This invention relates to railway vehicles, whether designed for passengers, freight or a combination of both, and has been devised particularly, but not solely, for use in lightweight or relatively lightweight rail vehicles.

Disclosure of the Invention

It is an object of at least preferred forms of the present invention to provide a braking system for a vehicle which is adapted for use on a rail or rails, preferably a light rail vehicle, a suspension and/or steering system for a vehicle which is adapted for use on a rail or rails, preferably a light rail vehicle and means to give an indication of the loading of a vehicle which is adapted for use on a rail or rails preferably a light rail vehicle which will at least provide the public with a useful choice.

Accordingly in a first aspect the present invention may broadly be said to consist in: a vehicle adapted for use on a rail or rails, said vehicle incorporating friction means arranged so as to come into contact with said rail or rails, when said vehicle is lowered relative to said rail or rails; means to permit or allow the said vehicle to be lowered with respect to said rail or rails when it is desired to decelerate or stop said vehicle.

Preferably the means to permit the vehicle to be lowered with respect to said rail or rails comprises a pressurised suspension system, including a source of fluid or gas under pressure and control means operable to reduce the pressure of said pressurised suspension system thereby causing the lowering of said vehicle.

Preferably said friction means includes or comprises a cutting device.

Preferably said cutting device removes material from the rail or rails.

Preferably said means allowing said vehicle to be lowered can be selectively engaged so as to permit the lowering of the trailing edge of the said vehicle before permitting the lowering of the leading edge of said vehicle.

Preferably the said shoe for mounting the friction means, should include a magnet or magnets, to augment the downforce on the friction means, by magnetic attraction to the rail, to more than the mass of the vehicle due to gravity.

Preferably said magnets are powered by coils switched to the vehicle electrics, but may consist of, or incorporate permanent magnets.

Preferably the engagement of said lowering means will also cause the engagement of an appropriate system in said vehicle so as to reverse the direction of travel of said vehicle or said vehicles wheels.

Preferably the engagement of said system to reverse the direction of travel will automatically raise the vehicle via the means allowing said vehicle to be lowered after motion in the first direction, that is non-reversed direction, of said vehicle has substantially ceased.

Preferably the vehicle is a carriage or a motor unit in a train.

In another aspect the present invention may broadly be said to consist in a braking system for a vehicle adapted to use on a rail or rails; said system comprising:

friction means arranged so as to come into contact with the said rail or rails when said vehicle is lowered relative to said rail or rails.

Preferably said braking system also includes means to permit or allow said vehicle to be lowered when it is desired to decelerate or stop said vehicle.

Preferably the means to permit the vehicle to be lowered comprises a pressurised suspension system, including a source of fluid or gas under pressure and control means operable to reduce the pressure of said pressurised suspension system thereby causing the lowering of said vehicle.

Preferably said friction means includes or comprises a cutting tool.

Preferably said cutting tool removes material from said rail or rails.

Preferably the downforce on the friction means to the rails should be augmented by magnets.

Preferably said means allowing said vehicle to be lowered can be selectively engaged so as to permit the lowering of the trailing edge of said vehicle before permitting the lowering of the leading edge of said vehicle.

Preferably the engagement of said means allowing said vehicle to be lowered also causes the engagement of an appropriate system in a said vehicle to reverse the direction of travel of said vehicle.

Preferably the engagement of said appropriate system to reverse the direction of travel of said vehicle will automatically raise the vehicle after motion in the first direction, that is non-reversed, has substantially ceased.

Preferably the vehicle is a carriage or motor unit in a train.

Accordingly in yet another aspect the present invention may broadly be said to consist in a method of decelerating or stopping a vehicle adapted for use on a rail or rails, said method comprising: providing friction means attached to said vehicle, arranged so as to come into contact with said rail or rails when said vehicle is lowered relative to said rail or rails: and lowering said vehicle when it is desired to decelerate or stop said vehicle so as said friction means comes into contact with said rail or rails.

Preferably there are present means to permit said vehicle to be lowered comprising a pressurised suspension system, including: a source of fluid or gas under pressure and control means operable to reduce the pressure of said pressurised suspension system, thereby causing the lowering of said vehicle.

Preferably said friction means includes or comprises a cutting device.

Preferably said cutting device removes material from said rail or rails.

Preferably said means to permit said vehicle to be lowered can be selectively engaged so as to permit first the lowering of the trailing edge of said vehicle before permitting the lowering of the leading edge of said vehicle.

