GB2219558A - Road-rail vehicle - Google Patents

Abstract

A road-rail vehicle is equipped with four load carrying actuators 1, 2, 3 and 4 upon which the rail running wheels are mounted in such a manner as to be linked across the vehicle in order to follow track curvature and to fold into pairs into a locked stowed position 9. The actuator or legs pivot (a) about axes which lie across the vehicle so that they pivot in an arc lying in the longitudinal vertical plane, and away from the fore/aft mid point of the vehicle, and (b) about their own longitudinal axis; so the rail wheels, when parked, lie substantially flat against the underside of the vehicle. The actuators may be hydraulic rams which can be controlled so as to control the stability and attitude of the vehicle, particularly when equipped with a high level working platform. <IMAGE>

Description

RAIL RUNNING MEHEhGISM FOR Rf1AD RAIL VERICLES.

This invention relates to load carrying road vehicles adapted for. use upon standard gauge railway tracks and in particular to the rail running gear and supports.

Road rail vehicles have been in use for some time, mainly for passenger transport. Where vehicles of a particular form have been used for load or equipment carriage they have been found generally lacking in some otherwise desirable features. For example, there has been no way of stabilizing or means for compensating for cant, both of which are essential when working 'from an on-board elevating platform, no means for absorbing shocks from travelling over track irregularities or for inching control whilst working from an elevated work station. Additionally, rail running gear is usually fixed at front and rear of such vehicles and thus drastically reduces or impairs approach and retreat angles for embankment climbing etc.

The invention described herein sets out to overcome these difficulties and short comings by various means including the following: An envisaged embodiment provides rail running wheels mounted in pairs on rocking beams (in the manner of one side of a convential four wheel bogie) with each beam mounted in swivable manner upon hydraulic rams, such rams being themselves pivoted upon an axis perpendicular to the line of action of the ram and each ram being interconnected in a variety of ways via metering orifices and control valves to achieve stabilization, attitude change and suspension/ride damping. By fitting a coil compression spring over the rod element of the actuators and housed between rocking beam and body of the actuators these can be used to accept normal vehicle loadings thus leaving the actuator rods free to float.

A particular embodiment of this invention will now be described by way of example in association with the following drawings: Fig. 1 depicts a front view of the vehicle mounted on rail running gear upon a cant and with an elevated overhung work platform.

Fig. 2 indicates a front view of the vehicle rail mounted with work platform retracted and the whole within railway loading gauge.

Fig. 3 shows a side view of vehicle in rail running order with work platform retracted for travel.

Fig. 4 shows a front view of vehicle in road order rail running gear stowed and platform retracted.

Fig. 5 shows a side view of vehicle in conditions as in Fig. 4.

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Referring to Figs. 1-5 a road rail vehicle has its rail running and guidance roller mounted upon telescopic spring assisted actuators in this case hydraulic rams at or near the extreme of the vehicle chassis but set to match the railway gauge width.

The near vertically aligned actuators 1,2,3 and 4 are free to pivot upon their own longitudinal axis 5 and at the same time adjustably able to swing in an arc 6 (Fig. 5) having a plane of action parallel to the longitudinal axis of the vehicle, in order that the rail running wheels 7 system may be lowered into rail contact 8 and raised into the stowed position 9 for road travel.The rail running and guidance wheels 10 are mounted at the lower ends of the actuators 1 - 4, in this case in pairs 11 within a pivoted rocking beam 12 in such a manner as to be linked across the vehicle at its front by link 23 and rear by link 24 and thus are able to follow the railway track curvature whilst at the same time causing similar movement of the linked elements when one of these is rotated through 900 into stowed position 9 after the actuators 1-4 have been caused to swing upwards and outwards through an angle greater than 900 in order to give approach 14 and retreat 15 angle clearance.It follows that if the actuators 1-4 in this case hydraulic cylinders are interconnected in various ways by means of control orifices and direction control valves (not shown) fluid pressure within the cylinders may be used to produce stability, transverse and longitudinal, for example to offset the effects of an overhung elevated work platform offset as at 17, at the same time by transverse pressure variation may be used to adjust for the action of cant (side slope) as at 18 and by suitable interlinked controlled flow may be used to adjust the suspension/ride damping effects, or to vary the ratio of rear tyre induced tractive effort to vehicle rear axle load by adjustment of the pressure to actuators 3 and 4.

