GB1563796A - Trailers for transporting vehicles - Google Patents

Description

(54) IMPROVEMENTS IN TRAILERS FOR TRANSPORTING VEHICLES (71) 1, TERENCE ARTHUR PHILPOTT, a British subject, of 17, Queensway, Ringwood, Hampshire, England, do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to trailers for use in the transport of vehicles, and primarily for the recovery of crashed or otherwise disabled road vehicles such as automobiles and the like.

An automobile which is disabled to the extent that it cannot be simply towed on all of its road wheels is usually recovered by a recovery vehicle or break-down truck which tows the disabled vehicle with its damaged front or rear end raised by a crane, or jacked up on a trailer or dolly unit. Such recovery techniques can, however, only be employed if the disabled vehicle can still be supported and towed along on one of its own sets of wheels, i.e. on its front or rear wheels. The nature or extent of the damage often precludes raising and towing employing a crane, and even when a crane can be used, it often causes additional damage to the disabled vehicle.The use of a trailer or dolly unit can likewise damage the disabled vehicle, and, moreover, since the unit, including its road wheels has to be rolled under the disabled vehicle from the front or the rear, it can only be employed if there is sufficient ground clearance beneath the disabled vehicle, or after lifting the vehicle.

If the nature or extent of the damage is such that the disabled vehicle cannot be raised for towing, or cannot be supported and moved on one of its own sets of wheels, it is customary to bodily transport the vehicle on a trailer. However, the disabled vehicle must be dragged, for example winched, onto and off the trailer, which often causes additional damage to the vehicle.

It is an object of the present invention to provide a trailer which overcomes the aforementioned disadvantages of prior recovery techniques.

According to the present invention, there is provided a trailer for transporting a vehicle, including an elongate vehiclesupport device dimensioned to be insertable transversely of, and beneath, a vehicle to be transported, lifting means operable to raise the support device and vehicle located thereabove, and a rolling chassis unit including chassis members locatable beneath the support device when so raised, the support device and chassis members being mutually cooperable upon subsequent lowering of the support device, to support the support device and vehicle located thereabove from the chassis unit.

In one embodiment of the invention, the elongate vehicle-support device comprises two rigid tubes, for example steel or other metal tubes, the length of each of which approximates, but is greater than, the maximum track of vehicles intended to be transported by the trailer, and one or more interconnecting members releasably attachable to at least one of the tubes, and cooperable with both tubes, to hold them in parallel spaced relation, the or each interconnecting member being relatively shallow. The mutual spacing of the parallel tubes is determined by the or each interconnecting member, and is less than the maximum external diameter of the wheels of vehicles intended to be transported.

The or each interconnecting member which, in use, is positioned beneath the vehicle between the near side and off side wheels of the set of wheels at one end of the vehicle, is provided with lifting means which, in its retracted or inoperative position is also relatively shallow. The lifting means may, for example, comprise an air bag or the like which collapses into a relatively flat condition when deflated, and, when inflated, raises the assembled tubes and the or each interconnecting member, and therefore a vehicle supported thereon, for example by approximately 1 foot.

In this embodiment, the rolling chassis unit comprises a chassis frame which is basically generally U-shaped in plan, the base of the U comprising a cross-member connected or connectable to a tow bar or bracket. The side limbs of the U comprise side members which extend longitudinally fore and aft in the direction of movement of the chassis unit, outboard of which are mounted road wheels carried by suspension units secured to the side and/or cross members. The transverse separation of the side members approximates, but is less than, the length of the tubes, and the length of each side member approximates, but is greater than, the said mutual separation of the tubes. The side members are provided with means for positively releasably cooperating with, and supporting, the outer ends of the tubes.

In operation, the or each interconnecting member, with its air bag deflated, is slid beneath the offside and near side wheels at the end of the vehicle which is to be raised. The tubes are then slid beneath the vehicle, transversely thereof and into cooperation with the or each interconnecting member, so that the outer ends of the tubes project outboard of and on opposite sides of the offside and nearside wheels. The air bags are then inflated, raising the interconnecting member and the tubes interconnected thereby, and since the tubes, adjacent the outer ends thereof, cooperate directly or indirectly with the vehicle wheels, the end of the vehicle is likewise raised by its wheels, until the outer ends of the tubes are raised by approximately one foot.The chassis unit is then backed around the raised end of the vehicle, until the chassis side members lie on opposite sides of the vehicle beneath the outer ends of the tubes. The air bags are then deflated, thus lowering the outer ends of the tubes into engagement with the cooperating and supporting means of the side members. It will be apparent that, by further deflating the air bags, the tubes, and therefore the end of the vehicle carried thereby, will be supported on the chassis unit, and the vehicle, in this condition, may be towed along on the trailer, with the wheels at the other end of the vehicle running on the road.

