AU2019208266A1 - A trailer for a road train vehicle - Google Patents

Abstract

A trailer suitable for a road train vehicle and providing improvement in the road train vehicle's stability when suddenly changing direction. The trailer comprises a fifth-wheel coupling to receive a kingpin of an adjoining trailer, wherein the fifth-wheel coupling is disposed rearwardly of a rearmost axle of the trailer. The road train vehicle may comprise a plurality of the trailers. 1/10 TT0 0n 0 - Lf4 TT TT mm 00 r-4 m C) C Cm

Description

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"A trailer for a road train vehicle" Technical Field

[0001] The present disclosure relates to a trailers, trailer connections, dollies and trailer assemblies suitable for a road train vehicle. In particular, some embodiments relate to a trailer suitable for transporting a liquid container.

Background

[0002] Road trains are heavy vehicles which typically comprise a prime mover towing multiple trailers. The mass and dimensions of a road train affects its classification under the Heavy Vehicle National Law (HVNL), which sets limits on the type of road network that the road train can access. The ability to access certain types of roads affects the routes taken by the road train, which in turn affects the time and cost associated with delivering the goods.

[0003] A road train may be reclassified under the Performance Based Standards (PBS) in order to allow it to access road networks that it would otherwise be restricted from accessing under its HVNL classification. The PBS assesses the performance of a road train under various safety focused performance criteria, and determines a PBS classification of the road train.

[0004] One of the performance criteria is the road train's ability to safely change direction, for example when changing lanes or when suddenly swerving to avoid an obstacle. The road train's ability to do so is influenced by, among other things, the number of the trailers in the road train.

[0005] It is desired to address or ameliorate one or more shortcomings associated with prior trailers used in road trains, or to at least provide a useful alternative thereto.

[0006] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each of the appended claims.

[0007] Throughout this specification the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

Summary

[0008] Some embodiments relate to a trailer suitable for a road train vehicle, the trailer comprising a trailer chassis for supporting a load to be transported; a set of axles coupled via a suspension system to the trailer chassis and positioned towards a rear end of the trailer chassis to transfer a weight of the load to the ground, wherein each axle in the set of axles is arranged perpendicular to a forward direction of travel of the trailer; and a fifth-wheel coupling coupled to the trailer chassis to receive a kingpin of an adjoining trailer, wherein thefifth-wheel coupling is disposed rearwardly of a rearmost axle of the set of axles and is coupled to the trailer chassis via a support structure that is fixedly attached to or forms part of chassis rails of the trailer chassis. A distance between a centre of the fifth-wheel coupling and the rearmost axle may measure up to 700mm.

[0009] The chassis rails may comprise a pair of elongate chassis rails extending parallel to the forward direction of travel of the trailer, and spaced apart to define therebetween an inboard section of the trailer chassis. A plurality of cross members may be disposed in the inboard section to connect the chassis rails and to provide torsional stiffness of the trailer chassis. The plurality of cross members may comprise a rearmost cross member which forms part of the support structure.

[0010] The support structure maybe disposed in the inboard section and span the inboard section to support the fifth-wheel coupling. The support structure may comprise a base plate disposed towards a bottom portion of each of the chassis rails, wherein the bottom portion is opposite to the top portion of each of the chassis rails. The rearmost cross member may be rearward of the fifth-wheel coupling connection to the base plate.

[0011] Atop portion of each of the chassis rails maybe connected to a lower portion of the load, and wherein a top plate of thefifth-wheel coupling is positioned to rest below the top portion. The top plate may be between 700mm and 1300mm above the ground. The fifth-wheel coupling may be disposed at a level that is less than or equal to a level of a top of wheels coupled to the rearmost axle. A portion of the fifth-wheel coupling may extend beyond the rear end of the trailer chassis.

[0012] Each of the chassis rails may comprise a chassis rail rear end disposed at the rear end of the trailer chassis, and at least part of the support structure may be disposed at the chassis rail rear end. The portion of the fifth-wheel coupling that extends beyond the rear end of the trailer chassis may comprise rearmost portions of the top plate of thefifth-wheel coupling.

[0013] Each chassis rail rear end may comprise a rebate portion extending from a rear extremity of the chassis rail rear end in a forward direction, wherein the rebate portion accommodates yaw movement of a towed trailer that would otherwise interfere with the chassis rails when the towed trailer is connected to thefifth-wheel coupling.

[0014] The load may include a liquid container with drainage means comprising a sump, wherein the liquid container comprises a container front end opposite to and inclined from a container rear end, and wherein the sump is located forward of the container rear end. The sump may be disposed at the container rear end and vertically in line with wheels supported by the rearmost axle.

[0015] Some embodiments relate to a trailer combination, comprising a dolly connected to the fifth-wheel coupling of the trailer, wherein the dolly comprises a drawbar. The drawbar may comprise a kingpin coupled to a skid plate, wherein the kingpin is configured to engage with the fifth-wheel coupling.

[0016] Some embodiments relate to a triple road train vehicle, comprising a prime mover towing a first trailer, a second trailer, and a third trailer; wherein the second trailer is connected to the first trailer by a first dolly, and the third trailer is connected to the second trailer by a second dolly; and wherein the first trailer and the second trailer are each the trailer.

[0017] The first dolly may comprise a first drawbar, the first drawbar comprising a first kingpin configured to engage with the fifth-wheel coupling of the first trailer. The second dolly may comprise a second drawbar, the second drawbar comprising a second kingpin configured to engage with the fifth-wheel coupling of the second trailer.

