AU2018201357A1 - Compact Multi-articulated Goods-carrying Road Vehicle - Google Patents

Abstract

Abstract A combination vehicle for road transport of heavy goods. It comprises a prime mover at the front, a first semi-trailer comprising a first semi-trailer body adapted to carry 5 goods and attached directly to the prime mover, a second semi-trailer comprising a second semi-trailer body adapted to carry goods and attached directly to the rear of the first semi-trailer, and a trailer attached to said second semi-trailer so as to be towed behind the second semi-trailer. The trailer comprises a third semi-trailer body adapted to carry goods, a dolly mounted beneath the front of said third semi-trailer 10 body and having a dolly frame connected to the second semi-trailer body by a pivoting connection, and a drawbar assembly connecting the dolly frame to the rear of said second semi-trailer. The rear of said second semi-trailer is supported by either a single axle set or a tandem axle set. \rao cr r \O

Description

Compact Multi-articulated Goods-carrying Road Vehicle

Field of the Invention

This invention concerns multi-articulated goods-carrying road vehicles. It is particularly concerned with such vehicles having lengths of around 26 to 30 metres and GCM of 50.5 to 84.5 tonnes.

Background to the Invention

Multi-articulated goods-carrying road vehicles are types of heavy goods combination vehicles and typically comprise either a rigid truck or prime mover and two or more semi-trailers with or without converter dollies.

Articulated road vehicles come in many different sizes. In general, the longer the vehicle is, and the more wheels it has, the greater the load it can carry. However road authorities regulate the load upon, and spacing of, axles to control the loads placed on roads, and particularly bridges, so heavier and larger and longer vehicles are restricted in their access to certain roadways. However with increased length comes the disadvantage of reduced low-speed manoeuvrability which is required for travelling on existing roads, through intersections and turning in restricted spaces. To increase low-speed manoeuvrability for a given length of vehicle, the number of articulation points can be increased. But this generally reduces the high-speed stability/manoeuvrability of the vehicle as does shortening the length of the vehicle. There has historically thus been a trade-off between low-speed manoeuvrability (swept path) and high-speed stability/manoeuvrability.

The present invention provides an improvement in that trade-off for the types of vehicles concerned.

It is known for BA-triple road trains to have B-double lead units which are 25m and longer with a tri-axle axle group on the rear of the second semi-trailer. In contrast, the overall length break points for B-doubles that form a component of vehicles according this innovation are (nominally) 19m and (nominally) 20m. B-doubles up to 19m long are allowed general access to the road network under the current prescriptive regulations. Under the national Performance Based Standards (PBS) scheme, 20m long B-doubles may be granted Level 1 access to the road network, which in practice is effectively general access. However, for reasons of maneuverability, and to allow the rear axle set of the second semi-trailer to be only a single axle or a tandem axle configuration, the present invention is limited to vehicles where the B-double lead unit is no greater than 20m long.

Operators of multi-articulated goods-carrying road vehicles are often faced with the challenge of carrying the maximum, or near-maximum, load for only part of a journey and part load(s) for the remainder of the journey. This is common in, for example, collection of milk from farms for delivery to a processing factory, and delivery of bulk liquid fuels to customers or retail outlets. In many instances the collection and/or delivery points are only, or most efficiently, accessible by roads having a restriction on the length of the vehicle. This would normally preclude the use of longer vehicles on the desired route. The present invention provides a means by which this problem may be reduced.

