GB2150902A - Towing assembly for recovering broken-down vehicle - Google Patents

Abstract

A towing assembly for recovering a broken-down vehicle comprises an extensible beam carrying a pair of wheel receiving frames. Between the inner end of the beam and the underside of the towing vehicle there is provided a fluid-powered piston/cylinder device. In use, the beam is lowered to bring the wheel frames into ground engagement, and two of the wheels of the vehicle are pushed onto the wheel frames. The beam is lifted, wheeled carriages 18 are then interposed between the ground and the wheel frames, and the beam is lowered, the wheeled carriages taking some, but not all, of the weight of the towed vehicle. The relative amounts of the weight carried by the wheeled carriages and the rear wheels of the towing vehicle can be varied by varying the pressure in the piston cylinder device. <IMAGE>

Description

SPECIFICATION Improvements relating to the towing of vehicles This invention is concerned with improvements relating to the towing of vehicles, and particularly relates to towing assemblies of the kind utilised on towing vehicles in the recovery of broken-down vehicles.

A conventional towing assembly comprises a supporting device (which is conventionally extensi le) secured or adapted to be secured at one end (usually in a manner in which relative pivotal movement is permitted) to a towing vehicle, and comprising at its outer end means by which the wheels (which may be front or rear) of a towed vehicle may be secured, and power operated means to move the supporting device up and down. Thus (for example) with said outer end of the supporting device on or adjacent the ground, the wheels of the towed vehicle may be mounted thereon, and the power operated means operated to lift said outer end and thus the wheels of the towed vehicle from the ground.

Such conventional equipment suffers from the following disadvantages: (a) it increases the load on the rear axle of the towing vehicle, this in effect limiting the load which can be towed without the use of heavy towing trucks; (b) it reduces the load on the front wheels of the towing vehicle, which affects steering, requiring the use of unnecessarily heavy towing vehicles or the use of auxiliary weights to maintain the front axle loading at an acceptable level. This in turn causes problems of steering when the vehicle is not towing.

These problems are particularly exacerbated when, due to the nature of the vehicles, an extensive length of supporting device is required to be used (e.g. when the towed vehicle has a forwardextensive structure).

According to this invention, there is provided a towing assembly comprising: (a) a supporting device comprising means by which the assembly may be secured to a towing vehicle, and means on or to which the wheels of a towed vehicle may be secured, and (b) a wheeled carriage interposed or adapted to be interposed between the supporting device and the ground.

In this manner, part at least of the weight of the towed vehicle may be transmitted to the ground through the wheeled carriage. Where said means on or to which the wheels of a towed vehicle may be secured comprises two wheel frames, one for each of the two wheels of the towed vehicle, preferably two wheeled carriages are utilised, one interposed or adapted to be interposed between each of the wheel frames and the ground.

Preferably, the supporting device and the wheeled carriage comprise releasable interengaging means to enable the supporting device to be lowered onto and into co-operable engagement with the wheeled carriage. Thus, in use, the part of the supporting device remote from the towing vehicle may be placed on the ground and the towed vehicle may be pulled, pushed or driven onto the supporting device.

Said outer end with the towed vehicle supported thereon may be lifted, and the wheel frame interposed between the supporting device and the ground, and the supporting device lowered onto the wheeled carriage.

Alternatively, the invention may be utilised with one or more wheeled carriages semi-permanently secured to the underside of the supporting device: such an arrangement may be used particularly where the towing vehicle comprises a hoist by which the towed vehicle may be lifted onto the supporting device.

In this manner, simple towing of a vehicle may be effected without the use of complicated equipment and/or whilst significantly reducing the disadvan tages set out above.

Preferably the assembly comprises power operated means operative between the towing vehicle and the supporting device to effect movement of the supporting device. Thus the power operated means may be a hoist on the vehicle, but is more advantageously provided by a fluid power piston/cylinder device.

Not only may such power operated means be effective to carry out raising and lowering of the supporting device prior to towing of a vehicle is commenced, but advantageously may be utilised to adjust the proportion of the load transmitted to the ground through the wheeled carriage and that transmitted to the towing vehicle.

Preferably control means is provided to facilitate a desired apportionment: such control means may comprise a manually operable control valve to determine the output force of the power operated means, and/or gauges to illustrate the loading applied by the supporting device to the towing vehicle. Thus the loading applied to the wheeled carriage may be reduced, at the expense of some loading to the towing vehicle, permitting the wheeled carriage to be less robust than would otherwise be necessary, and/orto minimise damage in the event of breakage in use of the wheeled carriage.

According to this invention, there is also provided a method of recovering a broken-down vehicle involving the use of a towing vehicle and a supporting device mounted on the towing vehicle, and power operated means to move the supporting device in a heightwise direction, and the steps: (a) with the supporting device in a first position moving the wheels of the towed vehicle into engagement with the supporting device; (b) elevating the supporting device; (c) interposing between the supporting device and the ground a wheeled carriage; (d) lowering the supporting device into the wheeled carriage.

