AU670445B2 - Road vehicle trailer - Google Patents

Description

AUSTRALIA

Patent Act COMPLETE SPEC I F ICATION

(ORIGINAL)

Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority: Related Art: o o Names(s) of Applicant(s): GRAEME McCAMM NELSON Actual Inventor(s): Graeme McCamm Nelson Our Address for service is: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street MELBOURNE, Australia 3000 Complete Specification for the invention entitled: ROAD VEHICLE TRAILER The following statement is a full description of this invention, including the best method of performing it known to applicant(s): 1 0804N ROAD VEHICLE TRAILIER This invention relates generally to a road vehicle trailer, and in particular to a vehicle transporting trailer.

The trailer is applicable for transporting cars and other four wheeled light road vehicles while being towed behind a towing vehicle, such as a truck or car, and it will be convenient to hereinafter disclose the invention in relation to that exemplary application. It is to be appreciated, however, that the invention is not limited to that application.

Cars and other four wheeled light road vehicles that are unregistered, unroadworthy, broken down or otherwise not legally drivable on roadways are typically transported with another vehicle. Where the vehicle to be transported is not towable, then it is usually loaded onto a trailer hitched or coupled to a towing vehicle, or hauled onto a tiltable load carrying tray of a cartage truck.

The construction of these trailers and trays can make loading and hauling of vehicles onto them difficult.

Moreover, in relation to the trailers, unless the transported 98". vehicle is well balanced on the trailer, then that trailer may sway or otherwise deviate uncontrollably during use, o. particularly during highway towing.

The trailers and cartage trucks are also relatively large, thus placing a high demand on storage space when not in use. In addition, particularly the cartage trucks, are an expensive capital purchase and are unlikely to be commercially economic for infrequent or occasional use.

An object of the present invention is to alleviate these disadvantages through the provision of a relatively simple trailer for transporting cars and other four wheeled light road vehicles.

With that in mind, the present invention provide trailer for transporting a four wheeled road G ehicle, including: spaced apart wheel assemblies upporting the trailer for rolling movement over gro each wheel assembly having at least one ground eni ng wheel rotatable about a rotation axis during rol j movement; a hitching assembly for coupling the trai to a toving vehicle; and, a load carrying structure nted on the wheel assemblies and constructed to S:.su: ingly receive an end part only of a road vehicle

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-3- With that in mind, the present invention provides a trailer for transporting a four wheeled road vehicle, including: spaced apart wheel assemblies supporting the trailer for travel over ground, each wheel assembly having at least one ground engaging wheel rotatable about a rotation axis, and each of the wheels being pivotable about a respective upright axis to enable wheel turning during trailer travel; a load carrying structure mounted on the wheel assemblies and constructed to supportingly receive an end part only of a road vehicle thereon, with a pair of wheels of the road vehicle remaining in rolling contact with the ground so that the road vehicle is supported by the trailer and ground for transportation; and, a hitching assembly for coupling the trailer to a towing vehicle, the hitching assembly including a hitching member connected to the load carrying structure and extending therefrom in a forward direction of trailer travel, the hitching member being connected to the load carrying structure independently of the mounting of the load carrying structure on the wheel assemblies, and being 15 connected for pivotal movement relative to the load carrying structure in directions side-to-side from a straight forward direction of trailer travel, and one or more steering members interconnecting the wheel assemblies and hitching member so that pivotal movement of the hitching member causes pivotal turning movement of the wheels and thus steering of the trailer during travel.

20 Preferably, the hitching member is elongate with opposite end regions.

One end region is pivotally connected to the load carrying structure while the other can be coupled to the towing vehicle.

Preferably, a pair of steering members are provided. Each steering member is preferably a rigid steering arm extending between and connected to the hitching member and a respective wheel assembly. Each wheel assembly preferably includes a stub axle unit to which the respective wheel is rotatably connected. Each stub axle is mounted for pivotal movement about the respective upright axis to enable wheel turning. Preferably, the steering arms are connected to the stub axle units for interconnecting the wheel assemblies and hitching member.

