AU2009200341A1 - Trailer - Google Patents

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicant (s) Colron Industries Pty Ltd Invention Title: TRAILER The following statement is a full description of this invention, including the best method for performing it known to me/us: P79833.AU PalSetFing Application 2009-1-30.doc (B) - 2 TRAILER Field of the Invention The present invention relates to a trailer and 5 especially to a trailer which can be widened by increasing the distance between wheels provided on respective lateral sides of the trailer. Background of the Invention 10 Trailers, such as full trailers, semi trailers and low loaders, are often used to transport loads on roads. There is an established need for trailers capable of carrying wide loads. A disadvantage of wide trailers is that even when unladen their width can be inconvenient 15 causing difficulty in parking or negotiating narrow roads. A solution to this problem which has previously been offered is to provide a trailer having a width which may be varied so that the trailer may be used in a wider configuration when a greater width is required to 20 accommodate a load and may be used in a narrower configuration when the greater width is not required. Two types of variable width trailers have previously been provided: deck widening trailers, in which a load supporting deck of the trailer may be varied in width 25 without altering the wheel configuration, and; suspension widening (sometimes called axle-widening) trailers in which the wheels on respective lateral sides of the trailer may be moved apart in the lateral direction to increase the width of the trailer. A benefit of 30 suspension-widening trailers over deck-widening trailers in which the wheel configuration is not variable is that greater stability can be provided in the wider configuration due to the increased lateral width between the wheels on respective lateral sides of the trailer. 35 In suspension-widening trailers a driving mechanism, such as one or more hydraulic cylinders, is typically provided in order to facilitate widening or narrowing of N:\Brisbane\Cases\Paten79000-79999\P79833.AU\Spec s\P79833.AU Specification 2009-1-13.doc 30/01109 -3 the trailer. The widening or narrowing operation may therefore easily be performed by an operator, for example by using controls located on a suitable control panel. In order to avoid undue wear or damage to tires and/or 5 suspension components widening or narrowing operations of suspension-widening trailers should be performed with the trailer standing on a flat, smooth surface. Summary of the Invention 10 According to the present invention there is provided a trailer comprising a trailer body, at least one wheel provided on a first lateral side thereof and at least one wheel provided on a second lateral side thereof, wherein the distance between the wheels, in a transverse direction 15 of the trailer can be varied between a first smaller distance and a second greater distance, and wherein the trailer further comprises a lifting mechanism operable to lift at least part of the trailer body in order to reduce the weight of the trailer borne by the wheels. 20 The trailer may comprise more than one lifting mechanism. Preferably the one or more lifting mechanisms are operable to lift at least part of the trailer body so that substantially none of the weight of the trailer is borne 25 by the wheels. Preferably the one or more lifting mechanisms are operable to lift at least a rear part of the trailer body in order to reduce the weight of the trailer borne by wheels located at the rearmost half of the trailer. 30 Preferably the one or more lifting mechanisms are operable to lift at least part of the trailer body so that substantially none of the weight of the trailer is borne by wheels located at the rearmost half of the trailer. Preferably the one or more lifting mechanisms are 35 operable to lift at least part of the trailer body so that at least some of the wheels of the trailer are lifted clear of the ground. N:\Brisbane\Cases\Patent\79000-79999\P79833.AU\Specis\P79833.AU Specificaton 2009-1-13.doc 30101/09 Preferably the trailer body comprises a central spine, a first lateral side portion to which the at least one wheel provided on the first lateral side of the trailer body is mounted, and a second lateral side portion 5 to which the at least one wheel provided on the second lateral side of the trailer body is mounted. In an embodiment the lateral distance between the at least one wheel mounted to the first lateral side portion and the at least one wheel mounted to the second lateral side portion 10 may be varied by varying the distance between the first and second lateral side portions. In an embodiment one or more forcing mechanisms may be provided to force the first and second lateral side portions towards each other or away from each other. Respective first and second forcing 15 mechanisms may be provided to force the respective first and second lateral side portions towards and/or away from the central spine. Preferably the lifting mechanism is attached to the central spine. 