GB2032369A - Stabilisers for railway bogie vehicles - Google Patents

Abstract

A stabiliser for connection between a part of the bogie frame and a part of the vehicle underframe, comprises a friction pad 31 having a linkage 33, 35, for connecting it to one frame part, and carried by a mounting 19 for attachment to the other frame part. A spring 34 urges the pad 31 into frictional engagement with a rubbing plate 10 on the other frame part, the spring 34 being so disposed between the mounting 19 and pad 31 that relative displacement between said frame parts from a datum position, partly relieves the load on the spring; the frictional restraint against rotation of the bogie is thus reduced in dependence on the extent of the relative rotational displacement. <IMAGE>

Description

SPECIFICATION Improvements in stabilisers for railway bogie vehi cles This invention relates to stabilisers for use on railway bogie vehicles and particularly to stabilisers for use as sidebearers which act between the bogie and the vehicle underframe to restrain frictionally relative rotational movement between the underframe and the bogie and thus control "hunting" of the bogie. Two sidebearers are normally employed, being symmetrically disposed one at each side of the bogie centre pivot, although in an alternative arrangement according to the invention only a single stabiliser may be provided between the bogie and the vehicle underframe.

In conventional sidebearers the frictional restraint applied between the bogie and the vehicle underframe remains substantially constant regardless of the extent of the relative displacement between the bogie and the vehicle, such rotational displacement varying according to the curvature of the rails around which the bogie is travelling. It is, however, desirable thatthefrictional restraint should be reduced as the rotational displacement between the bogie and the vehicle underframe increases.Such reduction permits easier adaptation of the position of the bogie with respect to the rails when the bogie is travelling around sharp curves and thus reduces the lateral forces between the wheels and the rails to reduce wear and to reduce the risk of derailment It is accordingly an object of the invention to provide a stabiliser, particularly for use as a sidebearer, in which the frictional restraint against rotation of the bogie provided by the stabiliser is reduced in dependence on the extent of relative rotational displacement.According to the invention a stabiliser for a railway bogie vehicle, for connection between a part of the bogie frame and a part of the vehicle underframe, comprises a friction pad having means for connecting it to one frame part, and spring means arranged to urge the friction pad into frictional engagement with a rubbing plate on the other frame part, said means being so disposed that relative displacement between said frame parts from a datum position partly relieves the load on the spring means thereby reducing the spring force urging the friction pad into engagement with the rubbing plate.

The friction pad may be carried by a mounting for attachment to said other frame part, and may be displaceable relative to said mounting under the action of said spring means, relative displacement between the frame parts causing displacement of the friction pad relative to said mounting in a manner partly to relieve the load on the spring means.

Preferably said mounting has means for pivotally attaching itto said other frame part and said spring means comprise a compression spring acting between the mounting and a member connected to the friction pad, whereby relative displacement between the frame parts causes tilting of the mounting about its pivot and displacement of the friction pad relative to the mounting, thereby partly relieving the compressive load on the spring.

The member connected to the friction pad may comprise a rod slideable in a guide on said mounting, and the compression spring may comprise a helical compression spring encircling said rod.

The friction pad is preferably pivotally connected to said rod so as to remain flatly in engagement with the rubbing plate upon tilting of the mounting.

In a preferred embodiment of the invention the mounting and said rubbing plate are both carried by a unitary structure for mounting on said frame part.

For example the unitary structure may comprise a box-like unit on opposite walls of which are mounted said mounting and rubbing plate respectively, said means for connecting the friction pad to said one frame part comprising a linkage one end of which is pivotally connected to the friction pad, the linkage extending out of the box-like unit and having its opposite end arranged for pivotal attachment to said one frame part.

In an alternative embodiment, the friction pad is carried by a pivot arm having a pivotal mounting for attachment to said one frame part, and there are provided coupling means for connecting the pivot arm to said other frame part, said spring means acting on the pivot arm in a direction to urge the friction pad into engagement with the rubbing plate, and said coupling means being so disposed that relative displacement between said frame parts from a datum position and transversely of the pivot axis of the pivot arm displaces said coupling means in a manner partly to relieve the load on said spring means and thereby reduce the spring force urging the friction pad into engagement with the rubbing plate.