The hitching assembly is preferably releasably lockable to the load carrying structure in the straight forward direction of trailer travel. That in turn prevents steering of the trailer relative to the towing vehicle.

3a Preferably, the load carrying structure is connected to the wheel assemblies so as to be positioned between the wheels and at or adjacent a level of the wheel rotation axis. The arrangement is such that the load carrying structure is at a low level relative to the ground to facilitate loading and unloading of the transported road vehicle.

Preferably, the load carrying structure is movable toward the ground, while the trailer is coupled to the towing vehicle in order to facilitate loading and unloading of the transported vehicle.

In one embodiment, the load carrying structure includes a support frame on which the end part of the transported vehicle is received and supported. The structure also includes a ramp member rigidly connected to the support frame and extending downwardly therefrom toward the ground in a rearward direction, relative to the trailer towing direction. In this way, wheels at the supported end part of the transported vehicle can roll over the ramp member onto and off the support frame during loading and unloading, respectively. The hitching member preferably extends beneath and is pivotally connected to the support frame through a connection located beneath the support frame.

Each wheel assembly preferably includes a suspension mechanism mounting a respective wheel to the load carrying structure. The suspension mechanisms each include a respective stub axle unit, and a pair of control members connecting the stub axle unit to the load carrying structure for up and down movement relative thereto. Thus, wheel movement relative to the load carrying structure is permitted in response to ground conditions over which the trailer travels. In one embodiment, each pair of control members includes upper and lower control arms respectively positioned at least substantially at and below a level of the load carrying structure and projecting laterally therefrom to the stub axle unit. With this arrangement, the suspension mechanisms and wheels are located clear of the load carrying structure for unimpeded loading and unloading of the trailer.

Preferably, the hitching member has a rear end region connected to the load 4carrying structure and a forward end region which can be coupled to a towing vehicle. The hitching member selectively actuable, while coupled to the towing vehicle, to move the load carrying structure toward the ground to facilitate loading and unloading of the trailer, and held against actuation for trailer towing. Preferably, the hitching member includes a pair of elongate hitching member sections. Those sections are interconnected for selective relative movement to pivot the load carrying structure about the wheel rotation axis so that the load carrying structure tilts towards the ground for vehicle loading and unloading.

In one embodiment, the hitching member sections are interconnected for relative pivotal movement about an axis extending parallel to the wheel rotation axis to pivot the load carrying structure. Moreover those hitching member sections can be selectively held rigid against pivotal movement for trailer towing.

Preferably, each of the wheels are pivotable abou/ a respective upright axis to enable wheel turning a thus 2 V. steering of the trailer during travel. Wheel /turning is preferably controlled by the hitching ass ly which is connected to the lodd carrying structure r pivotal movement side-to-side from a position strai ahead of the load carrying structure, and one more steering members interconnect the wheels and tching assembly. As a result, pivotal movement of th hitching assembly causes pivotal turning movement of the wheels. The hitching assembly is preferably relea ly lockable to the load carrying structure o in the str 'ht ahead position for fixing the wheels in the straigh ahead position. That in turn prevents steering of th railer relative to a towing vehicle.

The following description refers to a preferred embodiment of the trailer of the present invention. To facilitate an understanding of the invention, reference is made in the description to the accompanying drawings where the trailer is illustrated in that preferred embodiment. It is to be understood that the trailer is not limited to the preferred embodiment as hereinafter described and as illustrated in the drawings.

4 In the drawings: 5 Fig. 1 is a side elevation of a trailer according to a preferred embodiment of the present invention, and showing loading/unloading of a vehicle; Fig. 2 is a plan view of the trailer of Fig. 1; and, Fig. 3 is an end elevation of a detailed part of the trailer of Fig. i.

Referring to the drawings, there is generally shown a vehicle transporting trailer i. The trailer 1 can be coupled to a towing vehicle (not shown) for transporting a four wheeled road ve'iicle V by towing in a forward direction A.

