Note: Descriptions are shown in the official language in which they were submitted.
I
SUMMARY OF THE INVENTION
The present invention relates to frame less self-
steering radial wheeled support vehicles, such as car trucks
or bogies, which are used to support a railroad car body.
A primary purpose of the invention is a self-
steering radial truck or bogey or wheeled vehicle of the type
described which permits limited yaw and lateral movement of
the wheel sets relative to each other.
Another purpose is to provide a large wright reduce
lion in a self-steering radial truck or bogey or wheeled
vehicle, when compared with trucks having conventional side
frames and bolsters.
Another purpose is to provide a railroad car truck
having good hunting stability for the wheel sets and car body
at vehicle speeds substantially beyond normal railroad
operating speeds.
Another purpose is a truck of the type described in
which the conventional side frames and bolster have been
eliminated and in which the car body is independently sup-
ported at each end of each wiliest.
Another purpose is a frame less self-steering radial
wheeled vehicle which includes resilient pads or equivalent
yielding resistance to relative movement which provides for
both lateral and yaw movement of the wheel sets relative to
the car body.
Another purpose is a wheeled vehicle of the type
described in which there are separate and independent series
resistances to relative lateral movement of the car body and
wheel sets.
Another purpose is a wheeled railway support
vehicle of the type described in which the car body is in
pendently supported at opposite ends of each wiliest, which
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support includes springs and wedge-type dampers, with oppo-
site ends of the wheel-sets being connected together and
constrained for relative yaw movement.
Another purpose is a frame less radial railway
support vehicle of the type described which permits
restrained lateral and yaw movement of the wiliest and
prevents relative longitudinal movement of the wheel sets.
Other purposes will appear in the ensuing
specification, drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
_
The invention is illustrated diagrammatically in
the following drawings wherein:
Figure 1 is a partial top plan view of a railway
vehicle of the type described,
Figure 2 is a side view of the railway vehicle
disclosed herein,
Figure 3 is a partial section taken along plane 3-3-
of Figure 2, and
Figure 4 is a diagram illustrating lateral deflect
lion vs. lateral shear force per wiliest for the railway vehicle disclosed herein.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The term "radial truck" has been used in the
railroad industry to designate a railway support vehicle or
truck or bogey which is essentially self-steering or which
con follow the radius of curvature of most curves found in
conventional railway usage. Heretofore, radial trucks have
used as a foundation the conventional three-piece concept of
two side frames and a bolster to form the frame for the truck
and to form a means whereby the car body is supported on the
truck.
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The present invention is particularly concerned
with radial truck in which the bolster and side frames have
keen eliminated, with very substantial savings in weight for
each railroad car. Specifically by eliminating the bolster
and side frames conventionally found in most railroad bogies,
there is a reduction in weight of approximately 5,000 lobs per
car. By eliminating the bolster and side frames, changes in
the support structure of the car body can be made which will
eliminate an additional 3,000 lobs of weight per car.
Accordingly, the frame less radial truck of the present invent
lion can provide a railroad car weighing in the area of 8,000
lobs. less than previous cars suitable for the same traffic.
This reduction in weight not only permits the car to carry a
greater load/ but also provides substantial fuel economies in
running unloaded cars
Elimination of the side frames and bolster,
however, presents many design problems since these elements
provide the means whereby the car body is supported on the
truck and they provide the basic frame whereby the truck is
selr-steering and through which constraints are placed on the
lateral and yaw movements of the wheel sets during self-
steering. Specifically, the present invention provides a
frame less radial self-steering support vehicle for a railroad
car environment in which the bolster and side frames have
been eliminated; in which the car body is independently
supported on each end of each wiliest; in which there are
resilient shear pads constraining both lateral and yaw move-
mints of the wheel sets relative to the car body; and in which
there it a connecting linkage between adjacent ends of each
wiliest, which linkage constrains the wheel sets to yaw in
opposite sense while permitting lateral movement of one
wiliest relative to the other and which further contains the
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the wheel sets from net longitudinal movement with respect to
each other.