Brief Description of Drawings

[0018] Embodiments are described in further detail below, byway of example, with reference to the accompanying drawings, in which:

[0019] Figure 1 is a side view of an embodiment of a trailer suitable for a road train vehicle, in particular for transporting a liquid container;

[0020] Figure 2 is a top view of the trailer of Figure 1, with its load removed for clarity;

[0021] Figure 3 is a section view taken along the line A-A as marked on Figure 2;

[0022] Figure 4 shows a similar view to Figure 2, with the wheels and axles additionally removed to better show the trailer chassis;

[0023] Figure 5 is a perspective view of the trailer as shown in Figure 4;

[0024] Figure 6 is a perspective close-up view of the rear end of the trailer;

[0025] Figure 7 is a side view of a dolly suitable for connecting with the trailer of Figure 1;

[0026] Figure 8 is a top view of a drawbar for the dolly of Figure 7;

[0027] Figure 9 is a section view of the drawbar of Figure 8; and

[0028] Figure 10 is a side view of an embodiment of a road train vehicle comprising a plurality of the trailer of Figure 1 and the dolly of Figure 7.

Detailed Description

[0029] The present disclosure relates to a trailers, trailer connections, dollies and trailer assemblies suitable for a road train vehicle. In particular, some embodiments relate to a trailer suitable for transporting a liquid container.

[0030] A road train vehicle may have various numbers and configurations of trailers. For example, a road train vehicle may have a prime mover towing 2, 3, or 4 trailers which may each carry a load. A following/towed trailer may be connected to a preceding/leading trailer by a dolly, or be directly connected to the preceding trailer.

[0031] Figure 1 shows a trailer 100 suitable for such a road train vehicle, the trailer 100 comprising a trailer chassis 110 for supporting a load 300 to be transported, a set of axles 400 coupled via a suspension system to the trailer chassis 110, and a fifth-wheel coupling 500 coupled to the trailer chassis 110 to receive a kingpin of an adjoining trailer.

[0032] The set of axles 400 is positioned towards a rear end of the trailer chassis to transfer a weight of the load 300 to the ground, wherein each axle in the set of axles 400 is arranged perpendicular to a forward direction of travel of the trailer 100. The set of axles 400 comprises a rearmost axle 402 to which rear wheels 412 are connected, and a frontmost axle 404 to which front wheels 414 are connected. In some embodiments, the set of axles 400 comprises a middle axle group 406 arranged between the frontmost axle 404 and the rearmost axle 402.

[0033] The fifth-wheel coupling 500 is disposed rearwardly of aft of the rearmost axle 402 of the set of axles 400 and is coupled to the trailer chassis 110 via a support structure 200 that is fixedly attached to or forms part of chassis rails 120, 130 of the trailer chassis 110.

[0034] In some embodiments, the load 300 includes a container 310 for storing a liquid. The liquid container 310 comprises a front end 312 disposed opposite a rear end 314. The trailer 100 comprises a frontmost extremity 102 disposed at the front end 312 and a rearmost extremity 104 disposed at the rear end 314 of the trailer 100. The liquid container or tanker 310 may be manufactured to comply with AS2809 and may comprise container rails 316, 318 at the bottom of the container 310 to engage with the trailer chassis 110, and in particular the chassis rails 120, 130. The trailer chassis 110 may be positioned towards the rear end 314.

[0035] A skid plate 340 is connected to the container rails 316, 318 and comprises a kingpin 342. The kingpin 342 allows the trailer 100 to be connected to the fifth-wheel coupling of a prime mover, a preceding trailer or a dolly, for example, as part of a road train vehicle.

[0036] In general terms, when changing direction, a vehicle's centre of mass wants to continue in its previous direction of travel. Turning or cornering causes rolling moments, wherein the vehicle tends to rotate about its roll axis (parallel to the vehicle's forward direction of travel). Braking or accelerating causes pitching moments, wherein the vehicle tends to rotate about its pitch axis (perpendicular to the roll axis). Cornering also causes yaw, which is rotation about the yaw axis, (perpendicular to the plane defined by the roll and pitch axes). The use of a kingpin and fifth-wheel coupling connection provides a secure connection for the trailer 100. The fifth wheel coupling offers a greater surface area than a pin coupling arrangement and is able to absorb at least some of the force and torque travelling through the connected vehicles. This means that fifth-wheel couplings can provide towing stability by controlling the transfer of pitch, yaw, roll and weight loads between the vehicle elements (for example between prime mover and trailer, or between second and third trailers), which has particular advantages when a moving vehicle is changing direction.

[0037] The container 310 may contain baffles and/or compartments to reduce the sloshing or movement of the liquid through the container 310 when the trailer 100 is moved. This is particularly important when the trailer 100 is being towed, for example as part of a road train vehicle, as sloshing of the liquid can affect the stability of the vehicle during acceleration, deceleration, or directional changes, by increasing the amount of roll and pitching experienced by the vehicle.

[0038] The liquid container 310 maybe connected to a drainage system 320 comprising valves or drainage outlets for the contents of each of the compartments, and located forward of where the trailer chassis 110 supports the rear end 314. In some embodiments, the drainage system 320 comprises a sump, positioned at the lowest point of the container 310 so that the liquid can be collected and drained through the drainage outlets. Typically, the lowest point of the container is at the rear end 314. In embodiments where the container 310 comprises compartments, each compartment has a sump. The sump may be located on one side of the container rather than at the rear. The sump may be located forward of the wheels, for example, or may be vertically in line with the rear wheels 412 (forward of the rear end 314) so as to leave space at the rear end 314 for the fifth-wheel coupling 500.

[0039] A landing gear module or set of legs 330 is configured to support the trailer 100 when it is uncoupled from the vehicle, and positioned so that there is space under the front end 312 for the trailer 100 to connect via the kingpin 342 to a prime mover or another trailer such as a dolly. The kingpin 342 may be between 1.1m and 1.5m from ground level, and between 1.4m to 2.4m aft of the front extremity. In some embodiments the kingpin 342 is approximately 1.22m from ground level, and approximately 1.5m aft of the front of the container 310. The kingpin 342 may be between 2.5m to 3.5m from the legs 330, and in some embodiments is approximately 3m from the legs 330. The legs 330 may also be configured to support the trailer 100 in an inclined configuration so that the front end 312 is positioned slightly higher than the rear end 314, so that the liquid can flow by gravity towards the sump(s).

[0040] In some embodiments, the container may be suitable for storing gases, liquids or other flowable materials. In some embodiments, the trailer 100 may be configured to support other removable containers, such as shipping containers, or may define a compartment for accommodating pallets of goods, such as bulk goods or produce, for example.