In this specification, the following explanations apply to certain terms: a) A “heavy goods combination vehicle” is a heavy goods or road transport vehicle with at least one articulation point. b) A “semi-trailer” is a towed vehicle unit of a heavy goods combination vehicle whose means of attachment to the preceding vehicle unit (a prime mover, another semi-trailer, or a converter dolly) results in some of its vertical load being imposed on said preceding unit through a tow coupling and whose rear is supported by a single axle or multiple axle set (tandem, tri or quad axle set) located towards the rear. c) An “axle set” or “axle group” is either: - a group of axles, including their road wheels, beneath a vehicle unit in sufficiently close proximity to each other that their interactions with the pavement beneath are considered to overlap, or - a single axle including its road wheels mounted beneath a vehicle unit. A tandem axle set has two axles in close proximity and a tri-axle set has three axles in close proximity. Except for the steer axle, which has two wheels on each axle, the axle sets described in this specification will typically have four wheels on each axle so, for example, a tandem axle group has eight wheels. d) A “converter dolly” (also called a “dolly” or “forecarriage”) is a towed vehicle unit of a heavy goods combination vehicle whose tow coupling to the preceding vehicle unit (a rigid truck, a prime mover or another semi-trailer) results in little or none of its vertical load being imposed on said preceding vehicle unit through the tow coupling device (see below) and whose rear is supported by one or more single axles or a tandem or tri-axle set located at or near to the centre of the main load carrying area. The main load bearing or carrying area of a converter dolly usually incorporates a tow coupling device (quick release fifth wheel coupling or ballrace turntable, or both) so that the dolly may be mounted beneath the front of a semi-trailer body, thereby converting the semi-trailer into a “trailer”. In some countries a converter dolly is also known as a pivoting bogie, a dolly truck or a special truck. e) A “trailer” in a heavy goods combination vehicle is a towed vehicle unit that can be either a semi-trailer, or a combination of a converter dolly plus a semi-trailer. f) A “dog trailer” is a trailer with two axle groups of which the front axle group is steered by connection to the preceding vehicle unit by way of a drawbar assembly. g) A “prime mover” is a vehicle unit of a heavy goods combination vehicle built to tow a semi-trailer or a converter dolly, and is generally self-propelled. h) A “vehicle unit” is either a trailer, a semi-trailer, a converter dolly, or a motor vehicle. Thus a combination vehicle has a plurality of such vehicle units connected by an articulated coupling between each adjacent vehicle unit. i) A “coupling” is a mechanical assembly which provides connection between one vehicle unit (the leading vehicle unit) and another vehicle unit (the trailing vehicle unit) immediately behind. Typically a first part of the coupling is affixed to the leading vehicle unit, a second part of the coupling is affixed to the trailing vehicle unit and the first and second parts are releasably or permanently connected. j) A “coupling assembly” is an assembly of one or more couplings which connect a drawbar assembly to a vehicle unit immediately in front. k) A “fifth wheel coupling” or “fifth wheel assembly” provides a connection and means of articulation between a semi-trailer and the vehicle unit immediately ahead (the towing unit). The coupling consists of a kingpin on the front of the semi-trailer, and a horseshoe-shaped component called a fifth wheel on the rear of the towing unit. These two components when coupled are locked together using a quick release mechanism. When coupled the kingpin is free to rotate in the fifth wheel so providing articulation between the linked vehicle units. The fifth wheel can tilt fore and aft on a horizontal pin thus providing for vertical angulation between linked vehicle units. The fifth wheel is not free to tilt sideways thereby roll coupling the linked vehicle units. In practice there is some freeplay (or lash) in the connection allowing some sideways tilt under heavy sideways loads and usually evident only when the vehicle is close to rollover. l) A “ballrace turntable” is a type of coupling used to provide articulation between a semi-trailer and the vehicle unit immediately ahead. In contrast to a fifth wheel coupling it essentially provides no vertical or sideways tilt between the vehicle units thereby attached. m) A “drawbar assembly” is the portion of a dolly that connects the dolly’s frame or chassis to the vehicle unit in front for towing purposes. n) A “ringfeder” is a generic name (previously a trademark) commonly used worldwide to identify a type of automatic bolt coupling device (pin-type hitch/coupling) utilizing a swivelable cast bell portion with a horizontal opening and a machined pin which connects to a towing eye located on the front of a drawbar assembly. The connection between the towing eye and the pin is a “rotationally free joint” equivalent to a ball joint. The hitch point of a ringfeder coupling is at the longitudinal axis of the pin which engages with the towing eye of the drawbar. o) The Gross Combination Mass (or GCM) of a combination vehicle is a value specified by the manufacturer as being the maximum of the sum of the maximum laden mass of the prime mover plus the sum of the Axle Loads of all other vehicle units in the combination vehicle. p) A “B-double” is a multi-articulated goods carrying vehicle comprising a rear semi-trailer attached directly to a front semi-trailer, usually through a fifth wheel coupling, which is, in turn, attached directly to a prime mover, also usually through a prime mover. q) A “mini B-double” is a B-double vehicle which has a length no greater than 19 metres. r) A “tow coupling overhang” refers to the distance that a hitch point is located rearwards of the relevant axle centre or axle group centre. If the hitch point is located forwards of the relevant axle centre or axle group centre, then it can be considered as a negative tow coupling overhang.