Preferably the engagement of said lowering means will also cause the engagement of an appropriate system in said vehicle to reverse the driven direction of travel of said vehicle.

Preferably the arrangement of said system to reverse the driven direction of travel will automatically raise the vehicle after motion in the first direction, that is non-reversed direction, has substantially ceased.

Preferably the vehicle is a carriage or motor unit in a train.

In yet another aspect the present invention consists in a vehicle comprising a first unit having linked thereto by flexible linking means, a second unit, said first and second units having attached therebetween a wheel or wheels; wherein said wheels are pivotably attached to both said first and second units such that when said vehicle is cornering or said first and second units are otherwise displaced relative to each other, the angle between said first and second unit is bisected by a nominal line passing through the axle of said wheel or wheels.

Preferably said vehicle includes multiple articulations where the associated wheel set is referenced directly or indirectly to the adjacent body angle.

Preferably both said first and second units are rail vehicles.

Preferably said wheel or wheels are pivotably linked to both said first and second units in two locations, said locations being approximately equally spaced on either side of a notional centre line passing through the approximate transverse centre of said first and second units.

Preferably this body angle reference is used to stabilise the steering of the leading and trailing wheelsets, preferably via hydraulic cylinders.

Preferably the wheelsets are swivelled to the suspension, referenced to the rails, but traditional bogies or fixed axles that are centrally pivoted, can be used.

Preferably the units will be equally bidirectional in operation.

Preferably the leading and trailing wheelsets will have their critical angles corrected with direction of travel.

Preferably these critical angles should include toe in, to combat the basically unstable inherent toe out of tapered rail tyres.

Preferably these critical angles should include a castor angle, to improve the self steering stability.

In another aspect the present invention may broadly be said to consist in a method of linking a wheel or wheels to a vehicle, preferably a lightweight rail vehicle, said vehicle being of the type having a first and second unit attached pivotably to each other, said method comprising: pivotably linking said wheel or wheels to both said first and second units.

Preferably said wheel or wheels comprise two wheels linked by an axle.

Preferably said linking to said first and second unit is via the said axle.

Preferably two links between both the first unit and the axle and the second unit and the axle are provided, said links being spaced approximately equidistantly from a notional transverse centre line through the first and second units.

Preferably said vehicle comprises a train or other vehicle riding on rails.

Preferably said first and second units comprise rail carriages or vehicles.

Another aspect of the invention is to detect the electrical track signalling current between the insulated wheels, to provide a onboard indication that no other train is on the same section of trac, causing a absence of track signalling current between the rails.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.

The invention consists in the foregoing and also envisages constructions of which the following gives examples.

Brief Description of the Drawings

Preferred forms of the present invention will now be described with reference to the accompanying drawings in which;

Figure 1 shows a side elevation of a rail vehicle 1, said rail vehicle preferably comprising a double unit, that is, a first unit 3 and a second unit 4, obviously additional units could be added to the first unit 3 and/or the second unit 4, the rail vehicle 5 includes a single centre wheel set 2, this wheel set 2 is mounted between the units 3 and 4 and is preferably a single axle but could comprise a bogie, power is preferably supplied to the central axle 2, the power is preferably diesel but other means, for example, electric are envisaged;

Figures 2 A, 2B, 2C and 2D show side by side comparisons of a conventional rail vehicle or vehicles shown in Figures 2A and 2C, and rail vehicles according to at least a preferred form of the present invention 1 as shown in Figures 2B and 2C, for comparison the vehicles are shown travelling through a tunnel 5, in Figure 2D the rail vehicle 1 according to a preferred form of the invention is shown travelling through a tunnel 5 which is substantially smaller than those required by conventional rail vehicles;

Figures 3 A and 3B show a partial diagrammatic view of the rail vehicle according to at least a preferred form of the present invention, the figures show the portion of the units 3 and 4 immediately adjacent the centre wheel 2, the centre wheel is shown linked to the first unit 3 and second unit 4 by means of linkages 6 and 7, in preferred forms of the invention the linkages 6 and 7 are made up of sub-linkages, for example, as shown linkages 8 and 9 make up linkage 7 and sub-linkages 10 and 11 make up linkage 6, Figure 3B illustrates the rail vehicle 1 cornering or in any other position wherein said first unit 3 is at an angle relative to said second unit 4, the linkages 6 and 7 position said wheel set 2 such that a line through the axle of the wheel set 2 approximately bisects the angle between the railcars, the wheel set 2 is preferably powered by a motor 12 by means of a drive 14 when the rail vehicle 1 is cornering as illustrated in Figure 3B the drive 14 is offset by an amount indicated by 13 in the figures, therefore the drive is required to be flexible by, for example, means of universal joint;

