GB2148215A

GB2148215A - Road/rail vehicle

Info

Publication number: GB2148215A
Application number: GB08327804A
Authority: GB
Inventors: Keith Cecil Field; James Leslie Ralph Porter
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-10-18
Filing date: 1983-10-18
Publication date: 1985-05-30
Also published as: GB8327804D0

Abstract

A road vehicle is provided between its front and rear road wheels 7 with front and rear rail wheels 6 which are mounted on a turntable 1. The turntable 1 is lockable in a central position by a locking device 3 and the rail wheels 6 are lowerable with respect to the turntable 1 by hydraulic cylinders 4 from stowed positions for engagement with the lines of a rail track. The provision of the turntable enables the rail wheels to be aligned in their stowed positions with the track lines after the vehicle has been driven on its road wheels to straddle the track, whereupon the hydraulic cylinders can lower the rail wheels into engagement with the track lines and subsequently cause the road wheels to be raised clear of the ground and track lines so that the vehicle can be rotated on turntable 1 into alignment with the track. <IMAGE>

Description

SPECIFICATION Road/rail vehicle This invention relates to a road/rail vehicle, that is a vehicle which is adapted to travel on either a road surface or a rail track.

It is known to provide a road going vehicle with respective sets of rail wheels mounted in front and at the rear of the vehicle and lowerable to engage the lines of a rail track to allow the vehicle to run on the track. A major disadvantage of such vehicles is that the vehicle has to be precisely positioned relative to the rail track prior to the rail wheels being lowered to engage the lines thereof.

An object of this invention is to avoid this disadvantage.

The present invention provides a road/rail vehicle provided between its front and rear road wheels with front and rear rail wheels mounted on a mounting means which is rotatable with respect to the vehicle from a predetermined lockable position relative thereto, and means for lowering said rail wheels from a stowed position for engaging the lines of a rail track.

In order that the invention may be well understood an embodiment thereof, which is given by way of example only, will now be described, with reference to the accompanying drawing which shows a Land Rover (RTM) modified to provide a road/rail vehicle.

The Land Rover (RTM) has its normal transmission, brakes, suspension and road wheels, the latter indicated by reference numeral 7. The track of the road wheels 7 is such that a portion of the running edge of the tyres will bear on the head of railway rails laid to the standard gauge.

The vehicle is fitted with a turntable 1 consisting of a rotating bearing 2 capable of being locked in a central position with respect to the vehicle for travelling by means of a locking device 3. The turntable carries four flanged rail wheels 6 I two front rail wheels and two rear rail wheels. Each rail wheel 6 is fitted with a wheel lock 5 to prevent its rotation and each rail which is mounted on a hydraulic cylinder 4 supplied with fluid from a hydraulic pump driven by the engine of the vehicle and piped in such a manner that varying fluid pressure can be supplied.

In use the vehicle runs on the road in the normal manner until reaching a railway line at any convenient point. It is driven across the track at any angle depending on the line of access and is stopped with the middle of the vehicle coincident with the middle of the railway track.

The turntable locking device 3 is released and the turntable is rotated until the railwheels are aligned with the rails of the railway track.

Hydraulic fluid at standard system pressure is supplied to the cylinders 4 and the railwheels are lowered until they make contact with the rails of the track. Continued operation of the cylinders lifts the vehicle until the roadwheels are clear of the ground and the rails and thus the vehicle can be rotated until it is again aligned with the rail wheels.

Releasing the pressure in the cylinders 4 permits the road wheels to make contact with the rails of the track.

The turntable is then locked in its central position with respect to the vehicle by means of the device 3 and the rail wheels locks 5 are released to permit free rotation of the rail wheels.

Hydraulic fluid at low pressure is admitted to the cylinders 4 thus causing a predetermined portion of the vehicle weight to be carried by the railwheels. Thus when the vehicle is driven in either direction all traction and braking forces are taken through the road wheels 7 and vehicle guidance is produced by the rail wheels 6.

Proportioning of the vertical load between the road and rail wheels prevents damage to the road wheel tyres when running on the Qnarrow' rail head and prevents the lateral forces causing derailment of the rail wheels.

Advantageously the vehicle will be provided with means for selectively setting the hydraulic pressure in the cylinders 4 so that the load on the road wheels can be increased or decreased as required in proportion to the load on the vehicle.

Whilst in the described arrangement the rail wheels are mounted for lowering from stowed positions relative to the turntable, it will be appreciated that, ground clearance permitting, the rail wheels may be fixedly mounted with respect to the turntable and the turntable mounted for lowering from a stowed position relative to the vehicle.

From the foregoing it will be appreciated that the invention may be brought into effect by modifying cross-country vehicles such as Land Rovers (RTM).

As stated previously the track of a Land Rover (RTM) is such as to allow the road wheels to run on the rails of a standard gauge track. Where the track of the vehicle does not allow this, or where it is desired not to have the road wheels run on the rails, the vehicle is provided with a hydraulic motor to drive the rail wheels and the rail wheels are provided with their own braking system. In such a vehicle, the full weight of the vehicle is carried by the rail wheels when the vehicle is in a rail going condition.

1. A road/rail vehicle provided between its front and rear road wheels with front and rear rail wheels mounted on a mounting means which is rotatable with respect to the vehicle from a predetermined lockable position relative thereto, and means for lowering said rail wheels from stowed positions for engaging the lines of a rail track.