Summary of the Invention

In one aspect, the invention provides a combination vehicle for road transport of heavy goods, said vehicle comprising: - a prime mover at the front, - a first semi-trailer comprising a first semi-trailer body adapted to carry goods and attached directly to the prime mover so as to be towed behind the prime mover, - a second semi-trailer comprising a second semi-trailer body adapted to carry goods and attached directly to the rear of the first semi-trailer, and - a trailer attached to said second semi-trailer so as to be towed behind the second semi-trailer, said trailer comprising: - a third semi-trailer body adapted to carry goods, - a dolly mounted beneath the front of said third semi-trailer body and having a dolly frame connected to the second semi-trailer body by a pivoting connection, and - a drawbar assembly connecting the dolly frame to the rear of said second semi-trailer, wherein the rear of said second semi-trailer is supported by either a single axle set or a tandem axle set.

Preferably the rear of said second semi-trailer is supported by only a single axle set. Preferably the tow coupling overhang at the rear of said second semi-trailer is no more than 950mm, more preferably no more than 750mm, and even more preferably no more than 650mm.

Preferably the length of its portion comprising the sum of said prime mover, said first semi-trailer and said second semi-trailer does not exceed 20 metres. More preferably it does not exceed 19 metres.

The rear of said first semi-trailer may be supported by only a single axle, Alternatively the rear of said first semi-trailer may be supported by only a tandem axle set.

Alternatively, the rear of said second semi-trailer may be supported by only a tandem axle set. In that situation the tow coupling overhang at the rear of said second semitrailer is preferably no more than 1500mm, more preferably no more than 1200mm, and even more preferably no more than 1100mm.

The length of the combination vehicle’s portion comprising the sum of said prime mover, said first semi-trailer and said second semi-trailer may not exceed 20 metres and may not exceed 19 metres.

The rear of said first semi-trailer may be supported by only a tandem axle set. Alternatively, the rear of said first semi-trailer may be supported by a tri-axle set.

The dolly frame may be supported by a tandem axle set, and the rear of said third semi-trailer supported by a tri-axle set, while the total length of said combination vehicle does not exceed 36.5 metres.

The dolly frame may be supported by a tandem axle set, and the rear of said third semi-trailer supported by a tandem axle set, and the total length of said combination vehicle does not exceed 30 metres.

The trailer may be supported by an arrangement of exactly three axles while the total length of said combination vehicle does not exceed 27.5 metres.

The dolly frame may be supported by a single axle set, while the rear of said third semi-trailer is supported by a single axle set, and the total length of said combination vehicle does not exceed 26 metres.

Brief Description of the Drawings

In order that the invention may be more fully understood there will now be described, by way of example only, preferred embodiments and other elements of the invention with reference to the accompanying drawings where:

Figure 1A is a side view of a heavy goods combination vehicle known in the prior art;

Figure IB shows a heavy goods combination vehicle according to a first embodiment of the present invention which incorporates the vehicle shown in Figure 1A;

Figure 1C shows a vehicle according to the invention which is modified from that shown in Figure IB;

Figure ID shows a vehicle according to the invention which is further modified from that shown in Figure 1C;

Figure IE shows a vehicle according to the invention which is further modified from that shown in Figure ID;

Figure IF shows a vehicle according to the invention which is further modified from that shown in Figure IE;

Figure 2A is a side view of another heavy goods combination vehicle known in the prior art;

Figure 2B shows a heavy goods combination vehicle according to another embodiment of the present invention which incorporates the vehicle shown in Figure 2A;

Figure 2C shows a vehicle according to the invention which is modified from that shown in Figure 2B;

Figure 2D shows a vehicle according to the invention which is further modified from that shown in Figure 2C;

Figure 2E shows a vehicle according to the invention which is further modified from that shown in Figure 2D;

Figure 3A is a side view of another heavy goods combination vehicle known in the prior art;

Figure 3B shows a heavy goods combination vehicle according to a further embodiment of the present invention which incorporates the vehicle shown in Figure 3A;

Figure 3C shows a vehicle according to the invention which is modified from that shown in Figure 3B;

Figure 3D shows a vehicle according to the invention which is further modified from that shown in Figure 3C;

Figure 3E shows a vehicle according to the invention which is further modified from that shown in Figure 3D;

Figure 3F shows a vehicle according to the invention which is further modified from that shown in Figure 3E;

Figure 4 is an enlarged copy of Figure IB;

Figure 5 is an enlarged copy of Figure 2B;

Figure 6 shows a further embodiment of the invention; and Figure 7 shows a further embodiment of the invention.

