U.S. patent number 3,672,436 [Application Number 04/877,542] was granted by the patent office on 1972-06-27 for vibrating wall continuous casting mold.
This patent grant is currently assigned to Interlake Steel Corporation. Invention is credited to Emil Simich, Alvin L. Winkler, James N. Wognum.
United States Patent |
3,672,436 |
Wognum , et al. |
June 27, 1972 |
VIBRATING WALL CONTINUOUS CASTING MOLD
Abstract
Apparatus for continuous casting of metal having a cavity formed
by a plurality of flexible mold sections which minimize the
problems of mold warpage by thermal expansion. Resilient backup for
the mold sections for controlling mold cavity contour, improved
mold section operating means and arrangement therefor is also
provided.
Inventors: |
Wognum; James N. (Chicago,
IL), Simich; Emil (Chicago, IL), Winkler; Alvin L.
(Chicago, IL) |
Assignee: |
Interlake Steel Corporation
(Chicago, IL)
|
Family
ID: |
25370195 |
Appl.
No.: |
04/877,542 |
Filed: |
November 28, 1969 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
643562 |
Jun 5, 1967 |
3528487 |
Sep 15, 1970 |
|
|
Current U.S.
Class: |
164/416; 164/451;
164/491; 164/478 |
Current CPC
Class: |
B22D
11/0535 (20130101) |
Current International
Class: |
B22D
11/053 (20060101); B22d 011/00 (); B22d
027/08 () |
Field of
Search: |
;164/4,82,83,260,261,280,283,154,150 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Annear; R. Spencer
Parent Case Text
This application is a division of application, Ser. No. 643,562,
filed June 5, 1967, now U.S. Pat. No. 3,528,487, issued Sept. 15,
1970.
Claims
We claim:
1. Apparatus for continuous casting of metal of a type having a
cavity extending longitudinally therethrough open at its ends and
formed by the inside surfaces of a plurality of mold sections
located around the cavity with said inside surfaces disposed
substantially parallel to the longitudinal axis of the cavity, one
of said open ends of said cavity being a receiving end through
which molten metal can be introduced into said cavity and the other
of said open ends of said cavity being a discharge end through
which said metal can be progressively discharged from said cavity,
vibrating means connected to vibrate said mold sections to cause a
plurality of opposed surfaces of said inside surfaces of said
sections to vibrate in closed loop paths, the first portion of
movement involving moving each of said opposed inside surfaces of
the sections toward said longitudinal axis of said cavity and
forward toward the discharge end thereof to provide a driving force
on the metal casting to propel it through the cavity, the second
portion of movement involving moving each of said opposed inside
surfaces in retraction away from said longitudinal axis and in
return movement toward the receiving end of said cavity while said
metal is in said cavity so that resistance to the forward movement
of the metal by the inside surfaces of the sections is minimized,
corner sections mounted with respect to relatively rigid and
inflexible support means to contact and bridge between adjacent
edges of the inside surfaces of the mold sections, the inside
surfaces of the mold sections and the corner sections thereby
collectively providing a substantially closed inside wall of the
cavity, said corner sections having sufficiently small beam
strength that they are relatively flexible when stressed
transversely as a beam as compared to the relatively inflexible and
rigid support means with respect to which the mold sections are
mounted.
2. Apparatus as defined by claim 1 characterized by flexible corner
section mounting means located in rigid frame means for supporting
said corner sections in their locations around the cavity, and
resilient backup means applying a backup force reacting between the
mounting means and the corner sections for overcoming the tendency
of the corner sections to deform from thermal stresses within the
corner sections when subjected to the heat of the metal passing
through the cavity during the casting period.
3. Apparatus as defined by claim 2 characterized by, said resilient
backup means being in the form of an inflatable tube which provides
the backup force upon inflation of the tube with fluid under
pressure, and means for inflating the tube with fluid under
pressure.
4. Apparatus for continuous casting of metal of a type having a
cavity extending longitudinally therethrough open at its ends and
formed by the inside surfaces of a plurality of mold sections
located around the cavity with said inside surfaces disposed
substantially parallel to the longitudinal axis of the cavity, one
of said open ends of said cavity being a receiving end through
which molten metal can be introduced into said cavity and the other
of said open ends of said cavity being a discharge end through
which said metal can be progressively discharged from said cavity,
vibrating means connected to vibrate said mold sections to cause a
plurality of opposed surfaces of said inside surfaces of said
sections to vibrate in closed loop paths, the first portion of
movement involving moving each of said opposed inside surfaces of
the sections toward said longitudinal axis of said cavity and
forward toward the discharge end thereof to provide a driving force
on the metal casting to propel it through the cavity, the second
portion of movement involving moving each of said opposed inside
surfaces in retraction away from said longitudinal axis and in
return movement toward the receiving end of said cavity while said
metal is in said cavity so that resistance to the forward movement
of the metal by the inside surfaces of the sections is minimized,
independent mold section mounting means for each of said mold
sections, said vibrating means have a first linkage drive means for
driving each mold section mounting means to cause the mold section
attached to it to move through its vibrating motion, said first
linkage drive means for each mold section being contained within a
separate linkage enclosure, each mold section mounting means being
in the form of a shell at least partially surrounding the linkage
enclosure, said linkage enclosure having connecting means
projecting outwardly from it engaging the mold section mounting
means to provide the driving connection for the mold section
mounting means, and a second drive means connected to drive the
first linkage drive means contained in the linkage enclosure for
driving the mold section mounting means.
5. Apparatus for continuous casting of metal of a type having a
cavity extending longitudinally therethrough open at its ends and
formed by the inside surfaces of a plurality of mold sections
located around the cavity with said inside surfaces disposed
substantially parallel to the longitudinal axis of the cavity, one
of said open ends of said cavity being a receiving end through
which molten metal can be introduced into said cavity and the other
of said open ends of said cavity being a discharge end through
which said metal can be progressively discharged from said cavity,
said mold sections having hollowed cavities for at least portions
of their lengths through which coolant fluid can flow, each of said
mold sections having an inlet passage and an outlet passage for its
hollowed cavity, and means for providing fluid-tight connections at
the inlet passage and the outlet passage, at least one of said
connections being provided by means of a tubular plunger biased by
a spring means to urge the plunger tightly around the passage of
the mold section, said tubular plunger being provided in a fluid
passage leading to a source of coolant fluid which is used as the
supply of coolant fluid for circulation through the mold
sections.
