CA1052625A - Railway vehicle suspensions with diagonally interlinked axles - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A railway truck having at least one load-bearing member supported on-two live axle wheelsets and including symmetrical suspension structure for damping hunting of the truck and wheelsets, the structure for each wheelset connected to bearings on the wheelset and two rods pivotally connected at each of its ends to the sub-frames for diagonally inter-connecting the wheelsets to couple the yawing and lateral movements of the wheelsets. The sub-frame may be rigid to transmit moments to the wheelset or it may be a pinned structure. The suspension is said to cause inefficient gearing between the wheelsets.

Description

105;~25 This invention relates to railway vehicles and in particular to suspensions for such vehicles. It is applicable to railway vehicles in which a body or super-structure is pivotally supported on bogies and also to railway vehicles in which the vehicle body is supported directly on the wheelsets, e.g. four-wheeled vehicles.
For simplicity this specification uses the term "railway truck" to mean a basic railway unit including at least one load-bearing member supported on at least two wheelsets. Thus a railway truck may be a bogie or a four-wheeled vehicle. Also in this specification the term "load-bearing member" is used to mean the body of a four-wheeled vehicle or to mean one of the frame members of a bogie.
It is an object of the invention to provide suspension structure for a railway vehicle which provides : good dynamic stabilization of the vehicle while at the same time permitting the vehicle to move freely through curves .
Thus, in accordance with the present teachings, a railway truck is provided which has a longitudinal axis in its direction of travel and includes a load-bearing structure, two live axle wheelsets each of which have profiled wheel treads whereby steering forces are generated on curved track, a pair of axle bearings for each wheelset, ; an axle box adaptor which is seated on each bearing with each axle box adaptor being fixed against lateral and longitudinal movement with respect to its bearing.
Rasilient means are provided elastically suspending each axle box adaptor laterally and longitudinally to the load-; be æ ing structure and imposing constraints against yawing movement of each wheelset relative to the load-bearing structure which are lower than the steering forces generated on the wheelset on curved track whereby each wheelset is self-steering and means provided interconnecting the wheelsets to couple yawing movements of the wheelsets in opposite senses thereby to counteract hunting of the wheelsets while

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The interconnecting means comprises a first arm secured against rotation in a horizontal plane to the axle box adaptor on the first wheel set, an identical second arm secured against rotation in a horizontal plane to the diagonally opposite axle box adaptor on the second wheel-set and a rod which extends diagonally across the truck pivotally connected to the free end of the first and second extension members.
In accordance with a further embodiment a railway truck is provided which has a longitudinal axis in its direction of travel and includes a load-bearing structuxe, `~
a pair of live axle wheelsets each equipped with a pair of hearings and each having profiled wheel treads, an axle box adaptor for each bearing and load-transmitting means being provided suspending each axle box adaptor to a load-bearing member and imposing a low yaw constraint on each of the wheelsets relative to the load bearing structure whereby a low yaw contraint in combination with the profile o the wheel treads make each wheelset self-steering. Means are provided interconnecting the wheelsets to couple their yawing movements in opposite senses thereby to counteract hunting of the wheelsets with the interconnecting means comprising a pair of arms for each wheelset, each arm being connected to the axle box adaptor. A cross-beam is connected between the arms of each wheelset to form the arms of a sUb-frame on the wheelset and two rods are provided which cross ; one another pivotally connected between the sub-frames of the -~ wheelsets.
By a more specific embodiment of the present teachings, there is provided a radial railway truck which ~ includes a pair of live axle wheelsets each of which are - equipped with a pair of axle bearings and each have profiled wheel treads whereby steering forces are generated on curved track. ~n axle box adaptor is provided for each axle bearing '`I
wherein each axle box adaptor comprises a web seated on the -` bearing and a pair of supports depending from the web and ., .

