WO2019148237A1

WO2019148237A1 - Height adjustable trailer

Info

Publication number: WO2019148237A1
Application number: PCT/AU2019/050064
Authority: WO
Inventors: Nicholas Mebberson; Beau KUCHEL
Original assignee: Bespoke Engineering Pty Ltd
Priority date: 2018-01-30
Filing date: 2019-01-29
Publication date: 2019-08-08

Abstract

There is proposed a height adjustable trailer comprising a chassis supported on at least two wheels, a drawbar having a tongue for connection to a towing vehicle, the drawbar being pivotable relative to the chassis, a body generally rigidly mounted to said chassis, first adjustment member/s attached to said axle or respective independent suspension for raising and lowering the chassis, second adjustment member/s for adjusting the angle of said drawbar relative to the chassis, wherein said drawbar or part thereof, is detachable from said chassis. The trailer can be lowered so that it is supportable on a ground surface and the hitch may be removed or the wheels moved relative to the chassis to improve the functionality of the trailer.

Description

HEIGHT ADJUSTABLE TRAILER

FIELD OF THE INVENTION

The present disclosure relates generally to lowerable trailers and in one aspect relates to a height adjustable trailer with movable wheel bogeys and a detachable hitch.

BACKGROUND OF THE INVENTION

Trailers and transportable accommodation units, such as caravans, typically comprise a chassis, supported on wheels connected to a respective axle or independent suspension, a drawbar connectable to a towing vehicle, and a body fixedly attached to the chassis. The body may simply be a flatbed tray of tracks, such as in the case of a car transport trailer, or may include an enclosed or semi- enclosed body, such as in the case of a caravan, horse trailer or enclosed trailer.

At times, especially where storage space is limited, it is desirable to have a detachable drawbar or part thereof. One example of a pivotal and/or removable trailer hitch is disclosed in U.S. Patent Application No. 2003/0127827 to HULSEY, wherein the trailer hitch is releasably attached to a trailer frame. An aperture in the trailer hitch is positioned to coaxial align an aperture in the frame when the trailer hitch is in a towing position, and a removable lock pin is adapted to pass

therethrough to hold the trailer hitch in a fixed position relative to the frame.

However, it is recommended that the tongue weight (TW), being the downward force that the tongue of the trailer applies to the hitch of the tow vehicle, should be between 9% and 15% of the gross trailer weight (GTW). Accordingly, it would be problematic for the device disclosed in HULSEY to be used when the trailer is still coupled to the towing vehicle.

Typically, the chassis or the trailer is held spaced apart from the ground by the wheels. Whilst, some limited movement is possible, due to the configuration of the suspension, the chassis is typically not lowerable onto the ground surface. There are times where a lowered trailer is desirable, such as to assist in the loading or unloading of a trailer’s load. To load a rigid car trailer, long and heavy ramps need to be fitted to the trailer’s end. The vehicle is then typically driven up the ramps, however because the driver cannot see the narrow ramps they are usually guided by a second person. There is the risk that the vehicle may fall off the ramps, or may not be able to drive up the ramps due to poor traction, such as on wet days. A lowerable trailer is disclosed in U.S. Patent Application No. 2011/0299963 AUBREY, that uses a pneumatic suspension system to raise and lower a trailer bed. The pneumatic cushions can be vented to allow the bed of the trailer to lay flat on the ground. Another pneumatic cushion changes the angle of the bed relative to the tongue to ensure that both the front and the back of the chassis come into contact with the ground surface. Another similar height adjustable trailer is disclosed in Australian Innovation Patent 2009100804 to NGUYEN. The prior art however does not disclose a height adjustable trailer with detachable hitch or part thereof.

Another problem with currently available height adjustment vehicle carriers is that the wheels of the trailer impede access of the vehicle positioned thereon, when the trailer is in the lowered position.

It is therefore an object of the illustrated embodiments to provide for a height adjustable trailer that can be supported on a ground surface. Other objects of the illustrated embodiments are to provide movable wheel assemblies, provide a built-in hoist and/or a pivotable hitch. It is still other objects of the illustrated embodiments to overcome at least some of the aforementioned problems, or at least provide the public with a useful alternative. The foregoing objects should not necessarily be considered as cumulative and various aspects of the invention may fulfil one or more of the above objects.

The phrase“trailer” used throughout the specification should be understood to include any type of towable vehicle including, but not limited to, goods trailers, flatbed trailers, tradesman trailers, storage trailers, car carriers, boat trailers, horse floats, on-road camper trailers, on-road caravans, off-road camper trailers, off-road caravans, tent trailers, haulage trailers, mobile accommodation units, transportable buildings or any other type of towable trailer having a drawbar and being configured to be towed by a towing vehicle. The terms“bogey” or“wheel bogey” used throughout the specification should be understood as a carriage or subassembly that is movably connected to the trailer body. It should be appreciated that any discussion of the prior art throughout the specification is included solely for the purpose of providing a context for the present invention and should in no way be considered as an admission that such prior art was widely known or formed part of the common general knowledge in the field as it existed before the priority date of the application.

SUMMARY OF THE INVENTION

The invention could be broadly understood to comprise a lowerable trailer including, a body supported on at least two wheels, a drawbar detachable connected to the body for coupling to a towing vehicle, a first adjustment member or members for adjusting the body relative to the wheels whereby the body can be supported on or adjacent a ground surface, a second adjustment member or members for adjusting the drawbar or part thereof relative to the body and the towing vehicle, wherein the second adjustment member of members can be operated to permit the operation of the first adjustment member or members such that the body is supportable on or adjacent the ground surface.

Preferably the first and second adjustment members may be independently operated.

