Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02358077 2001-09-20
DEAD LE'JER LUG
S
BACKGR(7UND tJF T>'-IE INVENTION
Field of the Invention.
The present invention relates to railway trucks, and more particularly, to
dead lever lugs for
mounting on bolsters of three-piece railway trucks.
Description of the Prior Art.
In the past, in making hollow cast metal bodies, it has been known to use
cores made of
bonded sand supported in green sand molds to produce the hollow castings. The
cores have been
1 S used to create the hollows or open spaces in the castings. .
Cares have commonly been made in core boxes, typically having cope and drag
halves that
are brought together along a parting line. There is a cavity in the core box,
and a mixture of sand
and bonding material are introduced into the cavity and cured. 'The core box
cope and drag portions
are then parted along the parting line, generally being pulled apart
vertically. Because of the need to
2Q pull the cope and drag portions apart, the sizes and shapes of the cores to
be produced have been
limited: the cores have nat been able to have parts that would interfere with
the movement of the
cope portions away from the drag and with removal of the cores from the cope
and drag portions.
Thus, it typically has been necessary to produce several different cores that
are later joined or placed
together in the green sand mold.
25 In the case of cast metal sideframes for railway trucks, many different
core shapes have been
needed to produce the basic shape of the interior of the sideframes. As shown
ira FIGS. 1 S-17, more
than twenty cores have been required, with some different cores sometimes
adhered together in a
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CA 02358077 2001-09-20
separate process step before being placed in a receiving cavity in the mold,
and with many different
cores and groups of cores separately placed in the mold. While some cores such
as a window core
and bolster opening cores have been supported on core prints, many of the
cores have been
supported on chaplets on the mold surface. In addition to the placement of the
cores being a labor
intensive operation, the use of such multiple cores has been problematic from
a quality control
standpoint. With so many joints between the faces of the multiple cores, there
is a potential fox
many fins to be formed on the interior of the casting. To remove these fins
through a finishing
operation has been difficult since the fins are on the interior of the
casting. Moreover, these fms
create another potential quality control problem since they could give rise to
stress risers that could
form along the fms. Other potential quality control problems arise from the
potential for shifting of
the cores' positions in the mold prior to or during the casting operation. If
the cores shift position,
the thickness of the walls of the casting could vary from the design.
In addition, multiple cores may be so thin that core rods are required to be
used to support
the sand. These core rods add to the cost of the process and complicate
cleaning of the castings.
Another problem can arise in connection with axeas of the sideframe around
lightener holes
and other openings in the sideframe wall. Metal fins can form around these
openings, and
sometimes form facing the interior of the casting. To finish such a casting by
removing these fins
may be difficult to accomplish manually since the fins are less accessible to
the worker. In addition,
it is very difficult to remove interior fins through automation.
Similar problems have arisen in praducing cast metal bolsters for use in
railway trucks. Like
the sideframes, bolsters have hollow interiors, and have traditionally been
made with multiple cores
to form the interior walls and interior surfaces of the outer walls. Sixteen
separate cores have been
used to produce such castings, with cope and drag portions sometimes adhered
tc: each other or
juxtaposed along joints, as in the case of the sideframes cores, with chaplets
supporting the cores on
the mold surface, and with separate cores inserted into the cores to define
holes for bolting side
bearings and dead lever Lugs to the bolster.
Similar problems as those outlined for sideframes have arisen with respect to
qualit~~ control
for bolsters. The positions of the cores on the chaplets may shift in the
mold, creating the potential
for making a casting with less than or more than desirable wall thicknesses.
Boaster production has
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CA 02358077 2001-09-20
required that the multiple cores be placed in a mold in a labor intensive
operation with multiple
joints where stress risers could form. And like the sideframes, interior fins
could form around
lightener and other openings, fms that could be difficult and labor intensive
to remove and that are
not conducive to removal through automated finishing operations. Moreover,
fin: can form on the
edges of the openings which can be stressed and damaged during the removal
operation in the case
of both sideframes and bolsters.
Some features of traditional bolsters have been problematic in core and core
box design. As
shown in FIG. 22A, prior art bolsters for three-piece trucks frequently
provided a flat raised
mounting area for mounting dead lever Lugs to the side of the bolster. Parts
of the brake system are
supported by or suspended from the dead lever lugs. The raised mounting area
on the bolster
provides a flat mounting surface that spans a radius in the bolster side wall
so than the a flat surface
of the dead lever lug can be mounted against the flat mounting surface on the
bolster. This flat
mounting area on the side of the bolster is formed during casting of the
bolster, and requires that the
bolster core have an outstanding surface to define the mounting surface.
SUMMARY OF THE INVENTION
The present invention addresses the problem. presented by consolidation of the
cores used to
make a bolster while also allowing for a dead lever lug to be mounted on the
bolster in the
traditional location.
In one aspect, the present invention provides a dead lever lug for mounting on
a side wall of
2(1 a bolster of a railway truck. The bolster side wall has two non-parallel
surfaces meeting along a
juncture. The dead lever lug includes a pair of arms connected to each other.
Each arm has a
mounting surface shaped to mate with one of the two non-parallel surfaces of
the side wall of the
bolster. The mounting surfaces of the arms are separated by a gap for spanning
the juncture of the
two non-parallel surfaces of the bolster side wall.
'~ 5 In another aspect, the present invention provides a dead lever lug for
mounting on a side
wall of a bolster of a railway truck. T'he bolster has a side wall. The dead
lever lug includes a
mounting side facing the bolster side wall when the dead lever lug is mounted
on the bolster. The
mounting side of the dead lever lug includes at least three surfaces lying in
separate planes.
CA 02358077 2001-09-20
BRIEF' DESCRIFTIc'~1~1 GF THE DRAWINGS
FIGURE 1 is perspective view of a railway car truck, with sideframes and a
bolster.
FIGURE 2 is a top plan view of a sideframe that may be made according to the
present
invention.
FIGURE 3 is a side plan view of a sidefrarne made according to the present
invention with
parts shown in section.
FIGURE 4 is an enlarged partial perspective view of the top member of the
sideframe of
FIG. 2.
1 ~ FIGURE 5 is a cross-section taken along line S-5 of FIG. 4.
FIGURE 6 is a top plan view of the four one-piece sideframe cores of the
present invention
in place in a drag mold flask with other cores shown for purposes of
illustration.
FIGURE 6A is an enlarged partial cross-section of a partion of a sideframe
core received
within the cope and drag portions of a mold.
1 S FIGURE 7 is a perspective view of the four one-piece sideframe cores,
showing the portions
that are provided to rest against the drag side of the mold surface.
FIGURE 7A is a partial crass-section ofthe one-piece end core of FIGS. f>-7,
showing the
locator bass received in a mating hole in the drag mold surface.
FIGURE 8 is an exploded perspective view of the four one-piece sidefram.e
cores, showing
2~ the opposite side of cores shown in FIG. 7.
FIGURE 8A is a partial cross-section of the central opening of the center
.:ore of FIGS. G-8,
showing lift arms engaging the core for lifting and moving the core.
FIGURE 9 is a perspective view of one of the one-piece sideframe end cores of
the present
invention.
25 FIGURE 10 is a partial perspective view of the sideframe bottom center core
end of the
diagonal tension arm portion of the sideframe end core of FIG. 9.
FIGURE 11 is a partial side plan view of one of the core prints of the core of
FIG. 9.
FIGURE 12 is a perspective view of the bottom center core of FIGS. 6-8.
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FIGURE 13 is an enlarged partial perspective view of one end of the bottom
center core of
FIG. 12.
FIGURE 14 is a perspective view of the sideframe center core shown in FIGS. 6-
8.
FIGURE 1 S is a perspective view of some of the multiple prior art sideframe
cores replaced
by the consolidated one-piece end core of the present invention.
FIGURE 16 is a perspective view of some of the multiple prior art sideframe
cores replaced
by the one-piece sideframe center core of the present invention.
FIGURE 17 is a perspective view of a part of the prior art cores replaced by
the one-piece
bottom center core of the present invention.
FIGURE 18 is a partial cross-section of a sideframe made using the cores of
the present
invention, taken along the longitudinal centerline of the sideframe.
FIGURE 19 is a partial cross-section of a sidefrarne made using the cores of
the present
invention, taken along the longitudinal centerline of the sideframe, showing
the opposite side shown
in FIG. 18.
1 ~i FIGURE 20 is a partial perspective view of one of the columns, with part,
broken away,
showing a friction plate in place on one column, with the mounting nuts, bolts
and washers shown
in exploded view.
FIGURE 2I is a cross-section taken along line 21-21 of FIG. 20.
FIGURE 22 is a side plan view of a prior art bolster, with part shown in cross-
section.
FICrURE 22A is a partial top plan view of the prior art bolster of FIG. 22,
showing the
mounting of a dead lever lug on a flat aria of the bolster.
FIGURE 23 is a side plan view of a bolster made according to the present
invention, with
part shown in cross-section.
FIGURE 23A is a partial cross-section of a rib of the bolster of FIG. 23.
FIGURE 24 is a top plan view of the bolster of FIG. 23.
FIGURE 25 is a perspective view of a prior art core used in making the prior
art bolster.
FIGURE 26 is a perspective view of another prior art core used in making a
prior a~ bolster.
