GB1571499A - Railway vehicles and bogies - Google Patents

Description

(54) IMPROVEMENTS RELATING TO RAILWAY VEHICLES AND BOGIES (71) We, BRITISH RAILWAYS BOARD, a public authority established under the provisions of the Transport Act 1962, of 222 Marylebone Road, London, N.W.1., do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to railway vehicles and to bogies for railway vehicles.

The invention is concerned with the development of the invention described and claimed in our British Patent Specification No. 1179723.

According to the invention described and claimed in our British Patent Specification No. 1179723, in a railway vehicle or bogie having at least two wheelsets, each with a live axle mounted at each of its ends in a respective axle bearing, at least one axle bearing of one wheelset is elastically interconnected with at least one axle bearing of the other wheelset through bracing means which serve no vertical load carrying function at least intermediate their connections to the axle bearings, said bracing means providing bracing between the wheelsets which produces restoring forces to relative displacements of the wheelsets from their parallel and aligned position, and the vehicle body is supported or is adapted to be supported. on the wheelsets in the case of a non-bogie vehicle, or on the bogie, in a manner offering substantially no restraint to horizontal rotation of the vehicle body relative to the wheelsets.

In one specific configuration described in our Patent Specification No. 1179723, elastic bracing means extend both diagonally and longitudinally between the wheelsets.

Thus in the case of diagonal bracing, elastic bracing means extend from one axle bearing of one wheelset to the diagonally opposite axle bearing of the other wheelset, and in the case of the longitudinal bracing, elastic bracing means extend from one axle bearing of one wheelset to the axle bearing on the same side of the vehicle or bogie of the other wheelset.

According to one aspect of the present invention in a railway vehicle as defined in claim 1, or in a bogie as defined in claim 2 of our Patent Specification No. 1179723, diagonal elastic bracing means is provided in combination with non-elastic longitudinal bracing means extending between the wheelsets, said longitudinal bracing means incorporating damping means in its length.

Such an arrangement permits restrained variation in the length of said longitudinal bracing means when said wheelsets move relatively to each other.

In our Patent Specification No. 1179723 the possibility of incorporating a viscous or hydraulic damper in series with elastic means, in the length of the bracing means is proposed but no specific configuration using this feature is described.

According to another aspect of the present invention diagonal elastic bracing means is provided in combination with longitudinal bracing means extending between the wheelsets, the bracing means incorporating damping means and elastic means in series in its length. In further development of this configuration further elastic means, for example in the form of a spring, may be arranged in parallel with the series connected damping and elastic means, this further elastic means being normally of lower stiffness than the first mentioned elastic means.

The mechanical implementation of the bracing means may be generally as described in our Patent Specification No.

1179723. Thus it may take the form of a strut with resilient material and/or damping means as appropriate in the length of the strut. Alternatively the elastic means may take the form of a fluid spring.

The invention will now be further described by way of example with reference to the accompanying drawings, in which Figures 1 to 3 show different embodiments of the invention.

In the embodiment of Figure 1 wheelsets Wl and W2 of a bogie or of a non-bogie type vehicle are interconnected by diagonal elastic bracing means l and 2 in accordance with the principles set out in British Patent Specification No. 1179723. In addition nonelastic longitudinal bracing is provided between the wheelsets and comprises struts 3 and 4 containing viscous or hydraulic dampers 5 in their lengths. In accordance with the arrangement described in British Patent Specification No. 1179723, the longitudinal and diagonal bracing means are connected to the axle bearings of the wheelsets.

In the embodiment Figure 2 wheelsets W1 and W2 are again inter-connected by diagonal elastic bracing means 1 and 2. In this embodiment however longitudinal bracing is provided by struts 3 and 4 having dampers 5 and springs 6 in series contained within their lengths.

The Figure 3 embodiment is similar to the Figure 2 embodiment except that additional springs 7 are connected in parallel with the series connected dampers 5 and springs 6 in the longitudinal bracing.

With the damper and spring combinations of Figures 2 and 3, it can be arranged by appropriate choice of spring stiffness and damper characteristics to permit substantially unrestrained low velocity yawings of the wheelsets relative to each other, such as are encountered when the vehicle negotiates a curve in the track so that the wheelsets remain substantially radially aligned to track curvature. On the other hand. there is provided an appropriate dynamic stiffness to ensure dynamic stability, as if such dynamic stability is absent high velocity yawing in the nature of high frequency oscillations may occur.

WHAT WE CLAIM IS: 1. A railway vehicle according to claim 1 or a bogie according to claim 2 of Patent No.

