Note: Descriptions are shown in the official language in which they were submitted.
I
MULTIPLE AXLE SELF-STEERIMG
POWERED LOCOMOTIVE TUCK
CROSS References
Jo :
The present application relates to improvements
in my prior Canadian application Serial No. 336,776, filed
October 1, 1~79, and also in my prior Canadian Patent No.
1,065,190, issued October 30, 1979.
BACKGROUND AND STATEMENT OF OBJECTS:
Certain forms of multiple axle self-steering rail-
way trucks are known, particularly for use in railway cars.
Several forms of such self-steering car trucks are disclosed
in the above identified prior applications. The truck arrange-
mints disclosed in my prior applications comprise a pair
of axle wheel sets mounted in a truck frame structure with
freedom for relative yaw motion of the axles and each axle
wiliest having a steering arm, with the two steering arms
interconnected in a region between the axles to provide
for interchange of steering forces between the steering
arms and thus provide for interchange of steering forces
between the wheel sets in the yawing sense.
In said prior applications, arrangements are shown
in which the devices which interconnect the steering arms
are arranged to interchange the steering forces between
the steering arms and the wheel sets independently of yaw-
inducing connection with the main frame or other parts of
I I
the truck structure. The foregoing provides self-steeing
action of such effectiveness and accuracy as to virtually
eliminate the angle of attract between the wheel flanges
and the rails on which the truck is traveling. Smoother
tracking is thereby provided under all conditions. This
greatly reduces noise and wear between the wheels and rails
in curves, improves high speed stability and ride quality
with reduced maintenance of the track, trucks and car structure.
One of the principal objectives of the present
invention is to provide a self-steering action of the char-
cater just referred to in a powered truck of a locomotive
and to adapt this self-steering character to the powered
truck of a locomotive in such a manner as to provide for
effective delivery of the driving force from the driven
wheel sets to the main frame of the truck and thus to the
locomotive itself, notwithstanding the freedom provided
for the self-steering activity of the wheel sets in the yaw-
in sense.
Another objective of the present invention is
to provide a novel arrangement of brakes and brake parts
for the driven wheels the brake equipment being mounted
at least in part on the main frame of the truck, but being
arranged to accommodate yawing motions of the wheel sets
even at times during the application of the brakes.
I
In one preferred embodiment according to the pros-
en invention, the powered truck incorporates two wheel-
sets, each provided with a steering arm and each of which
wheel sets is independently motorized, i.e., the axle of
each wiliest carries its own driving motor, and means are
provided for transmitting motor torque forces directly from
the motor to the truck frame In another embodiment, means
are provided for transmitting torque forces through the
steering arms to the truck frame
It is a further object of the present invention
to provide a pivotal interconnection structure between the
steering arms associated with each axle wiliest, the in-
terconnection structure being arranged to transmit traction
forces between the steering arms, provision also being made
to transmit traction forces from the steering arms to the
truck frame in various different relatively angled post-
lions of the steering arms.
In summary of the foregoing and of other features
of the present invention, it will be seen that it is a gent
oral objective of this invention to improve the tracking behavior of railway locomotive trucks, particularly a two-
axle or Tolstoy truck. Such improvement in the track-
in behavior increases the adhesion available for traction
and further reduces the flange forces and thus the wear
on both the wheels and the track not only in curves but
also on straight track.
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Prior art or conventional powered trucks exert
lateral forces on the track which are generally much greater
than those required to guide the vehicle along the track
centerline. In curves, most of the extra lateral force
is the result of tracking errors for the leading axle which,
in conventional trucks, is restrained to remain parallel
with the trailing axle in consequence of which, the lead-
in axle will have a substantial angle of attack with no--
spent to the rail in the yawing sense This angle of attack
not only create unnecessary lateral force, but also causes
a substantial loss of potentially available longitudinal
adhesion for pulling the train. In curves, additional dye
namic forces result from the fact that the leading axle,
having a large angle of attack, will tend to follow, in
detail, all the irregularities present in the alignment
of the rails.
The foregoing disadvantages are virtually elm-
inated by the provision of the self-steering arrangement
for a powered truck a provided in accordance with the pros-
en invention.
In prior art powered trucks operating on straighttrackl there are unnecessary lateral forces arising from
unneeded steering action, which lateral forces can be of
sufficient magnitude to cause wheel flange-to-rail impact,
and such impacts have commonly occurred at a frequency
approximating 2 to 5 impacts per second These undesirable
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motions have arisen with conventional powered trucks in
which the axles, while remaining generally parallel to each
other, can move individually with substantially no restraint
within the longitudinal and lateral clearances present in
the mounting of the ale bearing structures in the pedestal
jaws of the truck frame.
The selE-steering type of powered truck of the
present invention eliminates the unnecessary lateral motions
and forces above referred to.
The arrangement of the present invention is adapted
or use in powered trucks having axle-hung traction motors.
This type of powered truck is especially subject to tracking
errors induced by the combination of pedestal jaw clearances
and the lateral forces acting at the motor nose The pod-
vestal clearances allow lateral motion of the truck frame
relative to the axle. This motion causes an undesirable
yaw motion of the motor/axle assembly through the lateral
force at the motor nose which is located longitudinally
a substantial distance from the axle.