A pair of spaced conventional wheel sets are India
acted at 10 and 12~ there being a wheel 14 attached on the
illustrated end of each wiliest. It is understood that the
top plan view of Figure 1 only shows a portion of the truck
and that the wheel sets will continue with identical struck
twirl not shown, on the opposite side of each truck or
vehicle. Wheels 14 may be of conventional keenest or may
have a special profile. It is preferred to use a profile
similar to that of a worn wheel which has a high effective
keenest with approximately a 0.5 inch flange clearance with
the rail and a high flange contact angle. Such a keenest
has a profile quite similar to that of a naturally worn
wheel.
Each of the wheel sets 10 and 12 will have a roller
bearing 16 at each end of the wiliest and each roller
bearing 16 will support a roller bearing adapter 18. Mounted
upon each roller bearing adapter 18 is a plurality of nest-
lint shear pads indicated generally at 20. There may be a
single shear pad, although it is preferred that there be
multiple or a plurality of shear pads, as illustrated. The
pads will be of similar size and shape and will be separated
by metal plates, as is conventional. Shear pads 20 should be
formed of a material which will provide a predetermined
amount of damping within the material of the pads of not less
than ten percent of critical damping in order to provide
adequate car body stability under loaded car conditions.
The shear pads support a pedestal indicated
generally at 24. Pedestal 24 has a bottom portion 26, up-
standing side walls 28 and a top portion 30 which is seated
upon shear pad 20. In effect walls 28 and 30 form a small
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housing which not only is supported upon the shear pad, but
restricts the amount of lateral and yaw movement between the
wiliest and the pedestal. As particularly illustrated in
Figure 2, there are gaps between adapter 18 and housing walls
28. These gaps permit yaw movement of the wheel set in an
amount equal to the longitudinal clearance which, in the pro-
furred embodiment, may be on the order of one and one-quarter
inch. Adapter 18 has upstanding inboard and outboard ears 27
and 29 respectively which cooperate with top wall portion 30
to permit a similar amount of lateral movement of the wheel-
set relative to the pedestal. This amount of movement may be
on the order of an inch in each lateral direction. Thus,
when considering the relationship between the wiliest, its
roller bearing adapters, the supporting resilient shear pads
20 and the pedestals 24 which are mounted upon the wiliest
by the shear pads, the wheel sets have a permitted yaw and
lateral displacement relative to the pedestals or the support
structure.
Each pedestal includes, as a part of bottom member
26, an outside platform 32 at one side of the bottom member
and an inside platform 34 at the opposite side. Each of the
platforms 32 and 34 mount springs 36 which are similar to
conventional load bearing or load carrying springs normally
found between the side frame and bolster of a car truck.
Springs 36 support the weight of the car body on the pedestal
and thus the wheel sets. In addition to springs 36, there are
smaller damping springs 38 supported on the platforms, which
damping springs 38 each support a friction wedge or damping
member 40. Wedges 40 bear against wear plates 42 mounted on
the outside of walls 28, much in the manner of a convention-
at three-piece truck. The wedges or friction members fit
within pockets 44 formed in a wiliest frame member 46 which
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extends over the top of the roller bearing adapter, shear
pads and pedestal top member 30 and had downwardly facing
seat areas 48 at opposite sides thereof which form the upper
seat for springs 36. Thus, wiliest frame members 46 are
supported on springs I and in turn will support the car
body, as described. There is only a small, about one-eighth
inch, lateral clearance between frame member 46 and side
walls 28 and the side flanges of the frame member are in
contact with plate 42.
Formed at opposite sides of each wiliest frame
member 46 is an upper platform 50 which has a generally horn-
zontal portion and an upwardly slanted portion. Positioned
on each platform 50 is a resilient shear pad construction 52,
which again may be a single shear pad or a plurality of shear
pads, although the latter is preferred. Shear pad construe-
lions 52 each include shear pads with a horizontal portion 54
and an upwardly directed or slanted portion 56. The shear
pads fit within the contour defined by platforms 50 and
support on the upper ends thereof a friction member or wedge
58, specifically illustrated in Figures 2 and 3.