The coupling means and the friction pad may be disposed on opposite sides of the pivot axis of the pivot arm.

The coupling means may comprise a linkage for pivotally connecting the pivot arm to said other frame part, whereby said relative displacement between said frame parts effects pivoting of the linkage to alter the restraint imposed on the pivot arm by said linkage.

The linkage may comprise an extensible link comprising two relatively movable elements urged apart by said spring means, one element being arranged for pivotal connection to said other frame part and the other element being pivotally connected to said pivot arm. The two elements may be in relative sliding engagement with one another.

Alternatively, said pivotal mounting for the pivot arm may be such as to permit movement of the pivot axis of the pivot arm towards and way from said one frame part in dependence on displacement of said coupling means, said spring means acting between said one frame part and the pivot arm so as to be partly relieved by movement of the pivot axis away from said one frame part. In this arrangement also the coupling means may comprise a linkage for pivotally connecting the pivot arm to said other frame part.

The following is a more detailed description of various embodiments of the invention, reference being madetothe accompanying drawings in which: Figure 1 is a longitudinal vertical section through a stabiliser in accordance with the invention, Figure 2 is a vertical transverse cross-section of the stabiliser of Figure 1, Figure 3 is a diagrammatic plan view of a bogie frame showing the manner in which a single stabiliser may be fitted to the bogie frame, Figure 4 is a diagrammatic side elevation of an alternative form of stabiliser in accordance with the invention, Figure 5 is a diagrammatic side elevation of a further form of stabiliser, Figure 6 is a vertical cross-section through the stabiliser of Figure 5, and Figure 7 is a horizontal cross-section through the stabiliser of Figures 5 and 6.

In this specification the term "fore and aft" refers to the normal direction of travel of the rail vehicle, and the term "lateral" refers to a direction transverse to said direction.

Referring to Figures 1 and 2, the stabiliser is in the form of a unitary structure of open-ended box-like form comprising a bottom plate 10 and a top plate 11 connected by vertical side plates 12 welded between the bottom plate 10 and longitudinal reinforcing flanges 13 welded to the underside of the top plate 11 along opposite marginal portions thereof.

The top plate 11 is formed with a central elongated aperture 14 at opposite sides of which are disposed upstanding bearing plates 15 which are welded, at their lower edges, to the top plate 11.

Each bearing plate is formed with a vertically extending slot 16 in which is vertically slideable a block 17. The blocks 17 act as bearings for trunnions 18 which extend laterallyfrom opposite sides of a mounting assembly 19.

The mounting assembly 19 comprises a top plate 20 to which are welded side plates 21 and end plates 22, the trunnions 18 being welded to the side plates 21 respectively. The trunnions permit the mounting assembly 19to pivot relative to the bearing plates 15 about a horizontal transverse axis.

As best seen in Figure 1, a central bearing tube 23 is welded at its upper end in a circular aperture in the top plate 20 of the mounting assembly and extends downwardly so that its lower end is level with the lower edges of the side walls 21 and end walls 22 of the mounting. A rod 24 is vertically slideable within the bearing tube 23 and a screw 25 is threaded into the upper end of the rod 24, a stop washer 26 being disposed between the head of the screw 25 and the end of the rod 24 so as to be engageable with the upper end of the bearing tube 23 and thereby limit the downward movement of the rod 24.

A rectangular plate 27 is welded to the lower end of the rod 24 and laterally spaced bearing lugs 28 are welded to the underside of the plate 27 and extend downwardly therefrom. A pivot pin 29 passes through registering holes in the bearing lugs 28 and an upwardly extending lug 30 disposed between the lugs 28, the lug 30 being welded to the upper side of a friction pad 31. The friction pad 31 has a friction surface 32 on the underside thereof which engages the bottom plate 10 which constitutes a rubbing plate.

A further upstanding lug 33, spaced longitudinally from the lug 30, is also welded to the upper side of the friction pad 31. A link (not shown) is pivotally connected at one end thereof to the lug 33 and extends out of the open end of the box-like structure.

A helical compression spring 34 encircles the bearing tube 23 and rod 24 and bears at its upper end against the underside of the plate 20 of the mounting and at its lower end on the upper side of the plate 27 so as to urge the friction pad 31 into engagement with the rubbing plate 10.

