AU2017203316A1 - An Improved Arrangement for an Articulated Vehicle, such as for a Trailer of a B-Double or B-Triple Vehicle - Google Patents

Abstract

The present invention provides a towing vehicle (14) which includes an elongate frame structure (28) with leading and trailing ends and which is mounted on a multi axle wheel system (32). From adjacent or near the leading end and extending over a major part of the frame structure (28) towards the trailing end, the frame structure (28) defines a cargo support surface (30). Between the trailing ends of the frame structure (28) and the cargo support surface (30), the frame structure (28) carries a connector device (38) able to be coupled to a mating connector device at a leading end of a tag semi-trailer (16) so the towing vehicle (14) is able to draw the tag trailer (16) and to pivot relative to the tag trailer (16). The multi-axle wheel system (32) includes a set of two or three non-steering axles (34, 35) spaced along the frame structure (28) and, between the set of non-steering axles (34, 35) and the rear end of the frame structure (28), one steering axle or a set of two steering axles (36). The multi-axle wheel system (32) enables travel of the towing vehicle (14) and is located to the trailing end of the frame structure (28), with the one steering axle or at least a rearmost one of the two steering axles (34) between the trailing ends of the support surface (30) and the frame structure (28). 65 16 15 14 26 1I-- -)-- g L- 22 78 86 85 84 28 24 20 Figure 1 0 03 6 a0 3 5 0 03 4 Figure 2

Description

AN IMPROVED ARRANGEMENT FOR AN ARTICULATED VEHICLE, SUCH AS FOR A TRAILER OF A B-DOUBLE OR B-TRIPLE VEHICLE

CROSS-REFERENCE

[0001 ] This application claims benefit of and priority to, Australian Provisional Patent Application No.: 2016902766, filed on 14 July 2016, the disclosure of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

[0002] The present invention relates to an improved arrangement for an articulated vehicle. The arrangement is suitable for a trailer for use as the lead trailer of a B-double vehicle, or as the first and/or second trailer of a B-triple vehicle, however it should be appreciated that the present invention is not limited to those uses only. For example, the arrangement may also be used for an articulated vehicle comprising a rigid body truck to which a semitrailer is coupled by a turntable at the trailing end of the body of the truck. In each case, the invention relates to an arrangement which improves the cornering performance, in terms of swept path maximum, of an articulated vehicle.

BACKGROUND ART

[0003] Any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the invention. It should not be taken as an admission that any of the material forms a part of the prior art base or the common general knowledge in the relevant art in Australia or elsewhere, on or before the priority date of the disclosure herein.

[0004] Articulated vehicles of the general type mentioned above, in particular B-double and B-triple vehicles, are used extensively for road transportation of heavy and oversized loads. They can be difficult, or dangerous, to manoeuvre on public road systems while this, and their size, has resulted in such vehicles being restricted to use on individually approved networks of the road system. As a response to this restriction, there have been numerous proposals for improving manoeuvrability, generally by adoption of arrangements using steerable axles. Examples of such proposals are provided by the patent specification W02002/044005 of Trackaxle Pty Ltd and that company’s subsequent patent specification W02006/010227; patent specification AU2009101262 of Russell Barry; patent specification AU2013203929 of Raleigh Corporation Pty Ltd; and patent specification US2015/283934 of Scheuerle Fahrzeugfabrik GmbH.

[0005] The earlier proposal of Trackaxle Pty Ltd in W02002/044005 provides a trailer having a chassis connectable at its forward end to a wheeled section of a lead vehicle, for relative pivoting on a first upright axis, with the rear end of the chassis supported on a sub-chassis that has a plurality of pairs of wheels and that is able to pivot relative to the chassis on a second upright axis, with each pair of wheels provided on a respective rigid axle that is pivotally mounted on the subchassis. An adjustable stop limits the angle of free pivoting of the sub-chassis on the second axis, and steering means responsive to that free pivoting for steering at least two pairs of wheels oppositely to an adjacent pair of wheels. The later Trackaxle Pty Ltd proposal of W02006/010227 relates to a command steer assembly for an arrangement such as in accordance with their earlier proposal (W02002/044005).

[0006] The Russell Barry proposal of AU2009101262 relates to a heavy load trailer that, in order to improve manoeuvrability, has a front steerable axle, a rear steerable axle, a non-steerable axle set between the front and rear steerable axles, and a frame (or chassis) supported by the front and rear steerable axles and by the non-steerable axle set. The arrangement is said to cause the tyres of the non-steerable axle set to seek a straight path during forward travel that is less subject to turning forces induced by the front and rear steerable axles, improving stability and manoeuvrable operation.

