AU2024201755A1

AU2024201755A1 - Heavy Vehicle Configuration

Info

Publication number: AU2024201755A1
Application number: AU2024201755A
Authority: AU
Inventors: Gary Byford
Original assignee: Byford Equipment Pty Ltd
Current assignee: Byford Equipment Pty Ltd
Priority date: 2014-02-28
Filing date: 2024-03-18
Publication date: 2024-05-02
Also published as: AU2021240194A1; AU2015227498B2; AU2017245467A1; AU2017245467B2; AU2018100199A4; AU2015227498A1; AU2021240194B2; AU2019240700B2; AU2019240700A1

Abstract

A large vehicle combination 1,100 including one or more tag trailers 16,116 each having a plurality of wheel sets 14,14',24'24',18,18' with trailer axles arranged in group sets, wherein the rearmost wheel set 18'of at least one group set is caster steered; and the spacing between adjacent in-line wheels in the same group set is greater than in traditional groups sets, the spacing of adjacent axles being between about 1.5m and about 2.5m, and the swept path of the vehicle during turning is less than 6m. Fig. 6 5/5 .......

Description

5/5

....... TITLE OF INVENTION

Heavy Vehicle Configuration

TECHNICAL FIELD

This invention concerns large combination vehicles (LCVs).

BACKGROUND

The following references to and descriptions of prior proposals or products are not intended to be, and are not to be construed as, statements or admissions of common general

knowledge in the art. In particular, the following prior art discussion does not relate to what is commonly or well known by the person skilled in the art, but assists in the understanding of the inventive step of the present invention of which the identification of pertinent prior

art proposals is but one part.

In Australia the maximum width of road vehicles is 2.5m and the maximum height is 4.3m. Vehicles may exceed these limits but are restricted to selected road routes having a general classification.

The most popular configurations of trailer combinations have a prime mover with dual drive

axles, with three axles on each trailer and four tires on each axle. In lighter duty combinations the trailer may have only two (tandem) axles or may have a single, normally wide track wheel on each end of each axle.

In trailer design it is usual to limit the load carried to 9 tonnes per axle. When the trailer has tandem axles, the pair in practice can only support 17 tonnes. This would normally be

overcome by using a triple axle configuration but this in turn introduces other disadvantages.

Bulk liquid tankers face special design requirements in that the steering characteristics change moving from full to empty. If the trailer is being used for milk collection from farm to milk processing centres, the farm access road may not be ideal for a long vehicle. The

vehicle's turning circle may be too large for some collection areas having regard to the layout of farm buildings and other obstacles. If the vehicle combination has to travel over grassy areas these may become muddy in wet weather and the prime mover may lose traction.

Reducing the length of the vehicle to reduce turning circle tends to proportionally reduce load capacity. This affects the economics of the collection operation. B-doubles are limited

to a length of 26m if they are fitted with front underrun protection devices and have a maximum weight limit. Milk tankers must be able to travel in all parts of the territory in which they collect on behalf of a business. In turning, such vehicle combinations commonly have a turning circle of about 15m and a swept path of at least 8m. The swept path is the distance between where the outside front tyre tracks and the innermost trailer tracks. The swept path is a critical measure of the manoeuvrability of a LCV.

An object of the present invention is to ameliorate the aforementioned disadvantages of the prior art or to at least provide a useful alternative thereto.

SUMMARY OF INVENTION

The invention according to one or more aspects is as defined in the independent claims.

Some optional and/or preferred features of the invention are defined in the dependent claims.

Accordingly, in one aspect the invention provides:

A large vehicle combination including:

one or more tag trailers each having a plurality of wheel sets with trailer axles arranged in group sets;

wherein :

the rearmost wheel set of at least one group set are steered; and

the spacing between adjacent in-line wheels in the same group set is greater than in traditional groups sets, the spacing of adjacent axles being between about 1.5m and about 2.5m.

The steering of the rear set of wheels may be achieved by a variety of configurations, including self-tracking or steerable axles, individually steered wheels or other mechanisms whereby the wheels track in response to the direction of travel of a lead towing vehicle. The steerability of the rear-mostwheels greatly reduces wear on the tyres, enabling an extension of the life of the tyres of the rear steerable wheels by a factor of over 3 times, reducing lateral or horizontal drag across road and ground surfaces thereby avoiding damaging wear and tear on roads and ground surfaces.