The drawings are schematics only and are not necessarily all to the same scale.

Discussion of Embodiments of the Invention

The combination vehicle 102 in Figure 1A is identified in Australia as having a “mini B-double” configuration. It is a road transport vehicle comprising a prime mover 113 to which is attached a first (or front) semi-trailer 114 followed by a second semitrailer 116. It is shown carrying two bulk liquid transport tanks, but these could alternatively be ISO shipping containers or other goods. The B-double vehicle 102 extends for a little less than 19 metres in length (but has a nominal length of 19m) and has a fully laden weight (GCM) of up to 57.5 tonnes.

The prime mover 113 has a pair of steering wheels 122 and a double-axle (tandem) rear axle group 124. The first semi-trailer 114 has its front supported by the prime mover 113 by means of a quick release fifth wheel coupling 132 and its rear is supported by a tandem rear axle group 126 having eight road wheels on a tandem axle set 138. The second semi-trailer 116 has its front supported by the rear of the first semi-trailer 114 by means of a quick release fifth wheel coupling 134 and its rear is supported by a tandem rear axle group 128.

The combination vehicle 104 in Figure IB, and enlarged in Figure 4, comprises the mini B-double 102 of Figure 1A together with a short dog-trailer 117 attached behind to form overall a BA-triple vehicle. The trailer 117 comprises a short third semitrailer 142 plus a single axle group dolly 143 which supports the front of the third semi-trailer 142. The rear of the third semi-trailer 142 is supported by a single-axle rear axle group 144. The dolly 143 has a single-axle group 145 with four road wheels. The dolly 143 pivots around a vertical axis 146 relative to the third semitrailer 142 by means of a ball race turntable 147. The dolly 143 is attached to the rear of the second semi-trailer 116 by a drawbar assembly 149 attached by a ringfeder coupling 148 at a hitch point 150 on the rear of the second semi-trailer 116. The BA-triple combination vehicle 104 in Figure IB extends for a little less than 26 metres in length (but has a nominal length of 26 metres) and has a GCM of up to 77.5 tonne. It can also operate at lower GCMs for greater road network access.

The combination vehicle 106 in Figure 1C comprises the mini B-double 102 of Figure 1A together with a dog trailer 118 attached behind to form a BA-triple vehicle 106. The trailer 118 is longer than the trailer 117 and comprises a third semi-trailer 152 plus a dolly 153 which supports the front of the third semi-trailer 152. The rear of the semi-trailer 152 is supported by a tandem-axle rear axle group 154 and the dolly 153 has a single-axle group. The semi-trailer 152, and the dolly’s drawbar assembly 159, in Figure 1C are both longer than the corresponding semi-trailer 142 and drawbar assembly 149 in Figure IB, so the BA-triple combination vehicle extends for a little less than 27.5 metres in length and has a GCM of up to 84.5 tonne.

The combination vehicle 108 in Figure ID comprises the mini B-double 102 of Figure 1A together with a dog trailer 119 attached behind to form a BA-triple vehicle. The trailer 119 is the same length as the trailer 118 in Figure 1C and, similarly, comprises a semi-trailer 162 plus a dolly 163 which supports the front of the semitrailer. But the rear of the semi-trailer 162 is supported by a single-axle rear axle group 164 and the dolly 163 has a tandem-axle group 165. The dolly 163 has eight road wheels on a tandem axle set 165. The vehicle 108 is the same length as the vehicle 106 in Figure 1C and has the same GCM.

The combination vehicle 110 in Figure IE comprises the mini B-double 102 of Figure 1A together with a dog trailer 120 attached behind. The trailer 120 is longer than the trailers 118 and 119 in Figures 1C and ID. The trailer 120 comprises a third semitrailer 172 plus a dolly 173 which supports the front of the semi-trailer 172. The semi-trailer 172 is longer than the semi-trailers 152 and 162. The rear of the semitrailer 172 is supported by a tandem rear axle group 174 and the dolly 173 also has a tandem-axle group. The semi-trailer 172 is longer than the semi-trailers 152 and 162. The BA-triple combination vehicle 110 reaches up to 30 metres in length and has a GCM of up to 91.5 tonne. It can also operate at lower GCMs for greater road network access.