[0007] In AU2013203929, Raleigh Corporation Pty Ltd puts forward a load sharing walking beam trailer member for use with a tow vehicle having a trailer hitch.

The load sharing walking beam trailer member, at its forward end, has a hitch connector, such as a fifth wheel coupling device, for a connection to the tow vehicle hitch to enable pivoting on a first upright axis. At its rear end, the load-sharing member has a wheel assembly with at least one axle with a pair of spaced wheels on a wheel mounting structure that is rotatable on a second upright axis. Intermediate of its ends, the load sharing member has a connector device at which a load carrying trailer is connectable to enable relative pivoting on a generally horizontal transverse axis defined by the connector device.

[0008] US2015/283934 of Scheuerle Fahrzeugfabrik GmbH suggests a complex tractor and a trailer combination suited for transporting a specific elongate load, such as a wind turbine rotor blade. The trailer has a telescopic load support deck that has a goosed neck at the forward end by which it is supported on the tractor for relative pivoting on an upright axis, and that otherwise supported at the rear end on a multi-axle chassis. The chassis is rotatable relative to the support deck on an upright axis, while the forward axle of the chassis is hydraulically steerable.

[0009] The arrangements of such prior art proposals provide benefits in terms of manoeuvrability and load carrying capability. However, they either are not suited for use in relation to B-double or B-triple vehicles, or involve excessive complexity and cost. The present invention seeks to provide an arrangement preferably suited for use in B-double and B-triple vehicles, which enables improved manoeuvrability. At least in preferred forms, the invention is directed to enabling development of such vehicles that, for a given length, comply with more stringent performance-based standards than current vehicles of that length in that the vehicles have a reduced maximum width of a swept path in a prescribed 90° low speed turn and thereby enable approval for operation on a greater range of approved networks of the public road system.

DISCLOSURE OF THE INVENTION

[0010] According to one aspect of the present invention there is provided a towing vehicle for use as part of an articulated vehicle, and suitable for use as the lead trailer of a B-double vehicle, or as the first and/or second trailer of a B-triple vehicle, or as a rigid body truck for towing a semi-trailer. The towing vehicle includes an elongate frame structure that has a leading end and a trailing end and that is mounted on a multi-axle wheel system. From adjacent or near to the leading end and extending over a major part of the length of the frame structure towards the trailing end, the frame structure defines a cargo support surface. Between the trailing end of the frame structure and a trailing end of the cargo support surface, the frame structure carries a connector device, such as a turntable, by which the towing vehicle can be coupled to a mating connector device, such as a depending king pin, at a leading end of a tag semi-trailer whereby the towing vehicle is able to draw the tag trailer and to pivot about an upstanding axis relative to the tag trailer. The multi-axle wheel system has at least three wheeled axles, including a set of two or three non-steering axles spaced along the frame structure and, spaced between the set of non-steering axles and the rear end of the frame structure, one steering axle or a set of two steering axles. The multi-axle wheel system enables travel of the towing vehicle and is located at or adjacent to the trailing end of the frame structure, such as with the one steering axle or at least a rearmost one of the two steering axles located between the trailing ends of the cargo support surface and the frame structure.

[0011] In a first arrangement, the towing vehicle comprises a semi-trailer for a B-double or a B-triple vehicle, the towing vehicle may have a connector device, such as a depending king pin, spaced from the forward end of the frame structure by which the trailer can be coupled to a mating connector device, such as a turntable, at a trailing end of a tractor tow vehicle whereby the trailer is able to be drawn by the tractor vehicle and to pivot about an upstanding axis relative to the tractor vehicle. In that first arrangement, the multi-axle wheel system typically comprises the sole wheel support for the frame structure.

[0012] In a second arrangement, the towing vehicle comprises a rigid body truck. Thus, in that second arrangement, the towing vehicle has, at the forward end of the support frame, a driver’s cabin housing a drive motor and at least front steering wheels, with a transmission operable between the motor and a driven axle of the set of non-steering axles.