Another advantage of providing steerable rearmost wheel sets is the reduction in the ring feeder pin and king pin loads during turning. Structural fatigue and wear on component parts of the vehicle are substantially reduced. For example, a king pin load that would normally be 2500kg in a non-steered trailer combination may be reduced by a factor of 2 - 3, down to about 900kg.

The positioning of the ring feeder is preferably immediately behind the first trailer's end to minimise the distance between the end of the first trailer and the tag trailer's dolly or

forecarriage, whilst providing sufficient clearance for turning. Preferably the ring feeder coupling is located within 300mm - 600mm of the rear of the first trailer.

The swept path of the vehicle is preferably less than about 6m, preferably less than 5.8m, and most preferably 5.7m. Such a small swept path is achieved under the invention by the combination of the spacing of the larger spacing of the wheel axles and the provision of at least one steerable wheel set in the group set. However, the length of the vehicle also is a contributing factor. A standard 25m B Double swept path is about 8.5m, whereas a 26m A

Double fitted with wheel group sets according to the invention has a swept path of about 6.33m. A standard 19m B Double has a swept path of about 6.7m, whereas a 20m A-B Double fitted with wheel group sets according to the invention has a swept path of about 5.8m. A standard 30,000 long tri-axle single vehicle has a swept path of about 6.7m,

whereas a 26m A Double single lead trailer fitted with wheel group sets according to the invention has a swept path of about 5.7m.

By providing a steerable final wheel set on each tag trailer, the tag trailer is able to pivot about a vertical axis corresponding to the wheel set immediately in front of the trailing steerable wheel set and the steerable wheel set generally turns onto the direction of the path that the lead vehicle is following.

Preferably the group sets comprise a pair of axles in tandem. Preferably the sets of wheels have pairs of wheels, one wheel on each end of the axle, so that only one steerable

wheel set is required for each group set. However, group sets may comprise triple axle group sets.

The vehicle combination may have a front trailer and a rear trailer. The rear of the front trailer may have a tandem group, the rear trailer may have a leading tandem group and a

trailing tandem group. The leading tandem group of the rear trailer may support a fifth wheel set of the rear trailer. A fifth wheel coupling describes a trailer hitch support structure comprising a substantially horizontal wheel commonly located on the tail end of a prime mover or dolly.

Although counter-intuitive, the spacing of the wheel sets in the tandem (or triple) group is preferably greater than is customary. This greater spacing was thought to be undesirable

because of the trade off with regard to vertical load capacity for the relevant group set supporting a vertical loading. However, with regard to this invention, the spacing from axle axis to axle axis of adjacent axles in the tandem or tri-group set is advantageously in the range 1.5-2.5m. The spacing between adjacent axles in each of the tandem groups may be adjusted so that the load is better distributed and the total load limit or capacity of the

vehicle is maximised. The spacing allows each axle set to be categorised as an independent or separate axle set that can be rated to carry a 10T load, compared to the smaller load ratings per axle set of about 7T for tandem and triple axle groups. This greatly increases the total load able to be carried by a LCV. For example, a 20m B Double made according to the

invention with axles in the same group widely spaced by about 1500 - 2500mm, preferably about 1800 - 2200mm, and most preferably about 2200mm, is designed to carry 63.5T, compared to the equivalent prior art vehicle (a 19m B Double) having a load capacity of 57.5T. Another example is a 26m B Double made according to the invention that has a prime mover with a typical load carrying capacity of 23.5T, but due to the wide spacing of the axles sets within groups of about 1.5 - 2.5m, preferably about 1800 - 2200mm, and most

preferably about 1900mm, the first trailer and tag trailer, being supported by 6 wheel sets each rated as a single and independent axle set and engineered to carry a load of up to 10T, results in a significantly larger load capacity of over 70T, preferably 75T, most preferably over80Tand specifically 83.5T, orwhere single axles are rated to carry upto 9T, a maximum capacity of 77.5T for a LCV that is between 25 - 26m in length.