As an additional enhancement it is proposed that the rear two rail engaging pairs of wheels 19 and 20 be driven by a friction contact device 21 in turn powered by a separate motor 22, air, hydraulics or electric in order to produce slow speed precise inching control which could be remotely actuated for example as an overriding system from the elevated work platform, thus excluding other forms of transmissions when the platform is in use and extended.

Claims (9)

CLAIMS.

1. A rail running and guidance mechanism for use with road/rail vehicles having the rail engaging wheels attached to the lower end of a multiplicity (ideally 4) of supportactuators each able to rotate about its own longitudinal axis and clampably pivot about an axis perpendicular to said longitudinal axis in order to permit such actuators to move in an arc in a plane parallel to the longitudinal axis of said road/rail vehicle and be locked in position either to engage rail running-wheels with the rail head or having been swung in an arcuate manner about said perpendicular axis outward and into a stowed (for road travel) position whilst at the same time such rail engaging wheels are caused to be linked across the vehicle in pairs by a rod like connection one at the forward and one at the rearward rail engaging wheel positions in order that said rail engaging wheels are enabled to follow implicitly in pairs any track curvature and thus be able to negotiate points and the like when said rail engaging wheels are locked in the rail engaging position, such rod like ccections also enabling said rail engaging wheels to lie flat in a near horizontal position when locked into a road travel position having been caused to rotate through 900 about the longitudinal axis of said support actuators thus improving the approach and retreat angles of the vehicle as a whole.

2. A rail running and guidance mechanism as in Claim 1 wherein the transport actuators may be hydraulic cylinders (ram) and thus permit free rotation of the rail engaging wheels about the longitudinal axis of said cylinders1

3. A rail running mechanism as in Claims 1 and 2 wherein the support actuators may be pneumatic cylinders or electro mechanical linear actuators in order to permit free rotation about their longitudinal axes.

4. A rail running and guidance mechanism as in Claims 1 and 2 wherein the hydraulic cylinders (rams) may be interconnected in one or more of a variety of ways to appropriate orifices and direction control valves in order that said actuators may be used by means of their internal forces to achieve longitudinal/ transverse road/rail vehicle stability to counteract the effects of said vehicle offset loadings produced when athwart a canted (side sloping) track and/or when said vehicle is equipped with an elevated and offset work platform or lifting device said interconnected internal forces may also be used to control suspension and ride damping characteristics or to vary the load carried by any of the road/rail vehicle tyres in contact with the rail head and thus vary their tractive effort capability.

5. A mechanism such as described in Claims 1-4 wherein the rail engaging wheels are arranged in tandem pairs within a rocking beam device akin to one side of a conventional four wheel railway bogie pivotally attached to each support actuator perpendicular to the longitudinal axis of said actuator in order to double the number of rail engaging wheels in contact with the rail head at each actuator position.

6. A mechanism such as described in Claims 1 and 2 wherein one or more of the twin wheeled bogies is equipped with a friction drive device contacting both wheels of that bogie and driven by a power source independent from the carrying vehicle axles as for example an hydraulic air or electric motor such motors being controlled in an overriding manner to produce a safe precise inching traction speed which may be driven from a remote position only, such as upon an elevated working platform affixed to the carrying vehicle.

7. A mechanism such as described in Claims 1-3 wherein'a close coiled circular compression spring is housed between and is thus effective therein the bogie mounting frame and the body of each of the actuators in such a manner as to be constrained in the longitudinal (near vertical) axis by these two elements and by the actuator rod in the perpendicular plane to this axis, such springs being thus able to carry the normal loads imposed by the vehicle whilst leaving the actuators free to float along and rotate around their longitudinal axes.

8. A mechanism such as described in Claims 1-4 wherein the road rail running gear carrying actuators may derive their power from any one of a variety of sources air, hydraulic, electric with control equipment and circuit interlinking to enable independent predicted and controlled actuator functions to take place.

9. A mechanism such as described in Claims 1-9; and as depicted in the encIosed set of drawings.