There will now be given a detailed description, to be read with reference to the accompanying drawings, of a preferred embodiment of this invention, which has been selected for the purposes of illustrating the invention by way of example.

The accompanying drawings show schematically three stages in the use of the invention, in the mounting of a vehicle to be towed, in relation to a towing vehicle.

In the preferred embodiment of this invention, a towing vehicle is utilised when comprises, at its rear end, supporting brackets 6 between which there is pivotally mounted on extensible beam 8, the beam 8 at its outermost end carrying a pair of wheel frames 10. Between the inner end of the beam 8 and the underside of the towing vehicle there is provided power operated means 12, in the form of one or more fluid-powered piston/cylinder devices.

Mounted on the vehicle is a control unit 14, which comprises various control elements, including a control valve to adjust the flow of fluid under pressure to the piston/cylinder device, and gauges to indicate the pressure of the fluid applied.

The system also involves the use of two wheeled carriages, each comprising a pair of caster-like wheels 16 and a stem 18, which may be inserted into a socket adjacent a respective one of the wheel frames 10.

In the recovery of a broken-down vehicle, the towing vehicle is positioned in front of and in line with the vehicle to be recovered, the hand brake applied and the engine running. The isolator switch in the control circuit is switched on, and the control lever of the hydraulic power pack is operated to lower the beam 8 and wheel frames 10 to the ground.

The broken-down vehicle is pushed onto the wheel frame, and the control lever of the power pack is operated to lift the beam 8 to a suitable height above the ground, as is shown in Figure 2. The spigots 18 of the two wheeled carriages are then inserted into their respective sockets beneath the wheel frames, and are secured in position. The control lever is then operated to lower the beam 8 to a point at which the wheeled carriages 16 just touch the surface of the road.

At this point, the pressure gauge of the control system reads a maximum, indicating that the entire weight of the front wheels of the towed vehicle is being supported by the power operated means 12, and is thus taken on the rear axle of the towing vehicle.

By further operation of the control device, the pressure under which the power operated means 12 operates may be reduced to lowerthe wheeled carriages into firm contact with the ground, reducing some of the weight on the rear axle of the towing vehicle, and imposing some loading on the wheeled carriages.

It is envisaged that an appropriate apportionment over the load may be 50% between the wheeled carriages and the rear wheels of the vehicle, although other apportionments may be selected if appropriate.

Claims (15)

1. Atowing assembly comprising: (a) a supporting device comprising means by which the assembly may be secured to a towing vehicle, and means on or to which the wheels of a towed vehicle may be secured; and (b) a wheeled carriage interposed or adapted to be interposed between the supporting device and the ground.

2. Atowing assembly according to claim 1 wherein said means on or to which the wheels of a towed vehicle may be secured comprises two wheel frames, one for each of two wheels of the towed vehicle.

3. Atowing assembly according to claim 2 comprising two wheeled carriages, on interposed or adapted to be interposed between each of the wheel frames and the ground.

4. A towing assembly according to any one of claims 1,2 and 3 wherein the construction and arrangement is such that, in use, the supporting device with the towed vehicle supported thereon may be lifted, and the supporting device lowered onto the or each wheeled carriage.

5. A towing assembly according to claim 4 wherein the supporting device and the or each wheeled carriage comprise releasable interengaging means to enable the supporting device to be lowered onto and into co-operable engagement with said wheeled carriage or carriages.

6. A towing assembly according to any one of claims 1, 2 and 3 wherein the or each wheeled carriage is semi-permanently secured to the underside of the supporting device.

7. A towing assembly according to any one of the preceding claims comprising power operated means operative between the towing vehicle and the supporting device to effect movement of the supporting device.

8. A towing assembly according to claim 7 wherein the power operated means comprises a fluid power piston/cylinder device.

9. A towing assembly according to one of claims 7 and 8 wherein the power operated means is operative to adjust the proportion of the load transmitted to the ground through the wheeled carriage or wheeled carriages and that transmitted to the towing vehicle.

10. Atowing assembly according to claim 9 comprising control means to facilitate a desired apportionment.

11. A towing assembly according to claim 10 wherein the control means comprises a manually operable control valve to determine the output force of the power operated means.

12. A method of recovering a broken-down vehicle involving the use of a towing vehicle and a supporting device mounted on the towing vehicle, and power operated means to move the supporting device in a heightwise direction, and the steps: (a) with the supporting device in a first position, moving the wheels of the towed vehicle into engagement with the supporting device; (b) elevating the supporting device; (c) interposing between the supporting device and the ground a wheeled carriage; (d) lowering the supporting device onto the wheeled carriage.

13. A towing assembly constructed and arranged substantially as hereinbefore described with refer ence to the accompanying drawings.

14. A method of recovering a broken-down vehicle substantially as hereinbefore described with reference to the accompanying drawings.

15. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.