CA1153626A - Truck for railroad car - Google Patents

Abstract

Case 5754 TRUCK FOR RAILROAD CAR

ABSTRACT OF TEE DISCLOSURE
A railroad car truck comprising spaced wheelsets has axle ends of each wheelset journaled in bearings which in turn are carried respectively by an adapter. Each adapter is connected to z side portion of a U-shaped steering arm so as to form a wheelset-steering arm unit. Resilient pads join the side portions of the steering arms to pedestal jaws formed at ends of a pair of spaced side frames. The resilient pads allow each wheelset-side frame unit to move toward a position which is substantially aligned with track over which the truck may travel. Movements of each wheelset-steering arm unit are selectively regulated by a connecting device joining the steering arms at a central location proximate to a bolster or the truck.

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Description

1~53626 BACXGROUND OF TH~ INVENTTON
Field or the Invention This invention relates to railroad car trucks wherein wheelsets of the truck may move toward a position OL- align-ment with the track over which the truck is traveling and more particularly with a connecting devlce o~eratively joinlng the wheelsets to regulate such movements.
Prior Art ~ odern railroad car trucks are commcnly referred to as three-piece trucks which i~clude spaced side frames resil-i~ntly su~porting therebetween a transversely positioned bolster. The bolster contains a centerplate which in turn supports a body of the railroad czr. The side frames have downward projecting jaws in which axle ends of a rront and a rear wheelset are rotatively journaled. Such trucks may also be described as nonsteerable in that the bolster, side frame and wheelsets are purposefully maintained in a squared relatlonship.
Steerable trucks, on the other hand, are ones having wheelsets which may yaw, for example. Such trucks are well known and one ty~ical type is disclosed in U.S. ~atent No. 3,789,770. As disclosed, this truck allows rotation of each wheelset about its vertical axls so that the wheelset may take an out-o -square position with respec. to a longi-tudinal axis or the truck. The wheelsets are joined by positive mechanical linkage whlch controls and malntains the relationshi2 between the wheelsets. Additionally, this linkage iS connectec to a body o_ the ~ailroad car so that movement between the car body and the wheelsets is malntained in a -ixed rela~ionshi?.

1~536%~i Providing a flexible connection between the axle ends ~',, of the wheelset and tne side frame to allow yawing there-between'is also well known and is disclosed in, for examDle, , U.S. Patent No. 3,785,298. In this case, a resilient or ; elastomeric device interfaces between pedes~l jaws of a side frame of the t-uck and axle ends of the wheelsets to allow lim~ted movement therebetween which is -es,rained by ~' the elastomeric device.
U.S. Patent No. 3,528,37~ discloses a truck which is one or the first to adapt steering principles to the modern day three-piece truck. In this instance, a bolster has its ends resiliently carried by side frames. Ends of the side frames are adapted to allow the whee,lsets o~ the truck to ', yaw. Yawing in turn is regulated by parallel elastic bracing members connecting aligned f~ont and rear axle ends and diagonally positioned elastic bracing members connecting opposite front and rear axle ends. A substantially ldentical concept and structure is utilized in the BARBER-SC~FFEL
~igh Speed Radial Truck presently being offered for sale by Standard Car Truck Company or Chicago, Illinois.
,~ A further arrangement to provide a truck with wheelsets -' which can yaw so as to maintain an allgned rela~ionship with ; the track,on which the truck is traveling is disclosed by U.S. Patent No. 4,003,316. As so disclosed, holding frames which-carry the axle ends of the wheelsets are individually connected to a bolster of the truck through a ball bearing socket arransement enclosed in a pad. .~ny lateral movement of the bolsier effects a rotational mov~ment of the holding frame and thus the wheelsets.