20 Alternatively or additionally, one or more lifting mechanisms may be provided attached to at least one of the first and second lateral side portions. In such an embodiment one or more of the lifting mechanisms may comprise a ground engaging portion adapted to facilitate 25 lateral movement relative to the ground. The ground engaging portion preferably comprises roller mechanism, and may comprise one or more wheels, castors and/or rollers, although in a variation an alternative such as a skid or ski arrangement could be used. 30 Alternatively or additionally, one or more support legs which do not form part of lifting mechanisms may be provided attached to at least one of the first and second lateral side portions. Such support legs may enhance stability of the trailer when it is lifted. The or each 35 support leg may be provided with a restriction mechanism to allow extension thereof but restrict inadvertent retraction thereof under load. The restriction mechanism N:\Brisbane\Cases\Patent\79000-7999P7983.AU\Specis\P79833.AU Specification 2009-1-13.doc 30/01109 - 5 may comprise a ratchet mechanism. The or each support leg may be extended (eg, under power, under gravity, or manually) as or when the trailer body is lifted, and be retained in its extended position to provide support to a 5 lifted trailer. The or each support leg may comprise a ground engaging portion adapted to facilitate lateral movement relative to the ground. The ground engaging portion preferably comprises a roller mechanism, and may comprise one or more wheels, castors and/or rollers, 10 although in a variation an alternative such as a skid or ski arrangement could be used. Preferably the central spine defines a space therein and at least part of the lifting mechanism is accommodated within the space. 15 Preferably the lifting mechanism comprises at least one extendable member extendable downwardly from the trailer body in order to engage the ground. Preferably the at least one extendable member is extendable downwardly from the central spine in order to 20 engage the ground. Preferably the at least one extendable member comprises a ground engaging foot. Preferably the lifting mechanism or mechanisms comprise at least two ground engaging portions, spaced 25 apart in the lateral direction of the trailer in order to provide a required degree of lateral stability to the trailer when lifted. Preferably at least one extendable member is elongate and comprises a ground engaging foot at a part 30 thereof which is distal from the trailer body. Preferably the lifting member comprises a guide portion for guiding the at least one extendable member. Preferably the guide portion comprises a tubular guide member which cooperates with the extendable member 35 in a telescoping arrangement. Preferably at least one lifting mechanism is provided at the rearmost half of the trailer. N:\Brisbane\Cases\Patent\79000-79999\P79833.AU\Specis\79833 AU Specification 2009-1-13 doc 30/01/09 - 6 Preferably the lifting mechanism comprises a driving mechanism to drive the at least one extendable member. Preferably the driving mechanism comprises at least one of: an electric motor; a hydraulic piston; a pneumatic s piston; an internal combustion engine. Preferably the trailer is elongate and has a front and a rear. Preferably the trailer comprises a plurality of sets of wheels, each set comprising two or more substantially 10 coaxial wheels, and the sets being spaced apart along the trailer in a direction of elongation of the trailer. Preferably, at least part of the lifting mechanism is located more rearwardly, on the trailer, than at least one of the sets of wheels. 15 Preferably, at least one extendable member of at least one lifting mechanism, the extendable member being extendable downwardly from the trailer body in order to engage the ground, is located more rearwardly, on the trailer, than at least one of the sets of wheels. 20 According to a second aspect of the present invention there is provided a method of operating a trailer which comprises a trailer body, at least one wheel provided on a first lateral side thereof and at least one wheel provided on a second lateral side thereof, wherein the distance 25 between the wheels, in a transverse direction of the trailer can be varied between a first smaller distance and a second greater distance, the method comprising the steps of: operating a lifting mechanism to lift at least part 30 of the trailer body to reduce the weight of the trailer borne by at least one wheel provided on a first lateral side thereof and at least one wheel provided on a second lateral side thereof; adjusting the distance, in a transverse direction of 35 the trailer, between at least one wheel provided on the first lateral side of the trailer body and at least one wheel provided on a second lateral side of the trailer N:\Brisbane\Cases\Patent\79000-79999P79833.AU\Specis\P79833.AU Specification 2009-1-13 doc30/01/09 -7 body; and operating the lifting mechanism to lower said at least part of the trailer body. Preferably the trailer body comprises a central 5 spine, a first lateral side portion to which the at least one wheel provided on the first lateral side of the trailer body is mounted, and a second lateral side portion to which the at least one wheel provided on the second lateral side of the trailer body is mounted, and the step 10 of adjusting the distance, in a transverse direction of the trailer, between at least one wheel provided on the first lateral side of the trailer body and at least one wheel provided on a second lateral side of the trailer body comprises adjusting the distance, in a transverse 15 direction of the trailer, between the first lateral side portion and the second lateral side portion. Preferably the step of operating the lifting mechanism to lift at least part of the trailer body to reduce the weight of the trailer borne by at least one 20 wheel provided on a first lateral side thereof and at least one wheel provided on a second lateral side thereof comprises operating the lifting mechanism to lift at least one wheel provided on a first lateral side of the trailer body and at least one wheel provided on a second lateral 25 side of the trailer body substantially