6. Apparatus for continuous casting of metal of a type having a
cavity extending longitudinally therethrough open at its ends and
formed by the inside surfaces of a plurality of mold sections
located around the cavity with said inside surfaces disposed
substantially parallel to the longitudinal axis of the cavity, one
of said open ends of said cavity being a receiving end through
which molten metal can be introduced into said cavity and the other
of said open ends of said cavity being a discharge end through
which said metal can be progressively discharged from said cavity,
vibrating means connected to vibrate said mold sections to cause a
plurality of opposed surfaces of said inside surfaces of said
sections to vibrate in closed loop paths, the first portion of
movement involving moving each of said opposed inside surfaces of
the sections toward said longitudinal axis of said cavity and
forward toward the discharge end thereof to provide a driving force
on the metal casting to propel it through it through the cavity,
the second portion of movement involving moving each of said
opposed inside surfaces in retraction away from said longitudinal
axis and in return movement toward the receiving end of said cavity
while said metal is in said cavity so that resistance to the
forward movement of the metal by the inside surfaces of the
sections is minimized, corner sections mounted with respect to
relatively rigid and inflexible support means to contact and bridge
between adjacent edges of the inside surfaces of the mold sections,
the inside surfaces of the mold sections and the corner sections
thereby collectively providing a substantially closed inside wall
of the cavity, said corner sections having sufficiently small beam
strength that they are relatively flexible when stressed
transversely as a beam as compared to the relatively inflexible and
rigid support means with respect to which the mold sections are
mounted, flexible corner section mounting means located in rigid
frame means for supporting said corner sections in their locations
around the cavity, and resilient backup means applying a backup
force reacting between the mounting means and the corner sections
sufficient to cause the corner sections to flex and remain in
intimate contact against the mold sections to cause the corner
sections to conform to dimensional irregularities in the mold
sections and the corner sections.
7. Apparatus for continuous casting of metal of a type having a
cavity extending longitudinally therethrough open at its ends and
formed by the inside surfaces of a plurality of mold sections
located around the cavity with said inside surfaces disposed
substantially parallel to the longitudinal axis of the cavity, one
of said open ends of said cavity being a receiving end through
which molten metal can be introduced into said cavity and the other
of said open ends of said cavity being a discharge end through
which said metal can be progressively discharged from said cavity,
vibrating means connected to vibrate said mold sections to cause a
plurality of opposed surfaces of said inside surfaces of said
sections to vibrate in closed loop paths, the first portion of
movement involving moving each of said opposed inside surfaces of
the sections toward said longitudinal axis of said cavity and
forward toward the discharge end thereof to provide a driving force
on the metal casting to propel it through the cavity, the second
portion of movement involving moving each of said opposed inside
surfaces in retraction away from said longitudinal axis and in
return movement toward the receiving end of said cavity while said
metal is in said cavity so that resistance to the forward movement
of the metal by the inside surfaces of the sections is minimized,
independent mold section mounting means for each of said mold
sections, said vibrating means having a first drive means for
driving each mold section mounting means to cause the mold section
attached to it to move through its vibrating motion, said first
drive means for each mold section being contained within a separate
enclosure, each mold section mounting means being in the form of a
shell at least partially surrounding the enclosure, said enclosure
having connecting means projecting outwardly from it from the first
drive means and engaging the mold section mounting means to provide
the driving connection for the mold section mounting means, and a
second drive means connected to drive the first drive means
contained in the enclosure for driving the mold section mounting
means.
8. Apparatus for continuous casting of metal of a type having a
cavity extending longitudinally therethrough open at its ends and
formed by the inside surfaces of a plurality of mold sections
located around the cavity with said inside surfaces disposed
substantially parallel to the longitudinal axis of the cavity, one
of said open ends of said cavity being a receiving end through
which molten metal can be introduced into said cavity and the other
of said open ends of said cavity being a discharge end through
which said metal can be progressively discharged from said cavity,
vibrating means connected to vibrate said mold sections to cause a
plurality of opposed surfaces of said inside surfaces of said
sections to vibrate in closed loop paths, the first portion of
movement involving moving each of said opposed inside surfaces of
the sections toward said longitudinal axis of said cavity and
forward toward the discharge end thereof to provide a driving force
on the metal casting to propel it through the cavity, the second
portion of movement involving moving each of said opposed inside
surfaces in retraction away from said longitudinal axis and in
return movement toward the receiving end of said cavity while said
metal is in said cavity so that resistance to the forward movement
of the metal by the inside surfaces of the sections is minimized,
independent mold section mounting means for each of said mold
sections, a portion of said vibrating means being provided for
vibrating each mold section mounting means separate from the
others, each said portion being contained within a separate
enclosure, the mold section mounting means for each mold section
being in the form of a shell at least partially surrounding a
respective enclosure, each of said portions of the vibrating means
projecting outwardly of its respective enclosure and connected to
drive the mold section mounting means at least partially
surrounding it.
9. Apparatus as defined by claim 8 characterized by, the enclosure
for each mold section mounting means being substantially dust
tight.
10. Apparatus as defined by claim 4 characterized by, said first
linkage drive means having a main driven link eccentrically driven
from said second drive means, the main driven link being connected
to drive one end of a mold section support means and a second link,
the second link being journalled to drive the other end of the mold
section support means.
11. Apparatus as defined by claim 10 characterized by, an
additional linkage mechanism mounted between the main driven link
and the enclosure and between the second link and the enclosure for
limiting the movement of the mold section support means, said
additional linkage being journalled to the enclosure by means
adjustable for varying the radial position of the mold section
support means relative to the longitudinal axis of the mold
cavity.
12. Apparatus for continuous casting of metal of a type having a
cavity extending longitudinally therethrough open at its ends and
formed by the inside surfaces of a plurality of mold sections
located around the cavity with said inside surfaces disposed
substantially parallel to the longitudinal axis of the cavity, one
of said open ends of said cavity being a receiving end through
which molten metal can be introduced into said cavity and the other
of said open ends of said cavity being a discharge end through
which said metal can be progressively discharged from said cavity,
vibrating means connected to vibrate said mold sections to cause a
plurality of opposed surfaces of said inside surfaces of said
sections to vibrate in closed loop paths, the first portion of
movement involving moving each of said opposed inside surfaces of
the sections toward said longitudinal axis of said cavity and
forward toward the discharge end thereof to provide a driving force
on the metal casting to propel it through the cavity, the second
portion of movement involving moving each of said opposed inside
surfaces in retraction away from said longitudinal axis and in
return movement toward the receiving end of said cavity while said
metal is in said cavity so that resistance to the forward movement
of the metal by the inside surfaces of the sections is minimized,
corner sections mounted to contact and bridge between adjacent
edges of the inside surfaces of the mold sections, the inside
surfaces of the mold sections and the corner sections thereby
collectively providing a substantially closed inside wall of the
cavity, corner section mounting means mounting said corner sections
unrestrained in their longitudinal direction to permit their free
longitudinal extension and contraction when the corner sections are
subjected to the heat of the metal being cast through the cavity.