FIGURE 27 is a perspective view of another prior art core used in making the
prior art
bolster.
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CA 02358077 2001-09-20
FIGURE 28 is a perspective view of another group of prior art cores used in
making the
prior art bolster.
FIGURE 29 is a perspective view of another group of prior art cores used in
making the
prior art bolster.
S FIGURE 30 is an exploded side plan view of the three one-piece bolster cores
of the present
invention.
FIGURE 31 is a perspective view of the three one-piece cores of the present
invention with
the two one-piece end cores resting on the ane-piece center core.
FIGURE 32 is a perspective view of an embodiment of a one-piece bolster center
core of the
present invention.
FIGURE 33 is a perspective view of another embodiment of a one-piece bolster
center core
of the present invention.
FIGURE 34 is a top plan view of the bolster center core of FIG. 32.
FIGURE 35 is a cross-section of the bolster center core of FIG. 34, taken
along line 35-35.
FIGURE 35A is a partial cross-section along line 35A-35A of FIG. 34.
FIGURE 36 is a perspective view of a one-piece bolster end core of the present
invention.
FIGURE 37 is another perspective view of the one-piece bolster end care of
FIG. 36.
FIGURE 38 is a. perspective view showing the three one-piece bolster cores of
the present
invention in place in the drag side of a mold flask.
FIGURE 39 is a partial cross-section showing the position of one of the cores
of the present
invention relative to the cope and drag parts of a mold.
FIGURE 40 is a perspective view of the drag side of a core box that may be
used to make
the sideframe center core.
FIGURE 41 is a side view of a dead lever lug that may be used with the
lyolster of the
present invention.
FIGURE 42 is a top plan view of the dead lever lug of FIG. 41.
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CA 02358077 2004-04-16
DETAILED DESCRIPTION
A railway truck 10 that may utilize cast metal components of the present
invention is
illustrated in FIG. 1. As there shown, a typical railway truck 10 includes a
pair of wheelsets 12,
each wheel set having an axle 14 with a wheel 16 at the end of each axle 14.
The two wheelsets
12 support a pair of spaced, parallel sideframes 18. The two sideframes 18
have longitudinal
centerlines 19 and are spanned by a bolster 20, which is received in a bolster
opening 21 in the
middle of each sideframe. The bolster rides on a springset 22.
The present invention provides improved sideframes and bolsters, and methods
of
making such cast metal bodies, as well as cores to be used in making such cast
metal bodies. Use
of the method and cores of the present invention should be beneficial in
simplifying the making
of cast metal sideframes and bolsters, as well as in improving the quality and
reducing the weight
of such products. The principles of the casting method and core designs should
also prove
applicable to the production of other cast metal bodies.
The sideframes disclosed in United States Patent No. 5,481,986, issued January
9, 1996
to Charles P. Spencer, Franklin S. McKeown and Donald J. Lane and assigned to
Amsted
Industries Incorporated, Chicago, Illinois, may be made in accordance with the
principles of the
present invention.
As shown in FIGS. 2-5, a sideframe 18 made in accordance with the present
invention
generally includes a top member 24 having a center portion 26 and two similar
top end portions
28 connected with the center portion 26 through compression member portions
27. At the front
and rear ends 30, 32 the sideframe has pedestal jaws or pedestals 34 to be
mounted on a wheelset
12 as illustrated in FIG. 1. Each pedestal includes an outer pedestal leg 29,
a roof 31, an inner
pedestal leg 33 and a journal bracket flange 35.
Each sideframe 18 also includes a tension member or lower member 36 comprised
of a
bottom center portion 38 and two integral diagonal portions 40 each extending
from the bottom
center portion 38 toward the pedestals 34. A spring seat 42 is on the bottom
center portion 38 of
the tension member 36, between the bottom center portion 38 and top center
portion 26 of the top
member 24. The middle of the sideframe has a lower bolster opening 44 above
the spring seat 42
to receive the spring set as shown in FIG. 1. The middle of the sideframe also
has a bolster
opening 21
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CA 02358077 2001-09-20
between the lower bolster opening 44 and the top center portion 26 of the top
member 24 to receive
the end of the bolster 20 as shown in FIG. 1. A column 48 extends between the
tap member 24 and
tension member 36, along each side of the bolster opening 21 and lower bolster
opening 44. Each
sidefrarne 18 also has two side windows 50. Each side window 50 is between
thE: bolster opening
21 or columns 48 and the pedestals 34 at the front and rear ends 30, 32 of the
sidefrarne 18, between
the end portions 28 of the top member 24 and diagonal arm portions 40 of the
tension member 36.
T'he illustrated sideframe 18 is hollow, with exterior 52 and interior 54
sides or surfaces of
its cast metal walls 56. There are a plurality of openings in the cast metal
walls 56, including
lightener openings 58 in the top surfaces of the top member 24. Other openings
ti0 are provided, for
example, in the walls between the side windows 50 and the diagonal arm
portions 40 of the tension
member, between the side windows 50 and the top end portions 28 of the top
member 24, and in the
lower surface of the center portion 26 of the top member 24. The walls 56 at
each opening have an
edge 62, as shown in FIGS. 4-5, that curves outwardly, that is, the edge 62 is
convex.
As used herein, references to the "tension member" 36 and "diagonal portions"
40 of the
tension member are not intended to include the journal bracket flanges 35 and
inner pedestal legs
33, shown in FIG. 3, unless otherwise noted.
As shown in FIG. 5, the illustrated edges have radii of curvature designated
"r" and each
illustrated edge has two centers of curvature designated "c~" and "cz". The
radii of curvature "r" are
about one-half the thickness of the metal walls 56, represented by the
designation "x" in FIG. 5.
'I'lxe centers of curvature c, and c2 are aligned, with the outermost center
of curvarure cl at a distance
less than "x" from the outer surface of the metal and the innermost center of
curvature c2 centered
between. the outer and inner surfaces of the metal wall. The distance "x" is
less W an "r" in the
illustrated embodiment In the illustrated embodiment, the sideframe walls have
rhicknesses at the
Iightener openings of about one-half inch, and the radii of curvature of the
edges 62 are about one-
quarter inch, with c, positioned less than one-qua.~ter inch from the outer
surface and c2 positioned
one-quarter inch frarn. the inner and outer surfaces. Alternatively, the cast
metal wall could have a
single center of curvature, with, for example, a radius of curvature greater
than one-half the
thickness of the metal, that is, greater than the distance '°x" shown
in FIG. 5.
CA 02358077 2001-09-20
'The curved edges 62 of the sideframes at the lightener openings 58 and other
openings 60
are formed by the method of the present invention, using unique cores 64
having unique core prints
66 as illustrated in FIGS, 6-14. Each core 64 has a core print 66
corresponding with each lightener
opening 58, and other opening 60 in the walls 56 of the sideframe 18 may also
have core prints as
illustrated. Each core 64 has an outer surface 68 vfrom which the core prints
66 extend outwardly.
Each core print 66 includes a core print body 70 to be received in a mating
cavity in a mold to
produce the cast metal part. Thus, the core print bodies 70 may serve to
support and properly
position the core in the mold. Each core print body 70 is integral with the
remainder of the core and
is connected to the core outer surface 68 through a bridge or neck 72. Each
bridge or neck 72 has a
thickness, designated "n" in FIG. 11" corresponding with the desired
thicknesses cof the walls 56 of
the cast metal at the edges 62. Each neck or bridge 72 has a circumference or
perimeter that is
spaced inward of the edges 73 of the core print that meet or mate with the
mold surface. Each neck
or bridge 72 forms one of the metal edges 62 in the casting, the inner
circumference of the edge 62
being spaced inward from the juncture of the core print and mold so that any
fin forming at the
juncture of the core print and the mold is spaced fiom the inner circumference
of the edge. Having
such a neck or bridge is expected to be beneficial in ensuring that if a fin
is formed during the
casting process, it should form on the exterior of the casting instead of the
interior, making it much.
simpler to remove the fin through machining or other operation. Moreover, the
hole should not fin
over and should not form on the edges of the openng which could be stressed,
particularly if
damaged during fin removal. In the illustrated embodiment the necks or bridges
72 are concave to
form convex edges 62.
In making such cores, core boxes having cope and drag portions may generally
be used.
Such core boxes are generally separated along a parting line to remove the
formed core therefrom.
To accommodate such removal where the parting line lies in a plane
perpendicular to a plane
through the centers of curvature of the neck or bridge 72, the embodiment
illustrated in FIG. 11
provides a curaed concave neck or bridge with a thickness "n" and with two
aligned centers of
curvature, designated "c," and "cz", each having a radius "r". The two centers
of curvature comprise
circles lying outside or beyond a plane 71 through the junctures of the neck
72 and core print body
70. at the edges 73 of the core prints that meet the mold surface.
Alternatively, the bridge 72 could
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CA 02358077 2001-09-20
have a single center of curvature and a radius of curvature greater than one-
half the thickness of the
bridge °'n". With either embodiment, the core neck or bridge does not
curve back upon itself in a
manner that would interfere with movement of the core relative to the cope and
drag parts of the
core box. Instead, each juncture 73 is spaced a distance '°d" from a
plane 75 thro~~gh. the nearest
aligned centers of curvature c, and c2_ The distance "d" is equal to the
length of the radius of
curvature less the distance x. It should be understood that the present
invention is not limited to
such curvatures; the neck or bridge could alternatively comprise a cylindrical
surface, for example.