In one aspect of the invention, but not necessarily the broadest or only aspect there is proposed a height adjustable trailer, including,

a chassis supported on at least two wheels connected to an axle or respective independent suspension units,

a drawbar having a tongue for connection to a towing vehicle, the drawbar being pivotable relative to the chassis,

a body generally rigidly mounted to the chassis,

a first adjustment member or members attached to the axle or respective

independent suspension units for raising and lowering the chassis,

a second adjustment member or members for adjusting the angle of the drawbar or part thereof relative to the chassis,

wherein the drawbar or part thereof, is detachable from the chassis.

Preferably, the first adjustment member or members are part of the suspension system of the trailer.

In one form, the first adjustment member or members is/are pneumatic spring/s or bladder/s or air bag/s, which are able to be inflated or deflated to raise or lower the chassis of the trailer. The first adjustment member/s may also be hydraulic and/or electric or a mechanical device, such as but not limited to a lever.

The second adjustment member or members may form part of the

suspension system of the trailer or be independent thereof. The second adjustment member or members may be pneumatic or hydraulic or electric, or may comprise a manually activated ratchet system.

The first and/or second adjustment members may be electrically control. An electrical pump operated by an independent battery or a battery of the towing vehicle, may be used to operate the air bladders or hydraulic device. The pneumatic or hydraulic first and/or second adjustment members in one form are able to provide a dampening when the trailer is being towed and a means to lower or raise the trailer when stationary.

The trailer may include safety mechanisms to prevent the trailer being lowered whist it is being towed. These may comprise automatic locking pins that are actuated by an electronic control means from the towing vehicle or manual locking members that are operatable by a user.

In one form the second adjustment member or members include a manually operatable actuation control, such as a locking pin, that can be removed by a user prior to lowering the trailer. Alternatively, the actuation control of the second adjustment member may be electrically controlled.

The drawbar or part thereof is detachable from a mount that is fixedly connected to, or forms part of the chassis. In this way when the trailer is being stored or the chassis or body is supported on a ground surface, the drawbar can be removed.

The body may include a generally flat bed or tracks for supporting a car thereon. The generally flat bed or tracks may include frame members at both ends thereof for attachment of ramps thereto. This may be beneficial if there is limited space where the trailer is being unloaded. For instance, where the trailer is a car carrier, the trailer can be positioned within a shed and the chassis lowered so that it is resting on a ground surface. The drawbar can then be removed, which allows the car that is positioned on the trailer to be driven off the front of the trailer. The reader will also appreciate that this means that the trailer can be stored below a car in a shed while still allowing a car to be driven on or off with relative ease.

In one form, the mount may be configured to receive other structural or storage members. For instance, the drawbar can be removed and an engine hoist can be installed. This means that the trailer could be driven to a race meet and provide a lowerable trailer to assist with the unloading and loading of a race vehicle, while also providing a system for undertaking engine repairs or tuning onsite.

In another form, a part of the flat bed or tracks may be lifted when the chassis or body is supported on the ground to thereby act as a vehicle hoist to raise the vehicle/car off the body of the trailer so that work on the undercarriage can be undertaken. The drawbar may include a vertical adjustment member to accommodate tow hitches on the towing vehicle of different heights.

Preferably, the second adjustment member or members can be operated whilst the trailer is still coupled to the towing vehicle. In this way, the trailer can be positioned on the ground before being detached from the towing vehicle or it may remain coupled to the towing vehicle in the lowered position. This has several advantages and minimises the risks associated with movement of an uncoupled trailer.

In one form, auxiliary wheels may be connected to the detached drawbar, such that the drawbar can be towed to another location independent of the chassis.

The trailer may be a transportable accommodation unit, such as but not limited to a caravan, portable home or office. Accordingly, the transportable accommodation unit can be towed to a location and lowered onto the ground or a support structure and the drawbar detached. This means that a single drawbar can be used to sequentially move multiple transportable accommodation units.

Furthermore, from a security point of view the removal of the drawbar inhibits unauthorised removal of the accommodation unit.

The body may provide a living space including at least one sleeping structure and may include an expansion portion or portion, such as but not limited to, an ensuite, kitchen space and/or sleeping compartments.

In one form the wheels of the trailer, such as the transportable

accommodation unit, are removable. This means that the trailer can be located onsite and lowered onto the ground, the drawbar and wheels can then be removed and placed in storage to prevent damage due to weather or tampering.

The lowering of the trailer has particular benefits for loading and unloading cargo such as a car or a horse being transported by horse float. However, the reader will also appreciate that the lowering of the trailer onto the ground has benefits for transportable accommodation unit, such as caravans, since the user is not required to climb steps that can be problematic for many older users of caravans.

Furthermore, since the chassis is supported on the ground surface there is no longer any need to wind down stabilising legs at each corner of the caravan.

Supporting the trailer along the length of the chassis provides greater stability than individual legs that often require pads to be place underneath to prevent them sinking into the ground, which can become displaced or can be ineffective on soft ground. A hoist may be attached or attachable to the trailer intermediate of parallel tracks. The hoist being movable between a folded and lowered position and a raised position, when the chassis is resting on the ground.

The hoist may include a main body, an upper part, scissor arms outer, scissor arms inner, hydraulic rollers, scissor rollers, hydraulic mount, hydraulic cylinder, hydraulic cylinder shaft, four pivotable hoist arms, hoist arm fixing means and arm bumper. The hoist arm fixing means may include a mount clevis, tie rod and arm bush, and the hoist arms may be configured to pivot around a generally vertical axis.

The upper part of the hoist may include a slot, for receiving therethrough top parts of the hydraulic cylinder, hydraulic cylinder shaft and hydraulic mount, when the hoist is in the lowered position.

The hoist may further include locking means or safety devices that fix the hoist in the raised position to inhibit unintended lowering thereof.

