GB2052406A

GB2052406A - Road/rail vehicle

Info

Publication number: GB2052406A
Application number: GB8016734A
Authority: GB
Original assignee: MATISA Ltd
Current assignee: MATISA Ltd
Priority date: 1979-05-25
Filing date: 1980-05-21
Publication date: 1981-01-28
Also published as: GB2052406B

Abstract

The vehicle (1) has road wheels (7) and rail wheels (4, 5) which are movable between extended and retracted positions (as illustrated). The vehicle has selectively engageable first and second drive means for transmitting power from the engine to the road and rail wheels respectively. The first drive means can be a conventional transmission while the second drive means includes an hydraulic motor. When the vehicle is in a rail going condition with its rail wheels in their extended positions the road wheels are maintained out of contact with the track rails by deflection restriction means operable on the suspension means of the road wheels (7). The vehicle also has a sub-frame at the rear to which the rear rail wheels (5) and the bodies of lifting jacks (9) of auxiliary apparatus are mounted. The sub-frame is vertically movable on slides (13). The auxiliary apparatus may include means for tamping, packing, levelling and/or lining. <IMAGE>

Description

SPECIFICATION Road/rail vehicle This invention relates to a road/rail vehicle and more particulariy, but not exclusively, to such a vehicle for use in tamping.

The present invention includes a road/rail vehicle comprising: a chassis; an engine; front and rear road wheels mounted for limited movement relative to the chassis through suspension means; front and rear rail wheels retainable in retracted positions when the vehicle is in a road going condition and movable to extended positions for engaging track rails to put the vehicle in a rail going condition, in which rail going condition the road wheels are out of contact with the track rails; and first and second drive means selectively engageable for transmitting power from the engine either to (i) at least the front or rear road wheels orto (ii) at least the front or rear rail wheels.

For a better understanding of the features and advantages ofthe invention, an embodiment thereof, which is given by way of example only will now be described with reference to the accompanying drawing which schematically illustrates in side elevation a road/rail tamper 1 which comprises a road going vehicle 2 based on a truck having engine and chassis with auxiliary apparatus 3 mounted at its rear. The vehicle has front and rear road wheels mounted to the chassis through suspension means for limited movement relative to the chassis. The vehicle is also provided with front and rear rail wheels 4 and 5. The rail wheels are retained in retracted positions (as illustrated) whilst the tamper is in a road going condition and are movable to extended positions when the tamper is in a rail going condition.A combined turntable-jacking arrangement 6 facilitates transfer of the tamper from road to rail.

When the tamper is in a road going condition, the vehicle engine, which conventionally would be a petrol or diesel internal combustion engine, drives the rear road wheels 7 through a conventional vehicle road transmission or first drive means. When the tamper is in a rail going condition the vehicle transmission is disengaged and the vehicle engine is used to drive a second drive means comprising an hydraulic motor. The hydraulic motor is used to drive the front and/or rear rail wheels 4, 5 and to operate the combined turntable-jacking arrangement 6, and a tamping head 8 and lifting jacks 9 on each side of the auxiliary apparatus (only one head 8 and jack 9 is illustrated in the drawing).Braking of the tamper in a rail going condition is effected using the hydraulic motor and disc brakes on the rail wheel axles, and the tamper may be driven in a rail going condition either from the vehicle cabin 10 or a tamping operating seat 11.

In order to transfer the tamper from a road going to a rail going condition, the tamper is driven so that it straddles the track on which it is to run, with the front road wheels on one side of the track, the rear road wheels on the other side of the track and the turntable-jacking arrangement 6 between the two rails of the track. This manoeuvre can best be carried out where the road is substantially level with the top of the rails for example at a level crossing or a goods or industrial yard, or by using ramps.

The road transmission is disengaged and the vehicle engine is drivingly connected to the hydraulic motor. Deflection restriction devices are activated on the road wheel suspension means or units and the turntable-jacking arrangement 6 is lowered to lift the tamper until there is a vertical clearance between the road wheels and the rails. The tamper is then turned on the turntable by hand until the rail wheels are aligned with the track rails. The front rail wheels 4 are lowered by means of hydraulic piston and cylin derarrangements 12, which are powered by the hydraulic until they reach their extended positions, in which positions they are secured by locking pins, not shown.

