degrees, that angle can be any one of a number of different
angles, with no one
in particular being required to practice the invention.
Figure 22 is a schematic representation of another aspect of the invention
with a
differently configured bottom block, and wherein the bottom block need only
have full height
side walls on two sides, wherein said aspect may use the mold walls as part or
instead of the
side wall on the other two sides. Figure 22 shows first movable mold wall 356,
second
movable mold wall 357, which respectively move according to arrows 358 and
359, bottom
block 354 with bottom block interior surface 354a and sidewalls 354b and 354c.
Figure 22 also
shows spout 351 at original height 352 and lowered to distance 353 from bottom
surface 1354a
of bottom block 354. The sidewalls 354b and 354c are height 355, all within
the
contemplation of this aspect of the system 350. It will be appreciated that
instead of moving
the spout vertically, the mold or mold walls may also be moved vertically
relative to the spout
to accomplish the desired casting, all within the contemplation of this
invention.
It will be appreciated by those of ordinary skill in the art that the mold or
the spout 351
may be moved upwardly and downwardly to achieve different desired results
during casting.
The height of the spout may be one of the casting parameters which may be
adjusted or
balanced to achieve the desired results. For instance as shown in the
schematic in Figure 30,, the
molten metal level will preferably be at or near the top of mold walls just
before the mold walls
are moved outwardly to achieve a different form and configuration. This will
provide some
buffer so that as the mold walls are moved outwardly it does not create a
bleed out or leak
situation with the molten metal contained between the respective mold walls.
Conversely, just
before the mold walls are moved closer together, it would be preferable to
have the molten
metal level lower on the mold wall so that it will only rise up toward the top
of the mold wall
and not over during the inward movement of mold walls in the process.
Figure 23 is a schematic representation of the embodiment of an automated
variable
dimension mold and bottom block system 350 illustrated in Figure 22, showing
the end of the
bottom block 354 and the absence of bottom block end walls. Figure 23 also
shows spout 351
at height 352, mold wall 356 and mold wall 357, with arrows 358 and arrows 359
respectively
indicating movement of the two mold walls. Inner surface 354a of bottom block
354 is also
shown.
Figure 24 is a schematic representation of one aspect or embodiment of a
possible mold
starting block configuration for some aspects of this invention, and which may
be utilized in
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embodiments of this invention of the perimeter wall on two sides only. Figure
24 shows
bottom block 354 with bottom surface 354a, sidewalls 354b and 354c.
Figure 25 is a schematic representation of another possible embodiment of an
automated
variable dimension mold and bottom block system 380, illustrating another
aspect of this
invention wherein a liquid cooling system is utilized within the bottom block
382 to achieve
more desirable cooling of the molten metal relative to the bottom block 382.
Figure 25 shows
spout 381, first movable mold wall 385 shown movable by arrow 386, second mold
movable
mold wall 387 shown movable by arrow 388, with arrows 389 indicating downward
movement
or lowering of the starting block 382 during the casting process. Inner
surface 391 has depth
390 receiving molten metal from spout 381.
Those of ordinary skill in the art will appreciate that any one of a number of
different
types of cooling systems, and cooling system components may be utilized to
provide cooling to
the bottom block 382. Cooling system 383 with a coolant conduit 384 is one
example as
coolant is routed through the bottom block and provides cooling to better
solidify molten metal
deposited on bottom block 382 by spout 381. Another example of a way to
provide additional
cooling to a bottom block is illustrated in Figure 17, wherein cooling
channels or grooves are
provided in the bottom block to receive coolant that is primarily utilized on
the solidifying
molten metal.
Figure 26 is a schematic representation of another aspect 400 of the
invention, which
includes a castpart top cap 406 being lowered (as indicated by arrows 407)
onto the top of the
molten metal at the top of the castpart 405. Figure 26 further shows first
mold wall 403,
second mold wall 404, spout 401, arrow 402 indicating that spout 401 may be
moved upwardly
out of the way after the pouring of molten metal ceases. Alternatively and as
represented by
arrows 415a and 416a in Figure 27, this movement may also be accomplished by
the vertical
movement of mold walls 403 and 404 as shown, which toward the end of the cast
would be
downward. Aspects of this invention provide for the tapering or shaping of the
upper end of
the ingot or castpart 405.
