EP0453494A1

EP0453494A1 - A vehicle

Info

Publication number: EP0453494A1
Application number: EP19900902299
Authority: EP
Inventors: David Dowler; Laurence George Watts; David John Wilson
Original assignee: DOWLER GANTRY SYSTEMS Ltd
Current assignee: DOWLER GANTRY SYSTEMS Ltd
Priority date: 1989-01-11
Filing date: 1990-01-11
Publication date: 1991-10-30
Also published as: CA2045118A1; WO1990007866A2; WO1990007866A3; AU4957590A

Abstract

Le véhicule comprend une section allongée (11) possédant des sections de châssis (12, 13) à ses extrémités. Les sections de châssis portent respectivement des roues d'entraînement (17, 21) et des roues supplémentaires (22, 27). Les roues (17, 21) peuvent être entraînées de façon â permettre au véhicule de se déplacer transversalement ou longitudinalement par rapport à lui-même le long d'un champ ou d'une route respectivement. La section allongée (11) peut être remontée ou abaissée par des vérins d'ajustement (55) par rapport aux sections de châssis. Par ailleurs, lorsqu'on déplace le véhicule dans le sens longitudinal, une roue avant orientable (17) et une roue arrière orientable (21) peuvent être commandées de façon à ce que l'on puisse orienter la roue arrière seulement après avoir orienté la roue avant selon un angle donné.The vehicle includes an elongated section (11) having chassis sections (12, 13) at its ends. The chassis sections respectively carry drive wheels (17, 21) and additional wheels (22, 27). The wheels (17, 21) can be driven so as to allow the vehicle to move transversely or longitudinally relative to itself along a field or a road respectively. The elongated section (11) can be raised or lowered by adjustment cylinders (55) relative to the chassis sections. Furthermore, when the vehicle is moved in the longitudinal direction, a steerable front wheel (17) and a steerable rear wheel (21) can be controlled so that the rear wheel can be steered only after the front wheel at a given angle.

Description

A VEHICLE

The invention relates to a vehicle and is particularly, but not exclusively, concerned with improvements in a vehicle described in GB-A-1578857.

In GB-A-1578857 there is described an agricultural vehicle including an elongate structure having at least one ground wheel carried at each end of the structure. The height of an elongate section of the structure can be adjusted only by bolting it at different vertical positions to end sections of structure on which the wheels are mounted and one object of the present invention is to provide an improved method of enabling the position of the elongate section of the structure above the ground to be varied.

According to a first aspect of the invention there is provided a vehicle comprising a structure including an elongate section, at least one wheel carried by a further section of the structure adjacent each end of the elongate section, drive means for driving the vehicle in a direction transverse to or longitudinally of the structure, and a height adjustment device arranged to lift or lower the elongate section of the structure relative to the further sections. The height adjustment device gives the vehicle considerable flexibility. It assists in the attachment of implements to the vehicle and, by use of the beam in its highest position, allows implements to be carried at a safe height above the ground when not in use e.g., driving along a road. The height adjustment device is also of particular use when the vehicle is used for agricultural purposes allowing the height of the elongate section to be adjusted according to the height of the crop.

Preferably, each end of the elongate section is connected to the further section by guide means which permits said height adjustment, and the guide means may comprise an upwardly extending rail.

Ideally, the rail forms a guide for a member movable therealong, the rail being connected to one of the associated further and elongate sections -and the member being connected to the other of the associated further and elongate sections. The rail may be channel cross-sectional shape.

Where the said member is provided which is movable along the rail, the member may be positioned in the channel. Preferably two spaced apart channel shaped rails are provided with respective members positioned thereon. The elongate section may be connected to at least one of the further sections through an intermediate section, but preferably the elongate section is connected to both further sections through respective intermediate sections. These intermediate sections provide an adaptor between the further sections on which the drive means is mounted and the elongate section, and conveniently the or each intermediate section may be connected to its associated further section by said guide means.