[0041] In some embodiments, the trailer chassis 110 may extend substantially the entire length of the container 310 and may be configured to support the load 300, such a container 310 along its entire length. In some embodiments the trailer chassis 110 may comprise the skid plate 340 and kingpin 342. This arrangement may be preferred for transporting removable containers, such as shipping containers, for example.

[0042] Referring now to Figure 2, which shows atop view of the trailer 100 with the load 200 removed, the chassis rails 120, 130 may comprise a pair of elongate chassis rails extending parallel to the forward direction of travel of the trailer 100, and spaced apart to define therebetween an inboard region or section 140 of the trailer chassis 110. The pair of elongate chassis rails may alternatively be referred to as first and second chassis rails 120, 130, and may extend from a front end 112 of the trailer chassis 110 to a rear end 114 of the trailer chassis110.

[0043] In some embodiments, the trailer 100 comprises a plurality of cross members 210, 220, 230, 240, 250 disposed in the inboard section 140 to connect the chassis rails 120, 130 and to provide torsional stiffness of the trailer chassis 110. Vertical movement of the individual wheels or axles of the trailer 100, for example due to imperfections in the road surface, is transmitted through the suspension system into the trailer chassis 110. These movements of the individual wheels or axles result in different parts of the trailer chassis 110 receiving different relative loads, causing the trailer chassis 110 to experience a twisting force that is resisted by its torsional stiffness. While five cross members 210, 220, 230, 240, 250 are shown, it should be understood that any suitable number, combination, or orientation of cross members may be used depending on the torsional stiffness required, and to comply with applicable engineering and/or safety standards, for example.

[0044] The frontmost axle 404 has a centreline 405, the middle axle 406 has a centreline 407, and the rearmost axle 402 has a centreline 403 (as shown in Figure 2). The wheelbase length for the trailer 100 is defined by distance between the centreline 407 of the middle axle group 406 and the centre of the kingpin 342, and may be approximately 6759mm as shown in Figure 1. A longer wheelbase means that the trailer frame 110 will exhibit a greater amount of torsional deflection between its ends for a given angle of twist, compared to a shorter wheelbase.

[0045] Continuing to refer to Figure 2, the fifth-wheel coupling 500 comprises a top plate 504 with guide portions 506, 508 either side of a socket 510. The guide portions 506, 508 extend rearward to guide a kingpin of a trailer to be towed into the socket 510, wherein the kingpin is retained by a locking mechanism such as a latch. In some embodiments, portions of the top plate 504, for example the guide portions 506, 508, extend beyond the rear end 114 of the trailer chassis 110. An example of a suitable fifth-wheel coupling 500 is the "800 Maxi" manufactured by D'Angelo Engineering.

[0046] The fifth-wheel coupling 500 is attached to the trailer chassis 110 in the inboard section 140 between the chassis rails 120, 130. When a kingpin of a towed trailer is connected to the fifth-wheel coupling 500 as described above, the fifth-wheel coupling 500 is capable of pivoting about a centre 502 to accommodate pitching and yawing movement of the towed trailer, and prevents or at least reduces rolling of the towed trailer. The kingpin of the towed trailer is generally in line with the centre 502 when the kingpin is received in the socket 510.

[0047] A distance, X, between the centre 502 and the centreline 403 of the rearmost axle 402 (measured in a horizontal direction along a length of the chassis) may be less than 700mm, between 1mm and 700mm, between 300mm and 650mm, between 500mm and 600mm, or between 550mm and 600mm. In some embodiments, the distance X is approximately 581mm. The centre 502 may be rearward of the centreline 403. In some embodiments, the centre 502 is substantially in line with the centreline 403.

[0048] The first chassis rail 120 comprises a front end 122 disposed opposite a rear end 124, and a top portion 126 disposed opposite a bottom portion 128. Similarly, the second chassis rail 130 comprises a front end 132 disposed opposite a rear end 134, and a top portion 136 disposed opposite a bottom portion 138.

[0049] Continuing to refer to Figure 3, with further reference to Figure 1, the top portions 126, 136 of the chassis rails 120, 130 are connected to a lower portion of the load 300. The fifth wheel coupling 500 is positioned at least partially within the inboard section 140 below the lower portion of the load 300 and above a height of the rear axle 402 so that the top plate 504 of the fifth-wheel coupling 500 rests below the top portions 126, 136 of the chassis rails 120, 130. By disposing the fifth-wheel coupling 500 in the inboard section 140, the forces transmitted to the fifth-wheel coupling 500 are transmitted to the trailer 100 as close as possible to the roll axis of the trailer 100. This may reduce the contribution of said forces to roll experienced by the trailer 100 and may assist with maintaining stability when the trailer is part of a vehicle that is changing direction.

[0050] In some embodiments, the fifth-wheel coupling 500 is disposed at a level that is less than or equal to a level of a top of wheels 412 coupled to the rearmost axle 402. For example, the level of the top plate 504 may be between 700mm and 1300mm above the ground when the fifth wheel coupling 500 is in a laden condition (i.e. with a kingpin from a towed trailer received in socket 510). In some embodiments, the level of the top plate 504 in the laden condition is approximately 988mm. The level of the top plate 504 may be between 700mm and 1300mm above the ground when the fifth-wheel coupling 500 is in an un-laden condition. In some embodiments, the level of the top plate 504 in the un-laden condition is approximately 1010mm.

[0051] In order to accommodate a fifth-wheel coupling under the load, the load could be raised to a higher level, but that would raise the centre of gravity and reduce stability under pitching and rolling moments. However, by placing the fifth-wheel coupling 500 so that its top plate 504 rests below the top portions 126, 136 of the chassis rails 120, 130, and in some embodiments at a level that is less than or equal to the level of the top of wheels 412, the load 300 does not need to be raised to accommodate the fifth-wheel coupling 500. This allows the centre of gravity of the trailer 100 carrying load 300 to be maintained at a similar height to a conventional trailer and load.

