GB2168663A - Rail vehicle bogie brake arrangement - Google Patents

Abstract

A railway vehicle bogie (1) has a bogie frame (2) which has been manufactured in one-piece, e.g. by casting or machining from solid plate. The bogie may include bearings (15) mounted inboard of the wheels (4) as compared to the conventional bogies in which the bearings are outboard of the wheels. The use of a one-piece frame is particularly advantageous for bogies having comparatively small wheel diameters e.g. 300 to 650 mm.

Description

SPECIFICATION Improvements relating to railway vehicles The present invention relates to railway vehicles.

Railway vehicles for operation on any particular railway railway system must obviously be designed such that in the loaded or unloaded condition they will pass under or through all bridges or tunnels on the system with a minimum margin of safety between the vehicle or its load and the bridge or tunnel.

Similarly, the vehicles must be able to travel around curves without 'overhanging' to a degree which would cause danger to railway vehicles on adjacent tracks.

To meet these requirements, freight carrying railway vehicles in the U.K. must be designed in accordance with the W5 gauge and the concessions associated therewith. Other countries also have their own gauge requirements.

There is currently a desire to increase the load carrying capacity of railway vehicles. For example, in the case of containers which may be transported by railway vehicles the current maximum height of such containers is about 8'6". When such containers are loaded on the railway vehicles they are still generally within the concession to W5 gauge. However various European countries now use containers of about 9'0" in height whereas containers available in the U.S.A. may be as high as 9'6".

Such containers, (which may of course be imported into the U.K.) when loaded on currently available rail vehicles, do not lie within W5 gauge and cannot therefore be transported by rail.

In order to increase the load carrying capacities of railway vehicles, whilst still conforming to the gauge requirements, it is necessary to construct a vehicle whereof the load carrying chassis is of lower height than in conventional railway vehicles and this necessitate that smaller diameter wheels be used so as not to interfere with the chassis.

However, a simple reduction in the size of the conventionally used wheels does not provide a satisfactory vehicle since there are attendent problems associated with the use of smaller diameter wheels, particularly problems relating to positioning of brake equipment for the vehicle.

According to a first aspect of the present invention there is provided a railway vehicle designed in accordance with W5 gauge and having a braking mechanism at least a part of which locates at least partly below W5 gauge.

According to a second aspect of the present invention there is provided a railway vehicle bogie designed in accordance with W5 gauge comprising a bogie frame adapted to be pivotally mounted relative to the chassis of the vehicle and having two wheel and axle units, wherein the bogie has a braking mechanism at least a part of which locates at least partly below W5 gauge.

As used herein, the expression 'at least partly below W5 gauge' refers to that space of W5 gauge which is allowed for wheel travel and which is permissible subject to no overthrow.

In accordance with the invention, it is in the gross condition of the vehicle or bogie that the part of the brake mechanism locates below W5 gauge. This part of the braking mechanism may also locate below W5 gauge in the tare condition of the vehicle or bogies.

The part of the braking mechanism which locates below W5 gauge may for example be, part of a brake lever, brake block, brake pad, and/or brake actuator.

The vehicle or bogie is preferably braked by a tread brake assembly. the braking mechanism of the tread brake assembly preferably incorporates a prime actuator and it is at least this actuator which locates at least partly below W5 gauge. The tread brake assembly preferably comprises two tread brakes each arranged for application to one of two adjacent wheels on the same side of the vehicle or bogie and the prime actuator is operatively associated with both said brakes to apply them against the respective wheels during brake application.

The or each tread brake may be mounted on substantially vertical, pivotal brake levers.

The brake mechanism of the vehicle or bogie of the invention, thus occupies space which is not normally utilised. The invention has particular advantage in the case of railway vehicles or bogies with small wheels (e.g. 300 to 650mm) since, in such vehicles or bogies there may be too little space to incorporate brake assemblies in conventionally used positions.

The invention will be further described, by way of example only, with reference to the accompanying drawings, in which: Fig. 1 illustrates W5 gauge; and Fig. 2 illustrates one embodiment of railway vehicle bogie in accordance with the invention.