However, if required, the other end of the vehicle may be similarly supported on a further or rear support device and chassis unit which may be connected to the first mentioned or front chassis unit by longitudinally extending and adjustable side members.

Since, as will be apparent, the or each chassis unit remains in a fixed position relative to the vehicle being transported during towing, the road wheels of at least the front chassis unit will be steerable, for example by means of a linkage connected to the tow bar or bracket which will be pivotally connected to the crossmember.

From the foregoing, it will be apparent that a trailer embodying this invention may readily be assembled to a disabled vehicle without having to physically displace the vehicle on its own road wheels during loading, whilst, during towing, the vehicle is supported on its own road wheels from the trailer.

In order that the invention may be more readily understood reference will now be made to the accompanying drawings, in which: Figure 1 is an exploded diagrammatic plan view of one embodiment of the trailer, with parts broken away for clarity: Figure 2 is a side view of one of the interconnecting members, showing its associated lifting means in its operative or extended position; Figure 3 is a side view of one of the side members of the front chassis unit; Figures 4 and 5 are fragmentary plan views of a modified tow bar arrangement; Figure 6 is a plan view of a modified elongate vehicle support device; Figure 7 is a fragmentary view, sectioned on the line 7-7 of Figure 9; Figure 8 is a side view, similar to Figure 2, of one of the modified interconnecting members; and Figure 9 is a side view similar to Figure 3, of one of the side members of a chassis unit, modified to accept the modified support device of Figures 6 to 8.

Wth reference to Figure 1, the trailer includes front and rear trailer units 1 and 2 of basically similar design and construction. Each trailer unit comprises a rolling chassis unit 3 which is generally U-shaped in plan, built up from a cross-member 3a, and a pair of longitudinally extending, generally horizontal side members 3b. A longitudinal central member 3c is also provided. A pair of wheels 4 is mounted, in tandem, outboard of each side member 3b, by suitable suspension units (not shown), such as "FLEXITOR" (Registered Trade Mark) suspension units, secured beneath each side member 3b. The wheels of the front chassis unit are steerable via a linkage indicated generally at 5, coupled to a rigid tow bar 6, pivotally connected at 6a to the cross-member 3a, whereas the wheels of the rear chassis unit are not steerable, and no tow bar is provided.

Each chassis unit 3 is of robust, rigid construction, and may, for example, be fabricated by welding from mild steel tubing and/or plate, such as 14 guage mild steel. For example, the cross-member 3a may be rectangular section, 4" by 4" preformed or fabricated tubing, whilst each side member 3b may be basically rectangular section, 3" by 3" tubing, with the side falls thereof extended upwardly above the upper wall 3d of the rectangular section as shown in Figure 3, to form a pair of side flanges, an outer one of which is indicated at 3e in Figure 3, the outer side flanges 3e of both side members 3b, as well as the inner side flanges 3f, being shown in Figure 1. The inner flange 3f, but not the outer flange 3e, of each side member 3b, is formed with cooperating and supporting means comprising four semi-circular, upwardly opening cut-outs 3g.As an alternative, the side members 3b may be formed rectangular section 3" by 4" tubing, in which case the previously mentioned cut-outs will be provided in the inner side wall of the tubing, and the upper wall of the tubing will be correspondingly slotted. The central member 3c may be fabricated from upper and lower plates 12" wide interconnected by side walls 4" high, the upper plate and side walls being slotted and cut-out respectively, as shown at 3h in Figure 1, to provide channels in alignment with, and of the same cross sectional dimensions as, the cut-outs 3g in the side members 3b.

Although a single central member 3c is shown, it may alternatively take the form of a pair of transversely spaced-apart and longitudinally extending members, similar to the side members 3b.

The mutual separation between the inner side walls of the side members 3b will determine the maximum track of disabled vehicles, for example automobiles, which the trailer units will accommodate, and this spacing may, for example, be approximately 5ft. 10".

Each chassis unit 3 is intended to be used in combination with an elongate vehicle-support device, comprising a pair of transverse tubes 7 releasably interconnected by a pair of interconnecting members 8. Each tube 7 is dimensioned to sit in, and be supported and positively located by, selected aligned cut-outs in the side and central chassis members. Each tube 7 may, for example, be 14 guage, 1+" or 2" external diameter, mild steel tubing. Each tube 7 will be slightly shorter than the spacing between the outer flanges 3e of the side members 3b, for example approximately 6ft. 4" long, so that the tube will be received between the flanges 3e, and transverse sliding movement of the tube relative to the chassis unit will be prevented by these flanges.