In a preferred arrangement the vehicle combination has a three axle prime mover with a

fifth wheel and connected to this fifth wheel is the lead tanker, via its king pin. This trailer is supported at its rear by two axles, spaced widely apart (between 1.5m and 2.5m) to improve the performance of the steer axle that the rear axle possesses. A tandem dolly is connected to the rear of the lead trailer via a ring feeder, and may or may not have a steer axle at its rear. The dolly supports a fifth wheel and connected to this fifth wheel is the king pin of the tag trailer. The tag trailer is also supported by tandem axles at its rear (the tag

trailer axles spaced from one another by between 1.5m and 2.2m), with the rearmost axle being self-steering. The king pins and fifth wheels are located in positions to optimize weight distribution.

The tandem axles of both trailers may be 1900-2100mm apart.

The tandem axles of the dolly may be 1400-1600mm apart.

The rear axle of the front trailer and the front of the dolly frame may be 3300-3800mm apart. The distance between the rear tow point of the first trailer to the centre of the fifth wheel supported by a dolly for the shorter (20m vehicle) in the form of a forecarriage is 3000-4500mm. The rear tow point may be a commercially available RINGFEDER© coupling.

The rear axle of each trailer pair may be self-steering. Self-steering for the rear axle of the dolly pair is optional, but preferable and steerage of this wheel set mitigates against

unwanted horizontal forces when the vehicle is turning.

The self-steered wheels preferably have castor action.

The vehicle combination according to one embodiment provides a prime mover with a fifth wheel, a front tanker trailer with a pin for coupling to the fifth wheel of the prime mover

and tandem axles at the trailer rear, a rear tanker trailer with a pin for coupling to a fifth wheel and tandem axles at the trailer rear, and a dolly with a frame for supporting said fifth wheel, a draw bar for mutually connecting the two trailers, the dolly frame being supported by tandem axles, wherein if the mutual spacing of the tandem axles is x, the separation between the rear driven wheel of the prime mover and the tandem axle of the front trailer and the separation between the rear dolly axle and the tandem axle of the second trailer is about 2.5x. The extent of variation may be±5%.

The dolly aspect of the invention provides a dolly for joining a rear trailer to a front trailer comprising a frame for supporting a fifth wheel, an A-configuration draw bar extending forwardly of the frame, a pair of wheel axles and wheel assemblies rendering the frame mobile, wherein the wheels of the trailing axle are self-steering.

The trailer aspect of the invention provides a trailer with a locating pin for a fifth wheel coupling at the front end and a pair of axles at the rear end, wherein the leading axle has

wheels and the trailing axle has self-steered wheels.

Advantageous Effects of Invention

1. The purpose of this arrangement is to share the load more evenly by spacing the axles differently, which is kinder to roads and bridges. The combination can carry three lots of the capacity of two axles, instead of two lots of the capacity of three axles. Therefore, as

the load is better distributed, the limit on the mass is increased. Currently in Victoria, the higher mass limit (HIML) of three axles is 21T (7.5T per axle), and the HML of two axles is 17T (8.5T per axle). This means by using tandem axles, all of the axles in the configuration can carry an extra tonne each. Moreover, advantageously according to the invention, where axle sets in a group set are spaced between 1.5 - 2.5m apart, they still can function as a group set, but are rated as independent or single axles with a load carrying capacity of 10T each.

In a 20m B Double made according to the invention, the prime mover steering set of wheels can carry 6.5T, the prime mover tandem axles can carry 17T, and the 4 separate single axles supporting the trailers (see Fig. 4) can each support 10T, for a vehicle total of 63.5T. Substantial elimination of sideways drag from trailing tandem pairs of wheel sets and

substantial increase in load capacity of the vehicle are achieved by this new configuration.

2. The self-steering axles used in this invention also decrease the swept path of the

combination. By having the self-steer axles, the swept path can be less than that of a 19m

B-double. The self-steer axles are also designed to lock up at higher speed, so that they act as a rigid axle which improves the stability at said higher speeds.

3. The self-steering axles will reduce the tyre scrub caused by horizontal tracking when cornering, which in turn reduces the tyre wear. This in turn means less friction, less fuel

consumption and lower emissions.