At other locations spaced from the parting line, it is not necessary that the
necks or bridges
be curved, have two centers of curvature, or have a radius of curvature of the
neck greater than one-
half the thickness of the neck. Thus, for example, in the cores for forming
the bolster of the present
invention, the radius of curvature for the necks or bridges may be on the
order of one-quarter inch,
with the thickness of the neck, between the outer surface of the core body and
the core print body
being less than about one-half inch to produce a cast metal body having walls
with thicknesses of '
less than about one-half inch.
1 S It may be desirable to vary the thickness of the walls of the sideframe,
as will be understood
by those of skill in the ark, to minimize weight while achieving the desired
strength. In the
illustrated embodiment, the thicknesses of the walls vary, being on the order
of about one-half inch
in some axeas and on the order of about three-quarters of an inch in other
areas. 'f he dimensions of
the necks or bridges vary according to the desired thicknesses.
In the illustrated embodiment the lightener openings in the cast metal
sideframe are slightly
smaller than those shown in U.S. Patent hlo. 5,4$2,986 to move the openings
awr y from the radius
joining the top wall and each sidewall. The illustrated lightener openings 5$
in the top member 24
have widths ranging to a maximum of 3.24 inches. The lengths of the two
lightener openings
nearest the center of the top member are each about six and one-half inches
long; each is spaced
2S from the edge by l.$8 inches and from each other by a distance of about two
inches. The end
lightener hole is spaced 1.62 inches from each edge and does not extend to the
outermost paxt of the
outer pedestal leg 29. Hawever, beading around the openings is removed in
using the wrap-around
prints so that there should not be any weight gain.
1Q
CA 02358077 2001-09-20
Another aspect of the present invention may be seen in FIGS. 6-8, illustrating
the core
consolidation achieved in the method of the present invention. As there shown,
the interior surface
54 of the walls of the sideframe top member, tension member and columns may be
made using four
cores: two one-piece sideframe end cores 80, one one-piece sideframe center
core 82 and one one-
~ piece bottom center core 84.
Each of the illustrated one-piece end cores 80 of the present invention have a
core body 86
with a pedestal portion 88 for defining an interior surface of the sideframe
pedestal 34 at the front
30 or rear 32 end of the sideframe. In the illustrated embodiment, the
pedestal portion 88 defines
the interior surface of the outer pedestal leg 29; the one-piece end core also
defines the interior
I O surface of the pedestal roof 31. An integral diagonal tension arm portion
90 serves to define an
interior surface of the sideframe's diagonal portion 40 of the tension member
36. A top member
portion 92 of the one-piece end core 80 also extends from the pedestal portion
88, and serves to
define the interior surface of the top end 28 and compression member 27
portions of the top member
24. The one-piece end core 80 also includes an iiategral side window support
94 between the
1 ~ diagonal tension arm portion 90, the top portion 92, and a column portion
96. 1'he side window
support 94 serves to define one of the side windows 50 of the sideframe 18,
and as shown in FIG. 9,
is connected to the diagonal tension arm portion 90 and top portion 92 of the
core through necks or
bridges 98 that define the openings 60 in the diagonal portion of the tension
arm ;end underside of
the compression portion 27 of the top member 24. The column portion 96 serves
to define the
20 interior surface 54 of the column 48 of the cast sideframe.
The side window support 94 has flat surfaces 100 that extend outward beyond
floe outer
surface 68 of the core body 86. These flat surfaces 100 serve to support a
part of the weight of the
end care 80 on the mold, and lie in a plane spaced from the outer surface 68
of thr core body 86 a
distance of about one-half inch. Since this surface 100 on the drag side 102
of the core rests on the
25 drag mold surface 103 of the mold cavity 104, and since this surface 100 an
the cope side 106 bears
against the cape mold surface (designated I07 in FIG. 6A for the cope mold
surface at the print 70
on the top member portion 92), this spacing defines the thickness of the metal
to be cast in this area
of the sideframe. In the illustrated embodiment, these surfaces 100 on both
sides 102, 106 of the
core lie in planes.
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CA 02358077 2001-09-20
In the illustrated embodiment, as shown in FIGS. 7 and 9, the side window
support 94 on the
drag side 102 of the end core 80 also includes a locator boss 112 extending
out from the flat support
surface 100. The locator boss 112 is received within a mating hole or opening
11 ~I (FIG. 7A) in the
drag mold surface 103 of the drag side of the mold to locate and support the
core, The illustrated
locator boss 112 has the shape of a frustum of a cone, that is, it has a
slight draft for ease of making
the core and ease of placement of the boss 112 in the mating hole 113. In the
illustrated
embodiment, as shown in FIG. 6, the cope side 106 of the end core does not
have a locator boss,
although it should be understood that a cope side locator boss could be
provided if desired, along
with a mating hole in the cope side of the mold.
Each end care 80 is further, supported on the drag mold surface 103 by the
core prints 66
corresponding with the lightener openings 58 in the outer surface of the top
member 24. Another
core print 118 is located at the bottom center core end 120 of the diagonal
portion of the tension
member. The core print bodies 70 are shaped to be received in mating openings
l 16 in the drag
mold surface 103 and to support a portion of the weight of the end core on the
drug mold surface
and in mating openings 117 in the cope mold surface 107 (FIG. 6A) to stabilize
and position the
core with respect to the cape mold surface. The core prints 66, 118, side
window supports 94 and
locator boss 112 also serve to locate or maintain the position of the end core
80 in the mold during
handling and, in combination with the contour of the mold surfaces 103, 107,
to define the thickness
of the metal to be cast, which may be about one-half inch grade C, B or B+
steel, for example, in the
illustrated embodiment. In addition, the combination of the illustrated core
prints 66, 118 and side
window support 94 can support the entire sideframe end core 80 on the drag
mold surface 103,
without any support chaplets or other device to support or position the core.
The one-piece end cores 80 may be made as a single, integral piece by
providing a core box
knot shown) having cope and drag halves with surfaces defining the shape of
the one-piece end core.
As shown in FIGS. 9 and 10, a one-piece end core made with such a core box
would have a parting
line 130 in the plane of the longitudinal axis 110 of the core but would be
free or joint lines. The
interior surface 54 of a cast metal sideframe or other metal body would
likewise be free frorr~ fans,
joint lines or other type of witness mark other than a slight depression or
witness mark perhaps at
12
CA 02358077 2001-09-20
the parting Iine 130 and at the joints between the consolidated cores. As used
herein, the expression
"witness mark" is intended to be a generic expression encompassing fins and
joint marks.
To facilitate placement of the one-piece end cores 80 in the mold, the
pedestal lug lightener
131 shown in FIG. 15 has been removed from the illustrated one-piece end cores
since the presence
of the lug lightener interferes with automated setting of the core in the
mold. As shown in FIG. 6,
the mold may contain a separate core 217 to define the shape of the pedestal
opening, and the end
core could not be placed in the mold with the core 217 in place if the lug
lightener was retained.
Another feature of the present invention relates to providing a stepped joint
to support and
locate the bottom center core 84 on the two end cores 80, free from any
support chaplets or other
extraneous device for supporting the weight of the sideframe bottom center
core 84. As shown in
FIGS. 8 and 10, the bottom center core end 120 of each diagonal portion of the
tension arm has a
stepped surface. The stepped surfaces on the end cores include a weight
support member 132, a
longitudinal limit member 134 and a lateral limit member 136, all Iying in
different planes. As
shown in FIG. 12, the two ends 138 of the bottom center core 84 have mating
weaght support
members 140, longitudinal limit members 142 and lateral limit members 144, all
comprising
surfaces lying in different planes. In the illustrated embodiment, the weight
support members 132,
140 are substantially co-planar with the longitudinal axis 110 of the end
cores and bottom center
core, although, as will be understood by those in the art, the surfaces 132,
140 and others may have
a draft in accordance with standard foundry practice, and such draft surfaces
are intended to be
w 20 included within the expression °'substantially co-planar" as used
herein. The lonl;itudinal limit
members 134, 142 lie in planes intersecting the longitudinal axis 110 and
intersecaing the planes of
the weight support members 132, 140 and lateral limit members 136, 144. The
mating lateral Iimit
members 136, 144 lie in planes intersecting the planes of the weight support
members 132, I40 and
may comprise a key, designated 137 in the illustrated end core, and keyway,
designated 145 in the
2S illustrated bottom center core; it should be understood that the key could
be forn:ed on the bottom
center core and the keyway on the end core if desired.
As shown in FIGS. 6-8, when the end cores 80 and bottom center core 8~ are
assembled, the
bottom center core weight support members 140 rest on and are supported by the
end core weight
support members 132, and the bottom center core longitudinal limit members 142
and lateral limit
13
CA 02358077 2001-09-20
members 144 are positioned by the end core longitudinal limit members 134 and
lateral limit
members I 36. Thus, the entire weight of the bottom center core 84 is
supported by the end cores 80
on their weight support members 132, 140 and relative movement between the
cores 80, 84 is
limited by the longitudinal 134, 142 and 136, lateral 144 limit members. The
bottom center core 84
has a core print portion 146 at the joint with tlhe end core that mates with
the print 118 at the bottom
center core end 120 of the diagonal part 40 of the tension member 36. Thus,
the bottom center core
may be supported and positioned abave the drag mold surface 103 without
support chaplets, since
the core prints 66, 118, 146 and locator bosses 112 maintain the position of
the end cores 80 and
bottom center core 84, and the mold may be moved and used without the cores
shifting position and
without using support chaplets or other supports or positioning devices.