Figure 27 is a schematic representation of the aspect 400 of the invention
illustrated in
Figure 26, where the top cap 406 has been imparted onto the top of the
castpart 405 thereby
causing the molten metal to take the form of the inside of the top cap 406,
and in this example
forming a radius at the corners as indicated by items 412 and 413. Arrows 407
indicate that
downward pressure or movement may be placed upon top cap 406 to prevent molten
metal
from escaping between top cap 406 and mold walls 403 and 404. Arrows 415a and
416a
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illustrate how mold walls 403 and 404 may be moved vertically (although the
movement need
not be limited to linear movement vertically), during the casting process, in
order to provide
more desirable clearances with the spout 401, or for other casting control
reasons. Figure 27
further illustrates how mold walls in aspects of this invention may be moved
both vertically and
horizontally with the horizontal movement of the mold walls being indicated by
arrows 415b
and 416b, as shown.
Figure 28A is a schematic representation of the aspect 400 of the invention
illustrated in
Figures 26 and 27, as the castpart 405 is exiting the lower part of the mold
cavity. The mold
cavity is the area generally between first mold wall 403 and second mold wall
404. Figure
28A also shows spout 401, arrows 415a and 416a showing downward movement of
mold walls
403 and 404, castpart top cap 406 on solidifying castpart 405. Arrows 414
indicate the general
movement of the top cap 406 with the castpart 405. It will also be noted that
alternatively, the
top cap 406 may be maintained on or relative to mold walls 403 and 404 while
filling at cast
end to created the top shape without spout movement, in which case the tope
could be cooled
by liquid or air and cold be made out of a refractory or a metal in various
embodiments of the
invention. Figure 28A further illustrates how mold walls in aspects of this
invention may be
moved both vertically and horizontally with the horizontal movement of the
mold walls being
indicated by arrows 415b and 416b, as shown.
Figure 28B is the same schematic representation of the aspect 400 of the
invention as in
Figure 28A, only wherein the top cap 406 has a different configuration to
achieve a differently
shaped top portion of the castpart 405c. Figure 28B illustrates a top cap
wherein the sides are
angled and the middle portion indented as illustrated by indent angles 406c.
Figure 28B
further illustrates how mold walls in aspects of this invention may be moved
both vertically and
horizontally with the horizontal movement of the mold walls being indicated by
arrows 415b
and 416b, as shown.
Similarly, Figure 28C is the same schematic representation of the aspect 400
of the
invention as in Figure 28A and Figure 28B, only wherein the top cap 406 has a
different
configuration to achieve a differently shaped top portion which includes
tapered side angles and
which consequently results in side angles in the top portion of castpart 405a.
Figure 28C
further illustrates how mold walls in aspects of this invention may be moved
both vertically and
horizontally with the horizontal movement of the mold walls being indicated by
arrows 415b
and 416b, as shown.
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The ability to move the mold walls 403 and 404 in the direction indicated by
arrows
415a and 416a (generally vertical) provides the enhanced ability to utilize a
top cap 406 to
configure the top portion of the castpart 405a, along and in combination with
the mold walls
403 and 404 being movable in the horizontal direction (as shown in other
figures).
Figure 29 is a schematic representation of yet another aspect 430 of the
invention
wherein an electromagnetic field (represented by arrows 443 and 444) is
utilized to form the top
of the castpart433 at the end of the casting process. Figure 29 shows spout
431, movable
according to arrow 432 in an upward direction, top surface 446 of castpart 433
being formed
through the imparting of a magnetic force or magnetic field on, at or near the
top surface 446.
A magnetic device 436 and 437 may be moved toward or away from the top surface
446 of
castpart 433 in order to achieve the desired form of the top portion of
castpart 433. Mold walls
434 and 435 are shown just below the magnetic devices 436 and 437, although
they may be
adjacent or even below mold walls 434 and 435, all within the contemplation of
this invention.
There is a type of casting referred to as Electro Magnetic Casting, the
acronym being EMC,
which may also be used to provide the forming or tapering of the top portion
of the castpart
toward the end of casting, as shown in an exemplary manner in Figure 29.