The height adjustment device may be in the form of a fluid operable ram or other actuator, which may be attached between first and second points on the structure. The actuator may be arranged to raise the elongate section from a lower position to a higher intermediate position at which it can be retained, the actuator then being arranged to attach between said first point and a third point of the structure to enable the elongate section to be raised to its highest position. The latter arrangement is particularly useful as a ram can be used having a stroke which is very much shorter than the total distance between the lowest and highest positions of the elongate section. Preferably the second and third points are provided on a common member. In GB-A-578,857 the structure includes a lattice like elongate main section attached to wheel mounting frame sections which is satisfactory in many ways but presents complications in manufacture. Another object of the present invention is to provide a vehicle having an improved form of elongate section.

According to a second aspect of the invention there is provided a vehicle comprising an elongate structure, at least one wheel carried at each end of the structure and drive means for driving the vehicle in the direction transverse to or longitudinally of the structure, the structure including a main section of tubular form.

Such a main section is considerably easier to manufacture than the lat ice-like structure in GB-A- 1578857, and also permits greater flexibility for the mounting of tools.

The main section may form a hollow frame which preferably surrounds conduit associated with fluid circuitry of the vehicle. This is particularly useful as it provides improved protection for the hydraulic pipe-work, whereas in GB-A-1578857 the open structure of the lattice-like part of the frame left the conduit exposed. Preferably, the main section is of polygonal cross- section, e.g., hexagonal, and may be formed from two half polygonal sections connected together. The half polygonal sections may form upper and lower portions of the main section. Conveniently, each section may have edge flanges which extend transversely and which form means enabling the polygonal halves to be bolted together.

Torsional stiffness of such a main section can be made greater than the lattice-like part of the frame of GB-A-1578857 which is highly desirable particularly when carrying a full tank of spray liquid at one end of the structure.

According to a third aspect of the invention there is provided a vehicle comprising a structure including an elongate section, at least one wheel carried by a further section of the structure adjacent- each end thereof, drive means for driving the vehicle in a direction transverse to or longitudinally of the structure, at least one end of the main section including fillets which enable the elongate main section to be connected to the adjacent further section.

Such fillets may also be provided in a vehicle according to said first or second aspect of the invention or any of the consistory clauses dependent thereon.

The fillets may conveniently extend along peripheral portions of the elongate section so as to provide reinforcement. This provides a particularly strong connection between the aforementioned sections.

According to a fourth aspect of the invention, there is provided a vehicle comprising a structure including an elongate section, at least one wheel carried by a further section of the structure adjacent each end thereof, and drive means for driving the vehicle in a direction transverse to or longitudinally of the structure at least one of the further sections including a mounting on which a cab is supported.

Such a cab may be provided in a vehicle according to said first, second or third aspects of the invention or any of the consistory clauses dependent thereon.

The further section carrying the cab may include a surrounding member mounted on the further section and which extends around at least part of the cab to form, e.g., a fender. The cab surrounding member may extend beneath the cab and may have thereon resilient mounting means for the cab. The resilient mounting means provides a non-rigid interconnection between the cab and the further section so as to damp out vibration and improve driver comfort. Two surrounding members may be provided extending adjacent from and rear sections, e.g., a container thereon.

Each aforesaid further section may include a pivotal mounting for one of the steerable wheels.

Each further section may be provided with a mounting for a further wheel e.g., a castor-like wheel which is preferably aligned with the steerable wheel when the vehicle is being driven in the direction transverse to the structure. In that respect, the arrangement is somewhat similar to that described in GB-A-1578857.

Preferably, the castor-like wheel is mounted on an arm which may be raised and lowered relative to the further section. In that way, fine height adjustment of the structure relative to the ground may be achieved.

Preferably, the two further sections are substantially identical. The other further section may be used to carry a container such as a reservoir for liquid to be sprayed by the vehicle. Conveniently, a motor or engine housing may be provided between at least one further section and the adjacent end of the elongate section, and preferably one engine drives the vehicle.