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~L~536~Z6 Most recent developments in steerable ~rucks are perha~s disclosed in U.S. ~atent Nos. 4,067,261 znd 4,067,069. The '261 ~atent discloses as its preferred embodiment a-t-uck ~uite similar to the comme-cially available truck noted above. Particular emphasis is placed on the use of wheels having highly profiled wheel treads to generate steering forces. A pair of U-shaped suDframes carries the axle ends o~ each wheelset and may be interconnected by a pair or dia~onally positioned rods. These rods may, in turn, be joined through a dampenlng device.
The '069 patent discloses 2 further steerzble railroad car truck wherein resilient means of predetermined stiffness interconnect .he axle ends carrying subfr~mes or the truck at a centrally located point. Additionally, resilient means interconnect the subframes with the side frames of the ~ruck and the truck with a body of the car. The DR-l Steering Assembly Truck commercially available from Dresser Industries, Inc., of Depew, New Yor~, appears to embody many of the teachings found in this patent.

SUMMARY OP T~E INVENTION
A railroad truck of this invention includes a pair of spaced side frames each having a front and rear downward projecting pedestal jaw. Resiliently car,ied by the pair of side fr~mes at midpoints thereor are ends OL a t_ansversely positioned bolster which in turn supDort there bove a body of a railroad car.
Within the ront pedestal jaws o the side frames are side Dortions of a U-sha~ed front stee-ins arm while a like rear steerins arm has its side ~ortions ~ositioned within ~s~ ~7~4!

l~S3~26 the rear jaws of the two side f_ames. Interfacing bet~een a top surface of the side portions or each st2erins a~m and a bottom surface of each pedestal jaw of the side frames is an elastomeric device.
Each wheelset of the truck has its axle ends rotatively journaled in bearings carried respectively by an adzpter which in turn connects respectively with the side portion of the steering arms. Thus, each wheelset and respective steering arm is rormed into an integral unit.
The~elastomeric device allows each wheelset-ste~ring arm unit to react to dynamic forces created during travel of the truck and move to a new position in response to these i:
oxces. These movements are multi-directional in na-ture and occur-continuously.
These movements are in part regulated by a connecting device which joins the two wheelset-steering arm units.
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- Protruding inwardly rrom a middle part of each steering arm is a bracket. An inner end of each bracket is joined by the connecting device which includes a linkage bar which connec.s with-each bracket through two spherical bearing sets and a ; vertically disposed pin which passes through each bracket and bearing set. This connecting device may be located within a center ~avity specirically provided for such in tne bolster of the truck. During movement of the wheelset-steering arm unit, the connecting device remains independent or the bolster in that the center cavity provides a clear passage therethrough.
The truck of this invention has seve~al import~nt advantages over both nonsteerable trucks and steerable trucks presently known.

~lS36;Z6 - -Nonsteerable t-ucks inhibit yawing mov~ments of the wheelsets. Known steerable trucks allow some movement which until now was controlled by some resilient device or by positive mechanical linkage connectina the rront and rear S wheelsets.
I~ nonsteerable trucks, wear of the wheelsets is advanced by sli?page between the wheelset and the track which occurs as the truck traverses a curve. In known ; steerable trucks controlled solely by resilient devices, increased wheelset movement is opposed by an ever increasing restoring force.
On the other hand, this railroad car truck provides means allowing each wheelset to react independently to directional changes in the track on which the railroad car is traveling. For example, when the truck encounters a . . .
left-hand curve in the track, the forwardmost or front wheelset tends to rotate cou~terclockwise about its vertical axis, i.e. yaw, while moments later the rear wheelset likewise tends to rotate counterclockwise a~out its ver,ical axis. However, the amount o rotatlon of each wheelset is unequal so that the wheelsets move from a parallel to a :
nonDarallel ?osition. This rotational tendency is created by the conriguration of the outer sur-ace or the wheels ; interacting with the track. Because most such c~rves are also ban~ed to allow higher speed travel, the wheelset also ; rotates about the longitudinal axis of the truck, i.e. roll.
These yawing and rolling movements of the wheelsets and thus the wheelset-steering arm units are independent in nature. The connecting device selec'ively accommoàates :.

