CA1146012A - Truck for railroad cars - Google Patents
Truck for railroad carsInfo
- Publication number
- CA1146012A CA1146012A CA000354901A CA354901A CA1146012A CA 1146012 A CA1146012 A CA 1146012A CA 000354901 A CA000354901 A CA 000354901A CA 354901 A CA354901 A CA 354901A CA 1146012 A CA1146012 A CA 1146012A
- Authority
- CA
- Canada
- Prior art keywords
- bracket
- steering arm
- truck
- wheelset
- bolster
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B61—RAILWAYS
- B61F—RAIL VEHICLE SUSPENSIONS, e.g. UNDERFRAMES, BOGIES OR ARRANGEMENTS OF WHEEL AXLES; RAIL VEHICLES FOR USE ON TRACKS OF DIFFERENT WIDTH; PREVENTING DERAILING OF RAIL VEHICLES; WHEEL GUARDS, OBSTRUCTION REMOVERS OR THE LIKE FOR RAIL VEHICLES
- B61F5/00—Constructional details of bogies; Connections between bogies and vehicle underframes; Arrangements or devices for adjusting or allowing self-adjustment of wheel axles or bogies when rounding curves
- B61F5/38—Arrangements or devices for adjusting or allowing self- adjustment of wheel axles or bogies when rounding curves, e.g. sliding axles, swinging axles
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Vehicle Body Suspensions (AREA)
- Steering-Linkage Mechanisms And Four-Wheel Steering (AREA)
Abstract
JLS:pm 6/28 Case 5705 TRUCK FOR RAILROAD CARS
ABSTRACT OF THE DISCLOSURE
A truck for a railroad car has a front and rear wheel-set with axle ends rotatively carried in a front and rear steering arm, respectively. The steering arms are carried in pedestal jaws of a right and left side frame with resilient pads interfacing between the steering arms and the side frames. The resilient pads allow each wheelset and steering arm to rotate or yaw to an out-of-square condition with respect to the side frame as the railroad car proceeds, for example, around a curve in the track on which the car is traveling. This rotational movement is selectively regulated by a joint connecting the front and rear steering arms.
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ABSTRACT OF THE DISCLOSURE
A truck for a railroad car has a front and rear wheel-set with axle ends rotatively carried in a front and rear steering arm, respectively. The steering arms are carried in pedestal jaws of a right and left side frame with resilient pads interfacing between the steering arms and the side frames. The resilient pads allow each wheelset and steering arm to rotate or yaw to an out-of-square condition with respect to the side frame as the railroad car proceeds, for example, around a curve in the track on which the car is traveling. This rotational movement is selectively regulated by a joint connecting the front and rear steering arms.
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Description
. Case 5/05 ~146~1~
BACKGROUND OF THE INVENTION
Field of the Invention This invention relates .o a truck for use with railroad cars and particularly to a truck which allows relative yawing movement between a wheelset of the truck and side frames of the truck as the railroad car proceeds, for example, around a curve in a section of track on which the railroad car is traveling.
Prior Art Today most all railroad car trucks in use include spaced side frames resiliently supporting therebetween a transversely positioned bolster. The bolster contains a centerpla.e which in turn supports a body of the railroad car. The side frames have downward projecting jaws in which axle ends of a front and rear wheelset are rotatively journaled. Such trucks may be referred to as nonsteerable trucks.
Steerable trucks are ones having wheelsets which may yaw. Such trucks are well known and one typical type is disclosed in U.S. Patent No. 3,789,770. As disclosed, this truck allows rotation of each wheelset about its vertical axis so that the wheelset may take an out-of-square position with respect to a longitudinal axis of the truck. The wheelsets are joined by positive mechanical linkage which controls and maintains the relationship between the wheelsets.
Additionally, this linkage is connected to a body of the ~ Case 5705 ~146012 railroad car so that movement between the car body and the wheelsets is maintained in a fixed relationship.
Providing a flexible connection between the axle ends of the wheelset and the side frame to allow yawing there-between is also well known and is disclosed in, for example, U.S. Patent No. 3,785,298. In this case, a resilient or elastomeric device interfaces between pedestal jaws of a side frame of the truck and axle ends of the wheelsets to allow limited movement therebetween which is restrained by the elastomeric device.
U.S. Patent No. 3,528,374 discloses a truck which is perhaps the first to adapt the steering principle to a modern day truck. In this instance, a bolster has its ends resiliently carried by side frames. Ends of the side frames are adapted to allow the wheelsets of the truck to yaw. Yawing in turn is regulated by parallel elastic bracing members connecting aligned front and rear axle ends and diagonally positioned elastic bracing members connecting opposite front and rear axle ends.
A further arrangement to provide a truck with wheelsets which can yaw so as to maintain an aligned relationship with the track on which the truck is traveli~g is disclosed by U.5. Patent No. 4,003,316. As so disclosed, holding frames which carry the axle ends of t~e wheelsets are individually connected to a bolster of the truck through a ball bearing socket arrangement enclosed in a pad. Any lateral movement of the bolster effects a rotational movement of the holding frame and thus the wheelsets.
Most recent development in steerable trucks is perhaps disclosed in U.S. Patent Nos. 4,067,261 and 4,131,069. The - Case 5705 1~L4~0~Z
disclosure of the first patent places particular emphasis on the use of wheels having highly profiled wheel treads to generate steering forces. A pair of U-shaped subframes carries the axle ends of each wheelset and may be inter-connected by a pair of diagonally positioned rods. Theserods may be interconnected through a dampening means.
The 4,131,069 patent discloses a further steerable railroad car truck wherein resilient means of predetermined stiffness interconnects the axle ends carrying subframes of the truck at a centrally located point. Additionally, resilient means interconnect the s-~bframes with the side frames of the truck and the truck with a body of the car.
SUMMARY OF THE 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 supported by the pair of side frames at midpoints thereof are ends of a trans-versely positioned bolster which in turn support thereabove a body of a railroad car.
Within the front pedestal jaws of the side frames are side portions of a U-shaped front steering arm while a like rear steering arm has its side portions positioned within the rear jaws of the two side frames. Interfacing between a top surface of the side portions of each steering arm 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 in the side portions of each steering arm. The elastomeric devices allow the steering Case 5705 ~14601Z
arms and connected wheelsets to yaw or rotate about the vertical axis of the wheelset. When such rotation or yawing occurs, the wheelsets of the truck and steering arms move to an out-of-square position with respect to a longitudinal axis of the truck.
Protruding inwardly from a middle part of each steering arm is a bracket which is positioned parallel to the longi-tudinal axis of the truck and located within a center cavity specifically provided for such in the truck bolster. Inner ends of the brackets form part of a joint or connection with a plurality of spherical washers and a fastener. The joint provides a regulation of the wheelset movement to an out-of-square position which may proximate 1.8 degrees. During such movement to this out-of-square position, the joint remains independent of the bolster in that the center cavity provides a clear passage therethrough. Once in an out-of-square position, the joint provides only a negligible restoring force.
The truck of this invention has several important advantages over both nonsteerable trucks and steerable trucks presently known.
Firstly, the truck of this invention provides means allowing individual wheelsets to more perfectly react to curvature in the track on which the railroad car is traveling.
` 25 For example, when the truck encounters a left-hand curve in the track, the forwardmost or front wheelset will tend to rotate counterclockwise about its vertical axis while the rear wheelset will tend to likewise rotate counterclockwise about its vertical axis. This rotational tendency is created by the configuration o the outer surfaces of the wheels.
Case 5705 1146~)12 Nonsteerable trucks inhibit such rotation. Known steerable trucks allow such rotation which until now was controlled by some resilient device or by positive mechanical linkage connecting the ~ront and rear wheelsets.
In nonsteerable trucks, wear of the wheelsets is not minimized since a certain amount of slippage between the wheelset and the track is required to traverse a curve. In known steerable trucks controlled by resilient devices, increased yawing produces a likewise increased restoring force.
A further advantage of the truck of this invention is the recognition that to minimize wheelset wear, each wheelset must be allowed a certain amount of independent vertical movement with respect to each other wheelset to accommodaté
variations in the vertical height of the track. Such varia-tions occur, for example, between track elements particularly at joints therebetween where there has been rail wear adjacent the joint.