Where a cab is provided on one of the further sections, it is preferable that the housing for the engine is arranged adjacent the further section on which the cab is mounted. In that way, engine control linkages or the like from the cab to the engine can be kept as short as possible. Where said intermediate member is provided, the housing may be formed by said member.

As mentioned above, the vehicle described in GB-A- 1578857 includes an elongate structure having at least one ground wheel carried at each end of the structure. The wheels enable the implement to be steered when being driven in the longitudinal direction of the frame e.g., along a road. Steering is effected by turning each wheel simultaneously by means of a common steering wheel and hydraulic circuitry. Such steering tends to cause the trailing end of the vehicle to swing to one side or the other during steering and such steering may be disadvantageous in certain instances. For example, when travelling around a- fairly shallow curve, simultaneous steering of the front and rear wheels can cause the rear end of the implement to swing towards the centre of the road away from the kerb which may be undesirable. Another object of the present invention is to provide an improved steering arrangement in such a vehicle.

According to a fifth aspect of the invention, there is provided a vehicle comprising an elongate structure, at least one wheel carried at each end of the structure, drive means for driving the vehicle in a direction transverse to or longitudinally of the structure, steering means for steering the wheels when the vehicle is travelling in the direction longitudinally of the structure, and control means which enables the steering means to steer one of the wheels after the other has been steered by a pre¬ determined amount.

Such an arrangement is particularly useful as the rear wheel can be arranged so as not to steer when travelling around shallow curves and so the above disadvantage is avoided.

In a preferred arrangement, the said control means may enable the other wheel to be steered up to around 10 degrees without steering movement being applied to the said one wheel. Preferably, the said control means also enables the wheels to be steered independently of each other or simultaneously. It will be appreciated that such an arrangement provides complete versatility and, therefore, is highly advantageous. Conveniently, the selection of various steering modes of the vehicle can be effected from a cab on the vehicle.

In order to mount apparatus such as a spray boom or a soil tilling tool on the elongate structure a linkage may be provided and, according to a sixth aspect of the invention, there is provided a vehicle comprising a structure including an elongate section, having at least one wheel carried by a further section of the structure at each end thereof, and drive means for driving the vehicle in a direction transverse to or longitudinally of the structure, the elongate section providing or defining support means for first and second linkages on opposite sides of the elongate section, each linkage including pivotally interconnected arms by means of which apparatus can be connected to the vehicle, each linkage including actuator means for causing the arms to move so that a ool carried by one or each of the linkages can be moved from an operative position to a stowed position. Preferably, the or each actuator means is operable independent1y.

Conveniently, each linkage is arranged to move its tool from a position which is lower than at least part of the support means in its operative position to a stowed position well clear of the ground. Attachment means on the linkage for its tool may be positioned generally adjacent the support means when in the stowed position or may engage the support means.

Linkages may be arranged on the support means at spaced positions therealong.

Preferably, two pairs of linkages are provided on opposite sides of the elongate section interconnected by support members and a tool carried by each pair.

Wheels of the vehicle are drivable to effect movement of the vehicle and may be contained in hollow wheel mountings to provide protection for conduit carrying driving fluid for the wheels.

Ideally, control means may be provided whereby the drivable wheels cannot be driven at relative speeds when the vehicle is travelling longitudinally of the elongate structure. This ensures that there is no scrubbing of a wheel on the ground due to the wheels turning at different speeds when the vehicle is being driven along the road in a longitudinal direction. The control means therefore, may provide a "Field Mode" or a "Road Mode" for a fluid drive to the wheels.

The elongate structure provides an ideal mounting for a tool such as a spray boom and enables spray to be deposited extremely accurately over the area being sprayed.

Preferably, the elongate structure is arranged to support a tool or implement substantially in the form of a boom, which may be extensible up to or beyond the ends of the vehicle. Bearing in mind the length of the structure there will be little in the way of up and down movement of the extreme ends of the spray boom extensions, thereby ensuring accurate deposit of spray even at the extreme ends of the extension.