1179723, wherein diagonal elastic bracing means in combination with longitudinal non-elastic bracing means extend between the wheelsets, said longitudinal bracing means incorporating damping means in its length.

2. A railway vehicle or bogie according to claim 1, wherein said diagonal bracing means extend between each axle bearing of one wheelset and the diagonally opposite axle bearing of the other wheelset and said longitudinal bracing means extend between each axle bearing of one wheelset and the axle bearing of the other wheelset on the same side of the vehicle or bogie.

3. A railway vehicle according to claim 1 or a bogie according to claim 2 of Patent No.

1179723, wherein diagonal elastic bracing means in combination with longitudinal bracing means extend between the wheelsets, said longitudinal bracing means incorporating damping means and elastic means in series in its length.

4. A railway vehicle or bogie according to claims 3, wherein further elastic means is arranged in parallel with the series connected damping and elastic means.

5. A railway vehicle or bogie according to claim 4, wherein said further elastic means is of lower stiffness than the first mentioned elastic means.

6. A railway vehicle or bogie according to any one of claims 3 to 5, wherein said diagonal bracing means extend between each axle bearing of one wheelset and the diagonally opposite axle bearing of the other wheelset and said longitudinal bracing means extend between each axle bearing of one wheelset and the axle bearing of the other wheelset on the same side of the vehicle or bogie.

7. A railway vehicle or bogie substantially as hereinbefore described with reference to Figure 1 or Figure 2 or Figure 3 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. take the form of a fluid spring. The invention will now be further described by way of example with reference to the accompanying drawings, in which Figures 1 to 3 show different embodiments of the invention. In the embodiment of Figure 1 wheelsets Wl and W2 of a bogie or of a non-bogie type vehicle are interconnected by diagonal elastic bracing means l and 2 in accordance with the principles set out in British Patent Specification No. 1179723. In addition nonelastic longitudinal bracing is provided between the wheelsets and comprises struts 3 and 4 containing viscous or hydraulic dampers 5 in their lengths. In accordance with the arrangement described in British Patent Specification No. 1179723, the longitudinal and diagonal bracing means are connected to the axle bearings of the wheelsets. In the embodiment Figure 2 wheelsets W1 and W2 are again inter-connected by diagonal elastic bracing means 1 and 2. In this embodiment however longitudinal bracing is provided by struts 3 and 4 having dampers 5 and springs 6 in series contained within their lengths. The Figure 3 embodiment is similar to the Figure 2 embodiment except that additional springs 7 are connected in parallel with the series connected dampers 5 and springs 6 in the longitudinal bracing. With the damper and spring combinations of Figures 2 and 3, it can be arranged by appropriate choice of spring stiffness and damper characteristics to permit substantially unrestrained low velocity yawings of the wheelsets relative to each other, such as are encountered when the vehicle negotiates a curve in the track so that the wheelsets remain substantially radially aligned to track curvature. On the other hand. there is provided an appropriate dynamic stiffness to ensure dynamic stability, as if such dynamic stability is absent high velocity yawing in the nature of high frequency oscillations may occur. WHAT WE CLAIM IS:

1. A railway vehicle according to claim 1 or a bogie according to claim 2 of Patent No.

1179723, wherein diagonal elastic bracing means in combination with longitudinal non-elastic bracing means extend between the wheelsets, said longitudinal bracing means incorporating damping means in its length.

2. A railway vehicle or bogie according to claim 1, wherein said diagonal bracing means extend between each axle bearing of one wheelset and the diagonally opposite axle bearing of the other wheelset and said longitudinal bracing means extend between each axle bearing of one wheelset and the axle bearing of the other wheelset on the same side of the vehicle or bogie.

3. A railway vehicle according to claim 1 or a bogie according to claim 2 of Patent No.

1179723, wherein diagonal elastic bracing means in combination with longitudinal bracing means extend between the wheelsets, said longitudinal bracing means incorporating damping means and elastic means in series in its length.

4. A railway vehicle or bogie according to claims 3, wherein further elastic means is arranged in parallel with the series connected damping and elastic means.

5. A railway vehicle or bogie according to claim 4, wherein said further elastic means is of lower stiffness than the first mentioned elastic means.

6. A railway vehicle or bogie according to any one of claims 3 to 5, wherein said diagonal bracing means extend between each axle bearing of one wheelset and the diagonally opposite axle bearing of the other wheelset and said longitudinal bracing means extend between each axle bearing of one wheelset and the axle bearing of the other wheelset on the same side of the vehicle or bogie.

7. A railway vehicle or bogie substantially as hereinbefore described with reference to Figure 1 or Figure 2 or Figure 3 of the accompanying drawings.