The combination vehicle 112 in Figure IF comprises the mini B-double 102 of Figure 1A together with a dog trailer 121 attached behind. The trailer 121 is longer than the trailer 120 in Figure IE. The trailer 121 comprises a third semi-trailer 182 plus a dolly 183 which supports the front of the semi-trailer 182. The rear of the semi-trailer 182 is supported by a tri-axle rear group 184 and the dolly 183 also has a tandem-axle group. The entire BA-triple vehicle 112 reaches up to 36.5 metres in length and has a GCM of up to 97 tonne. It can also operate at lower GCMs for greater road network access.

For each of the embodiments shown in Figures 1C to IF, the respective dolly frame is attached to the second semi-trailer by a drawbar assembly attached by a ringfeder coupling at a hitch point on the rear of the second semi-trailer 114 in the manner described with reference to Figure IB. The length of the respective drawbars are generally different for each trailer but for some they can be the same, such as the drawbars shown in Figure ID and IE.

The B-double combination vehicle 202 in Figure 2A is a road transport vehicle having substantially the same configuration as the vehicle 102 in Figure 1A except that the rear of the second semi-trailer 216 is supported by only a single axle set 240.

The vehicle 210 comprises a prime mover 213 to which is attached a first semi-trailer 214, and a second semi-trailer 216 behind the first. It is again a little under 19 metres in length so is regarded as a mini B-double. Its GCM of 50.5 tonne is lower than the 57.5 tonne of mini B-double 102.

The combination vehicle 204 shown in Figure 2B, and enlarged in Figure 5, is a particularly preferred embodiment of the present invention. It is especially manoeuvrable at low speeds and especially stable at highway speeds. The trailer 217 attached behind the second semi-trailer 216 is the same as the trailer 117 in Figure IB. However an unusual feature of the vehicle 204 is that, although the prime mover has a tandem rear axle group 224 to provide the drive, and the first semi-trailer 214 is supported at its rear by a tandem axle set, the second semi-trailer 216 has only a single axle group at its rear. It makes possible a particularly short coupling rear overhang where the drawbar 249 is coupled by a ringfeder to the second semi-trailer 216. This is an important feature which contributes substantially to the high speed dynamic stability of the vehicle.

The drawbar of each dolly has a single ringfeder coupling connected to the rear of the second semi-trailer at a position some distance rearward of the centre of the rear axle group. That distance is commonly referred to as the “coupling rear overhang”. At the commencement of a high-speed turn, the hitch point moves laterally in a direction opposite to that of the turn. This causes the dolly to initially be steered to move in a direction opposite the intended turn direction. A short time later, as part of the normal sequence of events associated with the turn, the tow coupling point moves in the direction of the turn causing the dolly frame to be steered in the desired turn direction. This abrupt change of direction of the dolly associated with the initial reverse steer described above is often referred as “whip”. In some circumstances it can lead to rollover of the rear trailer.

By positioning a single rear axle well back on a semi-trailer and having the hitch point located sufficiently far forward of the rear of the semi-trailer, it is possible to have the hitch point forward of the centre of the axle or axle group and thus effectively a negative coupling rear overhang. That arrangement would satisfy the requirement of any requirement for a configuration to have less than some defined positive amount.

By using only a single axle group 228 on the rear of the second semi-trailer, and by mounting it well back, and by positioning the ringfeder coupling 248 as close as possible to the single axle group 228, it is possible to obtain a tow coupling overhang of less than 650mm. It has been found that such a small tow coupling overhang produces good stability in this vehicle, even though it is based on a B-double of only 19 metres in length. A tow coupling overhang of less than 750mm is also acceptable, but not preferred.

The combination vehicles shown in Figures 2C, 2D and 2E include trailers 218, 219 and 220 which are the same as the corresponding trailers 118, 119 and 120 described above for other embodiments. The particularly short coupling rear overhang present at the rear of the second semi-trailer in each of vehicles 204, 206, 208 and 210 provides better dynamic stability to all of those BA-triple versions.