Figure 30 is a schematic representation of an aspect 450 of this invention,
illustrating
exemplary movements which may be made by movable mold walls 451 and 452, as
contemplated in some aspects of this invention. Figure 30 shows varying
distances between
mold walls 451 and 452 to illustrate movement thereof. It will be appreciated
by those of
ordinary skill in the art and is shown in other figures that the movement need
not be
symmetrical, but instead can be programmed to achieve other results that may
be desired in
asymmetrical patterning of castparts. Hidden lines 451 a and 452a show a
second position of
mold walls 451 and 452, and hidden lines 451b and 452b show further possible
movement
positions of the mold walls, along with any intermediate position in between.
Figure 30 also serves to illustrate how casting parameters such as controlling
the molten
metal level between levels 457 and 458 for example, may be utilized in
combination with
aspects of this invention. For instance when mold walls are spaced apart as
indicated by arrow
455, the molten metal level 457 may be preferable if the mold walls are later
going to be moved
outwardly as indicated by arrows 456 and 457. Conversely if the mold walls 451
and 452 are
spaced apart the distance indicated by arrow 453, and the process will have
the mold walls 451
and 452 move together, then molten metal level 458 may be more desirable to
allow for the
reduction in the mold cavity area and which would naturally cause the molten
metal level 458
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to rise as the mold walls 451 and 452 move together. This may also serve to
prevent binding on
the ingot or castpart as the mold cavity is reduced. It would be preferable
that the molten metal
level 458 not rise above the mold walls as the mold walls are moved inwardly,
as will be
appreciated by those of ordinary skill in the art.
Figure 30 also illustrates how one molten metal mold in embodiments of this
invention
may be used to cast castparts of different sizes, such as cast a twenty-one
inch ingot in a first
casting, and a nineteen inch ingot in a second casting. Since prior molds are
generally
dedicated to one size, embodiments of this invention provide more flexibility
in a
manufacturing facility and reduce the change-out of molds that would otherwise
need to be
accomplished to cast castparts of different widths. In those embodiments,
distance 455 would
represent a first castpart with a first thickness, distance 454 would
represent a second castpart
with a second thickness, and distance 453 would represent a third castpart
with a third
thickness. It will be noted that there are a number of different thicknesses
or widths that may
be cast into castparts within the contemplation of this invention.
Figure 31 is an elevation view of a castpart form of which may be produced as
or part of
the casting system disclosed by aspects of this invention. The castpart 480
shown in Figure 31
has an overall length or height 484, and beveled corners on the top portion of
the castpart:are
further shown in detail 32, and the angled edges on the bottom portion are
shown beveled at
angle 479. The straight edge distance 485 on the side of the castpart, and
straight edge
distance 482 on the bottom may be determined based upon the desired resulting
form and
rolling that will later occur on the castpart. Castpart width 481 and beveled
widths 483 and
486 are also illustrated in Figure 31. It will be appreciated by those of
ordinary skill in the art
that aspects of this process may produce symmetrical or asymmetrical castparts
from different
dimensions; for example distance 483 may be different from distance 486.
Figure 32 is detail 32 from Figure 31, and illustrates castpart 480, bevel
width 490,
bevel height 491 with angles 492 and 493 providing the parameters of the
bevel. It will be
appreciated that these parameters may be changed depending upon the other
casting parameters,
the metal composition, the intended rolling to be accomplished on the castpart
480, as well as
by many other factors in the casting or application of the castpart at a later
time, all within the
contemplation of this invention.
Figure 33 is a block flow diagram 500 of one embodiment of a process which may
be
utilized in embodiments of this invention. Figure 33 illustrates the cast
start 501 with an initial
cast speed 502. At some point the cast speed is typically ramped or increased
and a first
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intermediate cast speed 503 may be utilized to produce the desired results,
taper or other feature
of the castpart. Although it may not be necessary, a second intermediate cast
speed ramp 504
may be utilized, and generally a finish cast speed ramp 505 will be utilized
before the end 506
of the casting process. Depending upon the tapering and other goals of the
casting, as well as
other casting parameters, the cast speed may be varied in order to achieve the
desired results.
Figure 34 is an elevation view of another aspect of this invention,
illustrating another
form of an ingot 520 that may be produced as part of this invention. Figure 34
shows tapered
top portion surface 521, sidewall 520a, radius 523 and bottom tapered portion
surface 522. A
significant advantage and feature of aspects of this invention is the ability
to produce any one of
a number of different castpart configurations and forms during the casting
process instead of
through machining or other work after the casting of the castpart. This
feature and advantage
will allow significant savings in the cost and expense of later machining or
manipulating the
solidified castpart, as well as in reheating scrap and waste from the after-
cast process.