Stabilisers of the kind described may be used in place of conventional sidebearers. In this case the box-like structure may be mounted on the bogie frame in the conventional position for such sidebearers with the trunnions 18 and pivot pin 29 extending transversely of the fore-and-aft direction of movement of the railway vehicle. The link, one end of which is connected to the lug 33 by means of a pivot pin 35, extends out of the end of the box-like structure and has its opposite end pivotally connected to a part of the railway vehicle underframe.

Alternatively, the box-like structure might be fitted to the vehicle underframe and the link connected to the bogie frame.

In either arrangement relative rotational movement between the bogie frame and the vehicle underframe causes relative displacement between the link and the box-like structure causing sliding of the friction pad 31 relative to the box-like structure, the relative rotational movement thereby being restrained by the frictional engagement between the surface 32 and the rubbing plate 10. However, as such relative movementtakes place the mounting assembly 19 tilts on the trunnions 18 and the distance between the axis of the pivot pin 29 and the axis of the trunnions 18 increases. Consequently the rod 24 slides downwardly in the bearing tube 23 as the mounting tilts, thus partly relieving the precompression of the helical spring 34.Consequently the downward pressure exerted on the friction pad 31 by the compression spring 34 decreases, thus reducing the frictional restraint to relative rotational movement offered by the friction pad. This therefore achieves the desired object referred to earlier whereby the frictional restraint reduces with increase of rotational displacement.

The aperture 14 in the top plate 11 is of such a size as to permit free movement of the plate 27 upon tilting of the mounting 20.

The aforementioned link, instead of being pivotally connected to the separate lug 33 welded to the plate 31, might instead be directly connected to the pivot pin 29. In either arrangement there may be provided two links extending out of opposite ends of the box-like structure and pivotally connected to spaced parts of the vehicle underframe or the bogie frame as the case may be.

Figure 3 shows an arrangement where a single central stabiliser is used instead of two stabilisers located at the conventional locations for sidebearers.

In the arrangement of Figure 3 the box-like structure is mounted so as to extend transversely of the centre line of the bogie frame 36. The link 37 also extends transversely of the bogie frame and is pivotally connected at its opposite end to a part of the vehicle underframe. As before, a similar link might also extend from the opposite end of the box-like structure. It will be appreciated that the arrangement might also be modified so that the box-like structure is mounted on the vehicle underframe and the link 37 is connected to the bogie frame.

The described arrangements have the advantage that the stabiliser is in the form of a single unit which may be easily fitted to existing rail vehicles, the setting up of the stabiliser not requiring any accurate adjustment. The only adjustment required is to ensure that the pivotal attachment for the link is a predetermined distance from the location of the box-like structure when the bogie and vehicle underframe are in a predetermined relative position, which will normally be the fore-and-aft position.

In the alternative embodiment shown in Figure 4, a part 110 of the bogie frame or bogie bolster carries a pivotal mounting 111 which supports a pivot arm 112 for pivotal movement about a horizontal pivot pin 113, the axis of which extends laterally of the rail vehicle.

Atone end of the pivot arm 112 a friction pad 114 is mounted on the pivot arm by means of a cylindrical bearing 115, and is in frictional engagement with a rubbing plate 116 mounted on the underside of a part 117 of the vehicle underframe.

The opposite end of the pivot arm 112 is connected to the underframe part 117 by a linkage indicated generally at 118. The linkage comprises a first link element 119 pivotally mounted on the end of the pivot arm 112 by a pivot pin 120, and having an upwardly extending pin 121 which is slideably received in a circular cross-section socket 122 constituting the second link element.

The socket 122 has mounted on the outside thereof two diametrically opposed trunnions 123 which are slideably received in downwardly opening slots 124 formed in laterally spaced guide plates 125 mounted on the vehicle underframe part 117. The arrangement is such that the linkage formed by the link elements 121 and 122 may pivot about the lateral axis 126 of the trunnions 123. A helical compression spring 127 encircles the socket 122 and is disposed between a flange 128 secured to one end of the socket and a flange 129 on the link element 119.

A bolt 130 passes through an aperture in the flange 128 and is in threaded engagement with the pin 121 so that the relative sliding movement between the pin 121 and socket 122 is limited by engagement of the head of the bolt 130 with the exterior surface of the flange 128.