clear of a surface on which the trailer stands. According to a third aspect of the present invention there is provided a method of modifying a trailer which 30 comprises a trailer body, at least one wheel provided on a first lateral side thereof and at least one wheel provided on a second lateral side thereof, wherein the distance between the wheels, in a transverse direction of the trailer can be varied between a first smaller distance and 35 a second greater distance, the method comprising fitting to the trailer body a lifting mechanism operable to lift at least part of the trailer body in order to reduce the N:\Brisbane\Cases\Patent\79000-79999\P79833.AU\Specis\79833.AU Specification 2009-1-13.doc 30/01/09 - 8 weight of the trailer borne by the wheels. It will be appreciated that features set out in relation to the first aspect may disclose features and/or 5 steps applicable to the second and third aspects. Brief Description of the Drawings Embodiments of the invention will now be described, by way of example only, with reference to the accompanying 10 drawings in which: FIG 1. is a perspective view from below and rear of part of a trailer, in accordance with an embodiment of an aspect of the present invention, in which the wheels are in a narrower configuration and a lifting mechanism is in 15 a non-operative position; FIG.2 is a perspective view from the rear corresponding to FIG. 1; FIG. 3 is a perspective view from below and rear of the trailer of FIG. 1 with the wheels in a narrower 20 configuration and the lifting mechanism in an operative position; FIG. 4 is a perspective view from the rear corresponding to FIG. 3; FIG. 5 is a perspective view from below and the rear 25 of the trailer of FIG. 1 with the wheels in a wider configuration and the lifting mechanism in an operative position; FIG. 6 is a perspective view from the rear corresponding to FIG. 5; 30 FIG. 7 is a perspective view from below and rear of the trailer of FIG. 1 with the wheels in a wider configuration and the lifting mechanism in a non-operative position; FIG. 8 is a perspective view from the rear 35 corresponding to FIG. 7; FIG. 9 is a perspective view from the rear, side and below of a part of a central spine of the trailer of FIG. N:\Brisbane\Cases\Petent\79000-799 \P798 .AU\Specis\P79833 AU Specificalion 2009-1-13.doc 30/01/09 -9 1 and providing an enlarged view of the region where the lifting mechanism is provided; FIG. 10 is a view corresponding to the view of FIG. 9 in which a side wall of the central spine is omitted in 5 order to reveal interior detail; FIG. 11 is a transverse cross-sectional view on XI-XI of FIG. 9; FIG. 12 is a side view corresponding to FIG. 10; FIG. 13 is a schematic top view illustrating the 10 lifting mechanism of FIGS. 9 to 12 in situ; and FIG. 14 is a perspective view corresponding to the view of FIG. 9 but showing the lifting mechanism in an operative position. 15 Description of the Preferred Embodiments With reference to FIGS. 1 to 8 a trailer in accordance with an embodiment of an aspect of the present invention is generally designated by reference numeral 1. The trailer 1 comprises a central spine 20 which may be 20 regarded as at least part of a chassis of the trailer 1. First and second side portions 30, 40 respectively, of the trailer 1 are mounted to the central spine 20. The first side portion 30 is provided with first to fourth first side wheels 31A, 31B, 31C, 31D. It will be appreciated 25 that in the illustrated embodiment each of the first to fourth first-side wheels 31A, 31B, 31C, 31D is provided as one of a pair of neighbouring coaxial wheels. For simplicity and clarity only one wheel of each pair is provided with a reference numeral herein. It will be 30 appreciated that each first-side wheel 31A, 31B, 31C, 31D may be a single wheel (without a neighbouring coaxial wheel), may be provided as one of a pair of neighbouring coaxial wheels, or may be provided as one of a set of three or more neighbouring coaxial wheels provided on the 35 first lateral side of the trailer 1. The first to fourth first-side wheels 31A, 31B, 31C, 31D are mounted to the first side portion 30 of the trailer via suitable N:\Brisbane\Cases\Patent\790079999\P79833 AU\Specia\P79833.AU Specification 2009-1-13.doc 30/01/09 - 10 suspension component and axles (not shown in FIG. 1). The trailer 1 further comprises first to fourth second-side wheels 41A, 41B, 41C, 41D each mounted via suitable suspension components and axles to the second side portion 5 40 of the trailer 1. As with the corresponding first-side wheels 31A, 31B, 31C, 31D the first to fourth second-side wheels 41A, 41B, 41C, 41D are, in the illustrated embodiment, provided as respective wheels of first to fourth pairs of neighbouring coaxial wheels, and the 10 comments in this regard made above in relation to the first to fourth first-side wheels also apply to the first to fourth second-side wheels. As illustrated in FIG. 1 the first second-side wheel 41A is mounted to the second side portion 40 of the 15 trailer 1 by suspension components including a corresponding damper 44A and wheel mounting 45A. Similarly the second second-side wheel 42B is mounted to the second side portion 40 of the trailer 1 by a corresponding damper 44B and wheel mounting 45B. It will 20 be appreciated that corresponding suspension components are provided for the other wheels in this embodiment although, of course, other suspension componentry could be used. The trailer 1 is a suspension-widening trailer and the first and second side portions 30, 40 along with the 25 corresponding first-side and second-side wheels may be moved laterally between a narrower configuration (as illustrated in FIGS. 1 to 4) and a wider configuration (as illustrated in FIGS. 5 to 8). It will be appreciated that the wheels and suspension componentry mounted to the 30 respective first and second side portions 30, 40 move with the respective first and second side portions 30, 40. The trailer 1 is provided with a first-side driving mechanism which in this embodiment is in the form of first-side hydraulic cylinder 32 which is mounted between 35 the central spine 20 and a first-side mounting 33 provided on the first side portion 30. The trailer 1 further comprises a second-side driving mechanism which in this N:\Brisbane\Cases\Patent\79000-79999\P79833.AU\Specis\P79833 AU Specfi-caton 2009-1-13 doc 30/01M9 - 11 embodiment is in the form of a second-side hydraulic cylinder 42 which is mounted between the central spine 20 and a second-side mounting 43 provided on the second side portion 40. When the first- and second-side cylinders 32, 5 42 are in their retracted state (as illustrated in FIGS. 1 and 3) the wheels are in a narrower configuration. When the first- and second-side cylinders 32, 42 are extended, by extension of respective piston rods 32A, 42A the wheels are in a wider configuration (as illustrated in FIGS. 5 to 10 8). The first- and second-side pistons 32, 42 are operable by a suitable hydraulic control system which can be operated by a user of the trailer 1. It will be appreciated that driving mechanisms other than hydraulic pistons could be used if desired. 15 The trailer 1 further comprises at least one lifting mechanism, generally designated 50 (see, for example, FIGS. 10 to 13). In the embodiment of FIGS. 1 to 8 the lifting mechanism comprises first and second ground-engaging feet 20 52A, 52B mounted on respective extendable legs 53A, 53B. Figures 1,2,7 and 8 illustrate the lifting mechanism in a first configuration in which the feet 52A, 52B are raised (and may be considered to be in an inoperative configuration) so that they are clear of the ground (not 25 shown). Figures 3, 4, 5 and 6 illustrate the lifting mechanism 50 in a configuration in which the feet 52A, 52B are lowered so that they engage the ground so that the lifting mechanism 50 lifts the spine 20 in order to raise at least some of the wheels 31A, 31B, 31C, 31D, 41A, 41B, 30 41C, 41D off of the ground, or at least reduce the weight of the trailer which is borne by the wheels. The lifting mechanism 50 will be described in more detail, with reference to FIGS. 9 to 14, in due course. It will be appreciated that FIGS. 1 to 8 illustrate a 35 sequential operation of the trailer 1. FIGS. 1 and 2 show an initial state in which the trailer is in a narrow configuration and the lifting N:\Brisbane\Cass\Pstent\79O-79999\P79833 AU\Specas\P79833 AU Specification 2009-1-13.doc 30/01/09 - 12 mechanism 50 is in a non-operative position. In this configuration the trailer 1 may be operated as a relatively narrow trailer. When it is desired to widen the trailer, the trailer 1 is brought to rest and the 5 lifting mechanism 50 is operated to the configuration illustrated in FIGS. 3 and 4 in which the feet 52A, 52B are lowered and the wheels 31A to 31D, 41A to 41D are lifted clear of the surface on which the trailer stands. The trailer is then widened by an amount corresponding to io distance W shown in FIG. 5. In this embodiment the widening operation is performed by operation of the first and second-side cylinders 32, 42 to move the first and second side portions 30, 40 laterally outwards relative to the central spine 20. It will be appreciated that because 15 the wheels have been lifted clear of the ground the widening operation is facilitated. That is, less force is required in order to widen the trailer than would be required if lifting mechanism were absent or inoperative and the weight of the trailer were borne by the wheels in 20 the normal manner. Furthermore, the likelihood of damage to tires or suspension components is reduced. Further, it will be appreciated that, since the wheels do not engage the surface during the widening operation, the widening operation may be performed when the trailer 1 is standing 25 on an irregular surface (for example a surface which includes corrugations or one or more stepped road boundaries such as kerbs) or which might otherwise offer an inconvenient amount of resistance to lateral movement of the wheels (such as a surface constituted by particles 30 which might build up against a lateral side of a wheel during lateral movement thereof). It will be appreciated that, in a variation, the lifting mechanism may be operated so that the trailer 1 is lifted and so that the weight borne by the wheels is 35 reduced, but so that the wheels remain in contact with the ground albeit bearing less of the weight of the trailer than when the lifting mechanism is inoperative. Under N:\Brisbane\Cases\Patent\79000-79999\P79833 ALSpecis\P79833AU Specification 2009-1-13.doc 30/01/09 - 13 these circumstances it will be appreciated that the widening operation is facilitated compared to the circumstances where the lifting mechanism is absent or inoperative. Although it is currently preferred that the s lifting mechanism lift the wheels clear of the ground, provision of a trailer or method of operation in which the lifting mechanism operates to reduce the weight borne by the wheels without lifting them clear of the ground may nonetheless have utility. 