It will also be noted that while the embodiments shown in the figures show a
first side, a
second side, a third side and a fourth side, there may be embodiments of this
invention wherein
the sides are configured such that two, three, four or more sides define the
mold framework
with the inner surfaces of said sides defining the mold cavity, all within the
scope of. this
invention.
It will also be appreciated by those of ordinary skill in the art that with
the invention
providing a movable mold wall, other benefits will be received, such as the
ability to correct the
molding process to reduce butt swell and position molds relative to spouts,
and correct mold
clearances. Those of ordinary skill in the art will appreciate that this will
allow the cast to be
done faster and more efficiently. Prior art recognizes the problem with butt
swell and the
advantages that would be realized if the butt swell problem were resolved.
Prior attempts have
tried to increase the casting speed to reduce the butt swell; however aspects
of this invention
allow a resulting parallel profile due to the ability to move the mold walls,
which allows the
castpart to be cast faster with less butt swell or without increased butt
swell.
Embodiments of this invention will also allow the cast speed to be optimized.
The cast
speed in a vertical casting arrangement is the speed at which the bottom block
is lowered into
the casting pit as the molten metal solidifies. There has traditionally been a
tradeoff between
cast speed and castpart quality because while it is desired to cast faster
from a production
standpoint, faster cast speeds generally result in more shrinkage and a
concave outer surface or
rolling surface during steady state casting. If the cast speed is too slow in
a given application,
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an undesirable amount of butt swell tends to result. Embodiments of this
invention may
therefore allow shrinkage to be better managed or controlled to result in a
more desirable
castpart shape while casting at a casting speed that would result in excessive
shrinking but for
the use of this invention. A more desirable castpart shape in some
applications is a castpart
with approximately parallel sides in the middle portion of the castpart, which
generally
provides a more desirable rolling surface. Embodiments of this invention
provide improved
shrinkage management and control in vertical molten metal mold systems.
Embodiments of this invention directed to shrinkage management may include a
method to optimize the rolling surfaces of a castpart produced during
continuous molten metal
casting. In such an embodiment a correlation may be drawn or predicted for a
given
predetermined cast speed for a specific castpart, that shrinkage of a certain
amount at different
locations along the castpart would otherwise occur. This invention then allows
for the relative
movement of the mold walls (or the first side and/or second side) to counter
the shrinkage,
thereby providing a shrinkage control or management system.
Figure 35 is a schematic diagram of an embodiment of a control system 570 that
may be
utilized to control mold side wall movement in practicing aspects of this
invention. Figure 35
illustrates human machine interface ("HMI") 571, programmable logic controller
("PLC") 572
operably connected to and controlled or directed by HMI 571, first motor 575
driven and
controlled by first servo drive 574, which is shown operably connected to and
controlled by
PLC 572, second motor 577 driven and controlled by second servo drive 576,
which is shown
operably connected to and controlled by PLC 572, third motor 579 driven and
controlled by
third servo drive 578, which is shown operably connected to and controlled by
PLC 572, and
fourth motor 581 driven and controlled by fourth servo drive 580, which is
shown operably
connected to and controlled by PLC 572. It will be noted that this is an
exemplary number of
components such as motors, servo drives, PLC and HMI, with no one number being
required to -
practice this invention, nor any particular ration of one group of like
components to another.
Figure 35 further illustrates how each of the motors may be controlling one or
more
molds, with no one particular number of molds controlled being required to
practice this
invention. Figure 35 illustrates first' motor 575 controlling two molds,
second motor 577
controlling one mold, third motor 579 controlling two molds and motor X (which
may
represent the total number of motors) controlling one mold.
Figure 36 is a schematic elevation representation of one configuration 600 of
mold
walls or casting surfaces that may be utilized in some aspects of this
invention, illustrating a top
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casting surface 602b, which may also be referred to as an upper portion of the
casting surface
602b, a middle portion 602a of the casting surface, and a bottom beveled
surface area which is
the bottom portion 602c of the casting surface. Figure 36 illustrates cast
part 327, coolant
stream 605, mold walls 601, spout 321, bevel angle 603 for upper portion 602b
and angle 604
for the bevel in lower portion 602c of the casting surface. The molten metal
level is shown in
the middle portion 602a of the casting surface.