The configuration of the B-double vehicle 302 shown in Figure 3A differs from the vehicle in Figure 1A in that it is nominally 20 metres long and has a tri-axle group 338 used on the rear of the first semi-trailer 314. Like the vehicle 102, it has a tandem axle set on the rear of the second semi-trailer 316. This permits the vehicle to have a greater total mass of up to 63 tonnes, although there is a reduced low-speed manoeuvrability.

The combination vehicle 304 shown in Figure 3B comprises the B-double 302 together with the dog trailer 317. The trailer 317 attached behind the second semitrailer 316 is the same as the trailer 117 in Figure IB. However as the second semitrailer 316 is supported at its rear by a tandem axle set 328, the coupling rear overhang for the trailer coupling is significantly greater than that in vehicle 204.

Nevertheless, by positioning the ringfeder coupling as close as possible to the tandem axle group 328, it is possible to obtain a tow coupling overhang of less than 1500mm.

The combination vehicles shown in Figures 3C, 3D, 3E and 3F include trailers 318, 319, 320 and 321 which are the same as the corresponding trailers 118, 119, 120 and 121 described above for other embodiments. The resulting respective vehicles are vehicle 304 having a total length of 26 metres and a maximum GCM of 83 tonne, vehicles 306 and 308 having a total length of 27.5 metres and a maximum GCM of 90 tonne, vehicle 310 having a total length of 30 metres and a maximum GCM of 97 tonne, and vehicle 312 having a total length of 36.5m and a maximum GCM of 102.5 tonne. These can also operate at lower GCMs for greater road network access consistent with load limits imposed by bridges.

The vehicle 604 shown in Figure 6 has a relatively simple configuration. It’s prime mover has a single axle drive wheel arrangement, the first semi-trailer 614 has a single axle 626 at its rear, the second semi-trailer 616 has a single axle 626 at its rear, and the trailer 617 has a single axle group 143 on the dolly and a single axle group 144 at its rear. The length of the mini B-double front portion is a little under 19 metres, the overall length of the vehicle 604 is a little less than 26 meters, and its GCM is up to 56.5 tonne.

The combination vehicle 704 shown in Figure 7 is generally similar in configuration to vehicle 204 shown in Figure 2B. The vehicle 704 is adapted to carry logs from forestry operations. The logs are held within U-shaped stanchions 788 and the logs may typically occupy one of the load spaces indicated by the rectangles 791 to 799. A significant feature is that the ringfeder coupling 748 is located 55cm forwards of the centre of the single axle group 728. In that arrangement the coupling has what would be considered a negative rear overhang, which is thus considered to be less than any positive rear overhang.

The conversion of the general access B-double to a BA-triple by way of the present invention requires, in the main, only addition of a tow-coupling (eg ringfeder) to the rear of the second semi-trailer and attachment of the rear trailer.

In order to make such a short BA-triple have acceptable stability and dynamics, amongst other things, the tow coupling overhang on the rear of the second semi- trailer must be as short as possible. This requires the axle group on the rear of the second semi-trailer to be a tandem with a small axle spread (close to 1250mm) or, preferably, a single axle. A tri-axle group on the rear of the second semi-trailer will not work acceptably because the tow coupling overhang will be much too long.

The overall lengths the BA-triple embodiments described above correspond to particular current vehicular rules in Australia as follows: (a) 26m: current national upper limit for the B-double road network (generally and under the PBS scheme - PBS Level 2, Road Network Access Class A), (b) 27.5m: current upper limit for B-doubles in Western Australia, (c) 30m: current upper limit for B-doubles under the PBS scheme (PBS Level 2, Road Network Access Class B) (d) 36.5m: current upper limit nationally for Type 1 road trains and road trains under the PBS scheme (PBS Level 3, Road Network Access Class A) (road trains include BA-triples).

Operators could then run the 19 metre and 20 metre B-doubles as general access vehicles and, when required, simply add the trailer and run as a BA-triple on the B-double road network.

The invention allows the operator of multi-articulated goods-carrying road vehicles to operate a B-double which is sufficiently small to have general access on the road system but to also have the ability to quickly and easily expand the capacity of the vehicle by adding a trailer. Even in the expanded BA-triple configuration, the embodiments at lengths of 26 metres, 27.5 metres, 30 metres and 36.5 metres still have wide access to the road network.

While the above description includes the preferred embodiments of the invention, it is to be understood that many variations, alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the essential features or the spirit or ambit of the invention.