By providing for horizontal rotation of proximately 2 degrees, a certain amount of independent vertical movement, and selectively controlling these movements by the use of the elastomeric pads and the joint between the steering arms, wheelset wear is reduced and the truck provides improved stability by regulation of the various dynamic forces created during travel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the truck of this invention with a partial section through one side frame of the truck.
FIG. 2 is an elevational view of the truck of FIG. 1.
Case 5705 lZ
FIG. 3 is an offset elevational section view along line 3-3 of FIG. 1.
FIG. 4 is a cross-sectional view, which has been rotated 90 degrees, of a connecting joint formed between two steering arms as shown along the line 4-4 of FIG. 1.
FIG. 5 is a detailed sectional view of the side frame-steering arm-wheelset assembly shown in FIG. 3.
FIG. 6 is a plan view of a,further embodiment of the truck of this invention.
FIG. 7 is a side elevational view in partial section of the truck of FIG. 6 as seen generally along the line 7-7 of FIG. 6.
FIG. 8 is a partial cross-sectional view as seen generally along the line 8-8 of FIG. 7.
FIG. 9 is a side elevational view in detail of a side portion of a steering arm used in the truck of FIG. 6.
FIG. lG is a cross-sectional view as seen generally along the line 10-10 of FIG. 9.
FIG. 11 is a ¢ross-sectional view through a further embodiment of the joint between the steering arms.
FIG. 12 is the joint of FIG. 11 wherein the arms have rotated to a nonaligning position.
FIG. 13 is a cross-sectional view as seen generally along the line 13-13 of FIG. 11.
' DESCRIPTION OF THE PREFERRED EMBO~IMENT
A truck of this invention is shown generally at 10 and includes a front wheelset 12 and a rear wheelset 14. The front wheelset 12 has axle ends 16 journaled in front wheel bearings 18 while in a like manner the rear wheelset 14 has - Case 5705 1~4~0iZ
axle ends 20 journaled in rear wheel bearings 22. It should be understood that the truck 10 is nondirectional and "front" and "rear" are used to more conveniently describe the embodiment.
~o secure the position of the front wheelset 12, the front wheel bearings 18 are carried in a downward projecting semi-circular opening 24 formed in a left and a right side portion 28, 30 of a U-shaped front steering arm 32. In a like manner, the rear wheel bearings 22 associated with the rear wheelset 14 are carried in a like downward projecting semi-circular opening 34 formed in a left and a right side portion 38, 40 of a rear U-shaped steering arm 42. The rear steering arm 42 is positioned in an opposing manner with respect to the front steering arm 32 so that a middle part 44 of the front steering arm 32 is opposite a middle part 46 of the rear steering arm 42.
On a top surface 48 of each left and right side portion 28, 30 and 38, 40 of the front and rear steering arms 32 and 42 are upwardly projecting spaced flanges 50 positioned on each side of a rectangular recess 52 containing an elastomeric pad 54. The pad 54 has a rectangular configuration to form a snug fit within the recess 52. The recess 52 has a depth proximating 1/4 of a thickness of the pads 54 so that a top surface 56 of each pad 54 extends above the top surface 48 of the side portions 28 and 30 of the front steering arm 32 and of the side portions 38, 40 of the rear steering arm 42.
The truck 10 further includes a left and a right side frame 58, 60 formed having a front and rear downwardly projecting pedestal jaw 62 at each end of the side frames 58, 60.
Case 5705 lZ
Each pedestal jaw 62 has a roof surface 70 with down-wardly projecting spaced flanges 72 defining in part a rectangular-shaped covering area 74 for the pads 54. Each area 74 has the same proximate size as each recess 52 of the front and rear steering arms 32 and 42. The height of the flanges 72 proximates 1/2 the thickness of the pad 54 so that a space 76 is formed between the flanges 72 of the pedestal jaws 62 and the top surface 48 of each side portion 28, 30.and 38, 40 when the left and right side frames 58 and 60 are assembled to and supported on the pads 54 respectively.
The front and rear steering arms 32, 42 each have a bracket 150 and 152 formed on a side 153 of each middle part 44 and 46 of the front and rear steering arms 32, 42 respec-tively, ~hese brackets 150 and 152 are opposing and offset from a center point of the respective arms 32, 42 so that apertures 154, 156 formed respectively in each bracket 150, 152 at its outer end are horizontally aligned as each bracket 150 and 152 extends into a center cavity 158 formed beneath .a centerplate 160 of a transversely positioned bolster 161.
The bolster 161 in turn has its ends resiliently carried by a set of springs 162 in a window 163 formed in each side frame 58, 60.
The front and rear brackets 150 and 152 form part of a joint 164 which further includes four sets of spherical washers 166, 168, 170 and 172. Each set of washers further comprises one element having a flat outer surface and an inner convex spherical surface which mates with a second element having an inner concave spherical surface and a flat outer surface. In the exemplary embodiment, the convex element has an "a" suffix while the concave element has a Case 5705 1~4601Z
"b" suffix so that, for example, the washer set 166 has a convex element 166a and a concave element 166b. A radius of curvature of the interfacing spherical surfaces of the washer sets 166-172 has been so selected to complement the rotational movement of the steering arms 32, 42.
About each aperture 154 and 156 on each side of the front and rear brackets 150, 152 are circular recesses 174, 176, 178 and 180 in which the washer sets 166, 168, 170 and 172 are respectively disposed. Note that each convex e~ement 166a, 168a, 170a and 172a is oriented toward the center of the joint 164. The connection 164 further includes a bolt 182 inserted through the washer sets 166-172 and the apertures 154 and 156 of the front and rear brackets 150, 152 and held therein by a self-locking nut 184. The bolt 182 and nut 184 are so assembled as to apply a slight compres-sive force to the various joint elements when each wheelset 12, 14 and each steering arm 32, 42 is in a squared relation-ship with respect to the longitudinal axis of the truck.
During travel of the truck 10 over a straight section of track, each wheelset 12, 14-tracks in a straight line path adjusting automatically for variations in track width and deviation from a straight line path. This automatic correction results from an interaction of the wheel tread with the track. Additionally, other deviations are regulated by a flexing of elastomeric pads 54 and the joint 164. This regulation also helps to control hunting of the wheelsets 12, 14 and lozenging of the side frames 58, 60.
During such straight line travel in a direction as shown by an arrow D in FIG. 1, some rolling of the wheelsets 12, 14, i.e. longitudinal rotation of the wheelsets about _g_ Case 5705 114~iVlZ
the longitudinal axis of the truck 10, occurs because of vertical difference in track height. As was noted earlier, such height differences particularly exist adjacent abutting track ends. This rolling movement of each wheelset is transferred to the front and rear steering arms 32, ~2 and regulated by the elastomeric pads 54 and the joint 164 where vertical movement between the spherical elements of the washer sets 166-172 may occur.
Upon first encountering a curved section of track, for example a left-hand curve, the front wheelset 12 of the truck 10 tracks about the curve and thus rotates or yaws counterclockwise about its vertical axis. This rotational movement is transferred to the front steering arm 32 causing a flexing of the front set of elastomeric pads 54 and horizontal movement between the spherical elements of the washer sets 166-172. ~ote that if the curved section is also banked to allow a higher speed of travel thereabout, there is likewise some rolling rotation of the front wheelset 12 and vertical movement between the spherical elements of the washer sets 166-172.
As the front wheelset 12 and the front steering arm 32 continue to rotate counterclockwise, this rotational move-ment is transferred by the front steering arm bracket 150 to the rear steering arm bracket 152 and thus may cause the rear steering arm 42 and rear wheelset 14 to rotate clockwise.
During this rotational movement of the front and the rear steering arm brackets 150, 152, the bolt 182 of the joint 164 moves in a straight line as noted by arrow D' as seen in FIG. 4.