Figures 37A through 37E show a number of different configurations, angles and
other
geometries for the upper, middle and lower portions of the casting surface on
mold walls to
show various applications of embodiments of this invention. It will be
appreciated that no one
particular configuration is required to practice the invention, but that any
one of a number of
different configurations may be utilized to optimize different embodiments
based on different
casting parameters.
Figure 37A is a schematic elevation representation of one configuration 610 of
mold
walls 611 with or casting surfaces that may be utilized in some aspects of
this invention.
Figure 37A illustrates such a configuration which includes two top casting
surface areas 612a
and 612b, two bottom casting surface areas 612d and 612e, and middle portion
612c of casting
surface, for each mold wall 611. The first top casting surface area 612a is at
angle 614 to the
vertical, the second top casting surface area 612b is at angle 613 to the
vertical, first bottom
casting surface area 612e is at angle 614 to the political and second bottom
casting surface area
612d is at angle 613 to vertical. Figure 37A also shows cast part 327, spout
321, and mold
walls 611.
Figure 37B is a schematic elevation representation of one configuration 700 of
mold
walls 731 with casting surfaces that may be utilized in some aspects of this
invention,
illustrating a top portion and a bottom portion that include both a linear
casting surface 731 b
and a curved or arcuate casting surface 731 c, a middle portion 731 a of the
casting surface and a
lower portion of the casting surface which includes linear casting surface 731
d and arcuate
casting surface 731e. Figure 37B also shows cast part 327, spout 321, and mold
walls 731.
Figure 37C is a schematic elevation representation of one configuration 740 of
mold
walls 741 with casting surfaces that may be utilized in some aspects of this
invention,
illustrating a top casting surface portion 742b, a bottom curved or arcuate
casting surface
portion 742c, and a middle casting surface portion 742a. Figure 37C also shows
cast part 327,
spout 321, and mold walls 741.
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Figure 37D is a schematic elevation representation of one configuration 750 of
mold
walls 751 with casting surfaces that may be utilized in some aspects of this
invention. Figure
37D illustrates a top casting surface area 752b at angle 753 from vertical or
from the middle
casting surface area in this case because it is linear, a middle casting
surface area 752a, and a
bottom casting surface area 752c at angle 755 from vertical. In Figure 37D,
angle 753 is
different than angle 755, and the length 754 of the beveled area at the top
portion is different
than the length 756 at the bottom portion of the beveled area. It should be
noted that the desired
cast part may be preferably configured using different configurations for the
casting surface,
and dissimilar configurations in angles and lengths from the top portion of
the casting surface
to the bottom portion of the casting surface, all within the contemplation of
some aspects of this
invention. Figure 37D also shows cast part 327, spout 321, and mold walls 751.
Figure 37E is a schematic elevation representation of one configuration 760 of
mold
walls 761 with casting surfaces that may be utilized in some aspects of this
invention,
illustrating a combination casting surface which includes a middle portion
162a, a top portion
762b at an angle 763 from vertical, a curved or arcuate bottom portion 762c
with an inner
radius 764. Figure 37E also shows cast part 327, spout 321, and mold walls
761.
Figures 38A through 38D are a series of schematic elevation representations of
one
configuration 620 of mold walls 621 with casting surfaces, and sequentially
illustrate one
method wherein embodiments of this invention may be utilized in casting, with
particular
reference to the molten metal level and casting surface relative to the molten
metal level during
the casting process. The casting surfaces illustrated in Figures 38A through
38D include
middle portion 623a, top portion 623b at angle 625 from vertical, bottom
portion 623c at angle
626 from vertical, cast part 327, molten metal spout 321. Figures 38A through
38D further
illustrate an aspect of this invention wherein the mold walls 621, or more
particularly, the
casting surface, maybe moved vertically upward or downward in order to more
effectively
manage the level of molten metal relative to the casting surface and the
portion of the casting
surface where it is desired at that stage of casting to have the molten metal
level. In order to
avoid repetitious Lee restating each component relative to each of Figures 38A
through 38D,
they will each not be repeated for each figure. Arrow 622 show the vertical
movement of the
mold walls 621 which causes the vertical movement of the casting surfaces, and
arrows 622a
shows how the casting surfaces or mold walls 621 may be moved horizontally
relative to the
castpart.