Conveniently_A the boom is extensible by providing an extension part pivotally connected to a main boom part and which can be moved from a stowed position alongside the main boom to a position extending longitudinally therefrom. Preferably, the extension includes a second extension part which is movable from a stowed position alongside or overlying the first extension part which is movable into an extended position extending longitudinally of the first extension part. A third extension part may be connected to one end of the second extension part for movement into its extended position.

Preferably, the first extension part pivots about a substantially vertical axis into its extended position. Where the third extension part is provided, the third extension part may be pivotally connected to the second extension part which extends generally horizontally transverse to the elongate structure.

The second or, where provided the third boom extension part may comprise two parts which are held in end-to-end abutment by means of a resilient interconnection. The resilient interconnection preferably allows said parts to be articulated relative to each other. Such an arrangement is highly advantageous in that where the extended boom strikes a. rigid object such as a tree or post, the boom will "break" at the abutment to reduce the likelihood of damage to the extended boom.

Preferably, the abutment between the two parts comprises horizontally spaced apart abutments on one of the parts which locate in sockets or the like in the other of the parts. Articulation of the parts causes this pivotal movement to take place about one of the pivot/socket abutments so as to separate the other socket and abutment against the bias of the resilient interconnection.

Preferably, each end of the spray boom is provided with an extension arrangement, in which the first, second and third extensions, when in stowed positions are arranged alongside the main boom and conveniently, the extensions in their stowed position occupy no more than half the length of the main boom section.

According to a seventh aspect of the invention there is provided a linkage connecting a tool to an agricultural vehicle comprising a first arm pivotally connected to a support means of the vehicle, a second arm for. carrying the tool and being pivotally connected to the first arm intermediate its ends, a third arm pivotally connected to the second arm at a point spaced from the pivotal connection to the first arm and which is pivotally connected at its other end to the support means of a member connected thereto, and actuator means for pivoting at least one said arm whereby the tool can be moved from an operative position adjacent the ground to a stowed position clear of the ground. Preferably, the tool is carried at an end of the second arm spaced from the connection between the second arm and third arm, and the third arm may be pivotally connected to the support means above the pivotal connection between the first arm and the support means.

Preferably, one end of the actuator means is pivotally connected to the support means, and the other end of said actuator means may be pivotally connected to the first arm.

Conveniently, the actuator may be pivotally connected to the first arm at a position to one side or to the other side of the pivotal connection between the first arm and the support means. The third arm may cross the first arm when viewed in a direction axially of the pivotal connections.

Such a geometrical arrangement of linkage allows the tool attached to the linkage to be moved through a large arc from its position in use to its stowed position for a relatively small stroke of the actuator means.

The features of the linkage as set out in the seventh aspect of the invention or any of the consistory clauses relating thereto may also apply to the vehicle of the sixth aspect of the invention.

A vehicle in accordance with the invention will now be described by way of example with reference to the accompanying drawings in which:-

Fig.1 is an elevation of a preferred form of vehicle in accordance with the invention.

Fig.2 is an end elevation of a container end of the vehicle shown in Fig.1,

Fig.3 is an end elevation of a cab end of the vehicle shown in Fig. ,

Fig.4 is a plan view of the vehicle shown in Fig.1,

Fig.5 is an elevation of part of one end of tiie vehicle shown partly in cross section,

Fig.6 is a plan view of the end part of the vehicle shown in Fig.5,

Fig.7 is a cross section on the line VII-VII in Fig.5,

Fig.8 is a cross section through an elongate section of the vehicle shown in Fig.1 on the line VII-VII in Fig.1 ,

Fig.9 is a cross section of the vehicle shown in Fig.1 on line IX-IX in Fig.1 showing a height adjustment ram for the elongate section at its lowest position,

Figs.10 and 11 are views of part of the arrangement shown in Fig.9 with the ram in respective intermediate and highest positions,

Fig.12 is a schematic diagram of the control means for driving the vehicle,

Fig.13 is a schematic diagram showing the part of the control means for co-ordinated steering when driving longitudinally of the structure,

Fig.14 is a cross section through the elongate section of the vehicle showing tool mounting linkages thereon,

Fig.15 is a plan view of part of one of the linkages shown in Fig.14,

Fig.16 is a diagrammatic perspective view of an extension arrangement for a spray boom, Fig.17 is a diagrammatic plan view of the vehicle showing the position of the extensions relative to the vehicle.