Description
This invention relates to the art of continuous casting and
particularly relates to improvements in continuous casting in a
machine of the vibrating mold type as, for example, shown in U.S.
Pat. No. 3,075,264 in the name of James N. Wognum.
The type of continuous casting machine is one having a cavity
extending longitudinally through it, the cavity being open at its
opposite ends and formed by the inside surfaces of a plurality of
vibrating mold sections located around the cavity, one of the open
ends of the cavity being the receiving end through which molten
metal can be introduced into the cavity and the other end being for
discharge of the metal after it is solidified as a casting as it
passes through the cavity. The mold sections may be vibrated in
closed orbital paths to drive the casting being formed in the
cavity through the cavity.
One of the problems associated with the operation of this type of
continuous casting machine is created by thermal expansion of the
mold sections which creates an undesirable warping of the mold
sections which, if permitted, can bind the machine and make it
inoperative. Previously, solution of this problem has been sought
by employing larger masses of metal for the mold sections to
counteract the warpage by reliance on the strength of the extra
metal. Experience shows that objectionable differentials in
expansion of different parts of the mold sections due to the
various temperature differentials is not arrested by the use of the
added metal. Instead, applicant has discovered far more can be
accomplished by the use of flexible and resilient mold sections of
relatively small cross section and of minimal metal mass. By the
use of flexible mold sections, application has found that the mold
sections can be retained in their proper shape without warpage,
even though thermal stresses are present. Therefore, it is the
principal object of this invention to provide an improved
continuous casting machine employing flexible mold sections of
relatively small mass which, although subject to thermal stresses
due to temperature differentials, can be easily retained in a
proper configuration without objectionable warpage.
In order to accomplish the aforesaid object, it is another object
of the invention to provide resilient backing means for each mold
section which can be used to apply forces along the mold sections
to keep them in their proper configuration when subject to the
tendency for warpage due to the thermal stresses.
This can be accomplished by employing resilient means, such as
springs, or by means of inflatable cushions, as another example,
and in other ways.
One of the current problems with continuous casting machines, also
involving thermal considerations, is that there is a tendency for
the casting to shrink away from the internal side walls of the mold
as the casting solidifies. The result is that the casting portions
out of contact with the mold are difficult to cool properly. For
this reason, even though coolant is circulated through openings in
the mold itself, the lack of contact between the casting and the
mold reduces the conduction of heat from the casting to the mold
where the heat can be removed by the coolant. In fact, this
separation of the casting from the mold leaves an air or gas space
which is a poor conductor of heat which acts more like a heat
insulator. For this reason, it is common to employ water spray
cooling on the portions of the casting exiting from the mold. Water
spray cooling is in some instances objectionable because it does
not permit the casting to be transported directly from the mold
into a controlled atmosphere for purposes of retaining a bright
finish on the surface of the casting. In order to overcome this
problem, it is another object of this invention to provide a mold
having flexible mold sections which can be insured of contacting
the external wall surfaces of the casting so that efficient
transfer of heat can be effected from the casting through the
internal walls of the mold and to the coolant circulating through
the mold without necessarily requiring additional external cooling,
as by water spray cooling, for example.
Especially when casting high alloy metals, it is desirable to
employ molds of long length in order to insure that sufficient wall
portions of the casting freeze thick enough so that the casting
skin does not break and allow hot metal from the core of the
casting to pour out through it which is a dangerous condition and
one which causes a poor surface condition. With high alloy metals,
the freezing range of the metal is very wide and this is the reason
why more mold time is desired. However, in other molds, as the
casting cools, it shrinks away from the mold wall surface and the
cooling by lack of contact with the mold sections becomes
inefficient. In fact, it seems that the mold for cooling purposes,
should be no longer than the length which remains in contact with
the casting. Thereafter, since the mold is very ineffective for
cooling by conduction, it is desirable to employ a water spray
directed onto the casting emerging from the mold section. But, this
suggests shortening the mold when the high alloy material indicates
the opposite requirement that the mold should be longer. Due to the
increased assurance of proper cooling in the mold for its entire
length because of the improvements of this invention, it is another
object of the invention to provide an improved mold which can be
made in longer lengths to accommodate those situations requiring
the longer lengths.
Another object of the invention is to provide flexible mold
sections which are connected only at one end to the mold section
support structure. This permits the mold sections to freely
lengthen and shorten longitudinally as heating and cooling occur.
This further minimizes the stresses due to temperature
differentials causing thermal expansion and contraction.
In order to maintain high heat transfer through the mold sections
along their lengths, efforts have been made to provide special
contours for the mold walls according to the expected thermal
shrinkage of the casting as it progresses through the mold.
However, this has been relatively unsuccessful because different
contours are required for each different metal used because the
different metals expand or contract by different amounts when
subject to the same temperature differentials. Further, if
advancement speed of the castings through the mold varies, each
different speed suggests that a different contour be required. It
is an object of this invention to provide a flexible mold section
so that the mold can be employed with many different metals of
different physical thermal properties and be operated at many
different speeds without requiring any special predetermined
contouring of the mold sections to overcome difficulties created by
uneven thermal expansion and contract and which can be adjusted
while operating to cause the mold sections to deflect into proper
contours according to the actual shrinkage contours of the
castings.
It is another object of the invention to provide an improved
modular type of construction for a continuous casting machine
involving a casting unit module having all of the basic casting
components contained within it which lends itself to ready
insertion or removal in a continuous casting system and which has
its major moving parts housed in dust-proof enclosures.
It is another object of the invention to provide a modular
continuous casting machine having an improved radial construction
readily permitting basic components to be employed for changeover
to cast different sizes of cross section of castings.
It is another object of the invention to provide a continuous
casting machine which can be assembled and disassembled readily for
easy access to all parts of it.
It is still another object of the invention to provide such a
machine which has an improved driving arrangement for causing the
mold sections to vibrate through their orbital paths, including
suitable vernier adjustment means for fine adjustment of the
spacing of the mold sections relative to each other.
It is another object of the invention to provide improved linkage
mechanism in the driving means for the mold sections, which linkage
provides the desirable vibratory paths for the mold sections.
It is also another object of the invention to provide a resilient
takeup for any play existing between the operating shafts and the
bearings supporting them so that the linkage mechanisms employed
are without looseness, even though there are no precision fits at
the bearing connections.
Because it is desirable to have the individual mold sections fluid
cooled by passing the coolant through bores extending internally
through the mold sections and to have the mold sections easily
removable from the casting machine assembly, it is necessary to
have quick disconnects between the fluid coolant inlets and outlets
to the mold sections. It is an object of this invention to provide
improved disconnects which either automatically connect or
disconnect the fluid coolant outlets and inlets or which can be
operatively connected or disconnected to the mold sections. The
means for accomplishing this can be by use of a connecting tubular
piston which abuts against the mold section by means of spring
pressure to close the connection or by means of fluid pressure.