The arrangement of the present invention is effect
live in providing self-steering even with axle-hung traction
motors. The reason for this is that the motor/axle assembly
is firmly guided in yaw by the steering arms without the lost
motion of the pedestal clearances. Further, in one embody-
mint, the motor nose is supported directly by the steering
arm, completely eliminating all influence of lateral motor
nose forces.
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Although it is theoretically possible to support
the traction motors from the vehicle body or truck frame
instead of from the axles, and provide a flexible coupling
in the drive train between the motor and the axles, this
approach introduces the mechanical complexity of the flex-
bye coupling and this is a substantial structural drawback.
On the other hand, the arrangement of the present invention
provides the opportunity to support the traction motors
from the steering arms. This greatly reduces the motions
imposed on the flexible coupling, making this a much more
attractive option for removing the traction motor from the
unsprung axle weight category.
In summary, it is pointed out that the arrange-
mints of the present invention effectively provide for steer-
in motions of the powered axles which minimize the wheel/rail
angle of attack in curves and also provide a stabilizing
restraint of undesirable axle activity on straight track.
In accordance with the present invention, the
vertical load-carrying connection between the truck framing
and the axles has flexibility in the longitudinal direction
to allow for yaw motion of the axles relative to the frame
in. The interconnection between the steering arms is
arranged in a region midway between the two axles of a two-
axle powered truck; and according to the present invention,
this interconnection provides for interchange of lateral,
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vertical and longitudinal forces between the two axles,
without significantly restraining the relative yaw motion
as required in order to permit the axles to assume radial
positions with respect to curved track. The interconnect
lion also serves to transmit yaw forces from one wiliest
to the other. At the same time, in accordance with the
present invention, the interconnection between the steering
arms provides a relatively stiff restraint of differential
steering motion such as would be required for the two axles
to assume positions corresponding to the sides of a non-
rectangular parallelogram; and this restraint is of import
lance in order to provide high-speed stability on straight
track.
The foregoing factors are of special importance
in a powered truck of a locomotive, because preventing the
wheel/rail angle of attack associated with tracking errors
causes a consequent increase in the overall adhesion and
thus in the utilization of the available power of the drive
in motors.
It is also a major objective of the present invent
lion to provide for the retrofitting of certain existing
powered trucks by adding steering arms and other related
equipment to provide the operating advantages above referred
to
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With the foregoing objectives in mind the pros-
en invention provides a powered railway truck comprising
a load-carrying Frame a pair of axle wheel sets each having
journal bearings mounted to support the truck frame and
having freedom for yaw motion of the wiliest with respect
to the truck frame, at least one wiliest also having a
drive motor mounted on its axle and movable in yaw with
the wiliest, a steering arm associated with each wiliest,
the wiliest with its motor and steering arm being jointly
movable in the yaw sense, pivot means interconnecting the
steering arms in the mid-region between the pair of wheel--
sets and including means enforcing substantially equal and
opposite pivotal yawing motion of the wheel sets of said
pair independently of the truck frame and thereby cause
both of the wheel sets to assume radial positions when travel-
lying on curved track/J, and for the wiliest having a drive
motor, means providing for the transmission of torque react
lion forces directly from the motor to the truck frame in-
dependently of the steering arm
In addition, the present invention also provides
a powered railway truck comprising a load-carrying frame,
a pair of axle wheel sets each having journal bearings mounted
to support the truck frame and having clearance providing
freedom for yaw motion ox the wiliest with respect to the
truck frame, resilient load-transmitting means between the
journal bearings and the frame, each wiliest also having
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a drive motor mounted on its axle and movable in yaw with
the wiliest a steering arm associated with each wiliest,
each wiliest with its motor and steering arm being jointly
movable in the yaw sense, pivot means interconnecting the
steering arms in the mid region between the pair of wheel-
sets and including means enforcing substantially equal and
opposite pivotal yawing motion of the wheel sets of said
pair independently of the truck frame and thereby cause
both of the wheel sets to assume radial positions when travel-
lying on curved track, and flexible connection means inter-
connecting the steering arm for each wiliest with the truck
frame in a region offset from said pivot means beyond the
axle of that wiliest and restraining relative lateral motion
of the truck frame and the steering arm in said offset region,
while permitting yaw motions of the steering arm.
In addition, the present invention also provides
a powered railway truck comprising load-carrying framing,
a pair of axle wheel sets each having journal bearings mounted
to support the truck framing and having clearance providing
freedom for yaw motion of the wiliest with respect to the
truck frame, resilient load-transmitting means between the
journal bearings and the framing, each wiliest also having
a drive motor mounted on its axle and movable in yaw with
the wiliest, a steering arm associated with each wheel-
set, each wiliest with its motor and steering arm being
jointly movable in the yaw sense pivot means interconnecting
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the steering arms in the mid-region between the pair of
wheel sets and including means enforcing substantially equal
and opposite pivotal yawing motion of the wheel sets of said
pair independently of the truck frame and thereby cause
both of the wheel sets to assume radial positions when travel-
lying on curved track, means for communicating the traction
forces from the steering arms to the truck framing, and
sprint means for delivering load from the framing to the
wheel sets, said spring means having sufficient yaw flex-
ability to substantially avoid communication of traction
forces from the wheel sets through the spring means to the
truck framing.