[0052] Turning to Figures 4 and 5, the trailer chassis 110 and its various structural elements shall now be described in more detail. Figure 4 shows a similar view to Figure 2, with the wheels and axles additionally removed to better show the trailer chassis 110. Figure 5 is a perspective view of the trailer as shown in Figure 4.

[0053] The first and second chassis rails 120, 130 may be made from steel or a similar material with appropriate weight, cost, ease of manufacture, durability, and strength characteristics. For example, reducing weight improves fuel consumption of the vehicle. The chassis rails 120, 130 may be made from extrusions or an assembly of smaller pieces, such as steel plates. An example of a suitable material for the chassis rails 120, 130 is Grade 350 mild steel. Another example of a suitable material is Grade 700 steel such as "Strenx700" high-strength structural steel. A suitable section of steel is 6mm thick plate, compliant with Australian Standard AS 3678.

[0054] The chassis rails 120, 130 comprise attachment members 150 to facilitate attachment of cross members and other structure to provide strength and torsional stiffness to the trailer chassis 110, and also to provide locations for supporting and attaching other components such as axles, hydraulic systems, pneumatic systems, and/or wiring systems.

[0055] In some embodiments, the attachment members 150 comprise flanges and/or plates 152 extending from the chassis rails 120, 130 at various points along the length of the chassis rails 120, 130. The cross members 210, 220, 230, 240, 250 are connected to selected flanges 152 by welding and/or by fasteners. The flanges 152 may extend from the top portions 126, 136, and/or from the bottom portions 128, 138, and in doing so, may also provide bending resistance in certain directions. An example of suitable material for the flanges 152 is Grade 350 mild steel, and a suitable section of steel is 10mm thick plate, compliant with Australian Standard AS 3678.

[0056] In some embodiments, the chassis rails 120, 130 further comprise gussets or stiffeners .

The gussets or stiffeners 154 may comprise plates disposed at various points along the length of the chassis rails 120, 130, wherein the gussets 154 may extend from the top portions 126, 136 to the bottom portions 128, 138. Some embodiments of the gussets 154 may only extend partly between or from the top portions 126, 136 and the bottom portions 128, 138. These gussets 154 provide bending resistance in certain directions and improve the torsional stiffness of each chassis rail 120, 130. An example of suitable material for the gussets 154 is Grade 350 mild steel, and a suitable section of steel is 10mm thick plate, compliant with Australian Standard AS 3678.

[0057] In addition to providing torsional stiffness, the cross members 210, 220, 230, 240, 250 act as bracing members for the trailer chassis 110. An example of suitable material for the cross members 210, 220, 230 is steel, such as 100mm x 100mm hollow section made from Grade 350 steel with a 6mm wall thickness, compliant with Australian Standard AS 3678. Other sections of steel may be used, such as angles or channels, if structurally and functionally suitable. In some embodiments, the cross members 210, 220, 230, 240, 250 may have flanges and/or plates 152 extending therefrom to provide attachment points for ancillary structure and components without affecting the structural properties of the cross members.

[0058] Each chassis rail 120, 130 comprises a front extremity at their front ends 122, 132, and a rear extremity at their rear ends 124, 134. The length of the chassis rails 120, 130, as measured from the front to rear extremities, may be in the range of 2000mm to 7000mm, 3000mm to 6000mm, or 4000mm to 5000mm. In some embodiments, the length is approximately 4569mm.

[0059] Each chassis rail rear end 124, 134 comprises a rebate or recess portion 125, 135 extending from the rear extremity of each chassis rail rear end 124, 134 in a forward direction. The rebate portions 125, 135 accommodate yaw movement of a towed trailer that would otherwise interfere with the chassis rails 120, 130 when the towed trailer is connected to the fifth-wheel coupling 500.

[0060] The support structure 200 for supporting the fifth-wheel coupling portion 500 is disposed in the inboard section 140 to support the fifth-wheel coupling 500, and in some embodiments, spans the inboard section 140. In some embodiments, at least part of the support structure 200 is disposed at the chassis rail rear ends 124, 134. The support structure 200 may comprise supporting members 202 extending inwardly towards each other from the chassis rails 120, 130 at or near the rear ends 124, 134. An example of suitable material for the supporting members 202 is steel, such as 50mm x 50mm hollow section made from Grade 350 steel with a 6mm wall thickness, compliant with Australian Standard AS 3678.

[0061] The support structure 200 comprises abase plate 204, which in some embodiments is disposed towards the bottom portions 128, 138 of the rails 120, 130 so as to provide adequate clearance for the fifth-wheel coupling 500 to receive the kingpin of a trailer to be connected. The fifth-wheel coupling 500 is connected to the base plate 204. In particular, the fifth-wheel coupling 500 (such as the D'Angelo 800 Maxi fifth-wheel coupling) may comprise pedestals 512 which can be welded to the base plate 204. The base plate 204 may define a hole or cut out 205

(see Figure 6) to reduce the weight of the base plate 204. The hole 205 may be located between the pedestals 512 to provide ease of access to the fifth-wheel coupling 500 from below.

[0062] The support structure 200 may further comprise cross members 240, 250 which together with supporting members 202 and base plate 204 act to stiffen and strengthen the trailer chassis rear end 114 and support the fifth-wheel coupling 500. In the embodiment of Figures 4 and 5, cross members 240, 250 span the inboard section 140 to connect the chassis rail rear ends 124, 134. An example of suitable material for the cross members 240, 250 is steel, such as 100mm x mm hollow section or 50mm x 50mm hollow section made from Grade 350 steel with a 6mm wall thickness, compliant with Australian Standard AS 3678.

[0063] The cross member 250 may be the rearmost cross member and be located rearward of the connection between the fifth-wheel coupling 500 and the base plate 204. Reference is drawn to Figure 3, which shows the location of the cross member 250 relative to the connection of the fifth-wheel coupling 500 to the base plate 204 via the pedestals 512.

