Note: Descriptions are shown in the official language in which they were submitted.
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RADIAL TRUCK
Technical Field
The technical field of this invention is railway
car rolling stock. It particularly relates to railway car
trucks which are self-steering radially.
Background of the Invention
The benefits of self-steering are numerous, the
principal ones being greatly improved curving character-
istics resulting in substantial reduction of rail and wheel
wear; complete elimination of lateral instability known as
"hunting" throughout the operating speed range which results
in reduced truck and car body component damage and wear;
elimination of a major cause of derailments; reduced lading
damage; a substantial savings in fuel due to the reduced
tractive effort required to haul a vehicle which is track-
ing correctly, reduced gage widening of track., etc.
A radial truck construction utilizing a steering
arm design is shown in my copending Canadiallapplication Serial
Number 326,243, filed April 24, 1979.
The steering arm of the above mentioned appli-
cation, in one embodiment, is designed to retrofit to a
truck utilizing a so-called "rod-through" truck brake rig-
ging which means that the brake rigging connection rod
passes through one of two off-center holes in the truck
bolster.
The other hole is utilized to pass the steering
arm center connecting post to complete a flexible con-
nection with the mating steering arm at the longitudinal
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centerline of the truck.
The "rod-through" brake rigging requires that the
anchor of the system be applied to the truck bolster and as
this is located off-center, the resulting force couple produced
effects a rotating force on the truck during brake applications
and biases the truck in one direction at an angle to the
direction of travel.
This rotative action tends to cause the wheel
flanges at diagonal locations of the trucks to wear at a faster
rate than the opposite diagonally located wheels.
It also biases the truck in one direction to cause
parallelogramming or lozenging to occur consistently in that
direction to further increase wheel flange wear at the diagonal
location.
Since the wheels are permanently applied to the
axles, the badly worn wheel of a pair governs the remachining
period to reestablish the correct profile and the result is
that much more metal must be removed from the unworn wheel to
bring the pair into compliance than would otherwise be
necessary. This represents an uneconomic loss of usable wheel
tread metal.
The radial truck steering ability restrains the
truck from parallelogramming or lozenging and resists the
wholesale unsquaring of the truck by the brake forces, but
it cannot completely eliminate this problem.
Also, the current radial truck arrangement steering
arm connecting post is off-center per my copending application
Canadian Serial No. 326,243, filed April 24, 1979, to pass
through the existing truck bolster hole, this requires that
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the mating arms be left- and right- handed which increase the production
cost in addition to adding complication to the design and the assembly
procedures, etc.
To combat the above enumerated problems, the present invention
has a primary objective of providing a truck bolster and radial steering
arm design which will accommodate a symmertical arrangement together
with a rod-under truck brake rigging.
The present invention resides in a railway car truck comprising
at least a pair of longitudinally spaced wheelsets composed of axles with
spaced apart wheels mounted thereon, a pair of sidefra~es mounted on the
wheelsets, a truck bolster having a center section mounted on the pair of
sideframes, a pair of steering arm members, one for each axle, having means
for rotative mounting of the axles, each steering arm member extending from
its axle to a point substantially midway between the axles where they are
pivotally connected. A longitudinal center sill is disposed above the truck
bolster, and a body bolster intersects the center sill, the center sill at
the junction of the body bolster, having a bottom open pocket. In the
present invention the truck bolster has a centrally located relatively flat
upper surface with a centered upwardly projecting post for pivoting the truck
when negotiating curved track. The center sill contains an apertured center
filler in the open pocket for receiving the post. A resilient bearing plate
is disposed between the flat upper bearing surface of the truck bolster and
the lcwer bearing surface formed at the body bolster by the center sill
center filler assembly. The bolster center section is provided with a
lateral opening to provide operating clearance for the pivotal connection
of the steering arm members.
An object is to provide a truck bolster with a
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central aperture to accommodate steering arm connector posts
while maintaining the required section strength at the bolster
centerline.
A further object is to provide a bolster with an
improved center bearing which will also add depth to the bolster
centerline section.
A specific embodiment of the invention provides a
resilient center bearing sandwich liner to reduce the load
concentration caused by car body rocking and render the new
center bearing an acceptable improvement over the conventional
center plate.
Yet another object is to achieve maximum simplicity
in the design and application of the steering arms by making
them symmetrical about the longitudinal centerline of the
truck. An additional object is to provide a central pivot for
the truck, which will present a large bearing area and can be
equipped with a highly wear resistent sleeve, as an acceptable
improvement over the conventional center plate and loose pin,
and, a component of the means of increasing the bolster depth
for strength purposes in view of the required aperture.