In another aspect there is provided a longer vehicle combination for road transport of bulk goods comprising a prime mover, a front trailer and a rear trailer, wherein the trailer axles are arranged in three tandem sets, the rear of the front trailer has a tandem set, the rear trailer has a leading tandem set and a trailing tandem set and the leading tandem set of the rear trailer is part of a dolly which supports a fifth wheel of the rear trailer.

The spacing of the tandem sets may be 1.5-2.5m, preferably 1900-2100mm. The rear axle of the tandem sets preferably has a pair of self-steered wheels which have a caster action

as herein defined. The endmost axle of the combination is preferably devoid of caster action. The prime mover may have three axles with a fifth wheel and connected to the fifth

wheel may be the front trailer. A tandem dolly may be connected to the rear of the front trailer by a coupling and may have a rear axle with self- steered wheels. The dolly may support a fifth wheel and a tag trailer may be connected to the fifth wheel. The tandem

axles of the dolly are preferably 1400-1600mm apart. The tandem axles of both trailers are preferably 1900-2100mm apart. The distance between the tow point of the first trailer to the centre of the fifth wheel supported by the dolly is preferably 3000-4500mm, preferably about 3030mm, and most preferably 3035mm.

In still another aspect of the invention, there is provided a longer vehicle configuration for the road transport of bulkgoods comprising a prime moverwith a fifth wheel, a front tanker

trailer with a pin for coupling to the fifth wheel of the prime mover and tandem axles at the trailer rear, a rear tanker trailer with a pin for coupling to a fifth wheel and tandem axles at the trailer rear, and a dolly with a frame for supporting said fifth wheel, a draw bar for mutually connecting the two trailers, the dolly frame being supported by tandem axles, wherein if the separation between the rear drive wheel of the prime mover and the tandem axle of the front trailer is x, the separation between the rearmost wheel of the second trailer and the rearmost wheel of the first trailer is about 2.5x. The extent of the variation of the separation is preferably ±5%.

In still another aspect of the invention, there is provided a dollyforjoining a rear trailerto a front trailer in a longer vehicle combination for the road transport of bulk goods comprising

a frame for supporting a fifth wheel, an A-configuration draw bar extending forwardly of the frame, a pair of wheel axles and wheel assemblies rendering the frame mobile, wherein the wheels of the trailing axle are self-steering.

Broadly stated, the large vehicle combination may include:

one or more tag trailers each having a plurality of wheel sets with trailer axles arranged in group sets,

wherein :

the rearmost wheel set of at least one group set are steered; and

The steering of the rear set of wheels may be in the form of caster steered wheels.

The vehicle may be an A- or A-B- Double vehicle and the horizontal load on the king pin

coupling the lead trailer to the prime mover of the A- or A-B- Double vehicle may be less than 1000kg during a 180 degree turn on a normal dry road surface.

The swept path of the vehicle may be less than about 6m.

BRIEF DESCRIPTION OF DRAWINGS

The invention may be better understood from the following non-limiting description of preferred embodiments, in which:

Figure l is a side view of a 26m A Double vehicle combination according to one aspect of the invention;

Figure 2a is a schematic side view of a prior art 25m B Double;

Figure 2b is a schematic side view of a prior art 19m B Double;

Figure 3 is a schematic side view of the 26m A Double shown in Fig. 1;

Figure 4 is a schematic side view of a 20m A-B Double vehicle combination according to another aspect of the invention;

Figure 5 is a comparative grave representation of the respective king pin loadings of various vehicle combinations according to the prior art and embodiments of the invention; and

Figure 6 is a side elevation of a dolly hitch arrangement of the embodiment shown in Fig. 1.

DESCRIPTION OF EMBODIMENTS

Referring now to the drawings, in Fig. 2a a conventional vehicle 30 made according to the prior art is shown having trailers 12,16 with supported by trailing group triplet wheel sets

40,80 that are fixed and non-steerable. Such wheel sets 40,80 operate well when the vehicle 2 is travelling in a relatively straight direction. However, the very nature of LCVs is that they are often required to be driven into tight spots with limited room for turning. In such situations, the middle set of wheels 46 in the wheel group set 40, tend to turn with little

sideways force as they are located close to the pivot point 20 of the tag trailer 16 mount. However, the front 42 and rear 44 wheel sets tend to drag sideways, causing road or ground infrastructure damage, and a high rate of tyre wear.