This rotation of the steering arm brackets 150, 152 moves the washer set elements 166a,b-172a,b to a nonaligning Case 5705 ~14~V12 relationship such that the brackets 150, 152, through the washer sets 166-172, may apply some additional force on the bolt 182. This additional force on the bolt 182 helps to regulate the rotation of the steering arms 32, 42 and thus the front and rear wheelsets 12, 14. Note, however, that while the force on the bolt 182 regulates movement from a squared position to a nonsquared position, the bolt 182 only exerts a negligible restoring force.
As the truck 10 leaves the curved section of track to return to another straight section, the front wheelset 12 tracks clockwise causing the front steering arm 32 and the attached bracket 150 to likewise rotate clockwise. This clockwise rotation is transferred by the brackets 150, 152 and the washer sets 166-172 causing a counterclockwise rotation of the rear steering arm 42 and rear wheelset 14.
The joint 164 thus moves in a direction opposite the arrow D' of ~IG. 1.
As seen in FIGS. 6-10 is a second embodiment of this inventive railroad car truc~ which is designated 200. Like the truck 10, the truck 200 includes a transversely posi-tioned bolster 202 having ends 204 resiliently carried in a window 206 formed in a left and right side frame 208, 210.
The side frames 208, 210 have a more conventional configuration in that the window 206 is defined by a bottom tension member 212 connecting with inclined members 214 to form a truss-like formation with a top compression member 216. The resilient support of the bolster 202 is provided by a set of springs 218 carried by each bottom tension member 212 of the left and right side frames 208, 210. This resilient support is further regulated by a snubbing device 1~460iZ
220. One preferred embodiment of such a snubbing device is disclosed in Canadian Patent No. 1,091,096.
At outer ends 222 of each side frame 208, 210 is a downward facing pedestal jaw 224. Each pedestal jaw 224 has a flat roof or top surface 226 and a pair of downwardly extend-ing spaced flanges 228 to define a covering area 230 having a rectangular configuration. Disposed in each covering area 230 is an elastomeric device 232. Like the truck 10, the truck 200 has four such devices 232.
Each elastomeric device 232 comprises an upper, middle and lower plate 234, 236, 238 integrally joined to an elastomeric material 240 which maintains the plates 234, 236, 238 in a spaced relationship. To facilitate forming this device into an integral unit, an aperture 242 is provided in each plate 234, 236, 238 to allow the elastomeric material 240 to be injection molded therebetween. Note that the upper plate 234 of each device 232 interfaces directly with the respective pedestal jaw covering area 230.
The lower plates 238 of the front elastomeric devices 232 are supported by a front steering arm 244 while the lower plates 232 of the rear elastomeric devices 232 are supported by a rear arm 246. The arms 244, 246 are substantially identical and therefore only the rear arm 246 will be descri-bed in detail. Note that arms 244, 246 are different from the arms 32, 42 of the first embodiment 10, however.
Each steering arm 244, 246 comprises an elongated middle part 251 having ends weldedly joined to a left and right side portions 252, 254. The side portions 252, 254 are identical except formed on an opposite hand. As shown in . Case 5705 11~60~
FIGS. 8, 9 and 10 is the right side portion 254 of the rear steering arm 246 which will be describéd in detail. The right side portion 254 has an offset configuration comprising an inwardly extending part 256, a longitudinal leg extension 258 and an outwardly extending part 260.
The inwardly extending part 256 has a C-shaped end wall 262 with chamfered edges 264 to facilitate joinder by welding to the elongated middle part 251 of the steering arm 246. Between the end wall 262 and the leg extension 258, the inwardly extending part 256 has an inverted L-shaped configuration which includes a top horizontal leg 266 with a vertical aperture 268 therethrough to provide access to one of four brake shoes 270 therebelow. The top leg 266 of the inwardly extending portion 256 and a vertical leg 272 of such join a front end of the longitudinal leg extension 258 to form inner and outer radius corners 274, 276.
The extension leg 258 has a thin hollow configuration which includes a top and a bottom wall 278, 280 which angles upwardly to join the outwardly extending part 260. Joining a rear end of inner and outer sidewalls 281, 282 of the leg extension 258 is a transversly positioned vertical partition 284 of the outwardly extending part 260. A top horizontal member 286 extends rearwardly from a top edge of the vertical partition 284. Along the outer top edges of the horizontal member 286 are upwardly projecting wedge-shaped flanges 288 which lie along a rectangular receiving area 290 for the elastomeric devices 232. As seen in FIG. 8, the outer end 222 of the right side frame 210 rests on the elastomeric device 232 and between the two flanges 288.
On a bottom side 292 of the horizontal member 286 is a circular-shaped recess 294 having an upwardly and inwardly Case 5705 11~601Z
converging circular sidewall 296. Disposed in the circular recess 294 is an annular boss 298 formed on the upper side 300 of a bearing adapter 302. The adapter annular boss 298 has an inwardly converging sidewall 304 to fit in a com-plementary manner with the sidewall 296 of the recess 294.
Each adapter 302 in turn fits over a bearing 306 in which axle ends 308 of a front and a rear wheelset 310, 312.
Because the bolster 202 transfers the load of the railroad car body thereabove (not shown) to the wheelsets 310, 312 through the side frames 208, 210, the elastomeric devices 232 to the steering arms 244, 246, the interaction between each adapter boss 298 and respective steering arm outwardly extending portion recess 294 forms a compressive joint 314.
These joints 314 become readily releaseable upon removal of the load. Additionally the joint 314 provides limited movement between the adapter 302 and each steering arm 244, 246 to provide a more perfect operational fit between such.
Under this arrangement, the wheelsets and respecti~e steering arms are formed into a unit.
To provide additional stiffness to the steering arm outwardly extending part 260, the vertical partition 284 extends below the bottom wall 280 of the leg extension 258 and is further joined to such by a horizontal web 316 which projects outwardly from the outer leg extension sidewall 282 and joins an outer sidewall 318 which also connects with the top horizontal member 286, the vertical partition 284 and an ; outer end of the horizontal web 316. The outer sidewall 318 has a downwardly curved shaped lower edge 320 whlch tangen-tially joins the vertical partition 284 at a point proximately aligned with the horizontal web 316 where it terminates.
Case 5705 The vertical partition 284 is further stiffened by a pair of spaced gussets 322 which are integrally joined to a bottom side 324 of the web 316 and to a tab 326 extending down-wardly from the vertical partition 384.
One preferred form of brake rigging for a steerable truck is disclosed in U.S. Patent No. 4,147,237. Another preferred brake rigging arangement, which is more conven-tional in nature and shown in FIG. 6, includes a front and rear brake beam 330, 332 which are each pivotally connected to a lower end of a front and rear brake lever 248, 249. A
tie rod 250 proximately aligned with a lonsitudinal axis of the railroad car connects the two brake levers 248, 249 in a middle portion of each. An opposite or upper end of one brake lever, for example the rear brake lever 249, may be pivotally connected to the truck bolster 202 or even the body of the railroad car. An oppo~ite or upper end of the other brake lever, i.e. the front brake lever 248, is then operatively connected to a source of power whereby the brake shoes 270 may be forced respectively against wheels 334 of each wheelset 310, 312.
Under this later brake rigging arrangement, upon activation, the front and rear wheelsets 306, 308 are forced apart in that the braking force is applied concurrently to the elastomeric devices 232. Under the braking arrangement - 25 described in U.S. Patent No. 4,147,237, the brake force does not act on the elastomeric devices 232 since the brake levers are carried directly by the steering arms 32, 42 of the truck 10 as is also shown in FIG. 1.
Like the first embodiment, i.e. truck 10, the front and rear steering arms 244, 246 of the truck 200 each carries a Case 5705 1~46~)1Z
.
bracket 336, 338 which extends from the middle portion 251 of each steering arm 244, 246. Each bracket 336, 33B
projects int~ a center cavity 340 of the bolster 202. One preferred embodiment of such a bolster center cavity 340 is disclosed in U.S. Patent No. 4,114,54Q wherein the center cavity 340 provides a clear passage through the bolster 202 so that the brackets 336, 338 remain independent of the bolster 202.