Each interconnecting member 8 is formed from a plate, for example a jf" thick mild steel plate which, as viewed in Figure 1, may be approximately 12" wide and 20" long. As will be apparent from Figure 2, the longitudinal ends 8a of the plate are turned downwardly and inwardly so as to embrace two pairs of tube 9, the internal diameter of each of which is slightly greater than the external diameter of the tubes 7, so that the tubes 9 will slidably receive the tubes 7.The plate is welded to the tubes 9, and to depending transverse plate portions 8b and longitudinal plate portions 8c the plate portions 8b and 8c defining, with the underside of the plate, a downwardly opening rectangular cavity 8e. The inter-axial spacing of the tubes 9 corresponds to that of the aligned cut-outs in the side and central chassis members, and, as viewed in Figure 2, the inter-axial spacing between the two outer-most tubes 9 may be approximately 18", whilst the spacing between the two inner-most tubes 9, i.e. the tubes adjacent the transverse plate portions 8b, may be approximately 12".

The cavity 8e contains lifting means comprising an inflatable air bag 10 formed from a reinforced natural or synthetic rubber, such as neoprene. In its fully inflated position, as shown in Figure 2, the air bag may be generally cubic, 10" wide, by 10" long, by 10" high. The upper wall of the air bag is bonded or otherwise secured within the cavity 8e to the underside of the plate of the interconnecting member, whilst a base plate 10a is secured to the lower wall of the air bag. When deflated, the air bag is collapsed within the cavity 8e, and the base plate 10a lies against the underside of the inturned ends 8a, and may be held thereagainst by suitable manually-releasable retaining means.

It will be apparent that, in this condition, the interconnecting member 8 is relatively shallow, its overall height, between the upper surface of the plate and the lower surface of the base plate 10a, being 3" or less.

Each air bag 10 will be provided with an appropriate connection (not shown), by which compressed air, for example at a pressure of approximately 20 pounds per square inch, may be supplied to the air bag to inflate the latter, and through which air may be vented during deflation of the air bag. If desired, the two air bags associated with each trailer unit may be interconnected or interconnectable, or all four air bags may be interconnected or interconnectable, and connected or connectable to a common supply line for compressed air.

The front and rear chassis units may be interconnected by means of a pair of removable longitudinally extending side members, fragments of which are shown at 11 in Figures 1 and 3. These members 11 may comprise rectangular section mild steel tubing, dimensioned to telescopically slid ably fit within the open ends of the side members 3b of both chassis units.

Means, such as cross pins or bolts (not shown) may be provided in order to positively lock the side members 11 and 3b in a required telescopically adjusted position, depending upon the wheel base of an automobile to be recovered. The members 11 may be articulated about horizontal axes, for example, adjacent the front trailer unit, as indicated at 11a in Figure 3.

In use of the trailer hereinbefore described and illustrated to transport and recover a disabled automobile, the operation of the front trailer unit will be described, since the operation of the rear trailer unit is virtually identical. Firstly, with reference to Figure 1, the two interconnecting members 8, separated from both of the tubes 7, and with their air bags deflated and the base plates 10a retracted against the inturned ends 8a, are slid underneath that end of the disabled automobile which is to be raised, to positions in which they lie inboard of, and directly adjacent, the near side and offside automobile wheels respectively.One of the tubes 7 is then slid beneath the automobile from one side thereof, adjacent the front of the wheel, for example of the near side wheel, through one of the tubes 9 of the interconnecting member adjacent that wheel, beneath the automobile, through the corresponding tube 9 of the interconnecting member adjacent the other wheel, i.e. the offside wheel, and out from beneath the vehicle on the other side thereof, adjacent the front of that wheel.. The second tube 7 is then slid beneath the automobile in a similar manner, behind the wheels, and through other of the tubes 9, for example as shown in Figure 1. Means (not shown) may be provided to releasably lock the interconnecting members 8 to the tubes 7 in their adjusted positions.If the automobile to be recovered has relatively large diameter wheels (for example, a 14" wheel as shown at 12 in Figure 3), then the tubes 7 are passed through the outer tubes 9 in the interconnecting members 8 as shown in Figure 1 so that the spacing between the tubes 7 will approximate the external radius of the wheels. If the automobile to be recovered has relatively small diameter wheels (for example a 10" wheel as shown at 13 in Figure 3), then the tubes 7 are passed through the inner-most tubes 9 adjacent the plate portions 8b. With the tubes 7 and interconnecting members 8 assembled as described, the wheels will straddle the portions of the tubes 7 outboard of the members 8, but with the tips of the tubes 7 projecting outboard of the wheels. The position of one such wheel 12 is indicated in outline in Figure 1.