Figure 4 shows a diagrammatic view showing a rail vehicle cornering, it illustrates the problem of linking any central wheel set 2 with end wheel sets, it is believed in preferred forms of the present invention, at least in part, overcome this problem;

Figure 5 shows another aspect of a preferred form of the present invention as being means to decelerate or stop a rail vehicle 1 , the means comprise friction means 20, said friction means 20 preferably including a cutting device 21 in use said friction means 20 is lowered so as to contact the rails thus decelerating the vehicle, in preferred forms of the invention, the friction means 20 is rigidly attached to the rail vehicle 1 and the lowering is achieved by lowering the suspension of the rail vehicle 1 ;

Figure 6 shows a partial sectional view of wheel assembly, 25 represents a narrow gauge wheel and 26 represents a broad gauge, the figures show the use of the wheel assemblies 25 and 26 to function as an electrical contact to the rail so as to operate a rail control signalling system, the system utilises a detection coil to detect the loss of a rail

signal or a potential voltage applied across the two rail tracks, this is indicative of another train being present on the same section of the track, the figures include the following: an elastomer isolation device 27, a tyre 28, the wheel mounting centre 29, the brake drum or disc and hub 30, the signalling pickup brush 31, the insulated slipring 32, the bonding of the slipring and tyre 32, the signalling current coil 33 and the electronic warning unit 34;

Figures 7A, 7B, 7C, 7D and 7E illustrate the principles of castor tilt, the toeing in of the railcar wheels and the cross-linking of various wheels;

Figure 7A shows a front view of a front wheel drive axle showing the castor tilt;

Figure 7B shows castor tilt with the direction of vehicle travel, 47 could in other forms of the invention be the outer end of the lower suspension of the vehicle, with the latch providing an offset to a normal top arm, in other forms of the invention the cylinder could lie across the top arm driving an eccentric mounted top ball joint;

Figure 7C shows an enlarged view of the pump 44 which is driven off the wheel axle, Figure 7C also shows one form of the axle tilt mechanism;

Figure 7D shows the use of the castor tilt angle to give a toeing in of the wheels in both directions;

Figure 7E shows the cross-linking from the firmly referenced centre axle which in the figure is a trolley-type, to the outer axle via a loss element in preferred forms of the invention comprising a spring to a damped steering arm, the figures show a steering pivot centre line 40, suspension arms 41, a detachable wheel 42, a gear pump in axle banjo 43, a pump driven off the axle 44, a double acting tilt cylinder 45, positioning latch and arm 46, a chassis reference 47, a relief pickup or dump valve 48, a steering arm 49, a steering idler 50, a tie rod 51, a damper 52, a drive cylinder across the body joint 53, a drive cylinder to a steering arm via a lossy element 54 and hydraulic lines 55;

Figure 8 shows a preferred form of the invention wherein the occupancy of each unit 3 or 4 is measured passively, the figures illustrate a means to detect a kick given to the suspension by a entering or exiting passenger, in forms of the invention this may comprise a magnet in a coil 60, height control means for an air bag suspension 61, a height valve 62, the air bag 63, an electronic weight and/or count package which operates when stationary 64, an air bag pressure transducer 65, a detachable wheel 66, the lower suspension arm 67, the display on the side of the vehicles 100;

Figure 9 shows a variation of the form of the invention as shown in Figure 3 wherein the powered centre axle 2 is mounted on one of the units, in this case 3, a link to the other unit 101 provides for the steering of the wheel 2;

Figures 10 A, B, C and D illustrate various alternatives and preferred forms of the present invention, Figure 10 A shows a front or rear axle assembly 100 showing the lower suspension arm 101, said lower suspension arm 101 having lateral freedom of movement, also shown is the steering arm 102 which is referenced to the lower suspension arms by hydraulic dampness; the chassis 2 lower suspension arms swivel 103 is also illustrated as is the portion fixed to the chassis cross member 104; also present in preferred forms of the present invention is an insulated tyre or wheel 105 said tyre 105 is insulated by elastomer rings 106 electrically connecting is a signalling electrical brush 108 which finishes in the terminal 107;

Figure 10 shows an end view of the axle shown in Figure 10B;

Figure 10 C shows a view of a mid axle assembly; and

Figure 10 D shows the end view of a mid axle assembly showing the trailer anti- roll bar 110 which is mounted to the trailer unit 11 1, the axle has a swivel centre at 112 and the position of the inter-unit coupling swivel centre is indicated by Figure 113, the motorised unit anti-roll bar is indicated by the numeral 114 and at the position 115 the unit is mounted to the motorised unit.