In the center cavity 340 the brackets 336, 338 are joined to form a movable joint 342 which may best be under-stood by viewing FIGS. 11-13. In an outer end of each bracket 336, 338 is an elongated aperture 344, 346. As shown by FIG. 11, when the brackets 336, 338 are positioned parallel, inner ends 348, 350 of each aperture 344, 346 aré
proximately aligned while outer ends 352, 354 are longitu-dinally offset. Surrounding each aperture 344, 346 on sides of each bracket 336, 338 is an elongated recess 356 which extends to an end of each bracket 336, 338. In each recess 358 is a set of spherical washers 358, 360, 362 and 364.
These spherical washer sets 358-364 are similar to the washer sets 166-172 and thus need not be described again.
Extending through the apertures 344, 346 and the washer sets 166-172 is a retention bolt 366 secured therein by a lock nut 368. About the bolt 366 and in between the washer sets 358, 360 and 362, 364 are bushings 370, 372 which interact between the bolt 366 and the apertures 344, 346 and maintain the bolt 366 in proper alignment, for example, when the steering arms 344, 346 swing to an out-of-square position as seen in FIG. 12.
Case 5705 ~46012 The truck 200 operates in substantially the same manner as truck 10. Because the wheels 334 have a conical-like profile, each wheelset 310, 312 attempts to center itself on the track on which -it is traveling. Since the distance between rails is not constant nor the rails straight, the wheelsets 310, 312 continuously move transversely or laterally to the direction of movement as denoted by the arrow D' in FIG. 6. Note that there is no independent lateral move-ment by either wheelset 310, 312 because of the joint 342 between the steering arms 244, 246. Some independent lateral movement may occur when the wheelsets 310, 312 swing to a nonaligned position. The joint 342 insures that such lateral movement of the wheelsets 306, 308 becomes joint after the independent movement exceeds certain nominal limits. 3y restricting independent lateral movement of the wheelsets 310, 312, improved wheel wear is obtained.
~ Additionally, as the truck 200 travels at a speed above a critical speed, each wheelset 306, 308 attempts to hunt or oscillate above its vertical axis. Note that when such hunting occurs, each wheelset 306, 308 attempts to move to an out-of-square position with respect to track over which the wheelsets 306, 308 are traveling. When these oscilla-tions of the wheelsets 306, 308 tend to be in-phase, the joint 342 through the steering arms 244, 246 inhibits such " 25 movement.
When the truck 200 is subjected to a braking force such that the brake shoes 270 carried by the more conventional brake rigging described earlier engages the wheels 334, the wheelsets 306, 308 are forced apart. As was noted, the brake levers 248, 249 need not be attached to the steering arms 244, 246 Case 5705 114ti012 as is suggested in U.S. Patent No. 4,147,237. This longi-tudinal displacement is accommodated by a deflector in the elastomeric devices 232 wherein the upper and lower plates 234, 236 of each device 232 are longitudinally offset.
Because each steering arm 244, 246 and its respective wheelsets 310, 312 are longitudinally fixed into a unit by the engagement between the adapter boss 298 with the recess 294 of the steering arm outwardly extending portion 260, each steering arm 244, 246 must also move longitudinally with its respective wheelset 310, 312. This longitudinal movement is accommodated by the joint 342 wherein the bolt 366 and the washer sets 358-364 move toward an outer end 352, 354 of each elongated aperture 344, 346 and recess 356 in the steering arm bracket 336, 338, respectively.
~uring this relative longitudinal movement between the bolt 366 and the front and rear steering arms 244, 246, the bushings 370, 372 insure that the bolt 366 remains properly aligned.
When the brake force on the shoes 270 is deactivated, the e}astomeric devices 232 return the wheelsets 310, 312 and respective steering arms 244, 246 to a normal position wherein the joint 312 appears as shown in ~IG. 11. Note that even during the application of the brake force des-cribed above, the joint 242 allows the wheelsets 310, 312 to swing to an out-of-square position if the truck 200 encounters a curved section of track. This swing action was discussed in detail with respect to truck 10 and the truck 200 is comparable in operation.
Case 5705 1~46()12 While various modifications may be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the pat~nt warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.
BACKGROUND OF THE INVENTION
Field of the Invention This invention relates .o a truck for use with railroad cars and particularly to a truck which allows relative yawing movement between a wheelset of the truck and side frames of the truck as the railroad car proceeds, for example, around a curve in a section of track on which the railroad car is traveling.
Prior Art Today most all railroad car trucks in use include spaced side frames resiliently supporting therebetween a transversely positioned bolster. The bolster contains a centerpla.e which in turn supports a body of the railroad car. The side frames have downward projecting jaws in which axle ends of a front and rear wheelset are rotatively journaled. Such trucks may be referred to as nonsteerable trucks.
Steerable trucks are ones having wheelsets which may yaw. Such trucks are well known and one typical type is disclosed in U.S. Patent No. 3,789,770. As disclosed, this truck allows rotation of each wheelset about its vertical axis so that the wheelset may take an out-of-square position with respect to a longitudinal axis of the truck. The wheelsets are joined by positive mechanical linkage which controls and maintains the relationship between the wheelsets.
Additionally, this linkage is connected to a body of the ~ Case 5705 ~146012 railroad car so that movement between the car body and the wheelsets is maintained in a fixed relationship.
Providing a flexible connection between the axle ends of the wheelset and the side frame to allow yawing there-between is also well known and is disclosed in, for example, U.S. Patent No. 3,785,298. In this case, a resilient or elastomeric device interfaces between pedestal jaws of a side frame of the truck and axle ends of the wheelsets to allow limited movement therebetween which is restrained by the elastomeric device.
U.S. Patent No. 3,528,374 discloses a truck which is perhaps the first to adapt the steering principle to a modern day truck. In this instance, a bolster has its ends resiliently carried by side frames. Ends of the side frames are adapted to allow the wheelsets of the truck to yaw. Yawing in turn is regulated by parallel elastic bracing members connecting aligned front and rear axle ends and diagonally positioned elastic bracing members connecting opposite front and rear axle ends.
A further arrangement to provide a truck with wheelsets which can yaw so as to maintain an aligned relationship with the track on which the truck is traveli~g is disclosed by U.5. Patent No. 4,003,316. As so disclosed, holding frames which carry the axle ends of t~e wheelsets are individually connected to a bolster of the truck through a ball bearing socket arrangement enclosed in a pad. Any lateral movement of the bolster effects a rotational movement of the holding frame and thus the wheelsets.
Most recent development in steerable trucks is perhaps disclosed in U.S. Patent Nos. 4,067,261 and 4,131,069. The - Case 5705 1~L4~0~Z
disclosure of the first patent places particular emphasis on the use of wheels having highly profiled wheel treads to generate steering forces. A pair of U-shaped subframes carries the axle ends of each wheelset and may be inter-connected by a pair of diagonally positioned rods. Theserods may be interconnected through a dampening means.
The 4,131,069 patent discloses a further steerable railroad car truck wherein resilient means of predetermined stiffness interconnects the axle ends carrying subframes of the truck at a centrally located point. Additionally, resilient means interconnect the s-~bframes with the side frames of the truck and the truck with a body of the car.
SUMMARY OF THE 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 supported by the pair of side frames at midpoints thereof are ends of a trans-versely positioned bolster which in turn support thereabove a body of a railroad car.
Within the front pedestal jaws of the side frames are side portions of a U-shaped front steering arm while a like rear steering arm has its side portions positioned within the rear jaws of the two side frames. Interfacing between a top surface of the side portions of each steering arm 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 in the side portions of each steering arm. The elastomeric devices allow the steering Case 5705 ~14601Z
arms and connected wheelsets to yaw or rotate about the vertical axis of the wheelset. When such rotation or yawing occurs, the wheelsets of the truck and steering arms move to an out-of-square position with respect to a longitudinal axis of the truck.
Protruding inwardly from a middle part of each steering arm is a bracket which is positioned parallel to the longi-tudinal axis of the truck and located within a center cavity specifically provided for such in the truck bolster. Inner ends of the brackets form part of a joint or connection with a plurality of spherical washers and a fastener. The joint provides a regulation of the wheelset movement to an out-of-square position which may proximate 1.8 degrees. During such movement to this out-of-square position, the joint remains independent of the bolster in that the center cavity provides a clear passage therethrough. Once in an out-of-square position, the joint provides only a negligible restoring force.