10 FIGS. 7 and 8 illustrate the trailer 1 with the wheels in the wider configuration, and with the feet 52A, 52B retracted so that the widened trailer has been lowered to stand upon its wheels. That is, the lifting mechanism 50 has been operated to return to its non-operative 15 position. In the wider configuration the widened trailer may now be loaded with a desired cargo and/or driven away in the widened configuration. It will be appreciated that the lifting mechanism 50 may be structured and driven in any of a number of 20 suitable ways. However, an embodiment is described in more detail with reference to FIGS. 9 to 14, by way of illustration. With reference to FIGS. 9 to 14 at least part of the lifting mechanism 50 is located within the central spine 25 20 of the trailer 1. The central spine 20 of the trailer 1 comprises a first lateral side panel 21A, a second lateral side panel 21B, a top panel 22 and a bottom panel 23 which together create a metal box section member which provides stiffness to the trailer 1. The spine 20 is thus 30 provided with an elongate space therein. The central spine 20 is further provided with a box section stiffening member 25 which is welded to the inner surface of the top plate 22 and which extends along a central axis thereof. A laterally oriented reinforcing 35 plate 26 is provided at or adjacent an end of the box section stiffening member 25 which is closer to the lifting mechanism 50. N:\Brisbane\Case\Patent\7900-79999\P79833 AUASpecis\P79833 AU Specification 2009-1-13 doc 30i01A09 - 14 The central spine 20 further comprises a number of laterally projecting supports 24 each of which has a first side portion 24A extending laterally, perpendicular to the central spine in a first direction and a second side s portion 24B extending laterally, perpendicular to the central spine, towards the second side of the trailer. The lateral supports may support the first and second side portions 30, 40 of the trailer. The lifting mechanism 50 is mounted to the central 10 spine 20. In the illustrated embodiment the feet 52A, 52B are located substantially flush with the bottom panel 23 when the lifting mechanism is in its non-operative configuration. The extendible legs 53A, 53B extend through apertures 27A, 27B in the bottom panel of the 15 central spine. Each of the extendible legs 53A, 53B is extendible from a respective leg guide of which one, 54A, is shown. Each extendible leg 53A, 53B and its respective leg guide 54A may be regarded as a telescopic leg arrangement which allows extension of the respective leg 20 53A, in this embodiment perpendicular to a central spine 30. Each extendible leg 53A, 53B is driven by a driving arrangement which in this embodiment is an arrangement which comprises a hydraulic cylinder 55A, 55B of the lifting mechanism 50. The two driving arrangements are 25 substantially identical in construction and therefore only the driving arrangement which comprises a first-side hydraulic cylinder 55A of the lifting mechanism 50 will be described in detail, although it will be appreciated that (in this embodiment) the driving arrangement which 30 comprises second-side hydraulic cylinder 55B of the lifting mechanism 50 substantially corresponds. The first-side hydraulic cylinder 55A of the lifting mechanism 50 is attached at an upper end thereof to a mounting bar 59A, which extends along the underside of the 35 top panel 22 between the lateral reinforcing plate 26 and the first-side leg guide 54A, via a mounting 68A provided at the top of the first-side hydraulic cylinder 55A. A N:\Brisbane\Cases\Patent\79O0-79999\P79833 AUASpecis\P79833.AU Specification 2009-1-13.dOc 30/01/09 - 15 piston rod 56A of the first-side hydraulic cylinder 55A extends from a bottom end of the first-side hydraulic cylinder 55A. The piston rod 56A is attached to the first side foot 52A, via a foot mounting bar 51A, by a 5 bifurcated mounting attachment 57A of the piston rod 56A. The bifurcated mounting attachment 57A is connected to the mounting bar 51A by a fixing pin 58A. The foot mounting bar 51A is substantially rigidly attached to the first side foot 52A and to the first-side extendible leg 53A. 10 The first-side foot 52A, extendible leg 53A and foot mounting bar 51A may be fixed to each other by welding or any other suitable type of attachment. The first-side hydraulic cylinder 55A of the lifting mechanism 50 may be operated from a suitable hydraulics 15 control panel (not shown) as discussed above. It will be appreciated that, in use, the combination of first-side leg guide 54A and first-side extendible leg 53A restricts the movement of the first side foot 52A to a substantially vertical direction perpendicular to the long 20 axis of the central spine 2. The first-side hydraulic cylinder 55A of the lifting mechanism 50 can be operated to extend or retract the first-side extendible leg 53A (and thereby lower or raise the first-side foot 52A relative to the central spine 20). In practice it is 25 intended that the first- and second-side feet 52A, 53A be operated in tandem. It will be appreciated that the first and second side extendible legs 53A, 53B and corresponding feet 52A, 52B can therefore be operated to provide a lifting mechanism as described above in relation to FIGS. 30 1 to 8. Of course, it will be appreciated that many different structures and driving mechanisms could be incorporated as alternatives in order to provide a suitable lifting mechanism. For example pneumatic cylinders, electric (or other) motors coupled to linear 35 actuators or rack and pinion mechanisms or the like could be used. Although in the illustrated embodiment a lifting N: \risbane\Cases\Patent\79000-79999P79833.ALASpecis\P79833.AU Specification 2009-1-13.doc 30/01109 - 16 mechanism is provided at substantially only one point along the length of the spine, it will be appreciated that two or more lifting mechanisms spaced along the length of the spine could be provided. Further, it will be 5 appreciated that although the lifting mechanism 50 is illustrated and described as comprising two extendable legs (and corresponding mechanisms) operating in tandem, these could equally be regarded as being two lifting mechanisms. 