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Figure 38A therefore illustrates a molten metal level in the middle portion
623a of the
casting surface during the initial or startup phase when the starting block is
filling and still at
least partially located at 20 and the casting surfaces.
Figure 38B therefore illustrates a molten metal level at the top portion 623b
of the
casting surface during the next phase wherein the bottom portion of the cast
part is being
formed outwardly from the dimension shown in Figure 38B. Even though it may be
stated
here in that the molten metal level is raised, this is relative and relative
to the casting service so
that. the molten metal level may be raised or it might rise relative to the
casting surface if the
mold walls 621 are moved upwardly and/or downwardly to accomplish the relative
movement.
Figure 38C therefore illustrates a molten metal level back in the middle
portion 623a of
the casting surface, which is a preferred location during the middle of the
casting when it is
referred to as steady state casting.
Figure 38D therefore illustrates a molten metal level at the lower portion
623c of the
casting surface during the final phase wherein the top portion of the cast
part 327 is being
configured as desired, such as placing a taper very in at the same approximate
angle 626 that
lower portion 623c is configured at. It is important that the molten metal
level remained below
the point at which the middle portion 623a of the casting surface intersects
the lower portion
623c of the casting surface. This is a preferred location for the molten metal
level during the
last phase of casting to achieve a tapered top in the castpart 327. The angle
of the resulting
taper in the cast part will be approximately equal to angle 626, with
allowances for tolerances
and shrinkages.
Figure 39 is a schematic elevation representation of one configuration 640 of
mold
walls 641 with casting surfaces in one embodiment of the invention,
illustrating a casting
surface with a top portion 642b, a middle portion 642a, and a bottom portion
642c at angle 648
from vertical. Figure 39 illustrates cast part 327 being formed at its top
portion with a taper at a
predetermined angle 648. Figure 39 further illustrates molten metal spout 321,
solidification
point 647, coolant 644, molten metal surface 645.
Figure 40 is a schematic elevation representation of one configuration 620 of
mold
walls with middle portion 642a and lower portion 642c of casting surfaces in
one embodiment
of the invention. Figure 40 illustrates how mold walls may be moved
horizontally as
represented by arrow 651. The solidification points 647 shows where
solidification is
occurring and there is a freeze area 650 which will generally happen if the
molten metal level
645 is not below the corner between the two casting surfaces shown at or near
solidification
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WO 2009/025874 PCT/US2008/010086
point 647. If the solidification occurs as freeze 650, then the mold walls and
casting surface
may not be moved further inwardly because the solidified metal 650 or freeze,
would prevent
the inward movement of mold walls or casting surface 642a. That is why in most
embodiments of this invention during that phase of the casting, it is
preferred to maintain the
molten metal leve1645 at or below the solidification point 647.
Figure 41 is a schematic elevation representation of a configuration 660 of
mold walls
641 or casting surfaces in one embodiment of the invention, illustrating
casting surfaces
including an upper portion 642c, which may be referred to as a beveled
surface, forming a
tapered castpart bottom portion 655 in combination with the bottom block 657.
In this phase of
the casting, mobile metal is deposited through spout 321 and molten metal
level 645 is
maintained on upper portion 642c, which is at angle 654 from vertical. Figure
41 shows how a
bottom portion of a cast part may be formed in combination by the inner cavity
configuration of
a bottom block 657 combined with aspects of this invention provided by movable
casting
surfaces and an angled casting surface for preferred results.
Figure 42 is a schematic elevation representation of a mold and bottom block
configuration 350 which illustrates another feature of some embodiments of
this invention,
wherein the mold walls 357 can be moved outwardly to accommodate the expansion
of.: the
bottom block 354 on startup. It is desirable to have a tight fit between
bottom block 354 and
mold walls 356 and 357. However since prior art mold walls are not movable to
accommodate
the natural expansion of the metallic bottom block 354, it would be difficult
to maintainr the
desired tolerances between mold walls 356 and 357, and the bottom block sides
354, which
would likely leave the mold sham because the bottom block 354 might become
enlarged and
stuck within the mold cavity between mold walls 356-1357. Second bottom block
identification 354 be in 354 CE show the bottom block in its expanded
condition from the heat,
and arrows 358 and 359 show how mold walls 356 and 357 can be moved so that
the same tight
fit remains between the mold walls and the bottom block, but the bottom block
is met expand
sets that get stuck tween the mold walls. In this case the bottom block height
355 is measured
from the bottom surface 354a and the top of bottom block walls 354b and 354c.