However, to keep the
bottom center care from floating upward during pouring of the molten metal, it
may be desirable to
place chaplets on top of the bottom center core to bear against the cope mold
surface 107 and
thereby hold the bottom center core down when molten metal is introduced.
As shown in FIGS. 6-?, the junctures of the end cores and bottom center core
are at or
immediately past the curvature points of the tension members 36, that is, the
junctures are along the
diagonal portions 40 of the tension members, near the bottom center portion
40.
As shown in FIGS. 10 and 12-13, the lateral limit surfaces I36, 144 of the key
and keyway
are not perpendicular to the longitudinal limit members I 34, 142, but are
slightly askew so that the
lateral limit surfaces 144 of the bottom center core may be formed
substantially parallel to the
parting line 143 (FIG. 12) of the bottom center core; the lateral limit
surfaces 136, 144 may have a
draft in accordance with standard foundry practices, and such draft surfaces
are intended to be
included within the expression "substantially parallel". This configuration
facilitates removal of the
bottom center core 84 from the core bax.
The bottom center core 84 generally defines the shape of the interior surface
54 of the walls
2S 56 of the bottom center portion 38 of the tension member 36 of the
sideframe I 8. ~penings or slits
I4 7 in the bottom center core, shown in FIG. I2, define internal support ribs
15fl in the bottom
center portion 38 of the tension member 36, as shown in FIGS. 18 and I9. Such
support ribs 150
are shown in FIGS. I8-19 and extend to the spring seat 42 as illustrated, and
correspond with five
spaced slits 147 in the bottom center core 84. In the illustrated embodiment,
all of the slits 14? are
I4
CA 02358077 2001-09-20
defined by spaced walls that Iie in planes substantially parallel to the plane
of the longitudinal axis
149 of the bottom center core 84 for ease of removal of the completed core
from the core box.
It is generally to be expected that a casting made with the disclosed bottom
center cores and
end cores will have an internal witness mark corresponding with the junctions
of or joints 150, 152,
156 between the cores. Because of the stepped surfaces at the joints 150, 152,
156, these witness
marks are longitudinally offset on the interior surfaces 54 of the walls 56 in
the casting. Thus,
considering the two sides of the casting defined by the plane of the
longitudinal centerline 19 of the
cast sideframe 18, shown in FIGS. 18-19, the distances between the witness
marks 152 and the
transverse centerline 154 on one side of the longitudinal centerline I9 of the
sideframe are greater
than the distances between the witness marks 156 and the transverse centerline
1 S4 on the opposite
half of the casting. As shown in FIGS. 18 and 19, a casting having such offset
witness marks 152,
156 can be expected to have been made using cores with stepped surfaces at the
joints between
cores.
A one-piece sideframe center core 82 is illustrated in FIG. 14. This core may
generally be as
described and shown in United States Patent No. 5,481,986, although in the
center care ofthe
embodiment illustrated in the present application, the sideframe center core
82 and bottom center
core 84 are separate elements rather than combined as disclosed in the issued
patent. In addition, in
the embodiment illustrated in FIG. 14, the column faces do not have lightener
openings, but merely
openings for bolts for connecting friction plates to the column faces.
The one-piece sideframe center core 82 of the embodiment illustrated in IjIG.
14 includes a
bolster opening element or portion 158 corresponding with the bolster opening
21 in the cast
sideframe 18. The center care has a central longitudinal axis 1 S~. The
bolster opening portion
includes a pair of planar support print surfaces 160 that lie in planes
substantially parallel to the
longitudinal axis 159 ofthe center core and substantially parallel to the
longitudinal axes 110 of the
end cores 80 when combined with the end cores as shown in FIG. 6. The planar
support print
surfaces 160 may rest on mating support print surfaces of the drag mold
surface 103 to support a
part of the weight of the center core on the mold and prevent molten metal
flow into the area to
become the bolster opening. At the ends of the two planar support print
surfaces 160 are opposite
column surfaces 162 which define the exterior side of the opposing faces 163
of the sideframe
1S
CA 02358077 2001-09-20
columns 48. The core column surfaces 162 are substantially parallel to each
other and have
vertically aligned cylindrical elements 164 extending outwardly from the
surfaces with parallel axes
aligned along the core's longitudinal centerline 159. These cylindrical
elements comprise integral
bolt hole pin cores. As shown in FIG. 6, when the center core 82 is combined
with the two end
cores $0, the cylindrical elements or bolt hole pin cores 164 meet the column
portions 96 of the end
cores to define bolt holes 166 in the opposing faces of the columns 48 of the
cast metal sideframes
for attachment of friction plates to the columns as shown in FIG. 19.
As shown in FIG. 14, the illustrated one-piece sideframe center core 82
includes an integral
spring seat element or portion 170 to define the lower bolster opening 44 and
top surface of the
spring seat 42 in the sideframe. The bottom surface 172 of the spring seat
elemer~~t 170 is spaced
above the bottom center core 84, and together with mating surfaces 174 in the
drag and cope mold
surfaces 103, 107, define a cavity in which metal is cast to form the spring
seat 42 . The spring seat
element 170 also has planar support surfaces 176 which support a part of the
weight of the center
core element 82 on the drag mold surface 103 and mate with the cope mold
surfa~;e 107 to assure
proper positioning of the center core with respect to the mold surfaces.
The illustrated one-piece sideframe center core 82 also includes a top member
center portion
178 that defines the interior surface 54 of the walls S6 comprising the center
portion 26 of the top
member 24. Integral necks or bridges 180 join the top member center portion
178 of the center core
82 to the bolster opening portion 158. The necks or bridges 180 correspond
with openings 182 in
the underside of the center portion 26 of the top member 24, as shown in FIG.
3.
The illustrated one-piece sideframe center core 82 may be made as a single
integral piece by
providing a core box with cope and drag portions surfaces defining the shape
of the center core.
The core may be made so that the longitudinal axis 159 comprises the parting
lin,r of the core box,
with the resulting core being free from joints and having only a parting line
184 along its central
longitudinal axis 159. To produce any indentations or protrusions in the core
body that could be
damaged during removal from the core box, the core box may be provided with
movable parts that
can be retracted when the core is to be removed firam the core box. Such a
core box is illustrated in
FIG. 40. Automatic devices, such as pneumatic or hydraulic operated elements,
may be used with
the core boxes to move the movable parts as desired during the cycle. The core
produced may only
16
CA 02358077 2001-09-20
have a visible parting line on a portion of the core, such as along the
central longitudinal axis 159 of
the top member center portion 178 and necks or bridges 180 but not elsewhere.
A cast metal sideframe made using the illustrated sideframe center core 82 may
be expected
to have witness marks comprising either joint lines or fins 186 on the
interior surface 54 of the walls
S6 comprising the top member 24, as shown in FIGS. 18 and 19, where the center
core top member
center portion 178 portion meets the end core top member portions 92, as shown
in FIGS. 6-8, but
to be otherwise free of joint lines or fins in the areas of the sideframe
defined by the center core 82.
In addition, the center core 82 may be supported on the drag mold surface 103
solely by the support
surfaces 160, 176 so that the cast metal in the area of the sidefrarne defined
by the one-piece center
core 82 has fewer chaplets; since there are no support chaplets, one side of
the tension member
bottom center 40 may be free from support chaplets, while the other side may
have some locatian
chaplets.
The one-piece sideframe center core 82 may also have gates 161 in the bolster
opening
element or portion 158, for movement of molten metal as will be understood by
those in the art.
The illustrated gates are included for purposes of illustration only and, if
included, should be sized,
shaped and positioned according to standard casting practices.
A cast metal sideframe made using the four illustrated cores 80, 82, 84 may be
expected to
have witness marks 186 on the interior surface 54 of the walls 56 comprising
the top member 24, as
shown in FIGS. 17 and I8, and the offset interior witness marks 152, 156 in
the tension member 36,
but the interior surface should be otherwise free of joint lines and fins in
the areas of the sidefrarne
defined by the center core 82 a
The advantages of using two such one-piece end cores 80, one-piece center core
82 and one-
piece bottom center core 84 can be seen from a comparison of the number of
cores used in the prior
art to produce the interior cavity of a sideframe. Prior art cores are
illustrated in hIGS. 15-17. FIG.