It will be apparent that the assembly and positioning of the tubes 7 and inter connecting members 8 beneath the dis abled automobile can be achieved without disturbing the automobile, even if the sus pension or wheels thereof have been damaged and have collapsed, and the ground clearance beneath the automobile has been somewhat reduced, due to the shallow nature of the tubes 7 and inter connecting members 8. The air bags 10 of both members 8 are then connected to a suitable source of compressed air, for example a compressed air cylinder or compressor carried by the recovery vehicle which is to tow the trailer, and the air bags are inflated, thus causing the interconnect ing members 8 to be raised, raising the tubes 7 which in turn lift the automobile wheels which are cradled between the outer ends of the tubes.The tubes 7 are prefer ably raised by a minimum of approxi mately 10" by the air bags, correspond ingly raising the end of the automobile, whereafter the front chassis unit 3, posi tioned as shown in Figure 1, is rolled back towards the disabled automobile so that the chassis side members 3b pass around and along opposite sides of the automobile and beneath the projecting tips of the outer end portions of the tubes, whilst the central member 3c passes beneath the raised end of the automobile. When the appropriate cut-outs in the side and central members have been approximately aligned beneath the tubes 7, the air bags 10 are deflated, lowering the tubes into the cut outs, so that the raised end of the auto mobile is then supported, via the tubes 7, from the chassis unit 3. The air bags are fully deflated, and the base plates 10a retracted against, and preferably clipped beneath, the inturned ends 8a of the interconnecting members to provide adequate ground clearance beneath the base plate 10a when the trailer is towed.

The wheels or other parts of the raised end of the automobile may be shackled or otherwise suitably anchored to the tubes 7 or chassis unit, and the tubes themselves may be suitably anchored within their cut-outs in the side and/or central chassis members.

When an automobile is to be transported, which has a relatively wide track, corresponding to the maximum track which will be accommodated by the trailer unit, the automobile wheels will be disposed directly adjacent the side members 3b, so that a major proportion of the weight of the raised end of the automobile will be transferred directly to the side members 3b, with a minimum bending load being imposed upon the tubes 7. However, with an automobile having a narrow track, the interconnecting members 8 will be located closer together on the tubes 7 and nearer to the central member 3c than is shown in Figure 1, so that a progressively larger proportion of the automobile weight will be carried by the central member.The minimum track which will be accommodated by the trailer unit is determined by the transverse spacing between the interconnecting members 8, which spacing must be sufficient to accommodate the central chassis member 3c.

The positions which different diameter automobile wheels will assume when cradled by differently positioned tubes 7 is shown in Figure 3.

The automobile may be towed with one of its ends, i.e. its front or rear end, sup ported on the front or left hand trailer unit, coupled by the tow bar 6 to the towing or recovery vehicle. The other end of the automobile may be supported on its own set of wheels if still operative, in which event, the rear or right hand trailer unit need not be employed. However, if this is not the case, the automobile may be transported bodily by assembling the rear trailer unit to the other -end of the automobile as previously described with reference to the front trailer unit, in which event, the front and rear chassis units are interconnected by inserting opposite ends of the side members 11 into the hollow side members 3b of the two units, and anchoring these ends in an adjusted position, dependent upon the wheel base of the disabled automobile.The hinges 1 la accommodate relative movement between the two trailer units due, for example, to uneveness or changes in levels in road surface.

The transported and recovered automobile may be removed from one or both trailer units by simply reversing the aforementioned operation.

From the foregoing it will be seen that there is provided a particularly advantageous construction of trailer, which may be employed to raise, support and transport one or both ends of a disabled vehicle as required. Loading and unloading of the trailer may be effected without the need for any movement of the disabled vehicle on its own wheels, and the vehicle will, in most cases, be supported on its own wheels or suspension units during lifting, transporting and lowering, so that additional damage caused by handling the disabled vehicle which is avoided or minimised.

Since the raising and lowering of the disabled vehicle is effected by air bags or the like, as distinct from more conventional types of mechanical jacks, the interconnecting members 8, when the air bags are deflated, are relatively shallow, facilitating their insertion beneath disabled vehicles which have reduced ground clearance due to damaged or collapsed tyres, wheels or suspension units. Provided that a ground clearance of approximately 3" exists, the interconnecting members 8 and associated tubes 7 may be fitted without first having to raise the vehicle.The interconnecting members 8 themselves present upwardly directed expansive surfaces, which may be employed to directly engage and support the disabled vehicle if the latter cannot be supported on the tubes 7 by its own wheels, for example, if one or more of the suspension units or wheels are collapsed or missing, or the vehicle chassis is badly distorted.