The trailer 1 includes a load carrying structure 2 on which an end part P (in this embodiment being a front part) o: the vehicle V can be loaded for support during transportation. As shwon, front wheels WF of the vehicle are positioned on the load carrying structure 2, whilst the rear wheels W R remain in rolling contact with ground G. It will be appreciated that the vehicle V may be reverse loaded onto the load carrying structure 2.

SThe load carrying structure 2 is of a rigid construction, and includes a support frame 3 on which the end part P of a transported vehicle V is received and supported.

e That frame 3 is elongate in a direction transverse of the eo trailer towing direction A. The frame is of a generally planar, skeletal construction and includes a pair (front and rear) of cross beams 4,5 extending in spaced apart relation transverse of the trailer towing direction A. Those cross beams 4,5 are parallel and spaced apart a distance selected to enable a pair of wheels W of the transported vehicle to span across the space but be at least partially cradled between them. In that way, the beams 4,5 tend to act as "chocks" inhibiting accidental rolling movement of the vehicle V relative to the trailer 1 during towing.

The support frame 3 includes connecting beams 6,7 extending between the cross beams 4,5 to rigidly secure them together to provide rigidity in the support frame 3.

Connecting beams 6 are located at end regions of the support frame 3 and extend between opposite ends of the crcss beams whilst at least two (as shown) connecting beams 7 a ce provided intermediate those cross beam ends.

Each connecting beam 6 projects from the ends of the 6 cross beams 4,5 outwardly, transversely of the trailer towing direction A, and provides a mounting region 8 spaced outwardly of the cross beams 4,5. This arrangement is achieved by constructing each connecting beam 6 as a pair of beam sections 9,10, each being angled outwardly from a respective cross beam and coming together at the mounting region 8.

The load carrying structure 2 further includes ramp means 11 connected to the support frame 3 and over which wheels W at the end part P of the transported vehicle V to be supported can roll during loading and unloading. The ramp means 11 is rigidly connected to the support frame 3 and is angled downwardly therefrom, in a rearward direction relative to the trailer towing direction A.

The ramp means 11 includes a ramp member 12 over which the transported vehicle wheels W can roll during loading and unloading. In one arrangement (as shown), a single ramp member 12 is provided and spans a transverse extent of the support frame 3 to accommodate both wheels W. That ramp member 12 may extend over substantially the entire transverse r o extent of the support frame 3. In an alternative arrangement (not shown), a pair of ramp members are provided, each being oloo positioned and spanning a transverse extent of the support frame 3 to accommodate a respective wheel W.

g The ramp member 12 includes a ramp plate 13 rigidly connected directly or indirectly to the rear cross beam 4.

Indirect connection (as shown) is through a ramp frame 14 on which the ramp plate 13 is mounted.

The load carrying structure 2 is constructed of any suitable material. In this embodiment, the support frame 3 and ramp means 11 are fabricated from metal, such as steel, bar and plate stock.

A pair of wheel assemblies 15 are mounted on the load carrying structure 2 for supporting the trailer 1 for rolling movement over the ground G. Each wheel assembly 15 is mounted adjacent a respective connecting beam 6 of the support frame 3. Each wheel assembly 15 includes a single ground engaging wheel 16 and a suspension mechanism 17 mounting the respective wheel 16 to the support frame 3.

The wheels 16 are rotatable about a rotation axis X which extends transversely of the trailer towing direction A when the wheels 16 are in a "straight ahead" position (as shown in full line in Fig. Moreover, the wheels 16 are mounted so that the rotation axis X is at a level just below the support frame 3. That relative relationship is generally maintained with the trailer 1 in its loaded and unloaded conditions.

The rotation axis X of the wheels 16 is also offset rearwardly of a longitudinal mid axis between the cross beams In this way, with the wheels W of a transported vehicle V received between the cross beams 4,5 there is a weight bias on the trailer 1 forwardly of the rotation axis X.