Arrows 358a
and 358b show how mold walls 356 in 357 may be moved vertically.
As will be appreciated by those of reasonable skill in the art, there are
numerous
embodiments to this invention, and variations of elements and components which
may be used,
all within the scope of this invention.
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One embodiment of this invention, for example, a molten metal mold is provided
which
comprises: a mold cavity framework including a first side, a second side
opposite the first
side, a third side, and a fourth side opposite the third side, each side
including an inner surface
and the inner surfaces defining a mold cavity; and wherein the first side is
movably mounted
relative to the second side.
Further embodiments from that disclosed in the preceding paragraph may
include: a
molten metal mold further wherein the second side is movably mounted relative
to the first
side; a molten metal mold further wherein the first side moves linearly
relative to the second
side; a molten metal mold further wherein the first side is pivotally mounted;
and/or a molten
metal mold further wherein pivotal movement of the first side relative to the
mold cavity
framework alters the defined mold cavity. In further aspects, the movement of
the first side
and the second side may be asynchronous.
In another embodiment, a vertical molten metal mold casting system may be
provided
which comprises: a mold cavity framework including a first side, a second side
opposite the
first side, a third side, and a fourth side opposite the third side, each side
including an inner
surface and wherein the inner surfaces define a mold cavity; wherein the first
side and second
side are movably mounted relative to one another; and a bottom block
configured to fit within
the mold cavity at startup of the mold casting system.
Further embodiments from that disclosed in the preceding paragraph may
include: a
vertical molten metal mold casting system further wherein the first side and
second side move
linearly relative to one another; a vertical molten metal mold casting system
further wherein
the first side and second side are pivotally mounted for movement relative to
one another; a
vertical molten metal mold casting system wherein the bottom block includes
two sidewalls and
further wherein the third side and the fourth side of the mold cavity
framework combined with
the two sidewalls of the bottom block to define the mold cavity on startup; a
vertical molten
metal mold casting system wherein the bottom block includes an internal
cooling apparatus;
and/or a vertical molten metal mold casting system further wherein the bottom
block is
configured for vertical movement within the mold cavity during startup to
control a spout to
bottom block distance during startup casting.
In another embodiment of the invention, a method for vertical direct chill
molten metal
casting is provided comprising: providing a mold cavity framework with a first
side and a
second side opposite the first side, a third side and a fourth side opposite
the third side, with
inner surfaces of the first side, second side, third side and fourth side
defining a mold cavity
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disposed to receive molten metal; providing a vertically movable bottom block
configured
relative to the mold cavity to contain molten metal entering the mold cavity
upon startup;
providing molten metal to the mold cavity; moving the bottom block downward at
a
predetermined rate; and moving the first side and the second side of the mold
cavity framework
relative to one another during casting and thereby varying dimensions of a
resulting castpart
during casting.
Further embodiments from that disclosed in the preceding paragraph may
include: a
method for vertical direct chill molten metal casting, and further wherein the
first side and
second side are moved linearly relative to one another; a method for vertical
direct chill molten
metal casting, and further wherein the first side and second side are moved
asymmetrically
relative to one another; a method for vertical direct chill molten metal
casting, and further
wherein the first side and the second side are pivotally mounted relative to
the mold cavity
framework such that pivotal movement of the first side and the second side
alter the defined
mold cavity; and/or a method for vertical direct chill molten metal casting,
and further wherein
the moving of the first side and the second side are at the same approximate
rate.