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certain or these independent movements while at the same time inhibitlng other movements. Additionally, the connecting device, once 2ssembled, resists disassembly durins truck operation.
Thus, this truck provides superior performance by allowing multi-directional wheelset movemen,. Such movements are regulated in part by the elastomeric devices and the connecting device between the wheelset-steering arm units.
As a resul't, wheel wear is reduced and the dynamic stability of the truc~ is improved during hlgh speed, heavy load and rough road bed operation.

BRIEF DESCRIPTIO~ OF T~E DRAWINGS
FIG. 1 is a plzn view of a railroad car truck incorpo-rating this invention.
FIG. 2 is a side elevational vlew in partlal section of the truck of EIG. 1.
FIG. 3 is a detailed plan view of a portion or the steering arm of the truck of FIG. 1 wherein the anms are joined by a connecting device.
FIG. 4 is 2 cross-sectlonal view of the connectirg devlce as gene~ally seen along the line 4-4 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENT
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A railroad car truck is shown generally at 10 and includes a front wheelset 12 and a rear wheelset 14. The ; Cront wneelset 12 has axle ends 16 journaled in rront wheel bearings 18 while in a like manner the rear wheelset 14 has

2; axle ends Z0 journaled in rear wheel be~ring 22. It should ~ 536Z6 be understood that the truck 10 is bi-directional, and the terms "rront" and "rear" are used to more convenlently describe the truck 10.
~itted over a top portion of each bearing 18, 22 is an ; adapter. ~ront adapters are designated 24 and rear adapters 26. The adapters 24, 26 each have an annular boss which projects u~wardly from an upper side thereof. Supported on the front adapters 24 is a front-steering arm 28 while thé
rear adapters 26 carry a rear steering arm 30~
Each ~L- the front and rear steering arms 28, 30 is generally U-shaped and comprises a middle portion 32 connec-ting with Z-shaped side portions 34. On an underside of ~`i each side portion 34 at its outer end 36 is an annular recess which mates with the boss of the adapters 24, 26 so as to join the steering arms 28, 30 with respective wheelsets 12, 14 into a front and a rear unit or combination 35, 37.

. , On an upper surface of each steering arm side portion outer end 36 is an upwardly facing recess 38 in which is ~- fitted zn elastomeric device 40. An u?per portion or each 2 elastomeric device 40 in turn fits withln a downwardlv facing recess 42 formed in a roof portion o. 2 front and a rear pedestal jaw 46, 48 of a pair OI s~aced lert, right side frames 50, 52.
Each side frame 50, 52 has a centrally located window 25 ;4 to receive an end 56 or a transve-sely positioned bolster :~, 58~ The ends 56 of the bolster 58 are resilien.ly s~2oor~ec C~s~ ~754 ~53~6 .
,~, on sets of coil springs 60 in a known manner. FIG. 2 shows one such resilient connection between the side frame 52 and the bolster 58, and it should be understood that connection between the bolster 58 on the side frame 50 is similar.
To dampen ver~ical oscillating related to coil spring suspension, a pair of friction snubbing devices 62 interacts ,; between the bolster ends 56 and vertical wear plates 64 carried on s,paced sides 66 of each side frame window 54.
The bolster 58 includes an integrally formed cente_ plate 68 which connects with a body or the railroad car ~not shown) in a known manner. Below the centerplate 68 in the bolster 58 is a cavity 70 providing a clear horizontal passage through a center of the bolster 58. One preferred ~bodiment of such a bolster center cavity 70 is set rorth-in U.S. Patent No. 4,114,540. The truck l0 further includes f-ont and rear braking means 72, 74 which is discussed in , greater detail subsequently.
On the middle part 32 of the front and rear steering arms 28, 30 is a bracket 76 which forms part of a connecting means 78 between the front and rear wheelset-steering arm units 35, 37. The brackets 76 project into the bolster center cavity 70 in an opposing manner as is best understood by viewing FIGS. l and 3.
Ends 80 of each ~racket 76 lie adjacent to and on ,, .
` 25 ' opposlte sides of a ver.ical plane passing through a longi-tudinal axis Ld of the,truck 10. Each bracXet end 80 is bifurcated into an upper p ong 82 and a lower ?rong 84.
Sets of vertically aligned apertures 86, 88 2-e .ormed in ', each upper and lower prong ?air 82, 84 of each Dracket end , ~0 80. 7~rnen the ~ront and rear wheelset-steering a~m uni~s " .