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.~. ~ , , lOS'~25 straddlin~ the bearing with each support presenting an upwardly facing seat for a load-transmitting member. A
pair of side frames is provided each of which is formed with a central opening which has a base wall forming a seat for supporting a bolster, spring means are provided ~upporting each side-frame on the seats of each axle box adaptor and imposes sufficiently low magnitude constraints against yawing movement of each wheelset with respect to the side-frames whereby each wheelset can assume substantially radial po~itions during curving. A bolster formed with two diagonally extending clearance spaces is provided with spring means supporting the bolster on the seats of the side-frames.
An arm is provided extending from each axle box adaptor towards the bolster in clearance relation to the side-frame with anchor means provided pivotally connected between arms of diagonally opposed axle box adaptors, the anchor means pass freely through the diagonally extending clearance spaces in the bolster.
Preferably to ensure that turning movements are txansmitted between interconnected wheelsets two extension members are connected to each wheelset, a beam is connected between each extension member of each wheelset to form with the extension member, a sub-frame on the wheelset, and two rods, which cross each other, are diagonally connected to each of the sub-frames of the interconnected wheelsets.
The extension members may extend from each adaptor in a direction inclined relatively to the longitudinal axis of the truck. Also a line between the pivotal connection of a rod to a sub-frame and the bearings to which the sub-frame is connected may be inclined relatively to the longitudinal axis of the truck. The connections between each extension member and each beam and between each extension member and each bearing may be pivotal.
To illustrate the invention further several embodiments of railway truck constructed according to the ; invention are now discussed with reference to the accompanying drawings, in which:-- a-D;
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, 105'~6Z5 Figure 1 is a side elevation with parts broken away of one embodiment of the truck of the invention, Figure 2 is a plan view of the embodiment of Figure 1 with parts broken away for clarity, Figure 3 is a schematic plan view of the embodiment of Figures 1 and 2, .
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105'~ 5 Figure 4 is a schem~tic plan view of another embodiment of rai1~ay truck of the invention, Figure 5 is a schematic plan view of yet another embodiment of a railway truck of the invention, Figure 6 is a schemat~c plan view of yet another embodiment of the railway truck of the invention, Figure 7 is a schematic plan view of another embodiment, Figure 8 is a schematic plan view of a further embodiment, Figure 9 is a side elevation in sect;on of a means for o damping two rods which cross each other relatively to each other, and F~gure 30 is a perspecti~ve view of the means of Figure 10.
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Figures 1 to 3 of the draw~ngs show a three-piece bogie fnciudi~ng two side-frames 10 and a bolster 12 supported by coil springs i4 on the side-frames 10. The bolster is ; essentially of a hollow, elongate box construction. The side-~rames 10 rest on two wheelsets 16 each comprising a pa~r of wheels 18 fast or sol~dly mounted on an axle 20.
The axle rotates in beari~ngs 22. Each bearing 22 is connect-~o ed to a s~de-frame 10 by a pad 24 having an arcuate lower surface which rests on the bearing 22, an axle box adaptor 26 which rests on an upper surface of the pad 24, and two rubber sandwich elements 28 which are mounted on the axle box adaptor 26 and whi~ch i~n turn support the. side-frames 10. Each rubber sandwi~ch ele~ent 28 comprises alternate layers of rubber and metal plate. The bolster has a conventional female wear - plate 66 for p~votally supporti~ng a superstructure. ~ -Each axle box adaptor 26 is channel shaped in cross-section and comprises a web 30 which rests on a pad 24 and two horizontal 3O supports 32, 34 on opposed sides of the web 30 so that the :.' Y'~

lOS'~Z5 supports straddle a bearing 22. A depending flange ~6 is secured to the sup.port 34 to provide a mounting for a key 38 which prevents the bearing from bejng separated from the axle box adaptor 26 in the event of excessive relative vertical movement between the axle box adaptor and bearing. A pin 29 passing through registering holes in the axle box adaptor 26 and a ~
relatively larger hole in the side-~rame 10 is provided to hold the axle box adaptor to the side-frame in the event of gross relative movement. The supports 32, 34 of the axle box adaptor `-are equally spaced from the horizontal plane passing through the ~ -axis of the axle 20, with the support 32 being located below and the support 34 being located above the horizontal plane. This ~-ensures that when forces are applied to the axle box adaptor it does not rotate in a vertical plane. The pad 24 may be welded to the bearing, alternatively the pad 24 may be a snug fit between the walls of the axle box adaptor 26 which straddle the pad 24.
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When the Wheelsets of the truck are interconnected by a diagonal interconnection which comprises-a U-shaped extension member 40-secured to each axle box adaptor 26, a beam 42 connected between ~o the free ends of the extension members on a wheelset to form with the extension members a sub-frame 37 on the wheelset, and two rods, ; which cross each other, pivotally connected to the sub-frames 37 by pin ~oints 48. Each extension member comprises a plate 39, which passes through a hole 15 conventionally formed in the side-frame 10, and struts 41 which secure the plate 39 to the sides of the axle box adaptor 26. m e beam 42 is connected to the plates 39 of the extension members 40. The rods 46 pass through slots in the bolster, the slots being sufficiently wide and deep to ensure that the rods do not contact the bolster on relative movement of 30 the rods and the bolster to one another. The beam, inter alia, acts to prevent significant convergence or divergence of the extension members when the wheelsets move longitudinally relatively to each other.