Still further, the present invention provides
a powered railway truck comprising a load-carrying frame,
a pair of axle wheel sets each having journal bearings mounted
to support the truck frame and having clearance providing
freedom for movement of each wiliest both laterally and
longitudinally of the truck and also for relative motion
to various different positions in yaw' each wiliest also
having a drive motor mounted on its axle and movable with
the axle, a steering arm associated with each wiliest,
the wiliest with its motor and steering arm being jointly
movable in the yaw sense pivot means interconnecting the
steering arms in the mid-region between the pair of wheel sets
and including means enforcing substantially equal and oppo-
site pivotal yawing motion of the wheel sets of said pair
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independently of the truck frame and thereby cause both
of the wheel sets to assume radial positions when travel-
lying on curved track, and, for each steering arm, means
associated with the steering arm and the truck frame in-
eluding an abutment pad positioned to communicate traction
forces between the steering arm and the truck frame, the
abutment pad being formed to provide surface-to-surface
contact, even in various different yaw positions of the
steering arm with respect to the truck frame.
In addition, the present invention also provides
a powered railway truck comprising a load-carrying frame,
a pair of axle wheel sets each having journal bearings mounted
to support the truck frame and having clearance providing
freedom for yaw motion of the wiliest with respect to the
truck frame, at least one wiliest also having a drive motor
mounted on its axle and movable in yaw with the wiliest,
a steering arm associated with each wiliest, the wiliest
with its motor and steering arm being jointly movable in
the yaw sense, pivot means interconnecting the steering
arms in the mid-region between the pair of wheel sets and
including means enforcing substantially equal and opposite
pivotal yawing motion of the wheel sets of said pair index
pendently of the truck frame and thereby cause both of the
wheel sets to assume radial positions when traveling on
curved track, and a sanding device for each motor driven
wheel, the sanding device being mounted on the steering
arm for the driven wheels.
-ED-
~34~
Still further, the present invention provides
a powered railway truck comprising a load-carrying frame,
a pair of axle wheel sets each having journal bearings mounted
to support the truck frame and having clearance providing
freedom for yaw motion of the wiliest with respect to the
truck frame, resilient load-tran~mitting means between the
journal bearings and the frame, each wiliest also having
a drive motor mounted on its axle and movable in yaw with
the wiliest, a steering arm associated with each wiliest,
each wiliest with its motor and steering arm being jointly
movable in the yaw sense, and pivot means interconnecting
the steering arms in the mid-region between the pair of
wheel sets and including means enforcing substantially equal
and opposite pivotal yawing motion of the wheel sets of said
pair independently of the truck frame and thereby cause
both of the wheel sets to assume radial positions when travel-
lying on curved track, said means comprising an element in-
termediate the steering arms, pivots connecting the steering
arms to said element independently of each other, and means
enforcing substantially equal and opposite pivotal motion
of the steering arms with respect to said element.
In addition, the present invention provides a
powered railway truck comprising side frame members and
transoms interconnected to provide a load-carrying truck
frame structure, a pair of axle wheel sets each having journal
bearings mounted to support the truck frame and having clear-
ante providing freedom for yaw motion of the wiliest with
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respect to the truck frame, resilient load-transmitting
means between the journal bearings and the frame, each wheel-
set also having a drive motor mounted on its axle and movable
in yaw with the wiliest, a steering arm associated with
each wiliest, the wiliest with its motor and steering
arm being jointly movable in the yaw sense, pivot means
interconnecting the steering arms in the mid-region between
the pair of wheelhouses and including means enforcing sub Stan-
tidally equal and opposite pivotal yawing motion of the wheel-
sets of said pair independently of the truck frame and there-
by cause both of the wheel sets to assume radial positions
when traveling on curved track, and means for transmitting
traction forces and motor torque forces from the steering
arms to the truck frame regardless of the relative yaw post-
lions of the wheel sets and steering Ayers
In addition, the present invention provides a
method for retrofitting a powered railroad truck with mock-
anise providing for wiliest steering, which method come
proses:
a) selecting an existing truck having load-
carrying side frame members with two pairs of
pedestal jaws each with pedestal liners, two wheel-
sets each comprising a pair of wheels fixed on
OF
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an axle having a driving motor and axle bearings
and bearing adapters received it the pairs of
pedestal jaws, the bearing adapters of each pair
having load-carrying spring connection with the
side frame members,
b) removing at least a part of the pedestal
liners to provide increased freedom for yaw move-
mint of one wiliest with respect to the other
wiliest,
I applying a steering arm to each wheel-
set, the steering arm being connected with the
wheel sets to provide for conjoint movement of
each wiliest with its steering arm in fixed rota-
lion in the yawing sense,
d) establishing a pivotal interconnection
of one steering arm to the other steering arm
in a region offset from the axles in a direction
between the wheel sets and thereby provide for
coordinated pivotal motion of the wheel sets in
the yawing sense and for coordinated interchange
of steering forces between the wheel sets,
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e) and interconnecting the steering arms
to the truck frame members by applying connection
means in regions offset from the axles in a direct
lion longitudinally of the truck opposite to the
direction of offset of the pivotal interconnect
lion of the steering arm, said connection means
serving to restrain relative lateral motion of
the steering arms and truck frame members in said
spaced regions and thereby provide for lateral
displacement of said pivotal interconnection during
coordinated pivotal motion of the wheel sets and
steering arms.