Detailed Description of the Invention

As shown in the figures, one aspect of the invention, that is the form relating to a braking system, is preferably put into effect by attaching friction means 20 in the form of outriggers. The friction means 20 may comprise friction pads or in preferred forms of the invention rail cutting devices. The friction means 20 are held a small distance above the rails, eg. 25mm. In an emergency situation or in other situations in which rapid deceleration is desired or required, the suspension of the rail vehicle is modified so that the vehicle is lowered until the friction means 20 come into contact with the rails. In preferred embodiments of the present invention the suspension system is a hydraulic system with a manually operable electrical or electronic bleed valve which is operable to de-pressurise the suspension thereby lowering the vehicle.

In preferred embodiments the pressure in the system can be reduced to a stage where the whole weight of the vehicle is effectively borne by the friction means 20 resting on the rails.

In forms of the invention a friction pad such an asbestos pad could be used. However it is believed that because of the potential of the clogging of the friction means 20 by rail, grime and dirt it would be desirable to include scrapers to substantially remove said dirt and grime ahead of said friction means 20.

In preferred embodiments of the present invention a cutting tool, in particular but not solely a cutting tool 21 designed to cut into the surface of the rail is utilised as the friction means 20. The cutting tool 21 can be adjusted so that the depth of cut can be varied so as to vary the amount of resistance and movement between the rail and the vehicle. It is also believed that use of a cutting tool 21 will dissipate a significant proportion of the energy necessary to decelerate or brake the vehicle. Said energy being dissipated by heating the material removed from the rail surface and also perhaps to a lesser extent being dissipated in the form of energy required to cut the material.

Therefore it will be seen by those skilled in the art to which the invention relates that when braking or decelerating utilising at least preferred forms of the present invention the vehicle lowered is in a stable position. It is believed that this lowered position resulting in additional stability will provide an added safety factor.

In preferred forms of the present invention manually operable means for raising the vehicle are provided. Therefore in the event of a suspension failure the friction means 20, that is friction pad or cutting tool can be lifted clear of the rail.

In preferred forms of the invention there is also provision for control of the suspension system so that the trailing edge of the vehicle is lowered first and therefore braked first. It is believed that the trailing edge breaking will increase the directional stability of the vehicle and thereby reduce the chance of derailment.

It is believed that the present invention is particularly suited to lightweight rail vehicles as lightweight rail vehicles of course lack the mass of conventional heavy rail

vehicles. Extensive damage may be caused if said lightweight rail vehicle collides with a conventional heavier rail vehicle or if said lightweight rail vehicle collides with other objects such as a car, for example, at a level crossing.

Preferred forms of the present invention provide an effective breaking system which it is believed will help reduce the chance of a collision.

It is therefore believed that the use of lightweight rail vehicles is facilitated by at least preferred forms of the present invention.

In conventional rail vehicles there is a need for the provision of inter-carriage passenger access so that passengers can utilise seating throughout the train. It has been found that where the occupancy or capacity of a rail carriage is not obvious from the outside, passengers will tend to favour the front most unit. In this situation it is therefore desirable to provide inter-carriage access. However there is a problem involved with the provision of inter-carriage access in that the passage has to be capable of handling the twists, angles and off sets between the carriages so interconnected. The necessity to provide inter-carriage access also results in the various carriage units being difficult to couple and decouple, and may require additional time and labour when coupling or decoupling trains.

It is believed desirable to eliminate the inter unit passageway and in particular it is believed that the provision of a lightweight rail vehicle is enhanced if the inter carriage unit passageway or access is eliminated. This results in a simpler construction and enables the vehicles to be coupled and decoupled more simply without a need to deal with the inter carriage unit access means. In this situation there is of course still the problem of passengers tending to favour the front most unit 3 and if passengers are unable to ascertain the loading of a particular unit may result in the overcrowding of the front most units but the under utilisation of units at or towards the rear 4 of the train.