105'~:625 Single-acting brakes 64 are provided for each wheel. Brake beams and the like for the brakes have not been sho~ln.

Each wheel has a profiled tread, i.e. does not have a straight taper, and the profile is such that the wheel has a high effective con;city which is greater than 1/20.
The elastomeric elements 28 impose a yaw constraint on the wheelsets which is sufficiently low to permit each wheelset t6 attain a radial position in a curve. The relationship.
between the wheel tread conicities and the yaw constraints of the element 28 is such that each wheelset is substan-tially self-steering in the curves in which the truck is to be used. South African patent No. 72/7978 discloses the relationship between the con-icities-and the yaw con-straints necessary to obtain self steering.

" 15 The diagonal interconnection is resilient bet~een ~ the wheelsets, the elasticity b.eing in the range : from 3,x 106 N/m to 3x107 N/m (1.7x~04 ~o 1.7xlO51bf/in). This '., elasticity is essential for the diagorlal interconnection t,o act as a hunting,stabilizer. If sufficient elasticity cannot be obtained from the materials'of the diagonal inter-connection, then rubber or other types of.elastomer may be pro,vfded at the pin joints.
. ,~ ' -~ South African Patent No. 72/7978, discloses how the diagonal..interconnecti.on..may;.be used to obtain hunting ''- 2s- stability even at h-igh speeds in a truck in which the wheel-' , se.ts have such high effective conicit.ies and-such low yaw constraints to.allow them to be-self-'steering. --~Jith the ,'~ stnucture' disc.losed in 'patent Wo. 72/7978 there-are difficul-ties.in adapting the. diagona;l-.interconnection to conventional 'i 30 and/or existing bogies;. This inYention discloses structure ",-` which is more practic.a,l .i.n.terms of total cost, manufactur-ing requirements and.adaptation to existing or conventional ., , -- 6 --.

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bogies than the structure of patent No. 72/7978. For example the wheelsets are interconnected by rods which may be solid, tubular or any other section, which rods are simply pin-poined to the sub-frames on the wheelsets. Each slub-frame 37 is constructed of simple-section beams 42, plates 39 and angle iron 41. The axle box adaptors 26 are cast or formed from welded plates. These simple components should be compared with the construction of Bissell frames or anchors integral with the adaptors as shown in patent No. 72/7978.
The diagonal interconnection is easily adaptable to any type of bogie having a bolster. For example the plates 39 of the extension members 40 pass through the holes 15 conventionally formed in the side-frames 10, and the rods 46 pass through solts s~mply cut into a conventional bolster.

In addition to the constructional advantages, the inventor has found experimentally that the diagonal interconnection ; of the invention provides add~tional hunting stabilization for a truck over that dlsclosed in S.A. patent No. 72/7978.

As yet, because of the complicated interaction of the elements in the interconnectlon, the inventor has not been able to : formulate a definite theory to explain why the diagonal inter-connection of the inventi`on ~s so effective. One possible explanation hinges on consi~der~ng the diagonal interconnection to be a gear which transmits moments and forces between the interconnected wheelsets. Thus if one wheelset oscillates or is perturbed the gear transmits the movement to the other wheelset and in so doing exerts reactive forces on both the respondir,g and perturbed wheelsets. The definition of responding and perturbed wheelsets will alternate when both the wheelsets are oscillating.
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If the mechanical efficiency of the gear for transmitting moments and forces is termed to be E, then it can be shown ' - ' ' , , , :

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mathematica~ly that the forces which tend to stabilize hunting for one ~Yheelset will be proportional to (1 ~ E) and for the other wheelset will be proportional to (1 - E).
Thus, if the efficiency is very high and approaching one, such as may be obtained with the diagonal inter-connections of S.A. patent No. 72/7978, then ;t can be seen that the stabil~zing force on one wheelset will be high and on the other wheelset will be minimal. If, however, the gear is made inefficient, then both wheelsets receive o significant, but different stabilizing f~rces. This has a net stabilizing effect which is greater than when the gear is very efficient. It is believed that the forces on the wheelsets obtained through the diagonal interconnection ?
cause stabilizing creep forces to be generated in the contact areas between the wheels and the track.