The auxiliary apparatus mounted to the vehicle illustrated is tamping or packing apparatus suitable for levelling and/or lining in main line relaying joint peaking and branch line smoothing.

The lifting jacks 9 of the auxiliary apparatus are utilized in effecting movement of the rear rail wheels to their extending position. The rear rail wheels and auxiliary apparatus are mounted on a sub-frame for vertical movement on two slides 13. The bodies of the lifting jacks are secured to this sub-frame and for moving the rear rail wheels to their extended positions the lifting jacks are first operated to lower their feet 14 into engagement with the ground beside the track thus taking the weight of the rail wheel/tamping apparatus sub-frame. Locking pins (not shown) are removed whereupon the sub-frame descends down the slide until the rail wheels are in contact with the rails. Since the bodies of the jacks 9 are carried by the sub-frame the descent of the subframe causes the jacks to partially retract.The rear rail wheels are then secured in their extended condition and the lifting jacks may be fully retracted so that the feet 14 are lifted out of contact with the track.

Lastly, the turntable-jacking arrangement 6 is retracted so that the tamper is free to travel on the track rails on its rail wheels, to the site where it is required. Whilst tamping the feet 14 are once more brought into contact with the ground at either side of the track by the lifting jacks 9 to provide additional support and stability to the vehicle. When the feet 14 of the lifting jacks 9 are in contact with the ground the jacks 9 may be operated by the hydraulic motor to lift the sub-frame and rail clamps attached thereto for lifting the rail slightly during tamping operations or for levelling and lining.

It should be noted that when the tamper is in a rail going condition the road wheels are maintained completely out of engagement with the rails so that wear on the road tyres and transmission is avoided when the tamper is travelling on rails and is being used in a tamping operation. This is achieved by arranging for a small clearance between the road wheels and the rails when the rail wheels engage the rails in their extended positions and by restricting downward deflection of the road wheel suspension units by means of the deflection restriction devices referred to above.

The utilization of the lifting jacks 9 of the tamping apparatus which cooperate with rail clamps to effect lifting of the rail in a tamping operation as a means enabling the movement of the rear rail wheels from retracted positions to extended positions is a particularly advantageous feature of the illustrated tamper.

It will be appreciated that we have devised a vehicle which although primarily road-going is readily adapted to a rail going condition.

Claims

1. A road/rail vehicle comprising: a chassis; an engine; front and rear road wheels mounted for limited movement relative to the chassis through suspension means; front and rear wheels retainable in retracted positions when the vehicle is in a road going condition and movable to extended positions for engaging track rails to put the vehicle in a rail going condition, in which rail going condition the road wheels are out of contact with the track rails; and first and second drive means selectively engageable for transmitting power from the engine either to (i) at least the front or rear road wheels or to (ii) at least the front or rear rail wheels.

2. A vehicle as claimed in claim 1, further comprising: a sub-frame to which the rear rail wheels are mounted, the sub-frame being vertically slidable on slides fixed relative to the chassis; and at least one jack having a body fixed to the sub-frame, the rear rail wheels being movable to their extended positions by sliding movement of the sub-frame on the slides on retraction of the or each jack.

3. A vehicle as claimed in claim 2, wherein the or each jack also serves as a jack of auxiliary apparatus.

4. A vehicle as claimed in claim 3, wherein the auxiliary apparatus comprises means for tamping.

5. A vehicle as claimed in claim 2,3 or 4, wherein there are two jacks one disposed at either side of the chassis.

6. Avehicle as claimed in any one of the preceding claims, further comprising deflection restriction means operable on the suspension means to prevent the road wheels coming into the contact with the track rails when the vehicle is in a rail going condition.

7. A vehicle as claimed in any one of the preceding claims, wherein the second drive means comprises an hydraulic motor.

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