In Fig. 2, there is shown a 19m B Double 30a having a prime mover with a typical front set of steerable wheels rated to support 6.5T and a trailing tandem group set rated to bear a load of 17T. The front trailer is supported bya forecarriage 21a that has, at its rear, a tandem

set of non-steerable wheels 40a, as does the rear tag trailer with the tandem set of wheels 80a, each tandem wheel set having a load supporting capacity of 17T. The total load bearing capacity of the vehicle 30a is therefore: 6.5 + 3 x 17T = 57.5T compared to 63.5T for the inventive equivalent vehicle 100 shown in Fig. 4 as described below.

A vehicle 1 having a prime mover 2 is shown in Figs. 1 and 3, which vehicle 1 has steered

wheels 4 beneath cab 6 and a pair of driver axles 8, 8' in conventional manner. A fifth wheel assembly 10 between the driver axles supports the forward end of a front trailer 12, 8560mm in length. The trailer 12 has tandem axles 14, 14' at its rear having an unusually large spacing of 1924mm. The latter spacing is economical and improves load distribution, reduces the horizontal forces to which the non-steered wheels might be subjected. The distance between axle 8' and axle 14 is 5053mm. Front trailer 12 articulates about the axis of the fifth wheel 10.

Rear trailer 16 is likewise 8560mm in length and has a tandem axle assembly 18, 18'. Again, the spacing between the trailer axles is 1924mm. The forward end of the rear trailer is supported by a fifth wheel 20 borne by dolly frame 22. The tandem axles 24,24' of the dolly frame are 1500mm apart. The dolly frame 22 has an A-frame draw bar 26 which hitches to the rear of front trailer 12 via a RINGFEDER© coupling. The distance from the king pin 25 at the rear of trailer 12 supporting the A-frame 26 to the front of the dollyframe 22 is 3614mm, which allows the dolly to articulate.

The fifth wheel 20 allows the trailer 16 to articulate. The combined effect of three axes of articulation is to reduce the turning circle to 21m diameter instead of the 23780mm which is the distance separating steered axle 4 and the rearmost axle 18'. The improved weight distribution of three tandem axle sets 14,18,24 over the prior art twin triplet combination

enables the General Mass Limit (GML) to be up to 68.5TN and the Higher Mass Limit (HML) to be up to 74.5TN. In particular, the spaced apart wheel sets 8,8'; 24,24'; and 18,18', each individually have a load rating of 10T, (currently 9T in the State of Victoria, Australia, but engineered to support 10T), so that the total load carrying capacity for vehicle 1 is 6.5 + 17 + 6 x 10T = 83.5T, compared to the equivalent prior art 25m B Double vehicle 30 represented in Fig. 2a of 6.5 + 17 (for the prime mover 6) + 21+ 21T (21T for each of the tri-group sets

40,80) = 65.5T. This represents a significant load carrying advantage for the inventive vehicle 1 over its prior art equivalent vehicle 30.

The wheel axles of the wheel sets 14,14',18,18'24,24' are connected to the two trailer chassis 12,16 and to the dolly frame 22 by trailing arm suspension units incorporating air

bags.

Conventional retractable legs may be provided to extend from the underside of both trailer chassis.

The axles of wheel sets 14', 24' and 18' are fitted with self-steered wheels which have a caster action whereby to trail the direction generallydetermined by the prime mover 6. This is effected by the use of truncated cone mounts 15for the wheels with each wheel set joined by a horizontal tie rod 17'. Caster action only occurs in wheel sets 14', 24' and 18' at speeds of up to 40kph in order to confine this assistance to steering to the part of the vehicle journey requiring turns at slow speeds. At cruising speed (above 40kmph) the wheel sets 14',18,24' are locked and there is no caster action. The speed at which the axles of the wheel sets 14',18',24' are locked and unlocked is programmed by an electronic braking system (EBS) provided with the trailer 12,16.