The efficiency for transmitting mo~:ents of the diagonal inter-connection can be adjusted by changing the direction in which the extension members project, the inclination of the extension members to the longttudinal axis of the truck, the ~o lengths of the extension member or the positions of the pivotal connections of the rods 46 to the sub-frames 37.
In addit~on the eff~c~ency can be reduced by makin~ the pad 24 smaller than the inside cross-section of the axle box adaptor 26 so that the axle box adaptor 26 and pad 24 can-slide and rotate relatively to each other. A clearance of about 2 to 5 mm (5/64 to 1/5 inch) has been found to be sufficient. The interferring surfaces of the pad 24 and axle box adaptor 26 should be such that they can rub against each other. The frictional force between the rubbing surfaces of the pad and adaptor is dependent 3a on the vehicle load. With this construction the axle box adaptor 26 can be ~onsidered to be pivotally connected to the wheelset.

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! o Since the diagonal interconnection can now be made ; effective for stabilizing hunting, the elastic constraint on the wheelsets relative to the truck cdn be decreased to allow each wheelset greater freedom to yaw in a 5 curve as the elast~c constraints are no longer the sole means of damp~ng wheelset hunting. The elastic constraints may even in appropriate situati~ons,as will be appreciated by persons skilled i~n the art, be reduced to zero.
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,~ The effi~ciency of the d~agonal interconnection can be ~'~ 10 tailored to "tune out" or avoid resonan,ce like instabilities of the bogie and body mounted on the bogie.

In Figure 4, which shows schematically a truck having a ~, construction similar to that of Figures 1 to 3, but ~ with the sub-frame 37 located outside the wheelsets of the ,'~ 15 truck.
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Figures 5 to 9 show var~ous constructions of diagonal , ~nterconnection which can be used for vary~n~ its mechanical . efficlency for transmltting moments and forces and thus j its hunt~ng stab~lizing effect on the truck.
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20 In Figure 5, the sub-frame 37 on each wheelset is formed by extens~on members 40 and a beam 52 fixed to the extens~on members. The beam 52 projects beyond the extension members. Holes 54 for receiv~ng the pin of a pin joint are formed in the beam 52. The rods 46 can be pivotally joined 25 to the beam 52 at any of the holes 54, the holes being used belng symmë'tr~cal relati~vely to the truck.

Figure 6 shows a variation of the diagonal interconnection '~ of Figure 5 in which the extension members are inclined ~ 30 relatively to the longitudinal axis of the truck.
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In the constructions of Figures 3 to 6 each extension member is secured to the ~heelset so that ;t can transmit r~oments to tl~at wheelset. For this reason the beam 42 on each wheelset may be omitted without changing the e1'fectiveness of the diagonal interconnection.

Inl a modification of the embodiments of Figures 3 to 6 the beam 42 may be pivotally connected to i~s extension members 40 by means of pin-joints, rivets or welding.
This construction has particular advantage in the em~odi~ents of Figures 3 and 4 in ~hich the extension members 40, beams 42 and rods 46 can be interconnected by a single pin-joint or the l~ke.
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'.F~gure 7 shows a var~at~on of the construction of the sub-frame 37 in whtch each extension member is pivotally connected at 56 to a bearing of a wheelset and ls also pivotally connected at 58 to the beam 52. The pivotal connections 56 and 58 can be pin joints, rivetted joints or the like which permit a'small amount of relative pivotal movement. The pivotal connection 56 is over the centre of the bearing 22 so that each extension member is rotatable about a vertical axis'approximately over the centre of the bearfng 22.

The pivotal connection 56 between each extension member 62 and its bearing 22 can be formed by making the pad 24 rotatable relatively to the axle box adaptor 26 with the extension member secured to the axle box adaptor. To make the pad and axle box adaptor of Figure 1 rotatable relatively to each other a lateral and longitudinal clearance is provided between them and suitable rubbing surfaces are provided where the axle box adaptor rests on the pad.

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lOS'~25 ) O In Figure 8 there is shown a variation of the diagonal ; intercorlnection of Figure 7. In this embodiment each extension member 62 ;s connected to its beam 52 in such a manner that it lies inclined relat;vely to the longitudinal axis of the truck. Here, if one wheel set moves laterally relatively to the other wheelset, then because of the interconnection of the sub-frames the wheelset moves, in effect, laterally relatively to its ¦ beam 52. This causes one of the extension members 62 to push the ends of the wheelset and beam closest to it ~ away from each other and the other member 62 to pull that ¦ end of the beam and wheelset together. Th~s forces the wheelset into a pos~tion where stabilizing creep forces are generated in the contact areas between the wheel and the track.

