GB2361897A - A vehicle traction and winching arrangement - Google Patents

Abstract

A vehicle traction arrangement in which a controller, which may be part of the normal traction control system of a vehicle, for controlling respective torque drive elements for individual wheels (6, '7) also controls a winch (2) such that a cable (3) secured between a winch motor (8) and an anchor position (5) or another vehicle can be used to facilitate drawing the vehicle towards that anchor (5) or vehicle by selective pull by the winch motor (8) upon the cable (3) and co-ordinated operation of the torque drive elements to drive individual wheels (6, 7) of the vehicle.

Description

2361897 A Vehicle Traction Arrangement The present invention relates to a

vehicle traction arrangement and more particularly to a traction arrangement in which a vehicle incorporates a winch and where individual wheels of a vehicle including the traction arrangement may be independently driven.

It will be understood that vehicles regularly used for so-called off road situations may include a winch in order to aid progress. Furthermore, some vehicles include electronic traction controllers in order to assist progress of a vehicle in an off road environment and also autonomously drive a vehicle when necessary. Such electronic traction controllers may control the torque applied to individual wheels such that each wheel ultimately has independent torque control along with speed and direction control for each wheel. These vehicles can include electrical propulsion or be so-called hybrid electric vehicles in which a heat engine is associated with electrical motors in order to provide propulsion at each wheel. The electronic traction control may also distinctively apply a braking force to each wheel and also a steering angle.

In so-called off road situations as indicated above, it is common to use a winch in order to aid progress. Thus, for example, the winch can be used in conjunction with a fixed anchor to pull or extract the vehicle from a position where vehicle adhesion through the wheels is insufficient to propel the vehicle. Clearly, vehicle terrain adhesion is dependent upon weight,.tyre tread and the nature of the terrain.

The winch can be used in conjunction with driven wheels to assist the vehicle from such a stuck position or the winch can be used to pull objects towards the vehicle e.g. extract a felled log or draw. a boat from the water onto its transport 25 trailer.

However, a limitation with such winches is that if the vehicle is stationary then only the cable length of the winch can be pulled at any one time. Furthermore, if the vehicle is driven whilst the winch is operation, the driver alone is generally not sufficiently skilled to blend the winch pull force smoothly with the driven wheel force in order to optimise traction. Thus, the winch cable may become intermittently slack and therefore not provide any constant traction force with a result of increased winch motor stress etc. It will also be understood that such operation of the winch may cause unnecessary damage to the off road terrain and/or anchor point due to slide and churning as the vehicle wheels attempt to achieve traction etc.

When attempting to winch an object towards a vehicle it is common for the coefficienct of friction or resistance to motion of the object to change during the operation to a point where they exceed that between a vehicles wheels and the ground upon which the vehicle is standing. In such circumstances, a vehicle incorporating the winch may begin to slide towards the object which again, can damage any terrain over which the vehicle is sliding. Such variations in the coefficient of friction of the object may be due to changes in the ground over which the object is pulled e.g. from mud to gravel etc., or possibly, through encounters with resilient objects such as boulders etc. In order to resist this vehicle slide, it is typical to apply an uncontrolled reverse torque to the wheels to counter such vehicle slide movement but unfortunately resulting in further terrain damage.

It is an object of the present invention to provide a vehicle traction arrangement which when incorporated into a vehicle can substantially alleviate the above mentioned problems.

In accordance with the present invention there is provided a vehicle traction arrangement comprising a winch, a controller and wheel traction means, the winch including a cable which may be appropriately anchored at one end to an anchor and pulled at the other by capstan means driven by a winch motor, the wheel traction means comprising torque drive elements associated with individual wheels of a vehicle whereby each individual wheel, or a group of such individual wheels, may be distinctly driven, the winch motor and the torque drive elements being controlled by the controller to co-operate in order to draw a vehicle including the traction arrangement towards the anchor, or vice versa, by selective pull by the winch motor upon the cable through the capstan means and co-ordinated operation of the torque drive elements to drive individual wheels, or a group of individual wheels, of vehicle incorporating the arrangement.

Typically, the controller may be arranged to control selective pull of the cable and co-ordinated operation of the torque drive means without driver intervention. Alternatively, the controller may be arranged to translate a vehicle driver request made through appropriate controls into selective pull of the cable in co-ordinated operation with the torque drive elements as required to achieve that driver request.

The anchor may be secured to or be part of another vehicle such that two vehicles respectively incorporating a traction arrangement in accordance with the present invention can be arranged in series and so act in concert one against the other in order to traverse terrain. Furthermore, the controller may be arranged to selectively apply wheel torque and steering in order to take account of said vehicles being arranged out of alignment whilst associated with each other. 1 The anchor may be secured at an angle to the desired path for a vehicle including the arrangement and the vehicle driven along that path by uneven drive or braking along with steering to individual wheels in order to slew the vehicle into that desired path with propulsion provided both by pulling of the cable and coordinated operation of the torque drive means to the individual wheels.

The anchor may be secured to a mobile object drawn towards the vehicle and the controller arranged to control the winch motor to provide selected pull of the 5 cable and also wheel traction and steering to avoid slip by the vehicle.

The controller may be arranged to ensure cable tension is maintained both whilst a vehicle including the arrangement is propelled up and down an incline by altering the rate of pull by the winch motor controlled by the controller upon the cable and co-ordinated operation of the torque drive elements applied to individual wheels.

The controller may also be associated with brake elements associated with each wheel in order to achieve desired traction of a vehicle incorporating the present traction arrangement.

Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which:Figure 1 is a schematic illustration of a vehicle incorporating the present traction arrangement associated with an anchor through a winch cable in accordance with a first embodiment; Figure 2 is a schematic illustration of two vehicles incorporating the present traction arrangement associated together through a winch cable in accordance with a second embodiment; Figure 3 is a schematic illustration in plan view of a vehicle incorporating the present traction arrangement coupled through a winch cable to an anchor for motion relative to an obstruction in accordance with a third embodiment; Figure 4 is schematic plan view of two vehicles respectively incorporating the present traction arrangements in a mis-aligned configuration in accordance with a fourth embodiment; Figure 5 is a schematic illustration of a vehicle incorporating the present traction arrangement and arranged to traverse a steep incline and decline in accordance with a fifth embodiment; and, Figure 6 is a schematic illustration of a vehicle incorporating the present traction arrange ment and associated with an anchor object which may be drawn towards that vehicle in accordance with a sixth embodiment.

As indicated above, it is known to provide a vehicle with a conventional electronic traction control system and in particular for that traction control system to independently control wheel torque, speed and direction to implement traction control.

In the present invention, the vehicle traction control system has a controller which is integrated with a vehicle winch in order to improve function and performance particularly in extreme road conditions. Traction control systems are particularly common with so-called hybrid vehicles in which a normal heat engine is combined with electrical motors in order to drive a vehicle. In such circumstances, the electrical motors associated typically with each wheel of the vehicle can be independently driven in accordance with the traction control system controller as required in order to propel the vehicle. Such hybrid vehicle configurations are well known to those skilled in the art and can take the form of a series hybrid in which the heat engine generates electrical power which is then supplied to drive individual wheels through torque drive elements or a parallel hybrid configuration in which the heat engine and an electric motor both act upon a propeller shaft which, in turn, provides power to each torque drive element for individual wheels of the vehicle.. It will also be understood through such techniques as regenerative braking, an electrical battery can be used to store and recycle energy in order to facilitate more efficient vehicle operation.

In accordance with a first embodiment of the present invention depicted in 10 Figure 1, a vehicle 1 is associated with a winch 2 which has a cable 3 secured at one end 4 to an anchor 5. The vehicle 1 also incorporates respect torque drive elements associated with individual wheels 6, 7 in order to propel the vehicle 1 either forwards in the direction of arrowhead A or in a reverse direction. The winch 2 through a capstan and winch motor at the end 8 can pun the cable 3 in 15 order to draw the vehicle 1 towards the anchor 5. Thus, the winch 2 and torque drive elements associated with wheels 6, 7 act in co-operation to pull the vehicle 1 towards the post 5. It will be understood that the traction control arrangement in the vehicle 1 operates the respective torque drive elements for each wheel 6, 7 in association with the winch 2 in order to provide through co-operation the most 20 efficient propulsion of the vehicle 1. In such circumstances, a driver of the vehicle 1 will merely indicate through an appropriate control switch, that the controller of the traction control system should operate the winch 2 and torque drive elements in order to cause motion of the vehicle 1 towards the anchor 5. In this first embodiment of the present invention, the driver would then have no further input 25 other than to prevent an eventual collision between the vehicle 1 and the anchor 5. By appropriate control it will therefore be understood that selective pull upon the cable 3 by the winch 2 and co-ordinated operation of the respective torque drive elements associated with wheels 6, 7 will ensure that the traction of the vehicle 1 upon any surface terrain will be maximised in the circumstances. Furthermore, the tension on the cable 3 will be substantially stable and avoid surging and sagging as a result of intermittent traction through varying grip by the wheels 6, 7 upon the terrain whilst the wheels 6, 7 will continue to rotate in a controlled manner such that the vehicle 1 does not slide upon a terrain and so creates less significant furrow and other damage to that terrairL Clearly, and as indicated previously, even the most skilled drivers may find it difficult to balance control between winch 2 operation and torque drive elements in order to maximise traction. Thus, it is preferred that the traction controller acts independently of the driver in order to operate both the winch 2 and the torque drive elements associated with respective wheels 6, 7 for best performance. However, it will understood that alternatively, a driver manual override can be provided whereby the controller acts to translate driver requests into a best combination of winch 2 operation and torque drive element action for each wheel 6, 7 for that driver request. Furthermore, an audio andlor visual indicator may be provided to the driver through the controller in order to allow that driver to operate the vehicle 1 through its normal controls in a condition approximating those ideal to maximise traction of the vehicle 1 towards the anchor 5 without absolute control by the controller over the winch 2 andlor torque drive elements associated with wheels 6, 7.

It will be understood by those skilled in the art that a f=damental requirement of the present traction arrangement is that the controller within the vehicle 1 has a knowledge of the winch 2 for use when required in association with its generally existing knowledge of the torque drive elements normally used to drive the vehicle 1. Thus, the controller will either require initialisation with performance details of the winch 2 or be provided with some means of 8, interrogation of that winch 2 in order to determine its power and rate of pun.

Furthermore, it will be understood that generally through elasticity etc., the action of the cable 3 will depend upon the distance between the winch 2 and the anchor 5 and so in more sophisticated embodiments of the present invention the controller will also be able to determine the length of cable 3 currently extended in order to adjust the pull rate applied through the winch 6 in association with the action of the torque drive elements associated with respective wheels 6, 7 for best traction performance without cable elastic tension release surges.

Figure 2 illustrates a second embodiment of the present invention in which a rear vehicle 11 is essentially towed by a front or forward vehicle 21 with a traction arrangement in accordance with the present invention therebetween. Thus, a winch 22 has a cable 23 secured between an anchor end 24 associated with an anchor surface 25 at the rear of the forward vehicle 21 and a winch end 28 of the winch in which a capstan and winch motor are controlled by a controller of the rear vehicle 11. A controller of the rear vehicle 11 also controls torque drive elements associated with respective wheels 16, 17. Thus, as with the embodiment described with regard to Figure 1, the winch 22 can pull through the cable 23 the rear vehicle 11, in association with the traction efforts from the torque drive elements associated with the wheels 16, 17, towards the forward vehicle 21. The forward vehicle 21 itself is propelled by torque drive elements associated with wheels 26, 27 which engage a terrain surface in order to propel the front vehicle 21 forwards. In such circumstances, it will be appreciated it is the coefficient of friction between the wheels 26, 27 which provide the reaction to allow the winch 22 through the cable 23 to draw the rear vehicle 11 relative to the forward vehicle 21. Thus, it will be appreciated that the points of contact of the vehicles 11, 21 are defined by the engagement between the wheels 16, 17; 26, 27 with the terrain surface over which the vehicles 11, 21 are driven.

9_ It is a fundamental premise of ofT road driving technique that the more available driven wheel contacts with the terrain surface there are then the greater the possibility of efficient propulsion of that vehicle. Thus, in the situation depicted in Figure 2, it will be appreciated that an effective convoy of vehicles 11, 21 broadens the potential for driveable engagement between one or more of the wheels 16, 17; 26, 27 with the surface terrain so that a convoy of vehicles 11, 21 can progress over that terrain surface. The winch 22 and connecting coupling thereby provide a tractive connection between the vehicles 11, 21.

In the second embodiment depicted in Figure 2, it will be understood that generally a single controller located in one or other of the vehicles 11, 21 will control all torque drive elements associated with wheels 16, 17; 26, 27 and also the winch 22 in order to maximise the traction effort of all the torque drive elements 1 associated with the wheels 16, 17; 26, 27 and winch 22 through connecting cable 23. In such circumstances, it will be appreciated that in irregular terrain in terms 15of varying coefficient of friction between the wheels 16, 17; 26, 27 it will possible for the vehicle to vary the spacing as provided by the cable 23 using the winch 22 to maximise collective traction and so avoid stop/start operation. For example, 1 when fording a river it will be noted that the river may have intermittent mud, silt, shingle and rock as the river bed such that a first forward vehicle 21 may cross unreliable portions of the river bed but disturb that river bed for subsequent vehicles, but in accordance with the present invention, the forward vehicle 21 when engaged with a more reliable higher coefficient of friction portion of the riverbed will be able to assist movement of the rear vehicle 11 through the winch 21 reaction against the anchor position 24 at the rear of the forward vehicle 21 in more robust engagement with the river bed or bank. The provision of the winch 22 within the present vehicle traction arrangement allows maximisation of the collective tractive effort of the torque drive elements associated with wheels 26, 27, 16, 17 and winch 22.

It will be understood by those skilled in the art that reliable anchor points may not be conveniently located relative to a vehicle position for desired vehicle paths. Thus, as depicted in Figure 3 in a third embodiment of the present invention, a vehicle 31 incorporates a traction arrangement with a controller which controls the torque drive elements associated with wheels 36-40 and a winch 32 through a capstan/winch motor associated with a winch cable 33. The winch cable 33 is secured at an anchor end 34 to an anchor 35 and at a winch end to the capstan/winch motor controlled by the controller.

In the embodiment depicted in Figure 3, an obstacle 30 is located about the vehicle 31 and the anchor 35 is at an angle relative to a desired vehicle travel path indicated by arrowhead B. Thus, in accordance with the present invention in order to propel the vehicle 31 in the direction of arrowhead B the controller acts to pull the cable 33 towards the winch end 38 through activation of the capstan and winch motor whilst the respective torque drive elements associated with wheels 36-40 are independently controlled and steered in order to slew the vehicle 31 against the natural pull towards the anchor 35 and so collision with the obstacle 30.

Clearly, in such circumstances, the wheels 36-40 will be turned away from the obstacle 30 and the torque drive el ements associated with wheels 36, 37 will be driven faster than the torque drive elements associated with wheels 39, 40 to again facilitate slew steering of the vehicle 30 away from collision with the obstacle 30. This obstacle avoidance is possible by causing the vehicle as described to slew to the desired path (arrowhead B). Such slewing as indicated is implemented by biasing the torque to one side of the vehicle to olfset the steering effect whilst the winch is pulled to move. the vehicle 31 by a vector component in a straight line in the direction of arrowhead B. It will also be understood a braking i 1 f force could be applied to specific wheels i.e., 39, 40 using the controller to further facilitate steering away from the obstacle 30. Finally, the controller itself may precipitate the steering of the wheels away from the obstacle 30.

An extension of the principal of operation described with regard to the third embodiment of the present invention above is depicted in Figure 4 as a fourth embodiment of the invention. It will be understood that where a forward vehicle 41 tows a rear vehicle 42 it is possible particularly in off road situations for the vehicles to assume an offset towing or pulling condition as depicted in Figure 4. Thus, a controller associated with the vehicles 41, 42 acts to control the torque drive elements associated with the respective wheels of the vehicles 41, 42 and also a winch 43 having a cable 44 between the vehicles 41, 42. In such circumstances, as described above with regard to Figure. 3, the controller will act through selective operation of the torque drive elements associated with the wheels of the respective vehicles 41, 42 in order to both propel and steer the vehicles 41, 42 along their respective drive paths C, D. Furthermore, as described with regard to Figure 2, the increased number of terrain surface engagements through the respective wheels of the vehicles 41, 42 will increase potential for good contact with a proportion of that terrain surface to enable not only propulsion by that wheel into engagement but also reaction between the vehicles 41, 42 in order to allow the cable 41 when appropriately drawn in by a capstan/winch motor under the control of the controller to facilitate enhanced collective traction effort between the vehicles 41, 42.

Clearly, the vehicles 41, 42 can be brought back into alignment when desired where the controller associated with the vehicles 41, 42 and when terr configuration allows. However, it will also be understood that particularly when traversing sandy terrain where the first vehicle may disturb the surface of that terrain an askewed or offset towing configuration as depicted in Figure 4 may be preferred in order to maximise the traction reaction of the wheels driven by the torque drive elements upon disturbed terrain surfaces.

If a winch cable is subjected to varying tensions, it will appreciated that there is a greater potential for failure both of the cable and the winch arrangement as a result of cyclic factors. In a fifth embodiment of the present invention depicted in Figure 5, it will be noted a vehicle 51 is arranged to ascend a steep incline using the propulsive power of torque drive elements associated with respective wheels 56, 57 and a winch 52 through a cable 53 secured at one end 54 to an anchor 55 and at the other end to a capstan/winch motor 58 associated with the vehicle 51.

It will be appreciated on the ascent the cable 53 will be subject to varying tension as the tractive effort provided through the wheels 56, 57 alters whilst the cable 53 1 may become slack as the vehicle runs away in descent.

In accordance with the present invention, the controller arranged to control the torque drive elements associated with the wheels 56, 57 and the capstan/winch motor drawing the cable 53 is arranged such that the tension in the cable 53 is substantially maintained by varying the pull rate through the winch motor 58 dependent upon the tractive effort provided by the torque drive elements through the wheels 56, 57 and the angle of ascent of the vehicle 51. Alternatively, when in descent the tension in the cable 53 will be signfficantly reduced and thus in order to maintain any tension in the cable 53 and also control such vehicle 51 during such descent it will appreciated that the torque drive elements associated with wheel 56, 57 may be driven in a reverse direction against the natural tendency of the vehicle 51 to run away or slide down the decline. Thus, the controller associated with the winch 52 and torque drive elements of the wheels 56, 57 ensures that there is a consistent operation of the vehicle 51 during ascent and descent. Essentially, the vehicle co-ordinates the application of tractive and/or braking forces to maintain a constant winch draw rate and so tension in the cable 53. When going uphill the vehicle will be provided with suitable tractive torque through the wheels 56, 57 and assisted by winch draw of the cable 53 whilst during descent braking torque and/or braking effort will be applied to the wheels 56, 57 through a descent control arrangement in order to maintain control of that vehicle 51 during both ascent and descent of respective inclines.

As indicated previously, a winch associated with a vehicle in an off road environment may also be used in order to pull an object towards that vehicle. However, inherently it is the friction and resistance to motion between the vehicle and in particular the vehicle wheels and a surface terrain which defines the reaction against which the winch acts in order to draw the object towards the vehicle. In such circumstances, as depicted in Figure 6 is a sixth embodiment of the present invention, a vehicle 61 includes a controller arranged to control both a winch 62 and respective torque drive elements for wheels 66, 67 of a vehicle 61. The winch 62 includes a cable 63 with one end secured at an anchor position 64 associated with an object 65 to be drawn towards a vehicle 61 and another end of the cable 63 secured to a capstan/winch motor 68 in order to pull the cable towards the vehicle 61.

Generally, where the vehicle 61 through its weight or other means is substantially fixed through a sufficient coefficient of friction upon a surface terrain relative to that of the object 65 then that object 65 will be drawn by the action of the cable 63 relative to the capstan/winch motor 68 towards the vehicle 61. However, where the object 65 engages either an obstruction or through its weight/coefficient of friction upon the surface assumes a position where there is greater resistance by the object 65 upon the surface terrain than there is resistance by the vehicle 61 on its own terrain then the vehicle 61 may be pulled towards the object rather than vice versa-. Clearly, this is not an acceptable situation. Thus, in accordance with the present invention the controller acts to determine when such movement of the vehicle 61 rather than the object 65 is about to occur. The controller then adjusts the pull rate through the winch 62 and provides a reverse propulsion through the torque drive elements for wheels 66,67 to again exceed the resistance of the object 65 at that position to continue drawing the object 65 towards the vehicle 61 position.

It will be understood that if the object 65 engages an obstacle which cannot be readily overcome then the controller will cease to draw the object 65 towards the vehicle 61 and provide a warning to an operator of the vehicle 61 in order that the cause of such fouling of the object 65 can be determined and cleared.

Generally, the controller will the monitor the speed of the wheels to detect if the winched object 65 is causing the vehicle 61 to loose its engagement with the terrain surface. Thus, at the moment when such grip is about to be lost it may be possible to provide simply additional braking effort in order to resist vehicle 61 movement towards the object rather than vice. versa. However, it will normally be required to provide additional controlled reverse torque through the drive elements associated with the wheels 66, 67 in order to counter movement of the vehicle relative to the object rather than vice versa.

It is known that maximum wheel traction can be obtained with a degree of wheel slip thus, if the winch 62 is pulling an object and the vehicle applied torque against the movement of the vehicle were to initially induce wheel slip then a greater pulling effort may be exerted than through a static vehicle with simply braked wheels 66, 67. In any event, where the object for example is a log or boat to be extracted from a wood or lake it will be appreciated that the vehicle 61 position must be substantially maintained otherwise that vehicle 61 may be pulled into the wood or lake rather then the log or boat extracted.

It will be appreciated that a winch can be provided at either end of a vehicle in accordance with the present invention and thus a convoy of vehicles as depicted in embodiments 2 and 4 of the present invention can be provided in order to maximise the combined tractive effort of all vehicles in such a convoy across 5 uneven terrain.

The above description is for example only. Furthermore, it will be appreciated that generally four wheels will be provided so that where two are depicted in the drawings normally there will be an opposing pair of wheel so the other side of the vehicle which may act, in terms of torque drive element operation, either independently of those depicted or as a co-ordinated group of wheels with those depicted or together or otherwise.

i t 1

Claims (10)

1. -16CLAIMS

   A vehicle traction arrangement comprising a winch, a controller and vehicle traction means, the winch including a 'cable which may be appropriately anchored at one end to an anchor and pulled at the other end by a capstan means driven by a winch motor, the wheel traction means comprising torque drive elements associated with individual wheels of a vehicle whereby each individual wheel, or a group of such individual wheels, may be distinctively driven, the winch motor and torque drive elements being controlled by the controller to co-operate in order to draw a vehicle including the traction arrangement towards the anchor, or vice versa, by selective pull by the winch motor upon the cable and coordinated operation of the torque drive elements to drive individual wheels, or a group of individual wheels, of a vehicle including the arrangement.
2. 2. An arrangement as claimed in Claim 1 wherein a controller operates independently in order to determine and maximise tractive eflort by cooperation between the winch and the respective torque drive elements without specific vehicle driver intervention.
3. 3. An arrangement as claimed in Claim 1 wherein the controller is arranged to control the winch and the torque drive elements by translating specific vehicle driver request s to requirements for selective pull by the winch motor upon the cable and associated co-ordinated operation of the respective torque drive elements for each individual wheel.
4. 4. An arrangement as claimed in any of Claims 1,2 or 3 wherein the anchor is secured to another vehicle in a series.
5. 5. An arrangement as claimed in Claim 4 wherein the respective vehicles incorporating a vehicle traction arrangement are arranged through selective pull upon the cable therebetween and co-ordinated operation of torque drive elements to assume respective directions of travel which are off-set relative to each other.
6. 6. An arrangement as claimed in any preceding claim wherein the anchor is secured at an angle relative to the desired path for a vehicle including the arrangement and the vehicle including the arrangement is driven along that path by uneven operation of the respective torque drive elements to individual wheels andlor braking thereof in order to slew the vehicle into that desired path as compared to the natural tendency of the vehicle to be drawn towards the anchor by the pull upon the cable by the capstan means.
7. 7. An arrangement as claimed in any preceding claim wherein the anchor is secured to a mobile object and that object is drawn towards the vehicle under the control of the controller such that variations in the resistance to motion of the mobile object relative to a vehicle incorporating a vehicle traction arrangement does not result in the vehicle position being substantially altered in that the vehicle is drawn towards the object rather than the object drawn to the vehicle.
8. 8. An arrangement as claimed in any preceding claim wherein the controller 1 - is arranged to ensure that cable tension is maintained when a vehicle is drawn up an incline as compared to descending a decline by specific alteration in the rate of selective pull by the winch motor and the torque applied to each individual wheel by its respective torque drive element.
9. 9. A vehicle traction arrangement substantially as hereinbefore described with reference to Figure 1 or Figure 2 or Figure 3 or Figure 4 or Figure 5 or Figure 6.
10. 10. A vehicle incorporating a vehicle traction arrangement as cLqimed in any preceding cl.

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