Another version of the vehicle combination of the invention is shown in Fig. 4 in the form of a 20m A-B Double 100 having a prime mover 106, hauling a first trailer 112 and a tag trailer

116. The first trailer is supported at its front end by a fifth wheel coupling 110 and a single fixed wheel set 114 at its rear end. The tag trailer 116 trails the rear end of the first trailer 112 by a ring feeder coupling 125. A forecarriage frame 122 supports the front end of the tag trailer 116 and is drawn by an A-frame drawbar 126 in a manner similar to the A-frame

drawbar 26 of the embodiment shown in Figs. 1 and 3. The front end of the tag trailer 116 is mounted on the forecarriage 122 for articulation by a fifth wheel coupling 120. The forecarriage 122 is supported by a wheel group set of widely spaced front 124 and rear 124' wheel sets in a manner similar to the wheel sets 24,24' shown in Figs. 1 and 3, their spacing being of the order of about 2.2m so that the wheel sets 124,124' are rated as single axles with an engineered load capacity of 10T. The trailing wheel set 124' in steerable at low speeds (less than 40kmph) to effectively mitigate sideways forces to which non-steerable

wheels would be subjected when a vehicle made according to the prior art, such as a vehicle 30 shown in Fig. 2, is turning. In the present embodiment 100, the front pair of wheels 124 follow the lead of the first trailer with limited sideways drag and the trailing wheel set 124' is steered by a caster action so that there is little or no sideways drag by the trailing pair of

wheels 124'. The rearmost wheel set 118 is fixed and trails effectively without steering.

The vehicle 100 advantageously comprises 4 wheel sets 114,124,124',118 on the trailers 112,116, that are well spaced (the distance between the paired wheel sets 124,124' on which the dolly 122 is mounted being between about 1.9 - 2.0m) to better distribute the load. This wide base support and more dispersed distribution of load support is achievable by providing a steerable wheel set 124'.

With reference to Fig. 5, a modelling graph of a king pin 10,110 load of various LCV combinations is shown, including that for vehicles 1,30,100 as they travel through a 180

turn. A like for like comparative study may be made between prior art vehicle 30 and the preferred embodiment vehicle 1 which haul similar massed loads of about 60T. It can be seen that, at the high load mid-point of the turn (around 30 - 40 seconds into a turn that takes about 40 - 50 seconds to complete), the king pin 10 load of the prior art vehicle 30 is about 3 times the loading on the king pin 10 of the preferred comparable vehicle 1, despite hauling similar loads. Accordingly, this demonstrates the large advantage of the preferred

wider spacing of the wheel sets within each group set to permit improved load distribution and the steerability of the trailing wheel sets 14',24',18' have a direct effect on reducing the load applied to the king pin 10 when the vehicle1 is turning. Accordingly, a A_B or A Double vehicle 1,100 is provided that subjects the king pin coupling 10,110 to a maximum load on a

flat standard road surface of less than 1000kg.

In Fig. 6, the ring feeder arrangement 25 of the 26m B Double vehicle 1 is showing in greater detail. The position of the ring feeder 25 and particularly the vertical axle hitch point 27 is mounted to the front trailer 12 as far forward as possible towards the centre C of the axle group 14,14' to greatly improve the dynamics of the dolly 22 connected to the

ring feeder 25. The ring feeder coupling 25 is located within 300mm - 600mm (when considered in plan view) of the rear axle of wheel set 14' of the first trailer12, preferably

about 500mm in distance, and most specifically in the embodiment shown, within about 520mm. The wheel sets 14,14', axle to axle, are advantageously spaced between 1700 2200mm of each other, preferably 1900 - 2000mm, and most specifically, about 1920mm of each other, so that the pair of wheel sets 14,14' operate ostensibly as separate, single

axles.

It is to be understood that various modifications of and/or additions to the invention can be made without departing from the basic nature of the invention. These modifications and/or additions are therefore considered to fall within the scope of the invention.

Throughout the specification and claims the word "comprise" and its derivatives are intended to have an inclusive rather than exclusive meaning unless the contrary is expressly

stated or the context requires otherwise. That is, the word "comprise" and its derivatives will be taken to indicate the inclusion of not only the listed components, steps or features

that it directly references, but also other components, steps or features not specifically listed, unless the contrary is expressly stated or the context requires otherwise.