With either of the embod~ments of Ftgures 6 and 8, the extension members can either project outwardly or inwardly of the truck as shown ,., The inventor has also found that it is desirable to damp the rods 46 relatively to each other. In Figures 9 and 10 there is shown a means 70 for damping the rods relatively to each other. The means 70 comprlses a first plate 72 , secured to one of the rods 46, a second plate 74 secured to the other of the rods 46, and a third plate 76 connected to the first plate 72 so as to interpose the second plate 74 - between ttself and the first plate 72. Each of the plates 72, 74 and 76 have four through-holes 78 which are in register, the holes in the second plate being of larger . ~ , ~ diameter than the holes in the first and third plates.
, . , Bolts 80 pass through the holes. In order to ensure a good sliding fit of the bolts 80 in the holes 78 a brass or Nylon bush 84 passes through each hole in the first plate and extends towards the th~rd plate 76. A bush 86 of ,., " ~ '.

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smaller diameter an~ slidable axially in the bush 84 is inserted 1 through the bush 84. The bush 86 is a snug f;t around the bolt f 80 and is collnected to the plate 76. A nut 8~ and washer 90 is engaged with each bolt 80 with a spring 92 being provided between the washer and the third plate 76.

In use, each nut 88 is tightened onto its bolt to compress the spring 92 and prestress the first and third plates together.
The rods 46 are permitted a small amount of relative movement, both rotational and sliding, because of the large clearance j 10 holes in the second plate. Any movement is frictionally resisted by the rubbing of the second plate against the first and third plates.

A single bush may also be used in place of the telescopic bushes 84, 86. In this event the bush would be secured to the plate 72 and would be a sliding fit in the plate 76. Thus the plate 76 would be movable towards and away from the plate 72, but would be guided laterally relatively to the plate 72.

As is known huntiny stability is at its worst in railway vehicles which are ligh~tly loaded or empty. For this reason ;~ 20 the prestress imposed by the compression of the spring 92 is selected for optimum hunting stability of the vehicle when it is lightly loaded.
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In-~h~e just described embod~ments the b~arings 22 are located outside the wheels. The bearings may, of course, be located between the wheels of a wheelset, i.e. inboard, with the extension members still being connected to the bearings.
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While it is most con~enient to attach the extension members 40 to the bearing 22 which support the load-bearing members, such - as side-frames of a bogie or the body of a four-wheeled vehicle, the extension members may be connected to separate bearings provided specifically for that purpose. In a vehicle in which the wheelsets are driven by an electric motor mounted on bearings on the wheelset, then the extension members may be connected to the casing of the motor.
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Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1.
A railway truck having a longitudinal axis in its direction of travel and including:
a) a load-bearing structure;
b) two live axle wheelsets each having profiled wheel treads whereby steering forces are generated on curved track;
c) a pair of axle bearings for each wheelset;
d) an axle box adaptor seated on each bearing, each axle box adaptor being fixed against lateral and longitudinal movement with respect to its bearing;
e) resilient means elastically suspending each axle box adaptor laterally and longitudinally to the load-bearing structure and imposing constraints against yawing movement of each wheelset relatively to the load-bearing structure which are lower than the steering forces generated on the wheelset on curved track whereby each wheelset is self-steering;
and f) means interconnecting the wheelsets to couple yawing movements of the wheelsets in opposite senses thereby to counteract hunting of the wheelsets while avoiding inter-fering with their natural self-steering ability, the inter-connecting means comprising a first arm secured against rotation in a horizontal plane to an axle box adaptor on the first wheelset, an identical second arm secured against rotation in a horizontal plane to a diagonally opposite axle box adaptor on the second wheelset and a rod extending diagonally across the truck pivotally connected to the free ends of the first and second extension members.

A railway truck as claimed in claim 1, in which each axle box adaptor comprises a web seated on the bearing and a pair of supports depending from the web and straddling the bearing, each support presenting an upwardly facing seat for a resilient member which in turn supports the load-bearing structure.

