EP1789301B1 - Truck for railway vehicles having independent wheels that can be oriented according to the curvature of the tracks - Google Patents

Abstract

This truck comprises: a) a chassis (5) articulated on the body in a manner that enables it to pivot about a vertical axis; b) on either side of this axis, two transverse structures (8a, 8b) supported by said chassis with the ability to pivot about a vertical axis (14), and c); swing arms (10) supporting, at one of the ends thereof, a wheel (12) independent of the others, each arm (10) being articulated by its other end on a horizontal and transverse axis of one of the transverse structures. According to the invention, the vertical articulation (14) on the chassis (5) of each transverse structure (8a, 8b) supporting the swing arms (10) is joined to or at least near the articulation (4) of this chassis (5) on the vehicle body, whereas each structure (8a, 8b) is associated with assisting, pneumatic or hydraulic means controlled by means that compare a reference geometrical axis of the truck with a reference geometrical axis of the vehicle body.

Description

The invention relates to the technical field of railway vehicles equipped with bogies, carriers or engines, and more particularly bogies with four independent wheels. It relates more particularly to a bogie in which the wheels are adjustable according to the curvature of the tracks and possibly have a spacing adaptable to that of the rails of the track.

Traditionally, a railway vehicle, be it a car, a wagon or any other towed or pulled vehicle, is equipped with metal wheels set in rotation at the ends of a transverse axle called "axle-axle". ", Mounted freely in rotation in bearings, the latter being carried either by a vehicle structure, evening by the chassis of a bogie.

Each wheel has a generally frustoconical general shape and is flanked by a flange adapted to come in the interval between the rails of the track and whose outward facing part is called leave. This leave is intended to apply from time to time against the head of the rail to reposition the vehicle transversely.

In a curve of the track, the radius of the curve of the inner rail is smaller than the radius of the curve of the outer rail, so that when the vehicle is traveling on the curve, the two wheels of the same axle-axis have to travel different distances. Now, as they have the same diameters providing the same linear development and are linked by the axle-axis, they can rotate at the same speed. This results in slippage of the wheels relative to the rails, noise, friction and wear of the rail and wheels.

It should be noted here that in curve the flanges of the wheels circulating on the outer rail are the most stressed, since, inside the track, they come into contact with the inner edge and concave shape of the mushroom. outer rail, while, thanks to the curvature, the rolls of the wheels circulating on the inner rail, of convex shape, tend not to come into contact with this mushroom.

The replacement, in each bogie axles axles by independent wheels, rotatably mounted at both ends of arms articulated on the frame of the bogie, allows each wheel to adapt its rotational speed without being hindered by the wheel which it is coaxial. If curved it eliminates the wear by friction and sliding of the wheel tire on the rail, it provides no solution to the friction of the outer rolls of the wheels against the rail head.

To remedy this the document EP648659 describes a bogie in which the chassis, articulated vertically under the body, carries two others vertical joints for two opposing structures each having two horizontal joints, lateral and opposite, for two wheel carrier arms.

By this arrangement, each pair of wheels pivoting about the same transverse axis forms a wheel train which is angularly independent of the other. In this way, when the vehicle enters a curve, the friction of the flanges of the outer wheels against the head of the outer rail forces each of the transverse structures to pivot about a vertical axis by driving the arms carrying the wheels and tending to bring the geometric axis of the coaxial wheels in a position where it approaches the center of the curve of the outer track, with the aim of reducing the friction of the wheels on the rails.

However, in the construction shown and described, each of the two vertical pivot axes of the structures on the frame is in a transverse vertical plane which is closer to the transverse vertical plane containing the axis of the wheels than the transverse vertical plane containing the axis. rotation of the bogie frame. As a result, when moving the vehicle on a curved track, each of the wheel carrier structures is very sensitive to the variations of forces, is unstable and is subjected to numerous yaw movements which impose a control by a complex system of linkages governing the pivoting of each structure relative to its neighbor and with respect to those of the other bogie. These linkages are sensitive to functional play in joints, thermal expansion and require many and frequent adjustments, otherwise they disrupt the pivoting structures.

The present invention aims to reduce the friction between the wheels and rails, but also the noise and wear resulting therefrom, while increasing the adhesion of the wheels on the rails, the load can be towed and overcoming the disadvantages outlined above.