15 shaws a typical prior art core arrangement for making an end of a
sideframe; seven cores were
needed to form each end of the sideframe, for a total of fourteen cores,
compared to a total of two
cores in the present invention. The ,prior art cores for the sideframe end
included: cope and drag
side frame window cores 190, 192 to form the area of the side window 50 and
column 48 interior;
cope and drag side frame intermediate cores 194, 196 to form a part of the top
member and pedestal
17
CA 02358077 2001-09-20
roof interior; cope and drag sideframe tension cores 198, 200 to form the
diagonal portions 40 of the
tension member 36; and an end core 202 to form the interior of a part of the
pedestal 34. These
cores were not integral, but were juxtaposed or sometimes adhered together,
with joint lines existing
between each of the individual cares. This substantial number of cores used in
the prior art has been
problematic in several respects: automation of the process of setting the
cores in the mold is difficult
since there are several small pieces that need to fit together in the mold;
and there could be quality
control problems with the prior art cores: shifts and movements of the
individual cores or
imperfections in the fit between adjoining cores could produce interior fins
during casting or could
result in the varying thicknesses of the casting walls; and if two cores such
as the cores 198, 200 are
not properly aligned, the metal casting may have a stepped or uneven surface
at the juncture of the
two parts. Multiple cores are often thin, requiring use of core rods to
provide strength to the core.
Removal of these core rods after the casting is formed adds to the cost of
manufacture.
Similar disadvantages and problems arise in using the multiple cores for the
prior art center
portion of the sideframe. As shaven in FIGS. 16-17, one example of prier art
center cores generally
required at least nine cores where the present invention provides two: a side
frame bolster opening
core 204, four column pin cares 206 inserted into the bolster opening core, a
spring seat core 208
and cope and drag bottom center cores 210, 212 adhered together. The prier art
aalsa typically
included a spring seat back up care {not shown) that was not integral with or
adhered to another
care.
2p It should be understood that several additional cares are required for
adding various
appendages to the sideframe although these ether cores will not be addressed
by this invention. For
example, there may be separate rotation lug cores added to the center core,
although such cores
could also be consolidated into the sideframe center core. Moreover, an
additional six cores (not
shown) may be required in the manufacturing process. But even with these
addi~ional cores, the
present invention consolidates twenty-three cores into four, reducing the
total number of cares for
making a sideframe from twenty-nine to ten. These additional cares may need
tc~ be supported by
chaplets on the drag mold surface, and may require locator chaplets to secure
their positions. Some
of these additional cores that are used with the present invention are
generally shown in FIG.6,
including the right and left journal cores 217 and right and left journal
bracket cores 219. In
18
CA 02358077 2001-09-20
addition, bracket cores to form slots for brake beams on the inboard sides of
the sideframes would
still be used, and the right and left journal cores, right and left journal
bracket cores and brake beam
bracket cores may require use of weight-supporting or locating chaplets, so
that the resulting
sideframe would have some chaplets, although the number of chaplets and the
problems associates
with their use is greatly decreased with the present invention.
Thus, it can be seen that the present invention offers several advantages in
making
sideframes. By reducing the number of cores, any tendency for shifting of the
multiple cores is
reduced, reducing internal metal mismatches. The safeguard against shifting is
enhanced in the
present invention by the use of the locator bosses 112 on the end cores 80 and
the stepped
connections between the bottom center core 84 and the end cores that limit
lateral and longitudinal
movement. Similarly, the fit of the core prints 66 of the end cores in the
mating areas of the cope
and drag mold also stabilize the positions of the end cores and bottom center
core. .And since the
four cores of the present invention are supported in the mold by the core
prints, other cores and
opening-defining parts, the castings can be made without support chaplets,
increasing the efficiency
I S of the manufacturing operation and minimizing the chance for shifting of
the corns. In addition, the
present invention minimizes the number of joint lines which normally result
between the faces of
multiple cores, to improve the appearance of the final casting, reducing the
amount of preparatory or
finishing work necessary to remove fins, and improving internal casting
quality by eliminating or
greatly reducing the potential for stress risers which tend to form along the
entire joint line. And
since the manpower required for proper placement of the four cores instead of
tw~nt~-three is
substantially less, labor costs should be reduced. With fewer and larger
cores, there is also a chance
for automation of the assembly process. Moreover, as will be understood by
those in the casting
field, the tooling costs in creating a single mold, as well as the replacement
and maintenance costs
for retaining quality standards for each mold is substantial. It is expected
that waste of mold sand
will also be reduced with fewer cores being produced, further reducing costs.
In addition, it is
expected that with fewer cores and less relative motion between cores, there
is a Power potential for
sand particles to become dislodged and become inclusions in the finally-cast
metal. Inclusions can
potentially become stress concentration areas or simply result in an area on
the casting that requires
19
CA 02358077 2001-09-20
surface clean up. Another advantage of the present invention is in eliminating
or reducing the need
to use core rods to strengthen the cores, simplifying production and reducing
costs.
Another advantage of the present invention is in the assurance of proper
placement and
alignment of core pieces. In the case of the one-piece center core 82, the
vertically aligned
cylindrical elements 164 take the place of the column pin cores 206. The
column pin cares 206
have typically been inserted into the surface of the side frame bolster
opening core 204 after the
cores 204, 206 have been formed, and there has been a potential for
misalignment of the pin cores,
resulting in bolt holes 166 in the final casting that may be angled, making it
more difficult to insert a
bolt through the hole. With the integral cylindrical elements 364, the
resulting bolt holes should
always be properly aligned.
Another feature of the present invention relates to provision of a pair of
radial drafts 220 on
the end core column portions 96 as shown in FIG. 9. As illustrated in FIG. 20,
the facing exterior
faces 163 of the columns 48 typically have bolt holes 166 for mounting
friction plates 222 to the
sideframe with bolts 224. As shown in FIG. 21., washers 226 and nuts 228 are
tightened against the
1 S interior surface S4 of the column portion of the sideframe. If the
interior surface ~4 of the column is
uneven, irregular or offset, then less than the entire flange of the nut or
washer co~~tacts the surface
54; during tightening, stresses could be concentrated at portions of the nut,
resulting in breaking or
bending of the nut or bolt, or a less than desirable clamping force holding
the plates 222 in place.
This problem could potentially occur in one-piece end cores having parting
lines ~urming through
the bolt hole areas, as well as in mufti-piece cores having separate cores
adhered t.o or juxtaposed
with each other at junctures or joints intersecting the bolt hole areas. To
alleviate this potential
problem, the present invention provides a pair of conical raised areas 220 on
the column portions 96
of the end cores 80. As shown in FIG. 9, each raised area 220 comprises a
raised center 230
extending furthest out from the outer surface 68 of the surrounding planar
face 2 32 of the column
portion 96 core. Each raised area also includes a tapered surface 234
extending from the raised
center 230 toward the outer surface 68 cjf the planar face 232. The raised
area has a circular outer
peripher;~ 235 that is spaced slightly above the planar face 232. The outer
diameter of each raised
axea is about two and one-half inches. The tapered surface 234 and center 230
are shaped as a cone.
The angle of the illustrated tapered surface is small, being on the order of
one-third to one-half
CA 02358077 2001-09-20
degree. In the illustrated embodiment, there are two vertically-aligned raised
areas 220, and the
parting line 110 of the core runs through the raised centers 230 of the two
raised areas. When
placed in the mold along with the other cores, the center of each raised area
230 of each end core
contacts the free end of one of the vertically aligned cylindrical elements
I64 to define the bolt
holes 166 in the casting. Thus, as shown in FIG. 21, each bolt hole 166 in the
casting is surrounded
by a depression 236 in the interior 54 surface of the casting. The depression
236 has a circular edge
238 at or slightly below the interior surface 54 of the casting, and a tapered
wall 240 extending
between the edge 238 and the bolt hole 166 at the center of the depression. In
use, the peripheral
edge of the nut 228 or washer 226 should contact the tapered wall 240 of the
depression around the
entire circumference or perimeter of the nut or washer. Since the entire
circumference of the nut or
washer is in contact with the interior surface of the side frame, there should
be no bending moment
on the nut and no lessening of the clamping force or torque. Instead, use of
the present invention
should result in symmetrical loading of the washer and nut. It should be
understood that the
principle of this feature of the invention should be applicable to any setting
wherf: a bolted
connection is to be made where there is also a core or mold parting or joint
line intersecting the site
for the bolted connection. It should also be understood that the slope of the
tapered surfaces of the
core raised area and casting may generally be relatively small.
Many of the above principles can be applied to improve hollow cast metal
bolsters 20 as
well. As shown in FIGS. 30-31, a bolster 20 can be made with three
consolidated coxes defining its
interior: a ane-piece center core 300 and two one-piece end cores 302
supported ~Jn the center core
300. Other standard cores, such as two spring cores, four pocket cores and a
top center pin core,
would still be required to be used to complete the bolster.
The bolster 20, as shown in FIGS. 23 and 24, has a center 304, two outboard
ends 306, a top
wall 308, and parallel side walls 310 extending down from the top wall 308.
Each illustrated side
wall 310 has four large, spaced holes 3I2, and each hole has an overall length
and width. The
bolster has an interior and the top wall 308 has ar~. interior surface 314 and
an exterior surface 316.
The. side walls 310 also have interior surfaces 3I8 and exterior surfaces 320.
The bolster 20 has a
central longitudinal axis or plane 322 running from one outboard end 306 to
the opposite one, and a
perpendicular central transverse axis or plane 324. The bolster 20 also has a
bottom wall 326 and
21
CA 02358077 2001-09-20
interior walls 328. The bottom wall 326 in the illustrated embodiment extends
between the
sidewalk 310, and carA have openings or holes (not shown) communicating with
the interior of the
bolster.
The bolster 20 also has a center bore 330 through the top wall 308. The
central longitudinal
axis or plane 322 and central transverse axis or plane 324 intersect at the
center bore 330. Two sets
of bolt holes 331 are provided for mounting side bearings to the bolsters.