10 The preferred embodiment therefore provides a trailer 1 including one or more lifting mechanisms 50 which can lift the trailer body in order to reduce the weight borne by the wheels (preferably lifting the wheels and therefore reducing the weight borne by them to zero) during a is widening or narrowing operation of the trailer. It will further be appreciated that in the above described embodiment a first-side foot and a second-side foot are provided in order to provide lateral stability for the trailer when the body is lifted. However, in a variation 20 a single foot (which could be lowered and/or raised by a single hydraulic cylinder or other driving mechanism) could be provided. It is preferred that such a single foot would be sufficiently wide, in the lateral direction of the trailer, to provide adequate stability and/or that 25 additional supports (such as support legs, described below) be provided to provide adequate lateral stability for a lifted trailer. It will be appreciated that providing the lifting mechanism(s) attached to the spine of the trailer (which, 30 in this context, is taken to include the laterally projecting supports 24) allows the feet to remain stationary relative to the ground while the first and second side portions 30, 40 are moved laterally relative to the spine. However, in an alternative embodiment, 35 lifting mechanisms could be provided on the first and second side portions 30, 40. In such an arrangement the ground engaging parts of the lifting mechanism would be N:\Brisbane\Cases\Patent\790079999\P7983.AU\Specs\P79833.AU Specification 2009-1-13.doc 30101/09 - 17 required to move in the lateral direction as the first and second side portions 30, 40 are moved laterally relative to the spine, and this could be facilitated by providing castors or wheels (arranged to facilitate such lateral 5 movement) rather than feet. Alternatively, or additionally, one or more support legs which do not form part of lifting mechanisms may be provided attached to at least one of the first and second side portions. Such support legs may enhance stability of the trailer when it 10 is lifted. The support legs may be provided with mechanisms to allow them to lock, or be locked, in an extended position so that they can support the trailer body. The support legs may be provided with mechanisms to allow them to extend downwards but restrict inadvertent 15 retraction under load. One example of such a mechanism is a ratchet-type mechanism, for example including a rack or wheel with asymmetric teeth and one or more pawls which allow movement of the rack or wheel in a first (leg extension) direction, but which restrict movement in a 20 second (leg-retraction) direction. The or each support leg may be extended (eg, under power, under gravity, or manually) as or when the trailer body is lifted, and be retained in its extended position to provide support to a lifted trailer. The or each support leg may comprise a 25 ground engaging portion adapted to facilitate lateral movement relative to the ground. The ground engaging portion may comprise one or more wheels, castors and/or rollers (arranged to facilitate such lateral movement). It will further be appreciated that in the 30 illustrated embodiment a lifting mechanism is provided towards the rear of the trailer, or at least at the rear half of the trailer. This is particularly appropriate for semi trailers (which do not have front axles, and which in use may be supported at the front by a dolly, by a 35 truck/prime mover or by legs lowered prior to disconnection of the trailer from a dolly or truck). In some embodiments one or more further lifting mechanisms N:\Brisban\Cases\Patent\790O79999\P79833.AU\Specis\P79833.AU Specification 2009-1-13.doc 30/01/09 - 18 could be provided further forward on the trailer, for example so that all the wheels of a full trailer can be relieved of the weight of the trailer and/or lifted off the ground. s In preferred embodiments the one or more lifting mechanisms can not only lift the weight of the trailer, but also can lift it when it is loaded. For a low loader for use in transporting heavy machinery this may typically involve an aggregate trailer mass of approximately 45 10 tonnes (being the combined tare weight of the trailer and the payload). This facilitates lifting of the trailer body even when loaded, allowing the lifting mechanisms be used to raise wheels of a loaded trailer off the ground to enable tyres and wheels to be changed as necessary. 15 Although described with reference to suspension widening trailers, it will be appreciated that the principles and lifting mechanism operation disclosed herein are applicable to other types of suspension widening transport. For example, if desired the 20 principles and lifting mechanism operation disclosed herein could be applied to any type of suspension widening vehicle. Modifications and improvements may be incorporated without departing from the scope of the 25 invention. It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia 30 or any other country. In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as 35 "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further N:\Brisbano\Cases\Patent\79000-79 9P7983.AUSpecis\P79833.AU Specification 2009-1-13.doc 30101/09 - 19 features in various emibodiments of the invention. N*BrnsbaneCaseaPatei790DO-79999iP7S833 ALASpecaXP79833 AU Specification 2009-1-13.doc 30/01/09