[0064] The trailer chassis rear end 114 comprises a rear structure 160, as shown in Figure 6. The cross member 250 may provide support for the rear structure 160 of the trailer chassis 110. The rear structure 160 comprises a bumper, lights, registration/licence plate holder, and guards.

[0065] In some embodiments, the rear structure 160 comprises the rear extremity. The length of the trailer 100 is measured as the distance from the frontmost extremity to the rear extremity, which in some embodiments of the trailer 100 is between 8m and 13m, or between 9.5m and 12m. In some embodiments, the length of the trailer 100 is approximately I1m, or approximately 10.3m. A length from the rear extremity to the kingpin 342 may be between 8m to 1Om. In some embodiments the length from the rear extremity to the kingpin 342 is approximately 9.1m.

[0066] As noted previously, the trailer 100 maybe connected to a preceding trailer by a dolly to form a trailer combination. In some embodiments, the trailer combination comprises a dolly connected to the fifth-wheel coupling of the trailer.

[0067] Referring now to Figure 7, a dolly 600 is shown comprising a dolly chassis 610 for supporting a trailer to be towed, a set of axles 640 coupled to the dolly chassis 610, and a fifth wheel coupling 650 coupled to the dolly chassis 610 to receive a kingpin of the trailer to be towed. In some embodiments, the dolly may further comprise a drawbar 700 which connects the dolly chassis 610 to a preceding trailer.

[0068] In some embodiments, the dolly chassis 610 comprises first and second dolly chassis rails 620, 630, and is connected to the drawbar 700 by a pivoted connection 702. The drawbar 700 comprises a kingpin 742 which allows the dolly 600 to be connected to the fifth-wheel coupling of a prime mover or the fifth-wheel coupling 500 of a preceding trailer 100, for example as part of a road train vehicle. A landing gear or set of legs similar to legs 330 may be installed on the drawbar 700 and offset from the pivoted connection 702 to support the drawbar 700 while connecting the dolly 600 as described above.

[0069] The set of axles 640 comprises a rearmost axle 642 and a frontmost axle 644.

[0070] Figures 8 and 9 show an embodiment of the drawbar 700. In some embodiments, the drawbar 700 comprises a drawbar chassis 710 with first and second drawbar chassis rails 720, 730. The first and second drawbar chassis rails 720, 730 may be elongate members, and may be made from steel or a similar material with appropriate weight, cost, ease of manufacture, durability, and strength characteristics. An example of a suitable material for the rails 720, 730 is Grade 350 steel, and a suitable section is 100mm parallel flange channel (PFC). Other sections of steel may be used, such as angles or hollow sections, if structurally and functionally suitable.

[0071] A plurality of bracing members 800 maybe arranged between the rails 720, 730 to provide strength and stiffness without adding excessively to the weight of the drawbar 700. In some embodiments, the plurality of bracing members 800 comprises six bracing members 810, 820, 830, 840, 850, 860 which brace the rails 720, 730, although it should be understood that any number, combination, or orientation of bracing members 800 may be used depending on the torsional stiffness required, and to comply with applicable engineering and/or safety standards, for example.

[0072] The bracing members 800 may be made from steel or a similar material with appropriate weight, cost, ease of manufacture, durability, and strength characteristics. An example of a suitable material for the bracing members 800 is Grade 350 steel, and a suitable section is 100mm parallel flange channel (PFC). Other sections of steel may be used, such as angles or hollow sections, if structurally and functionally suitable. The bracing members 800 may each be welded to the rails 720, 730, and/or connected by mechanical fasteners such as bolts or rivets.

[0073] A drawbar top plate 704 and a drawbar skid plate 740 may be arranged to sandwich the rails 720, 730 and the bracing members 800 therebetween, particularly in embodiments of the drawbar chassis 710 where similarly sized steel sections are used for the rails 720, 730 and for the bracing members 800 so that their top and bottom surfaces are aligned in a flat plane. Other components such as hydraulic systems, pneumatic systems, and/or wiring systems may be stored in or pass through the spaces formed between the rails 720, 730 and the bracing members 800.

[0074] The drawbar chassis 710 has a front end 712 and an opposite rear end 714. The drawbar top plate 704 and the drawbar skid plate 740 are connected to the first and second drawbar chassis rails 720, 730, for example by welding. The kingpin 742 is connected to the drawbar skid plate 740 and is disposed at the front end 712. An example of a suitable material for the drawbar top plate 704 and the drawbar skid plate 740 is Grade 700 steel such as "Strenx" high-strength structural steel, and a suitable section is 8mm thick plate. The skid plate 740 may have a fold at the front end 712 (or slightly angled frontmost portion) to provide improved lead-in for the drawbar 700 during the coupling manoeuver with the trailer 100.

[0075] The drawbar 700 may further comprise a drawbar connection assembly 750, disposed at the rear end 714. The drawbar connection assembly 750 comprises an arm which pivotally engages with the dolly chassis 610 to form the pivot connection 702. In some embodiments, the drawbar connection assembly 750 comprises a pair of spaced-apart arms 752, 754 to provide more torsional rigidity at the pivot connection 702. The arms 752, 754 are connected to remote ends of a bar 756 connected to the rear end 714. Supporting members 758, 760 may connect remote ends of the bar 756 to the drawbar chassis 710 to form a triangulated structure which braces the arms 752, 754 and bar 756 to resist forces transmitted through the pivot connection 702.

[0076] The drawbar connection assembly 750 may be made from steel or a similar material with appropriate weight, cost, ease of manufacture, durability, and strength characteristics. An example of a suitable material for the arms 752, 754 is Grade 400 steel, and a suitable section is 102mm x 76mm hollow section with 6mm wall thickness. An example of a suitable material for the bar 756 and the supporting members 758, 760 is Grade 400 steel, and a suitable section is 100mm x 100mm hollow section with 6mm wall thickness. Other sections of steel may be used, such as angles or channels, if structurally and functionally suitable. The various components of the drawbar connection assembly 750 may each be welded together, and/or connected by mechanical fasteners such as bolts or rivets.