It is a further object of the invention to provide improved corner
inserts mounted between adjacent mold sections for the purpose of
minimizing leakage of liquid metal from the casting at the corners
of the mold while the casting is propelled through the mold. These
improved corner inserts are made flexible and provided with
relatively flexible backings which may be further backed by
resilient members urging the corner inserts into intimate contact
against the mold sections and thereby seal the flow of liquid metal
from between the interfaces adjacent mold sections and corner
inserts to follow the changeable contours of the flexible mold
sections.
It is another object of the invention to provide certain proximity
device behind each mold section for the purpose of indicating
externally of the mold that the contacting mold surfaces are in
complete contact with the casting surfaces. These proximity or
sensing devices provide signals for detecting and indicating this
information while the mold is in operation. This is important
because it is necessary for accuracy that the mold sections be
adjusted dynamically during the casting operation so that the mold
sections are accurately relocated to the changing sizes of the
shrinking or expanding portions of the moving casting while the
casting is being progressively cooled.
It is another object of this invention to provide a continuous
casting machine of the type described which has adjustable means at
both the upper and lower ends of each mold section to allow for
radial adjustment of either of the mold sections as required. This
allows the lower ends of the mold sections to be radially shifted
relative to the upper ends of the mold sections in order to
compensate for the shrinkage of the casting as it solidifies.
It is another object of the invention to provide retainer blocks
for the mold sections which are relatively rigid and made of
material with relatively low susceptibility to thermal warpage at
the operating temperatures of the machine. This provides relatively
rigid backup means for the mold sections even though the mold
sections themselves are flexible. It is important that the backup
means for the mold sections be rigid in order to provide
dimensional stability to the apparatus.
Other objects and advantages of the invention should become
apparent upon reference to the accompanying drawings in which:
FIG. 1 shows a preferred embodiment of continuous casting machine
made according to the invention in the form of a modular unit;
FIG. 1a shows a cross-sectional view of a spring retaining means
employed with the unit of FIG. 1;
FIG. 2 shows a horizontal cross section of the major functional
parts of the mold portion of the preferred embodiment of the
continuous casting machine shown in FIG. 1;
FIG. 3 shows a perspective view, primarily from the rear, of a mold
section support and the mold section it supports;
FIG. 4 shows a perspective view, primarily of the front portion of
the apparatus shown in FIG. 3;
FIG. 5 shows a perspective exploded, partially cutaway and partial
sectional view of a mold section and its related components
separate from its support indicated in FIGS. 3 and 4;
FIG. 5a shows a cutaway sectional view of an alternate construction
of mold section to that shown in FIG. 5;
FIG. 5b shows a partially cutaway sectional and exploded
perspective view of one form of resilient cushion employed as a
backup for a mold section;
FIG. 5c shows a cutaway portion in section of an alternative form
of of resilient backup means for mold section,
FIG. 5d shows a cutaway portion in section of still another
alternative form of resilient backup means,
FIG. 5e shows a cutaway portion in section of still another
alternative form of resilient backup means,
FIG. 6 shows a partially cutaway sectional and perspective view of
a linkage box, including the linkages and drive shafts for
vibrating a mold section;
FIG. 6a shows a sectional view along the line 6a-6a of FIG. 6;
FIG. 7 shows a partially exploded perspective cutaway and sectional
view of a corner insert and mounting structure for it; and
FIG. 7a shows a partially cutaway and sectional view of the lower
portion of the apparatus shown in FIG. 7.
The preferred embodiment of the invention shown in FIG. 1 consists
of an entire continuous casting machine 1 containing all of the
basic components of the machine in a modular unit. The machine is
provided with an upper rigid plate 2 and a lower rigid plate 3
which are spaced from each other and extend in planes parallel to
each other. The upper plate is provided with four grooves 4
extending at right angles to each other and radially outward from
the center line 5 of the casting machine. The lower plate 3 is also
provided with four radially extending grooves 6 which extend
directly opposite the grooves 4. These grooves 4 and 6 function as
keyways for relatively long rectangular keys 7 (FIG. 6) which are
also keyed into grooves 8 provided in the upper and lower surfaces
9 and 10 respectively, of a linkage box 11. In the particular
embodiment shown, there are four linkage boxes 11 because there are
four mold sections operated. Of course, if fewer or more mold
sections are employed, there will be required a linkage box 11 for
each mold section to be vibrated.
These linkage boxes 11 are suitably positioned and located radially
between the upper and lower plates 2 and 3 and then secured in
place suitably by means of screws 12 extending through the plates 2
and 3 and the keys 7 and into the upper surfaces 9 of the linkage
boxes 11.
Surrounding each linkage box 11 is a mold section support 13 which
is driven by means of the linkage and shafts contained therein, as
hereinafter more fully described. Each of the mold section supports
13 supports a mold section 14. Each mold section support 13,
particularly shown in FIGS. 1, 3 and 4, consists of a longitudinal
frame member 15 joined to two side plates 16. The side plates are
substantially triangularly shaped and provided with a rear brace 17
bridging between them. The frame member 15, the side walls 16 and
the rear brace 17 are suitably connected by welding or screws into
an integral box-like shape. The upper regions of the side plates 16
are provided with round openings 18 and the lower portions are
provided with other round openings 19. As hereinafter described,
these openings 18 and 19 provide journals for the ends of certain
shafts which are driven through orbital paths to cause the mold
section supports 13 to move through corresponding orbital
paths.
In order for the machine to cast a casting having a substantially
square cross section, the principal functional parts of the machine
are arranged as shown in FIG. 2. Four mold sections 14 are
alternately positioned with mold sections 14 in pairs facing each
other so that the inside surfaces 14a of the four mold sections 14
face inwardly toward the center of a cavity formed by the mold
sections 14 through which the casting 20 is propelled by the mold
sections 14. As previously mentioned, each mold section 14 is
supported by a frame member 15. Each of these frame members 15 is
provided with a T-shaped groove 21 extending for its entire length.
This groove 21 is bounded by two inwardly extending lips 22 having
rear surfaces 23 against which edge flanges 24 of each mold section
can abut as a limit on the movement of the mold section inwardly
toward the center line of the mold cavity. A rear wall 25 of the
frame member 15 provides the bottom surface of the T-shaped groove
21.
In the embodiment shown in FIG. 2, each mold section 14 is spaced
from the rear wall 25 by means of an inflatable cushion or pillow
in the form of a tube 26 which can be inflated to bear against the
mold section 14 and urge it inwardly toward the center of the mold
cavity. To act as a spacer shield and partial insulator between the
mold section 14 and the inflatable cushion 26, a flat stainless
steel strip 27 is positioned between the rear wall 14b and the
front wall 26a of the cushion 26.
