GB2055339A - Railroad car truck - Google Patents

Abstract

The truck 200 has a front and a rear wheelset 310,312 with axle ends rotatively carried in a front and rear steering arm 244, 246 respectively. The steering arms 244, 246 are carried in pedestal jaws 224 of a right and left side frame 208, 210 with resilient pads 232 interfacing between the steering arms 244, 246 and the side frames 208, 210. The resilient pads 232 allow each wheelset 310, 312 and steering arm 244, 246 to rotate or yaw to an out-of-square condition with respect to the side frames 208, 210 as the railroad car proceeds, for example, around a curve in the track on which the car is travelling. This rotational movement is selectively regulated by a joint 342 connecting the front and rear steering arms 244, 246 so as to permit relative independent movement of the steering arms 244, 246 up to a predetermined limit after which the arms move together. The joint 342 may also allow relative movement of the steering arms 244, 246 in the longitudinal direction of the truck 200. <IMAGE>

Description

SPECIFICATION Railroad car truck This invention relates to a truck for use with railroad cars and particularly to a truck which will allow 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 travelling.

Many railroad car trucks in use include spaced side frames which resiliently support therebetween a transversely positioned bolster. The bolster contains a centreplate 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 rotatably 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 Specification No. 3,789,770. As disclosed, this truck allows rotation of each wheelset about a 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 a relationship between the wheelsets. Additionally, this linkage is connected to a body of the 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 therebetween is also well known and is disclosed in, for example, U.S.

Patent Specification 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 Specification 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 end 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 travelling is disclosed by U.S. Patent Specification 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 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 Specification Nos. 4,067,261 and 4,131,069. The 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 interconnected by a pair of diagonally positioned rods. These rods may be interconnected through a dampening means.

The 4,131,069 specification 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 subframes with the side frames of the truck and the truck with a body of the car.

One example of 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 transversely positioned bolster which in turn can 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 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-ofsquare 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 longitudinal axis of the truck and located within a centre cavity in the truck bolster. Inner ends of the brackets form part of a joint or connection with a joining means which comprises 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 centre cavity provides a clear passage therethrough. Once in an out-of-square position, the joint provides only a negligible restoring force.

An aim of the present invention is to provide several important advantages over both nonsteerable trucks and steerable trucks presently known.

One such aim is to provide means allowing individual wheelsets to more perfectly react to curvature in the track on which the railroad car is travelling. 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 also tend to rotate its vertical axis. This rotational tendency is created by the configuration of the outer surfaces of the wheels. 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 front 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 accommodate variations in the vertical height of the tFa < ck. Such variations occur, for example, betweeimtrack 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.

A further aim of this invention is to allow relative movement of the steering arms, and hence wheelsets in the longitudinal direction of the track, for example, under braking conditions.

The present invention will be further described by way of example with reference to the accompanying drawings, in which: Figure 1 is a plan view of a truck according to this invention with a partial section through one side frame of the truck.

Figure 2 is an elevational view of the truck of Fig. 1.

Figure 3 is an offset elevational section view along line 3-3- of Fig. 1.

Figure 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.

Figure 5 is a detailed sectional view of the side frame-steering arm-wheelset assembly shown in Fig. 3.

Figure 6 is a plan view of a further embodiment of the truck of this invention.

Figure 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.

Figure 8 is a partial cross-sectional view as seen generally along the line 8-8 of Fig. 7.

Figure 9 is a side elevational view in detail of a side portion of a steering arm used in the truck of Fig. 6.

Figure 10 is a cross-sectional view as seen generally along the line 10-10 of Fig. 9.

Figure ii is a cross-sectional view through a further embodiment of the joint between the steering arms.

Figure 12 is the joint of Fig. 11 wherein the arms have rotated to a nonaligning position.

Figure 13 is a cross-sectional view as seen generally along the line 13-13 of Fig. 11.

A truck of this invention is shown generally at 10 and includes a front wheelset 1 2 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 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.

To 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.

Each pedestal jaw 62 has a roof surface 70 with downwardly 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 1 50 and 1 52 formed on a side 1 53 of each middle part 44 and 46 of the front and rear steering arms 32, 42 respectively. These brackets 1 50 and 1 52 are opposing and offset from a centre point of the respective arms 32, 42 so that apertures 154, 1 56 formed respectively in each bracket 150, 1 52 at its outer end are horizontally aligned as each bracket 1 50 and 1 52 extends into a centre cavity 1 58 formed beneath a centreplate 1 60 of a transversely positioned bolster 161.The bolster 161 in turn has its ends resiliently carried by a set of springs 1 62 in a window 1 63 formed in each side frame 58, 60.

The front and rear brackets 1 50 and 1 52 form part of a joint 1 64 which further includes four sets of spherical washers 166, 168, 1 70 and 1 72. 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 "b" suffix so that, for example, the washer set 1 66 has a convex element 1 66a 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 1 54 and 1 56 on each side of the front and rear brackets 150, 1 52 are circular recesses 174, 176, 1 78 and 180 in which the washer sets 166, 1 68, 1 70 and 1 72 are respectively disposed. Note that each convex element 166a, 168a, 1 70a and 1 72a is oriented toward the centre of the joint 1 64.