Brief Description of the Drawing
Other objects and advantages of the invention will
be apparent from the detailed description and the accompanying
drawings, in which:
Figure 1 is a plan view of a railroad freight truck
in which has been incorporated a steering assembly;
Figure 2 is a side elevation of the truck of Figure
1 partially in section;
Figure 3 is a fragmentary end view partially in
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section of the truck of Figure l;
Figure 4 is an elevation view, partly in cross-
section, of the resilient center bearing plate; and
Figure 5 is an isometric exploded view of the body
bolster center pivot bearing assembly.
Detailed Description of the Preferred Embodiment
In accordance with the present invention, there is
provided a railway car truck comprising at least a pair of
longitudinally spaced wheelsets composed of axles with spaced
apart wheels mounted thereon. A pair of sideframes
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are mounted on the wheelsets. A truck is bolster mounted on
the pair of sideframes. A pair of steering arm members, one
or each axle, rotatively mounted on said axles. Each
steering arm member extends from its axle to a point sub-
stantially midway between the axles where they are pivotally
connected. A longitudinal center sill is disposed above the
truck bolster. A body bolster intersects the center sill.
The center sill, at the junction of the body bolster, has a
bottom open pocket. The truck bolster contains a centrally
located, relatively flat upper surface with a centered up-
wardly projecting post for pivoting the truck when negoti-
ating curved track. The center sill contains an apertured
flush center filler in the open pocket for receiving the
post. A resilient bearing plate is disposed between the
flat upper surface of the truck bolster and the body
bolster - center sill.
Referring now in detail to the drawings in which
like reference characters represent like parts, the im-
proved radial truck of the present invention retains the
essentials ~f the construction of the aforementioned
copend-ng application, while makin~ otherwise
unrelated structural changes to the conventional truck/car-
body interface to accommodate the related improvements.
The improved radial truck 1 compri6es conventional
side frames 2, improved bolster 3, wheelsets 4, improved
steering arms 5, and brake rigging (only bralce beam 35
shown) as the principal components.
The side frames 2 receive and support the bolster
3 in a conventional manner, the frames and the bolster ends
6 being generally of standard construction.
The center section 7 of the bolster 3 is provided
with an opening 8 located on the lateral centerline and of
sufficient lateral and vertical dimension to provide
operating clearance for the connector posts 32 of the steer-
ing arms 5. The top wall 9 of the bolster diverges in an
upward slope at the center to merge with a flat circular
plate area 10 which constitutes the center bearing area 11.
At the center of the circular bearing area 11 is an upwardly
projecting post 12 which is the pivot about which the truck
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1 rotates to negotiate curved track. Post 12 is shown as
cast or machined, but it could be provided with a hard
wearing sleeve about its periphery 13.
To rotatably receive post 12, the car body centèr
sill 14 and body bolster 15, junction 16 is provided with a
center filler 17 which enters the open bottom pocket 18
formed by the application of spaced shear plates 28 at
junction 16 from below and is secured such as by welding in
place. The bolster sole plate 19 (this could also be a flat
.. 10 wear plate or a combination), is applied in the usual manner
but with a hole 27 to correspond to the aperture 34 and
permit entry of the post 12 when the truck 1 and car body
are assembled.
The flat lower surface 21 of the sole plate 19 is
arranged to interface with the flat circular bearing area
surface 11 of the bolster center section ? through the
cushioning medium of a resilient sandwich bearing plate 23
made up of a layer of elastomer 24, bonded between circular
hardened steel plates 25. The center 26 of the sandwich
bearing plate 23 is removed to form a hole proportioned for
the passage of post 13. The purpose of the resilient sand-
wich bearing plate 23 is to relieve the edges of the bearing
surfaces 21 and 11 from experiencing a high concentration of
load during angular excursions of the car body (not shown)
about the horizontal or lateral axes.
The steering arms 5 comprise two side arms 29, a
central beam 30, corner connections 31 and center connector
post 32, all of which are preferably made integral whether
of cast or fabricated construction. The construction is
generally similar to my co-pending patent application ~dian
Serial Number 326,2~3 with the exception that the central
beam 30 is lower in relationship to the side arms 29 and the
connector posts 32 are centrally located. The flexible
center connection 33 between the mated steering arms can be
any one or a combination of the various embodiments covered
in my above-mentioned co-pending patent application.
It should be understood that the described and
disclosed embodiment is merely exemplary of the invention
and that all modifications are intended that do no~ depart
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from the spirit of the invention and the appended claims.
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