Each wheel 16 is of a conventional construction, including a hub 18 supporting a pneumatically inflated tyre 19.

The suspension mechanisms 17 are independant of each other and independantly mount the respective wheels 16 to the support frame 3.

Each suspension mechanism 17 includes a stub axle unit to which the wheel hub 18 is connected. Each stub axle unit 20 is of any suitable construction, well known to those 29, skilled in the relevant art.

Each suspension mechanism 17 also includes a pair of too, control members 21 connecting the respective stub axle unit ep to the support frame 3. These control members 21 include o upper and lower control arms 22,23 directly or indirectly interconnecting the stub axle unit 20 and the beams 4,5 of the support frame 3.

Each upper control arm 22 has an outer end region 24 connected to the stub axle unit 20 at a level above the support frame 3. and an inner end region 25 connected directly re or indirectly to at least one cross beam 4,5. Moreover, each upper control arm 22 is positioned at or below the level of the support frame 3 over the extent of that frame 3, but projects upwardly therefrom at the outer end region 24 beyond the transverse extent of the support frame 3. In this way, the arm 22 remains clear of the support frame 3 for unimpeded loading and unloading of the trailer 1.

In this embodiment, each upper control arm 22 is bifurcated, providing a pair of arm sections 26 extending from a common outer end region 24 to separate, spaced apart inner end regions 25. The inner end regions 25 are each connected directly or indirectly to a respective cross beam Moreover, each arm section 26 is located at an outside of a respective cross beam 4,5 so that the arm sections 26 extend transversely about the support frame 3 to the outer end region 24 located transversely outwardly of, and projecting upwardly from, the support frame 3. The arm sections 26 lie in a common plane except the outer end region 24 which projects perpendicularly upwardly from that plane.

Each lower control arm 23 has an outer end region 27 connected to the stub axle unit 20 at a level below the support frame 3 and an inner end region 28 connected directly or indirectly to at least one connecting beam 4,5. Each lower control arm 23 is provided beneath the level of the support frame 3 so as to again facilitate clear loading and unloading of the trailer i. Moreover, the inner end region 28 is connected at a position located transversely outwardly of the position at which the inner end region 25 of the associated upper control arm 22 is connected.

In this embodiment, each lower control arm 23 is also bifurcated, providing a pair of arm sections 29 extending from a common outer end region 27 to separate, spaced apart inner oo end regions 28. The inner end regions 28 are each connected directly or indirectly to an intermediate connecting beam 7.

The arm sections 29 lie in a common plane.

The upper and lower control arms 22,23 are connected at their inner and outer end regions 25,28,24,27 through any suitable pivotal connection well known by those skilled in the relevant art. In that regard, by way of example, the outer end regions 24,27 are pivotably connected to the stub axle units 20 through swivel joints 30, such as ball joints.

Further, by way of example, the inner end regions 25,28 are pivotably connected to the respective support frame beams through connection bolts (not shown), with suitable journals and/or bushings (not shown), the axes of pivot Y provided by the connection bolts extending parallel to the direction of trailer towing A.

Each suspension mechanism 17 further includes means 31 for damping pivotal movement of the control members 21, and thus the wheels 16, relative to the load carrying structure 2, during trailer use.

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9 In this embodiment, the damping means 31 includes at least one compression spring 32 acting directly or indirectly between the support frame 3 and each lower control arm 23. A single spring 32 is mounted between a respective end connecting beam 6, adjacent the mounting region 8 thereof, and a bearing plate 33, extending between the arm sections 29 of an underlying lower control arm 23, adjacent the outer end region 27.

The damping means 31 also includes at least one shock absorber 34 acting directly or indirectly between the support frame 3 and each upper control arm 22. A single shock absorber 34 is mounted between a respective end connecting beam 6, adjacent the mounting region 8, and a connection bracket 35 directly or indirectly connected to the upper control arm 22 adjacent the outer end region 24 thereof.