[0077] The drawbar 700 may be between approximately 2000mm and 5000mm in length, as measured from a frontmost extremity at the front end 712 to the centre of the pivot connection 702. In some embodiments, the drawbar 700 has a length of around 2500mm. The PBS sets a maximum allowable length for each Class and Level of a road train vehicle comprising the drawbar 700 and trailer 100. Consequently, a shorter length of drawbar 700 allows for increased wheel spacing of the adjoining trailer, which spreads the weight of the load 300 transported on the trailer 100 over a larger area. Furthermore, the weight of the drawbar 700 affects the amount of load that can be carried. A lighter drawbar means a greater proportion of the road train vehicle's weight can be assigned to the load. In some embodiments, the drawbar 700 may weigh between 200kg and 500kg, between 250kg and 300kg, or approximately 264kg, for example.

[0078] The arms 752, 754 may be spaced apart by a distance in the range of 500mm to 2000mm, 800mm to 1200mm, or approximately 1000mm.

[0079] Referring to Figures 7 and 9, embodiments of the drawbar 700 are configured to substantially extend in a straight line between the drawbar chassis front and rear ends 712, 714. This may contribute towards lowering the centre of gravity of the trailer combination, although it is envisaged that some embodiments may comprise a small step or angulation between the front and rear ends 712, 714 as required. For operation in Australia, some embodiments of the kingpin 742, fifth-wheel coupling 500, and drawbar 700 are designed to comply with AS 4968.1.

[0080] Embodiments of the trailer 100 maybe connected to a prime mover 900 to form an articulated lorry or semi-trailer truck, for example as shown in Figure 10. The prime mover 900 may be a truck or other type of tractor unit capable of hauling a towed load. For example, different configurations of the Kenworth K200 truck can have three driven rear axles. Other suitable prime movers include the Volvo FH or Volvo FM series of trucks or Mack tri-drive trucks.

[0081] The semi-trailer truck may comprise the prime mover 900 towing a single trailer, such as trailer 100. In some embodiments, the semi-trailer truck may also be referred to as a road train, comprising the prime mover 900 towing a plurality of trailers. The plurality of trailers comprises a rearmost trailer, and is arranged so that a preceding trailer tows a following trailer, and so on. For example, the prime mover 900 may tow two, three, or four trailers. All or some of the plurality of trailers may comprise one of the trailer 100. In some embodiments, the rearmost trailer may comprise a conventional trailer with a kingpin connector.

[0082] The trailers 100 may be directly connected to each other by a B-type coupling, for example in a B-double or B-triple wherein the kingpin of the following/towed trailer connects to a fifth-wheel coupling on the rear of the preceding/leading trailer. The B-type coupling is a fifth wheel or turntable coupling that controls the transfer of roll and weight loads between the trailers.

[0083] In some embodiments, the trailers 100 may be indirectly connected to each other via a conventional dolly, for example. The kingpin of the towed trailer may be connected to a fifth wheel coupling on the dolly, and the dolly may be connected to a leading trailer by a drawbar with an A-type coupling, for example in an A-double or A-triple configuration. Alternative trailer configurations may be a roll-couple A-triple or quad or quin. However, conventional A type couplings are drawbar based couplings (simple pinned connections), and typically are not designed to absorb or control the transfer of roll or weight loads between the trailers or dollies.

[0084] In some embodiments, the dolly is connected to the leading trailer by the drawbar 700 which is configured to connect to a B-type coupling with a kingpin and fifth wheel coupling. This allows for better control of the transfer of roll and weight loads between the trailers 100 in comparison with dollies with conventional A-type couplings..

[0085] In some embodiments, the semi-trailer truck may comprise the prime mover 900 towing the plurality of trailers, wherein the plurality of trailers are connected to each other by A or B type couplings, to form a vehicle such as an AB-triple or BAB-quad. The road train's ability to safely change direction, for example when changing lanes or when suddenly swerving to avoid an obstacle, is influenced by the number and configuration of the trailers in the road train.

[0086] Referring now to Figure 10, embodiments of the trailer 100 and dolly 600 maybe connected to form a triple road train vehicle 1000, comprising the prime mover 900 towing a first trailer 1100, a second trailer 2100, and a rearmost or third trailer 3100. In some embodiments, the second trailer 2100 is connected to the first trailer 1100 by a first dolly 1600, and the third trailer 3100 is connected to the second trailer 2100 by a second dolly 2600. In some embodiments, the first trailer 1100 and the second trailer 2100 each comprise ones of the trailer 100, comprising the fifth-wheel coupling 500 at its rear end. The third trailer 3100, being the rearmost trailer, may not require the fifth-wheel coupling 500 at its rear end, unlike trailer 100, and may comprise a conventional trailer with kingpin connector. However, in some embodiments the third trailer 3100 may comprise one of the trailer 100.

[0087] The first dolly 1600 comprises a first drawbar 1700, similar to drawbar 700, comprising a first kingpin 1742 configured to engage with the fifth-wheel coupling 1500 of the first trailer 1100. The second dolly 2600 comprises a second drawbar 2700, similar to drawbar 700, comprising a second kingpin 2742 configured to engage with the fifth-wheel coupling 2500 of the second trailer 2100.

[0088] For convenience, reference numerals for the triple road train vehicle 1000 may henceforth be taken to refer to similarly numbered features of the embodiments of the trailer 100 and dolly 600 described herein. For example, the first and second drawbars 1700, 2700 are to be read as having the same features and advantages of the drawbar 700, unless otherwise noted. Similarly, the fifth-wheel coupling 1500, 2500 is to be read as having the same features and advantages of the fifth-wheel coupling 500, unless otherwise noted.

[0089] The use offifth-wheel couplings 1500, 2500 in the vehicle 1000 may improve the vehicle's performance under the PBS category "High Speed Transient Offtracking" (HSTO), when compared to an equivalently sized and loaded conventional vehicle wherein the trailers are connected by conventional drawbars with A-type couplings. There may also be a similar improvement in performance under the PBS category "Rearward Amplification" (RA).