Still further, the present invention provides
a method for retrofitting a powered railroad truck with
mechanism providing for wiliest steering, which method
comprises:
a) selecting an existing truck having load-
carrying side frame members with two pairs of
pedestal jaws each with pedestal liners, two wheel-
sets each comprising a pair of wheels fixed on
an axle having a driving motor and axle hearings
and bearing adapters received in the pairs of
pedestal jaws, the bearing adapters of each pair
having load-carrying spring connection with the
side frame members, and further having brake mock-
anise including a brake cylinder at each snide
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of the truck and brake-operating connections from
each cylinder to the brakes for the two wheels
at that side of the truck,
b) removing at least a part of the pedestal
liners to provide increased freedom for yaw move-
mint of one wiliest with respect: to the other
wiliest,
c) applying a steering arm to each wheel-
set, the steering arms being connected with the
wheel sets to provide for conjoint movement of
each wiliest with its steering arm in fixed rota
lion in the yawing sense,
d) establishing a pivotal interconnection
of one steering arm to the other steering arm
in a region offset from the axles in a direction
between the wheel sets and thereby provide for
coordinated pivotal motion of the wheel sets in
the yawing sense and for coordinated interchange
of steering forces between the wheel sets,
2Q en and altering the brake-operating con-
sections to provide for operating the brakes on
the two wheels of one wiliest by one of the brake
cylinders, and to provide for operating the brakes
on the two wheels of the other wiliest by the
other brake cylinder.
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BRIEF DESCRIPTION OF TEE DRAWINGS:
How the foregoing objects and advantages are
attained, together with others which will occur to those
skilled in the art, will appear more fully from the lot-
lowing description taken with the accompanying drawings,
in which:
Figure 1 is a side elevation Al view of a known
form of powered truck to which the self-steering equipment
of the present invention has been applied, portions of the
structure being broken away and shown in section in the
central region;
Figure 2 is an end view of the truck of Figure
1, with parts in the left hand portion of the view shown
in vertical section;
Figure 3 is an enlarged vertical sectional view
of the flexible joint or connection between two steering
arms;
Figure 4 is a plan view of the truck of Figures
1 to 3 but with certain portions broken away and shown
diagrammatically in horizontal section;
Figure 5 is a somewhat diagrammatic elevation Al
outline view of another embodiment of the equipment of the
present invention applied to a powered truck in order to
establish self-steering in the yaw sense;
I
Figure 6 is an end view of the truck of Figure
5; and
Figure 7 is a plan view of the truck of Figures
5 and 6, with certain parts broken away.
The embodiment illustrated in Figures 1, 2, 3
and 4 represents a form of a powered truck, the general
arrangement of which is known, being a conventional truck
manufactured by General Motors Corporation, and these fig-
uses illustrate that truck retrofitted to incorporate one
embodiment of the structure of the present invention.
Figures 5, 6 and 7 diagrammatically illustrate
the same form of truck but incorporating certain alterna-
live structural embodiments of features of the present in-
mention which may be incorporated in such a truck by retry-
fitting, or which may be embodied in a newly constructed
truck.
DETAILED DESCRIPTION OF FIGURES 1 TO 4:
The powered truck of Figures 1 to 4, as above
mentioned, is a known general form of powered truck and
embodies two axle wheel sets, each being provided with a
separate driving motor mounted on the axle of that wheel-
set. At least one such truck is adapted to be positioned
under the body of the vehicle or locomotive, and the general
arrangement of the principal parts of the truck are men-
toned horribly with reference to Figures 1 to 4 inclusive.
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I I
In Figure 2, a portion of the booty of the logo-
motive appears at 12. The body of the locomotive is carried
by the truck through a central pivot structure 13, received
in an upwardly open socket 14 provided on the bolster 15.
The main frame structure of the truck comprises
side frame elements 16, and the weight or load of the logo
motive is transferred from the bolster 15 to the main side
frame elements 16. For this purpose, a swing hanger yoke
17 at each side of the truck having upwardly projecting
spaced legs is pivotal connected with one of the side
frame elements at the points indicated at 18-18, and a
spring plank 19 has its ends received on the base portions
of the yokes 17 at opposite sides of the truck. Rubber
or other resilient cushions 20 are interposed between the
laterally projecting ends of the bolster 15 and the spring
plank, so that the weight of the vehicle is transmitted
from the bolster through the resilient cushions 20 to the
spring plank and thence through the pivotal yokes 17 to
the main side frame elements or members 16. The load is
transferred from the side frames to the wheel sets in the
manner brought out below
In certain existing trucks of the general type
disclosed in Figures 1 to 4, transversely extended leaf
springs are positioned between the bolster 15 and the spring
plank 19; and in such trucks, the retrofitting contemplated
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by the present invention includes either replacing such
leaf springs with rubber cushions of the type indicated
at ED in Figure 2 or retrofitting with the arrangement shown
in Figures 5, 6 and 7.