[0013] In the first arrangement, in which the towing vehicle comprises a semitrailer, the towing vehicle may have a variety of form, including: (i) an enclosed, curtain sided trailer body style, such as in any of the main configurations of flat, single drop and double drop deck forms for the cargo support surface; (ii) a solid side wall enclosed body style for a refrigerated/freezer vehicle; (iii) a solid side wall enclosed body style for an ambient temperature pantechnicon; (iv) an open trailer with a typically flat deck, with forward and rearward racks and various deck configurations; (v) an open, chassis only skeletal deck or “skel”, such as for temporarily affixing shipping containers and the like; (vi) a bulk carrying body style or a tipping bulk carrying body style, such as for carrying sand, dirt, gravel or other bulk commodities; and, (vii) a fluid carrying body style, such as a tanker for carrying liquids or gas.

[0014] In each of the first and second arrangements, an important aspect of the towing vehicle resides in the multi-axle wheel system. As indicated, this can have a set of two or three non-steering axles and, rearward of that axle set, one or two steering axles. The, or each, steering axle may be, and preferably is, self steering. However the, or each, steering axle can be steerable, if required, under the action of a control mechanism, such as a mechanism that is hydraulically, pneumatically or electrically operable. In each case, the steering axle is controlled by a hydraulic, pneumatic or electrically operable locking mechanism by which the, or each, steering axle is able to be held against steering above a nominal speed, such as from 30 to 40 kilometres per hour. As a consequence, steering by the, or each, steering axle is permitted only during low speed travel, such as when required for tight turns, such as encountered in built up areas. At higher speeds at which the, or each, steering axle is locked, the steering axle performs in the same way as a non-steering axle.

[0015] The multi-axle system is able to overcome the cornering performance restrictions applicable to longer B-doubles greater than 26 metres in overall length, as well as providing similar benefits in other vehicle combinations to which the invention is applicable. In addition to the multi-axle system having both non-steering and steering axles, it also may have spacings between axles that depart from common industry arrangements for non-steering sets and also for axle sets that, as a whole, enable steering. In a three axle multi-axle system as required by some embodiments of the present invention, the centre-to-centre distance between the two non-steering axles may be in the range of from about 1,450mm to about 1,700mm, such as from about 1,475mm to about 1,675mm, and preferably about 1,500mm, 1,600mm or 1,650mm depending on the selected form of towing vehicle, compared with common industry spacing of from 1,200mm to 1,380mm. This minimises tyre “scrub”. Additionally, the centre-to-centre spacing between the rearmost non-steering axle and the steering axle, with the steering axle positioned for non-steering travel, being even greater at from about 1,750mm to about 2,065mm, such as from about 1,775mm to about 2,040mm, and preferably about 1,800mm or 2,015mm depending on the selected form of towing vehicle. Thus, the multi-axle system may be characterised by an uneven axle spread.

[0016] With a multi-axle system having three non-steering axles, the distance between centres may be less than with two non-steering axles, such as by about 30mm to 60mm. Similarly, with a multi-axle system having a set of two steering axles, the centre-to-centre spacing between these axles may be similar to that between non-steering axles, but with the spacing between the rearmost nonsteering axle and the nearer steering axle still most preferably providing an uneven spread between the non-steering and steering axle sets.

[0017] The combination of factors of the towing vehicle of the present invention and a tag trailer, such as in a B-double, allows the steering wheelbase (also known as the “S-dimension” or rear suspension centre) to be shorter than a trailer having its connector device for coupling to a connector device of a tractor vehicle and with a multi-axle wheel system having all axles non-steerable and a uniform spread between centres. The combination of factors also increases the “moment arm” (distance) from the multi-axle system steer centre to the connector device for coupling to the connector device of the tag trailer.

[0018] The towing vehicle of at least preferred forms of the invention has enhanced cornering performance measured as swept path maximum. The improvement is such that the cornering performance of a 30 metre 9-axle B-double having the towing vehicle of the present invention as the lead trailer is able to be comparable with that of a current standard 9 axle B-double up to four metres shorter. Thus, the towing vehicle of the present invention is such that the 30 metre B-double potentially can gain almost unrestricted access to the current 26 metre B-double network of the road system, whereas a conventional 30 metre B-double can gain restricted access to small portions of the road system.