The trailer 1 further includes a hitching assembly 36 for coupling the trailer 1 to a towing vehicle. The hitching assembly 36 includes an elongate hitching member 37 projecting forwardly of the load carrying structure 2. That hitching member 37 has a rearward end region 38 connected to the load carrying structure 2 and a forward end region 39 which can be coupled to a towing vehicle.

The hitching member 37 is selectively actuable, while o o coupled to a towing vehicle, to achieve movement of the load carrying structure 2 toward the ground to facilitate loading and unloading. That movement is pivotal about the wheel rotation axis X, so that the ramp means 11 can be moved toward the ground G for vehicle loading and unloading, and away from the ground G for trailer towing.

The hitching member 37 includes a pair of hitching member sections 40,41, one rearward section 40 providing the rearward end region 38, and the other forward section 41 providing the forward end region 39. These hitching member sections 40,41 are interconnected for selective relative movement in order to achieve pivotal movement of the load carrying structure 2. To that end, the hitching member sections 40,41 are interconnected for relative pivotal movement about an axis x extending parallel to the wheel rotation axis X. Those sections 40,41 can, however, also be rigidly interconnected for trailer towing and otherwise when I tilting of the load carrying structure 2 is not required.

Thus, the hitching member sections 40,41 can relatively pivot between a non-tilt position (as shown in full line in Fig. 2) of the load carrying structure 2 in which the sections 40,41 are longitudinally aligned, and a tilted position (as shown in chain-dot line in Fig. 2) of the load carrying structure 2 in which the sections 40,41 are pivoted out of that alignment.

The hitching member sections 40,41 have overlapping regions 42, intermediate the rearward and forward end regions 38,39, and are pivotably interconnected in those overlapping regions 42. The overlapping region 42 of the forward section 41 is spaced from the forward end region 39 and incorporates an opposite end region 43 at which the section 41 is pivotably interconnected to the rearward section 40. The overlapping region 42 of the rearward section 40 is spaced from the rearward end region 38 and incorporates an opposite end region 44 at which the section 40 can be connected to the forward section 41 in order to provide rigid interconnection of the hitching member sections 40,41.

O. Pivotal interconnection of the hitching member sections 40,41 is provided by a pivot pin 45 extending through aligned apertures in the sections, in one embodiment. A connection pin is provided for removable insertion in aligned apertures in those sections, when the sections are longitudinally aligned, in order to rigidly interconnect the sections in the non-tilted position.

In one embodiment, the hitching member sections are biased into the tilted position of the load carrying structure to facilitate tilting of that structure, particularly when not loaded, upon disconnection of the sections, such as through S removal of the connection pin, for pivoting of those sections. However, that bias is overcome by the weight bias of a vehicle when loaded on the trailer, in this embodiment, so that the load carrying structure can return to its non-tilted position. The bias on the sections is resilient in one embodiment, and may include one or more biasing springs acting between the overlapping regions of the hitching member sections.

In one embodiment, the hitching sections are composed of metal, such as steel, sections.

The hitching assembly also includes a coupling unit mounted at the forward end region of the hitching member for coupling of the trailer to a towing vehicle. That coupling unit may be of any suitable construction well known to those skilled in the relevant art.

The wheels 16 are pivotable about a respective upright axis Z to achieve steering of the trailer 1 during towing.

That is achieved by connecting the stub axle units 20 to the outer end regions 24,27 of their respective control arms 22,23 for pivotal movement about such an axis Z. The swivel joints provide suitable connections.

Controlled steering of the wheels 16 is achieved through the trailer hitching assembly 36. To that end, the hitching member 37 is connected to the load carrying structure 2 for pivotal movement side-to-side (as shown in chain-dot line in Fig. 2) from a position projecting straight ahead (as shown in full line in Fig. 2) of the load carrying structure 2. In addition, one or more steering members 48 directly or indirectly interconnect the wheels 16 to the hitching member .i 37 so that pivotal movement of the hitching member 37 causes turning movement of the wheels 16.