The purpose of the inflatable cushion 26 is to provide a continual
pressure substantially uniformly along the entire length of a mold
section 14 to counteract any tendency of the mold section 14 to
objectionably bow or otherwise warp and to allow the mold section
14 to be displaced relative to its frame member 15 when the inside
surfaces 14a of the mold sections are brought firmly into contact
against the surface 20a of the casting 20.
In the co-pending application of James N. Wognum, Ser. No. 601,738,
filed Dec. 14, 1966, there is disclosed the use of corner inserts
for minimizing leakage at the corner regions between the mold
sections 14. In the embodiment shown in FIG. 2, these corner
inserts 27 are of substantially square cross section and positioned
between the side walls of adjacent mold sections 14 to bridge the
corners 28 of the casting 20. Similarly, to maintain the corner
inserts 27 in position, a T-shaped backing plate 29 is provided
with its leading edge abuting against the insert 27. This backing
plate has two shoulder surfaces 30 which are limited in their
movement toward the center of the mold cavity by other shoulders 31
on a frame member 32 which are surfaces of a T-shaped groove 33
extending longitudinally along the frame member 32. Provided in the
groove 33 is another inflatable cushion or tube 34 which, when
inflated, bears against a flat retaining strip 35 which in turn
presses against the rear surface of the backing plate 29 to urge
the backing plate into contact with a corner insert 27. The corner
inserts 27 are preferably made of small cross section, as
indicated, and of a material such as graphite which has a smooth
surface and is a good heat conductor.
One embodiment of the mounting construction for a mold section is
shown in FIG. 5. The frame member 15 is also substantially T-shaped
with flange portions 15a providing the means for securing the side
walls 16 thereto. The central region of the frame member 15 is
provided with a bore 36 through which coolant fluid is introduced
for maintaining the temperature of the mold section 14 at its
proper level. Secured to the rear lower face of the frame member 15
is a manifold 37 which carries suitable openings for the proper
introduction of coolant and air under pressure. In the embodiment
shown in FIG. 5, the manifold has an opening 38 leading to the bore
36, an opening 39 leading to the bore 40 and an opening 41 leading
to the bore 42. There is also an opening 43 which leads to a bore
44 which is a conduit for two wires 45 leading to and from a
proximity device 46, as hereinafter more fully described.
The same coolant that is introduced into the bore 36 returns after
it has passed through the upper length of the frame member 15 and
through openings 14c extending through the mold 14 until it reaches
the bore 42 and passes out through the opening 41 in the manifold
37.
Air under pressure is introduced through the opening 39 into the
bore 40 where it passes through the central bore 47 of a tube 48
around which the tubular stem 49 of the inflatable cushion 26 is
positioned to allow the cushion 26 to be inflated. This provides
the resilient backup for the mold section 14, as previously
described upon reference to FIG. 2. A suitable packing plug 50 is
provided in an enlarged portion 51 of the bore 40 in order to
suitably retain the pin 48 and the tubular stem 49.
As indicated in FIG. 5, the inflatable cushion 26 extends for a
substantial distance from adjacent the bottom of the frame member
15 to a location indicated at 52. Also, the mold section 14 is
unrestrained in longitudinal sliding movement relative to the frame
member 15 except at the upper end of the frame member 15 where
suitable retaining means is provided from which the mold section 14
is hung. This retaining means consists of a retainer block 53 which
is provided with a hollow bore 54 which connects with the bore 36
of the frame member 15 at an abutting region 55. The bore 54 has a
front surface 56 which closely abuts the rear surface 14b of the
mold section 14. A transverse rectangularly shaped key 57 extends
in suitable keyways 58 and 59 provided in the mold section 14 and
the retainer block 53 respectively. In order to assemble the mold
section into its proper location, the retainer block 53 is keyed to
the mold section 14 and manually together they are lowered into
place from the upper end of the frame member 15. After positioning,
set screws 60 threaded through openings in the upper rear portion
15b of the frame member 15 are tightened against the rear wall 53a
of the retainer block 53. In addition, an upper end cap 61 is
positioned against the upper end of the retainer block 53 and upper
end of the portion 15b of the frame member 15 and held in place by
means of screws 62 as a further retaining means for the retainer
block 53.
The bore 54 of the retainer block 53 is L-shaped to lead into the
upper ends of the bores 14c of the mold section 14 so that there
can be a complete circuit of flow of coolant through the frame
member 15, the retainer block 53 and the mold section 14.
At all necessary junctures between the parts where there is fluid
flow of coolant, suitable O-rings are provided to prevent leakage.
For example, an O-ring 63 is provided at the upper end of the
assembly between the bore 54 of the retainer block 53 and the bores
14c of the mold section 14.
With the arrangement shown, it should be apparent that the mold
section 14 is truly hung from the upper end of the frame member 15
and it is free to expand and contract longitudinally as it is
guided in the T-shaped opening 21 of the frame member 15. This lack
of restraint, minimizes the tendency to bow or warp which is
evident in mold constructions having fully restrained mold
sections.
In order to maintain a leakproof seal at the lower end of the mold
section 14 which is free to deflect radially of the machine, a
plunger 64 is provided in the bore 42. The plunger 64 is provided
with a helical spring 65 encircled about it which reacts against a
wall 66 of the frame member 15 and an annular flange 67 on the
plunger 64. The spring 65 urges the plunger toward the opening 41
in the manifold 37. When the mold section 14 is properly
positioned, air is supplied through the bore 40 to inflate the
inflatable cushion 26. Simultaneously, the air is directed through
another small bore 68 leading to an annular region 69 in the rear
of the annular flange 67. The air pressure urges the plunger 64 in
a direction away from the opening 41 in the manifold 37 and toward
the mold section 14. The end of the plunger 64 is provided with an
O-ring 70 which is thereby urged into intimate contact around the
openings leading to the bores 14c of the mold section 14 to thereby
provide a fluid type connection. When it is necessary to remove a
mold section 14 for replacement or repair, the air pressure is
removed from the bore 40 which relieves the pressure in the
inflatable cushion 26 and against the annular flange 67 of the
plunger 64 so that the spring return relieves the pressure of the
O-ring 70 from against the mold section 14. At that time, upon
suitable loosening of the set screws 60 and the screws 62, the mold
section 14 can be removed from the upper end of the assembly.
The proximity device 46 is one which provides a signal in the form
of a change in DC voltage when there is a change in the presence of
metal adjacent the front surface 46a of a detector 46b. A suitable
proximity device is one which can be purchased from Bently Nevada
Corp., Box 157, One Airport Road, Minden, Nevada. The change in
presence of metal is sensed by the detector 46b which is connected
by the wires 45 to a detector driver 46a which has a DC voltage
output which varies with the change in presence of metal at the
detector. The variation in voltage output can be visually indicated
on a meter 46d.