Each side frame member is provided with two pairs
of pedestal jaws 21-21, each pair receiving the bearing
structure 22 for the outboard portions of the axle of each
wiliest. The bearing structures each comprise roller bear-
ins in bearing boxes; but these parts form no part of the
present invention per so and are, therefore, not illustrated
in detail herein. Instead, the bearing structures are shown
either in outline only, or for the wiliest toward the left
of Figure 4 by a diagrammatic horizontal sectional illustra-
lion.
Each axle is, of course, located centrally in
its bearing structure for instance, in the region indicated
at 23 in Figure 1. A pair of wheels 24 is fixed on the
axle of each wiliest, and these wheels are customarily
flanged and arranged to travel upon rails, such as indicated
at 25 in Figure 2. At each bearing location, appropriate
suspension springs 26 are provided through which the weight
of the locomotive is transmitted from the side frame members
to the bearing structures 22, and thence to the outboard
end portions of the axle of each wiliest.
I
Between the wheels of each wiliest and mounted
upon the axle of that wiliest, a driving motor and gear-
in are arranged, as diagrammatically indicated at 27.
These motors are of known construction and are connected
with the axle of the wiliest with which the motor is also-
elated, and the details of that motor arrangement and con-
section are not described herein as they form no part of
the present invention per so.
As seen in Figures 1 and 4, a pair of transversely
extending longitudinally spaced truck transoms 28 extend
between the side frame members 16 in a portion of the truck
structure in the mid region of the truck; and in addition,
a transom 29 extends between the side frame members at each
end of the truck. The side frame members and those transoms
thus provide truck structure surrounding the region in which
each wiliest and its motor are positioned. With the side
frame members and the various transoms, it will be seen
that the frame of the truck comprises a unified rigid struck
lure, which is in contrast with many other railway railway
car trucks, in which the trucks are provided with independent
side frames capable of various motions with respect to each
other. The interconnected rigid frame structure is cuss
tomarily used in powered trucks of locomotives, especially
where individual motors are provided on each of a plurality
of wheel sets associated with the truck frame.
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Lo
As appears in Figures 1 and 2, the motor also-
elated with each wiliest is supported in part by certain
inter engaging motor nose suspension parts provided on the
motor structure and on the adjoining transom 28. The transom
28 at each side of the central region carries a pair of
motor nose cushion sandwiches 30 formed of interleaved rub-
bier and metal layers located relative to the transom 28
by bolts aye. Abutment lugs 31 and aye project from the
motor structure and transom respectively and serve to in-
terchange torque forces between the motor and the transom through the cushion sandwiches 30. This motor nose sup-
pension means is present on the truck being retrofitted.
The portions of the truck of the embodiment of
Figures 1 to 4, as described above, are all included in
the basic truck structure above referred to as manufactured
by the General Motors Corporation; and it is a truck of
that known construction which is adapted to be retrofitted
according to the present invention in order to incorporate
the self-steering features as applied to the motorized axles
and wheel sets of that prior known truck. In carrying out
the invention, it is, of course, also possible to apply
the invention to a truck being newly built, without retry-
fitting an existing basic structure.
Attention is now directed to various features
of the self-steering mechanisms incorporated in a truck
according to the embodiment shown in Figures 1 to 4 inkwell-
size, and it is here noted that certain new devices and
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structures are added to the equipment; and in addition,
where retrofitting is being effected, certain of the exist-
in components, for instance, the brake arrangements, are
modified in order to provide effective brake operation in
the self-steering type of powered truck contemplated accord-
in to the invention.
It is first noted that, as clearly appears in
Figure 4, substantial clearance is needed between the pedestal
jaws 21 and the bearing structures 22 associated with each
wiliest. This clearance provides freedom for relative
angling or yawing of the wheel sets with respect to the main
truck frame structure. In the case of retrofitting, the
clearance may be provided by removing pedestal liners which
are ordinarily present in such a truck. If desired, the
pedestal liners may either be replaced with pedestal liners
of smaller thickness, or the original liners may be ground
to provide a thinner liner and, therefore, provide the no
squired clearance. The liners are customarily of channel
shape, in view of which removal thereof not only provides
clearance in the fore-and-aft direction but also transversely
of the truck. It is pointed out that the lateral movement
restraint of certain roller-bearing arrangements normally
provided by limiting the lateral pedestal clearance is pro-
voided in the arrangement of the present invention by the
connection of the wheel sets to the steering arms described
below.
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The self-steering truck according to Figures 1
to 4, whether retrofitted or newly constructed, incorporates
a "steering arm" for each wiliest. Herein, this term
"steering arm" is used to identify the structure associated
with each wiliest which is required in order to provide
for the self-steering function; and it is to be understood
that this structure may take a variety of different forms.
Thus, it may comprise a transverse bar having an arm ox-
tended from each end toward the axle, or it may comprise
a structure or yoke extended around the entire wiliest,
as it the case in the illustration of figures 1 to 4.
Unless otherwise indicated, the term "steering arm" as used
herein is to be understood in a generic sense.