~ase 57~4 1~3626 35, 37 are in a sauared relationship with res?ect to the side frzmes 50, 52 and the bols~er 58, the aperture pairs 82, 84 align with a vertical plane which passes throush a lateral axis La of the truck 10.
Pressed into each o~ the apertures 86, 88 is a bushing 90. Horizontally disposed between the upper and lower prongs 82, 8a or each bracket end 80 is an elonga.ed linkage bar 92. Apertures 94, 96 are formed adjacent to ends o~ the bar 92 and are so positioned to align with the apertures 86, 88 in the upper and lower prongs 82, 84 respectively.
- In each bar aperture 94, 96 is a spherical bearing set ; 98 comprising an inner element 100 and an outer element 102.
The outer element 102 has a circular outer wall 104 to rit snugly within the bar apertures 94, 96 and a concave spherical inner wall 106. The inner wall 106 engages in a complementary manner with a convex spherical-shaped outer wall 108 of th_ inner be2ring element 100. The inner bezring element 100 rurther includes an inner circular passage 110.
Disposed through each bushing 90 and through the inner passage 110 of each bearing set 98 is a pin 112. ~ach pin 112 has an enlarged head 114 to limit downward movement and ; a lower cotter pin aperture 116. A cotter pin 118 may be conveniently disposed through lower pin aperture 114 ar.er-assembly to limit upward movement or that pin 112.
Dynamic and static foraes occur~ing during 03era.ion o' the truck 10 results in the wheelset-steering arm units 35, 37 tending to move rotationally and linearly in all three directions 3ecause these rorces vary in cirection and magnitude, the actual movemen's or the wheelset-s~eering ar~
units 35, 37 are lzrgely un?r3dlctable. Yowever, the s-ructu_e _ 9_ Case ~7~4 ~S3~2~i of ~he truck 10 is such that these multi-directional move-ments may be accommodated between sets limited and selec-tively regulated to the degree~that certain movements are predictable.
As may be more easily understood by viewing FIG. 4, either wheelset-steering arm combination 3~, 37 may move vertically, pitch or roll without such movements being impeded by the connecting device 78. Such mov~ments of each unit 35, 37 may be out-of-phase, i.e. in the same direction, or in-phase, i.e. in the opposite direction. Regardless, each unit 35, 37 is not restrained by the other 'hrough the connecting device 78. Thus, the wheelset 12, 14 of either unit 35, 37 may move to a more aligned position with the track over which the wheelset 12, 14 is in contact to accommodate for variation in track direction and rail height.
~o~ever, certain horizontal and yawing movements of the wheelset-steering arm unlts 35, 37 are restrained by the connectins device 78. For example, all in-phase horizontal movements or the units 35, 37 which align wi~h the lateral axis La of the truck 10 are inhibited by the connecting device 78. Likewise, in-phase yawing movements of the units 35, 37 are inhibited by the connecting device 78. Yawing o~
the wheelset-steering arm units 35, 37 occurs when the ~ruck 10 proceeds about a curved section of track. Such yawi~g of the units 35, 37 is maintained in an exact out-o--pha~e relationship by the connecting ~evice 78.
Inhibiting in-phase yawing movement of tne units 35, 37 is particularly im?ortant to maintain proper dynamic stabilitv of the truc~ 10. ~or example, during travel, ~e side frame 50, 52 tends to lozenge, i.e. the side L-ames 5~, 52 remain 1n-~536Z~

