[0001] This invention relates to a rocker arrangement suitable for use in a railway vehicle.
[0002] One design of railway vehicle includes a pair of side frames each of which defines
a pair of pedestals. A saddle is associated with each pedestal, the pedestal being
supported by the associated saddle through a number of suspension springs. Relative
vertical and horizontal movement between the saddle and the associated pedestal is
damped by means of friction wedges which are urged against angled surfaces of the
pedestal by some of the suspension springs and bear against generally vertically extending
surfaces of the saddle.
[0003] Each saddle is carried by an axle and wheel set through a rocker arrangement which
typically comprises a component having a part-spherical surface mounted within the
saddle, and an adaptor member arranged to co-operate with the axle or bearing of the
wheelset and having a dished surface into which the said component extends and against
which the part-spherical surface bears to allow the saddle and its associated springs
to articulate relative to the adaptor member and wheelset. It is thought that it may
be desirable to damp the operation of the rocker arrangement.
[0004] According to the present invention there is provided a rocker arrangement comprising
a rocker member and an adaptor member, the rocker member and the adaptor member having
co-operating surfaces arranged to allow the rocker member to tilt relative to the
adaptor member, and a resiliently deformable component arranged to apply a restoring
force in the event of tilting of the rocker member relative to the adaptor member.
By this means lateral accelerations of the wheelset are better reacted by the tilting
operation of the rocker and saddle.
[0005] The resiliently deformable component conveniently includes first and second deformable
elements located on opposing sides of the co-operating surfaces. The deformable elements
may be interconnected, for example by being mounted upon a common support plate. The
elements are conveniently blocks of rubber or rubber-like material.
[0006] The rocker member is conveniently shaped to define a part-spherical projection arranged
to extend into a dished part of the adaptor member.
[0007] The invention will further be described, by way of example, with reference to the
accompanying drawings, in which:
Figure 1 is a view illustrating part of a railway vehicle incorporating a rocker arrangement
in accordance with an embodiment of the invention; and
Figures 2 and 3 are sectional and side views illustrating the rocker arrangement of
the vehicle of Figure 1.
[0008] The railway vehicle illustrated in Figure 1 comprises a pair of side frames 10, part
of only one of which is illustrated, each side frame 10 being shaped to include a
pair of pedestals 12. Each pedestal includes a pair of inclined surfaces 14 defining
therebetween a cavity into which part of a saddle 16 extends. Suspension springs 18
are provided between the saddle 16 and the pedestal 12 to support the pedestal 12
the suspension springs 18 allowing some vertical and horizontal movement of the pedestal
14 relative to the saddle 16.
[0009] A pair of friction wedges 20 are provided, each wedge 20 being urged by some of the
suspension springs 18 into engagement with the angled surfaces 14 of the pedestal
12, the arrangement being such that the friction wedges 20 are urged into engagement
with substantially vertical surfaces 22 of the saddle 16, the friction wedges 20 serving
to damp vertical and horizontal movement between the pedestal 12 and the saddle 16.
[0010] The saddle 16 is carried by an axle 24 of a wheelset of the vehicle through a rocker
arrangement 26.
[0011] As shown most clearly in Figures 2 and 3, the rocker arrangement 26 comprises an
adaptor member 28 arranged to co-operate with the axle 24 in the usual manner. The
upper surface of the adaptor member 28 is shaped to define a dished region 30. A rocker
member 32 is bolted or otherwise rigidly secured to the saddle 16, the rocker member
32 including, on its underside, a projection 34 having a part-spherical surface 36
located, at least in part, within the dished region 30 of the adaptor member 28. The
rocker arrangement 26 thus allows a degree of articulation between the saddle 16 and
the axle 24.
[0012] In accordance with the invention, resiliently deformable components 38 in the form
of blocks of a rubber or rubber-like material are located on opposite sides of the
rocker member 32, the resiliently deformable components being located between the
saddle 16 and the adaptor member 28 and arranged such that in the event of relative
tilting occurring between the saddle 16 and the adaptor member 28, as permitted by
the rocker arrangement 26, at least part of at least one or the other of the components
38 will be compressed, such compression serving to damp the relative tilting motion
and further serving to apply a restoring force urging the saddle 16 and adaptor member
28 towards their original positions. In the arrangement illustrated in the accompanying
drawings, the components 38 are mounted upon respective support plates 40 which are
interconnected by a cross-member 42 so as to adopt an H configuration. However, it
will be appreciated that other configurations may be used, if desired. Further, retainer
members 44 are secured to the saddle 16 in order to securely retain the components
38 in position, in use.
[0013] Although one specific embodiment of the invention has been described herein, it will
be appreciated that the invention may be modified in numerous ways without departing
from the scope of the invention. For example, the rocker member 32 may be modified
to include flanges with which the components 38 engage rather than the components
38 co-operating directly against the saddle 16. It may further be possible to modify
the shape of the components 38, or possible to include, for example, a greater number
of components 38 in the rocker arrangement 26.
1. A rocker arrangement comprising a rocker member and an adaptor member, the rocker
member and the adaptor member having co-operating surfaces arranged to allow the rocker
member to tilt relative to the adaptor member, and at least one resiliently deformable
component arranged to apply a restoring force in the event of tilting of the rocker
member relative to the adaptor member.
2. An arrangement according to Claim 1, wherein the resiliently deformable component
includes first and second deformable elements located on opposing sides of the co-operating
surfaces.
3. An arrangement according to Claim 2, wherein the deformable elements are connected.
4. An arrangement according to Claim 3, wherein the deformable elements are mounted on
a common support plate.
5. An arrangement according to any of Claims 2 to 4, wherein the elements are blocks
of rubber or rubber-like material.
6. An arrangement according to any of the preceding claims, wherein the rocker member
is shaped to define a part-spherical projection arranged to extend into a dished part
of the adaptor member.
7. An arrangement according to any of Claims 2 to 5, further comprising retainer members
to retain the elements in position.