Within the interior of the illustrated embodiment of a bolster, there are
longitudinal ribs 328
extending longitudinally between the interior surface 314 of the top wall 308
and the bottom wall
326, and transverse support ribs 334 extending transversely between the
longitudinal ribs 328.
As shown in FIGS. 23-24, each longitudinal rib 328 has opposite faces 336,
338, and each
transverse rib 334 has opposite faces 340, 342. In the illustrated embodiment,
at least one of each
pair of faces 336, 338, 340, 342 is generally perpendicular to the plane of
the top wall 308 of the
bolster and remains generally perpendicular to that wall throughout its entire
height. Similarly, the
faces 340, 342 of the illustrated transverse ribs 334 are generally parallel
to the transverse axis or
IS plane 324 throughout their entire height, from the interior surface 314 of
the top wall 308 to the
interior surface 344 of the bottom wall 326. At least one of the opposite
faces 336, 338 of the
longitudinal ribs 328 is generally parallel to the central longitudinal axis
or plane 322 throughout its
entire length. At least one of the illustrated opposite faces 336, 338, 340,
342 of ~:he longitudinal
ribs 328 and transverse ribs 334 is generally vertical throughout its entire
length.
In contrast, in the prior art bolster illustrated in FIG. 22, the transverse
support ribs 346 had
faces 348, 350 that were both angled throughout a portion of their heights.
These faces 348, 350
were both in non-vertical planes that intersected the vertical plane of the
central transverse axis 324.
These angled transverse ribs 346 prohibited making a one-piece center core for
the bolster, since
such a core could not be removed from the core box without damage to the core.
Instead, multiple
cores, as shown in FIG. 28, were needed to produce the central portion of the
bolster.
In this aspect of the present invention, all of the interior transverse rib
faces have been
aligned to allow a one-piece core to be made and used without sacrificing the
desired physical
characteristics of the bolster. Although the interior ribs may thin or thicken
bet~-een the top and
bottom walls, the change is on one side of the parting line for the one piece
core, and only one face
22
CA 02358077 2001-09-20
of the wall changes direction on that side of the parting line. And while the
interior ribs made with
a one piece core may have draft faces, on each side of the parting line the
faces do not diverge from
a vertical plane in the same direction., Thus, as shown in FIGS. 23 and 23A,
in the top portion 33?
of the bolster, from the top wall 308 down, the faces 336, 338, 340, 342 of
the longitudinal and
transverse ribs do not diverge in the same direction from a vertical plane 341
between them and
parallel to one of the longitudinal or transverse axes or planes 322, 324, and
in the bottom portion
339 of the bolster, up from the bottom wall 326 to the top portion, the faces
336, 338, 340, 342 of
the longitudinal and transverse ribs do not diverge in the same direction from
a vertical plane
between them and parallel to one of the longitudinal or transverse axes or
planes 322, 324. The top
and bottom portions 337, 339 are defined by a line 343, shown in FIG. 23A,
corresponding with the
parting line 406 of the center core used to make the bolster, shown in FIG.
30.
The multiple prior art cores needed to produce a prior art bolster are
illustrated in FIGS. 25-
29. As shown in FIG. 29, two sets of cope and drag end cores 360, 362 were
reduired to make the
central part of the bolster, joined along a joint line 364. Right and left
collar core 366, shown in
1~ FIG. 2j, were needed to form the center bowl or plate 368 {shown in FIG.
22). An additional lug
core 370, shown in FIG. 26, was used to form lug holes in the side wall for
attachment of a brake
beam dead lever lug to the bolster. Two sets of cope 372 and drag 374 center
cars, shown in FIG.
28. These center cores 372, 374 were also joined along joint lines 376. As in
the case of the
sideframe cores, these cores were supported on the drag mold surface by
chaplets. Thus, there was
a potential for shifting of the cores, and control of the thicknesses of th.e
metal walls became
problematic. In addition, with all of the joint lines, there was a potential
for stress risers to form in
the casting.
As shown in FIG. 27, the prior art also used four separate pin cores 378 to be
attached to the
cope parts 360 of the end cores to form hales 331 for attachment of side
bearings to the bolster.
There was the potential for the pin cores 378 to be attached off axis,
creating the potential for
undesirable stress on the bolts for attaching the side bearings to the
bolsters.
In this aspect of the present invention, these sixteen prior art cores have
been consolidated
into three cores, shown in FIGS. 30-39. In both the embodiments of FIGS. 32
and 33, the one-piece
center core 300 has a center core body 380 to be received in a mold cavity for
defining the interior
23
CA 02358077 2001-09-20
surfaces 314, 318, 344 of parts of the top 308, side 31 U and bottom 326 walls
of the bolster, as well
as parts of the longitudinal ribs 328 and transverse ribs 334. The center core
body 380 has a central
longitudinal axis 382 and a central transverse a,~cis 383, as well as outer
surfaces 384 to define the
interior surface 318 of the sidewalk 310. Outboard of the outer surfaces 384
are two core prints
386. The core prints 386 are integral with the center core body 380, and serve
to support and
position the center core in the drag mold 387 so that no support chaplets are
reduired. The inner
surfaces 455 of the core prints (FIGS. 34, 35) also serve to define a portion
of the exterior surfaces
320 of the bolster sidewalls 310. Spaced surfaces 381 (FIG. 39) in the
receiving mold also define
portions of the exterior surfaces of these sidewalk. The core pxints 386 are
connected to the center
core body 380 through necks or bridges 388 corresponding in size, shape and
position with the holes
312 in the sidewalk.
T'he center core body 380 and center core prints 386 have lengths sufficient
to span across
the widths of all of the necks or bridges 388 on one side of the center core
body. The center core
prints 386 have heights su~cient to span across the heights of all the necks
or bridges 388 on the
1 S center core body 380. In the illustrated embodiments, the core print
heights are also great enough to
extend to a pair of holes 390 (FIGS. 31-33) in the print and aligned with
holes in the core body 380
to receive cylindrical cores to define the dead lever lug holes. 'fhe heights
of the core prints vary
with the heights of the adjacent necks or bridges across the lengths of the
core prints.
As shown, each embodiment of the core prints 386 has a central zone 392 and
two end zones
394. The central zone 392 and end zones 394 have stepped top surfaces 396 and
stepped bottom
surfaces 398, and the heights of the central zones 392 of both embodiments are
greater than the
heights of the end zones 394.
The central zones 392 of both core prints 386 have a height great enough and
are wide
enough to form part of the center plate or bowl 393 (FIGS. 23, 24) of the
bolster. As shown, the
center plate forming parts 400 are integral with the core prints 3 86. At the
core prints' end zones
394, the top surfaces 396 and bottom surfaces 398 are stepped toward each
other, away from the tap
and bottom surfaces at the central zone. The top surface 396 may have also two
steps, as shown in
FIG. 33, or a single step as shown in FIG. 32. In either embodiment the
different levels of the top
and bottom surfaces may be joined by angled or draft surfaces 402 that ease
removal of the bolster
24
CA 02358077 2001-09-20
center core from the core box. The drag 387 and cope 403 mold surfaces are
formed to have
recesses that mate with the shapes of the care prints so that the core prints
may be easily placed in
the mold.
The bottom surfaces 398 of the core prints 386 comprise weight support
surfaces parallel
with the top surfaces of the core prints. The total surface areas of the two
weight support surfaces of
the core prints and mating surfaces of the drag mold surface are great enough
to support the entire
center core on the drag mold surface 387 free from support chaplets. The
weight support surfaces
lie in planes that intersect the longitudinal axis 382 of the center core. The
draft surfaces 402 of the
core prints and mating surfaces of the cope mold may comprise positioning
surfaces that lie in
planes intersecting the top surfaces and bottom surfaces 396, 398 of the core
prints. The draft
surfaces 402 may thus serve to limit longitudinal movement of the core body
380 in the mold. The
end faces 407 of the core prints, received against mating faces in the drag
mold, may also serve to
limit longitudinal movement of the center core. The outer surfaces 404 of the
core prints and
mating surfaces in the drag mold perpendicular to the top 396, bottom 398 and
draft 402 surfaces
may control lateral movement of the center core with respect to the drag mold
portion 387.
The one-piece center core 300 is free from joint lines, but has a parting line
406 with
segments that intersect the vertical plane of the central transverse axis 382,
383. The center core
body 380 has a top portion 408 on one side of the parting line 406 and a
bottom laortion 409 on the
opposite side of the parting line 406. As shown in FIGS. 32 and 33, the
parting line 406 does not
intersect the end faces 407 of the core, since it is preferred that the end
faces 407 not have a draft
above the parting line that would create a gap in the mold. Instead, the
parting line goes to the top
surface 396 of the end zone at the end face 407 and then. down again.
The center core body 380 has a plurality of interior surfaces 412, with pairs
of them spaced
apart to define slits far forming the longitudinal ribs 328 and transverse
ribs 334 of the bolster 20.
As shown in FIGS. 34 and 35, to facilitate removal of the core from the core
box., no two adjacent
surfaces on one side of the parting line 406 diverge from a vertical plane
parallel to the transverse or
longitudinal axis 382, 383 in the same direction; this design allows the core
to bc: made in one-piece
with a cope and drag core box pulled apart on the parting line 406.