With reference to Fig.1, the vehicle comprises an elongate structure 10 comprising a main frame section 11 (constituting the aforesaid elongate section) connected to chassis sections 12, 13 through intermediate sections 14, 15. The chassis sections constitute the aforesaid further sections.

The elongate section 11 can be arranged to carry various types of tools (which term includes implements, sprayers, spreaders and the like) as will be described below.

The chassis section 12 of the structure 10 carries a steerable drive wheel 17 which is driven by means of a hydraulic motor 17a adjacent the hub of the wheel, the wheel being mounted on a mounting unit 18 having mounting flanges 19 at its upper end pivotally supported for movement about a vertical axis on a mounting 20 of the chassis section 12. The chassis section 12 also carries a freely rotatable castor- wheel 22 on a parallelogram linkage 23 (Fig.3). The vertical position of the linkage 23 can be varied by means of an adjustable ram 24. The castor wheel 22 is pivotable about a vertical axis 25 defined by the linkage 23.

The chassis section 13 carries a drive wheel 21 on a mounting unit 26 in exactly the same way as the chassis unit 12. The wheel is drivable by means of a hydraulic motor 21a adajcent the hub of the wheel. The chassis unit 13 also carries a castor wheel 27 which is mounted on a parallelogram linkage in the same way as castor wheel 22.

In the present invention a switching arrangement is provided as shown in Fig.12 to switch the steering from road mode to field mode operation.

The elongate section 11 comprises a hexagonal cross- section tubular frame formed from pressed metal sheet or plate. The elongate section includes upper half hexagon section 28 and a lower half hexagon section 29 which are bolted together through edge fianges 28a, 29a. As shown in Fig.8, internal webs 30 are provided for stiffening purposes and are formed with cut outs 32 to allow hydraulic pipework 33 to run along the inside of the main section from one end to the other. Each end of the main section is provided with external upper side stiffening members 34, a top stiffening member 35 and a two lower side stiffening members 36 (see Figs.5 and 8). The stiffening members (constituting the aforesaid fillets) and the ends of the elongate section 11 are connected to end plates 37 by means of bolts 38 which pass through flanges 38a on the stiffening members, through the end plates 37 and through inclined frame members 39 of the intermediate sections 14, 15. The elongate section is also connected to the intermediate sections by means of further bolts 40 which pass through the flanges 40a on the lower stiffening members 36, through the end plate 37 and through webs 42 extending between the inclined frame members 39.

The frame members 39 are connected at their upper ends to upper frame members 43 and at their lower ends to lower frame members 44. The lower ends of frame members 39 are interconnected by means of a frame member 45, the frame members 43 are connected at their right-hand ends as viewed in Figs.5 and 6 to a cross member 46 and the right-hand ends of frame members 44 are connected to a cross-member 47. The right-hand ends of frame members 44 are connected to the right-hand ends of the frame members 43 directly above by means of vertical slide members 48. The slide members 48 are slidably located in vertical rails in the form of channel section slideways 49 of the adjacent chassis section. The upper ends of the slideways 49 (constituting the aforesaid guide means) are joined together by a connector piece 50 and, as shown clearly in Fig.4, two fenders 52, 53 extend from the upper ends of the slideways 49, and bend around to form vertical sections 52a, 53a, and lower horizontal sections 52b, 53b. The lower horizontal sections are connected to a chassis members 51 on which the slideways 49 are mounted. The chassis members 51 carries the wheel mountings 20 and the parallelogram linkage 23.