A railway truck having a longitudinal axis in its direction of travel and including:
a) a load-bearing structure;
b) a pair of live axle wheelsets each equipped with a pair of bearings and each having profiled wheel treads;
c) an axle box adaptor for each bearing;
d) load-transmitting means suspending each axle box adaptor to a load-bearing member and imposing a low yaw constraint on each of the wheelsets relatively to the load-bearing structure, whereby the low yaw constraint in combination with the profile of the wheel treads makes each wheelset self-steering;
and e) means interconnecting the wheelsets to couple their yawing movements in opposite senses thereby to counteract hunting of the wheelsets, the interconnecting means comprising a pair of arms for each wheelset, each arm being connected to an axle box adaptor; a cross-beam connected between the arms on each wheelset to form with the arms a sub-frame on the wheelset;
and two rods which cross one another pivotally connected between the sub-frames of the wheelsets.

A railway truck as claimed in claim 3, in which the load transmitting means includes a resilient element for imposing resilient constraints to yawing and lateral movement of each wheelset with respect to the load-bearing structure.

A railway truck as claimed in claim 3, in which each axle box adaptor is so attached to its bearing that it cannot rotate in a horizontal plane with respect to the bearing.

A railway truck as claimed in claim 3, in which each axle box adaptor is rotatable in a horizontal plane with respect of its bearing.

A railway truck as claimed in claim 3, in which each arm of a pair of arms comprises two longitudinally extending struts each strut being secured to an axle box adaptor at one end and being connected to the other strut of that pair of struts at its other end.

A railway truck as claimed in claim 3, in which each axle box adaptor comprises a web seated on a bearing and a pair of supports depending from the web and straddling the bearing, each support presenting an upwardly facing seat at its lower end for supporting a load-transmitting means which in turn supports a load-bearing member.

9.
A railway truck as claimed in claim 3, in which each arm on each wheelset projects generally towards the other wheelset to which the wheelset is interconnected.

10.
A railway truck as claimed in claim 3, in which each pivotal connection of each rod to each sub-frame is laterally offset from a line parallel to the longitudinal axis of the truck and passing through the bearings of the two wheelsets.

A railway truck as claimed in claim, 3, in which each arm, in a horizontal plane, is inclined relatively to the longitudinal axis of the truck.

A railway truck as claimed in claim 3; in which for each sub-frame the cross-beam is pivotally connected to its arms.

A railway-truck as claimed in claim 3, including damping means acting between the rods which cross each other to damp movements of the rods relatively to each other.

A railway truck as claimed in claim 13, in which the damping means comprises a first element having a substantially planar surface connected to one of the rods which cross each other.
a second element having a substantially planar surface connected to the other rods with the planar surfaces of the first and se-cond elements frictionally coupled to each other, and means to prestress the elements against each other.

A radial railway truck including a pair of live axle wheel-sets each equipped with a pair of axle bearings and each having profiled wheel treads whereby steering forces are generated on curved track; an axle box adaptor for each axle bearing, each axle box adaptor comprising a web seated on the bearing and a pair of supports depending from the web and straddling the bearing with each support presenting an upwardly facing seat for a load-transmitting member; a pair of side-frames each of which is formed with a central opening having a base wall forming a seat for supporting a bolster;
spring means supporting each side-frame on the seats of each axle box adaptor and imposing sufficiently low magnitude constraints against yawing movement of each wheelset with respect to the side-frames whereby each wheelset can assume substantially radial positions during curving; a bolster formed with two diagonally extending clearance spaces; spring means supporting the bolster on the seats of the side-frames;
an arm extending from each axle box adaptor towards the bolster in clearance relation to the side-frames; and anchor means pivotally connected between arms of diagonally opposed axle box adaptors, the anchor means passing freely through the diagonally extending clearance spaces in the bolster.

A radial railway truck as claimed in claim 15, in which each side-frame is formed with a pair of openings flanking the central opening, pairs of diagonally opposed openings being in register with one another and one of the diagonal clearance spaces formed in the bolster.

A radial railway truck as claimed in claim 15, in which each arm comprises a pair of generally longitudinally extending struts which flank a side-frame in clearance relation, each strut being secured to an axle box adaptor at one end and being connected by a cross-member to the other strut at its other end and with the cross-member passing freely through an opening formed in the side-frame.

A radial railway truck as claimed in claim 15, in which the upwardly facing seats of each axle box adaptor are vertically staggered and the side-frames are formed with a pair of downwardly facing seats towards each end, the downwardly facing seats of the side-frames being complementally staggered to the upwardly facing seats of the adaptors.