The truck of this invention has several important advantages over both nonsteerable trucks and steerable trucks presently known.
Firstly, the truck of this invention provides means allowing individual wheelsets to more perfectly react to curvature in the track on which the railroad car is traveling.
` 25 For example, when the truck encounters a left-hand curve in the track, the forwardmost or front wheelset will tend to rotate counterclockwise about its vertical axis while the rear wheelset will tend to likewise rotate counterclockwise about its vertical axis. This rotational tendency is created by the configuration o the outer surfaces of the wheels.
Case 5705 1146~)12 Nonsteerable trucks inhibit such rotation. Known steerable trucks allow such rotation which until now was controlled by some resilient device or by positive mechanical linkage connecting the ~ront and rear wheelsets.
In nonsteerable trucks, wear of the wheelsets is not minimized since a certain amount of slippage between the wheelset and the track is required to traverse a curve. In known steerable trucks controlled by resilient devices, increased yawing produces a likewise increased restoring force.
A further advantage of the truck of this invention is the recognition that to minimize wheelset wear, each wheelset must be allowed a certain amount of independent vertical movement with respect to each other wheelset to accommodaté
variations in the vertical height of the track. Such varia-tions occur, for example, between track elements particularly at joints therebetween where there has been rail wear adjacent the joint.
By providing for horizontal rotation of proximately 2 degrees, a certain amount of independent vertical movement, and selectively controlling these movements by the use of the elastomeric pads and the joint between the steering arms, wheelset wear is reduced and the truck provides improved stability by regulation of the various dynamic forces created during travel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of the truck of this invention with a partial section through one side frame of the truck.
FIG. 2 is an elevational view of the truck of FIG. 1.
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FIG. 3 is an offset elevational section view along line 3-3 of FIG. 1.
FIG. 4 is a cross-sectional view, which has been rotated 90 degrees, of a connecting joint formed between two steering arms as shown along the line 4-4 of FIG. 1.
FIG. 5 is a detailed sectional view of the side frame-steering arm-wheelset assembly shown in FIG. 3.
FIG. 6 is a plan view of a,further embodiment of the truck of this invention.
FIG. 7 is a side elevational view in partial section of the truck of FIG. 6 as seen generally along the line 7-7 of FIG. 6.
FIG. 8 is a partial cross-sectional view as seen generally along the line 8-8 of FIG. 7.
FIG. 9 is a side elevational view in detail of a side portion of a steering arm used in the truck of FIG. 6.
FIG. lG is a cross-sectional view as seen generally along the line 10-10 of FIG. 9.
FIG. 11 is a ¢ross-sectional view through a further embodiment of the joint between the steering arms.
FIG. 12 is the joint of FIG. 11 wherein the arms have rotated to a nonaligning position.
FIG. 13 is a cross-sectional view as seen generally along the line 13-13 of FIG. 11.
' DESCRIPTION OF THE PREFERRED EMBO~IMENT
A truck of this invention is shown generally at 10 and includes a front wheelset 12 and a rear wheelset 14. The front wheelset 12 has axle ends 16 journaled in front wheel bearings 18 while in a like manner the rear wheelset 14 has - Case 5705 1~4~0iZ
axle ends 20 journaled in rear wheel bearings 22. It should be understood that the truck 10 is nondirectional and "front" and "rear" are used to more conveniently describe the embodiment.
~o secure the position of the front wheelset 12, the front wheel bearings 18 are carried in a downward projecting semi-circular opening 24 formed in a left and a right side portion 28, 30 of a U-shaped front steering arm 32. In a like manner, the rear wheel bearings 22 associated with the rear wheelset 14 are carried in a like downward projecting semi-circular opening 34 formed in a left and a right side portion 38, 40 of a rear U-shaped steering arm 42. The rear steering arm 42 is positioned in an opposing manner with respect to the front steering arm 32 so that a middle part 44 of the front steering arm 32 is opposite a middle part 46 of the rear steering arm 42.
On a top surface 48 of each left and right side portion 28, 30 and 38, 40 of the front and rear steering arms 32 and 42 are upwardly projecting spaced flanges 50 positioned on each side of a rectangular recess 52 containing an elastomeric pad 54. The pad 54 has a rectangular configuration to form a snug fit within the recess 52. The recess 52 has a depth proximating 1/4 of a thickness of the pads 54 so that a top surface 56 of each pad 54 extends above the top surface 48 of the side portions 28 and 30 of the front steering arm 32 and of the side portions 38, 40 of the rear steering arm 42.
The truck 10 further includes a left and a right side frame 58, 60 formed having a front and rear downwardly projecting pedestal jaw 62 at each end of the side frames 58, 60.
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Each pedestal jaw 62 has a roof surface 70 with down-wardly projecting spaced flanges 72 defining in part a rectangular-shaped covering area 74 for the pads 54. Each area 74 has the same proximate size as each recess 52 of the front and rear steering arms 32 and 42. The height of the flanges 72 proximates 1/2 the thickness of the pad 54 so that a space 76 is formed between the flanges 72 of the pedestal jaws 62 and the top surface 48 of each side portion 28, 30.and 38, 40 when the left and right side frames 58 and 60 are assembled to and supported on the pads 54 respectively.
The front and rear steering arms 32, 42 each have a bracket 150 and 152 formed on a side 153 of each middle part 44 and 46 of the front and rear steering arms 32, 42 respec-tively, ~hese brackets 150 and 152 are opposing and offset from a center point of the respective arms 32, 42 so that apertures 154, 156 formed respectively in each bracket 150, 152 at its outer end are horizontally aligned as each bracket 150 and 152 extends into a center cavity 158 formed beneath .a centerplate 160 of a transversely positioned bolster 161.
The bolster 161 in turn has its ends resiliently carried by a set of springs 162 in a window 163 formed in each side frame 58, 60.
The front and rear brackets 150 and 152 form part of a joint 164 which further includes four sets of spherical washers 166, 168, 170 and 172. Each set of washers further comprises one element having a flat outer surface and an inner convex spherical surface which mates with a second element having an inner concave spherical surface and a flat outer surface. In the exemplary embodiment, the convex element has an "a" suffix while the concave element has a Case 5705 1~4601Z
"b" suffix so that, for example, the washer set 166 has a convex element 166a and a concave element 166b. A radius of curvature of the interfacing spherical surfaces of the washer sets 166-172 has been so selected to complement the rotational movement of the steering arms 32, 42.
About each aperture 154 and 156 on each side of the front and rear brackets 150, 152 are circular recesses 174, 176, 178 and 180 in which the washer sets 166, 168, 170 and 172 are respectively disposed. Note that each convex e~ement 166a, 168a, 170a and 172a is oriented toward the center of the joint 164. The connection 164 further includes a bolt 182 inserted through the washer sets 166-172 and the apertures 154 and 156 of the front and rear brackets 150, 152 and held therein by a self-locking nut 184. The bolt 182 and nut 184 are so assembled as to apply a slight compres-sive force to the various joint elements when each wheelset 12, 14 and each steering arm 32, 42 is in a squared relation-ship with respect to the longitudinal axis of the truck.
During travel of the truck 10 over a straight section of track, each wheelset 12, 14-tracks in a straight line path adjusting automatically for variations in track width and deviation from a straight line path. This automatic correction results from an interaction of the wheel tread with the track. Additionally, other deviations are regulated by a flexing of elastomeric pads 54 and the joint 164. This regulation also helps to control hunting of the wheelsets 12, 14 and lozenging of the side frames 58, 60.
During such straight line travel in a direction as shown by an arrow D in FIG. 1, some rolling of the wheelsets 12, 14, i.e. longitudinal rotation of the wheelsets about _g_ Case 5705 114~iVlZ
the longitudinal axis of the truck 10, occurs because of vertical difference in track height. As was noted earlier, such height differences particularly exist adjacent abutting track ends. This rolling movement of each wheelset is transferred to the front and rear steering arms 32, ~2 and regulated by the elastomeric pads 54 and the joint 164 where vertical movement between the spherical elements of the washer sets 166-172 may occur.