A proximity device 46 is provided in each mold section support 15
and there is a corresponding detector driver 46c and meter 46d for
each proximity device 46. In operation, the mold sections 14 are
placed in their orbital vibratory paths by means of their mold
section supports 15 suitably driven through the drive systems
mentioned by means of the motors 140. With no casting metal
present, the inflatable tubes 26 keep the mold sections 14 pressed
radially toward the center of the mold so that the edge flanges 24
of each mold section abut against the rear surfaces 23 of the
inwardly extending lips 22 on the mold section supports 15. As
casting begins, the metal casting travels through the mold cavity
of the machine. The metal adjacent the top of the mold fills the
cavity and presses against the inside surfaces 14a of the upper
ends of the mold sections 14. However, ordinarily the casting
shrinks as it progresses through the mold cavity so that there is a
tendency for the mold portions of the inside surfaces 14a of the
mold sections 14 to be out of contact with the casting at its lower
end. To overcome this, the eccentric adjustments are made on the
pins 130 to adjust the links 133 radially inwardly toward the
center line 5 of the mold cavity until the inside surfaces 14a of
the mold sections contact the casting. The indication that contact
has been made by a mold section against the casting is when a
cyclical pulsing of increasing and decreasing voltage appears on
the meter 46d. This signifies that the mold section 14 is
cyclically pressing against the casting as its edge flanges 24
reciprocate away from and toward the lips 22 of the mold section
support 15. In order to make the proper adjustment, the eccentrics
on the pins 130 are adjusted until the cyclical voltage variations
on the meters 46d are pronounced and then the eccentric adjustments
are made until the cyclical voltage variations are minimal. That
point is reached when the edge flanges 24 of the mold sections 14
no longer reciprocate back and forth away from the lips 22 of the
mold section supports 15.
The proximity device 77 indicated in FIG. 5a is of the same kind as
proximity device 46 and it is suitably connected by wires to a
detector driver and a meter similar to items 46c and 46d for proper
operation. Its adjustment is in an identical manner for the mold
section 72 as for the mold section 14 when employing the proximity
device 46.
As an alternate to the mold section support indicated in FIG. 5,
there is another embodiment shown in FIG. 5a. There are basically
the same components but their structures are somewhat different.
There is a manifold 71 corresponding to the manifold 37, a mold
section 72 corresponding to the mold section 14, a frame member 73
corresponding to the mold section 14, a frame member 73
corresponding to frame member 15, an inflatable cushion 74
corresponding to inflatable cushion 26, a bore 75 through the frame
member 73 corresponding to bore 36, a bore 76 corresponding to bore
40, a proximity device 77 corresponding to the same device 46 and a
plunger 78 corresponding to plunger 64. There is also a spring 79
which acts reversely of the spring 65. Spring 79 urges the plunger
78 toward the mold section 72 rather than away from it, as does
spring 65.
The lower end of the mold section 72 is provided with a sloped
surface 80 which reacts against the leading surface 81 of the
plunger 78 which is urged against the mold section 72. The plunger
surface 81 is likewise directed along the same angular inclination
as the surface 80 and the plunger 78 is guided in a bore 82 which
is similarly sloped and which carries the spring 79. With this
construction, as the mold section 72 is lowered into position, its
lower surface 80 cams against the surface 81 of the plunger 78 and
the plunger 78 remains in contact with the mold section 72 by the
action of the spring 79, regardless of the relative position of the
mold section 72 radially relative to the center of the mold. This
system of maintaining a fluid-type connection at the lower end of
the mold section 72 has the advantage that no air pressure is
required. Instead, reliance on a spring is all that is
necessary.
Another significant difference is the manner in which the mold
section 72 is suspended from the upper end of the assembly. The
upper end of the mold section 72 is provided with a keyway 83 which
engages with a shoulder 84 of a retainer block 85. The retainer
block 85 has a sloped bottom surface 86 which mates with a
correspondingly sloped surface 87 at the upper end of the frame
member 72. For assembly purposes, the mold section 72 is assembled
to the retainer block 85 by engaging the shoulder 84 with the
keyways 83. In assembled form the mold section 72 is then lowered
into a T-shaped slot corresponding to the slot 21 in the frame
member 15. Another surface 86 bottoms on the surface 87 and further
downward urging of the retainer block 85 causes tighter engagement
of the shoulder 84 in the keyway 83. This provides an insured
tightness. Then, with the retainer block 85 and the mold bar 72 in
position, an end 88 is positioned above the retainer block 85 and
secured in place by means of screws 89 extending through the cap 88
and the frame member 73.
Although the inflatable cushion 26 can be made of molded plastic or
rubber in a single piece, the inflatable member 74 is shown to be
of a different construction. As indicated in FIGS. 5a and 5b, it
consists of a flattened tube 74a as a main body portion which can
be made of thin wall brass tubing or other metal. The ends of the
tube 74a are provided with plugs 74b which are preferably made of
brass and silver soldered in place. Also soldered at the lower end
of the tube 74a is a sleeve 74c which is provided with a central
bore 74d which leads to an opening 74c in the wall of the tube 74a
so that air under pressure can be introduced into the tube 74a.
Because of the limited travel required of the expanding walls of
the tube 74a, this particular structure is quite suited for the
purpose intended, especially because of its greater durability over
the inflatable cushion 26 made of rubber or plastic. In addition,
as a suitable shield for the inflatable cushion 74, flat strips 90
and 91 of stainless steel are positioned along opposite surfaces of
the tube 74a.
Another important feature of the mold section 72 is the use of
transverse grooves 92 cut into the mold action 72. The purpose of
these is to make the mold section 72 as flexible as possible so
that minimum forces are required to keep the mold section 72 free
of an undesirable warpage from thermal stresses and to allow the
mold section to conform to the shrinkage contour of the surface of
the casting.
With reference to FIGS. 7 and 7a, each of the corner inserts 27 is
supported in a manner similar to each of the mold sections 14 or
72, as previously described with reference to FIG. 2. Further,
although inflatable cushion 34 shown in FIG. 2 can be made of
rubber or plastic, it can also have a construction similar to that
which is shown in FIG. 5b for the inflatable cushion 26.
As indicated in FIG. 7, the backing plate 29 or the corner insert
27 can be provided with transverse slots 93 which are intended to
make the backing plate 29 more flexible. There is no equivalent of
the backing plate 29 shown for the support of the mold sections 14
or 72. These slots 93 extend to intersect circular bores 94
extending transversely through the backing plate 29 for the purpose
of minimizing stress concentrations which can lead to cracking. The
upper end of the assembly is provided with an end cap 95 which is
held in place on the frame member 32 by means of two screws 96.
This end cap 95 keeps the backing plate 29 securely positioned.