Preferred forms of an aspect of the present invention recognises this difficulty and provide for an indication 100 of the occupancy of each carriage unit on a display outside of each carriage unit. This enables passengers or potential passengers or users to see which units have passenger room available. It is believed that this will result in better utilisation of the carriage units.

Various means of counting people, passengers or users present on a carriage unit are possible. For example, there could be provided on the train a turn-style, light beams broken by the entrance of passengers, radar detection means and step micro switches. However, it is believed that these means have inherent limitations and inaccuracies. Although the number of persons or passengers present in a carriage unit need not be indicated with great accuracy it is desirable that a reasonable degree of accuracy be achieved. It is also desirable that any said system be easy to maintain and not easily subject to vandalism. A preferred form of an aspect of the present invention utilises the soft characteristic and the lay of an air suspension system which is present in preferred forms of the present invention. The "kick" provided to said system when passengers mount or dismount is used to provide an indication of the average occupancy of a unit.

Preferred forms of the air bag suspension system move approximately 2cm per individual passenger entering a carriage unit. An upward suspension kick is indicative of a dismount, a downward kick is indicative of a mount. It is possible to add error correction to this system by zeroing the count when the carriage units are empty of passengers, for example, at a central terminus.

It is also possible to adjust the accuracy of the system by utilising physical passenger counts and then adjusting the sensitivity of the system to take account of this. It is believed that an occupancy count accuracy of 10% is achievable and that this will provide the necessary accuracy. The display 100 of said passenger count may be, for example, by LED display.

Preferred forms of this invention relates to passenger rail vehicles, specifically but not exclusively to the class broadly called Rapid Transit, and includes tramcars. It concerns a suspension system and associated means that caters for the requirements of a very lightweight construction vehicle (by rail standards), so that omnibus components and construction methods can be employed, for a significant reduction in capital and running costs. The stability of the system is such that the units can be used for high speed main trunk operation to serve other city centres during the urban off peak period, to significantly improve overall operational economy.

To achieve this lightweight construction, in the order of 16 tonnes for a 90 seat double-sided unit, as typified in the illustration of Fig 1 , the floorboards must be lowered to approximately 533mm or 21" above the rails for narrow gauge 1067mm (3'6") so that the required crosswind stability can be achieved. This height corresponds to the majority of platform levels in New Zealand, for ease of entry and exit. Broadly speaking, every inch of additional height will require an extra ton of weight of the vehicle. For standard gauge units of this weight the maximum height would be approximately 686mm or 27", rail to floorboards.

For the purposes of the description, a 3 axle vehicle is described although for high speed or small turning circles or handling very irregular track, lightweight bogies may be employed at greater cost. As the preferred suspension is 3 single axles for a double unit, the problems of maintaining axle stability at speeds in excess of 80 kph, considering the condition of typical track and the comparatively small reaction mass of the lightweight body, becomes a serious problem.

This is overcome in preferred forms of the invention by regarding the whole vehicle as a very long wheelbase three axle bogie, in a form that requires minimal reaction mass. This is achieved by referencing the central axle, via links to bisect the angle between the two units, so the axle is maintained substantially at right angles to the track as determined by the long bodies of the passenger compartments. This is very stable inherently, and does not rely on a reaction mass. The links need not be mechanical, and could be hydraulic or other suitable means which will be obvious to those skilled in the art to which the invention relates for example.

The simplified linkage according to one preferred form of the present invention shown in Fig 3 to illustrate this principle has a side effect of wheel offset, and although it reduces the overhang at the centre of the vehicle from track centre, is inherently unstable for the vehicle as a whole, and would need heavy damping.

It is also preferred to apply the motive power to this axle as it bears approximately half the vehicle weight for traction, it is very insensitive to unbalanced thrust due to wheel slip or varying gauge with respect to track centre, and it is believed to be very simple to use a modified bus back axle.

This very stable central axle can now be used as the reference for the end axles, either of which may be the critical leading axle, depending on the direction of travel of the vehicle. The linkage of the axles will preferably by one of the various variations of

cross linking, preferably with series dampers in the linkage, to aid the lead-in and lead- out tracking error illustrated in Fig 4.

With the floorboard height in the order of 533mm or 21 " in preferred forms of the present invention, the motor and its transmission will only be 64mm or 2 ^! 2 ^M to 76mm or 3" above the rail height, so unless a very hard ride, for the passengers, is likely to be tolerated, a height controlled suspension, be it pneumatic, hydraulic or other, is to be preferred, with firm anti-roll means.