Since the interconnecting members 8 and air bags 10 are located entirely inboard of the vehicle wheels, the distance by which the tubes 7 must project transversely outboard of the disabled vehicle is reduced to a minimum, and the overall width of the chassis unit may also be minimised. For example, the track of the front trailer unit may be approximately 7ft., whilst that of the rear trailer unit may be approximately 6ft. 6", the additional track of the front trailer unit being required to provide adequate clearance between the steerable wheels 4 and the chassis side members 3b. The tubes 7 and interconnecting members 8 may be inserted and assembled beneath the disabled vehicle from either side thereof.The trailer unit may thus be assembled to, and dis-assembled from, a vehicle, even when relatively little clearance exists between one or both sides of the vehicle and an obstruction or obstructions.

The modified tow bar arrangement shown in Figures 4 and 5 eliminates the neceissity for articulating the side members 11 as indicated at lla in Figure 3. In this modification, a box or rectangular crosssection tow bar 6 is articulated about a horizontal axis by means of a pivotal connection 6b, adjacent the pivotal connection 6a of the tow bar to the cross-member 3a of the front chassis unit 1. Between the pivotal connections 6a and 6b, the tow bar is apertured at 6c and 6d. When the tow bar 6 is straight, i.e. normal to the cross member 3a, the aperture 6c is vertically aligned with a corresponding aperture 14a in a plate 14 fixed to the cross member 3a. A box-section slide member 15, apertured at 15a surrounds, and is slidable along, the tow bar 6.The steering linkage (5 in Figure 1) will be connected either to the tow bar 6 or to a drop arm connected to the connection 6a which will, in that event, turn with the tow bar.

When the trailer, whether laden or unladen, includes interconnected front and rear trailer units, the slide member is spaced from the pivotal connection 6b as shown in Figure 4, and is preferably locked in this position by a pin or the like (not shown) extending through the aperture 15a and an underlying aperture in the tow bar.

In this position, the tow bar is able to pivot about the vertical axis of the connection 6a to steer the trailer unit, and is also able to pivot about the horizontal axis of the connection 6b to accommodate relative movement between the trailer and towing vehicle due, for example, to uneveness or changes in level in the road surface.

When the trailer consists of only the front trailer unit, and this unit is laden, the slide member 15 is slid to the position shown in Figure 5, and locked in place by the locking pin (not shown), which is passed through the apertures 15a and 6d.

In this position, the slide member surrounds and locks the connection 6b against pivotal movement which would otherwise allow the single trailer unit to roll about a transverse axis during towing.

When the trailer consists of only the front trailer unit, and is unladen, it is additionally necessary to lock the steering in a central position to prevent the trailer unit from weaving from side to side during towing. This is achieved by sliding the slide member 15 further towards the connection 6a, beneath (or over) the plate 14, until the apertures 15a 14a and 6c are vertically aligned, and then inserting the locking pin therein.

Figures 6 to 9 illustrate a modified elongate vehicle-support device which is capable of accommodating a wider range of wheel diameters than that shown in the embodiment of Figures 1 to 3. In this modification, each interconnecting member 8 incorporates only one pair of tubes 9, which are mutually spaced apart by a greater distance than the tubes 9 of the outer pair shown in Figure 2, so as to accommodate wheels of a larger maximum diameter, for example 16" wheels. Although the mutual spacing between the tubes 7 is not adjustable, an adjustable assembly is detachably mounted on the two ends of the tubes 7 outboard of each interconnecting member 8.

Each adjustable assembly includes a bridge plate 16, for example a flat steel bar, to or adjacent opposite ends of which are welded short lengths, for example 9" lengths, of tube 16a. The tubes 16a are slidable over the outboard ends of the tubes 7 as shown in Figures 6 and 7 and, when the free ends of the tubes 16a butt against the side of the interconnecting member 8, the tips of the tubes 7 project outboard of the bridge plate 16 for engagement in a single pair of cut-outs 3g in the associated side member 3b as shown in Figure 9.

An adjustable hollow bearer 17 is rotatably mounted on each tube 16a. Each bearer 17 includes a steel plate skin 17a, end walls 17b and 17c, and an intermediate wall 17d, provided with aligned apertures 17g for accommodating a tube 16a.