Upon first encountering a curved section of track, for example a left-hand curve, the front wheelset 12 of the truck 10 tracks about the curve and thus rotates or yaws counterclockwise about its vertical axis. This rotational movement is transferred to the front steering arm 32 causing a flexing of the front set of elastomeric pads 54 and horizontal movement between the spherical elements of the washer sets 166-172. ~ote that if the curved section is also banked to allow a higher speed of travel thereabout, there is likewise some rolling rotation of the front wheelset 12 and vertical movement between the spherical elements of the washer sets 166-172.
As the front wheelset 12 and the front steering arm 32 continue to rotate counterclockwise, this rotational move-ment is transferred by the front steering arm bracket 150 to the rear steering arm bracket 152 and thus may cause the rear steering arm 42 and rear wheelset 14 to rotate clockwise.
During this rotational movement of the front and the rear steering arm brackets 150, 152, the bolt 182 of the joint 164 moves in a straight line as noted by arrow D' as seen in FIG. 4.
This rotation of the steering arm brackets 150, 152 moves the washer set elements 166a,b-172a,b to a nonaligning Case 5705 ~14~V12 relationship such that the brackets 150, 152, through the washer sets 166-172, may apply some additional force on the bolt 182. This additional force on the bolt 182 helps to regulate the rotation of the steering arms 32, 42 and thus the front and rear wheelsets 12, 14. Note, however, that while the force on the bolt 182 regulates movement from a squared position to a nonsquared position, the bolt 182 only exerts a negligible restoring force.
As the truck 10 leaves the curved section of track to return to another straight section, the front wheelset 12 tracks clockwise causing the front steering arm 32 and the attached bracket 150 to likewise rotate clockwise. This clockwise rotation is transferred by the brackets 150, 152 and the washer sets 166-172 causing a counterclockwise rotation of the rear steering arm 42 and rear wheelset 14.
The joint 164 thus moves in a direction opposite the arrow D' of ~IG. 1.
As seen in FIGS. 6-10 is a second embodiment of this inventive railroad car truc~ which is designated 200. Like the truck 10, the truck 200 includes a transversely posi-tioned bolster 202 having ends 204 resiliently carried in a window 206 formed in a left and right side frame 208, 210.
The side frames 208, 210 have a more conventional configuration in that the window 206 is defined by a bottom tension member 212 connecting with inclined members 214 to form a truss-like formation with a top compression member 216. The resilient support of the bolster 202 is provided by a set of springs 218 carried by each bottom tension member 212 of the left and right side frames 208, 210. This resilient support is further regulated by a snubbing device 1~460iZ
220. One preferred embodiment of such a snubbing device is disclosed in Canadian Patent No. 1,091,096.
At outer ends 222 of each side frame 208, 210 is a downward facing pedestal jaw 224. Each pedestal jaw 224 has a flat roof or top surface 226 and a pair of downwardly extend-ing spaced flanges 228 to define a covering area 230 having a rectangular configuration. Disposed in each covering area 230 is an elastomeric device 232. Like the truck 10, the truck 200 has four such devices 232.
Each elastomeric device 232 comprises an upper, middle and lower plate 234, 236, 238 integrally joined to an elastomeric material 240 which maintains the plates 234, 236, 238 in a spaced relationship. To facilitate forming this device into an integral unit, an aperture 242 is provided in each plate 234, 236, 238 to allow the elastomeric material 240 to be injection molded therebetween. Note that the upper plate 234 of each device 232 interfaces directly with the respective pedestal jaw covering area 230.
The lower plates 238 of the front elastomeric devices 232 are supported by a front steering arm 244 while the lower plates 232 of the rear elastomeric devices 232 are supported by a rear arm 246. The arms 244, 246 are substantially identical and therefore only the rear arm 246 will be descri-bed in detail. Note that arms 244, 246 are different from the arms 32, 42 of the first embodiment 10, however.
Each steering arm 244, 246 comprises an elongated middle part 251 having ends weldedly joined to a left and right side portions 252, 254. The side portions 252, 254 are identical except formed on an opposite hand. As shown in . Case 5705 11~60~
FIGS. 8, 9 and 10 is the right side portion 254 of the rear steering arm 246 which will be describéd in detail. The right side portion 254 has an offset configuration comprising an inwardly extending part 256, a longitudinal leg extension 258 and an outwardly extending part 260.
The inwardly extending part 256 has a C-shaped end wall 262 with chamfered edges 264 to facilitate joinder by welding to the elongated middle part 251 of the steering arm 246. Between the end wall 262 and the leg extension 258, the inwardly extending part 256 has an inverted L-shaped configuration which includes a top horizontal leg 266 with a vertical aperture 268 therethrough to provide access to one of four brake shoes 270 therebelow. The top leg 266 of the inwardly extending portion 256 and a vertical leg 272 of such join a front end of the longitudinal leg extension 258 to form inner and outer radius corners 274, 276.
The extension leg 258 has a thin hollow configuration which includes a top and a bottom wall 278, 280 which angles upwardly to join the outwardly extending part 260. Joining a rear end of inner and outer sidewalls 281, 282 of the leg extension 258 is a transversly positioned vertical partition 284 of the outwardly extending part 260. A top horizontal member 286 extends rearwardly from a top edge of the vertical partition 284. Along the outer top edges of the horizontal member 286 are upwardly projecting wedge-shaped flanges 288 which lie along a rectangular receiving area 290 for the elastomeric devices 232. As seen in FIG. 8, the outer end 222 of the right side frame 210 rests on the elastomeric device 232 and between the two flanges 288.
On a bottom side 292 of the horizontal member 286 is a circular-shaped recess 294 having an upwardly and inwardly Case 5705 11~601Z
converging circular sidewall 296. Disposed in the circular recess 294 is an annular boss 298 formed on the upper side 300 of a bearing adapter 302. The adapter annular boss 298 has an inwardly converging sidewall 304 to fit in a com-plementary manner with the sidewall 296 of the recess 294.
Each adapter 302 in turn fits over a bearing 306 in which axle ends 308 of a front and a rear wheelset 310, 312.
Because the bolster 202 transfers the load of the railroad car body thereabove (not shown) to the wheelsets 310, 312 through the side frames 208, 210, the elastomeric devices 232 to the steering arms 244, 246, the interaction between each adapter boss 298 and respective steering arm outwardly extending portion recess 294 forms a compressive joint 314.
These joints 314 become readily releaseable upon removal of the load. Additionally the joint 314 provides limited movement between the adapter 302 and each steering arm 244, 246 to provide a more perfect operational fit between such.
Under this arrangement, the wheelsets and respecti~e steering arms are formed into a unit.
To provide additional stiffness to the steering arm outwardly extending part 260, the vertical partition 284 extends below the bottom wall 280 of the leg extension 258 and is further joined to such by a horizontal web 316 which projects outwardly from the outer leg extension sidewall 282 and joins an outer sidewall 318 which also connects with the top horizontal member 286, the vertical partition 284 and an ; outer end of the horizontal web 316. The outer sidewall 318 has a downwardly curved shaped lower edge 320 whlch tangen-tially joins the vertical partition 284 at a point proximately aligned with the horizontal web 316 where it terminates.
Case 5705 The vertical partition 284 is further stiffened by a pair of spaced gussets 322 which are integrally joined to a bottom side 324 of the web 316 and to a tab 326 extending down-wardly from the vertical partition 384.
One preferred form of brake rigging for a steerable truck is disclosed in U.S. Patent No. 4,147,237. Another preferred brake rigging arangement, which is more conven-tional in nature and shown in FIG. 6, includes a front and rear brake beam 330, 332 which are each pivotally connected to a lower end of a front and rear brake lever 248, 249. A
tie rod 250 proximately aligned with a lonsitudinal axis of the railroad car connects the two brake levers 248, 249 in a middle portion of each. An opposite or upper end of one brake lever, for example the rear brake lever 249, may be pivotally connected to the truck bolster 202 or even the body of the railroad car. An oppo~ite or upper end of the other brake lever, i.e. the front brake lever 248, is then operatively connected to a source of power whereby the brake shoes 270 may be forced respectively against wheels 334 of each wheelset 310, 312.