The rearward end region 38 of the hitching member 37 is connected to the support frame 3 for pivotal movement of that member 37 within a horizontal plane during trailer towing.

.2 Thus, a connection 49 provides for pivotal movement about a vertical axis z during trailer towing. The connection 49 is located rearwardly of the longitudinal mid axis between the cross beams 4,5 of the support frame 3. Moreover, that connection 49 is beneath the support frame 3 so as to be clear of vehicles V loaded onto the trailer i.

The steering members 48 are rigid steering arms 50. A respective single steering arm 50 extends between the hitching member 37 and each wheel 16. Connection of the steering arms to the wheels 16 is through the stub axle units 20. The steering arms 50 are pivotably connected to the hitching member 37 and stub axle units 20 to enable movement therebetween as the hitching member 37 pivots.

Each steering arm 50 incorporates an adjustable tie rod mechanism 51 to enable adjustment of toe-in/toe-out of the wheels 16.

Pivotal movement of the hitching member 37 is limited in order to limit pivotal movement relative to the load carrying structure 2. That is achieved, through the provision of stop members 52 against which the hitching member 37 can abut. The stop members 52 are provided by a pair of stop plates 53 mounted on the load carrying structure 2, and are positioned to limit pivotal movement on respective sides of a straight ahead position of the hitching member 37.

The hitching member 37 is releasably lockable to the load carrying structure 2 in a straight ahead position. The hitching member 37 would typically be locked to the load carrying structure 2 when being towed unloaded since towing of the unloaded trailer 1 without locking of the hitching member 37 may result in uncontrolled movement of the load carrying structure 2 and wheel assemblies 15. Locking is achieved, by a locking pin 54 releasably insertable in aligned apertures provided in the hitching member 37 and load carrying structure 2.

In using a trailer i, according to a preferred •coo embodiment as outlined above, for transporting a vehicle V, the unloaded trailer 1 is initially coupled to a towing vehicle.

The connection pin 46 of the hitching member 37 is removed to cause the hitching member sections 40,41 to pivot under bias of the biasing spring so that the load carrying structure 2 pivots into its tilted position. In that position, a vehicle V to be transported can be partially loaded onto the trailer 1 by driving or hauling up the ramp member 12 until a pair of the vehicle wheels W roll onto the support frame 3. Either the front or rear wheels WFWR may be received on the support frame 3, depending on whether the front or rear parts P are to be supported for transporation. As those wheels W roll into a position between the cross beams 4,5, they exert a weight bias on the load carrying structure 2 causing that structure 2 to return pivot into its non-tilted position. The connection pin 46 can then be re-inserted to connect the hitching member sections 40,41 together.

The vehicle wheels W received on the load carrying structure 2 are cradled between the cross beams 4,5 and I I generally act to retain the vehicle V in towing connection with the trailer 1. However, additional connection may be achieved if necessary through tie-down cables or straps extending between the vehicle V and trailer i.

Finally, the locking pin 54 is removed to release the hitching member 37 for steering of the trailer wheels 16.

The trailer 1 as loaded with a vehicle V to be transported is generally towed as a conventional trailer.

However, instead of entirely supporting the vehicle V as with a conventional trailer, the trailer 1 of the present invention provides a bogie-like support for one end of the vehicle V.

Thus, the vehicle V is supported at one end by the trailer 1 and at the other end by existing vehicle wheels WR. In addition, unlike conventional trailers, the wheels 16 of the trailer 1 will be steered through the hitching member 37 as the towing vehicle steers.

Unloading of the transported vehicle is the reverse of the above outlined loading procedure.

The trailer of the present invention provides good towing control, even at relatively high speeds as might be experienced during highway travel.

The trailer is of a relatively simple construction and °o ~low capital cost.

The trailer of the present invention is relatively small .2 and therefore is easy to manoeuvre both by itself and when being towed. In addition, the small trailer facilitates storage when not in use by reducing required storage space.