This arrangement makes it very simple to replace corner inserts 27
which may become damaged or broken.
Keyed to two projecting key portions 97 and 98 at the rear of the
frame member 32 are two brackets 98 and 99 which are provided with
mounting holes 100 and 101 which permit securement to the upper and
lower plates 2 and 3 of the machine.
As indicated in FIG. 7a, there is shown the details of the lower
portion of the assembly for holding corner insert 27. The bracket
99 is secured to the frame member 32 by means of two screws 102 and
103 and a locating pin 104. The screw 102 and the locating pin 104
extend through another mounting bracket 105 which has a vertical
wall 106 against which the frame member 32 rests. An upper wall 107
of the mounting bracket 105 provides support for a cover plate 108
secured to the bottom end of the backing plate 29 and the backing
plate 108 also supports the lower end of the corner insert 27. The
screw 103 passes through a threaded hole 109 which is sloped
downwardly so that the end of the screw 103 can react against a
sloped surface 110 on the frame member 32 to thereby firmly retain
the assembly by urging the frame member 32 snugly against the
vertical wall 106 of the mounting bracket 105. The inflatable
cushion 26 is of the same general construction as the cushion 74a
shown in FIG. 5b, as employed as a backing for the mold sections 14
or 72. However, the other type made of rubber or plastic can also
be employed. However, as shown in FIG. 7a, the lower end of the
inflatable cushion 26 is provided with an inlet conduit 111 which
is preferably silver soldered to the cushion 26 and which permits
the inflating of it with a source of pressurized air. In addition,
the backing plate 29 shown in FIG. 7a is provided with additional
slots 112 which can be added along the front edge of the backing
plate 29 to further increase the flexibility of the backing plate
29 to further minimize the forces required to resist undesirable
warpage or deformation due to thermal stresses.
As shown in FIG. 6 and partially in FIG. 1, the linkage box 11 has
two side walls 11a which are joined with upper wall 9, the lower
wall 10 and front and back walls 11b and 11c to provide an entirely
enclosed container for the linkages required to properly actuate
the mold sections.
Within each linkage box 11 is a main driven link 113 which is
journaled at its lower end 114 on an eccentric portion 115 of a
shaft 116. The upper end of the link 113 is pivoted on a pin 117 to
one end 118 of a link 119. The other end 120 of the link 119 is
journaled on a shaft 121 whose outer ends on either side of the
link are journaled in a fixed position in the side walls 11a of the
linkage box 11. Adjacent to the upper end of the link 113 is
another shaft 122 which extends through the side walls 11a of the
linkage box 11 clear of any contact with the linkage box 11 and
journaled into the openings 18 previously mentioned as provided in
the side walls 16 of the mold section support 13. Suitable bushings
or other bearings can be provided for increasing durability of
these bearing connections.
Intermediate between the upper and lower ends of link 113 is
another pin 123 extending through the link 113 with its ends
journaled in one end 124 of a link 125 whose other end 126 is
journaled on a pin 127 mounted at the upper end 128 of a link 129.
The link 129 extends substantially parallel to the link 113 and has
its lower end provided with a pin 130 whose ends are journaled in a
fixed position in the side walls 11a of the linkage box 11.
Slightly above the lower end of the link 129 another pin 131 is
provided in the link 129 with its ends extending laterally
therefrom and journaled to one end 132 of another link 133 whose
other end 134 is provided with a shaft 135 extending laterally from
both sides of the link 133 and through the side walls 11a of the
linkage box 11 without any contact thereof and journaled in the
holes 19 previously referred to in the side wall 16 of the mold
section support 13. Suitable bushings or other bearing means can be
provided in these regions for durability, similar to what are
provided for shaft 122.
Two spacers 136 and 137 are provided between the side walls 11a of
the linkage box 11 and they are suitably secured in place by screws
or other fastening means.
With the linkage arrangement disclosed, it should be apparent that
rotation of the main shaft 116 causes its eccentric portion 115 to
provide a vibratory orbital movement of the lower end 114 of the
link 113. This orbital motion is imparted to both of the shafts 122
and 135. Such motion is delivered to the shaft 122 directly through
the link 113. Such motion is delivered to the shaft 135 through the
link 125, the link 129 and the link 133. Suitable variations in the
positions of the shafts 122 and 135 relative to the linkage box 11
can be obtained by providing the shafts 121 and 130 with adjustable
eccentric bearing supports for the end portions of the links 119
and 129 they support which shafts 121 and 130 are adjustable by
rotation. The purpose of these adjustments is to vary the location
of the shafts 122 and 135 relative to the linkage box 11 in order
to vary the positioning of the mold sections 14 or 72 as desired.
By having variations on both shafts 121 and 130, it is possible to
vary the in and out positions of either the upper end or lower end
of each mold section 14 without any significant change in the
location of the other end not adjusted. In FIG. 6a, a suggested
mounting for eccentric adjustment of the shaft 130 is shown. The
shaft 130 is provided with a central portion 130a which is
eccentric of the center line 130b of the shaft 130. Two reduced
portions 130c and 130d of the shaft 130 are journaled directly in
bearings 130c and the free end 130f extends beyond the portion
130c. A nut 130g is threadably secured on a threaded portion 130h
of the shaft 130 and ordinarily tightened against a shoulder 130i.
The eccentric portion 130a is mounted in a lower bearing 130j which
journals it to the link 129. When it is desired to adjust the
spacing of the shaft 130, the nut 130g is loosened and the shaft
130 is rotated by external access to the end 130f. The shaft 130 is
rotated until the eccentric portion 130a rotates sufficiently to
properly adjust the position of the bottom end of the link 129.
This adjustment of the bottom end of the link 129 in turn adjusts
the position of the link 133 and, in turn, that of the shaft 135.
Similarly, the shaft 121 can be provided with an adjustment
identical to that as shown for shaft 130 is FIG. 6a in order to
adjust the position of the link 119 to, in turn, adjust the
position of the shaft 122.
Another manner of acquiring some adjustment, not indicated, is to
provide each link 119, 125 and 133 with a turnbuckle centrally
located on each one. Rotation of the turnbuckle can provide
lengthening or shortening of the link desired. The advantage of the
eccentric adjustment is that it can be arranged for external
adjustment while the machine is operating.
The main shaft 116, as indicated in FIG. 1, is coupled at 138 to
the drive shaft 139 of a driving motor 140. In the arrangement
shown, there are four linkage boxes 11 because there are four mold
sections shown as required to be driven and, likewise, there are
four motors 140 for driving them. The motors are of a standard
synchronous type so that the proper phase relationship of the
motion of the mold sections can be maintained at all times during
the operation of the device.
In order to maintain lateral stability of the mold sections, the
mold section supports 13 are held in position by links 141 and 142.