Still further embodiments of that disclosed in the second preceding paragraph
may
include: a method for vertical direct chill molten metal casting and further
wherein moving the
first side and the second side of the mold cavity framework relative to one
another during
casting further comprises moving the first side and the second side away from
each other at an
early portion of the casting after startup, to provide an increasing cross-
section of the castpart
from its bottom portion; and/or a method for vertical direct chill molten
metal casting wherein
moving the first side and the second side of the mold cavity framework
relative to one another
during casting further comprises: moving the first side and the second side
toward one another
at an end portion of the casting to provide a decreasing cross-section of the
castpart at its top
portion. These embodiments may be further wherein moving the first side and
the second side
of the mold cavity framework relative to one another during casting further
comprises:
moving the first side and the second side toward one another at an end portion
of the casting to
provide a decreasing cross-section of the castpart at its top portion. The
increasing
cross-section of the castpart from its bottom portion provides a taper on the
bottom portion of
the castpart may for example be at an angle in the range of 22 degrees to 29
degrees; and/or the
increasing cross-section of the castpart from its top portion provides a taper
on the top portion
of the castpart may be at an angle in the range of 22 degrees to 29 degrees.
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In further method embodiments of method for vertical direct chill molten metal
casting
as set forth above, the moving of the first side and the second side of the
mold cavity
framework relative to one another during casting produces a castpart with a
larger cross-section
in a middle portion than the bottom block; and/or produces a castpart with a
larger cross-section
in its middle portion than at its bottom portion and top portion.
In yet another embodiment of the invention, a molten metal mold is provided
which
comprises: a mold cavity framework including a first side, a second side
opposite the first side
and spaced apart from the first side by a variable distance, a third side, and
a fourth side
opposite the third side, each side including an inner surface and the inner
surfaces defining a
mold cavity; and wherein the mold cavity framework is alternatively
configurable to cast a first
castpart with a first thickness and to cast a second castpart with a second
thickness.
In still another embodiment of the invention, a method for vertical direct
chill molten
metal casting comprising: providing a mold cavity framework with a first side
and a second
side opposite the first side and spaced apart from the first side by a
variable distance, a third
side and a fourth side opposite the third side, with inner surfaces of the
first side, second side,
third side and fourth side defining a mold cavity disposed to receive molten
metal; providing a
vertically movable bottom block configured relative to the mold cavity to
contain molten metal
entering the mold cavity upon startup; providing molten metal to the mold
cavity; casting a
first castpart of a first thickness; and moving the first side and the second
side of the mold
cavity framework relative to one another; and casting a second castpart of a
second thickness
different than the first thickness.
In a still further embodiment of the invention, a molten metal mold may be
provided
which comprises: a mold framework; a mold operative connected to the mold
framework, the
mold being comprised of: a first side movably mounted relative to the mold
framework; a
second side opposite the first side and movably mounted to the mold framework;
a third side; a
fourth side opposite the third side; wherein each side includes an inner
surface and the inner
surfaces define a mold cavity; a first motor operatively connected to the
first side and
configured to move the first side relative to the mold framework; a second
motor operatively
connected to the second side and configured to move the second side relative
to the mold
framework; and a programmable logic controller operatively connected to and
controlling the
first motor and the second motor to control predetermined movement of the
first side and the
second side of the mold.
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Further embodiments "from that disclosed in the preceding paragraph may
include: a
molten metal mold and further wherein the first motor and the second motor are
servo motors;
and/or a molten metal mold further comprising a human user interface
operatively attached to
the programmable logic controller.
In another method embodiment, a method to optimize the rolling surfaces of a
castpart
produced during continuous molten metal casting may be provided which
comprises:
providing a mold cavity framework with a first side and a second side opposite
the first side, a
third side and a fourth side opposite the third side, with inner surfaces of
the first side, second
side, third side and fourth side defining a mold cavity disposed to receive
molten metal;
providing a vertically movable bottom block configured relative to the mold
cavity to contain
molten metal entering the mold cavity upon startup; providing molten metal to
the mold
cavity; moving the bottom block downward at a predetermined cast speed; and
moving the
first side and the second side of the mold cavity framework in a predetermined
way relative to
one another during casting to optimize the castpart configuration for later
operations. A
possible further embodiment of this may be wherein moving the first side and
the second side
of the mold cavity is to at least substantially offset predicted shrinkage
during casting at the
predetermined cast speed.
In compliance with the statute, the invention has been described in language
more or
less specific as to structural and methodical features. It is to be
understood, however, that the
invention is not limited to the specific features shown and described, since
the means herein
disclosed comprise preferred forms of putting the invention into effect. The
invention is,
therefore, claimed in any of its forms or modifications within the proper
scope of the appended
claims appropriately interpreted in accordance with the doctrine of
equivalents.
34