Wedge members 58, which may be formed of the same
metallurgical composition as friction wedges 40, seat upon
the shear pads as described and have an upper wedge-shaped
nose 60 which extends within a similar wedge-shaped pocket 62
of a wedge cover 63 which is attached to car body 64. Wedges
58, there being two such wedges at each end of each wiliest,
independently support the car body upon the wheel sets. The
car body wedge covers 63 maintain the wedges in position
within the pockets and resting upon the shear pad construe-
lion. Each of the wedge members I has a slope on the opposite surface from that in contact with the upward slanted
portion 56 of the shear pad. The sloping surface, indicated
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at 57, has approximately the same direction or is generally
parallel to the slanted surface of shear pad portion 56.
Sloping or slanted surfaces 57 further have a crown or slight
radius in the slanted direction as will be explained in
detail hereinafter.
Adjacent ends of wheel sets 10 and 12 are pivotal
connected together. Pedestals 24, specifically the inboard
platforms thereof, indicated at 34, each pivotal support a
bearing housing 70 which includes a bearing member 72 having
an internal pillow block 74. The pivotal connection, which
may be a pin and slot configuration 71, preferably allows for
lateral deflection of the pedestal of one wheel set with
respect to the other by permitting rotational and longitude-
net movement. Pillow blocks 74, at opposite sides of the
bogey, support a torque rod or tube 76 extending from one
side of the vehicle to the other. Positioned on the outboard
ends ox torque rod 76 and at each end thereof is a Levis 78,
particularly illustrated in Figure 2. One side of Levis 7B
is pivotal attached to a rod 80, with the opposite end of
the rod being pivotal attached to a roller bearing adapter
18. In like manner, a rod 82 is pivotal attached to the
other side of Levis 78 and is pivotal attached to the
roller bearing adapter of the other wiliest. Opposite ends
of rods 80 and 82 include resilient bushings aye and aye as a
part of each pivotal connection to provide a degree of yaw
freedom with respect to the roller bearing adapter and Levis
for lateral deflection of the wheel sets.
It is important to note that rods 80 and 82 are
each pivotal attached to the upper portion or top of the
roller bearing adapters, but are attached to the bottom and
top of Levis 78. At the opposite end of the torque tube the
connections to the Levis will be in the reverse sense. That
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is, the connection from wiliest 12 will be to the top of the
Levis and the connection from wiliest 10 will be to the
bottom of the Levis.
Although not shown, damping members, conventionally
a small piston and cylinder with attached rods, may be con-
netted between the pivotal connections of the Levis and the
pivotal connections with the roller bearing adapters to damp
any oscillatory movement brought about during yaw of the
wheel sets. The damping members would be useful in preventing
truck hunting.
The truck described herein permits constrained
relative yaw movement between the wheel sets as would be
brought about when the car enters curved track. In like
manner, during the period when a car is negotiating a curve,
there may be a required lateral deflection of each wiliest
relative to the car body to permit the wheels to stay in
position upon the rails. When the railroad vehicle enters a
curved track wheel sets 10 and 12 will yaw to assume a radial
configuration relative to the radius of curvature of the
I track. Shear pads 20, which are positioned between the
roller bearing adapters and the support pedestals, will
permit the degree of yaw necessary to negotiate approximately
an eight-degree railroad track curve. As indicated above,
there is an-inch-and-a-quarter of space on each side of
adapter 18 to accordingly permit yaw movement of that degree
between the roller wearing adapter and the supporting
pedestal The wheel sets are connected together and rods 80
and 82 will not interfere with the natural yaw movement of
wheel sets having a high effective keenest. When wheel sets
of lower keenest are used, the rods will constrain yaw
movement of the wheel sets As wheel sets 10 and 12 move
together at the end shown in Figure 1, rods 80 and 82 will
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cause torque tube 76 to rotate in a clockwise direction. The
opposite ends of the wheel sets would move apart. And since
the connections of the corresponding rods are opposite to
those illustrated in Figure 2, this would impart the same
clockwise turning movement to torque tube 76. Thus, the
torque tube has no torsional movement or stress applied to it
during conventional yaw movement. Shear pads 20 will permit
a degree of yaw movement consistent with negotiating an
approximate eight-degree curve. Once the roller bearing
adapter has contacted sides 28 of the pedestal, brought about
by yaw movement as described, resistance to further yaw move-
mint will be taken up by the diagonal or upwardly slanted
portions of shear pads 52 and wedges 58 which support the car
body on the ends of the wheel sets.