Finally, it will be appreciated that various modifications and/or additions may be made to the trailer without departing from the aimbit of the invention as defined in the claims appended hereto.

Claims (24)

1. A trailer for transporting a four wheeled road vehicle, including: spaced apart wheel assemblies supporting the .railer for travel over ground, each wheel assembly having at least one ground engaging wheel rotatable about a rotation axis, and each of the wheels being pivotable about a respective upright axis to enable wheel turning during trailer travel; a load carrying structure mounted on the wheel assemblies and constructed to supportingly receive an end part only of a road vehicle thereon, with a pair of wheels of the road vehicle remaining in rolling contact with the ground so that the road vehicle is supported by the trailer and ground for transportation; and, a hitching assembly for coupling the trailer to a towing vehicle, the hitching assembly including a hitching member connected to the load carrying structure and extending therefrom in a forward direction of trailer travel, the hitching member being connected to the load carrying structure independently of the mounting of the load carrying structure on the wheel 15 assemblies, and being connected for pivotal movement relative to the load carrying structure in directions side-to-side from a straight forward direction of o trailer travel, and one or more steering members interconnecting the wheel assemblies and hitching member so that pivotal movement of the hitching member causes pivotal turning movement of the wheels and thus steering of the S 20 trailer during travel.

2. A trailer as claimed in claim 1, wherein the hitching member is elongate with opposite end regions, one of which is pivotally connected to the load carrying structure and the other of which can be coupled to the towing vehicle.

3. A trailer as claimed in claim 1 or 2, wherein a pair of steering members are provided, each steering member is a rigid steering arm extending between and connected to the hitching member and a respective wheel assembly.

4. A trailer as claimed in any preceding claim, wherein each wheel assembly includes a stub axle unit to which the respective wheel is rotatably connected, each stub axle being mounted for pivotal movement about the respective upright axis to enable wheel turning. A trailer as claimed in claim 4, wherein the steering members are connected to the stub axle units for interconnecting the wheel assemblies and hitching member.

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6. A trailer as claimed in any preceding claim, wherein the hitching assembly is releasably lockable to the load carrying structure in the straight forward direction of trailer travel for fixing the wheels in that direction thereby to prevent steering of the trailer relative to the towing vehicle.

7. A trailer as claimed in any preceding claim, wherein the load carrying structure is connected to the wheel assemblies so as to be positioned between the wheels and at or adjacent a level of the wheel rotation axis, whereby the load carrying structure is at a low level relative to the ground to facilitate loading and unloading of the transported road vehicle.

8. A trailer as claimed in any preceding claim, wherein the load carrying structure is movable toward the ground, while the trailer is coupled to the towing vehicle in order to facilitate loading and unloading of the transportea road vehicle.

9. A trailer as claimed in any preceding claim, wherein the loac carrying o structure includes two cross beams extending in spaced apart relation transverse of the trailer towing direction, the spacing of the cross beams being such as to enable a pair of wheels of the transported road vehicle to span across the space and be at least partially cradled between them.

A trailer as claimed in claim 9, wherein the hitching member is pivotally connected to the load carrying structure rearwardly of an axis extending parallel S 20 to and equi-spaced between the two cross beams.

11. A trailer as claimed in any preceding claim, wherein the load carrying structure includes a support frame on which the end part of the transported road vehicle is received and supported, and a ramp member rigidly connected to the support frame and extending downwardly therefrom toward the ground in a rearward direction, relative to the trailer towing direction, so that wheels at the supported end part of the transported vehicle can roll over the ramp member onto and off the support frame during loading and unloading, respectively.