The connection 1 64 further includes a bolt 1 82 inserted through the washer sets 166-172 and the aperture 154 and 156 of the front and rear brackets 150, 1 52 and held therein by a self-locking nut 1 84. The bolt 1 82 and nut 184 are so assembled as to apply a slight compressive force to the various joint elements when each wheelset 12, 14 and each steering arm 32, 42 is in a squared relationship 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 1 64. 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. rotation of the wheelsets about 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, 42 and regulated by the elastomeric pads 54 and the joint 1 64 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 1 2 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 166-1 72. Note 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 1 2 and vertical movement between the spherical elements of the washer sets 166-172.

As the front wheelset 1 2 and the front steering arm 32 continue to rotate counterclockwise, this rotational movement is transferred by the front steering arm bracket 1 50 to the rear steering arm bracket 1 52 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 1 82 of the joint 1 64 moves in a straight line as noted by arrow D' as seen in Fig. 4.

This rotation of the steering arm brackets 150, 1 52 moves the washer set elements 166a,b-172a,b to a nonaligning relationship such that the brackets 150, 152, through the washer sets 166-172, may apply some additional force on the bolt 1 82. This additional force on the bolt 1 82 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 1 82 regulates movement from a squared position to a nonsquared position, the bolt 1 82 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 1 2 tracks clockwise causing the front steering arm 32 and the attached bracket 1 50 to likewise rotate clockwise. This clockwise rotation is transferred by the brackets 150, 1 52 and the washer sets 166-172 causing a counterclockwise rotation of the rear steering arm 42 and rear wheelset 14. The joint 1 64 thus moves in a direction opposite the arrow D' of Fig. 1.

Figs. 6-10 illustrate a second embodiment of this inventive railroad car truck which is designated 200. Like the truck 10, the truck 200 includes a transversely positioned 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 21 6. The resilient support of the bolster 202 is provided by a set of springs 21 8 carried by each bottom tension member 21 2 of the left and right side frames 208, 210. This resilient support is further regulated by a snubbing device 220. One preferred embodiment of such a snubbing device is disclosed in United States Patent Specification No. 844,965 filed October 17, 1977.

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 extending 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 moulded 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 described 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 elongate middle part 251 having ends joined by welding to a left and right side portion 252, 254. The side portions 252, 254 are mirror images. As shown in Figs. 8, 9 and 10 is the right side portion 254 of the rear steering arm 246 which will be described 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 Cshaped end wall 262 with chamfered edges 264 to facilitate joining by welding to the elongate 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 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 transversely 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 wedgeshaped 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 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 complementary manner with the sidewall 296 of the recess 294.

Each adapter 302 in turn fits over a bearing 306 in which are journaled axle ends 308 of a front and a rear wheelset 310, 31 2. Because the bolster 202 transfers the load of the railroad car body thereabove (now shown) to the wheelsets 310, 31 2 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 releasable 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 respective 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 31 8 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 which tangentially joins the vertical partition 284 at a point proximately aligned with the horizontal web 31 6 where it terminates.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 downwardly from the vertical partition 384.

One preferred form of brake rigging for a steerable truck is disclosed in U.S. Patent Specification No. 4,147,237. Another preferred brake rigging arrangement, which is more conventional 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 longitudinal 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 opposite or upper end of the other brake lever, e.g. 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 are forced apart in that the braking force is applied concurrently to the elastomeric devices 232. Under the braking arrangement described in U.S. Patent Specification 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 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 carried a bracket 336, 338 which extends from the middle portion 251 of each steering arm 244, 246. Each bracket 336, 338 projects into a centre cavity 340 of the bolster 202. One preferred embodiment of such a bolster centre cavity 340 is disclosed in U.S. Patent Specification No. 4,114,540 wherein the centre cavity 340 provides a clear passage through the bolster 202 so that the brackets 336, 338 remain independent of the bolster 202.

In the centre cavity 340 the brackets 336, 338 are joined to form a movable joint 342 which may best be understood by viewing Figs. 11-13. In an outer end of each bracket 336, 338 is an aperture 344, 346 which apertures are alongate in the longitudinal direction of the truck. As shown by Fig. 11, when the brackets 336, 338 are positioned parallel, inner ends 348, 350 of each aperture 344, 346 are proximately axially aligned while outer ends 352, 354 are offset in the longitudinal direction. Surrounding each aperture 344, 346 on sides of each bracket 336, 338 is an elongate 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 locking 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.

The truck 200 operates in substantially the same manner as truck 10. Because the wheels 334 have a conical-like profile, each wheelset 310, 31 2 attempts to centre itself on the track on which it is travelling. 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 movement by eight wheelset 310, 31 2 because of the joint 342 between the steering arms 244, 246. Some independent lateral movement may occur when the wheelsets 310, 31 2 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. By restricting independent lateral movement of the wheelsets 310, 31 2 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 about 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 travelling. When these oscillations of the wheelsets 306, 308 tend to be in-phase, the joint 342 through the steering arms 244, 246 inhibits such 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 as is suggested in U.S. Patent Specification No. 4,147,237. This longitudinal 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, 31 2 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 elongate aperture 344, 346 and recess 356 in the steering arm bracket 336,338 respectively.