[0090] HSTO is defined as the lateral distance that the rearmost axle on the rearmost trailer tracks outside the path of the steering axle of a vehicle in a sudden evasive manoeuvre, such as when swerving to avoid an obstacle. RA is defined as the ratio of lateral acceleration of the truck steering input to the lateral acceleration of the last trailer unit. A higher RA may lead to the vehicle's trailers undergoing a "whip crack" motion, which is typically the result of a sudden lane change manoeuvre. Higher RA values indicate a greater likelihood of rear trailer rollover.

[0091] The use offifth-wheel couplings 1500, 2500 to connect the trailers of the vehicle 1000 may limit or reduce the likelihood and amount of whip and jack-knifing during a lane change or hard braking, as fifth-wheel couplings are able to better accommodate vertical movement, pitch, roll, and yaw moments compared to the A-type or pin connection of a conventional dolly. The advantages may be more significant on longer vehicles such as triple or quad road trains, where the whip crack effect can be more pronounced. Other advantages of usingfifth-wheel couplings 1500, 2500 to connect the trailers of the vehicle 1000 may also include a smaller turning circle, which is a key consideration when determining what type of roads the vehicle 1000 can access.

[0092] Vehicles assessed under the PBS are classified into one of four levels in accordance with the National Transport Commission's (NTC) 2008 Standards and Vehicle Assessment Rules ("the NTC Rules"). The NTC's 2007 PBS Network Classification Guidelines ("the NTC Guidelines") stipulate that a vehicle approved at a particular level is eligible to operate on the road network of the same classification level or higher, subject to road manager approval.

[0093] While vehicle length is an important factor in considering access to particular road networks, vehicle length is not the only factor in determining access. For example, a longer vehicle with more articulation points can complete the same radius turn as a shorter vehicle with fewer articulation points. Improved articulation may be provided by thefifth-wheel couplings 1500, 2500 as described above. Consequently, the NTC Guidelines further identify Class A and Class B vehicles under the PBS, wherein Class B vehicles can exceed the lengths stipulated for Class A vehicles. Vehicles under PBS Levels 2-4 can be further classified as either Class A or Class B vehicles. There is no Class B for PBS Level 1.

[0094] Class A vehicles have the following lengths and road network access. A PBS Level 4 vehicle is typically a 53.5 metre (maximum) long Type 2 road train, and is limited to the 53.5 metre Type 2 road train network. A PBS Level 3 vehicle is typically a 36.5 metre (maximum) long Type 1 road train, and may access the Type 2 road train network as well as access the 36.5 metre Type 1 road train network. A PBS Level 2 vehicle is typically a 26 metre (maximum) long B-double, and may access the aforementioned road train networks as well as access the 26 metre B-double network. A PBS Level 1 vehicle is typically a 19 metre (maximum) long prime mover and trailer, and may access the aforementioned road networks as well as access the general public road network.

[0095] Class B vehicles have the following lengths. A PBS Level 4 vehicle typically measures between 53.5 metres and 60 metres. A PBS Level 3 vehicle typically measures between 36.5 metres and 42 metres. A PBS Level 2 vehicle typically measures between 26 metres and 30 metres.

[0096] A vehicle that exceeds the upper length in a level may still be approved for use on that level's corresponding road network, pending an individual route assessment as per the NTC Guidelines. For example, a 31m long vehicle can still be approved for use on PBS Level 2 Class B roads.

[0097] In consideration of road network accessibility, it is desirable for transport operators to have their vehicles capable of accessing as many road networks as possible for that vehicle. This allows transport operators to reduce the need to take longer or less direct routes as a result of not being allowed to access particular roads.

[0098] Continuing to refer to Figure 10, the triple road train vehicle 1000 is a type of road train called a roll-coupled PBS A-triple which is categorised as a Class 2 Heavy Vehicle under the Heavy Vehicle National Law (HVNL).

[0099] Typically, a triple road train such as the vehicle 1000 is classified as a PBS Level 4 vehicle, as the length of the vehicle exceeds the 42m limit. However, in some embodiments, the length of the vehicle 1000 is approximately 42m or less, as measured from a front extremity at the front of the prime mover 900 to a rear extremity at the rear of the rearmost trailer, which in Figure 10 is the trailer 3100. The reduction in length may be down to the length of the drawbars 1700, 2700 being shorter than conventional drawbars, as previously disclosed herein. Furthermore, locating the fifth-wheel couplings 1500, 2500 inside the lengths of the trailers 1100, 2100 may contribute to reducing the spacing between adjoining trailers, thereby shortening the overall length of the vehicle 1000.

[0100] Notably, as embodiments of the vehicle 1000 have a maximum length that falls within the 42m limit for PBS Level 3 Class B vehicles, said embodiments of the vehicle 1000 may access the Type 2 road train network as well as access the 36.5 metre Type 1 road train network.

[0101] In general, the use of B-type connections such as fifth-wheel couplings provides various advantages as disclosed herein over the conventional dolly (A-type pin) connections. For road train vehicles seeking to obtain the advantages associated with the B-type connection, existing B-type trailers comprise a fifth-wheel coupling on a rear section of a towing/preceding trailer. This rear section occupies a large portion of the towing trailer's length to provide space for the towed/following trailer to connect to the fifth-wheel coupling. As a result, the towing trailer has a reduced load-carrying area. This is evident on a conventional B-triple or an AB-triple.

[0102] By using the fifth-wheel couplings 1500, 2500 with the dollies 1600, 2600, the towing trailer's load-carrying area is able to be maintained, similar to a conventional A-triple arrangement. The vehicle 1000 uses its length more efficiently than a conventional B-triple or a conventional AB-triple of equivalent length, as the connection between its trailers occupies less space, allowing a greater proportion of its length to be used for carrying load. Consequently, in some embodiments, the vehicle 1000 is able to carry between 15% to 25% more load than a conventional B-triple or a conventional AB-triple of equivalent length.