Each of the steering arms comprises several dip-
fervent but interconnected structural pieces. Thus, a long-
tudinally extending channel or beam 32 extends fore-and-
aft of the truck in the region of each bearing structure
22 and is secured to that bearing structure as indicated
at 33. The outer ends of each pair of channel members 32
are interconnected by a transversely extending tube or brace
34. The yoke or steering arm for each wiliest further
includes inwardly converging portions 35 which are inter-
connected by a transverse beam 36. The steering arm of
this embodiment includes the parts identified by the rev-
erroneous numerals 32, 34, 35 and 36 thus constitutes a yoke
completely surrounding each wiliest.
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The two steering arms are interconnected by means
of a pivot structure which is preferably located in the
central region of the longitudinal and transverse axes of
the truck. As best seen in Figure 3, this interconnection
between the transverse beams 36 and 36 of the two steering
arms comprises a central vertical pin 37 which is mounted
by means of plates 38 secured to one of the beams 36. The
pin 37 serves to mount a central ball element 39, with its
outer curved surface received in a socket 40 provided on
the other transverse beam 36. A rubber or resilient liner
41 is provided between the spherical surfaces of the ball
39 and the socket 40; and as is clearly seen in the claw-
inks clearances are provided so that the interconnected
steering arms for the two wheel sets may not only partial-
pate in relative yawing motions, but may also participate
in other relative motions, including relative lateral and
longitudinal tilting of the steering arms and thus of the
wheel sets.
Since the side frames of this general type of
truck structure are interconnected and the truck f faming
has rigidity it becomes practical to employ a form of trays-
verse link 7 interconnection between the steering arms and
the truck frame. This connection is arranged in a manner
which will not interfere with the desired relative yawing
motion of the two steering arms and the associated wheel-
sets. In the embodiment shown in Figures 1 to 4, the
~3~7~
connection also constitutes a portion of the retrofitting
equipment, in the event the arrangement is being applied
to an existing truck. The connection comprises a generally
transverse link 42 for each steering arm, the link having
a connecting joint 43 a one end through which the link
is connected with the steering arm, and also having a con-
netting joint 44 between the other end of the link and the
cross transom member 29 of the truck frame. Preferably,
each of the connecting joints is flexible to accommodate
I relative angling of the steering arms and truck frame struck
lure. Desirably, these joints include resilient components
to absorb minor relative motions and vibrations.
Because of the presence of these links, when the
truck enters a curve and yawing forces are intercommunicated
between the two steering arms through the interconnecting
joint formed of the parts identified as 37 to 41, the rota-
live yawing motion of the links is accommodated by a slight
shifting movement of the interconnecting joint transversely
of the truck. At the same time, because of the arrangement
and characteristics of the interconnecting joint as above
described, that joint will not only accommodate the relative
yawing motion of the steering arms and thus of the wheel sets
in the yawing sense, but will also accommodate other rota-
live motions of the steering arms and wheel sets, particularly
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relative lateral and longitudinal tilting motions thereof.
This form of transverse link interconnection between the
truck frame having rigidly interconnected side frame members
and the steering arm not only serves the functions referred
to above, but is of particular importance in maintaining
stability of operation at high speeds.
In accordance with the embodiment disclosed in
Figures 1 to 4, special provision is made for interchange
of the motor inactive forces from the steering arms to the
truck frame, notwithstanding the relative yawing or steer-
in of the axles For this purpose, see particularly Fig-
uses 1 and 4, the cross beam 36 of each steering arm is
provided with an abutment pad 45, being presented toward
a cooperating pad 46 which is applied to the surface of
the truck transom 28 presented toward the cross beam 360
As seen in Figure 4, these abutment pads are provided at
both sides of the central joint interconnecting the steer-
in arms Because of this arrangement, the inactive effort
generated by the motor associated with a given wiliest
will be communicated to the truck frame through the steer-
in arm for that wiliest and thence through the pair of
abutment pads 45 and 46. When the truck is being driven
in one direction, for instance, toward the right when viewed
as in Figure 4, the inactive force generated by the motor-
iced wiliest toward the left of Figure 4 will be commune-
acted through the steering arm for the left wiliest to
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I
and through the central interconnecting joint between the
two steering arms and thence through the abutment pads 45
and 46 at the right hand side of the central joint. When
the vehicle is being power driven in the opposite direction,
the abutment pads 45 and 46 at the left of the central joint
as viewed in Figure 4, will receive the inactive force of
both wheel sets and communicate that force to the truck frame
through the transom 28 positioned at the left of the central
joint.
It is contemplated that the abutment pads 45 and
46 be arranged to maintain surace-to-surface contact not-
withstanding yawing as well as other angular motions of
the steering arms. For this purpose, rubber pads may be
used under the metal abutment pads. Alternatively, the
abutment pads may be formed of a material having resilient
characteristics as well as wear resistance. For this pun-
pose, the pads may be formed of polyurethane.