In operation, with the bogie in the datum foreand-aft position, the bolt 130 is adjusted to provide a required clearance between its head and the flange 128 so that the compression of the spring 127 urges the pivot arm 112 in an anti-clockwise direction, and thus urges the friction pad 114 into engagement with the rubbing plate 116. When relative rotation takes place between the bogie frame and the vehicle, as the vehicle traverses a curve, the mounting 111 for the pivot arm 112 will move towards or away from the plates 125 depending on the direction of said rotation. Thus the pivot pin 120 will move in the fore-and-aft direction relative to the trunnions 126.

Since the pivot pin 120 moves substantially horizontally with respect to the vehicle underframe the linkage 118 will extend, the pin 121 sliding out of the socket 122. The flanges 128 and 129 will thus move further apart permitting the spring 127 to extend thereby relieving part of the compressive load on the spring. Consequently the anti-clockwise turning moment applied to the pivot arm 112 by the spring 127 is reduced, in turn reducing the force of engagement between the friction pad 114 and the rubbing plate 116. Accordingly, frictional restraint applied by each stabiliser will be reduced in dependence on the extent of the relative rotational movement between the bogie and the vehicle underframe.

The load applied by the spring will continue to be reduced until the head of the bolt 130 engages the flange 128, whereafter no further extension of the spring 127 is possible and the trunnions 123 will move downwardly in the slot 124 so that no turning moment is applied to the pivot arm 112.

It will be appreciated that a similar stabiliser is symmetrically disposed on the opposite side of the central vertical pivot of the bogie bolster.

Interengaging faces 131 and 132 are formed on the pivot arm 112 and mounting 111 respectively to form a bump stop limiting the clockwise rotation of the pivot arm 112.

To relieve the pivotal mounting of the pivot arm of loads in the fore-and-aft direction, the friction pad may be formed with a downwardly projecting, laterally extending flange (not shown) which is in sliding engagement between spaced laterally extending flanges projecting upwardly from a part of the bogie frame or bolster.

In the alternative arrangement shown in Figures 5 to 7 the pivot arm 133 is pivotally supported on a mounting 134 carried by the vehicle underframe 135 and has a friction pad 136 engaging a rubbing plate 137 on a part 138 of the bogie frame or bolster.

lnthisarrnngementthe mounting 134 comprises laterally spaced plates 139 (only one of which is shown in Figures 6 and 7) having downwardlyopening slots 140. Blocks 141 are slideable up and down in the slots 139 and are formed with inwardly projecting trunnions 142 on which the pivot arm, which is U-shaped in cross-section, is pivotally mounted so as to pivot about a lateral axis 143. A helical compression spring 144 acts between the lower web portion 145 of the pivot arm 133 and the vehicle underframe part 135 so as to urge the pivot arm 133, and hence its pivot axis, downwardly. A bolt 145 extends upwardly through an aperture in the web portion 145 and threadably engages a block 147 mounted on the vehicle underframe, the bolt serving to limit the downward movement of the pivot arm 133.

At the end of the pivot arm 133 remote from the friction pad 136 there is mounted a transverse pin 148 which is slideable in an elongated slot 149 in a link 150 which is pivotally mounted, by means of a further pin 150, on a mounting 152 on the part 138 of the bogie frame or bolster During operation of the sideframe shown in Fig ures 5 to 7, the pin 148 is normally disposed at the lower end of the slot 149, as shown, and the com pression spring 144 urges the pivot arm 133 downwardly so as to urge the friction pad 136 into engagement with the rubbing plate 137. When relative rotation takes place between the bogie and the vehicle underframe the pivot pin 151 moves to the right orto the left with respect to the pivot axis 143 of the pivot arm, and the link 150 swings through an arc aboutthe pivot pin 151. Consequently the lower end of the slot 149 is swung closer to the bogie part 138 permitting further downward movement of the pivot arm 133 under the action of the compression spring 144. This downward movement of the pivot arm is accompanied by extension of the spring 144 so that the force exerted by the spring on the pivot arm is reduced, hence reducing also the force urging the friction pad 136 into engagement with the rubbing plate 137. Consequently in this arrangement also the friction restraint exerted by the stabilisers will be reduced in dependence on the extent of relative rotation between the bogie and the vehicle.