2. A road/rail vehicle having front and rear road wheels and provided with rail wheels, its rail wheels being located between its front and rear road wheels and comprising front and rear rail wheels mounted on mounting means which is rotatable with respect to the vehicle from a predetermined lockable position relative thereto, and means for lowering said rail wheels from stowed positions for engaging the lines of a rail track.

3. A vehicle as claimed in claim 1 or 2, wherein

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Road/rail vehicle This invention relates to a road/rail vehicle, that is a vehicle which is adapted to travel on either a road surface or a rail track. It is known to provide a road going vehicle with respective sets of rail wheels mounted in front and at the rear of the vehicle and lowerable to engage the lines of a rail track to allow the vehicle to run on the track. A major disadvantage of such vehicles is that the vehicle has to be precisely positioned relative to the rail track prior to the rail wheels being lowered to engage the lines thereof. An object of this invention is to avoid this disadvantage. The present invention provides a road/rail vehicle provided between its front and rear road wheels with front and rear rail wheels mounted on a mounting means which is rotatable with respect to the vehicle from a predetermined lockable position relative thereto, and means for lowering said rail wheels from a stowed position for engaging the lines of a rail track. In order that the invention may be well understood an embodiment thereof, which is given by way of example only, will now be described, with reference to the accompanying drawing which shows a Land Rover (RTM) modified to provide a road/rail vehicle. The Land Rover (RTM) has its normal transmission, brakes, suspension and road wheels, the latter indicated by reference numeral 7. The track of the road wheels 7 is such that a portion of the running edge of the tyres will bear on the head of railway rails laid to the standard gauge. The vehicle is fitted with a turntable 1 consisting of a rotating bearing 2 capable of being locked in a central position with respect to the vehicle for travelling by means of a locking device 3. The turntable carries four flanged rail wheels 6 I two front rail wheels and two rear rail wheels. Each rail wheel 6 is fitted with a wheel lock 5 to prevent its rotation and each rail which is mounted on a hydraulic cylinder 4 supplied with fluid from a hydraulic pump driven by the engine of the vehicle and piped in such a manner that varying fluid pressure can be supplied. In use the vehicle runs on the road in the normal manner until reaching a railway line at any convenient point. It is driven across the track at any angle depending on the line of access and is stopped with the middle of the vehicle coincident with the middle of the railway track. The turntable locking device 3 is released and the turntable is rotated until the railwheels are aligned with the rails of the railway track. Hydraulic fluid at standard system pressure is supplied to the cylinders 4 and the railwheels are lowered until they make contact with the rails of the track. Continued operation of the cylinders lifts the vehicle until the roadwheels are clear of the ground and the rails and thus the vehicle can be rotated until it is again aligned with the rail wheels. Releasing the pressure in the cylinders 4 permits the road wheels to make contact with the rails of the track. The turntable is then locked in its central position with respect to the vehicle by means of the device 3 and the rail wheels locks 5 are released to permit free rotation of the rail wheels. Hydraulic fluid at low pressure is admitted to the cylinders 4 thus causing a predetermined portion of the vehicle weight to be carried by the railwheels. Thus when the vehicle is driven in either direction all traction and braking forces are taken through the road wheels 7 and vehicle guidance is produced by the rail wheels 6. Proportioning of the vertical load between the road and rail wheels prevents damage to the road wheel tyres when running on the Qnarrow' rail head and prevents the lateral forces causing derailment of the rail wheels. Advantageously the vehicle will be provided with means for selectively setting the hydraulic pressure in the cylinders 4 so that the load on the road wheels can be increased or decreased as required in proportion to the load on the vehicle. Whilst in the described arrangement the rail wheels are mounted for lowering from stowed positions relative to the turntable, it will be appreciated that, ground clearance permitting, the rail wheels may be fixedly mounted with respect to the turntable and the turntable mounted for lowering from a stowed position relative to the vehicle. From the foregoing it will be appreciated that the invention may be brought into effect by modifying cross-country vehicles such as Land Rovers (RTM). As stated previously the track of a Land Rover (RTM) is such as to allow the road wheels to run on the rails of a standard gauge track. Where the track of the vehicle does not allow this, or where it is desired not to have the road wheels run on the rails, the vehicle is provided with a hydraulic motor to drive the rail wheels and the rail wheels are provided with their own braking system. In such a vehicle, the full weight of the vehicle is carried by the rail wheels when the vehicle is in a rail going condition. CLAIMS

3. A vehicle as claimed in claim 1 or 2, wherein said means for lowering said rail wheels comprises hydraulic means, and means for selectively setting the hydraulic pressure in said lowering means when said rail wheels engage the lines of a rail track.

4. A vehicle as claimed in any one of the preceding claims wherein the rail wheels are mounted for lowering from their stowed positions relative to said turntable by said lowering means.

5. A vehicle as claimed in any one of claims 1 to 3, wherein rail wheels are fixedly mounted with respect to the turntable and the turntable is mounted for lowering from a stowed position relative to the vehicle by said lowering means for lowering said rail wheels from their stowed positions.

6. A vehicle as claimed in any one of the preceding claims, wherein means are provided to drive and brake the rail wheels.

7. A vehicle as claimed in any one of the preceding claims, wherein said vehicle comprises a cross-country vehicle which has been modified by the provision of said rail wheels, mounting means and lowering means.

8. A road/rail vehicle substantially as herein described with reference to the accompanying drawing.