In addition to yaw, there are lateral forces
applied to the wheel sets during curving which require lateral
deflection of the wheel sets relative to the car body. Shear
pads 20 again will provide an amount of lateral movement
consistent with that required to negotiate an approximate
eight-degree curve If the curve is more severe, the roller
bearing adapter ears will contact top member 30 after a pro-
determined lateral movement. Further efforts at lateral
movement by the wheel sets will be accommodated by shear pads
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Referring to Figure or a curve relating lateral
shear deflection and the lateral shear force applied per
journal or at one end of a wiliest, the American Association
of Railroads (AJAR) requires thaw a car negotiate a 150 ft.
curve before it can have AJAR certification. The AJAR also
requires traversing a ten-degree curve with 200,000 lobs. of
squeeze applied to the car. This is a substantially more
severe test than the eight-degree curvature for which the
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truck is designed and which will accommodate most railroad
use. to successfully run through a 150 ft. curve and main-
lain the wheels on the rails, it is necessary that the wheel-
sets, with the described permitted yaw, have a lateral shear
deflection of 4-3/4 in. with respect to the car body. In a
loaded car, the first one inch of such deflection will be
accommodated by shear pads 20, as described. The remaining
3-3/4 in. will be accepted by shear pads 52. The two shear
pads function in series in that the resistance of a pair of
pads 52 does not become effective until the wiliest has
moved the permitted deflection of pad 20. The two shear pad
constructions, in combination, will permit a lateral wheel
set shear deflection of 4-3/4 in. which is required to
negotiate the prescribed AJAR curve. This is represented by
curve 92 of Figure 4.
A light or unloaded car presents different
problems. The first one inch of deflection will again be
accommodated by shear pads 20. The next one-fourth inch
deflection will be accommodated by shear pads 52. However,
further lateral deflection between the wiliest and the car
body will be accommodated by movement of the car body wedge
pocket relative to the wedge specifically illustrated in
Figure 3. The lateral forces applied by the rails to the
wheel sets will cause the wedges 58 to move within pockets 62.
As illustrated in figure 4, at a predetermined lateral shear
force on the unloaded car wiliest the wiliest will deflect
the required remaining distance by the described wedge move-
mint. This is illustrated by curve 90.
Wedges 58 and associated pockets 62, the car body
shear pads 52 and the wheel sets shear pads 20, individually
and in combination, effectively provide for the required
4-3/4 in. deflection necessary to negotiate the required AJAR
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curve, under all car loading conditions. The specific wedge
configuration is also advantageous in that it assists in
restoring the car body and wiliest to the original non-
deflected position.
The combination of the slope of shear pad portion
56 and the shape of rear wall wedge surface 57 and the
slanted configuration of the wedge pocket prevents the wedge
from sliding in the car body wedge pocket under loaded car
conditions For example, such might occur if surface 62 of
the wedge pocket becomes contaminated with oil or water, a
not uncommon condition in a railroad environment. At loaded
car conditions, shear pad 52 will have a reload deflection
approximately one-half inch, which will cause a predetermined
normal force between the slope shear pad and the facing wedge
surface. This force will prevent vertical movement between
the wedge and the pocket, which in turn will prevent lateral
movement between the wedge and pocket at loaded car
conditions. At light or unloaded car conditions the sloped
or slanted surfaces 62 of the two wedge pockets are spaced in
the longitudinal direction such that there is no reload
between the wedge and the pocket.