On opposite sides of the axis of the apertures 17g, the walls 17b and 17d are provided with pairs of aligned apertures 17e and 17f alignable, selectively, with an aperture 16b in the bridge plate 16. As will be apparent from Figures 7, 8 and 9, the axis of the tube-receiving apertures 17g is offset from the transverse centre line of the bearer 17 so that the bearer is eccentrically mounted on its associated tube 16a.

In use, the tubes 7 and interconnecting members 8 of the elongate vehicle-support device shown in Figures 6 to 9 are assembled to a disabled vehicle in the same way as described with reference to Figures 1 to 3. However, after assembly but before inflating the air bags 10 to raise the vehicle, the previously described adjustable arrangement is adjusted and assembled to the outboard ends of the tubes 7. In particular, if a vehicle having relatively small diameter wheels, for example 10" wheels, is to be raised, each bearer 17 is fitted onto its associated tube 16a, rotated to the position shown in Figure 9, and a locking pin 18 is inserted into the aligned apertures 17e and 16b to lock the bearer against rotation, whereafter the tubes 16a are slid over the respective outboard ends of the tubes 7 so that the bearers extend beneath the vehicle wheel 13. The support device and vehicle are then raised by inflating the air bags 10, and lowered onto a front or rear trailer unit in the manner previously described, whilst the wheels are cradled between and supported by the pairs of bearers 17.

If the vehicle to be raised has intermediate diameter wheels, for example 14" wheels, before the adjustable assembly is assembled to the outboard ends of the tubes 7, the pins 18 are removed and each bearer 17 is rotated about its associated tube 16a from the position shown in Figure 9, through 180 , so that the bearers are effectively spaced further apart, and the pins 18 are then inserted into their respective apertures 16b and underlying pairs of apertures 17f, to lock the bearers against rotation.

When it is desired to raise a vehicle having a maximum diameter wheels, for example 16" wheels, the bearers 17 are removed entirely from the tubes 16a, and the bridge plate and associated tubes 16a alone are slid on to the outboard ends of the tubes 7. Thus when the vehicle is raised, the wheel rests directly on and is cradled between the tubes 16a.

This modification not only simplifies the construction of the interconnecting members 8, but also enables the support device to accommodate a wider range of wheel sizes without altering the separation between the tubes 7.

Furthermore, the provision of the bridge plates 16 reduces the spreading loads to which the outboard ends of the tubes 7 would otherwise be subjected whilst a vehicle is being raised or lowered.

In addition, as will be apparent from Figure 8, since only one pair of tubes 9 is provided and these tubes are spaced apart by a significantly greater distance than are the tubes shown in Figure 2, the air bag 10 can be made longer in the fore and aft direction of the trailer unit than that shown in Figure 2 and is therefore more stable when supporting the support device. In addition, the air bag is able to fit more securely into the internal contours of the downwardly opening cavity 8a, in the interconnecting member 8 as indicated in broken lines in Figure 8.

Although not shown in this Figure, a base plate equivalent to the plate 10a shown in Figure 2, and associated retaining means, may be provided.

It will be understood that various modifications may be made without departing from the scope of the present invention as defined in the appended claims.

For example, the size, shape, configuration, number, and/or constructional materials of the components of the or each trailer unit may be modified, depending upon the type and size of vehicle, or range of vehicles, to be transported. More or less than two interconnecting members or their equivalent may be provided, and they may each embody a plurality of air bags or equivalent; or may embody other types of lifting means or jacks. The interconnecting members may be permanently connected, but preferably adjustably attached, to one of the tubes 7 or equivalent. Means may be provided, locatable outboard of the wheels of the vehicle to be transported, for lifting, or assisting in lifting, the tubes 7 or equivalent.

The central chassis member 3c may be omitted, although this is required if threewheeled vehicles are to be transported.

Alternatively, more than one central member may be provided, in which event, the central members may be adjustably mounted on the cross-member 3a. The cross-member 3a may be designed to be adjustable in length, or the side members may be adjustable along the former, so that the mutual separation of the side members 3b may be varied to allow them to lie directly adjacent the wheels of vehicles of differing tracks.

Although the trailer is primarily intended to transport disabled vehicles, this is not essential, and it may be employed, for example by the police, to remove illegally parked vehicles or the like, which cannot conveniently or readily be driven under their own power.

Under certain conditions, after lifting a disabled vehicle on the assembled tubes 7, interconnecting members 8 and air bags 10, the tubes 7 may be inaccessible to one or both chassis units without first moving the vehicle to a more convenient position.

For this reason, supplemental manoevering trolleys may be provided, two per trailer unit, which are placed one beneath each interconnecting member 8, adjacent regions of the tubes 7, and a wheel of the raised vehicle. The air bags 10 are then deflated, lowering the vehicle's wheels, and the tubes 7, onto the trolleys, and the vehicle is manoervered on the trolleys to a more accessible position, whereafter the air bags are reinflated, and the trolleys are removed and replaced by one or more chassis units.