A known truck of the general construction shown
in Figures 1 to 4 also incorporates brake cylinders 47 and
48, one being mounted toward one end of the truck frame
at one side thereof, and the other being mounted toward
the other end of the truck frame toward the opposite end
thereof, as clearly appears in Figure 4. In a truck of
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the kind referred to and adapted to be retrofitted accord-
in to the present invention, the brake-applying cylinder
47 is provided with brake-operating links and levers ox-
tended to the two brake shoes 49 and 50 associated with
the wheels 24 toward one side of the truck frame: and the
other brake-applying cylinder 48 is provided with brake-
operating links and levers extended to the two brake shoes
51 and 52 associated with the wheels 24 positioned toward
the opposite side of the truck frame. Because of the in-
lo production of the steering arms and the consequent steering motions between the two wheel sets, the present invention
contemplates changing the brake rigging in order to provide
for the application of the brake shoes I and 51 associated
with one wiliest under the influence of one brake-applying
cylinder 47; and in order to provide for the application
of the brake shoes 50 and 52 associated with the other wheel-
set under the influence of the other brake-applying cylinder
4B. The retrofitting to effect this change is desirable
to limit the travel of the pistons in the brake-applying
cylinders 47 and 48. The effective range of travel would
be likely to be exceeded if the original brake rigging was
retained in the truck modified to introduce the steering
arms. however) with the retrofitted brake rigging arrange-
mint, the brake cylinder travel is not increased by the
steering or yawing motions of the wiliest.
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rrJ~ 9
AL
The retrofit brake rigging may be of various
kinds; but in a typical example, such as illustrated in
Figures 1 to 4, the cylinder 47 is connected with a gent
orally horizontal lever 53 pivoted on the top of the side
frame of the truck as indicated at 54 in Figure 4, the inner
end of the lever 53 being flexibly connected wit to the up-
right lever 55 see Figure 1) on which the brake shoe 49
is mounted by the joint indicated at 56. This joint also
connects the lever 62 with the brake shoe, and the lever
62 is pivoted to the side frame as shown in Figure 1, thereby
providing for vertical and lateral support of the brake
shoe in the proper position to contact the wheel. A link
57 extends generally horizontally longitudinally of the
truck from the lower end of the upright lever 55 and, in
turn, is connected with one end of the transverse lever
58 which is pivotal mounted at 59 to a downwardly pro-
jetting portion 60 of a frame transom as appears in Figure
2. The other end of the lever 58 is connected by the link
61 (see Figure 4) with the low r end of the upright brake-
I applying lever aye on which the brake shoe 51 at the other side of the truck is mounted in the same general manner
as the shoe 49 is mounted on the lever 55. The lever aye,
however, is preferably pivotal mounted on the adjacent
side frame member, for instance, in the manner shown for
the lever aye for the other wiliest appearing toward the
right of Figure 1.
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I
Similar brake parts are provided in the intercom-
section of the cylinder 48 with the brake shoes 52 and 50
for the other wiliest.
Wheel sanders 63 may be provided as shown in Fig-
use 1, and in a truck embodying the steering arms are pro-
fireball mounted on a portion of the steering arms, for in
stance, on the transverse beams 34 above referred to. In
the retrofitting of a known truck, it is preferred to no-
locate the sanders from mounting on a portion of the truck
frame to a mounting on a portion of the steering arms.
Four damper devices such as indicated at 64 are
also desirably applied, for instance, two at each end of
the truck between portions of the main frame and portions
of the steering arms, as clearly shown in Figure 1. These
damper devices are connected to the frame and steering arms
by flexible joints adapted to accommodate the relative angle
in motions of the steering arms. These dampers serve to
control the vertical, roll and pitching motions of the logo-
motive car body and the truck frame. It should be noted
that four dampers are shown rather than the customary two
only at diagonally opposite corners of the main truck frame.
The two additional dampers are needed in large part because
pedestal/bearing box friction is eliminated by the use of
steering arms. It should also be noted that the combination
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I
of steering arms and four dampers will improve the logo-
motive ride quality because pedestal/bearing box friction
varies widely and it often not adequate to control ride.
This friction also can cause unwanted wheel lift under full
power conditions, adding to the derailment hazard.
DETAILED DESCRIPTION OF FIGURES, 6 AND 7:
Thy embodiment of the self-steering mechanism
shown in Figures 5, 6 and 7, although differing structurally
from the embodiment of Figures 1 to 4, is also capable of
I being used in a retrofitting operation on a truck of the
same kind as referred to above in connection with the descrip-
lion of Figures 1 to 40 The mechanism of Figures 5, 6 and
7 is also capable of use in newly constructed trucks of
various forms. This arrangement offers the potential for
employing strotlger steering arms which can accommodate the
motor nose suspension forces and even completely support
the traction motor.
It is first noted that in Figure 5, the truck
side frame member shown and identified by the numeral 16
I is of the same general configuration as the truck side frames
of the truck being retrofitted in the first embodiment.
However, in Figures 5, 6 and 7, the frame and various
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~3~7~
other parts are shown in much more simplified or diagram-
matte fashion; and in addition, many components of the truck
shown in Figures 1 to 4 have been completely omitted from
the illustrations in Figures 5, 6 and 7. It is to be under-
stood that the following description of the second embody-
mint is given with respect to the showing in Figures S,
6 and 7, even though those figure numbers are not spy-
focally referred to.
As in the first embodiment, the steering arms
of the second embodiment also comprise yoke structures sun
rounding the wheel sets and motors. The wheels are India
acted by the numeral 24 and the axle of each wiliest is
here diagrammatically indicated at 65, the motors being
shown in dotted outline at 27, as in the first embodiment.