In order to successfully negotiate the required AJAR
curve, if cross anchors or cross rods were used to connect
opposite ends of the wheel sets, as is conventional id radial
trucks, it would be necessary to have in the area of six
inches of yaw movement at each wiliest. It is impossible to
accommodate yaw movement of that degree. Accordingly, the
required movement of the wiliest to negotiate the curve is
largely taken up by the lateral movement described above.
There is still yaw movement; however, it is on the order ox
the one-and-one-quarter inch of permitted movement described.
Because the wheel sets are moving in a lateral direction, the
72~
torque tube must be mounted in a pillow block which will
permit the torque tube to pivot relative to its mounting. In
like manner, housing 70 for opposite ends of the torque tube
must be able to pivotal move relative to the wiliest
supports to permit the required lateral and yaw movements
necessary to move the truck around curves
Both lateral and yaw movements are required in
negotiating curves and the support system for the vehicle
permits such movement. The wheel sets are constrained against
relatively longitudinal movement, either toward or away from
each other, both by the housings 70 and by the torque tube
If the wheel sets are urged longitudinally apart, this move-
mint will be resisted by the torque tube because of the
manner in which the rods 80 and 82 are connected to opposite
ends of the torque tube. Similarly, loads applied to the
support pedestals 24 which might tend to move one of the
shear pads out of engagement with the car body support will
be resisted by the torque tube supports 70.
When railroad vehicles of the type described are
used on unit trains which function with automatic dumpers, a
squeezing movement is applied to the truck wheel sets during
the dumping operation. Rods 80 and 82 connected, as desk
cried, to torque rod 76, not only will accommodate yaw and
lateral movements, as described, but are sufficient to resist
this substantial squeezing movement. When the truck wheel-
sets are being held in an automatic dumper locking device,
large longitudinal forces are applied to the car body by the
forces applied to the train. These forces are transmitted to
the locking device through the truck system. In this Dyson
such forces would tend to rotate the pedestal assemblies
about roller bearing 16~ Such loads applied to the support
pedestals which might otherwise tend to move a shear pad out
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of engagement with the car body support will be resisted by
torque tube supports 70.
In a conventional rigid three-piece car truck,
hunting is manifested by a pivoting of the entire rigid truck
about the center pivot point of connection to the freight car
body. In a self-steering truck, without connections between
wheel sets, hunting is brought about by oscillation of the
individual wheel sets. In a radial frame less car truck system
where there is a low yaw constraint between the wheel sets and
the frame for curving, hunting stability is acquired by the
interconnection of the wheel sets such that they are forced to
yaw in an opposite sense with respect to each other. This
interconnection between wheel sets must have a predetermined
minimum stiffness and, as shown herein, the predetermined
minimum stiffness required is the connection between the
roller bearing adapter and Levis 78. The stiffness may be
provided by the rod, such as rod 80 or 82, which forms the
connection, or as is preferred, by the bushing mounted upon
the Levis which is a part of the connection. the stiffness
of the connection or the spring rate of the material of the
bushing must be a predetermined minimum and when the stiff-
news is below such predetermined minimum, the speed at which
hunting occurs drops off dramatically. Similarly, the stiff-
news cannot be too great or again the speed at which hunting
occurs will drop off dramatically. It is preferred that the
stiffness of the connection or the resiliency of the connect
lion be provided by the bushing forming a part of the connect
lion rather than the rod, so that the stiffness of the rod
alone, after the resiliency permitted by the bushing has
bottomed out, can be used in car braking. For example the
combined effective stiffness provided by the resilient
bushings at each end of the rod should be not less than
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40,000 lobs. per inch to provide good truck hunting stability
at unloaded car conditions.
Whereas the preferred form of the invention has
been shown and described herein, it should be realized that
there may be many modifications, substitutions and
alterations thereto.