Claims (20)

1. A trailer comprising a trailer body, at least one wheel provided on a first lateral side thereof and at least one wheel provided on a second lateral side thereof, 5 wherein the distance between the wheels, in a transverse direction of the trailer can be varied between a first smaller distance and a second greater distance, and wherein the trailer further comprises a lifting mechanism operable to lift at least part of the trailer body in 10 order to reduce the weight of the trailer borne by the wheels.

2. A trailer as claimed in claim 1, comprising more than one lifting mechanism.

3. A trailer as claimed in either preceding claim is wherein the one or more lifting mechanisms are operable to lift at least part of the trailer body so that substantially none of the weight of the trailer is borne by the wheels.

4. A trailer as claimed in any preceding claim 20 wherein the one or more lifting mechanisms are operable to lift at least a rear part of the trailer body in order to reduce the weight of the trailer borne by wheels located at the rearmost half of the trailer.

5. A trailer as claimed in any preceding claim 25 wherein the one or more lifting mechanisms are operable to lift at least part of the trailer body so that at least some of the wheels of the trailer are lifted clear of the ground.

6. A trailer as claimed in any preceding claim 30 wherein the trailer body comprises a central spine, a first lateral side portion to which the at least one wheel provided on the first lateral side of the trailer body is mounted, and a second lateral side portion to which the at least one wheel provided on the second lateral side of the 35 trailer body is mounted.

7. A trailer as claimed in claim 6 wherein at least one lifting mechanism is attached to the central spine. N:\BrisbaneCasestPatent\79000-799 \P79833.AU\Specis\P79833.AU Specification 2009-1-13.doc 30/01109 - 21

8. A trailer as claimed in either of claims 6 or 7 further comprising one or more support legs, which do not form part of lifting mechanisms, attached to at least one of the first and second lateral side portions. 5

9. A trailer as claimed in either of claims 6 or 7 wherein the central spine defines a space therein and at least part of a lifting mechanism is accommodated within the space.