According to this invention, in a bogie according to the definition of the preamble of claims 1 or 2, the vertical articulation on the frame of each transverse structure carrying the articulated arms is merged or at least close to the articulation of this frame on the body of the vehicle, while each structure is associated with pneumatic or hydraulic assistance means, controlled by means comparing a reference geometric axis of the bogie with a reference geometric axis of the vehicle.

The proximity of the hinge axes of the bogie on the body and transverse structures on the chassis improves the stability of the "Bissel" as well constituted, reduces the amplitude of the movements of laces and the influence of the pivoting of the bogie on the position of the vertical axes of the transverse structures, when entering the curve of the vehicle. As a result, compared with the devices of the prior art, the axis common to each wheel train of the same bogie is closer to its ideal position passing through the center of curvature of the track and that Significantly reduced wheel slippage on the rails, but also the friction of the flanges against these rails and noise. In addition, the improvement of the grip of the wheels makes it possible, at equal power, to tow heavier loads.

According to the embodiments, the transverse structures of the frame are articulated around the same vertical axis or around two vertical axes, virtual or real.

In the application to a motorized bogie, each wheel is connected by a transmission of movements to an electric motor arranged between the two articulated arms and whose supply circuit is under the control of electronic means, the said means reacting to currents. provided by means comparing a reference geometric axis of the bogie with a reference geometric axis of the vehicle.

This arrangement makes it possible to continuously adapt the supply current of each electric motor and, consequently, the speed of each wheel, according to the curve of the tracks and the position, inside or outside, of the wheel relative to the curve, and thus eliminates any source of sliding of the wheels on the rails, while increasing the efficiency and the value of the towing load.

In one embodiment, each of the arms is mounted on the extreme cylindrical post of a transverse structure with the possibility of sliding, to adapt the spacing of the wheels to the spacing of the railway and is associated, on the one hand , means controlling the transverse displacement of the arm on the pin and, secondly, means locking the arm in each of its positions corresponding to a track gauge.

• Figure 1 est une en plan par-dessus avec coupe partielle d'une première forme d'exécution du bogie ;
• Figure 2 en est une vue de coté en coupe suivant II-II de figure 1 ;
• Figure 3 et 4 sont des vues partielles de face en bout d'un bogie non motorisé montrant deux formes d'exécution de sa suspension secondaire ;
• Figure 5 est une vue à échelle agrandie, en plan par-dessus avec coupe suivant V-V de figure 2 ;
• Figure 6 est une vue partielle en plan par-dessus des composants d'un bogie apte à circuler sur des voies ayant des écartements différents ;
• Figures 7 et 8 sont des vues en coupe suivant VII-VII de figure 6 montrant, à échelle agrandie, une forme d'exécution des moyens de calage et des moyens de déplacement d'un bras sur son axe ;
• Figure 9 est une vue en coupe suivant IX-IX de figure 7.

Other features and advantages will become apparent from the description which follows with reference to the attached schematic drawing showing several embodiments of the bogie according to the invention.

• Figure 1 is a plan in plan with partial section of a first embodiment of the bogie;
• Figure 2 is a side view in section along II-II of figure 1 ;
• Figure 3 and 4 are partial end-to-end views of a non-motorized bogie showing two embodiments of its secondary suspension;
• Figure 5 is an enlarged view, in plan on top with section following VV of figure 2 ;
• Figure 6 is a partial plan view over the components of a truck capable of traveling on tracks having different spacings;
• Figures 7 and 8 are sectional views along VII-VII of figure 6 showing, on an enlarged scale, one embodiment of the wedging means and means for moving an arm on its axis;
• Figure 9 is a sectional view along IX-IX of figure 7 .

In the drawing the reference numeral 2 designates, in a general manner, the body of a vehicle equipped with two bogies 3, articulated each around a vertical axis 4, real or virtual. The frame of each bogie is constituted by a plate 5 in which transverse walls, respectively vertical 6 and horizontal 7a, 7b, delimit a cage. It contains two opposite transverse structures 8a and 8b formed by sleepers provided with extreme cylindrical studs 9. On these are articulated arms 10, each carrying a wheel 12 adapted to roll on a rail 13.

In the form of execution shown in Figures 1 to 5 , each of the transverse structures 8a and 8b is constituted by a cross member which, V-shaped in the horizontal plane, is articulated near the tip of this V on a common axis or common pivot 14. The latter crosses the wall 7a, on which it is supported by its head, then the two points of the transverse structures, which are offset vertically with respect to each other, and finally the wall 7b.