[0019] A 30 metre B-double having a towing vehicle of the present invention as the lead trailer could, for most body styles or configurations listed above, comply generally with the following dimensions taken, where relevant, between centres: (a) a length of about 7,850mm from the connector device (the forward connector) for coupling with a complementary connector device of a tow vehicle, to the forward-most non-steering axle; (b) a length of about 11,515mm from the forward connector and the connector device (the rearward connector) for coupling to the connector device (the tag connector) of the tag trailer; (c) a length of about 13,130mm between the tag connector to the rear end of the tag trailer; and (d) a length of about 24,645mm between the forward connector and the rear end of the tag trailer; with, for a three axle multi-axle system, a spacing between the non-steering axles of about 1,600mm or 1,650mm, and a spacing between the rear non-steering axle and the steering axle of about 2,015mm.

[0020] For a 30 metre B-double having a towing vehicle of the present invention in the style of a skel chassis trailer, or for some forms of bulk or tanker body styles, the corresponding dimensions could be as follows: (a) about 9,340mm; (b) about 12,640mm; (c) about 11,830mm; and (d) about 24,470; with, for a three axle multi-axle system, a spacing between the non-steering axles of about 1,500mm and a spacing between the rear non-steering axle and the steering axle of about 1,800mm.

[0021] These and other essential or preferred features of the present invention will be apparent from the description that now follows.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order that the invention may be more clearly understood and put into practical effect there shall now be described in detail preferred constructions of a towing vehicle for use as part of an articulated vehicle in accordance with the invention. The ensuing description is given by way of non-limitative examples only and is with reference to the accompanying drawings, wherein: [0023] Figure 1 is a side elevation of a B-double combination having a tow vehicle made in accordance with a preferred embodiment of the present invention as the lead trailer; [0024] Figure 2 shows detail of the B-double combination of Figure 1 on an enlarged scale; [0025] Figure 3 illustrates cornering performance curves for the B-double combination of Figure 1, with the curves shown in relation to a scaled down version of that combination corresponding to the scale of those performance curves; [0026] Figure 4 corresponds to Figure 1, but relates to a conventional B-double combination; [0027] Figure 5 corresponds to Figure 2, but relates to the convention B-double combination of Figure 4; [0028] Figure 6 corresponds to Figure 3, but relates to the conventional B-double combination of Figure 4, with the curves shown in relation to a scaled down version of the combination of Figure 4 scaled down to a scale corresponding to those performance curves; and, [0029] Figure 7 shows an underside view of part of the B-double combination of Figure 1, corresponding to the part of the B-double combination shown in detail in Figure 2.

MODES FOR CARRYING OUT THE INVENTION

[0030] In the following detailed description of the invention, reference is made to the drawings in which like reference numerals refer to like elements throughout, and which are intended to show by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilised and that procedural and/or structural changes may be made without departing from the spirit and scope of the invention.

[0031] Figure 1 shows a B-double combination 10 that includes a tractor vehicle 12, a lead trailer 14 and a tag trailer 16. The lead trailer 14 is a tow vehicle made in accordance with a preferred embodiment of the present invention. Figure 2 shows on an enlarged scale the features of trailers 14 and 16 in the area “A” shown in broken outline in Figure 1, while Figure 7 shows the detail of Figure 2 from the underside of Figures 1 and 2. The location of the detail of Figure 7 corresponds also to the dotted circle shown on Figure 3 and highlighted by the reference numeral 7.

[0032] The tractor vehicle 12, of the B-double combination 10 of Figure 1, is of conventional three-axle type. It has a driver cabin 18 mounted on a chassis 20, with the forward two-wheeled axle 22 providing steering for the overall B-double combination 10. At the rear end, the chassis 20 is supported on a two-axle wheeled set 24, with each axle of set 24 carrying two pairs of wheels. To the rear of cabin 18, chassis 20 supports a fifth wheel 26 having an upstanding axis.

[0033] Each of the lead trailer 14 and the tag trailer 16, shown in Figure 1, comprises a curtain sided vehicle, having at least one side of the respective body 15 and 65 provided by a respective side curtain 17 and 67 that is able to be drawn longitudinally for enabling or precluding access to a respective cargo storage space (not shown) within the trailer bodies 15 and 65. Although the lead and tag trailers 14, 16 are shown in the drawings as having curtain sided body styles, it will be appreciated that lead and/or tag trailers 14, 16, may have any suitable body style (such as, for example, any one of the body styles or configurations listed above) without departing from the spirit and scope of the present invention. To illustrate that the respective body style for the lead and/or tag trailer 14, 16, can vary, as desired, the trailer bodies 15, 65, of lead and tag trailers 14, 16, shown in Figures 1 to 3 are shown in dashed-lines.