CA 02358077 2001-09-20
As will be understood by those in the art, the interior surfaces 412 of the
bolster center core
rnay have drafts to facilitate removal of the core from the core box. However,
the core will not have
pack drafts that would be damaged in removing the core from the care box if,
as shown in FIG.
3SA, no two adjacent surfaces 412 on one side of the parting line 406 diverge
in the same direction
from a vertical plane 401 between them and parallel to one of the longitudinal
or transverse axes
3 82, 3 83 of the core.
The necks or bridges 388 connecting the core body and the core prints 386 may
be concave
curves, like the necks or bridges for the embodiment of the sideframe end
cores illustrated in FIG.
11, so that the resulting bolster has convex surfaces at the edges surrounding
the holes 312. As in
the sideframe end cores, as shown in FIG. 35 the bolster core necks 388 may
comprise inwardly
curved surfaces with one or more centers of curvature designated "c" lying in
a line around the
exterior of the neck or bridge, beyond the junctures 411 of the necks and
prints, as in FIG. 11
embodiment for the sideframe. As in the sideframes, the thicknesses of the
necks 388 correspond
with the desired thickness of the walls of the cast bolster in that area. As
in the sideframe, the
l S radius of curvature may be greater than or equal to one-half the thickness
of the neck or bridge. In
the illustrated embodiment, the radius of curvature of the necks is less than
one-half the thickness
"n" of the necks, being about three-sixteenths of an inch for a metal
thickness of one-half inch to
meet the adjoining draft surfaces of the core print interior 45S and core body
exteaor 384.
As shown in FIG. 22A, prior art bolsters frequently used a flat raised
mounting area 457 on
the exterior of the sidewali 461 for mounting a dead lever lug 463 to the
bolster. Such flat raised
mounting areas have provided a level mounting for the dead Iever lugs, that
is, for the mounting
bracket for the railcar braking mechanism, in an area where the sidewall is
angled. However, to
provide such a flat raised mounting area on a bolster made with a one-piece
center core is
problematic: to avoid creating a step which would prohibit removing the one
piece core from the
2S core box, the mounting area would have to extend to the parting line, but
this would add to the
weight of the casting. Instead, in the present invention. the area of the
bolster sidewall 310 where
the dead lever lug is to be mounted does not have a flat mounting area; the
area of the bolster
sidewall is instead angled, as seen in FIG. 24, and the dead lever lug is
similarly angled for
mounting on the bolster sidewall, as shown in FIGS. 41 and 42.
26
CA 02358077 2001-09-20
As shown in FIG. 24, the bolster side wall 310 has non-parallel portions
4<'.1, 423, 425
meeting along junctures 427, 441 defined by radii.
As shown in FIGS. 41 and 42, a dead lever lug 413 for use with the illustrated
bolster has
two arms 415, 417 with mounting surfaces 443, 445 angled to mate with the one
c~f the non-parallel
portions of the bolster side wall; that is, the angle between the mounting
surfaces 4.43, 445 mates
with the angle between two portions 42I, 423 of the bolster sidewall. The
mounting surfaces 443,
445 of the illustrated dead lever lug arms 415, 417 are spaced apart with a
gap 419 between them.
The gap 419 spans one radius at one juncture 427 on the bolster sidewall 310
where the sidewall is
angled; that is, the gap 419 overlies one juncture 427 of two non-parallel
portions 421, 423 of the
bolster side wall. The arms 415, 417 may also be angled in another direction
to mate with any draft
in the sidewall.
The two mounting surfaces 443, 445 are on the mounting side 447 of the dead
lever lug, that
is, the side that faces the bolster side wall 310 when mounted on the bolster.
A third surface 449 is
in the gap 419 between the mounting surfaces 443, 445. As shown in FIG. 41,
th:~ three surfaces
443, 445, 449 all lie in different planes, and the mounting surfaces 443, 445
lie in intersecting
planes.
In another aspect, the one-piece center core 300 for the bolster may have two
stepped
outboard ends 414, 416 opposite from the transverse center line 383 for
supporting the end cores
302. Each of the two outboard ends 414, 416 of the bolster has a weight
support member 418, a
longitudinal limit member 420, and a lateral limit member 422 all lying in
different planes. As
shown in FIGS. 30 and 35-36, the two inboard ends 424 of the end cores 302
have mating weight
support members 426, longitudinal limit members 428 and lateral limit members
430, all
comprising surfaces lying in different planes. In the illustrated embodiment,
the weight support
members or surfaces 418, 426 are perpendicular to the planes of the
longitudinal axis 382 of the
core body. The mating longitudinal limit members 420, 428 lie in planes
paralleto the plane of the
transverse center iine 383 and the mating lateral limit members 422, 430 lie
in planes parallel to tl'~e
longitudinal axis 382 of the care body. The mating lateral limit members 422,
4.30 may comprise a
key at each end 414, 416 of the center core and a mating keyway in the ends
424 of the end cores, as
shown in FIGS. 31-34 and 36-37.
27
CA 02358077 2001-09-20
As shown in FIGS. 30-31 and 38, when the three cores 300, 302 are assembled
the interior
or inboard ends 424 of the end cores 302 are supported by the outboard ends
414, 416 of the one-
piece center core 3U0. Each end core 302 also has an outboard end 432 that
rests on and is supported
by a part of the drag mold surface 387 when the three cores are placed in a
mold. The drag mold
387 and outboard ends 432 of the end cores may have mating surfaces to ensure
proper placement
of the cores in the mold and the cope mold may also have mating surfaces to
stabilize the positions
of the outboard ends 432 of the two end cores. As shown in FIG. 38, gating or
gas relief cores 433
may also be provided at the outboard ends 432 of the end cores. With the end
cores 302 thus
supported and the center core 300 supported solely by the core prints 386, all
three cores may be
supported above the drag mold surface free from support chaplets. In the
illustrated embodiment,
the tap surfaces 396 of the end zones 394 are flush with the top surface 431
of the drag mold 387 so
that the bottom surface of the cope mold may bear against the end zones 396
and hold down the
core.
The end cores 302 may each be a one-piece integral core free from joint lines
as illustrated
in FIGS. 36 and 37. The end cores may have recessed areas 434 for forming the
parts of the bolsters
that ride on friction shoes on the sideframes; and as will be understood by
those skilled in the art,
the shape of the end cores will vary with the type of friction shoe to be
used. As shown in FIG. 38,
mating friction shoe cores 43 S may be pravided on the drag mold surface. In
addition, as shown in
FIG. 38, a center pin care 429 may also be provided at the center of the
bolster center core. In each
2U end core, parallel interior surfaces 436 define a central slit 438 along a
central longitudinal axis 439
for forming one of the longitudinal ribs 328 of the bolster. Additional slits
437 a~~e formed by
parallel surfaces 439 at the inboard ends 424 of the end cares 302 and align
with interior surfaces
412 of the bolster center core to form two additional longitudinal ribs 328.
Each end core 302 may
have a parting line 440 but is free from any' joint line.
2S Each end core 302 also has a pair of integral bolt hole cylinders 442
extending upwardly
from the top surface 444 of the end core. The bolt hole cylinders are aligned
transversely near the
stepped inboard ends 424 of the end cores to provide the holes 331 for bolts
for rlounting side
bearings to the bolster.
28
CA 02358077 2001-09-20
A bolster resulting from using the three cores of this aspect of the present
invention can be
expected to have a minimum number of interior fins or joint lines. The only
interior fins or joint
lines can be expected to be along the junctures of the center core 300 and end
cores 302. Any such
fm or joint line is referred to herein generically as a witness mark. As shown
in F1G. 23, there may
be a pair of top witness marks 446 on the interior surface 314 of the top wall
308, parts of the top
witness marks 446 being perpendicular to the longitudinal axis 322, part
matching the shape of the
key and keyway, and positioned between the center bore 330 and the side
bearing bolt holes 331.
The interior surface 318 of each side wall 310 may have a pair of side witness
marks 448 leading
from the ends of the top witness marks 446 to the bottom wall 326 interior
surface; 344. Each of the
side witness marks 448 comprises a step-shaped line having a segment 450
parallr~l to the top wall
interior surface 314 between two segments 452 perpendicular to the top wall
interior surface 314. A
pair of spaced straight bottom witness marks 454 may extend across the
interior surface 344 of the
bottom wall 326 between the side witness marks 448 on opposite side walls. All
of the witness
marks correspond with the junctures of the mating ends 414, 416, 424 of the
center core 300 and
1~ two end cores 302. The interior surfaces of the walls of the bolster are
otherwise free from joint
lines and fins. AlI of the walls of the bolster may be expected to be free
from support chaplets,
although there may be chaplets to prevent flotation of the end cores during
casting, and possibly to
position a center core farming the center bore 330.
The exterior sidewalls 310 of a bolster made in accordance with this part of
the disclosure is
defined in paxt by the interior surfaces 45~ c>f the center core prints (FIGS.
34, 35) and may be
expected to bear some imprint of the perimeters of the core prints 386 on the
exterior surfaces 320
of the side walls 310. Thus, the elongated "plus" sign shape of the core
prints 386 may be visible on
the exterior of the casting as a witness mark.