The figure 1 shows that, when the bogie is on a rectilinear track section, the ends of the transverse structures 8a and 8b carrying the end posts 9 are separated longitudinally by a clearance P, so as to leave them a possibility of pivoting about the vertical axis pivot 14 while limiting this pivoting. This figure 1 also shows that each wheel 12 is integral with its shaft 15 and that it is rotatably mounted, without possibility of translation, in roller bearings 16, carried by the wings of the yoke formed at the free end of the arm 10. The articulation of each arm 10 on its pin 9 is effected by means of a bearing 11, needle or other, shown to figures 1 , 7 and 8 .

• la liaison avec le châssis 5 du bogie articulé autour de l'axe 4,
• l'articulation supplémentaire de correction dans les courbes, cette articulation 14, 114 ou 214 étant confondue ou proche de la précédente, pour limiter les effets de lacet,
• et le support des bras oscillants 10, avec les moyens de suspension 17 et les moyens de freinage associés à chaque roue 12,
• avec, en plus, dans la forme d'exécution des figures 6 à 9, le guidage du déplacement transversal de chaque bras 10 pour ajuster l'écartement des roues 12 à celui des voies 13.

It should be noted that, in the device according to the invention, it is a simple structure, namely each transverse structure 8a or 8b, 108a or 108b, 208a or 208b, which ensures:

• the link with the frame 5 of the bogie hinged about the axis 4,
• the additional articulation of correction in the curves, this articulation 14, 114 or 214 being merged or close to the previous one, to limit the effects of yaw,
• and the support of the oscillating arms 10, with the suspension means 17 and the braking means associated with each wheel 12,
• with, in addition, in the form of execution of Figures 6 to 9 , guiding the transverse displacement of each arm 10 to adjust the spacing of the wheels 12 to that of the tracks 13.

This simplicity makes it possible not only to guarantee the obtaining and the constancy of the sought-after results, but also to free up space which is put to good use for the installation of control means, assistance means, and electric motors. motorization of the wheels.

The primary suspension of each arm 10 comprises damping means 17 which, constituted by a spring or by a hydraulic damper or the like, arranged between plates not shown, are interposed between the arm and the plate 5, as shown figure 2 . The arrangement e these means 17 near the articulation of the arm on the transverse structure 8a, 8b, provides this oscillating arm a great flexibility which improves the adhesion of the corresponding wheel 12.

The body 2 is supported on the chassis 5 of the bogie with the interposition of a secondary suspension constituted either as shown figure 3 , by rubber blocks 18 between an extension 19 of the body 2 and an extension 20 of the wall 7b of the frame, or, as shown figure 4 by rods 22 hinged to the wall 7a and an extension 23 of the body 2. These are techniques well known to those skilled in the art and can be replaced by any other, especially since do not interfere with the means of the invention.

The figure 5 shows another embodiment in which each of the transverse structures is formed by a straight cross member 108a and 108b which is articulated on a vertical pivot, 114a or 114b, distinct from that of the other cross member and distinct from the pivot axis 4 of the chassis 5. The geometric axes of the joints 14 of the same bogie are close to each other and closer to the axis of the vertical articulation 4 than the wheel axis of each set of wheels , as the state of the art discloses by the document EP 648659 . The sleepers are also spaced in the horizontal plane by a longitudinal clearance allowing their pivoting function around their vertical axis 114a and 114b.

With the arrangement described in these two embodiments, when the truck approaches a curve, and as shown in FIG. figure 5 relating to a vehicle traveling in the direction of the arrow 24 on two rails 13e and 13i, the wheel 12A which, on the one hand, is carried by the arm 10 which is forward in the bogie and, on the other hand, runs on the outer rail 13e of the curve, receives, by its flange rubbing on the rail head, a force tending to rotate the transverse structure 108a in the direction of the arrow 25 in the same figure. Similarly, the concavity of the trajectory imposed on the wheels by the rail 13e forces the outer rear wheel 12B to pivot in the direction of the arrow 26.

As a result, the two sets of wheels of the bogie deviate on either side of their transverse median plane PT of an angular value a and b , very low and dependent on the radius of the curve of the track, and that the axes of rotation R1 and R2 of these wheel trains tend to converge towards the center of the curve of the track by putting the outer wheels in a position limiting the friction of the coil with the head of the outer rail 13e. This pivoting is all the more effective because, thanks to the confusion and at least the proximity of the vertical axes 4 and 14, it is insensitive to parasitic forces generating yaw movements, and is assisted by means, hydraulic or pneumatic, described later.