It will be also understood that where the word “comprise”, and variations such as “comprises” and “comprising”, are used in this specification, unless the context requires otherwise such use is intended to imply the inclusion of a stated feature or features but is not to be taken as excluding the presence of other feature or features.

The reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that such prior art forms part of the common general knowledge.

Claims (20)

1. Claims

   1. A combination vehicle for road transport of heavy goods, said vehicle comprising: - a prime mover at the front, - a first semi-trailer comprising a first semi-trailer body adapted to carry goods and attached directly to the prime mover so as to be towed behind the prime mover, - a second semi-trailer comprising a second semi-trailer body adapted to carry goods and attached directly to the rear of the first semi-trailer, and - a trailer attached to said second semi-trailer so as to be towed behind the second semi-trailer, said trailer comprising: - a third semi-trailer body adapted to carry goods, - a dolly mounted beneath the front of said third semi-trailer body and having a dolly frame connected to the second semi-trailer body by a pivoting connection, and - a drawbar assembly connecting the dolly frame to the rear of said second semi-trailer, wherein the rear of said second semi-trailer is supported by either a single axle set or a tandem axle set.
2. 2. A combination vehicle according to claim 1 wherein the rear of said second semi-trailer is supported by only a single axle set.
3. 3. A combination vehicle according to claim 2 wherein the tow coupling rear overhang at the rear of said second semi-trailer is no more than 950mm.
4. 4. A combination vehicle according to claim 3 wherein the tow coupling overhang at the rear of said second semi-trailer is no more than 750mm.
5. 5. A combination vehicle according to claim 4 wherein the tow coupling overhang at the rear of said second semi-trailer is no more than 650mm.
6. 6. A combination vehicle according to any one of claims 1 to 5 in which the length of its portion comprising the sum of said prime mover, said first semi-trailer and said second semi-trailer does not exceed 20 metres.
7. 7. A combination vehicle according to claim 6 in which the length of its portion comprising the sum of said prime mover, said first semi-trailer and said second semitrailer does not exceed 19 metres.
8. 8. A combination vehicle according to any one of claims 1 to 7 wherein the rear of said first semi-trailer is supported by only a single axle.

   8. A combination vehicle according to any one of claims 1 to 7 wherein the rear of said first semi-trailer is supported by only a tandem axle set.
9. 9. A combination vehicle according to claim 1 wherein the rear of said second semi-trailer is supported by only a tandem axle set.
10. 10. A combination vehicle according to claim 9 wherein the tow coupling overhang at the rear of said second semi-trailer is no more than 1500mm.
11. 11. A combination vehicle according to claim 3 wherein the tow coupling overhang at the rear of said second semi-trailer is no more than 750mm.
12. 12. A combination vehicle according to claim 11 wherein the tow coupling overhang at the rear of said second semi-trailer is no more than 1100mm.
13. 13. A combination vehicle according to any one of claims 9 to 12 in which the length of its portion comprising the sum of said prime mover, said first semi-trailer
14. 14. A combination vehicle according to claim 13 in which the length of its portion comprising the sum of said prime mover, said first semi-trailer and said second semitrailer does not exceed 19 metres.
15. 15. A combination vehicle according to any one of claims 9 to 14 wherein the rear of said first semi-trailer is supported by only a tandem axle set.
16. 16. A combination vehicle according to any one of claims 9 to 14 wherein the rear of said first semi-trailer is supported by a tri-axle set.
17. 17. A combination vehicle according to claim 15 or 16 wherein said dolly frame is supported by a tandem axle set, the rear of said third semi-trailer is supported by a tri-axle set, and the total length of said combination vehicle does not exceed 36.5 metres.
18. 18. A combination vehicle according to any one of claims 1 to 15 wherein said dolly frame is supported by a tandem axle set, the rear of said third semi-trailer is supported by a tandem axle set, and the total length of said combination vehicle does not exceed 30 metres.
19. 19. A combination vehicle according to any one of claims 1 to 15 wherein said trailer is supported by an arrangement of exactly three axles, and the total length of said combination vehicle does not exceed 27.5 metres.
20. 20. A combination vehicle according to any one of claims 1 to 15 wherein said dolly frame is supported by a single axle set, the rear of said third semi-trailer is supported by a single axle set, and the total length of said combination vehicle does not exceed 26 metres.