The cares described above may be used to produce cast metal sideframes and
bolsters by
2~ placing the cores in suitable drag molds formed of green sand or other
material ire the drag side of a
flask. A suitable cope side of a flask may tl'~en be placed on the combination
of the cores and drag
flask.
For the sideframes, chaplets may be used to prevent floatation of the bottom
center core and
to support and locate other cores, such as the cores used to form recesses on
the inboard sides of the
29
CA 02358077 2001-09-20
sideframes to receive the ends of brake beams, the journal cores and other
cores to cooperate with
the ane-piece end cores to form the complete pedestals 34. Such other cores
are illustrated
generally in FIG. 6, showing the four cores of the present invention in
position in a drag flask; the
details of the other cores are not shown, as those cores may be made and used
accoxding to the prior
art.
For the bolster, the one-piece bolster center core 300 may be supported
against movement in
all three directions without chaplets, being supported by the mating mold
halves and core prints.
Each of the two bolster end cores 302 may be supported at one end by the
stepped and keyed joint
with the center core, and the other end supported by the drag mold. While the
bolster end cores do
not need support chaplets, floatation chaplets may be provided to hold the end
cores down during
pouring. Pouring and venting areas will be provided according to standard
foundry practices.
The combinations may be handled as has been done traditionally in the art:,
and in fact may
be moved with a reduced chance for the cores to shift position. Molten metal
may be introduced as
has been done in the past. After the metal has cooled, the casting may be
removed from the flask,
and the cores may be removed from the flask using known methods, such as by
shaking the casting.
The casting may then be finished, either as has been done traditionally in
metal casting operations
or the finishing operation may be automated sincE~ any fins will have been
moved to the exterior of
the casting. The present invention includes d1e method of making cast steel
sideframes, bolsters,
and other cast metal bodies in accordance with. known foundry principles,
using the new cores as
described, and preferably without support chaplets for the one-piece cores.
Standard grades of steel
for such products may be used in these processes..
The cores may generally be made in accordance with standard foundry practices.
Generally,
cope and drag core box pardons may be provided, and if automated equipment,
such as a blower, is
used to fill the core boxes, the cope and drag portions may be provided with a
plurality of vents for
air escape during filling. The sand used to make the cores may be mixed with a
known binding
agent. A suitable binder system a available from the Foundry Products
Division, Ashland
Chemical Company division of Ashland Oil, Inc. of Columbus, Ohio. The binder
is sold under the
trademark "ISOCURE" and comprises two resins: a first part with having
phenolformadehyde
polymer blended with solvents and a second part having polymeric MDI
(methylene bis-
CA 02358077 2001-09-20
phenylisocyanate). The two liquid resins cure to a solid urethane resin.
Generally, the phenolic
resin first part combines with the polyisocyanate second part in the presence
of an amine catalyst
(tr~iethylamine) to form the solid urethane. Mixing the resins with the sand
should be as
recommended by the manufacturer, and should follow standard practices, taking
into account the
quality of the original sand, whether the sand is fresh or recycled, and other
factors. The bindex
ratio and hinder percentage may be adjusted as recommended by the
manufacturer. The core boxes
for producing the cores may have vents placed and sized as recommended by the
manufacturer. It
should be understood that the present invention is not limited to any
particular binder system, nor to
any particular core box design or device for introducing the sand and binder
mixture into the core
1 d boxes.
Standard industry practices for introducing the mixture of sand and binder may
be used,
including but not limited to blowing. As will be understood by those skilled
in the art, any suitable
commercially available equipment may be used for introducing the mixture and
curing agent, if any,
as well as any improvement in presently available equipment. The equipment
should be
I 5 compatible with the binder system, but otherwise the selection of
equipment may vary depending on
desired production schedules.
For the blower device used, the blow tube size and position will vary with the
care. Blow
tubes may be located above the deepest and heaviest sections of the core, with
bla~w tube diameters
varying in accordance with standard practice. A blow plate for the center core
~~may have a
20 plurality of conduits with rubber ends for introducing the sand and binder
mi;cture into the core box.
The cope and drag portions of the core boxes will have vent areas through
whirl;, air may escape as
the sand and binder mixture is blown into the core box and through which the
catalyst gas may
escape. The position, number and areas of the vents should be according to
standard practice and as
recommended by the manufacturers ar suppliers of the binder and catalyst and
blower equipment.
25 In making a one-piece core such as the illustrated one-piece center core 82
far the sideframe,
traditional cope and drag core boxes may not produce the desired design that
has recesses or
protrusions that would interfere with pulling the two core box halves apart
and removing the core.
With such cores, it may be necessary to use a core box such as the drag
portion illustrated in FIG.
40. As there shown, the core drag box 459 has movable walls 460, 462, 464 that
may be moved
31
CA 02358077 2001-09-20
inward during core production and then pulled outward during core removal, and
a stationary wall
466 that is part of the drag. Thus, features such as the vertically-aligned
cylindrical elements 164
may be formed by cylindrical recesses 468 in the movable side walls 460, 464
and pulled out of the
way when the completed core is to be removed from the box. Instead of moving
the entire wall, it
may also be desirable to have portions that move at different times during
production. The walls or
portions of walls may be moved by devices such as a pneumatic control 470; in
the illustrated
embodiment, two pneumatic controls are provided, with lines 472 connected to
power the controls
470 to move the walls 460, 462, 464 or portions of walls. Recesses in the core
box walls may be
provided with vents 473, and as will be understood by those in the art, any
equipment used to
introduce the sand and binder mixture into the core box should be designed to
ensure that all parts
of the core box are filled with the sand and binder mixture. Some movable
parts may also be
needed in producing the one-piece bolster center core with holes; axially
movable cylinders may be
used to produce the holes 390 through the prints and later filled with
cylindrical cores.
The one-piece cores produced in accordance with the principles disclosed
herein may be
expected to weigh a substantial amount and accordingly be difficult for a
single ~rorker to
manipulate. Accordingly, it may be desirable to provide for automation in
removing the cores from
the core box and in transporting the cores. In addition, pallets may be
provided tcp support the cores.
Picker fingers or lift devices may be incorporated into the core box design to
lift the core out of the
box, and gantries may be provided for standard moving devices to lift and move
the cores. The core
designs may be modified to accommodate the particular lifting and moving
devices and pallets to
avoid damage to the surfaces of the core bodies. For example, it may be
desirablzw to make the core
prints large enough for a lifting or supporting device to bear against several
portions of the cores
instead of acting against the core body itself. And it may also be desirable
to provide orifices or
recesses in the core prints and core bodies to receive lifting devices for
moving the cores as well as
2a to lighten the cores and reduce the amount of sand and binder required to
be used. As with. the
lifting devices, storing and moving devices selected may var~r depending on
many factors, the
illustrated cores may be varied to accommodate tt~e equipment available or
selec~ed.
Examples of variations in the core design to accommodate lifting and moving
devices are
illustrated in FIGS. 6-8A, 14 and 30. As shown i.n FIG. 30, for example, each
core print 386 on the
32
CA 02358077 2001-09-20
bolster center core 300 may have a pair of recesses 500 defining a shelf 502
for receiving the end of
a lifting device. As shown in FIGS. 6-8A and 14, the sideframe center core 82
may have an central
opening 504 with an interior shelf 506 as shown in FIG. 8A; thus, a group of
lifting arms 508 can be
used, each rotating about its central longitudinal axis S 10, with a
perpendicular segment 512 that
rotates to fit under the interior shelf 506 so that the core may be lifted.
'The lifting devices may then
be rotated so that the perpendicular segments are no longer under the shelf
when the core is
deposited in its proper position on the drag mold, for example. Preferably,
the lifting devices
contact the cores in areas such as the prints to avoid harming the cores.
It should be understood that standard foundry practices should be used along
with the
disclosures of the present invention, such as providing chill plates where
necessary for the best
quality casting. It should also be understood that the illustrated cores do
not necessarily show
recesses to form the chill plates, and the absence of chill plates or recesses
in a drawing should not
be considered as a teaching that none are necessary or desirable. Similarly,
where slits are shown in
cores that may correspond with chill plates generally, it should be understood
that the positions of
the chill plates may be other than as shown, as the drawings are merely
illustrative of such features.
Standard foundry practices may be used in washing and drying the cores. In
accordance
with standard foundry practices, various surfaces such as the longitudinal and
lateral limit surfaces
of the sideframe end, center and bottom center cores and bolster center and
end cares, and. various
walls and ribs may have slight drafts incorporated into the design to
facilitate rerrroval of the cores
2~ from the core boxes.
Fox handling the finished cores in, for example, transferring the core frorra
the core-making
site to the site where the cores are placed in the mold, it may be desirable
to provide pallets that are
capable of supporting the combined cores.
While only specific embodiments of the invention have been described and
shown, it is
apparent that various alternatives and modifications can be made thereto. For
example, although the
cores have been shown shaped to produce particular railway truck parts, it
should be understood that
changes in shapes rnay be made for other types of railway trucks, and the
invention is not limited to
the illustrated style of railway truck. In addition, although the invention
has been described with
respect to particular core structures for producing railcar truck parts, the
principles of the invention
33
CA 02358077 2001-09-20
may be applied to the production of other cast metal structures. It is,
therefore, the intention in the
appended claims to cover all such modifications and alternatives as may fall
within the true scope of
the invention.
34