Under this later brake rigging arrangement, upon activation, the front and rear wheelsets 306, 308 are forced apart in that the braking force is applied concurrently to the elastomeric devices 232. Under the braking arrangement - 25 described in U.S. Patent No. 4,147,237, the brake force does not act on the elastomeric devices 232 since the brake levers are carried directly by the steering arms 32, 42 of the truck 10 as is also shown in FIG. 1.
Like the first embodiment, i.e. truck 10, the front and rear steering arms 244, 246 of the truck 200 each carries a Case 5705 1~46~)1Z
.
bracket 336, 338 which extends from the middle portion 251 of each steering arm 244, 246. Each bracket 336, 33B
projects int~ a center cavity 340 of the bolster 202. One preferred embodiment of such a bolster center cavity 340 is disclosed in U.S. Patent No. 4,114,54Q wherein the center cavity 340 provides a clear passage through the bolster 202 so that the brackets 336, 338 remain independent of the bolster 202.
In the center cavity 340 the brackets 336, 338 are joined to form a movable joint 342 which may best be under-stood by viewing FIGS. 11-13. In an outer end of each bracket 336, 338 is an elongated aperture 344, 346. As shown by FIG. 11, when the brackets 336, 338 are positioned parallel, inner ends 348, 350 of each aperture 344, 346 aré
proximately aligned while outer ends 352, 354 are longitu-dinally offset. Surrounding each aperture 344, 346 on sides of each bracket 336, 338 is an elongated recess 356 which extends to an end of each bracket 336, 338. In each recess 358 is a set of spherical washers 358, 360, 362 and 364.
These spherical washer sets 358-364 are similar to the washer sets 166-172 and thus need not be described again.
Extending through the apertures 344, 346 and the washer sets 166-172 is a retention bolt 366 secured therein by a lock nut 368. About the bolt 366 and in between the washer sets 358, 360 and 362, 364 are bushings 370, 372 which interact between the bolt 366 and the apertures 344, 346 and maintain the bolt 366 in proper alignment, for example, when the steering arms 344, 346 swing to an out-of-square position as seen in FIG. 12.
Case 5705 ~46012 The truck 200 operates in substantially the same manner as truck 10. Because the wheels 334 have a conical-like profile, each wheelset 310, 312 attempts to center itself on the track on which -it is traveling. Since the distance between rails is not constant nor the rails straight, the wheelsets 310, 312 continuously move transversely or laterally to the direction of movement as denoted by the arrow D' in FIG. 6. Note that there is no independent lateral move-ment by either wheelset 310, 312 because of the joint 342 between the steering arms 244, 246. Some independent lateral movement may occur when the wheelsets 310, 312 swing to a nonaligned position. The joint 342 insures that such lateral movement of the wheelsets 306, 308 becomes joint after the independent movement exceeds certain nominal limits. 3y restricting independent lateral movement of the wheelsets 310, 312, improved wheel wear is obtained.
~ Additionally, as the truck 200 travels at a speed above a critical speed, each wheelset 306, 308 attempts to hunt or oscillate above its vertical axis. Note that when such hunting occurs, each wheelset 306, 308 attempts to move to an out-of-square position with respect to track over which the wheelsets 306, 308 are traveling. When these oscilla-tions of the wheelsets 306, 308 tend to be in-phase, the joint 342 through the steering arms 244, 246 inhibits such " 25 movement.
When the truck 200 is subjected to a braking force such that the brake shoes 270 carried by the more conventional brake rigging described earlier engages the wheels 334, the wheelsets 306, 308 are forced apart. As was noted, the brake levers 248, 249 need not be attached to the steering arms 244, 246 Case 5705 114ti012 as is suggested in U.S. Patent No. 4,147,237. This longi-tudinal displacement is accommodated by a deflector in the elastomeric devices 232 wherein the upper and lower plates 234, 236 of each device 232 are longitudinally offset.
Because each steering arm 244, 246 and its respective wheelsets 310, 312 are longitudinally fixed into a unit by the engagement between the adapter boss 298 with the recess 294 of the steering arm outwardly extending portion 260, each steering arm 244, 246 must also move longitudinally with its respective wheelset 310, 312. This longitudinal movement is accommodated by the joint 342 wherein the bolt 366 and the washer sets 358-364 move toward an outer end 352, 354 of each elongated aperture 344, 346 and recess 356 in the steering arm bracket 336, 338, respectively.
~uring this relative longitudinal movement between the bolt 366 and the front and rear steering arms 244, 246, the bushings 370, 372 insure that the bolt 366 remains properly aligned.
When the brake force on the shoes 270 is deactivated, the e}astomeric devices 232 return the wheelsets 310, 312 and respective steering arms 244, 246 to a normal position wherein the joint 312 appears as shown in ~IG. 11. Note that even during the application of the brake force des-cribed above, the joint 242 allows the wheelsets 310, 312 to swing to an out-of-square position if the truck 200 encounters a curved section of track. This swing action was discussed in detail with respect to truck 10 and the truck 200 is comparable in operation.
Case 5705 1~46()12 While various modifications may be suggested by those versed in the art, it should be understood that I wish to embody within the scope of the pat~nt warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.
Claims (8)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A truck for use with a railroad car comprising, a right and left spaced side frame with each said side frame having a front and rear downwardly projecting pedestal jaw, an elongated bolster with a center cavity providing a clear passage therethrough, said bolster positioned trans-versely to said side frame and having ends supported thereby, elastomeric pads positioned one each in said pedestal jaws and having a top surface interfacing with a roof of said jaw respectively, a front and rear steering arm having side portions interfacing with a bottom surface of said elastomeric pads respectively, a front and rear wheelset having axle ends journaled in bearings carried in said side portions of said front and rear steering arms with said bearings of said side portions aligning vertically with said side frame pedestal jaws, a front and rear bracket carried by a middle part of said front and rear steering arms respectively, each said bracket having an aperture formed at an outer end thereof, said brackets projecting from each side of said bolster into said bolster center cavity in a manner to be independent of said bolster with said apertures of said brackets being substantially aligned therein, and means forming a joint between said front and rear steering arm brackets, said means including washer sets interfacing between said brackets and on outside surfaces of each said bracket, and a fastening device disposed in said Case 5705 bracket apertures and through said washer sets to provide a selective engagement therebetween, wherein said front and rear wheelsets and respec-tive steering arms may rotate between a squared position and an out-of-square position, said rotation selectively restrained by said pads and said joint means.
2. A railroad car truck particularly adapted for maintaining dynamic lateral stability at reasonable operating speeds and permitting appropriate wheelset alignment of said truck during curve negotiation, said truck comprising, a right and left side frame spaced to support ends of an elongated bolster positioned transversely between said side frames, each said side frame having a downwardly projecting pedestal jaw formed at ends of said frame with each said jaw having a roof surface with a recessed pad covering area formed therein, a front and a rear steering arm each having spaced side portions joined by a middle part, each said side portion formed having a downwardly projecting bearing receiving area and a top surface having an upwardly facing recessed pad receiving area, said front arm positioned between said side frames with said side portions carried in said front pedestal jaws and separated therefrom by an elastomeric pad disposed in said front pad receiving and covering areas respectively to form a space between said side frame and said steering arm, and said rear arm positioned between said side frames with said middle part opposing and adjacent to said front Case 5705 arm middle part and with said side portions carried in said rear pedestal jaws and separated therefrom by an elastomeric pad disposed in said rear pad receiving and covering areas respectively to form a space between said side frames and said rear steering arm, a front and rear wheelset, said wheelsets having axle ends journaled in bearings carried in said bearing receiving areas of said front and rear arms respectively, a front and a rear bracket carried by said middle part of said front and said rear steering arms respectively, said brackets projecting into a bolster center cavity in a manner to be independent of said bolster, said brackets positioned to lie on each side of said longitudinal axis of said truck and having substantially aligned apertures formed in an outer end of each said bracket, and washer sets having elements with inner contacting complementary spherical-like surfaces, said sets positioned between said brackets and on outer sides of said brackets and held therewith by a fastening device extending through said washer sets and said bracket apertures to form a joint, wherein each wheelset may rotate as a function of a configuration of said track with said rotation selectively inhibited by said elastomeric pads and said joint formed between said steering arm brackets and said washer sets.