In the present specification, terms such as "apparatus", "means", "device" and "member" may refer to singular or plural items and are terms intended to refer to a set of properties, functions or characteristics performed by one or more items or components having one or more parts. It is envisaged that where an "apparatus", "means", "device" or "member" or

similar term is described as being a unitary object, then a functionally equivalent object having multiple components is considered to fall within the scope of the term, and similarly, where an "apparatus", "assembly", "means", "device" or "member" is described as having multiple components, a functionally equivalent but unitary object is also considered to fall within the scope of the term, unless the contrary is expressly stated or the context requires

otherwise.

Orientational terms used in the specification and claims such as vertical, horizontal, top, bottom, upper and lower are to be interpreted as relational and are based on the premise that the component, item, article, apparatus, device or instrument will usually be considered in a particular orientation, typically with the wheels 14,14', etc. lowermost.

Claims

The Claims Defining the Invention are as Follows:

1. A large vehicle combination 1 including:

a prime mover 2 with a steered axle 4, a front trailer 12 having a trailing tandem wheel set 14,14' with trailer axles also arranged in group sets; and a rear trailer 16 having a trailing tandem wheel set 18,18'; and

three axes of articulation 10,25,20 in the form of a fifth wheel mount 10 for the front trailer 12, a king pin 25 coupling a dolly 22 to the front trailer 12 and a second fifth wheel mount 20 coupling the rear trailer 16 to the dolly 22,

a rearmost axle 14,18 of each of the trailing tandem wheel sets 14,14',18,18' of the front and rear trailers 12,16 being self-steered;

the rear trailer tandem axles being spaced from one another by between 1.5m and 2.2m; and

the combined effect of having three axes of articulation 10,25,20 is that the turning circle of the large vehicle combination 1 is less than the distance separating a steered axle 4 of the prime mover 2 and the rearmost axle 18' of the rear trailer 16.

2. A large vehicle combination according to Claim 1, wherein the vehicle's 1General Mass Limit (GML) is up to 68.5TN and the Higher Mass Limit (HML) is up to 74.5TN.

3. A large vehicle combination according to Claim 1or 2, wherein the vehicle 1 is an A double and the prime mover 1 includes 3 sets of wheel sets in which the wheels within each wheel set are spaced apart relative to each other, including:

(a) the trailing tandem wheel set 14,14' of the front trailer 12;

(b) the dolly wheel sets 24,24'of the dolly 22; and

(c) the trailing tandem wheel set 18,18',

wherein each of the 3 wheel sets individually have a load rating of 10T.

4. A large vehicle combination according to Claim 3, wherein the total load carrying capacity for the vehicle 1 is (6.5 + 17) + (6 x 10)T = 83.5T.

A large vehicle combination according to Claim 3 or 4, wherein the wheel axles of the wheel sets 14,14',18,18'24,24' are connected to the two trailer chassis 12,16 and to the dolly frame 22 by trailing arm suspension units incorporating air bags.

6. A large vehicle combination according to any one of Claims 3 to 5, wherein the axles of the front, dolly and rear trailing wheel sets 14', 24' and 18' are fitted with self-steered wheels which have a caster action whereby to trail the direction generally determined by the prime mover 6.

7. A large vehicle combination according to Claim 6, wherein the caster action is effected by the use of truncated cone mounts 15 for the wheels with each wheel set joined by a horizontal tie rod 17'.

18'

18

24'

20

24 22 16

26 FIGURE 1

25 14'

1

14

2 8 8'

10

12

4

80 84

16 86

80a 82

40 44

20 46

40a 42 FIG. 2a (Prior Art)

FIG. 2b (Prior Art)

21a

10

the 8 23 8a 8 12

o o

4 6 30a

18'

18 118

116

20 24' 124

120

24 122 124

22 (20m A-B Double) (26m A Double)

26 126

FIG.3 FIG.4

25 125

15 & 14 17 14 114

112 10

'8'

110 12

8 o o 106

4 6 100