The lower sections 52b, 53b of the fenders 52, 53 are provided with resilient mounting pads 54 on which a cab 60 is mounted. The cab 60, is, therefore, resiliently mounted on the chassis section 12 and vibrations are damped by the pads. The cab may be of monocoque construction with a door 6 pvitoable about a vertical axis.

The intermediate sections 14, 15 are substantially identical. The elongate section 11 is joined to the intermediate section 15 in the same way as it connects to intermediate section 14. The intermediate sections can be raised and lowered along the respective slideways 49 provided on the respective chassis sections 12, 13 by means of respective hydraulic ram 55. The cylinder of each hydraulic ram 55 is connected to the cross member 46 and the remote end of the piston rod 55a of the ram is connected to a removable connecting pin 56 mounted on a vertical channel 57 on the chassis section.

The connecting pin 56 has two connecting positions 56a, 56b for the piston rod of the ram 55. The positions are vertically spaced apart as apparent from Figs.10 and 11.

To raise the intermediate sections 14, 15, fluid is fed simultaneously to the upper end of each ram 55 so as to cause the cylinders to move upwardly taking with them the cross members 46 and hence the intermediate sections. The stroke of the ram is insufficient to raise the intermediate sections for the full length of the slideways 49. Once the first stroke of each ram has been completed to raise the intermediate sections to higher intermediate positions, the sections are locked in position by means of suitable locking members 59 associated with the slideways 49. The piston rod of each ram 55 is then detached from the attachment point 56a and then retracted into the cylinder and re-attached to point 56b. Fluid is then fed to the rams again to raise the cylinders, and hence the intermediate units to the full extent of their vertical travel, the locking members 59 first being removed.

Suitable retention means (not shown) may be provided for retaining the intermediate members in any position so that fluid pressure on the rams can be relieved.

The fenders 52, 53 protect corners of the cab against, e.g., branches. The opposite chassis section 13 also has identical fenders 52, 53 to make the chassis section 13 substantially identical with the chassis section 12. The chassis section 13 may be arranged to carry a container 61 for spray fluid.

The intermediate section 14 preferably houses a motor 170 for driving the hydraulics of the vehicle and the intermediate section 15 may be used to house a pump for pumping fluid from the reservoir 61 to spraying apparatus.

The vehicle can be driven in the same way as the vehicle described in GB-A-1578857 i.e., either transverse to or longitudinally of the elongate structure 10. When driving in the transverse direction (herein called the field mode), the vehicle is driven by the hydraulic motors 17a, 21a and can be steered by varying the relative speeds of the wheels 17, 21. To drive the vehicle in the longitudinal direction (herein called the road mode) the wheels, 17, 21 are turned through 90 degrees by means of hydraulic rams 68, 69 (Figs.12 and 13) so as to lie in line with each other parallel with the elongate section 11. The wheels, 17, 21 are then driven at the same speed to drive the vehicle along the road or through gateways. When driving the vehicle in the field mode, the castor wheels 22, 27 lie immediately in line with the adjacent wheels 17, 21 and when travelling in the road mode, the wheels 22, 27 automatically turn through 90 degrees due to the castor action. They then run parallel with the wheels 17, 21.

When the vehicle is being driven in the road mode the operation of a steering wheel 64 in the cab 60 causes the leading wheel (normally 17) to steer.

In Fig.12 the cab 60 includes a control section 62 including a two way switch.63 in an electrical supply circuit by means of which a field mode control unit FM or a road mode control unit RM can be brought into operation. Fluid is fed to the control section along lines 62a, 62b from the pump.

In field mode, rotation of a steering wheel 64 will be sensed by a position sensor 65 such as a rotary potentiometer which provides signals by means of which fluid is fed to the motors 17a, 21a independently through lines 17b, 21b to vary the relative speeds of the wheels 17, 21 which are positioned as shown in full lines. If the speeds of both wheels are to be changed by the same amount simultaneously so as generally to increase or decrease speed, the steering wheel 64 can be moved forwards or backwards about an axis X. A movement sensor 66 such as a potentiometer senses movement of a steering column 67 in that case and produces a signal which is transmitted to a speed control unit 166 used to control the speed of the wheels simultaneously.