WHAT I CLAIM IS:- 1. A trailer for transporting a vehicle, including an elongate vehicle-support device dimensioned to be insertable transversely of, and beneath, a vehicle to be transported, lifting means operable to raise the support device and vehicle located thereabove, and a rolling chassis unit including chassis members locatable beneath the support device when so raised, the support device and chassis members being mutually cooperable upon subsequent lowering of the support device, to support the support device and vehicle located thereabove from the chassis unit.

2. A trailer as claimed in claim 1, wherein the elongate vehicle-support device comprises two rigid support tubes, the length of each of which approximates, but

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

Claims (17)

**WARNING** start of CLMS field may overlap end of DESC **. 14" wheels, before the adjustable assembly is assembled to the outboard ends of the tubes 7, the pins 18 are removed and each bearer 17 is rotated about its associated tube 16a from the position shown in Figure 9, through 180 , so that the bearers are effectively spaced further apart, and the pins 18 are then inserted into their respective apertures 16b and underlying pairs of apertures 17f, to lock the bearers against rotation. When it is desired to raise a vehicle having a maximum diameter wheels, for example 16" wheels, the bearers 17 are removed entirely from the tubes 16a, and the bridge plate and associated tubes 16a alone are slid on to the outboard ends of the tubes 7. Thus when the vehicle is raised, the wheel rests directly on and is cradled between the tubes 16a. This modification not only simplifies the construction of the interconnecting members 8, but also enables the support device to accommodate a wider range of wheel sizes without altering the separation between the tubes 7. Furthermore, the provision of the bridge plates 16 reduces the spreading loads to which the outboard ends of the tubes 7 would otherwise be subjected whilst a vehicle is being raised or lowered. In addition, as will be apparent from Figure 8, since only one pair of tubes 9 is provided and these tubes are spaced apart by a significantly greater distance than are the tubes shown in Figure 2, the air bag 10 can be made longer in the fore and aft direction of the trailer unit than that shown in Figure 2 and is therefore more stable when supporting the support device. In addition, the air bag is able to fit more securely into the internal contours of the downwardly opening cavity 8a, in the interconnecting member 8 as indicated in broken lines in Figure 8. Although not shown in this Figure, a base plate equivalent to the plate 10a shown in Figure 2, and associated retaining means, may be provided. It will be understood that various modifications may be made without departing from the scope of the present invention as defined in the appended claims. For example, the size, shape, configuration, number, and/or constructional materials of the components of the or each trailer unit may be modified, depending upon the type and size of vehicle, or range of vehicles, to be transported. More or less than two interconnecting members or their equivalent may be provided, and they may each embody a plurality of air bags or equivalent; or may embody other types of lifting means or jacks. The interconnecting members may be permanently connected, but preferably adjustably attached, to one of the tubes 7 or equivalent. Means may be provided, locatable outboard of the wheels of the vehicle to be transported, for lifting, or assisting in lifting, the tubes 7 or equivalent. The central chassis member 3c may be omitted, although this is required if threewheeled vehicles are to be transported. Alternatively, more than one central member may be provided, in which event, the central members may be adjustably mounted on the cross-member 3a. The cross-member 3a may be designed to be adjustable in length, or the side members may be adjustable along the former, so that the mutual separation of the side members 3b may be varied to allow them to lie directly adjacent the wheels of vehicles of differing tracks. Although the trailer is primarily intended to transport disabled vehicles, this is not essential, and it may be employed, for example by the police, to remove illegally parked vehicles or the like, which cannot conveniently or readily be driven under their own power. Under certain conditions, after lifting a disabled vehicle on the assembled tubes 7, interconnecting members 8 and air bags 10, the tubes 7 may be inaccessible to one or both chassis units without first moving the vehicle to a more convenient position. For this reason, supplemental manoevering trolleys may be provided, two per trailer unit, which are placed one beneath each interconnecting member 8, adjacent regions of the tubes 7, and a wheel of the raised vehicle. The air bags 10 are then deflated, lowering the vehicle's wheels, and the tubes 7, onto the trolleys, and the vehicle is manoervered on the trolleys to a more accessible position, whereafter the air bags are reinflated, and the trolleys are removed and replaced by one or more chassis units. WHAT I CLAIM IS:-

1. A trailer for transporting a vehicle, including an elongate vehicle-support device dimensioned to be insertable transversely of, and beneath, a vehicle to be transported, lifting means operable to raise the support device and vehicle located thereabove, and a rolling chassis unit including chassis members locatable beneath the support device when so raised, the support device and chassis members being mutually cooperable upon subsequent lowering of the support device, to support the support device and vehicle located thereabove from the chassis unit.