It will be appreciated that any of the above described arrangements will operate in a similar manner if inverted, that is to say if the parts connected to the vehicle underframe are connected to the bogie and vice versa.

Claims (16)

1. A stabiliser for a railway bogie vehicle, for connection between a part of the bogie frame and a part of the vehicle underframe, comprising a friction pad having means for connecting itto one frame part, and spring means arranged to urge the friction pad into frictional engagement with a rubbing plate on the other frame part, said means being so disposed that relative displacement between said frame parts from a datum position partly relieves the load on the spring means thereby reducing the spring force urging the friction pad into engagement with the rubbing plate.

2. A stabiliser according to claim 1, wherein the friction pad is carried by a mounting for attachment to said other frame part, and is displaceable relative to said mounting under the action of said spring means, relative displacement between the frame parts causing displacement of the friction pad rela tire to said mounting in a manner partly to relieve the load on the spring means.

3. A stabiliser according to claim 2, wherein said mounting has means for pivotally attaching itto said other frame part and said spring means comprise a compression spring acting between the mounting and a member connected to the friction pad, whereby relative displacement between the frame parts causes tilting of the mounting about its pivot and displacement of the friction pad relative to the mounting, thereby partly relieving the compressive load on the spring.

4. A stabiliser according to claim 3, wherein the member connected to the friction pad comprises a rod slideable in a guide on said mounting, and the compression spring comprises a helical compression spring encircling said rod.

5. A stabiliser according to claim 4, wherein the friction pad is pivotally connected to said rod so as to remain flatly in engagement with the rubbing plate upon tilting of the mounting.

6. A stabiliser according to any of claims 1 to 5, wherein the mounting and said rubbing plate are both carried by a unitary structure for mounting on said frame part.

7. A stabiliser according to claim 6, wherein the unitary structure comprises a box-like unit on opposite walls of which are mounted said mounting and rubbing plate respectively, said means for connecting the friction pad to said one frame part comprising a linkage one end of which is pivotally connected to the friction pad, the linkage extending out of the box-like unit and having its opposite end arranged for pivotal attachment to said one frame part.

8. A stabiliser according to claim 1, wherein the friction pad is carried by a pivot arm having a pivotal mounting for attachment to said one frame part, and wherein there are provided coupling means for connecting the pivot arm to said other frame part, said spring means acting on the pivot arm in a direction to urge the friction pad into engagement with the rubbing plate, and said coupling means being so disposed that relative displacement between said frame parts from a datum position and transversely of the pivot axis of the pivot arm displaces said coupling means in a manner partly to relieve the load on said spring means and thereby reduce the spring force urging the friction pad into engagement with the rubbing plate.

9. A stabiliser according to claim 8, wherein the coupling means and the friction pad are disposed on opposite sides of the pivot axis of the pivot arm.

10. A stabiliser according to claim 8 or claim 9, wherein the coupling means comprise a linkage for pivotally connecting the pivot arm to said other frame part, whereby said relative displacement between said frame parts effects pivoting of the linkage to alterthe restraint imposed on the pivot arm by said linkage.

11. Astabiliser according to claim 10, wherein the linkage comprises an extensible link comprising two relatively movable elements urged apart by said spring means, one element being arranged for pivotal connection to said other frame part and the other element being pivotally connected to said pivot arm.

12. A stabiliser according to claim 11,wherein the two elements are in relative sliding engagement with one another.

13. A stabiliser according to claim 8, wherein said pivotal mounting for the pivot arm is such as to permit movement of the pivot axis of the pivot arm towards and away from said one frame part in dependence on displacement of said coupling means, said spring means acting between said one frame part and the pivot arm so as to be partly relieved by movement of the pivot axis away from said one frame part.

14. A stabiliser according to claim 13, wherein the coupling means comprises a linkage for pivotally connecting the pivot arm to said other frame part.

15. A stabiliser, for a railway bogie vehicle, sub stantially as hereinbefore described with reference to Figures 1 and 2, or Figure 4, or Figure 5 of the accompanying drawings.

16. A railway vehicle comprising one or more stabilisers according to any of the preceding claims connected between a part of the bogie frame and a part of the vehicle underframe.