The wheels are again shown as riding upon the rails 25.
The yoke comprising each steering arm is India
acted at 66. Here the yoke is positioned with its side
legs underlying the journal bearings 67 and is fastened
to the journal bearings, for instance, as diagrammatically
indicated at 68.
In this embodiment, the load is also transmitted
from the side frames to the Journal bearings by means of
springs, in this instance comprising helical springs 69;
-24-
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and it will be noted that clearance is again provided in
the pedestal jaws so that the yaw and other relative angular
motions may occur without undesirable restriction. It should
also be understood that with the stronger steering arms,
the springs could be located alongside the axle boxes and
the weight could be carried from the springs to the bearing
boxes through the steering arms.
In this second embodiment, the interconnection
between the steering arms takes a different structural form
which permits using the space in the center of the truck
for secondary suspension parts such as leaf springs or for
other purposes. However, as in the first form, the inter-
connection means provides freedom for relative pivotal
motion of the steering arms and thus of the wheel sets in
the yawing sense, but instead of employing a centrally
located ball or pivot joint, the two steering arms are
pivotal interconnected with a centrally located inter-
mediate member or plate 700 Each steering arm 66 is con-
netted with the plate 70 by a pivot joint diagrammatically
indicated at 71. The plate 70 is suspended from the main
truck framing by means of upright connecting rods 72. These
rods have flexible joints 73 at their upper ends suspending
the rods from the main truck framing and further have flex-
isle joints 74 at their lower ends connecting the rods with
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~3~73L
the plate 70. Because of this arrangement, the connecting
plate 70 has freedom for motion laterally in a horizontal
plane. Yaw motion of the plate is prevented by the pair
of guide rods 75. Thus, the relative motions of the steer-
in arms which are connected with the plate by the flexible
joints 71 are constrained in the same manner as would be
the case if they were connected directly to one another
as by a pivot joint 37 in the first embodiment.
In view of the arrangement just described, tree-
lion forces are communicated from steering arms to the eon-
trial plate 70. Those forces are, in turn, communicated
to the main frame structure also by means of the rods 75,
one disposed toward each side of the truck frame and being
connected at one end by flexible joints 76 with brackets
77 which, in turn, are connected with the truck side frames.
The other ends of the rods 75 have flexible joints 73 servo
in to connect the rods with the brackets 79 which are mounted
on the plate 70. Thus, the plate 70 acts to interchange
steering forces between the two steering arms and to carry
traction forces from the steering arms to the truck frame.
Torque forces are communicated between the motor
27 and the steering arm of each wiliest by means of spaced
abutment lugs 80, one projecting from the motor above the
steering arm and tube other projecting from the motor below
-26-
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the steering arm, as shown in Figure 5. The torque forces
are communicated to the plate 70 and from that plate through
the links 72 to the rigid truck frame. It can be visualized
that the motor could be supported entirely by extending
the motor 27 in the region 87 and providing for connection
to the steering arm cross member 82 mentioned horribly.
It is further contemplated to employ generally
horizontal links 81 at opposite ends of the truck, each
link providing for interconnection of the adjacent steer-
in arm and the adjacent transom of the truck frame, the latter being indicated at 82. Flexible connections 83 and
84 at the ends of each link 81 are associated with brackets
85 and 86 which are mounted respectively on the adjacent
steering arm 66 and on the adjacent transom 82.
Because of the links 81/ tube relative yawing
motions of the two steering arms are accompanied by trays-
verse motion of the interconnecting plate 70 with which
the steering arms are joined by the flexible connections
71. This transverse motion is similar to that of pivot
37 in the first embodiment.
It is to be understood that a variety of car body/truck
interconnections could be used with bolster means such as
illustrated and described in connection with the first embody-
mint are present in the event that the truck of Figures
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I .
5, 6 and 7 is being retrofitted to an existing truck struck
lure, as referred to in Figures 1, 2, 3 and 4. Other parts
and devices will, of course, also be used, including for
example brakes arranged as described above in relation to
Figures l to 4, but various of these additional parts are
not shown and described in detail with reference to the
embodiments of Figures 5, 6 and 7.
It will be noted that in Figures 5 and 7, certain
distances are marked, being identified by the letters a
and b. The distance a represents the spacing from the center
of the axle to the point of connection 71 of the steering
arm with the plate 70. This spacing should be the same
for each of the two motorized wheel sets, but the spacing
b between the pivot joints 71 for the two steering arms
may be different from the spacing a and is not critical.
It is further noted that with distance b made approximately
equal Jo pa, the embodiment can be used on a three-axle
truck with the third motor/axle assembly moving laterally
with plate 70.
CONCLUSION:
. . _
The foregoing description of the two embodiments
shown in the drawings discloses novel arrangements for pro-
voiding a self-steering function in multiple axle powered
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I
locomotive trucks. This results in greatly increased occur-
cay of tracking of the wheels, with consequent extensive
increase in wheel adhesion. This not only eliminates us-
desirable wheel flange/rail forces on curved track and also
virtually eliminates high-speed hunting, with the resultant
excessive wear on both road bed and trucks, but in addition,
these various improvements in the operation of the powered
truck result in greatly increased traction available from
a given input of power.
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