12. A trailer as claimed in claim 11, wherein the hitching member extends beneath the support frame and is pivotally connected thereto through a connection located beneath the support frame. 2. C

13. A trailer as claimed in any preceding claim, wherein the load carrying structure is mounted on the wheel assemblies so that, when a transported vehicle end part is supported thereon, there is a weight bias on the trailer forwardly of the wheel rotation axis, in the trailer towing direction. a o o r r e i "r i

14. A trailer as claimed in any one of claims 1 to 3 or any one of claimnis 6 to 13 when appended thereto, wherein each wheel assembly includes a suspension mechanism mouning a respective wheel to the load carrying structure, the suspension mechanism including a stub axle unit to which the wheel is rotatably connected and a pair of control members connecting the stub axle unit to the load carrying structure for up and down movement relative thereto, and thereby permit wheel movement relative to the load carrying structure in response to ground conditions over which the trailer travels.

A trailer as claimed in claim 14, wherein the steering members are connected to the stub axle units for interconnecting the wheel assemblies and hitching member.

16. A trailer as claimed in claim 14 or 15, wherein each pair of control members includes upper and lower control arms respectively positioned at least substantially at and below a level of the load carrying structure and projecting laterally therefrom to the stub axle unit so that the suspension mechanisms and wheels are located clear of the load carrying structure for unimpeded loading and unloading of the trailer.

17. A trailer as claimed in claim 16, wherein each control arm is bifurcated, providing a pair of arm sections extending from a common outer end region located laterally of the load carrying structure and to which the stub axle unit is connected, to separate spaced apart inner end regions individually connected to the load carrying structure.

18. A trailer as claimed in claim 17, wherein the inner end regions of each control arm are pivotably connected to the load carrying structure for pivotable movement about axes extending parallel to the direction of trailer towing.

19. A trailer as claimed in any preceding claim, wherein the hitching member has a rearward end region connected to the load carrying structure and a forward end region which can be coupled to a towing vehicle, the hitching member being selectively actuable, while coupled to the towing vehicle, to move the load carrying structure toward the ground to facilitate loading and unloading of the trailer, and held against actuation for trailer towing.

A trailer as claimed in claim 19, wherein the hitching member includes a pair of elongate hitching member sections interconnected for selective relative movernment to pivot the load carrying structure about the wheel rotation axis so that the load carrying structure tilts towards the ground for vehicle loading and unloading.

21. A trailer as claimed in claim 20, wherein the hitching member sections are interconnected for relative pivotal movement about an axis extending parallel to the wheel rotation axis to pivot the load carrying structure, the hitching member sections being held rigid against pivotal movement for trailer towing.

22. A trailer as claimed in claim 22, wherein the hitching member sections have longitudinally overlapping regions intermediate the rearward and forward end regions, and are pivotably interconnected in the overlapping regions, the hitching member sections being rigidly interconnected in longitudinal alignment for trailer towing and released for relative pivotal movement out of alignment to pivot the load carrying structure.

23. A trailer as claimed in any one of claims 20 to 23, wherein the hitching member sections are biased so as to relatively move to pivot the load carrying structure about the wheel rotation axis, that bias being overcome by a weight bias of a transported road vehicle when loaded onto the trailer.

24. A trailer as claimed in claim 23, wherein the hitching assembly includes one or more resilient biasing springs acting between the hitching member sections and providing the bias to relatively move the hitching member sections. A trailer for transporting a four wheeled road vehicle, substantially as hereinbefore described with reference to what is shown in the accompanying drawings. DATED: 3 April 1996 PHILLPS ORMONDE FITZPATRICK Attorneys for: GRAEME McCAMM NELSON ADSTRACT A trailer for transporting a four wheeled road vehicle while being towed behind a towing vehicle. The trailer includes spaced apart wheel assemblies supporting the trailer for rolling movement over ground each wheel assembly (15) having at least one ground engaging wheel (16) rotatable about a rotation axis during rolling movement. A hitching assembly (36) couples the trailer to a towing vehicle. A load carrying structure is mounted on the wheel assemblies (15) and constructed to supportingly receive an end part only of a road vehicle A pair of wheels of the road vehicle remain in rolling contact with the ground G so that the road vehicle (V) is supported by the trailer and ground for transportation. 00