10. A trailer as claimed in any preceding claim 10 wherein at least one lifting mechanism comprises at least one extendable member extendable downwardly from the trailer body in order to engage the ground.

11. A trailer as claimed in claim 10 wherein the lifting mechanism comprises a guide portion for guiding 15 the at least one extendable member, the guide portion comprising a tubular guide member which cooperates with the extendable member in a telescoping arrangement.

12. A trailer as claimed in either of claims 10 or 11 wherein the lifting mechanism comprises a driving 20 mechanism to drive the at least one extendable member, the driving mechanism comprising at least one of: an electric motor; a hydraulic piston; a pneumatic piston; an internal combustion engine.

13. A trailer as claimed in any preceding claim 25 wherein the trailer is elongate and has a front and a rear, wherein the trailer comprises a plurality of sets of wheels, each set comprising two or more substantially coaxial wheels, and the sets being spaced apart along the trailer in a direction of elongation of the trailer, and 30 wherein at least part of a lifting mechanism is located more rearwardly, on the trailer, than at least one of the sets of wheels.

14. A trailer as claimed in claim 14 wherein at least one extendable member of at least one lifting mechanism, 35 extendable downwardly from the trailer body in order to engage the ground, is located more rearwardly, on the trailer, than at least one of the sets of wheels. N:\Brsbane\Cases\Patent\790D-79999\P79833.AU\Specis\P79833AU Specification 2009-1-13 doc 30/01/09 - 22

15. A method of operating a trailer which comprises a trailer body, at least one wheel provided on a first 5 lateral side thereof and at least one wheel provided on a second lateral side thereof, wherein the distance between the wheels, in a transverse direction of the trailer can be varied between a first smaller distance and a second greater distance, the method comprising the steps of: 10 operating a lifting mechanism to lift at least part of the trailer body to reduce the weight of the trailer borne by at least one wheel provided on a first lateral side thereof and at least one wheel provided on a second lateral side thereof; 15 adjusting the distance, in a transverse direction of the trailer, between at least one wheel provided on the first lateral side of the trailer body and at least one wheel provided on a second lateral side of the trailer body; and 20 operating the lifting mechanism to lower said at least part of the trailer body.

16. A method as claimed in claim 15 wherein the trailer body comprises a central spine, a first lateral side portion to which the at least one wheel provided on 25 the first lateral side of the trailer body is mounted, and a second lateral side portion to which the at least one wheel provided on the second lateral side of the trailer body is mounted, and the step of adjusting the distance, in a transverse direction of the trailer, between at least 30 one wheel provided on the first lateral side of the trailer body and at least one wheel provided on a second lateral side of the trailer body comprises adjusting the distance, in a transverse direction of the trailer, between the first lateral side portion and the second 35 lateral side portion.

17 A method as claimed in either of claims 15 or 16 wherein the step of operating the lifting mechanism to N:\Brisbane\Cases\Patent\790O79999\P79833.AU\Specis\79833.AU Specification 2009-1-13.doc 30/01/09 - 23 lift at least part of the trailer body to reduce the weight of the trailer borne by at least one wheel provided on a first lateral side thereof and at least one wheel provided on a second lateral side thereof comprises s operating the lifting mechanism to lift at least one wheel provided on a first lateral side of the trailer body and at least one wheel provided on a second lateral side of the trailer body substantially clear of a surface on which the trailer stands. 10

18. A method of modifying a trailer which comprises a trailer body, at least one wheel provided on a first lateral side thereof and at least one wheel provided on a second lateral side thereof, wherein the distance between the wheels, in a transverse direction of the trailer can 15 be varied between a first smaller distance and a second greater distance, the method comprising fitting to the trailer body a lifting mechanism operable to lift at least part of the trailer body in order to reduce the weight of the trailer borne by the wheels. 20

19. A trailer substantially as hereinbefore described with reference to and as illustrated by the accompanying drawings.

20. A method of operating a trailer which comprises a trailer body, at least one wheel provided on a first 25 lateral side thereof and at least one wheel provided on a second lateral side thereof, wherein the distance between the wheels, in a transverse direction of the trailer can be varied between a first smaller distance and a second greater distance, substantially as hereinbefore described 30 with reference to the accompanying drawings and as illustrated by Figures 1 to 8. N:\Brisbane\Cases\Patent\79000-79999\P79833 AU\lSpecis\P79833.AU Specification 2009-1-13 doc 30/01/09