In the embodiment shown in figure 5 each wheel 12 is driven by an electric motor 27 which, thanks to the volume released by the device of the invention, is disposed between the two arms 10 of the wheel set. The casing of each motor is suspended on the plate 5 of the chassis or directly on the body 2. The shaft 15 of each of the wheels of the bogie is connected to a motor 27 by a transmission of movement 28 leading to a shaft 29 protruding from this engine. In known manner, this shaft 29 is itself rotatably connected by a cardan joint 30 to a tubular shaft 32 integral with the motor rotor. This arrangement allows the engine, maintaining a fixed position relative to the body or the bogie, to continue to transmit its movement to the transmission 28, although it oscillates following the movements of the wheels of the truck.

The power supply of each motor 27 is provided by a circuit 33 under the control of an electronic control unit 34. This unit responds to the control currents supplied by circuits 35 coming from means 36 comparing the position of a reference axis of each bogie train with a reference axis of the body.

To the figure 5 , sensors 37 carried by the transverse wall 6 of the chassis and resting on each crossbeam 108a and 108b, all fall under pivoting of these crosspieces and, by the comparator 36 and the housing 34, determine the supply of each motor 27, so that the rotational speed of each wheel is adapted to the curve of the rail on which it rolls. Thus, all the sliding and friction are removed and, with equal power output, a larger load can be towed.

The same results would be obtained with means comparing the longitudinal axis of the frame with the transverse median plane or the longitudinal median plane of each wheel train of the bogie.

It is to simplify the reading of the figure 5 that it represents only on the arm 10 located at the bottom of its left side a braking assembly, while the latter equips each arm 10. This set includes, on the wheel, discs 72, and on the arm 10, pads 73 carried at the ends of jaws 74, articulated at 75 in the arm. These jaws are actuated by a cylinder 76 which, with two opposed pistons, is powered by the pneumatic circuit 46 of the vehicle.

This bogie also comprises means making symmetrical the pivoting of the transverse structures carrying the two sets of wheels of a bogie. In the represented embodiment figure 5 these means comprise convex tooth sectors 38 carried by each transverse structure, centered on the corresponding pivot 114a or 114b and meshing in the inter-structure gap. These means complete the assistance means, pneumatic or hydraulic.

In the form of execution of the figure 5 , the pneumatic assistance means comprise two cylinders 40 each containing two pistons 42, single-acting, mounted in opposition and whose rods 43 are connected to the juxtaposed ends of the structures 108a or 108b, by means not shown. The space between the pistons forms a chamber which is connected by a conduit 44 to a distributor 45 fed by the compressed air circuit 46 of the vehicle. The distributor is controlled by an electrical circuit 47 coming from the comparator 36. Thus, as soon as one of the structures is subjected to a pivoting movement, the comparator 36 delivers signals towards the distributors 45 so that one of them controls the supply of one of the cylinders 40 and the venting of the other. As a result, the pivoting of each of the transverse structures is assisted and is performed substantially symmetrically. It is autonomous and independent of the movements communicated to the structures of the other bogie of the vehicle, in order to avoid any disturbance of the operation due to different positions of the front and rear bogies with respect to the track, rectilinear or curved.

To these means may be associated, on the one hand, biasing means structures 108a and 108b in neutral transverse position, such as springs 48 having their ends connected to the ends of these structures, and, on the other hand, dampers laces 51 arranged on each side and between the juxtaposed ends of the structures. These dampers are constituted by cylinders 49, in which pistons 50, opposed and each connected to one of the transverse structures, can force the air, which they press together, to pass through a nozzle 52 of the cylinder.

In the form of execution of Figures 6 to 9 the cylindrical posts 209a and 209b of the transverse structures 208a and 208b have a length which is greater than the width of the arms 210 so as to allow the transverse sliding of these arms when the vehicle passes over a device for modifying the wheel spacing for adapt them to the gauge of the tracks. Of course, the adjustment stroke C ( Figure 7 ) of each arm is at least half of the difference between the spacings that may be encountered by the vehicle, namely the largest EM spacing, shown on the left of the figure 6 , and the smallest spacing Em, shown on the right side of the same figure.