During this relative longitudinal movement between the bolt 366 and the front and rear steering arms 244, 246, the bushings 370, 372 ensure that the bolt 366 remains properly aligned.

When the brake force on the shoes 270 is deactivated the elastomeric devices 232 return the wheelsets 310, 31 2 and respective steering arms 244,246 to a normal position wherein the joint 342 appears as shown in Fig. 11. Note that even during the application of the brake force described above the joint 242 allows the wheelsets 310, 31 2 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.

While various modifications may be suggested by those versed in the art, it should be understood that the present invention embodies such modifications as reasonably and properly come within the scope of the accom

Claims (11)

panying claims. CLAIMS

1. A railroad car truck having a left and a right side frame in a spaced relationship and an elongate bolster transversely positioned between said side frames, said bolster having ends each resiliently carried in a window provided in a respective side frame, a first and a second wheelset each having axle ends journalled in bearings, a first and a second steering arm positioned one each on opposite sides of said bolster, each said steering arm having side portions operably connected to said wheelsets by means of said bearings respectively, said steering arms and respective wheelsets forming a first and a second unit respectively with wheelset movements being selectively transmitted to said steering arms respectively to provide concurrent movement between such, said steering arm side portions joined to said side frames by elastomeric means thereby to allow each said unit to move relative to 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, each of said brackets being transversely offset from the other and having an aperture formed in an outer end, joining means engaging with said brackets by means of said apertures thereby to join said first and second wheelset-steering arm units and allow predetermined limited independent movement of such units and promote joint movement of said units upon said movement exceeding said predetermined limit, wherein in use said wheelset-steering arm units can selectively yaw and roll to move to an aligned position with track on which said truck is travelling, said aligned position of said wheelsets being maintained by said elastomeric means and said joining means.

2. A railroad car truck as defined by Claim 1, wherein a recess is provided on each side of each said bracket about. each said aperture and said joining means comprises 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 relationship, one each of said washer sets being selectively positioned 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.

3. A railroad car truck as defined by Claim 2 and further characterised by comprising brake rigging including brake shoes to engage one each of wheels of said wheelsets, said brake rigging being carried by said truck independent of said wheelset-steering arm units such as to apply a longitudinally separating force to said units upon operation of said rigging and whereby said elastomeric means is longitudinally offset, said steering arm bracket apertures are alongate in the longitudinal direction of said truck with inner ends of each said elongate aperture being proximately axially aligned with said fastening device when said brake rigging is not in operation, 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 elongate to accommodate movement of said respective washer set in said recess, wherein in use upon operation 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 elongate bracket aperture and said bushings maintaining said fastening device in alignment within said apertures.

4. A railroad car truck as defined in Claim 1, 2 or 3, further characterized iby comprising, adapter means disposed one each over said axle end bearings, each said adapter having an annular boss formed on an upper side thereof, 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 thereof, said adapter boss being received therein to form a fitting joint under a compressive force, said joint being readily releasable upon removal of said compressive force.

5. A railroad car truck as defined by any of Claims 1 to 4, further characterized by each said steering arm side portion having an offset configuration and further including, an inwardly extending part having an end wall readily connectable 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 when carried by said truck, 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 exending 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.

6. 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 elongate bolster with a centre cavity providing a clear passage therethrough, said bolster positioned transversely 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 a said elastomeric pad respectively, a front and rear wheelset having axle ends journalled in bearings carried in said side portions of said front and rear steering arms, said bearings of said side portions vertically aligning with said side frame pedestal jaws, a front and rear bracket carried by a middle part of a 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 centre 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 bracket apertures and through said washer sets to provide a selective engagement therebetween, wherein said front and rear wheelsets and respective steering arms may rotate between a squared position and an outof-square position, said rotation selectively restrained by said pads and said joint means.

7. 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 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 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 wheelsst, 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 centre 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.

8. A truck as defined by Claim 7 and further characterized 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.

9. A railroad car truck comprising a pair of units comprising a wheelset carrying a steering arm, a pair of elongate side frames arranged substantially parallel to a longitudinal direction of said truck and supported by said steering arms, resilient devices interfacing between said steering arms and said side frames, and means joining said steering arms, wherein rotation of a first unit about a vertical axis causes opposite rotation of the second about a vertical axis and said units can move relative to one another in the longitudinal direction of the truck, said means joining said steering arms providing a negligible restoring force over a predetermined amount of rotation or movement of said units.

10. A railroad car truck substantially as hereinbefore described with reference to Figs.

1 to 5 of the accompanying drawings.

11. A railroad car truck substantially as hereinbefore described with reference to Figs.

6 to 1 3 of the accompanying drawings.