Side bearer

Abstract

 A side bearer comprises a lower component 10, an upper component 20 guided for movement relative to the lower component 10, biassing means 18 urging the upper component 20 away from the lower component 10, and a friction plate 28 pivotally carried by the upper component 20.

Description

[0001] This invention relates to a side bearer for use on a railway vehicle.

[0002] It is usual to mount side bearers between a railway bogie and the associated vehicle underframe to restrict or damp movement between the underframe and the bogie. A typical side bearer comprises a lower component secured to, for example, the bolster of the bogie, and an upper component guided for movement in the vertical direction relative to the lower component, springs being located between the components. The upper component carries a bearing plate arranged to engage a surface of the vehicle underframe.

[0003] In use, two such side bearers are used on each bogie, the side bearers being located symmetrically upon the bolster of the bogie, one being located on each side of the central pivot of the bogie. The side bearers serve to control sideways tilting movement of the vehicle whilst at the same time allow the vehicle to pass around curves in the railway track.

[0004] In the event of pitching or rolling movement of the vehicle, the underframe may move out of contact with the bearing plate of the associated side bearer, thus reducing friction between the bogie and the underframe of the vehicle, and this is thought to be undesirable as relative movement between the underframe and the bogie is damped inconsistently. Additionally, in curving movement of the vehicle the resultant angular movement between the underframe and the bogie may not be friction damped initially, in the longitudinal direction, due to the presence of air gaps within and between the components of the side bearer which must be taken up before friction damping occurs.

[0005] According to the present invention there is provided a side bearer comprising a lower component, an upper component guided for movement relative to the lower component, biassing means urging the upper component away from the lower component, and a friction plate pivotally carried by the upper component.

[0006] As the friction plate is pivotable relative to the upper component, the side bearer can move to ensure that the side bearer remains fully in engagement with a surface of an associated vehicle underframe, in use, even in the event of such tilting, rolling or pitching motion occurring, thereby enabling consistent damping of motion.

[0007] The biassing means conveniently comprise springs.

[0008] The design is such that all relative angular motion is friction damped, even when the angular motion is very small.

[0009] Bump stops are preferably provided to limit movement of the upper and lower components towards each other.

[0010] Preferably, the ends of the friction plate are free to move through a vertical distance of ±5mm relative to the upper component, the friction plate thus being allowed to tilt through an angle of approximately ±3½°.

[0011] The invention will further be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a view, partly in section, illustrating a side bearer in accordance with one embodiment of the invention, and

Figures 2 and 3 are sectional views along the lines 2-2 and 3-3 of Figure 1, respectively.

[0012] The side bearer illustrated in Figures 1-3 comprises a lower component in the form of a base plate 10 arranged to be secured, in use, for example by bolting, to the bolster or the like of a bogie. Secured to the base plate 10 is a spigot 12, the spigot being arranged to upstand from the base plate 10 and being secured in position, for example, by welding. In addition to the spigot, the base plate 10 further carries a pair of guide members 14, the guide members 14 being spaced from the spigot 12 on opposite sides thereof and including vertically extending walls 16 which extend parallel to one another.

[0013] The base plate 10 carries a pair of springs 18 which, in turn, support an upper component 20 which is of generally planar form, but includes a centrally located, downwardly extending projection 22 which is formed with a bore 24 into which the spigot 12 extends. The projection 22 is of generally square cross-section as can be seen in Figure 2, and is dimensioned to fit between the walls 16 of the guide members 14. Stop members 26 are carried by the base plate 10 and arranged to engage the lower surface of the component 20 upon a predetermined amount of downward movement of the component 20 relative to the base plate to limit such movement.

[0014] The component 20 carries a friction plate assembly 28 which comprises a friction plate 30 carried by a carrier member 32. The friction plate assembly 28 is pivotally carried by the component 20 so as to allow tilting movement of the friction plate assembly 28 relative thereto. As shown in Figures 1 and 3, the carrier member 32 includes, on its lower surface, a projection 34 having a surface 36 of part-cylindrical form which is arranged to bear against a similarly shaped recess 38 formed in the upper surface of the component 20. As shown in Figure 3, the recess 38 formed in the upper surface of the component 20 into which the projection 34 extends is closed ended, thus ensuring that the mounting plate 32 is held against lateral movement relative to the component 20.

[0015] In use, the friction plate 30 engages against an associated surface mounted upon or forming part of the vehicle underframe of the associated wagon body or the like.

[0016] The fit of the spigot 12 within the bore 24 is chosen so as to substantially prevent longitudinal movement between the base plate 10 and the component 20. Further, the fit of the projection 22 between the walls 16 of the guide members 14 substantially prevents angular, or twisting movement of the component 20 relative to the base plate 10. It will be appreciated, therefore, that the component 20 is restricted to be able to move only in the vertical direction relative to the base plate 10. As mentioned briefly hereinbefore, the mounting plate 32 is capable of pivoting movement relative to the component 20, but longitudinal or lateral movement of the mounting plate 32 relative to the component 20 is not permitted or is restricted to a very small amount. It will be appreciated, therefore, that although the wear plate 30 of the assembly 28 is capable of pivoting movement relative to the base plate 10, and is also capable of vertical movement relative to the base plate 10, longitudinal or lateral movement of the wear plate 30 relative to the base plate 10 is restricted to a very small amount. Such limiting of longitudinal movement whilst allowing vertical and pivoting movement ensures that constant friction is maintained between the bogie and the wagon body supported by the side bearer, even in the event of rolling or pitching motion ofthe wagon body or angular movement between the bolster and vehicle underframe occurring, thus consistent damping can be achieved. Typically, two such side bearers will be provided on each bolster, the side bearers being arranged symmetrically on opposite sides of the bogie pivot point.

[0017] Although the magnitude of the tilting movement through which the assembly 28 is capable of articulating may be varied, in the embodiment illustrated the ends of the carrier member 32 are capable of tilting through a distance of plus or minus 5mm in the vertical direction, this distance equating to an angular tilting motion of approximately 3½°. It is thought that this level of tilting movement of the friction plate 30 will allow for the pitch and roll of the wagon body which typically occurs, in use, but obviously the design may be modified to allow for a greater or smaller amount of movement, if desired.

[0018] Although a specific arrangement of side bearer has been described hereinbefore, it will be appreciated that a number of modifications or alternations may be made thereto within the scope of the invention.

Claims

1. A side bearer comprising a lower component, an upper component guided for movement relative to the lower component, biassing means urging the upper component away from the lower component, and a friction plate pivotally carried by the upper component.

2. A side bearer according to Claim 1, wherein the biassing means comprise springs.

3. A side bearer according to Claim 1 or Claim 2, further comprising bump stops to limit movement of the upper and lower components towards each other.

4. A side bearer according to any one of the preceding claims, wherein the ends of the friction plate are free to move through a vertical distance of ±5mm relative to the upper component.

5. A side bearer according to any one of the preceding claims, wherein the friction plate is allowed to tilt through an angle of approximately ±3½°.

6. A side bearer according to any one of the preceding claims, wherein pivoting movement of the friction plate is permitted about only a single pivot axis.

7. A side bearer according to any one of the preceding claims, wherein the upper component is permitted to move towards and away from the lower component, but lateral and angular movement is restricted.

8. A side bearer according to Claim 7, wherein relative angular movement between the upper and lower components is restricted by a projection associated with one of the upper and lower components engaging walls associated with the other of the upper and lower components.

Drawing