In this embodiment, the hub 60 of each arm 210 is provided with wedging means in position after adaptation of the spacing. In the form shown in Figures 7 to 9 these means comprise a latch 62 which, C-shaped, is slidably mounted in the hub of the arm and is adapted to penetrate into one of the grooves 63, formed on the end of the post, 209a or 209b. In this embodiment concerning a bogie that can have two wheel spacings, the grooves 63 are two in number, but they can be three in number and even four, depending on the number of spacings that could meet the vehicle and arms have position. The latch 62 is connected to the piston 64, movable in a chamber 61, of a double-acting pneumatic control.

The hub of each arm 210 is also equipped with assisting means and facilitating its transverse displacements on its tenon, at the same time that the wheels circulate on a device tending to move them transversely in the direction of the change of the spacing. To this end, each post 209a or 209b is integral with a piston 65 which, arranged in a cylinder 66 connected to the arm, divides the cylinder into two chambers 67 and 68. Each of these is connected by a conduit to an organ dispenser, such as a pneumatic distributor, not shown.

When the vehicle is traveling, the latch 62 is engaged in one of the grooves 63, for example and as shown in FIG. figure 7 in the groove corresponding to the position for small gauge track, and all these equipment are locked together by electrical means opposing any unwanted operation. To move to a greater distance, it is necessary to feed the pneumatic control, in the direction of the displacement of the piston 64 of figure 9 upwards, to move the latch 62 away from the groove 63 and then feed the chamber 67 of the cylinder 66 to cause the assembly of the arm 210 and the wheel 12 which it carries, in the direction of the arrow 71 of figure 7 . This assistance movement continues until the arm 210 is in the position of the figure 8 , corresponding to the widest gauge. At this point, the latch 62 is lowered into the other groove.

This arrangement considerably reduces the time required for the transformation of the wheel spacing by eliminating all disassembly operations and assembly or replacement of the rolling members and allows to achieve it by rolling at low speed on the adjustment device of the spacing.

• à l'écartement de chaque roue par coulissement de l'extrémité supérieure du bras la portant sur le tenon d'articulation de ce bras, et non par coulissement des boites d'essieu dans l'extrémité inférieure de ce bras,
• à l'interposition d'aiguilles 11 dans les zones de coulissement,
• et à l'assistance des déplacements par des moyens pneumatiques 65 à 68, la modification de l'écartement des roues de chaque train de roues d'un véhicule s'effectue automatiquement sans grands efforts, sans risques de blocage, sans bruits et frottements entraînants des usures, et avec un chantier fixe de guidage des roues simplifié et sans structure de soutien de la caisse pendant la phase d'écartement, mais permettant l'écartement ou le rapprochement des roues d'un train de roues par déplacement du véhicule à vitesse lente.

Thanks:

• at the spacing of each wheel by sliding of the upper end of the arm carrying it on the articulation pin of this arm, and not by sliding of the axle boxes in the lower end of this arm,
• at the interposition of needles 11 in the sliding zones,
• and the assistance of the displacements by pneumatic means 65 to 68, the modification of the spacing of the wheels of each set of wheels of a vehicle is carried out automatically without great efforts, without risks of blockage, without noises and friction compelling wear and tear, and with a fixed fixed wheel guiding site and without support structure of the body during the separation phase, but allowing the spacing or the approximation of the wheels of a wheel train by moving the vehicle at a speed slow.

Of course, these advantages over the modification of the spacing of the wheels of a train are added to those provided by the reduction of friction in the curves, to increase the longevity of the wheel tires.

It is obvious that it is not beyond the scope of the invention by replacing the various pneumatic means described above by equivalent hydraulic means.

Claims (12)

1. Bogie or truck for railway vehicles, having independent wheels that can be orientated according to the curvature of the track, comprising:

   - a chassis (5) articulated to the body (2) about a vertical axis (4),

   - on either side of this axis (4), two transverse structures or cross-members (8a, 8b) supported by this chassis, with the possibility of pivoting about a vertical axis (14),

   - and swinging arms (10) bearing, at one of their ends, a wheel (12) independent of the others, each swinging arm being articulated by its other end on a horizontal and transverse axis of one of the transverse structures, characterized in that the geometric axis of the vertical articulation (14) to the chassis (5) of each transverse structure (8a, 8b) bearing the articulated swinging arms (10) is coincident with the geometric axis of the articulation (4) of this chassis (5) to the body (2) of the vehicle, whereas each transverse structure or cross-member (8a, 8b) is associated with pneumatic or hydraulic assistance means (40 to 45), driven by means (36) that compare a reference geometric axis of the bogie or truck with a reference geometric axis of the body (2) of the vehicle.
2. Bogie or truck for railway vehicles, having independent wheels that can be orientated according to the curvature of the track, comprising:

   - a chassis (5) articulated to the body (2) about a vertical axis (4),

   - on either side of this axis (4), two transverse structures or cross-members (8a, 8b) supported by this chassis, with the possibility of pivoting about a vertical axis (14),

   - and swinging arms (10) bearing, at one of their ends, a wheel (12) independent of the others, each swinging arm being articulated by its other end on a horizontal and transverse axis of one of the transverse structures, characterized in that the geometric axis of the vertical articulation (114a, 114b, 214a and 214b) to the chassis (5) of each transverse structure (108b, 208a and 208b) bearing the articulated swinging arms (10, 210) is closer to the geometric axis of the articulation (4) of this chassis (5) to the body (2) of the vehicle than to the axis of the wheels of each wheel set (12), whereas each transverse structure or cross-member (108a, 108b, 208a and 208b) is associated with pneumatic or hydraulic assistance means (40 to 45), driven by means (36) that compare a reference geometric axis of the bogie or truck with a reference geometric axis of the body (2) of the vehicle.
3. Bogie or truck according to Claim 1, characterized in that each transverse structure (8a or 8b) is in the overall shape of a V and is articulated, near its point, about a vertical axis (14) common with that of the other structure.
4. Bogie or truck according to Claim 2, characterized in that each transverse structure (108a, 108b) consists of a straight cross-member and is articulated mid-way along its length about a vertical axis (114a, 114b) distinct from the axis of articulation of the other cross-member, but close to it.
5. Bogie or truck according to Claim 1, characterized in that each wheel (12) is connected, by a means that transmits motion (28), to an electric motor (27) positioned between the two articulated swinging arms (10) and the supply circuit of which is under the control of electronic means (34) that react to control currents supplied by means (36) that compare a reference geometric axis of the bogie or truck with a reference geometric axis of the vehicle.
6. Bogie or truck according to Claim 2, characterized in that the articulated transverse structures (108a, 108b) are connected by return means (48) returning them to a neutral central position.
7. Bogie or truck according to Claim 2, characterized in that, on each side of the chassis, the ends of the transverse structures (108a, 108b) are connected to one another by yaw dampers (51) comprising a cylinder (49) in which two opposing pistons (50), each connected to one of the transverse structures, force the air compressed between them to pass through a nozzle (52).
8. Bogie or truck according to Claim 2, characterized in that the assistance means comprise, positioned between each of the juxtaposed ends of the transverse structures (108a and 108b), a cylinder (40) containing two single-acting pistons (42) mounted in opposition and the rods (43) of which are connected to the end of one of the structures (108a or 108b), these two pistons delimiting a chamber (41) which is supplied by a directional control valve (45), controlled by means (36) that compare a reference geometric axis of the bogie or truck with a reference geometric axis of the vehicle.
9. Bogie or truck according to Claim 1, characterized in that the suspension of each swinging arm (10) comprises damping means (17) which are arranged between the arm (10) and the mounting plate of the chassis (5) and near the articulation of the arm to the transverse structure (8a, 8b).
10. Bogie or truck according to Claim 2, characterized in that each of the swinging arms (210) is mounted on the end cylindrical tenon (209a or 209b) of a transverse structure (208a and 208b) with the possibility of sliding so as to adapt the separation of the wheels (12) to the gauge (EM or Em) of the railway track, and is associated, firstly, with means (65 to 68) controlling the transverse movement of the arm (210) along the tenon and, secondly, with means (61 to 64) locking the arm (210) in each of its positions corresponding to a gauge of the track.
11. Bogie or truck according to the combination of Claims 2 and 10, characterized in that each end tenon (209a or 209b) is secured to a piston (65) which, positioned in a cylinder (66) connected to the arm (210), divides this cylinder into two chambers (67 and 68) each connected to a supply member such as a directional control valve.
12. Bogie or truck according to the combination of Claims 2 and 10, characterized in that the means of locking each swinging arm (210) on its axis (209a or 209b) comprise, on the tenon, as many grooves (63) as the arm (210) can adopt positions and, in the arm (210), a C-shaped catch (62) able to enter each groove (63), this catch being slidably mounted in the arm and connected to the piston (64) of a pneumatic control.

Images