Link 141 extends between a side wall of the mold section support 13
and a bracket secured to the undersurface of the bracket plate 2.
Link 142 connects between a side wall of the mold section 13 and a
plate 143 which supports one of the motors 140. These links 141 and
142 are journaled at their ends to allow for the movement of the
mold section supports 13 as they move through their orbital
vibrations.
In order to provide a tight, rattle-free movement of each mold
section support 13 without the use of precision bearing mounts, a
takeup device 144 is provided on each rear brace 17 of each mold
section support 13. Its components are particularly shown in FIG.
1a where each takeup device 144 has an outer cup-shaped shell 145
which is welded directly to a rear brace 17. Contained within a
cavity 146 of the shell 145 is a plunger 147 which bears against
the outer end of a coil spring 148 having an inner end which bears
against the outer wall 11c of a linkage box 11. Secured by screws
149 to the outer wall 11c is a spring end positioning plate 150
provided with a circular opening 151 of slightly larger diameter
than that of the spring 148 so that the end of the spring 148 can
be contained in this opening 151. The outer end of the shell 145 is
provided with a threaded opening 152 connected with an adjusting
screw 153 which can be threadably adjusted along the opening 152 to
provide for more or less compression of the spring 148 and thereby
adjust the reaction forces of the spring 148 between the mold
section support 13 and the linkage box 11. The purpose of this
spring pressure is to bias all of the linkage shaft trunnion
connections in one direction to remove any slack or looseness and
thereby create a tight operating condition between the moving
parts. This maintains the desired tight condition even though the
trunnion connections may not be precision fit and permits the use
of standard bearings to minimize the cost of the installation.
Further, the fact that the linkages and mechanisms associated
therewith are contained entirely within the linkage boxes 11
without any external exposure, there is excellent protection for
these parts from dust or dirt in the area where the machine is to
be used.
In the operation of the device, the synchronous motors 140 are
operated to rotate the drive shafts 139 and cause the mold sections
14 or 72 to vibrate through small orbital paths. Experience
indicates that the bottom radial amplitude of vibration and the
longitudinal amplitude of vibration relative to the longitudinal
axis 5 of the mold can vary over a wide range with satisfactory
results, and the operating frequency can also vary in a very wide
range up to 50,000 cycles per minute and more. The amplitude
selected are dependent upon the frequency chosen and the
combination of amplitudes and frequency are selected on the basis
of the desired surface condition sought on the casting and the
speed of travel of the casting through the mold. Ordinarily, the
opposite positioned mold sections 14 are vibrated approximately
180.degree. out of phase with the other two mold sections. In this
manner, there are substantially always two mold sections
approaching the casting 20 while the other two mold sections are
moving away from the casting 20. This type of movement is fully
described in U. S. Pat. No. 3,075,264.
The frame members 15 are preferably made of a metal having a very
low coefficient of thermal expansion at the operating temperatures
of the machine which, in the vicinity of the frame members 15 is
approximately 200.degree. F. A very suitable metal is a low
expansion alloy commonly known as "Invar" metal having an average
coefficient of thermal expansion between 0.degree. and 200.degree.
F. of about 0.7 .times. 10.sup..sup.-6 which is very low as
compared to other metals generally. "Invar" is an iron-nickel alloy
having approximately 36 percent nickel. It is important that these
frame members substantially retain their shape without significant
warpage due to any thermal gradient in order to provide the rigid
backup for the mold sections which are themselves flexible. It is
important that the backup means be rigid and thereby provide
tensioned stability to the apparatus. If the frame members 15 did
excessively warp, due to a thermal gradient, the range of free
movement provided for the flexible mold sections could be
restricted too much so that binding of the casting in the mold
could occur with resultant hampering of advancement of the casting
through the machine.
As alternatives for the resilient backup means shown in FIGS. 2, 5,
5a, and 5b, for the mold sections 14 and 72, and the corner inserts
27, a construction indicated in FIGS. 5c, 5d or 5 e can be
employed. In FIG. 5c, a mold section 160 identical to mold section
72 is shown mounted on the frame member 161 similar to frame member
73, except it is machined to accommodate a plurality of coil type
compression springs 162 retained in a plurality of recesses 163
extending in spaced relationship along the length of the frame
member 161. These coil springs 162 react against the bottom ends
163a of the recesses 163 and a separator strip 164 which is
positioned against the inner surfaces 160a of the mold section 160.
There is a space 165 between the strip 164 and the frame member 73
to permit the required range of movement of the mold section 160
relative to the frame member 161 against the resilient pressure of
the springs 162. With this arrangement, there is no requirement for
fluid pressure as the resilient force against the mold section 160.
In a similar manner, the corner inserts 27 can be adapted with
suitable springs 162 instead of inflatable cushions or tubes
34.
As a further alternative construction, the parts as indicated in
FIG. 5d can be employed. The construction is similar to that which
is shown in FIG. 5c, except that the recesses 166 shown are larger
than the recesses 163 shown in FIG. 5c. This is necessary to
accommodate plungers 167 which substantially surround the springs
162. These plungers 167 react between the springs 162 and the
separator plate 164, instead of having the springs bear directly on
the separator plate 164. Otherwise the construction is the
same.
In FIG. 5e is still another construction which does not employ the
use of springs. Instead, it is another form which employs fluid
pressure introduced through a bore 168 which is substantially
similar to bore 76 shown in FIG. 5a. However, the frame member 169
shown which supports the mold section 160 is provided with a
passage 170 connected with the bore 168 to receive fluid under
pressure from the bore 168. The passage 170 is connected by a
plurality of smaller passages 171 to a plurality of cylindrical
recesses 172 which contain pistons or plungers 173 guided for
reciprocation therein. Each plunger 173 is provided with an annular
fluid seal 174 to minimize or prevent leakage of fluid from the
passage 170 beyond the plungers 173 in the direction of the mold
section 160. A retainer strip 164 is disposed between the plungers
173 and the mold section 160. It should be evident that the
plungers 173 when provided with fluid under pressure from the
passage 170 will cause them to bear with resilient pressure against
the retainer strip 164 to, in turn, transmit the force to the mold
section 160. This effect is quite similar to that achieved when
employing the inflatable cushion or tube, previously described.
It should be evident that the structure shown in FIGS. 5c, 5d and
5e are all suitable constructions for providing resilient backup
means for either the mold sections 160, or the like, or for the
corner inserts 27, or the like.
Although the invention has been described as one relating to a
particular type of vibratory casting machine, some of the
principles can still be applied to other casting machines employing
separate mold sections as opposed to the sleeve type mold. Further,
although only a single embodiment and variations thereof of the
invention have been shown and described, it should be clearly
understood that the invention can be made in many different ways
without departing from the true scope of the invention as defined
by the appended claims.
* * * * *