[0034] Referring to Figures 1 and 2, the lead trailer 14 has a chassis comprising an elongate frame structure 28 on which is supported a deck defining a cargo support surface 30. The frame structure 28 extends from the forward end of body 15, to and beyond the trailing end of body 15. Under a forward end of body 15, frame structure 28 carries a depending king pin (not visible) that is coupled with the fifth wheel 26 of tractor vehicle 12. Thus, the forward end of lead trailer 14 is supported by the fifth wheel 26, on chassis 20 of tractor vehicle 12, while the rear end of trailer 14 is supported on a multi-axle wheel system 32. The arrangement is such that the lead trailer 14 is able to be drawn by tractor vehicle 12, and to pivot on the axis of fifth wheel 26, relative to tractor vehicle 12, during travel on multi-axle wheel system 32. In travel with tractor vehicle 12, lead trailer 14 is fully supported by the fifth wheel 26, on chassis 20, of tractor vehicle 12, and by the multi-axle wheel system 32.

[0035] In the preferred embodiment shown in the drawings, multi-axle wheel system 32 has three wheeled axles comprising a forward wheeled axle 34, an intermediate wheeled axle 35 and a rear wheeled axle 36. The forward and intermediate wheeled axles 34 and 35 comprise a two-axle, non-steering axle set, while rear axle 36 is a self-steering axle, as illustrated schematically in Figure 7 by the multiple positions shown for the wheels 36a of axle 36. In addition to this difference in performance capability between axles 34 and 35 on the one hand and axle 36 on the other hand, the successive axles 34, 35, 36, differ in the spacing between centres. Specifically, the spacing between axles 34 and 35 is less than the spacing between axle 35 and axle 36. In the case of the preferred B-double combination illustrated in Figures 1 to 3 and 7, the spacing between axles 34 and 35 of lead trailer 14 is preferably around 1650mm, whereas the spacing between axles 35 and 36 is preferably around 2015mm, a significant difference of about 16.5%. In addition to the difference in spacing between successive axles 34, 35 and 36, they also differ in positional relationship to frame structure 28. Thus, while the lead axle 34 is wholly under the rear end of trailer body 15, the intermediate axle 35 is under or adjacent to the rear end of trailer body 15, and the rear axle is beyond the rear end of trailer body 15, between the rear end of trailer body 15 and the rear end of trailer 14 defined by frame structure 28. Above axle 36, lead trailer 14 has a fifth wheel 38 with which a king pin (not visible) depending from the underside of the forward end of tag trailer 16 is coupled on an upstanding axis of fifth wheel 38.

[0036] The tag trailer 16 of Figure 1, is similar in overall form to lead trailer 14, and corresponding parts have the same reference numeral plus 50. As much of the detail of tag trailer 16 is the same or similar to that of lead trailer 14, the following description primarily deals with matters of difference between trailers 14 and 16. The frame structure 78 of tag trailer 16 does not extend beyond the rear end of body 65. Also, while the tag trailer 16 is supported to enable travel with lead trailer 14, and pivoting of tag trailer 16 on the axis of fifth wheel 38 relative to lead trailer 14, by the engagement with and support on fifth wheel 38 and by support provided by a tri-axle wheeled axle system 82, the nature of axle system 82 differs from that of multi-axle wheel system 32 of lead trailer 14. Specifically, the axles 84, 85 and 86 all are non-steering axles, and they are substantially uniformly spaced. In the case of the preferred B-double combination illustrated in Figures 1 to 3 and 7, the spacing between centres between intermediate axle 85 and each of forward axle 84 and rear axle 86 is about 1,380mm.

[0037] Figures 4 and 5 show a conventional B-double combination 110 and correspond in part to Figures 1 and 2 and, for ease of understanding, the same reference numerals are used plus 100. Figure 5 shows detail of section B of Figure 4 on an enlarged scale. The essential difference is that, whereas the lead trailer 14 of the preferred B-double combination 10 of Figures 1 and 2 (and Figure 7) is a tow vehicle made in accordance with the present invention, lead trailer 114 of the B-double combination 110 of Figures 4 and 5 is not a vehicle made in accordance with the present invention, but instead is a conventional prior art lead trailer 114. Thus, while conventional lead trailer 114 of Figures 4 and 5 has a tri-axle wheeled axle system 132, located under the rear end of frame structure 128, each of the axles 134, 135 and 136 of the axle system 132 is a non-steering axle. Also, the spacing between axle 135 and each of axle 134 and axle 136 is the same. In the case of the conventional B-double combination illustrated by Figures 4 to 6, the common spacing between successive axles 134, 135 and 136, of axle system 132, is about 1,220mm.

[0038] Figures 3 illustrates cornering performance measurement curves for the preferred B-double combination 10 substantially in accordance with Figures 1, 2 and 7. The preferred B-double combination 10, shown in Figure 3 in relation to the performance curve in a length of roadway having an outer periphery P, is depicted as approaching the curve and as part way through the curve. The preferred B-double combination 10 has a multi-axle wheeled axle system 32 as previously described, with the spacing between axles 34, 35 and 36 specified in that description of axle system 32, with a B-double combination overall length of 29790mm and with other dimensions essentially as detailed earlier herein for a 30 metre long B-double. Figure 6 provides corresponding curves for a conventional B-double combination 110, as in Figures 4 and 5, that differs from the details for Figure 3 only as a consequence of having a multi-axle system 132 as described previously, with the spacing between axles 134,135 and 136 specified in that description of axle system 132. As evidenced by a comparison between Figures 3 and 6, Figure 3 shows that a B-double combination 10 having a lead trailer 14 made in accordance with the present invention has markedly improved cornering performance over a conventional B-double combination 110 having a lead trailer 114 with a conventional multi-axle system 132 with only non-steering axles at a lesser, uniform spacing between axles.

[0039] In Figure 3, the line X-X shows considerably enhanced cornering enabled by the preferred B-double combination 10 of the present invention as compared to the cornering shown by line Y-Y of Figure 6, achieved by the arrangement of a conventional B-double combination 110. The dimensions measured at line X-X are about 8,493mm, whereas the dimension measured at line Y-Y are about 9,327mm. This difference of 834mm is significant and illustrates the ability of a 30 metre long B-double combination 10 made in accordance with the present invention, which exhibits the cornering performance capability of a conventional 26 metre long B-double combination (not shown). Correspondingly, the comparison illustrates an ability to enhance the cornering performance of a tow vehicle combination of any given length, with similar enhancement able to be attained with a B-triple, or with a combination of a rigid body tractor adapted in accordance with the present invention for use with a tag trailer.

[0040] While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification(s). The present invention is intended to cover any variations, uses or adaptations of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth.

[0041] As the present invention may be embodied in several forms without departing from the spirit of the essential characteristics of the invention, it should be understood that the above described embodiments are not to limit the present invention unless otherwise specified, but rather should be construed broadly within the spirit and scope of the invention as defined in the attached claims. Various modifications and equivalent arrangements are intended to be included within the spirit and scope of the invention. Therefore, the specific embodiments are to be understood to be illustrative of the many ways in which the principles of the present invention may be practiced.

[0042] Where the terms “comprise”, “comprises”, “comprised” or “comprising” are used in this specification, they are to be interpreted as specifying the presence of the stated features, integers, steps or components referred to, but not to preclude the presence or addition of one or more other features, integers, steps, components to be grouped therewith.

Claims (17)

1. CLAIMS:

   1. A towing vehicle for use as part of an articulated vehicle, and suitable for use as a lead trailer of a B-double vehicle, or as a first and/or a second trailer of a B-triple vehicle, or as a rigid body truck for towing a semi-trailer, wherein the towing vehicle includes an elongate frame structure that has a leading end and a trailing end and that is mounted on a multi-axle wheel system, from adjacent or near to the leading end and extending over a major part of the length of the frame structure towards the trailing end, the frame structure defines a cargo support surface, between the trailing end of the frame structure and a trailing end of the cargo support surface, the frame structure carries a connector device by which the towing vehicle can be coupled to a mating connector device at a leading end of a tag semi-trailer whereby the towing vehicle is able to draw the tag trailer and to pivot about an upstanding axis relative to the tag trailer, and wherein the multi-axle wheel system has at least three wheeled axles, including a set of two or three non-steering axles spaced along the frame structure and, spaced between the set of non-steering axles and the rear end of the frame structure, one steering axle or a set of two steering axles, whereby the multi-axle wheel system enables travel of the towing vehicle and is located at or adjacent to the trailing end of the frame structure, such as with the one steering axle or at least a rearmost one of the two steering axles located between the trailing ends of the cargo support surface and the frame structure.
2. 2. The towing vehicle according to claim 1, wherein the connector device carried by the frame structure is a turntable or fifth wheel with which a depending king pin at the leading end of the tag trailer is able to be coupled.
3. 3. The towing vehicle according to claim 1 or claim 2, wherein the towing vehicle comprises a semi-trailer for a B-double or a B-triple, and the towing vehicle has a connector device spaced from the forward end of the frame structure by which the semi-trailer can be coupled to a mating connector device at a trailing end of a tractor tow vehicle whereby the trailer is able to be drawn by the tractor vehicle and to pivot about an upstanding axis relative to the tractor vehicle.
4. 4. The towing vehicle according to claim 3, wherein the connector device spaced from the forward end of the frame structure is a depending king pin by which the towing vehicle is able to be coupled to a connector device comprising a turntable or a fifth wheel at the trailing end of the tractor vehicle.
5. 5. The towing vehicle according to claim 3 or claim 4, wherein the multi-axle wheel system typically comprises the sole wheel support for the frame structure.
6. 6. The towing vehicle according to claim 1 or claim 2, wherein the towing vehicle comprises a rigid body truck.
7. 7. The towing vehicle according to claim 6, wherein the towing vehicle has, at the forward end of the support frame, a driver’s cabin housing a drive motor and at least front steering wheels, with a transmission operable between the motor and a driven axle of the set of non-steering axles.
8. 8. The towing vehicle according to any one of claims 3 to 5, where the towing vehicle has a form selected from: (i) an enclosed, curtain sided trailer body style, such as in any of the main configurations of flat, single drop and double drop deck forms for the cargo support surface; (ii) a solid side wall enclosed body style for a refrigerated/freezer vehicle; (iii) a solid side wall enclosed body style for an ambient temperature pantechnicon; (iv) an open trailer with a typically flat deck, with forward and rearward racks and various deck configurations; (v) an open, chassis only skeletal deck or “skel”, such as for temporarily affixing shipping containers and the like; (vi) a bulk carrying body style or a tipping bulk carrying body style, such as for carrying sand, dirt, gravel or other bulk commodities; and, (vii) a fluid carrying body style, such as a tanker for carrying liquids or gas.
9. 9. The towing vehicle according to any one of claims 1 to 8, wherein the multiaxle wheel system has a set of two non-steering axles and, rearward of that axle set, one steering axle.
10. 10. The towing vehicle according to any one of claims 1 to 8, wherein the multiaxle wheel system has a set of three non-steering axles and, rearward of that axle set, one steering axle or two steering axles.
11. 11. The towing vehicle according to any one of claims 1 to 10, wherein the, or each, steering axle is self-steering.
12. 12. The towing vehicle according to any one of claims 1 to 10, wherein the, or each, steering axle is steerable under the action of a control mechanism, such as a mechanism that is hydraulically, pneumatically or electrically operable.
13. 13. The towing vehicle according to any one of claims 1 to 12, wherein the, or each, steering axle is controlled by an hydraulic, pneumatic or electrically operable locking mechanism by which the, or each, steering axle is able to be held against steering above a nominal speed, such as from 30 to 40 kilometres per hour, whereby steering by the, or each, steering axle is permitted only during low speed travel, such as when required for tight turns, such as encountered in built up areas and, at higher speeds at which the, or each, steering axle is locked, the or each steering axle performs in the same way as a non-steering axle.
14. 14. The towing vehicle according to any one of claims 1 to 13, wherein there is a centre-to-centre distance between the successive non-steering axles that is less than the centre-to-centre spacing between (i) the rearmost non-steering axle and the, or the forward, steering axle and where there are two steering axles (ii) between the successive steering axles.
15. 15. The towing vehicle according to claim 14, wherein the spacing between successive non-steering axles is in the range of from 1,450mm to 1,700mm, and the centre-to-centre spacing between the rearmost non-steering axle and the, or the forward, steering axle is in the range of from 1,750mm to 2,065mm.
16. 16. The towing vehicle according to claim 14 or claim 15, wherein the spacing between successive non-steering axles is in the range of from 1,475mm to 1675mm, and the centre-to-centre spacing between the rearmost non-steering axle and the, or the forward, steering axle is in the range of from 1,775mm to 2,040mm.
17. 17. The towing vehicle according to any one of claims 14 to 16, wherein depending on the form of the towing vehicle, the spacing between successive nonsteering axles is about 1,500mm, 1,600mm or 1,650mm, and the centre-to-centre spacing between the rearmost non-steering axle and the, or the forward steering axle is about 1,800mm or 2,015mm.