Each wheel of the trailer is preferably coupled to a respective movable bogey, and can be adjusted along the longitudinal length of the chassis using

hydraulic/pneumatic actuation, a rack and pinion system, or a ball screw

arrangement. The reader will however appreciate that each bogey may have more than one wheel attached thereto.

In one form each bogey includes a swing arm, shock absorber inners, shock absorber outers, radial bearing inner, hydraulic cylinder, airbag, spherical inner, hydraulic cylinder shaft, swing arm air bag mount, swing arm shaft inner, hydraulic mount, bogey sliders/spur gears attachable to a respective clevis or mount, shaft bush inner, airbag upper mount plate, toe and camber adjustment block, hydraulic bogey mount and bogey frame.

Preferably, lowering the trailer is undertaken in a two-stage process. Firstly, an airbag is deflated that causes the bogey and chassis attached thereto, to be lowered partially. Then the hydraulic cylinder is actuated to lower the chassis onto the ground surface such that it supported thereon. At least a part of the chassis preferably extends below the bogey, such that the bogey is able to slide or move along the underside of the chassis, even when the chassis is resting on the ground.

When the chassis is being lifted off the ground the hydraulic cylinder raises the chassis off the ground slightly and then the airbag suspension takes over and lifts the chassis to desired ride height. The bogey frame may further include a swing arm shaft retainer, airbag plate clevis outer, airbag plate clevis inner, aperture, radial bearing outer and shock absorber frame clevis.

The bogey may include a main shaft with pinion gear, rack, hydraulic cylinder, damper shaft, and damper coil spring. The bogey may further include a reduction gear, that engages the pinion gear on said main shaft.

The drawbar may include a main hitch arm, winch, draw bar extension, hitch attachment plate having a plurality of apertures for securing the hitch at different heights, by way of bolts and nuts. The drawbar may further include a drawbar locking pins, pivot pins, hydraulic cylinder and hydraulic cylinder shaft. The hydraulic cylinder may be connected to a mount on a vertical support member, and held by way of locating pin. The hydraulic cylinder shaft may be connected to a mount on the trailer and held in place by way of corresponding locating pin.

The main hitch arm may be connected to mounts on the trailer and held, either pivotably or fixedly, by drawbar locking pins and pivot pins.

In another aspect of the invention there is proposed a method of lowering or raising a trailer, including the steps of:

providing a trailer having a chassis supported on at least two wheels connected to an axle or respective independent suspension units, a drawbar having a tongue for connection to a towing vehicle, the drawbar being pivotable relative to the chassis, a body generally rigidly mounted to the chassis, a first adjustment member or members attached to the axle or respective independent suspension for raising and lowering the chassis, and a second adjustment member or members attached between the drawbar and chassis;

coupling the trailer to a towing vehicle;

operating the second adjustment member or members to adjust the angle of the drawbar relative to the chassis;

operating the first adjustment member or members to raise or lower the chassis; wherein the chassis is lowered such that it is supported on, or adjacent a ground surface, or the chassis is raised to lift the chassis off the ground surface such that it is supported on the wheels.

The above method including the step of detaching the drawbar or part thereof from the chassis when the chassis is supported on or adjacent the ground surface.

The above method including the step of removing or moving a wheel or wheels from, or relative to, the chassis. The above method of lowering or raising the trailer further including the step of attaching an engine hoist to a mount from which the drawbar has been removed.

The above method of lowering or raising the trailer including the step of operating a vehicle hoist to lift a vehicle supported on the trailer, when the chassis is supported on or adjacent the ground surface.

The above method of lowering or raising the trailer including the step of attaching a wheel or wheels to the drawbar, such that the drawbar can be towed by the towing vehicle independent of the chassis.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an implementation of the invention and, together with the description and claims, serve to explain the advantages and principles of the invention. In the drawings,

Figure 1 is a perspective of a first embodiment of the trailer of the present invention;

Figure 2 is a top view of the trailer of Figure 1 ;

Figure 3 is a perspective view of the trailer of Figure 1 with drawbar detached and front ramps attached;

Figure 4 is a top view of the trailer of Figure 3, with ramps attached;

Figure 5 is a side view of the trailer of Figure 1 in a raised position;

Figure 6 is a side view of the trailer of Figure 5 in a lowered position;

Figure 7 is a side view of the trailer of Figure 6 with drawbar removed and front ramps attached;

Figure 8 is a front view of the trailer of Figure 5;

Figure 9 is a front view of the trailer of Figure 6;

Figure 10 is a front view of the trailer of Figure 9 with drawbar lowered onto the ground;

Figure 1 1 is a perspective view of the drawbar of Figure 1 detached from the chassis;

Figure 12 is a front view of the drawbar of Figure 11 ;

Figure 13 is a side view of the drawbar of Figure 11 ;

Figure 14 is a top view of the drawbar of Figure 11 ;

Figure 15 is a perspective view of the drawbar of Figure 1 in a lower position and detached from the chassis and towing vehicle;

Figure 16 is a front view of the drawbar of Figure 15; Figure 17 is a side view of the drawbar of Figure 15;

Figure 18 is a top view of the drawbar of Figure 15;

Figure 19 is a perspective view of the drawbar with auxiliary wheels attached; Figure 20 is a front view of the drawbar of Figure 19;

Figure 21 is a side view of the drawbar of Figure 19 with safety flag attached; Figure 22 is a side view of the trailer of Figure 1 with rear ramps and engine hoist attached;

Figure 23 is a perspective view of the trailer of Figure 22;

Figure 24 is a perspective view of the trailer of Figure 1 in a lowered position, illustrating one embodiment of a vehicle hoist;

Figure 25 is a side view of another embodiment of the trailer in the form of a caravan having the drawbar removed;

Figure 26 is a side view of still another embodiment of the trailer in the form of a tear drop trailer, illustrating an expandable living area;