[0103] It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims (24)

CLAIMS:

1. A trailer suitable for a road train vehicle, the trailer comprising:

a trailer chassis for supporting a load to be transported;

a set of axles coupled via a suspension system to the trailer chassis and positioned towards a rear end of the trailer chassis to transfer a weight of the load to the ground, wherein each axle in the set of axles is arranged perpendicular to a forward direction of travel of the trailer; and

a fifth-wheel coupling coupled to the trailer chassis to receive a kingpin of an adjoining trailer, wherein the fifth-wheel coupling is disposed rearwardly of a rearmost axle of the set of axles and is coupled to the trailer chassis via a support structure that is fixedly attached to or forms part of chassis rails of the trailer chassis.

2. The trailer of claim 1, wherein the chassis rails comprise a pair of elongate chassis rails extending parallel to the forward direction of travel of the trailer, and spaced apart to define therebetween an inboard section of the trailer chassis.

3. The trailer of claim 1 or claim 2, wherein a top portion of each of the chassis rails is connected to a lower portion of the load, and wherein a top plate of the fifth-wheel coupling is positioned to rest below the top portion.

4. The trailer of any one of claims I to 3, wherein the fifth-wheel coupling is disposed at a level that is less than or equal to a level of a top of wheels coupled to the rearmost axle.

5. The trailer of any one of claims 1 to 4, wherein each of the chassis rails comprises a chassis rail rear end disposed at the rear end of the trailer chassis, and wherein at least part of the support structure is disposed at the chassis rail rear end.

6. The trailer of any one of claims I to 5, wherein the load includes a liquid container with drainage means comprising a sump.

7. The trailer of claim 6, wherein the liquid container comprises a container front end opposite to and inclined from a container rear end, and wherein the sump is located forward of the container rear end.

8. The trailer of claim 7, wherein the sump is disposed at the container rear end and vertically in line with wheels supported by the rearmost axle.

9. The trailer of any one of claims I to 8, wherein a portion of the fifth-wheel coupling extends beyond the rear end of the trailer chassis.

10. The trailer of claim 9 when dependent on claim 3, wherein the portion of the fifth-wheel coupling that extends beyond the rear end of the trailer chassis comprises rearmost portions of the top plate of the fifth-wheel coupling.

11. The trailer of any one of claims 2 to 10 when dependent on claim 2, further comprising a plurality of cross members disposed in the inboard section to connect the chassis rails and to provide torsional stiffness of the trailer chassis.

12. The trailer of any one of claims 2 to 11 when dependent on claim 2, wherein the support structure is disposed in the inboard section and spans the inboard section to support the fifth wheel coupling.

13. The trailer of any one of claims 2 to 12 when dependent on claim 2, wherein the support structure comprises a base plate disposed towards a bottom portion of each of the chassis rails, wherein the bottom portion is opposite to the top portion of each of the chassis rails.

14. The trailer of any one of claims 11 to 13, wherein the plurality of cross members comprises a rearmost cross member which forms part of the support structure.

15. The trailer of claim 14 when dependent on claim 13, wherein the rearmost cross member is rearward of the fifth-wheel coupling connection to the base plate.

16. The trailer of claim 5 or any one of claims 6 to 15 when directly or indirectly dependent on claim 5, wherein each chassis rail rear end comprises a rebate portion extending from a rear extremity of the chassis rail rear end in a forward direction.

17. The trailer of claim 16, wherein the rebate portion accommodates yaw movement of a towed trailer that would otherwise interfere with the chassis rails when the towed trailer is connected to the fifth-wheel coupling.

18. The trailer of any one of claims 3 to 17, wherein the top plate is between 700mm and 1300mm above the ground.

19. The trailer of any one of claims I to 18, wherein a distance between a centre of thefifth wheel coupling and the rearmost axle is less than or equal to 700mm.

20. A trailer combination, comprising a dolly connected to the fifth-wheel coupling of the trailer of any one of claims 1 to 19, wherein the dolly comprises a drawbar.

21. The trailer combination of claim 20, wherein the drawbar comprises a kingpin coupled to a skid plate, wherein the kingpin is configured to engage with the fifth-wheel coupling.

22. A triple road train vehicle, comprising a prime mover towing a first trailer, a second trailer, and a third trailer;

wherein the second trailer is connected to the first trailer by a first dolly, and the third trailer is connected to the second trailer by a second dolly; and

wherein the first trailer and the second trailer are each the trailer of any one of claims 1 to 19.

23. The vehicle of claim 22, wherein the first dolly comprises a first drawbar, the first drawbar comprising a first kingpin configured to engage with the fifth-wheel coupling of the first trailer.

24. The vehicle of claim 22 or claim 23, wherein the second dolly comprises a second drawbar, the second drawbar comprising a second kingpin configured to engage with the fifth wheel coupling of the second trailer.

300, 310 102 312 314

104

110 1/10

120, 130 500

316, 318 342 340

200

330 404 406 402 320 414 412 400 Fig.1

120 414 140 412

112 414 412 114

210 220 230 240 500 502 504 506 402 404 510 250 2/10

406

508

414 412

414 412

130 403 X 405 407 Fig.2

112 114 405 403 502 120

122 210 220 126 230 124 500

504

512 250 3/10

128 404 402 240

414 412 400

X Fig.3

140 112 114

120 202

122 152 154 154 124 150 152 152 154

210 220 230 240 250 4/10

132 152 152 152 202 134 152 130 154 154 154 154

Fig.4

122 126 112 120 152 128 140 154 154 132 152

210 124 136 125 5/10

130 138 220

230 500 134 135 200 502 204 114 512 160

Fig.5

154 230 124 500 504 125

134 6/10

135 204 205 512 250 200

160

Fig.6

742 650 610 700 500 702 620, 630 7/10

160 330

644 642

640

Fig.7

700 750 752 702

758 740 710 720 800 756

714 712 8/10

730 810 742 760 820 830 840 850 860 702

754

Fig.8

710 750 704 800 756 712 714

702 9/10

740 752, 754 810 742 830 840 860 850 820 720, 730

Fig.9

1100 2100 3100 10/10

900 1500 1600 2500 2600 1700 2700

Fig.10