W5 gaue is illustrated in Fig. 1. The level 1 of the gauge is 152mm (6") above rail level 2 (the rails being designated by reference numerals 3)., The space allowed for the wheels is defined by the two pairs of vertical lines 4, 4' which extend upwards from rail level 2 to a position above level 1.

In accordance with the invention it is proposed that a prime actuator 5 for the brakes of the vehicle be located in the path of wheel travel and (when viewed in a section transverse of the wagon) at least partly in the rectangle defined by the level 1, rail level 2 and a pair of lines 4, 4'. This rectangle represents space on W5 gauge which is permissible subject to no overthrow.

The location of the prime actuator in such a position utilises a space on the vehilcle which is available within the constraints of W5 gauge. Such positioning of the prime actuator is particularly advantageous in the case of vehicles having a comparatively small wheel diameter (e.g. 300-650mm) since there may only be very limited space available on such vehicles in those locations in which the actuator is normally positioned.

One embodiment of railway bogie in accordance with the invention is shown in Fig. 2.

The illustrated bogie unit 6 comprises a onepiece bogie frame 7 and two spaced wheel and axle units 8 with the wheels 9 of each such unit being of comparatively small diameter (e.g. 300mm) as compared to conventional sized railway wheels.

An in-line pusher brake assembly is provided for the bogie and comprises two brake arms 10 (each associated with a brake block unit 11) provided on adjacent sides of the wheels 9 and a brake cylinder 12, the actuator of which causes application of the brakes.

More particularly it will be seen that each brake arm 10 is pivotally mounted at its upper end on the frame 7 at its lower end on the brake cylinder 12 is supplied and exhausted along lines 13.

The bogie unit 6 also includes an additional brake arm 14 and associated brake block unit 15 which form part of a hand-brake assembly.

The positioning of cylinder 12 should be noted since in accordance with the invention it lies partly below level 1 of W5 gauge.

Claims (12)

1. A railway vehicle designed in accordance with W5 gauge and having a braking mechanism at least a part of which locates at least partly below W5 gauge.

2. A vehicle as claimed in claim 1 which is braked by a tread brake assembly.

3. A vehicle as claimed in claim 2 wherein the braking mechanism of the tread brake assembly incorporates fluid pressure actuated means operatively associated with the tread brake for applying the brake to the wheel tread wherein the fluid pressure actuated means locates at least partly below W5 gauge.

4. A vehicle as claimed in claim 3 wherein the brake assembly comprises two tread brakes each arranged for application to one of two adjacent wheels on the same side of the vehicle, and said fluid pressure actuated means is operatively associated with both said brakes to apply them against the respective wheels during application of the brakes.

5. A vehicle as claimed in claim 3 or 4 wherein the or each tread brake is mounted on a substantially vertical, pivotally mounted brake arm.

6. A vehicle as claimed in any one of claims 1 to 5 having a wheel diameter of 300 to 650mm.

7. A railway vehicle bogie designed in accordance with W5 gauge comprising a bogie frame adapted to be pivotally mounted relative to the chassis of the vehicle and having two wheel and axle units, wherein the bogie has a braking mechanism at least a part of which locates at least partly below W5 gauge.

8. A bogie as claimed in claim 7 which is braked by a tread brake assembly.

9. A bogie as claimed in claim 8 wherein the braking mechanism of the tread brake assembly incorporates fluid pressure actuated means operatively associated with the tread brake for applying the brake to the wheel tread wherein the fluid pressure actuated means locate at least partly below W5 gauge.

10. A bogie as claimed in claim 5 wherein the tread brake assembly comprises two tread brakes each arranged for application to one of two adjacent wheels on the same side of the bogie, and said fluid pressure actuated means is operatively associated with both said brakes to apply them against the respective wheels during application of the brakes.

11. A bogie as claimed in claim 9 or 10 wherein the or each tread brake is mounted on a substantially vertical pivotally mounted brake arm.

12. A bogie as claimed in any one of claims 7 to 11 having a wheel size of 300 to 650mm.