parallel but move ~o a longitudinzlly orfset position, under dynamically induced forces. ~or lozenging to occur, one wheelset-steering arm unit, for example the front unit 35, must move in one di-ection while the rear wheelset-steering i arm unit 37 must move in the opoosite direction or move in-phase. Lozenging reduces the critical speed of the ,ruc~ 10 wherein the wheelsets 12, 14 tend to hunt, i.e. dynamically induced oscillating about a vertical axis of each wheelset.
The connecting device 78 prohi~its such in-phase movement.
Thus, the side frames 50, 52 are inhlbited from lozenging which in turn maintains the critical speed above that which the truck 10 and associated rzilroad car body is expected to travel.
On the other hand, in-phase or out-o,-phase horizontal L5 movements of the units 35, 37 which are aligned with the longitudinal axis Ld of the truck 10 are not res~rained by the connectlng device 78. Such movements occur when the front and rear braking means 72, 74 are activated.
The braking means 72, 74 is conventional in nature and ~a includes a brake beam 120 with brake shoes 122 supported from outer ends of such for engagement with the front and rear wheelsets 12, 14. Each brake beam 120 pivotally connects with a lower end 124 of a brake lever 126. A tie rod 128 pivotally joins a center portion 130 or each lever 126. An upper end 132 o~ one brake lever 126 may be pivotally joined to a body of the railroad car (not shown) while the upper end 132 of the other ~rake lever 126 is operatively connected to a ~ower device (not shown) by a connec_ing rod 134.
Move.~ent of the connecting rod 134 in the direction O opposite the arrow D in ~IG. 1 fo-ces the brake shoes 122 Cas~ ~7,4 ,. .

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against the wheelsets 12, 14 to move the units 35, 37 .
slightly apart. This slight in-phase movement of the units 35, 37 is not inhibited by the connecting device 78.
Proper mechanical operation of the connecting device 78 is enhanced by placing the device 78 within the protective environment provided by the bolster center cavity 70.
Furthe_, by locating the spherical bearing sets 98- of the linkage bar 92 between the upper and lower prongs 82, 84 of each bracke~ end 80, the bearing sets 78 are shielded r^rom foreign matter associated with railroad car travel.
Likewise, the connecting device 78 may be readily assembled or disassembled to allow periodic maintenance.
~owever, because the connecting device 78 allows each wheelset-steering arm unit 35, 37 to move in a number of directions without regulation of those movements, the - connecting devlce 7~ is not unduly subject to the dynamic force causing those movements. Thus, the connecting device 78 may remain reasonably maintenance free.
A further adva~tage provided by the connecting device 78 is that it is reasonably fail safe frcm disassembly. For such disass~mbly to occur, one of the pins 112 must become ....
disassociated from the linkage bar 9~. Downward movement of each pin 112 is limlted by the pin head 114. Upward move-ment of the pin 112 can only occur upon fallure of the ~S cotter pin 118 and applica.ion of a sufficient force over an opposite gravitational force to cause a lower end of the pi~
112 to move a~ove the linkage bar 92. The liXelihood of -both such events occurrinq is slight indeed.

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While varLous minor modifications may be suggested by those versed in the ar., it should be understood that I wish to embody within the scope of the p2tent warranted hereon ; all such modifications as reasonably and prooerly come wtihln the scope of my contribution to ~e art.

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Claims (2)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A railway truck assembly comprising a pair of laterally spaced side frames, a first wheelset and a second wheelset longitudinally spaced from said first wheelset, each wheelset being connected to said side frames for independent turning movement relative thereto, a first steering arm connected to said first wheelset for movement therewith, a second steering arm connected to said second wheelset for movement therewith, connecting means substantially intermediate said first wheelset and said second wheelset connecting said first steering arm to said second steering arm in side-by-side relationship, said connecting means including laterally spaced pivot means providing vertical turning axes about which said first steering arm and said second steering arm are relatively rotatable and which transmit wheelset turning forces between said first wheelset and said second wheelset.

2. The invention as described in claim 1 wherein said connecting means includes spanning means spanning said first steering arm and said second steering arm, and said laterally spaced pivot means is located to connect said spanning means to said first steering arm and said second steering arm.