Figure 27 is a side view of yet another embodiment of the trailer in the form of a horse float, with ramp lowered;

Figure 28 is a side view of the trailer of the present invention in a lowered

position attached to a towing vehicle;

Figure 29 is a perspective view of the trailer of Figure 1 illustrating the wheel assemblies and drawbar detached from the chassis;

Figure 30 is a side view of the trailer attached to a towing vehicle, with a

car/vehicle being loaded onto the trailer;

Figure 31 is a side view of the trailer of Figure 30 illustrating the shallow

approach angle required to load the trailer of the present invention;

Figure 32 is a side view of the trailer of the present invention indicating the steep approach angle required for conventional trailer which cannot be lowered;

Figure 33 is a side view of the trailer of Figure 30 illustrating two wheels raised and two wheels lowered;

Figure 34 is a rear view of the trailer and towing vehicle of Figure 30 illustrating the trailer in a lowered position;

Figure 35 is a rear view of the trailer and towing vehicle of Figure 34 illustrating a car/vehicle loaded onto the lowered trailer;

Figure 36 is a perspective of a yet another embodiment of the trailer attached to a towing vehicle;

Figure 37 is a side of the trailer and vehicle of Figure 36;

Figure 38 is an exploded view of the trailer of Figure 36; Figure 39 is an exploded view of the movable bogey of Figure 38;

Figure 40a is a side view of the movable bogey of Figure 38 illustrating the

suspension unit and wheel in a first position;

Figure 40b is a side view of the suspension unit and wheel of Figure 40a in a second position;

Figure 40c is a side view of the suspension unit of Figure 40a in a third position; Figure 41a is a perspective view of Figure 40a;

Figure 41 b is a perspective view of Figure 40b;

Figure 41 c is a perspective view of Figure 40c;

Figure 42 is an exploded view of the bogey frame of Figure 39;

Figure 43 is an exploded view of the hitch of Figure 38;

Figure 44 is a perspective view of the trailer of Figure 36 illustrating the movable bogeys in a second position relative to the length of the trailer;

Figure 45 is a side view of the trailer of Figure 44, illustrating access to the

vehicle driver’s door;

Figure 46a is a perspective view of the hoist of Figure 38;

Figure 46b is a cross-sectional view through A-A of the hoist of Figure 46a;

Figure 47a is a perspective view of the hoist of Figure 38 with arms extended; Figure 47b is a cross-sectional view through B-B of the hoist of Figure 47a;

Figure 48a is a perspective view of the hoist of Figure 38 with arms extended, in a fully raised position;

Figure 48b is a cross-sectional view through C-C of the hoist of Figure 48a;

Figure 49 is a perspective view of the trailer of Figure 36, illustrating the hoist in a partially raised position;

Figure 50 is a perspective view of the trailer of Figure 36, illustrating the hitch detached and the ramp attached at a front of the trailer;

Figure 51 is an exploded view of another embodiment of the movable bogey; Figure 52 is a side view of the movable bogey of Figure 51 in a lowered position; Figure 53 is a perspective view of the movable bogey of Figure 51 in a lowered position;

Figure 54 is a side view of the movable bogey of Figure 51 in a raised position; Figure 55 is a perspective view of the movable bogey of Figure 51 in a raised position;

Figure 56 is an exploded view of yet another embodiment of the movable bogey; Figure 57 is a perspective view of the movable bogey of Figure 56 in a lowered position; and

Figure 58 is a cross-sectional view through D-D of the bogey of Figure 57. DETAILED DESCRIPTION OF THE ILLUSTRATED AND EXEMPLIFIED

EMBODIMENTS

Similar reference characters indicate corresponding parts throughout the drawings. Dimensions of certain parts shown in the drawings may have been modified and/or exaggerated for the purposes of clarity or illustration.

Referring to the drawings for a more detailed description, there is illustrated a height adjustable trailer 10, demonstrating by way of examples, arrangements in which the principles of the present invention may be employed.

Figure 1 illustrates one embodiment of the height adjustable trailer 10 in the form of a car carrier 12, including a chassis 14 supported on wheels 16a, 16b, 16c, 16d, connected to respective independent suspension units 18a, 18b, 18c, 18d. A drawbar 20 having a tongue or hitch 22 for connection to a towing vehicle 26, as illustrated in Figure 30. A jockey wheel 21 may be connected to the drawbar 20 as is known in the art. The tongue or hitch 22 includes a vertical adjustment member 23 to accommodate tow hitches on the towing vehicle of different heights.

As further illustrated in Figure 1 , the trailer 10 includes a body 28 that is rigidly mounted to the chassis 14. The body 28 in the present embodiment comprises panels 30, which form parallel tracks 32, 34, and intermediate panels 36 38, with a void 40 in the middle of the body 28, as is known in the art.

Respective first adjustment members 42 are attached to the independent suspension units 18a, 18b, 18c, 18d for raising and lowering the chassis 14.

A hinge assembly 44, which includes a second adjustment member 46 is attached to or forms part of the drawbar 20. The reader should appreciate that although one embodiment of the hinge assembly 44 is illustrated other systems fall within the scope of the invention, such that the angle of the drawbar 20 can be adjusted relative to the chassis 14 while the trailer 10 is still connected to the towing vehicle 28, as shown in Figures 31 and 32.

Figures 1 and 2 illustrate the fenders 48 that are connected to respective independent suspension units 18a, 18b, 18c, 18d or wheel assemblies. The fenders 48 are caused to rotate around the axis of the respective wheel 16, as illustrated in Figure 3. The trailer 10 also includes rear taillight units 50, with relevant wiring (not shown).

The skilled addressee will appreciate that the wheels 16 may be connected to respective axles and the chassis or body may include a lateral cavity (not shown) into which the axle is retracted when the trailer is lowered, such that the main part of the chassis is able to rest on the ground surface.

The adjustment members 42 and 46 comprise air bags that are inflated and deflated to lift/lower the trailer 10 or change the angle of the drawbar 20. The adjustment members 42 and 46 may be part of the suspension system of the trailer 10. The air bags of adjustment members 42 and 46 of the present embodiment, are caused to imping upon abutment members 52 or 54 respectively to control operation of the height adjustable trailer 10.

Frame members 56 are located at either ends of parallel tracks 32, 34 for attachment of ramps 58, as shown in Figures 3 and 23.

The drawbar 20, or part thereof, is detachable from the chassis 14. The drawbar 20 includes a coupling 60 that is connectable to a mount 62 on the chassis 14. The detachment of the drawbar 20 means that the ramps 58 can be attached to the front of the car carrier 12, as illustrated in Figure 3. This means that a vehicle on the car carrier 12 can be unloaded off the front of the trailer 10 once the drawbar has been removed, which is helpful if the trailer 10 is parked in a shed or space behind the trailer 10 is limited due to the location of an obstacle 64, as illustrated in Figure 4.

Figures 1 1 to 18 illustrate one embodiment of the drawbar 20, that comprise a first portion 66 pivotably connected to a second portion 68. The first portion 66 is detachable connectable to the chassis 14 by way of coupling 60. The abutment member 52 is rigidly attached to the first portion 66 and reinforced by brackets 69. In the present embodiment, the first portion 66 comprises two spaced apart rails 70, 72. The second portion 68, which in the present embodiment comprises a length of SHS tubular steel 74, is connected at a first end 76 to a pivot, which comprises a shaft 80 that extends through coaxially aligned apertures 82, 84 in the spaced apart rails 70, 72. The second end 78 of the second portion 68 is configured to engage with or be connected to the tongue or hitch 22, and includes a mount 86. The second adjustment member 46 is mounted onto the second portion 68.

Figures 15 to 18 illustrate the second portion 68 being pivoted relative to the first member 66. This ensures that the chassis 14 of the trailer 10 can be lowered onto the ground surface while the trailer 10 is still connected to the vehicle 26. As illustrated in Figures 15 and 17, the second portion 68 includes a laterally extending passageway 88, which is configured to engage with locking member 90. The locking member 90 holds the second member 68 in a fixed position relative to the first member 66, such as when the trailer 10 is being towed. The locking member 90 can be automatically or manually disengaged when the trailer 10 is to be lowered. In this way, the second portion 68 of the drawbar 20 can be pivoted relative to the chassis 14.

As illustrated in Figures 19 to 21 , when the drawbar 20 has been detached from the trailer 10, auxiliary wheels 92 can be connected thereto, wherein the drawbar 20 can be towed away by the towing vehicle or another towing vehicle. In this way, the drawbar 20 can be coupled to different trailers or can be moved to a remote location for storage. The auxiliary wheels 92 may be 12-inch standard trailer tyres or similar. As illustrated in Figure 21 , a safety flag 94 can be mounted to the end of the first portion 68 when it is being towed independent of the chassis 14.

As illustrated in Figures 22 and 23, when the drawbar 20 is detached from mount 62 an engine hoist 96 can be connected thereto. The engine hoist 96 comprises a base 98, A-frame vertical support 100, adjustable arm 102 and adjustment member 104. The engine hoist 96 can be used to undertake repairs, modifications or tuning onsite at a race meeting.

The body 28 of the trailer 10 may also include vehicle hoist members 106 that form part of the flatbed or tracks. The vehicle hoist members 106 can be raised by lifting members 108 when the trailer 10 is resting on the ground surface, as illustrated in Figure 24.

The body 28 of the trailer 10 can also be in the form of an enclosed living area, such as a caravan 1 10, as illustrated in Figure 25. The caravan may have a door 112, windows 1 14 and an expandable portion 116. Various configuration of caravans or tent trailers are envisaged, wherein the trailer 10 can be lowered on the ground, such that the chassis 14 rests on the ground surface. This means that access to the caravan 110 only requires a small step up, rather than climbing stairs, as is the case with modern caravans. This has a number of safety benefits for older users, that regularly use caravans. Furthermore, since the caravan is resting on the ground surface the stability is improved and the configuration does away with the requirement for stabilising legs, which can at times be problematic. As further illustrated in Figure 25, the drawbar 20 can be removed for storage or security reasons.

The trailer 10 may also be a tent trailer 118, as illustrated in Figure 26, which includes a single wheel 16 on either side and a body 28, tear drop rigid walls 120, a hinged roof 122, window 124, and foldable tent portion 126, with internal frame (not shown), and an access door 128. The tear drop trailer 10 can still be coupled to the towing vehicle when the chassis 14 is supported on the ground.

In another embodiment, as illustrated in Figure 27, the trailer 10 may be a horse float 130, including walls 132, front 134, window 136 and stone guard 138. Access to the horse float 130 is by way of a pivotable ramp 140, as is known in the art. The reader will appreciate that since the chassis 14 of the horse float 130 is supported on the ground the invention provides greater stability when loading or unloading an animal. Furthermore, since the ramp is at only a slight angle the loading or unloading of the animal is also made easier, since the animal does not need to climb up into the trailer.

As illustrated in Figure 28, the trailer 10 can be lowered, such that the chassis 14 rests on the surface 142 of the ground 144, while the trailer 10 is still coupled to the towing vehicle 26. In the present embodiment, the vehicle 26 is an SUV including a body 150, wheels 152 and a tow coupling 154.

As shown in Figure 29, the wheels 16 of the trailer are removable from the chassis 14. This can be done to protect the wheels from damage, to improve space and access around the trailer 10, or for security reasons, such as to inhibit unauthorised movement of the trailer 10. In the present embodiment the

independent suspension units 18a, 18b, 18c, 18d, that includes respective wheels 16, fenders 48, first adjustment members 42 and abutment members 52, which could be collectively referred to as the wheel assemblies, are detachable from the chassis 14.

Figures 30-32 and 34-35 illustrate the difference between the approach angle of a vehicle 200 being loaded onto the trailer of the present embodiment, as indicated in Figure 31 , and the approach angle of a trailer that cannot be lowered, as indicated in Figure 32. The reader would appreciate that when driving up an inclined ramp or a trailer that has the back lowered to the ground the user loading a car/vehicle may lose sight of the ramps/back of trailer due to a higher approach angle. This increases the risk of a wheel or wheels of the vehicle being loaded, falling off the ramp which can cause damage to the car/vehicle or trailer. Furthermore, the steeper approach angle limits vehicles with low ground clearance from being loaded since the underside of the vehicle may hit the trailer or the car may become wedged.

As illustrated in Figure 33, the front wheels 16a, 16c may be locked in a raised position. This means that a tandem trailer then has only two main wheels in contact with the ground. As the reader would appreciate this may be beneficial where the unloaded trailer is being moved around, since it assist with being able to pivot the trailer on only one set of wheels.

Figures 38 to 50, illustrate another embodiment of the trailer 10, wherein a hoist 210 is attached intermediate of panels 30, the suspension units 18a, 18b, 18c, 18d are in the form of movable bogeys connected to respective hydraulic/pneumatic cylinders 212 with mounting brackets 213, and the hitch 20 is movable by way of a hydraulic/pneumatic cylinder 214.

The independent suspension units also referred to as movable bogeys 18a,

18b, 18c, 18d in the present embodiment are slidably held to an underside of the chassis 14, which is shaped such that when a part of the chassis 14 of the trailer 10 is resting on the ground, the bogeys 18a, 18b, 18c, 18d are still able be moved longitudinally along the underside of the trailer 10.

As illustrated in Figure 39, each bogey 18 includes a swing arm 216, shock absorber inners 218, shock absorber outers 220, radial bearing inner 222, hydraulic cylinder 224, airbag 226, spherical inner 228, hydraulic cylinder shaft 230, swing arm air bag mount 232, swing arm shaft inner 234, hydraulic mount 236, bogey sliders 238 attachable to a respective clevis or mount 240, shaft bush inner 242, airbag upper mount plate 244, toe and camber adjustment block 246, hydraulic bogey mount 248 and bogey frame 250.

The skilled addressee will appreciate that although it is envisaged that the bogeys 18 will be moved using sliders and hydraulic/pneumatic cylinders, there may be other ways of moving the bogeys that fall within the scope of the present invention. For instance, movement of the wheels/bogeys may be via either hydraulic/pneumatic actuation, rack and pinion system, or a ball screw arrangement.

Figures 40a and 41a illustrate the bogey 18 in a raised position for towing wherein the airbag 226 is fully expanded. The reader will also appreciate that the airbag 226 is used in conjunction with the shock absorber 220 to provide dampening and shock absorbing for movement of the wheel 16 when being towed.

Lowering the trailer 10 is undertaken in a two-stage process. Firstly, the airbag 226 is deflated that causes the bogey 18 attached to the chassis 14 to be moved into a partially lowered position, as illustrated in Figures 40b and 41 b. Then the hydraulic cylinder 224 is actuated to lower the chassis 14 onto the ground surface such that it supported thereon, as illustrated in Figures 40c and 41 c. When the chassis 14 is being lifted off the ground the hydraulic cylinder 224 raises the chassis 14 off the ground slightly, as shown in Figures 40b and 41 b. At this stage the airbag 226 is inflated or partially inflated which lifts the chassis 14 to the desired ride height.

The skilled addressee with appreciate that having a two-stage system provides advantages, wherein if the hydraulic system or pneumatic air bag fail, the chassis 14 will not drop onto the ground. It will be visible that a failure of some kind has happened from the user’s perspective in the tow vehicle 26, however the trailer 10 will not pose a danger to the user or surrounding people/property. It will enable the user time to get the vehicle and attached trailer to a safe location to deal with the failure.

As illustrated in Figure 42, the bogey frame 250 further includes a swing arm shaft retainer 252, airbag plate clevis outer 254, airbag plate clevis inner 256, aperture 258, radial bearing outer 260 and shock absorber frame clevis 262. In the present embodiment, the sliders 238 have been replace with spur gears 264 that are configured to engage with a rack (not shown) connected to an underside of the chassis 14 to facilitate movement of the bogey 18 therealong.

Figure 42 illustrates the drawbar 20 and hitch 22 assembly, that includes a main hitch arm 266, winch 268, draw bar extension 270, hitch attachment plate 272 having a plurality of apertures 274 for securing the hitch 22 at different heights by way of bolts 276 and nuts 278. The assembly further includes a drawbar locking pins 280, pivot pins 282, hydraulic cylinder 284 and hydraulic cylinder shaft 286. The hydraulic cylinder 284 is connected to mount 288 on vertical support member 290, and held by way of locating pin 292. The hydraulic cylinder shaft 286 is connected to mount 294 on the trailer 10, illustrated in Figure 38, and held in place by way of locating pin 296.

The main hitch arm 266 is connected to mounts 298 on the trailer 10, illustrated in Figure 49, and held, either pivotably or fixedly by pins 280 and 282. As the reader will appreciate when the locking pins 280 are removed the drawbar 20 is able to pivot relative to the chassis 14 around pins 282.

As illustrated in Figures 44 and 45, the bogeys 18a-18c are moveable relative to the length of the chassis 14 such that the wheels 16 can be moved towards ends of the trailer 10 when the chassis 14 is resting on the ground. On the majority of height adjustable car trailers, when lowered, the wheels/mud guards swing up and make it difficult to open the car doors. This means that a user needs to lower the trailer and then raise it in order to be able to get out.

In the present embodiment, as the bogeys 18 are able to be moved longitudinal along the trailer by way of respective hydraulic/pneumatic cylinders 212, out of the way, the driver is able to open the car door 300 even when the trailer 10 is in the lowered position.

In another alternate or additional embodiment, the trailer 10 includes a hoist 210. As illustrated in Figures 44 to 50, the hoist 210 is movable between a folded and lowered position and a raised position, when the chassis 14 is resting on the ground. In this way the vehicle 200 on the trailer 10 can be lifted off the ground so repair or maintenance can be undertaken. This use of a hoist 210 that is integral with a trailer has the advantages that wherever the trailer is taken the vehicle 200 can be lifted, which is advantageous for users such as those involved in amateur race field where resources and infrastructure are limited. For instance, the user can undertake work on the vehicle’s engine/transmission/tyre, change or clean the vehicle after a race, using the hoist 210 that is attached/attachable to the chassis 14.

The hoist 210 includes a main body 302, an upper part 304, scissor arms outer 306, scissor arms inner 308, hydraulic rollers 310, scissor rollers 312, hydraulic mount 314, hydraulic cylinder 316, hydraulic cylinder shaft 318, four pivotable hoist arms 320a-d, hoist arm fixing means 322 and arm bumper 324. The hoist arm fixing means 322 in one embodiment, includes a mount clevis, tie rod and arm bush (not shown), and is configured to pivot around a generally vertical axis.

The upper part 304 of the hoist 210, includes a slot 326 that permits passage of the top parts of the hydraulic cylinder 316, hydraulic cylinder shaft 318 and hydraulic mount 314, when the hoist 210 is in the lowered position, as illustrated in Figures 46a and 46b. In this folded arrangement the hoist 210 is positioned to not impinge upon use of the trailer 10. When a user wants to lift the vehicle 200, they can lower the chassis 14 onto the ground and raise the upper part 304 of the hoist 210 slightly, as illustrated in Figure 49. This means that the hoist arms 320a-d can be pivoted outwardly over the top of panels 30 of the parallel tracks 32, 34.

The hoist 210 can then be moved into the fully extended arrangement, as illustrated in Figure 49, so that the underside of the vehicle 200 can be worked on. The hoist 201 may include locking means or safety devices that fix it in the raised position and inhibit unintended lowering thereof. As shown in Figure 50 the ramps 58 may also be connected to a front of the chassis 14, wherein the drawbar 20 can be disconnected from mounts 294 and 298, by removal of pins 280, 282 and 296. In this way the trailer can be reversed into a shed and the drawbar 20 removed for loading and unloading the vehicle, as was described with respect to Figures 4 to 7. This also means that a car can be driven onto the trailer 10 and parked thereover where space is limited. In this situation, it may be advantageous to have the wheels 16, swing arms 216 and/or bogey 18 removable attachable to the trailer 10.

Figures 51 to 58, illustrate two alternate embodiments of the movable bogey. As shown in Figure 51 the assembly includes, bearings 400, shaft spacer 402, main shaft with pinion gear 404, bump stop 406, rack 408, rack slider support 410, bogey frame 412, locking nut 414, cover/seal plate 416, mounting bolts 418, hydraulic cylinder main 420, hydraulic cylinder shaft 422, bolt 424, nut 426, damper shaft 428, coil spring 430. This configuration is used to control the movement of the bogey between the lower position, as illustrated in Figures 52, 53, and the raised position, as illustrated in Figures 54, 55.

As illustrated in Figure 56, the movable bogey may include a reduction gear 434, that in a sense acts like a gearbox. The position of the reduction gear 434 is also illustrated in Figure 58. The inclusion of the reduction gear 434, which engages the pinion gear on the main shaft 404 and allows the rack 408 to be more compact and supported while operating on the gear 434.

The inclusion of an additional pinion gear, that gets driven by the rack (rack- pinion-gear on axle) which would act as a gearbox, this reduces the force required (smaller hydraulic cylinder of longer stroke) and lengthen the (suspension) travel of the inline spring/coil over damper.

The loading on the gear/rack is high due to the high moments required to rotate and lift the trailer - which are highest when the trailer is fully lowered. This reduces the demand on the damper. As the reader will appreciate, the embodiments illustrated in Figures 51 to 58, mean that the swing arm operation with respect to the bogey is by means of a rack and pinion system.

Starting from the trailer in the‘down’ or lowered position, as illustrated in Figures 52, 53, the hydraulic cylinder (either double or single acting) is pressurised, which pushes the sliding rack (rack 408, rack slider support 410), which in turn rotates the pinion that rigidly affixed to the swing-arm axle 404, thereby lifting the trailer. With reference to Figures 51 to 58, when raised the hydraulic cylinder (hydraulic cylinder main 420, hydraulic cylinder shaft 422) is fully extended, pressurised and effectively forms a generally rigid member. The inline coil-over damper and spring arrangement (damper shaft 428, coil spring 430) is actuated by the sliding rack (rack 408, rack slider support 410) in order to provide suspension travel.

The rack 408 is pushed by the pinion gear (main shaft with pinion gear 404) that is rigidly attached to the swing-arm axle.

In order to lower the trailer, the hydraulic cylinder (hydraulic cylinder main 420, hydraulic cylinder shaft 422) is either depressurised, whilst controlling the flow through a valve (not shown) to smoothly transition, or pressurised in the opposite direction in the case of a double acting cylinder. The reader will appreciate that the present embodiment involves a single operation lifting method.

The bogeys can then be unlocked and be re-located longitudinally by way of a hydraulic cylinder (see Figures 44 and 45), allowing room for the vehicles doors to be opened. Once lowered the swing-arm 216 can be locked into position via a mechanical pin, or via the hydraulic cylinder (if double acting). This can also be utilised to lift and lock two of four wheels to improve manoeuvrability if trailer is un- laden, as discussed with respect to Figure 33.

The skilled addressee will now appreciate the advantages of the illustrated invention over the prior art. In one form the illustrated embodiments provide a trailer that can be lowered so that it is supportable on a ground surface. This has several advantages over the prior art by reducing the risks associated with uncoupled trailer, improving stability of the trailer and access thereto, as well as increasing the possible functions of the trailer. The reader will appreciate that the trailer 10 may be a car carrier, caravan, tent trailer, transportable accommodation unit, haulage trailer, horse float or any other type of trailer.

Various features of the invention have been particularly shown and described in connection with the exemplified embodiments of the invention, however it must be understood that these particular arrangements merely illustrate the invention and it is not limited thereto. Accordingly, the invention can include various modifications, which fall within the spirit and scope of the invention.

Claims

1. A height adjustable trailer comprising:

a body generally rigidly mounted to said chassis,

first adjustment member/s attached to said axle or respective independent suspension units for raising and lowering the chassis,

second adjustment member/s for adjusting the angle of said drawbar or part thereof, relative to the chassis,

wherein said drawbar or part thereof, is detachable from said chassis.

2. The height adjustable trailer in accordance with claim 1 , wherein the first

adjustment member/s and second adjustment member/s are selected from a group including, but not limited to, pneumatic or hydraulic spring/s, or pneumatic or hydraulic bladder/s, or pneumatic air bag/s, or electric lever/s or mechanical lever/s, the first and/or second adjustment members being manually or electrically controlled.

3. The height adjustable trailer in accordance with claim 2, wherein, the first

adjustment member/s and/or second adjustment member/s are part of the suspension system of the trailer.

4. The height adjustable trailer in accordance with claim 3, wherein the first

adjustment member/s provide dampening when the trailer is being towed and a means to lower or raise the trailer when said trailer is generally stationary.

5. The height adjustable trailer in accordance with claim 1 , wherein the second adjustment member/s include a locking pin or pins, configured to be removed by a user prior to lowering or adjusting said trailer.

6. The height adjustable trailer in accordance with claim 1 , wherein the drawbar or part thereof is detachable from a mount that is fixedly connected to, or forms part of said chassis, whereby the mount is configured to receive other structural or storage members, such as but not limited to, an engine hoist.

7. The height adjustable trailer in accordance with any one of the above claims, wherein the body includes a generally flat bed or tracks for supporting a car/vehicle thereon, the flat bed or tracks include frame members at both ends thereof for attachment of ramps thereto, such that said car/vehicle can be loaded or unloaded from either end of said trailer, or the body comprises a transportable accommodation unit, being a caravan, portable home or office, or the body comprises a storage or transport structure.

8. The height adjustable trailer in accordance with claim 1 , wherein a part of the body is liftable when the chassis is supported on the ground to thereby act as a vehicle hoist to raise a vehicle off the trailer so that work on the undercarriage can be undertaken, or a vehicle hoist is attachable to said chassis or body.

9. The height adjustable trailer in accordance with any one of the above claims, wherein the drawbar may include a vertical adjustment member to

accommodate tow hitches on the towing vehicle of different heights.

10. The height adjustable trailer in accordance with claim 1 , wherein the first

adjustment member/s and second adjustment member/s can be operated whilst the trailer is coupled to the towing vehicle.

1 1. The height adjustable trailer in accordance with claim 1 , wherein a wheel or wheels of the trailer is/are preferably coupled to a respective movable bogey, which can be moved longitudinally along a length of the chassis using hydraulic/pneumatic actuation, a rack and pinion system, or a ball screw arrangement.

12. The height adjustable trailer in accordance with claim 1 1 , wherein each bogey includes a swing arm, shock absorber inners, shock absorber outers, radial bearing inner, hydraulic cylinder, airbag, spherical inner, hydraulic cylinder shaft, swing arm air bag mount, swing arm shaft inner, hydraulic mount, bogey sliders/spur gears attachable to a respective clevis or mount, shaft bush inner, airbag upper mount plate, toe and camber adjustment block, hydraulic bogey mount and bogey frame.

13. The height adjustable trailer in accordance with claim 12, wherein the bogey frame further includes a swing arm shaft retainer, airbag plate clevis outer, airbag plate clevis inner, aperture, radial bearing outer and shock absorber frame clevis.

14. The height adjustable trailer in accordance with claim 1 1 , wherein the bogey includes a main shaft with pinion gear, rack, hydraulic cylinder, damper shaft, and damper coil spring.

15. The height adjustable trailer in accordance with claim 14, wherein the bogey includes a reduction gear, that engages the pinion gear on said main shaft.

16. A method of lowering or raising a trailer, including the steps of:

providing a trailer having a chassis supported on at least two wheels connected to an axle or respective independent suspension units, a drawbar having a tongue for connection to a towing vehicle, the drawbar being pivotable relative to the chassis, a body generally rigidly mounted to said chassis, first adjustment member/s attached to said axle or respective independent suspension for raising and lowering the chassis, and second adjustment member/s attached between the drawbar and chassis;

coupling said trailer to a towing vehicle;

operating the second adjustment member/s to adjust the angle of said drawbar relative to the chassis;

operating the first adjustment member or members to raise or lower the chassis;

wherein the chassis is lowered such that it is supported on, or adjacent a ground surface, or the chassis is raised to lift said chassis off the ground surface such that it is supported on said wheels.

17. The method in accordance with claim 14, further including the step of detaching the drawbar or part thereof from the chassis when said chassis is supported on or adjacent the ground surface, and/or removing a wheel or wheels from the chassis, and/or moving a wheel or wheels relative to the chassis.