2. A trailer as claimed in claim 1, wherein the elongate vehicle-support device comprises two rigid support tubes, the length of each of which approximates, but

is greater than, the maximum track of vehicles intended to be transported by the trailer, and one or more relatively shallow interconnecting members releasably attachable to at least one of the support tubes, and cooperable with both tubes remote from their ends, to hold the tubes in parallel spaced relation, the chassis unit being cooperable with the ends of the tubes to support the support device.

3. A trailer as claimed in claim 2, wherein the depth of the or each interconnecting member is less than twice the external cross-sectional dimension of the support tubes.

4. A trailer as claimed in claim 2 or 3, wherein the or each interconnecting member includes mutually spaced fixed tubular sleeves within which the support tubes are slidably locatable, the depth of the or each interconnecting member approximating the external cross-sectional dimension of the tubular sleeves.

5. A trailer as claimed in claim 2, 3 or 4, wherein the or each interconnecting member is provided with lifting means which, in its retracted or inoperative position, is also relatively shallow.

6. A trailer as claimed in claim 5, wherein the or each interconnecting member is formed with a downwardly opening cavity, the associated lifting means, when in its retracted or inoperative position, being at least partially retracted within the cavity.

7. A trailer as claimed in claim 6, wherein the lifting means of the or each interconnecting member comprises an air bag which collapses into a relatively flat condition within its associated cavity when deflated, and, when inflated, is operable to raise the assembled tubes and the or each interconnecting member, and therefore a vehicle when supported thereon.

8. A trailer as claimed in any of claims 2 to 7, wherein the rolling chassis unit comprises a chassis frame which is basically generally U-shaped in plan, the base of the U comprising a cross-member and the side limbs of the U comprising side members which extend generally longitudinally fore and aft in the direction of movement of the chassis unit, outboard of which are mounted road wheels carried by suspension units secured to the side and/or cross members, the transverse separation of the side members approximating, but being less than, the length of the support tubes, and the length of each side member approximating, but being greater than, the separation of the support tubes when interconnected by the or each interconnecting member, the side members being provided with means to positively releasably cooperate with, and support, the outer ends of the support tubes.

9. A trailer as claimed in claim 8, wherein the road wheels of the chassis unit are steerable by a rigid tow bar pivotally connected to the cross-member.

10. A trailer as claimed in any of claims 2 to 9, wherein the wheels of a vehicle to be raised are intended to be cradled between the support tubes adjacent the opposite ends thereof, and wherein the or each interconnecting member is cooperable with the support tubes so as to permit adjustment of the spacing between the support tubes to accommodate vehicle wheels of different diameters.

11. A trailer as claimed in any of claims 2 to 9, wherein the wheels of a vehicle to be raised are intended to be cradled between pairs of spaced intermediate support means of adjustable arrangements assembled to, and supportable by, the support tubes adjacent the opposite ends thereof, the spacing between the intermediate support means of each pair being adjustable to accommodate vehicle wheels of differing diameters.

12. A trailer as claimed in claim 11, wherein the intermediate support means comprises a bearer member eccentrically mounted one adjacent each end of each support tube, the bearer members of each pair being rotatable about their associated support tubes to adjust their mutual spacing, means being provided to releasably lock the bearer members in their adjusted positions.

13. A trailer as claimed in claim 12, wherein each adjustable arrangement includes a pair of fixed, mutually spaced tubular bosses rigidly interconnected by a bridging member, the bearer members of a pair being rotatably movable one on each of said tubular bosses, and being releasably lockable in their adjusted positions to the bridging member, the tubular bosses, with the bearer members mounted thereon, being slidable over adjacent ends of the support tubes and supportable by the latter when the support tubes and the or each interconnecting member are assembled together.

14. A trailer as claimed in any preceding claim, which includes two of said chassis units and associated vehicle-support devices, operable to support opposite ends of a vehicle to be transported, the trailer further includes side members arranged to releasably and telescopically interconnect the two chassis units.

15. A trailer constructed substantially as hereinbefore described with reference to Figures 1 to 3 of the accompanying drawings.

16. A trailer as claimed in claim 15, modified substantially as hereinbefore described with reference to Figure 4 and 5, of the accompanying drawings.

17. A trailer as claimed in claim 15 or 16, modified substantially as hereinbefore described with reference to Figures 6 to 9 of the accompanying drawings.