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Case 5705
3. A truck as defined by Claim 2 and further char-acterized by, said steering arm brackets having a circular inner and outer recess formed about said apertures respectively, said washer sets comprising a first, second, third and fourth set with each said set including a convex element having a flat outer surface and a spherically convex inner surface, and a concave element having a flat outer surface and a spherically concave inner surface mated with said convex inner surface of said convex element, said first washer set disposed in said outer recess of said front bracket with said flat outer surface of said concave element in contact with said front bracket, said second washer set disposed in said inner recess of said front bracket with said flat outer surface of said convex element in contact with said front bracket, said third washer set disposed in said inner recess of said rear bracket with said flat outer surface of said convex element in contact with said rear bracket, and said fourth washer set disposed in said outer recess of said rear bracket with said flat outer surface of said concave element in contact with said rear bracket.
4. In a railroad car truck particularly adapted to provide improved wheel and rail wear under heavy-load high-speed operation and over curved trackage, said truck having a left and a right side frame in a spaced relationship and an elongated bolster transversely positioned between said side frames, said bolster having ends resiliently carried in a window formed in said side frames respectively, the improvement therein comprising, Case 5705 a first and a second wheelset each having axle ends journaled in bearings, a first and a second steering arm positioned one each on each side of said bolster, each said steering arm having side portions operatively connected to said wheelsets through said bearings respectively, each said steering arm and respective wheelset forming a front and rear unit with wheelset movements being selectively transmitted to said steering arms respectively to provide concurrent movement between such, elastomeric means joining said steering arm side portions to said side frames to allow each said unit to move independently of said side frames, bracket means carried by a middle portion of each said steering arm, each said bracket projecting into a clear passage formed in a middle of said bolster in a manner to be independent thereof, said brackets being transversely offset to provide substantial alignment for apertures formed in an outer end of each said bracket, and means positioned through and above said bracket apertures to join said first and second wheelset-steering arm units and allow limited independent movement of such units and promote joint movement of said units upon said movement exceeding set limits, wherein said wheelset-steering arm units may selectively yaw and roll to move to an aligned position with track on which said truck may be traveling, said aligned portion of said wheelsets being maintained by said elasto-meric means and said means joining said units.
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5. A railroad car truck as defined by Claim 4 and further characterized by said means joining said first and second wheelset-steering arm units comprising, a recess formed about said aperture on each side of each said bracket, a spherical washer set including a first element having a flat outer surface and convex inner surface and a second element having a flat outer surface and a concave inner surface complementarily formed to receive said convex inner surface of said first element in a slideable relation-ship, one each of said washer sets being selectively posi-tioned in said bracket recesses, and a fastening device extending through said washer sets and said bracket apertures to secure such in position but allow selective relative movement between said fastening device, said brackets, said washer sets and said washer set elements.
6. A railroad car truck as defined by Claim 5 and further characterized by comprising, brake rigging including a brake shoe to engage one each of wheels of said wheelsets, said brake rigging being carried by said truck independent of said wheelset-steering arm units to apply a longitudinally separating force to said units upon energizing said rigging whereby said elastomeric means being longitudinally offset, said steering arm bracket apertures being elongated with inner ends of each said elongated aperture being proxi-mately aligned upon said brake rigging being de-energized, Case 5705 bushing means disposed about said fastening device in each steering arm bracket aperture to interface between said aperture and said fastening device, and said steering arm bracket recesses being elongated to accommodate movement of said respective washer set in said recess, wherein upon energizing of said brake rigging, said brake shoes engage said wheels forcing said first and second wheelset-steering arm units longitudinally apart to cause said elastomeric devices to flex longitudinally with said fastening device moving toward an outer end of each elongated bracket aperture and said bushings maintaining said fastening device in proper alignment within said apertures.
7. A railroad car truck as defined in Claim 4 and further characterized by comprising, adapter means disposed one each over said axle end bearings, each said adapter having an annular boss formed on an upper side of such, and each said side portion of said first and said second steering arms having an outwardly extending part defined in part by a horizontal member, said member having a circular recess formed in a bottom surface of such with said adapter boss received therein to form a natural fitting joint under a compressive force, said joint being readily releasable upon removal of said compressive force.
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Case 5705
8. A railroad car truck as defined by Claim 7 and further characterized by each said steering arm side portion having an offset configuration and further including, an inwardly extending part having an end wall prepared to be readily connected to said steering arm middle portion, said end wall joined by an upper horizontal leg and a vertical leg with an aperture formed in said horizontal leg to provide access to brake rigging means carried by said truck therebelow, a longitudinal leg extension part positioned parallel and inside said side frame adjacent thereto, said leg extension part comprising a top and a bottom wall joined by spaced inner and outer sidewalls, one end of said leg extension joined to said legs of said inwardly extending part and an opposite end joined to said outwardly extending part at a point above said inwardly extending part, said outwardly extending part further comprising a vertical partition carried across said opposite ends of said leg extension top wall, bottom wall and inner and outer sidewall, said vertical partition having a top edge joined to said top member, a horizontal web connecting said leg extension outer sidewall and said vertical partition, and a pair of spaced gussets connected to a bottom of said web and to a tab formed on a bottom of said vertical partition.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US5393479A | 1979-07-02 | 1979-07-02 | |
| US53,934 | 1979-07-02 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1146012A true CA1146012A (en) | 1983-05-10 |
Family
ID=21987557
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000354901A Expired CA1146012A (en) | 1979-07-02 | 1980-06-26 | Truck for railroad cars |
Country Status (11)
| Country | Link |
|---|---|
| JP (1) | JPS582092B2 (en) |
| AR (1) | AR225046A1 (en) |
| AU (1) | AU6002680A (en) |
| BE (1) | BE884116A (en) |
| BR (1) | BR8004089A (en) |
| CA (1) | CA1146012A (en) |
| ES (1) | ES492969A0 (en) |
| GB (1) | GB2055339A (en) |
| PT (1) | PT71403A (en) |
| SE (1) | SE8003597L (en) |
| ZA (1) | ZA803325B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8324867D0 (en) * | 1983-09-16 | 1983-10-19 | Becorit Ltd | Rail vehicles and bogie |
-
1980
- 1980-05-13 SE SE8003597A patent/SE8003597L/en unknown
- 1980-06-02 AR AR281619A patent/AR225046A1/en active
- 1980-06-04 ZA ZA00803325A patent/ZA803325B/en unknown
- 1980-06-17 PT PT71403A patent/PT71403A/en unknown
- 1980-06-23 GB GB8020513A patent/GB2055339A/en not_active Withdrawn
- 1980-06-26 CA CA000354901A patent/CA1146012A/en not_active Expired
- 1980-06-27 JP JP55086746A patent/JPS582092B2/en not_active Expired
- 1980-06-30 BR BR8004089A patent/BR8004089A/en unknown
- 1980-07-01 ES ES492969A patent/ES492969A0/en active Granted
- 1980-07-01 BE BE0/201267A patent/BE884116A/en unknown
- 1980-07-02 AU AU60026/80A patent/AU6002680A/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| ES8102026A1 (en) | 1980-12-16 |
| JPS5617755A (en) | 1981-02-19 |
| AU6002680A (en) | 1981-01-15 |
| BR8004089A (en) | 1981-01-21 |
| SE8003597L (en) | 1981-01-03 |
| GB2055339A (en) | 1981-03-04 |
| PT71403A (en) | 1980-07-01 |
| JPS582092B2 (en) | 1983-01-14 |
| BE884116A (en) | 1981-01-05 |
| ES492969A0 (en) | 1980-12-16 |
| AR225046A1 (en) | 1982-02-15 |
| ZA803325B (en) | 1981-05-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |