A TRAIL E R AS S E MB LY

Field of the Invention

[0001 ] The present invention relates to a trailer assembly a nd in particular to a method and a pparatus of a steering and support of a trailer assembly for trans porting long loads.

[0002] The invention has been developed primarily for use in transporting railway lines and long plastics conduits and will be described hereinafter with reference to this a pplication. However, it will be appreciated that the invention is not limited to this particular field of use.

Background of the Invention

[0003] It is genera lly difficult and expensive to trans port very long (about 25 metres or more) items such as railway lines or plastic pipes. P resently, extendable trailers are used to transport these materials. It is desirable to provide a much more cost-effective way to transport such materials, preferably with an increase in pay load.

[0004] It is known on double B trailers to have multiple trailers which a re connected lengthwise with pivotal connections between each. This is acceptable a nd useful if carrying large quantities of loads but only where the size of the load is no greater than any one of the trailers. With such pivotal connections of loads the following trailer is a ble to pivot around a vertica l axis of the pivota l join to the preceding trailer and thereby move out of rectilinea r configuration of the multiple trailers into a curvilinear configuration. This has no consequence to the load if each is withheld in one only of respective trailers.

[0005] The difficulty is when loads extend beyond the length of a trailer. If the trailers were pivota lly mounted a nd the following trailer is able to pivot around a vertical axis of the pivotal join to the preceding trailer and thereby move out of rectilinear configuration of the multiple trailers into a curvilinear configuration, the load would either need to flex to the curvilinear configuration or break or cut across the trailers and s hift and still break. One aspect is that when two trailers move from the rectilinear configuration of the multiple trailers into a curvilinea r configuration the shortest dista nce between the front of the front trailer and the rea r of the rear trailer becomes shorter. Also, the shortest distance being a straight line between those two points no longer overly the bodies of the trailers. In essence, such systems cannot support a nd transport long loads.

[0006] The present invention seeks to overcome or substantially ameliorate at least some of the deficiencies of the prior art or to at least provide a n a lternative. [0007] It is to be understood that, if any prior art information is referred to herein, such reference does not constitute a n admission that the information forms part of the common general knowledge in the art, in Australia or any other country.

S ummary of the Invention

[0008] According to a first aspect, the present invention provides a trailer assembly comprising: a lead trailer comprising a body having a front end and a rear end, the front end comprising connection means for connection to a prime mover and the rear end comprising at least one lead trailer wheel assembly having a self-steering axle; a rea r trailer comprising a body having a front end and a rear end, the rear end comprising at least one rear trailer wheel assembly; and coupling means between the lead trailer and the rea r trailer, the coupling mea ns allowing the rear trailer to pivot relative to the lead trailer only about a generally horizontal coupling axis extending transverse to the longitudinal length of the lead trailer.

[0009] The invention in a nother aspect provides a trailer assembly comprising: a lead trailer comprising a body having a front end and a rear end, the front end comprising connection mea ns for connection to a prime mover a nd the rear end comprising at least one lead trailer wheel assembly having a self-steering axle; a rea r trailer comprising a body having a front end and a rear end, the rear end comprising at least one rear trailer wheel assembly; and a coupling mea ns between the lead trailer and the rear trailer, wherein the coupling means comprises two laterally spaced connections between following connected trailers to substantially prevent pivoting of one trailer to a nother a round a vertical axis.

[00010] P referably the coupling means allows the rear trailer to pivot relative to the lead trailer substantially about a generally horizontal coupling axis extending tra nsverse to the longitudinal length of the lead trailer.

[0001 1 ] The trailer can include a steering control means for controlling at least one lead trailer wheel assembly of a multiple axle wheel assembly acting separately or in unison and at least one rear trailer wheel assembly of a multiple axle wheel assembly acting separately or in unison wherein the operation between the lead trailer wheel assembly and the rea r trailer wheel assembly is coordinated with the coupling.

[00012] The steering control means controls automatically, the at least one lead trailer wheel assembly of a multiple axle wheel a nd the at least one rea r trailer wheel assembly of a multiple axle wheel.

[00013] The trailer automatic control of the steering control means can be effected when the at least one lead trailer wheel assembly of a multiple axle wheel and the at least one rear trailer wheel assembly of a multiple axle wheel reach predetermined effecting angles relative to the angle of the at least one lead trailer wheel assembly or the at least one rear trailer wheel assembly to the first and second trailer.

[00014] P referably the automatic control of the steering control means is effected when the at least one lead trailer wheel assembly of a multiple axle wheel and the at least one rear trailer wheel assembly of a multiple axle wheel reach predetermined effecting angles relative to the angle of the prime mover to the first and second trailer.

[00015] The steering control means can control steering automatically such that when a turn in a first direction is effected by the steering wheels of a prime mover:

a. initially the supporting wheels of the front trailer are turning in the first direction until reaching a predetermined maximum turning a ngle and while the supporting wheels of the rear trailer are in a straight-ahead position; and b. the ha lting of the turning of the supporting wheels of the front trailer a nd the turning in a second direction being to the opposite side of first direction of the supporting wheels of the rear trailer so that the rear wheels ca n steer in a continuous C- curve or reverse C - curve by the motion effected by the steering a nd pulling motion of the prime mover a nd the front trailer;

c. the straightening and or turning of the steering wheels of the prime mover further switching to effect, by the motion effected by the steering and pulling motion of the prime mover back to a substantia lly straight position of the supporting wheels of the front trailer and the supporting wheels of the rear trailer returning to a straight-ahead position.

[00016] The steering control means includes one or more of:

a. hydraulic cylinders

b. pneumatic actuators

c. electric actuators

d. mechanical mea ns

to aid control of the at least one lead trailer wheel assembly of a multiple axle wheel a nd the at least one rear trailer wheel assembly of a multiple axle wheel.

[00017] P referably, the connection means of the lead trailer comprises a kingpin.

[00018] P referably, the lead trailer comprises at least two lead trailer wheel assemblies each having a self-steering axle. [00019] More preferably, the lead trailer comprises at least three lead trailer wheel assemblies each having a self-steering axle.

[00020] P referably, the rear trailer comprises at least one rear trailer wheel assembly having a self-steering axle.

[00021 ] More preferably, the rear trailer comprises at least two rear trailer wheel assemblies.

[00022] More preferably, the rear trailer comprises at least three rear trailer wheel assemblies, at least one of the rea r trailer wheel assemblies having a self-steering axle.

[00023] P referably, the coupling means comprises a coupling assembly comprising at least two laterally s paced connection means between the lead trailer a nd the rear trailer.

[00024] More preferably, the coupling means comprises a coupling assembly comprising at least two laterally spaced fifth wheel couplings provided at the rear end of the lead trailer and at least two corresponding kingpins provided at a front end of the rear trailer.

[00025] P referably, the rear trailer comprises a centra l kingpin for connecting with a fifth wheel coupling of the prime mover.

[00026] P referably, the lead trailer comprises a bulkhead at the front end thereof.

[00027] P referably, the lead trailer comprises a load floor or load space which extends from the front end to a bout three quarters of the length towa rds the rear end.

[00028] P referably, the rear end of the lead trailer includes an upper portion which is at a reduced height level relative to the load floor or load space.

[00029] P referably, at least a portion of the coupling means is disposed at the upper portion.

[00030] P referably, the rear trailer comprises a bulkhead at the rear end thereof.

[00031 ] P referably, the rear trailer comprises a load floor or load space which extends from the front end to the rear end thereof.

[00032] P referably, the rear trailer comprises a reduced width portion for most of its length.

[00033] P referably, the coupling means substantia lly prevents the rear trailer from pivoting relative to the lead trailer about a ny vertical axis.

[00034] P referably, the coupling means substantia lly prevents the rear trailer from pivoting relative to the lead trailer about a horizontal axis generally a ligned with the longitudinal length of the lead trailer. [00035] P referably, the coupling means provides a maximum decline angle of the rear trailer relative to the lead trailer of a bout 8e a nd/or a maximum incline angle of about 8e.

[00036] The present invention also provides a transport assembly comprising a prime mover to which is attached the trailer assembly in accorda nce with the above, the lead trailer being connected to the prime mover and the rear trailer being coupled to the lead trailer.

[00037] P referably, the transport assembly further comprises a load carried by the trailers, the load extending from the front end of the lead trailer to the rear end of the rea r trailer.

[00038] The present invention also provides a transport assembly comprising a prime mover to which is attached the trailer assembly in accordance with the above, the rear trailer being connected to the prime mover and the lead trailer being loaded onto the rear trailer.

[00039] The present invention also provides a coupling assembly for coupling a lead trailer to a rear trailer, the coupling assembly a llowing the rea r trailer to pivot relative to the lead trailer only about a generally horizontal coupling axis extending transverse to the longitudinal length of the lead trailer.

[00040] The coupling means can comprise two latera lly spaced connections between following connected trailers to substantia lly prevent pivoting of one trailer to another a round a vertical axis.

[00041 ] The trailer assembly ca n have a locking means on at least one lead trailer wheel assembly having at least one self-steering axle or a multiple axle wheel assembly acting in unison and a locking means on the rear trailer comprises a rear trailer wheel assembly having at least one self-steering axle or a multiple axle wheel assembly acting in unison.

[00042] In a pa rticularly preferred form, the trailer assembly of claim 3 further includes a control for controlling the locking mea ns automatically such that

a. initially the locking mechanism is a ble to effect the supporting wheels of the front trailer to be in an unlocked self-steering mode until reaching a predetermined maximum turning angle and while the supporting wheels of the rear trailer are in a locked straight-ahead position; and

b. switching of the locking mechanism effects the locking of the supporting wheels of the front trailer and unlocking of the supporting wheels of the rear trailer so that the rea r wheels can self-steer by the motion effected by the steering and pulling motion of the prime mover a nd the front trailer; c. further switching of the locking mechanism to effect, after self-steering by the motion effected by the steering and pulling motion of the prime mover back to a substantially straight position, of the supporting wheels of the front trailer to be in an unlocked self-steering mode a nd the supporting wheels of the rear trailer are in a locked straight-ahead position.

[00043] P referably, the coupling assembly comprises at least two laterally spaced connection mea ns between the lead trailer a nd the rear trailer.

[00044] More prefera bly, the coupling assembly comprises at least two latera lly spaced fifth wheel couplings provided at the rear end of the lead trailer and at least two corresponding kingpins provided at a front end of the rear trailer.

[00045] The present invention also provides a method of coupling a lead trailer to a rear trailer, the method allowing the rear trailer to pivot relative to the lead trailer only a bout a generally horizontal coupling axis extending tra nsverse to the longitudinal length of the lead trailer.

[00046] In one form the trailer assembly coupling means provides a high torsion connection and wherein the coupling means includes an elongated sha ped engaging means mounted pivotably between two supports so as to extend in a transverse direction to the elongated length a first of the trailers; a raised shape receiving means that is hollow and overlies a cut-out in a second of the trailers for receiving and engaging the elongated shaped engaging means; a locking mea ns for locking laterally in relative fixed positions the elongated sha ped engaging mea ns a nd the raised sha pe receiving means; wherein the connected trailers are substa ntially prevented from relatively pivoting around a vertical axis but have limited pivoting around a transverse horizonta l axis to allow limited different dipping relative to each other.

[00047] The present invention also provides a trailer comprising a body having a front end and a rear end, the front end comprising connection means for connection to a prime mover and the rear end comprising at least two wheel assemblies each having a self-steering axle, the rear end further comprising at least two laterally spaced fifth wheel couplings.

[00048] The present invention also provides a trailer comprising a body having a front end and a rear end, the front end comprising connection means for connection to a prime mover a nd the rear end comprising at least two wheel assemblies, at least one of the wheel assemblies having a self-steering axle, the front end further comprising at least two laterally spaced kingpins. [00049] P referably, at least one of the lead and the rea r trailers is a n extenda ble trailer.

[00050] In one embodiment, the at least one rea r trailer wheel assembly comprises a manually steered axle.

[00051 ] In another embodiment, the rea rtrailer comprises at least two rear trailer wheel assemblies, at least one of the rear trailer wheel assemblies having a self-steering axle a nd at least another one of the rear trailer wheel assemblies having a manually steered axle.

[00052] In one form of the invention the trailer assembly can have the lead trailer comprising at least one lead trailer wheel assembly each having a self-steering axle and the rear trailer comprising at least one rear trailer wheel assembly each having a self-steering axle.

[00053] P referably the rea r trailer wheel assembly self-steering axles are operative in accordance with the determined operation of the at least one lead trailer wheel assembly self- steering axle when in a slow turning operation. The slow turning operation is undertaken at less tha n 30 kilometres per hour.

[00054] The rea r trailer wheel assembly self-steering axles ca n be locked until the determined operation of the at least one lead trailer wheel assembly self-steering axle reaches a limiting turn a ngle. T he limiting turn a ngle is a predetermined angle which can be in the ra nge of 4 degrees to 10 degrees and is preferably substantially of 6 degrees.

[00055] The determined operation of the at least one lead trailer wheel assembly self- steering axle ca n be detected wireless ly by a detector mounted at or near the rear trailer wheel assembly self-steering axles. The detector preferably is an optical sensor detecting the turning a ngle of the at least one lead trailer wheel assembly self-steering axle and whether a limiting turn angle is reached.

[00056] The detector can be associated with a activator for locking or unlocking the rear trailer wheel assembly self-steering axles upon the at least one lead trailer wheel assembly self-steering axle being detected by the detector to have reached the limiting turn a ngle and unlock the rear trailer wheel assembly self-steering axles or reaching a straight a head angle a nd locking the rear trailer wheel assembly self-steering axles. P referably the activator for locking or unlocking the rea r trailer wheel assembly self-steering axles is a solenoid.

[00057] The invention also provides a method of tra nsporting and steering extensive elongated loads using a prime mover and multiple elongated trailers each having a set of rear wheels comprising the steps of:

a. P roviding a pivotal connection at a front of a front trailer around a vertical axis for connection to and pulling by a prime mover; b. P roviding a connection between an overlapping rear of the front trailer and the front of the rea r trailer over a rear set of supporting wheels of the front trailer c. P roviding latera l sta bility coupling systems on the sides of the overlapping rea r of the front trailer and the front of the rear trailer substantially preventing pivoting rotation of one trailer to the connected other trailer around a vertica l axis;

d. P roviding a locking mechanism for a part of or the set of supporting wheels of the front trailer and the rear trailer;

e. Controlling the locking mechanism of the part of or the set of supporting wheels of the front trailer a nd the rear trailer such that generally, if the supporting wheels of the front trailer are locked, the supporting wheels of the rear trailer a re unlocked and able to self-steer by the motion effected by the steering and pulling motion of the prime mover.

[00058] In the method, a turn can be effected by steering the prime mover in the steps of:

i. initially the locking mechanism effecting the supporting wheels of the front trailer to be in an unlocked self-steering mode until reaching a predetermined maximum turning a ngle and while the supporting wheels of the rea r trailer a re in a locked straight-ahead position; and ii. switching of the locking mechanism to effect the locking of the supporting wheels of the front trailer and unlocking of the supporting wheels of the rear trailer so that the rear wheels can self-steer by the motion effected by the steering a nd pulling motion of the prime mover a nd the front trailer;

iii. further switching of the locking mechanism to effect, after self-steering by the motion effected by the steering and pulling motion of the prime mover back to a substantially straight position, of the supporting wheels of the front trailer to be in an unlocked self-steering mode a nd the supporting wheels of the rear trailer are in a locked straight-ahead position.

[00059] The lateral stability coupling systems includes providing provides a high torsion connection and wherein the coupling means can include a n elongated shaped engaging mea ns mounted pivotably between two supports so as to extend in a transverse direction to the elongated length a first of the trailers; a raised sha pe receiving means that is hollow and overlies a cut-out in a second of the trailers for receiving and engaging the elongated shaped engaging means; a locking mea ns for locking laterally in relative fixed positions the elongated sha ped engaging means and the raised shape receiving means ; wherein the connected trailers are substantially prevented from relatively pivoting around a vertical axis but have limited pivoting around a transverse horizonta l axis to allow limited different dipping relative to each other.

[00060] It can be seen that in one form the invention provides broadly 2 main issues:

I The two trailers have a coupling that generally limits articulation between the trailers to rotation about a horizontal axis that is perpendicula r to the longitudinal axis of the trailers.

I The steering of the axles on the trailers is controlled to ensure that the vehicle swept path meets transport department requirements.

[00061 ] Other aspects of the invention are also disclosed.

B ri ef Des c ri ption of the Drawi ngs

[00062] Notwithstanding a ny other forms which may fall within the scope of the present invention, preferred embodiments of the present invention will now be described, by way of examples only, with reference to the accompanying drawings in which:

[00063] F igure 1 is a side view of a transport assembly comprising a trailer assembly in accordance with a first preferred embodiment of the present invention in an in-use configuration, with the trailer assembly having a front trailer and a reartrailer extending linea rly a nd being pivotally connected in a first manner, and shown attached to a prime mover and carrying a load of rail lengths;

[00064] F igure 2 is a top view of the transport assembly of Figure 1 when moving in a straight direction;

[00065] F igure 3 shows schematic side views of the tra nsport assembly of F igure 1 with the prime mover at a maximum decline angle relative to the lead trailer, with (a) the rear trailer at a maximum decline angle relative to the lead trailer and (b) the rear trailer at a maximum incline a ngle relative to the lead trailer

[00066] F igure 4 is a top view of the trans port assembly of F igure 1 schematically showing the transport assembly performing a left turn in accordance with a first embodiment in which the rear axial wheels of the rear set of triaxial wheels are operating individua lly and the middle set of triaxial wheels are operating in unison; [00067] F igures 5 and 6 are a side view and top view respectively of a transport assembly comprising a trailer assembly in accordance with a second preferred embodiment of the present invention in an in-use configuration, the trailer assembly having a front trailer a nd a rea r trailer extending linearly a nd being pivotally connected in a second manner, a nd shown attached to a prime mover and carrying a load of rail lengths;

[00068] F igures 7 and 8 are a detail of a side view a nd top view respectively of a joining of the trailer assembly having a front trailer and a rear trailer extending linearly and being pivota lly connected in a second manner of Figures 5 a nd 6;

[00069] F igures 9 to 12 are details of operative connected parts of the latera l pivot supports in the form of pivot and wedge assemblies on the sides of the front trailer and a rear trailer extending linea rly and being pivota lly connected in a second manner of Figures 5 and 6;

[00070] F igure 13 is a swept path diagram of the transport assembly of F igure 1 or F igures 5 and 6, schematica lly showing the tra ns port assembly performing a left turn in various positions 201 to 204 and back to 201 ;

[00071 ] F igures 14 to 17 are overhead diagrammatic views of the operation of the sets of triaxial wheels when progressing between positions 201 to 204 and back to 201 identified in F igure 13;

[00072] F igures 18 a nd 19 are diagrammatic views of the control of steering by use of the relative rotation of a connection at the front end of the trailer to the prime mover;

[00073] F igures 20, 21 a nd 22 a re diagrammatic views of different stages of turning and different views while making use of the relative rotation of Figures 18 and 19 and transferring steering instructions to wheel set at rear of front and rear of rear trailers by mecha nica l, hydraulic and electric means respectively; a nd

[00074] F igure 23 is a side view of the transport assembly of F igure 1 in the transport configuration, with the lead trailer loaded onto the rear trailer.

Des c ri ption of E mbod iments

[00075] It should be noted in the following description that like or the same reference numerals in different embodiments denote the same or similar features.

[00076] It s hould be noted that the embodiments s how different combinations of:

a. Multiple elongated trailer systems; b. Lateral sta bility coupling systems for joining of the multiple elongated trailer systems;

c. Axial wheel locking systems; and

d. S teering control systems.

However various combinations are within the scope of the invention. Therefore, although the description describes each element and might describe it with one other of the features but is done so as to be illustrative and not to be limited to that combination.

[00077] F igures 1 and 2 show a first embodiment of a transport assembly which comprises a prime mover 100 to which is attached a trailer assembly of a front elongated trailer 120 and a rear elongated trailer 160. The trailer assembly 10 in the embodiment is shown carrying a load of rail lengths 124 that extend over the extended lengths of the combination of the front elongated trailer 120 and the rear elongated trailer 160. It can be seen therefore that the front elongated trailer 120 a nd the rear elongated trailer 160 need to remain in a collinear following configuration to carry such elongated loads extending over the extended lengths of the combination of the front elongated trailer 120 a nd the rear elongated trailer 160.

[00078] The prime mover 100, as is known, comprises front steering wheels 102, rear drive wheels 104, and a fifth wheel coupling 106. The trailer assembly 10 comprise a lead trailer 120 (A-trailer) and a rear trailer 160 (B-trailer), which are both generally flatbed trailers.

[00079] The lead trailer 20 comprises a body 22 having a front end 24 and a rear end 26. The lead trailer 20 also comprises a bulkhead 28 at the front end 24, a nd a load floor or load space 30 which extends from the front end 24 to a bout three quarters of the length towards the rea r end 26. The rear end 26 includes a n upper portion 32 which is at a reduced height level relative to the load floor or load space 30. The front end 24 includes a kingpin 25 at a lower surface thereof for coupling to the fifth wheel coupling 106 of the prime mover 100.

[00080] The upper portion 32 of the rear end 26 includes lateral stability coupling systems 1 50 for joining of the multiple elongated trailers 120 and 160. In this embodiment, the lateral stability coupling systems 1 50 comprises two fifth wheel couplings 188 and 188 mounted on the top rear of the front trailer 120 in a laterally spaced configuration near either side of the front trailer 120.

[00081 ] The rear end 26 of the trailer 120 is supported by three axial wheel assemblies 136A to 136C , each comprising a respective self-steering axle. The load floor or load space 30 comprises two spaced load ba rs 40A and 40B which extend tra nsversely to the longitudinal length of the lead trailer 120. [00082] The rear trailer 160 comprises a body having a load floor or load space 70 which extends from the front end 64 to a rea r bulkhead 68 at the rear end 66. The front end 64 includes two latera lly spaced kingpins 65 at a lower surface thereof for respective coupling to the fifth wheel couplings 188 of the lead trailer 120. The front end 64 a lso includes a central kingpin 69 at the lower surface thereof for coupling to the fifth wheel coupling 106 of the prime mover 100 when required as further described below.

[00083] The rear end 66 is supported by three wheel assemblies 138A to 138C, with the wheel assemblies 138A and 138B having fixed axles, a nd rearmost wheel assembly 138C comprising a self-steering axle.

[00084] The load floor or load s pace 70 a lso comprises two spaced load bars 80A and 80B which extend transversely to the longitudina l length of the rear trailer 160. The load floor or load space 70 of the body of the rear trailer 160 can include a reduced width portion for most of its length to lighten its weight.

[00085] In the embodiment, the trailer assembly 10 can be used to transport a load 124 of twenty-five metre rail lengths, which a re a rranged in an a rray of fourteen rail lengths wide a nd two rail lengths high (twenty-eight rail lengths in tota l). The load 124 of rail lengths are supported by the load ba rs 40A a nd 40B on the front trailer 120 and 80A and 80B, with intermediate load bars between the first and second rail length layers at the position of and overlying the load ba rs 40A, 40B a nd 80A and 80B.

C OUP LING - F ifth Wheel to P rime Mover

[00086] Referring to Figure 3, the fifth wheel coupling 106 of the prime mover 100 to which is coupled the kingpin 25 of the lead trailer 20 in use provides a tow point, as well as a point of articulation between the prime mover 100 and the lead trailer 20. As is known, the fifth wheel coupling 106 can pivot a bout a pivot axis which is horizontal (generally parallel to the ground) a nd transverse (perpendicular) to the longitudinal length of the prime mover 100. This allows the prime mover 100 to pivot relative to the lead trailer 120 at a maximum decline a ngle 126 of about 8e. The kingpin 25 also provides a vertical axis articulation point between the prime mover 100 and the lead trailer 20.

C OUP LING - F ifth Wheel from T railer A to T railer B

[00087] F ifth wheel couplings 134a and 134b can be used to connect leading trailer 120 a nd rea r trailer 160. However, such systems are preferably only usea ble for up to 5 to 6 tonnes per triaxle of wheels. This is due to the high torsion rates for greater weights over the length of the trailers 120, 160 a nd only held by two laterally s paced fifth wheel couplings 188 which thereby resist lateral and rotationa l torsion.

[00088] The coupling assembly 1 50 between the lead trailer 120 and the rear trailer 160, comprising the two fifth wheel couplings 188 to which a re coupled the respective kingpins 25 a nd 65 in use, provides a tow point between the lead trailer 120 and the rear trailer 160.

[00089] The two laterally s paced fifth wheel couplings 188 a re a lso respectively pivota ble about respective, and aligned, pivot axes which are also horizontal (generally pa rallel to the ground) and perpendicular (transverse) to the longitudinal length of the lead trailer 120. The two pivot axes define a coupling axis which allows the rear trailer 160 to pivot relative to the lead trailer 120 only about the horizontal coupling axis. The coupling assembly 150, from the lateral spacing of the fifth wheel couplings 188 and the respective kingpins 25 a nd 65, substantially prevents the rear trailer 160 from pivoting relative to the lead trailer 120 about a ny vertical axis.

[00090] As shown in F igure 3, the rea r trailer 160 is maintained in a generally a ligned orientation to the lead trailer 120. The coupling axis provides a maximum decline angle 128 of the rear trailer 60 relative to the lead trailer 120 of about 8¾ or a maximum incline angle 130 of a lso about 8e. The load 120, in the embodiment being rail lengths 122, bend when the rea r trailer 160 pivots about the horizontal coupling axis relative to the lead trailer 120.

C OUP LING - High Torsion C oupling from Trailer A to Trailer B

[00091 ] The high torsion coupling 200 is a novel and inventive way of connecting leading trailer 120 and rea r trailer 160. T his system is useable for up to 20 tonnes per triaxle of wheels. T his is due to the particular engaging structure a llowing absorption of high torsion rates without brea king for greater weights over the length of the trailers 120, 160 when only held by two pivoting fifth wheel couplings 188 in the coupling system 1 50.

[00092] Referring to F igures 7 and 8 there are two laterally placed high torsion couplings 200 each of which comprises a first connection 140 at an upper rear portion of the first trailer 120 being Trailer A that connects a nd couples with a second interengaging portion 180 at a front portion of the second trailer 160 being trailer B. The location of the first connection 140 at the rear of the first trailer 120 is above the triaxle wheel set 136. However, the tray 130 of the first trailer 120 dips at the rear portion to support a framework 139 for the first connection 140 so thatthe front portion of the second trailer 160 can overly the rear portion of the front trailer 120 and the second connection 180. [00093] F igure 9 that shows the first connection 140 upper rear portion of the first trailer 120 being Trailer A that connects and couples with a second interengaging portion 180 at a front portion of the second trailer 160 being trailer B.

[00094] F igures 1 1 and 12 show details of the operative connected parts 140, 180 of the lateral pivot coupling supports 200 in the form of pivot and wedge assemblies on the sides of the rear of the front trailer 120 a nd on the front of the rear trailer 160.

[00095] The first connection 140 includes a n elongated shaped engaging means 141 in the form of a wedge block which extends transversely across a portion of the front trailer 120 from adjacent a lateral side at the rea r. T he wedge block 141 has an inverted flanging U- sha ped consta nt cross-section a long its length. This wedge block 141 extends from a strengthened planar support 145 mounted on the floor 30 at the lateral side of the tray of the front trailer 120. The wedge block extends to a pla na r tall limit plate 146 mounted on the floor 30 of the front trailer 120 at an inner lateral position and extending pa rallel to the strengthened plana r support 145. The wedge block 141 is mounted on a horizonta l pivot pin 147 supported by the spaced pa ra llel strengthened pla nar support 145 and the planar tall limit plate 146. This a llows the wedge block to rock around a horizonta l pivot.

[00096] The sha ped engaging means of the wedge block 141 has multiple pla nar surfaces 142 around its upper circumference with bevelled edges 143 at the linear vertices between the planar surfaces. In one form the shaped engaging mea ns 141 is a wedge block being substantially a rectangula r block but with an outwardly flared vertical cross-section having a wider base than the top.

[00097] The planar tall limit plate 146 extends above the height of the wedge block 141 a nd includes a receiving hole 148 in the upper part to receive and limit a part of the second connection 180 as will be described later.

[00098] The second connection 180 is mounted integrally on the top of the front 65 of the second trailer 160 but with openings extending through the floor 70 so as to receive pa rts of the first connection 140 of the underlying back end 26 of the front trailer 120.

[00099] The second connection 180 primarily has a raised shape receiving means 181 that is a hollow elongated with consta nt inverted U-s hape cross-section 182 that closely complements the inside sha pe and dimension of outwardly flared vertical cross-section of the wedge block 141 has multiple planar surfaces 142 a round its upper circumference with bevelled edges 143 at the linear vertices between the pla nar surfaces. T he body of the rear trailer 160 includes a cut-out 183 for a llowing the wedge 141 of the underlying rear end 26 of the front trailer 120 to protrude through to engage the undersurface of the wedge receiver 181 on the overlying front end 64 of the rear trailer 160. [000100] As shown by the interaction of wedge block 141 and wedge receiver over an elongated length and with close matching s hapes there is a high contact between the two that stops rotation of first trailer 120 and second trailer 160 a round a vertical axis. The outward flange and bevelled corners further lock the shapes together.

[000101 ] It should be noted that due to the wedge block 141 being mounted on the horizontal pivot 147 as shown in F igure 3, the rear trailer 160 is maintained in a generally a ligned orientation to the lead trailer 120. The coupling axis provides a maximum decline angle 128 of the rear trailer 60 relative to the lead trailer 120 of about 8e, or a maximum incline angle 130 of a lso about 8e. The load 120, in the embodiment being rail lengths 122, bend when the rear trailer 160 pivots about the horizontal coupling axis relative to the lead trailer 120.

[000102] The second connection 180 further includes a front portion 183 of the outer edge of the cut-out 182 adjacent the outer end of the wedge receiver 181 and a rear portion 184 of the cut-out 183 at the other end of the wedge receiver 181. The front portion 183 of the cut-out 182 can receive the strengthened plana r support 145 mounted on the floor 30 at the lateral side of the tray of the front trailer 120 and protruding into the cut-out from underneath. The rear portion 184 of the cut-out 182 can receive the plana r tall limit plate 146 mounted on the floor 30 of the front trailer 120 This a llows for the pivotally mounted wedge block 141 to engage the wedge receiver 181.

[000103] It can be seen that the high torsion lateral stability coupling systems 200 at spaced lateral sides of the overlap of front and reartrailers 120, 160 join the multiple elongated trailers in a fixed linear following configuration in order to transport elongated loads 124 while a llowing some vertica l dipping of one trailer relative to a nother such as shown in Figure 3. This provides a stability which thereby a llows the steerability of the loads due to the combination with locking system and control of locking as will be described later.

[000104] Although this horizonta l pivoting is a llowable it is important as will be described further later that in operation the front and rea r trailers 120, 160 remain collinear and do not pivot around a vertical axis. Only in that way will the control steering system be able to come into play.

[000105] However, it is important when connecting a second rear trailer 160 to a front trailer 120 that there is some leeway for connection but rigidity in operation. This is provided by a limit pin 186 a nd receiving mount in front rigid plate 185 of the second connection 180. The rigid plate 185 overlies the wedge receiver 181 and is fixed to the body of the trailer 160. The rigid pin is mountable into a receiving hole in the

[000106] Thereby while the limit plate 146 is able to protrude through the rear portion 184 of the cut-out 182 and present the receiving hole 148 in the upper pa rt, it does not yet receive and is not limited by a part of the second connection 180. Instead, due to the sizing of the front and rear portions 183, 184 of the cut-out 182 being s lightly larger than the sizing of the received the strengthened pla nar support 145 and the received the plana r ta II limit plate 146 and due to the spacing of the strengthened plana r support 145 and the received the planar tall limit plate 146 being slightly la rger tha n the wedge receiver 182 there is some latera l a lignment movement available. When the front and reartrailers 120, 160 are aligned the pivot pin can be fixed between the rigid plate 185 and the pla nar tall limit plate 146. In this way there is lateral locking of the front and rear trailers 120, 160 to prevent substantially a ny pivoting around the vertical axis.

[000107] The further interaction with other combination of parts in a synergistic will now be further described.

WH E E LS

[000108] The wheels are located in three triaxle sets. The wheels of different embodiments can operate in one of the following manners:

a. Manually steered axle

b. S elf-steering axles

c. S elf-steering caster axles

d. Automatically controlled axles

[000109] As shown at the rea r set of wheels of the second trailer in F ig. 4 a pa rticular axle of wheels is steerable sepa rate to the other axles of wheels. However as shown the rear set of three axles (triaxial) mounted at the rear of the front trailer a nd underlying the front of the rear trailer or at the rear of the rear trailer can operate with all three axles of the set of triaxial wheels in operative unison. An axial set of wheels or a set of triaxial wheels can be in a locked steering position or in a n unlocked self-steering position in which position steering is effected by the motion effected by the steering and pulling motion of the prime mover to the trailers.

C ONTR OL

[0001 10] The control of the steering between the lead trailer wheel assembly and the reartrailer wheel assembly can be coordinated with regard to the connection of the front trailer 120 to the prime mover 100. As shown in Figure 18, there is a connection 401 at the front end 24 of the trailer 120, which includes a kingpin 25 at a lower surface thereof for coupling to the fifth wheel coupling 106 of the prime mover 100. C learly when the steering wheels 102 of the prime mover 100 are turned the rea r wheels 134 of the prime mover 100 a re fixed and the front trailer 120 moves relative to the prime mover and respectively the fifth wheel coupling 106 moves relative to the kingpin 25. Comparing Figure 19 to F igure 18 there is shown a relative rotation R R of 60+ of the fifth wheel coupling 106 relative to the kingpin 25.

[0001 1 1 ] The control of the steering makes use of this relative rotation R R of 60+ of the fifth wheel coupling 106 relative to the kingpin 25 of the connection 401 by engaging with a relative steering system 410. This system includes a steering swivel plate 412 adjacent the fifth wheel coupling 106 and having a connecting rod 413 fixedly attached to the swivel plate 412 near one end and pivota lly connected to the fifth wheel coupling 106 at the other end. At opposing ends of the swivel plate 412 are left a nd right steering arms 416, 417.

[0001 12] Therefore, the relative rotation R R of the fifth wheel coupling 106 relative to the kingpin 25 effects swivelling of the swivel plate 413 and relative difference in longitudinal positions of the left a nd right steering arms.

[0001 13] The relative steering system is a ble to take the relative difference in longitudina l positions of right and left steering arm 416, 417 inputs a nd use these to steer the set of wheels 136 at the rear of the front trailer 120 or the set of wheels 138 at the rear of the rear trailer 170.

[0001 14] The transfer from the steering a rm inputs can be by any one of:

a) Mechanical mea ns, such as in Fig 20 which has the right and left steering arms 416, 417 being elongated and mechanically connecting to the steering plate of each axial set of wheels of either the front or rea r triaxial set of wheels 136, 138;

b) Hydraulic means, such as in Fig. 21 which has the right and left steering arms 416, 417 being input to left and right hydraulic lines connecting to the steering plate of each axia l set of wheels of either the front or rear triaxial set of wheels 136, 138; or c) E lectric means, such as shown in Fig. 22 which has the right and left steering arms 416, 417 being input to electrical system directly controlling electric steering motors connecting to the steering plate of each axial set of wheels of either the front or rear triaxial set of wheels 136, 138;

d) Optical such as magic eye;

e) self-steering axles a nd steering locks on the axles which either allow or disallow steering depending upon a logical sequence.

f) Combination of one or more of the above. [0001 15] The steering of each of the set of axial wheels on each set of the triaxial sets of wheels 136, 138 ca n be proportional rather than all three sets of axial wheels turning at the same rate. As shown in F igure 21 at the maximum turn a ngle of the front set of axia l wheels of the triaxial set 136 or 138 can be angle A of 8+ while the second set of axial wheels ca n be a ngle B of 18+ and the third or rear axial set of wheels can be at angle C of 28+. This gives a triaxial set of wheels 136, 138 that readily swings as a set. The angles A, B a nd C can be proportionally va rying up to this maximum a ngle. T he choice of the maximum a ngle is subject to the length of the combination front and rear trailers 120, 170 a nd the swing requirements.

OP E RATION

[0001 16] Referring to F igure 13, when the transport assembly 10 has to perform a turn, such as a left ha nd turn as shown, the front steering wheels 102 of the prime mover 100 pivots to the left (relative to the forwa rd direction), the self-steering axles turn the three wheel assemblies 136a to 136c of the lead trailer 120 also to the left, a nd the self-steering axle of the rea rmost wheel assembly 138c of the rear trailer 160 is pivoted to the right.

[0001 17] F igure 13 is a swept path diagram of the trans port assembly 10 performing a left turn through various positions 201 to 204 and back to 201. As from the above, the coupling assembly 150 substantially locks the A and B trailers 20 a nd 60 together so they ca nnot pivot a bout a vertica l axis, but can pivot a bout a horizonta l axis 37 transverse to the longitudinal length of the trailers such as shown in F igure 3.

[0001 18] The coupling assembly 150 a lso substantia lly prevents the rear trailer 160 from pivoting relative to the lead trailer 120 about a horizontal axis genera lly aligned with the longitudinal length of the lead trailer (substantially prevents ^' twisting _, between the trailers 120 a nd 160). This allows the trailer assembly 10 to carry very long loads. The self-steering axles 138a to 138c at the rear end 26 of the A trailer 120 then allow the transport assembly 10 to turn around corners as required.

[0001 19] In one form of operation with reference to F igure 3, when the transport assembly 10 has to perform a turn, such as a left ha nd turn as shown, the front steering wheels 102 of the prime mover 100 pivots to the left (relative to the forward direction), the self-steering axles turn the three wheel assemblies 136a to 136c of the lead trailer 120 in unison also to the left, and the self-steering axle of one or more of the rearmost wheel assembly 138a, 138b 138c of the rear trailer 160 is pivoted to the right. [000120] In pa rticular with reference to F igure 3, the rear 3 axles 136a, 136b, 136c preferably stay locked until middle 3 axles, 138a, 138b, 138c turn to about 6 degrees. T hen a n electric over air signal is sent to unlock the rear 3 axles and then these follow the middle 3 axles around.

[000121 ] Once back 3 unlock this sends a signa l to lock the middle 3 axles when they return to the centre. This is to be sure that we have control until the back 3 return to lock. Then they dont unlock until centre 3 turn to 6 degrees. And the process starts again. This turning only happens on slow turns. Never on the open highway at speed. On the open highway centre 3 axles remain unlocked, rear 3 locked.

[000122] The operation can be summarised as follows:

[000123] The speed of the slow turn is generally less than 30 kilometres per hour and more preferably less than 20 kilometres per hour. The system is not intended for fast angle cha nges but with a trailer of over 22 metres long and up to 30 metres long the a rrangement is particula rly to allow turning of an articulated long trailer when the carried load can be rigid elongated material such as 22 to 30 metre railway lines extending over both trailers.

[000124] The turn angle at which the locking/unlocking of middle and rear axles occur can be predetermined to suit the particular truck dimensions and usual load length and could be in the range of 4 degrees to 10 degrees deviation from the straight-ahead configuration. P referably it is 6 degrees.

[000125] In a second mode of operation, all three triaxial wheels in a set 136, 138 operate in unison. The swept path diagram of the transport assembly of Figure 1 or F igures 5 and 6, schematically showing the trans port assembly performing a left turn in various positions 201 to 204 a nd back to 201. The triaxial wheels 136, 138 can be self-steering caster axles with locking mechanism.

[000126] Whilst proceeding in a straight line in straight position 201 as shown in Figure 14, the steering wheels 102 of the prime mover 100 and wheels 134 supporting the front trailer 120 are fixed in a facing forward position. The middle set of triaxial wheels 136 has steering unlocked and therefore just follows the prime mover but allows steering as required to minimise turn radius and steer tyre friction. However, for stability and control the rear set of triaxial wheels 138 are locked in a straight position.

[000127] In the commencement of the left-hand turn into position 202 of Figure 15, the steering wheels 102 of the prime mover 100 a re steered left a nd the middle set of triaxial wheels 136 still in the unlocked position are able to follow and self-steer towards a left turn. In the meantime, the rear set of triaxial wheels 138 remain in a straight locked steering position

[000128] In the further progression of the left-ha nd turn into position 203 of Figure 16, the steering wheels 102 of the prime mover a re steered further left a nd the middle set of triaxial wheels 136 still in the unlocked position are able to follow and self-steer towards a left turn. In the meantime, the rear set of triaxial wheels 138 remain in a straight locked steering position. However, when the middle set of triaxial wheels 136 reach a steering angle left which exceeds a predetermined steering limit, the rear set of triaxial wheels 138 have their steering unlocked a llowing the rea r set of triaxial wheels 138 to steer in the opposite direction - which in this case is towards the right. At the same time the middle set of triaxial wheels 136 have re-locked to maintain sta bility. The rear set of triaxial wheels 138 are then able to self-steer in a curved manner to the right to follow the left curve of the middle set of thereby and provide a more effective left turn with a smaller turning a ngle.

[000129] At nearthe completion ofthe left turn a nd in order to straighten up as in position 204 of Figure 17, the steering wheels 102 of the prime mover 100 are directed to the right a nd the middle set of triaxia l wheels 136 follow and steer back to a locked straight-ahead position. The rear set of triaxial wheels 138 are unlocked and follow so that they return to the straight- a head position. Then the rear set of triaxial wheels 138 are locked straight and the middle set of triaxial wheels 136 are unlocked in a self-steering mode. This position is then the starting straight ahead position 201 of F igure 14 ready for a ny further turns.

[000130] Therefore, it ca n be seen that the operation of the sets of triaxial wheels 136 a nd 138 are as follows in the various positions of a turn:

[000131 ] It should be noted that the rear axles do not need to be electrica lly connected to the front trailer or the driver s cabin in order to ensure relative locking a nd unlocking control. Instead there can be markers located underneath such as flags a nd a magic eye or electromagnetic proximity sensor to detect the change of angle of the middle axles or steering rod of the middle axles or wheels attached to the middle axles. When the turn angle is determined remotely by this system at the rear axles then a solenoid can be activated to lock or unlock the rea r axles accordingly. [000132] C learly the present trailer assembly is much more cost effective to build and run for tra nsporting loads of long materia ls than other available systems. The embodiment shows a load of railway lines, however the trailer assembly ca n be used to ca rry a ny long material. T he use of self-steering axles a nd steering locks on the axles which either allow or disa llow steering depending upon a logical sequence is the simplest and most effective method to achieve the desired result. However, there can be other options.

[000133] Referring to Figure 23, when the trailer assembly 10 is not carrying a load, the rear trailer 160 is coupled to the fifth wheel coupling 106 of the prime mover 100 via the central kingpin 65, and the front trailer 120 is loaded onto the rear trailer 160.

OTH E R E MBODIME NTS

[000134] Whilst preferred embodiments of the present invention have been described, it will be a ppa rent to skilled persons that modifications ca n be made to the embodiments described.

[000135] For example, the number of wheel assemblies in the trailers can be increased or decreased as required. Also, the coupling assembly between the lead trailer and the rear trailer can be embodied in other forms.

[000136] For example, the fifth wheel couplings and kingpins can be replaced by two rigid arms, latera lly spaced from each other, rigidly attached to one of the trailers and pivota bly attached to the other trailer. Alternatively, the arms can be pivota bly attached to both the lead trailer and the rear trailer. S uch pivotal attachment ca n be removable for tra nsporting one trailer on top of another if desired.

[000137] Also, both the lead and the rear trailers can be constructed to be res pectively extendable, to a llow the trailer assembly to ca rry longer loads. Also, the rear trailer wheel assemblies ca n alternatively all have manua lly steered axles to assist the trailer assembly in performing turns, or a combination of ma nua lly steered axles and self-steering axles. For example, the rearmost axle ca n be self-steering and the other two can be manually steered.

[000138] S till further in operation of controlling steering of the at least one lead trailer wheel assembly of a multiple axle wheel a nd the at least one rea r trailer wheel assembly of a multiple axle wheel there can be systems which are not dependent upon the locking _, of the self-steering. Other methods to control the steering ca n be a controlling mea ns such as hydraulic cylinders (or pneumatic or electric actuators) attached to the steer axles, a method for measuring the steering angles of some/all of the axles, and a programmable logic circuit (P LC) to control the steering angle of the axle groups relative to each other.

[000139] Alternatively, there can be a mechanical control device which controls the steering of each axie group dependent upon the angle between the prime mover a nd the first trailer.

[000140] It can be seen though that the invention makes use of a steering control means for controlling at least one lead trailerwheel assembly of a multiple axle wheel assembly acting separately or in unison and at least one rear trailer wheel assembly of a multiple axle wheel assembly acting sepa rately or in unison wherein the operation between the lead trailer wheel assembly and the rear trailer wheel assembly is coordinated with the coupling.

[000141 ] For example the steering control means controls steering automatically such that when a turn in a first direction is effected by the steering wheels of a prime mover:

a. initially the supporting wheels of the front trailer are turning in the first direction until reaching a predetermined maximum turning a ngle and while the supporting wheels of the rear trailer are in a straight-ahead position; and b. the ha lting of the turning of the supporting wheels of the front trailer a nd the turning in a second direction being to the opposite side of first direction of the supporting wheels of the rear trailer so that the rear wheels ca n steer in a continuous C- curve or reverse C - curve by the motion effected by the steering a nd pulling motion of the prime mover a nd the front trailer;

c. the straightening and or turning of the steering wheels of the prime mover further switching to effect, by the motion effected by the steering and pulling motion of the prime mover back to a substantia lly straight position of the supporting wheels of the front trailer and the supporting wheels of the rear trailer returning to a straight-ahead position.

[000142] Other embodiments would be understood by a skilled person in the field and a re included within the scope of this invention.

Interpretation

E mbodiments:

[000143] Reference throughout this specification to one embodiment _, or an embodiment _, means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases In one embodiment _, or In an embodiment _, in various places throughout this specification are not necessarily all referring to the same embodiment, but may. F urthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be a pparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[000144] S imilarly it should be a ppreciated that in the above description of example embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features tha n are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than a ll features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description of S pecific E mbodiments are hereby expressly incorporated into this Detailed Description of S pecific E mbodiments, with each claim standing on its own as a sepa rate embodiment of this invention.

[000145] F urthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, a nd form different embodiments, as would be understood by those in the art. For example, in the following claims, a ny of the claimed embodiments can be used in a ny combination.

Different Instances of Objects

[000146] As used herein, unless otherwise specified the use of the ordinal adjectives ^' first., second., ^' third., etc., to describe a common object, merely indicate that different insta nces of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either tempora lly, spatially, in ra nking, or in any other manner.

S pecific Details

[000147] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understa nding of this description.

Terminology

[000148] In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to forthe sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes a ll technical equivalents which operate in a similar manner to accomplis h a simila r technical purpose. Terms such as "forward", "rearward", "radially", "peripherally", "upwa rdly", "downwardly", and the like are used as words of convenience to provide reference points a nd are not to be construed as limiting terms.

Comprising and Including

[000149] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word comprise _, or variations such as comprises . or comprising. are used in a n inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

[000150] Any one of the terms: including or which includes or that includes as used herein is also an open term that also means including at least the elements/features thatfollow the term, but not excluding others. Thus, including is synonymous with and means comprising.

S cope of Invention

[000151 ] Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the a rt will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fa ll within the scope of the invention. For example, any formulas given above are merely representative of procedures that may be used. F unctionality may be added or deleted from the block diagrams a nd operations may be interchanged among functional blocks. Steps may be added or deleted to methods described within the scope of the present invention.

[000152] Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Industrial Applicability

[000153] It is apparent from the above, that the arra ngement described is a pplicable to the trans port industry.