By switching to field mode it then becomes impossible to steer the wheels by changing their relative speeds. On operation of the switch 63 to select road mode, the wheels, 17, 21 are turned by associated steering rams 68, 69 into the positions shown in broken lines. Fluid is fed to the rams along lines 68a, 69b respectively. When driving in the road mode, the control section 62 enables fluid to be fed to the motors 17, 21 so that the speeds of motors 17, 21 are equal. However the speeds can be varied simultaneously by speed control unit 166 by moving the steering wheel about axis X. Steering in the road mode is effected by rotation of the steering wheel as described below with reference to Fig.13.

However, except when travelling round relatively shallow corners, it is often desirable for the rear wheel 21 not to steer during steering movement of the front wheel 17. Therefore, the steering system includes a control section 70 having hydraulic circuitry which permits the rear wheel 21 to be steered only after the front wheel 17 has been steered beyond a certain angle G from the straight ahead position. Typically, such an angle may be around 10 degrees but may be set differently if required. In that way, when negotiating relatively shallow curves, slight steering movement of the front wheel 17, e.g., through angle G1 , will not cause the rear wheel 21 to steer thereby avoiding unwanted outward swinging movement of the rear end of the vehicle. However when the wheel 17 reaches angle G, which is sensed by the potentiometer 65, the latter provides a signal to the control section 70 which permits fluid to flow to ram 69 causing the wheel 21 to turn in an opposite direction to the same angle as the wheel 17 as shown in the right hand diagram of Fig.13. Further steering movement of the wheel 17 beyond angle G, e.g, to G2 will cause wheel 21 to steer to that angle. The steering of the wheels 17, 21 in road mode is effected by the steering rams 68, 69.

If desired, a steering control section 71 can be selected whereby hydraulic circuitry of the control section enables the wheels 17, 21 to be steered independently. Steering wheel 64 is then used to

_SUB_STITU_TESHEET steer the wheel 17 and a small control knob 71a is provided on the control section 71 which is rotated manually to cause wheel 21 to steer. This is useful for manoeuvring in restricted spaces.

If the user always requires the wheel 21 to be locked in a straight ahead position in road mode so that only wheel 17 can be steered a steering control section 72 can be selected. Control section 71 includes hydraulic circuitry which permits fluid to flow to ram 68 but which prevents flow of fluid to ram 69.

In Figs.12 and 13 only fluid feed lines 68a, 69a to the rams 68, 69 for one direction of movement are illustrated. Fluid return lines are omitted for clarity. Similarly fluid feed lines 17b, 21b for the motors 17, 21 are shown and return lines omitted.

As mentioned above, the main section 11 can be used to carry various tools and for that purpose the elongate section 11 can carry a plurality of linkages L of the kind shown in Fig.14 and 15.

In Fig.14, the elongate section 1 is shown in cross- section and two opposite linkages L are shown. Preferably, a plurality of such sets L1 , L2 and L3 (Fig.17) is provided at spaced apart positions along

SUBSTi i^'ϋ^'fc Hise ι the elongate section 11. One linkage is shown on the left-hand side of the elongate section 11 in Fig.14 and comprises a fluid operable actuator 80 having an output rod 80a pivotally connected at 80b to one end of a first arm 82. The actuator 80 is pivotally mounted on a bracket 89. The arm 82 is pivotally connected at 82a intermediate its ends to a mounting bracket 83 carried on the elongate section 11. The arm 82 has spaced apart left-hand ends 82a pivotally connected to a second arm 84 at a position intermediate its ends. The arm 84 defines spaced apart members 84a provided with mounting claws 85 which supports e.g., a spray boom 86 (Fig.14). The opposite end of the second arm 84 is pivotally connected to one end of a third arm or link 87 of fixed length, the opposite end of which is connected above the pivotal connection 82a to a bracket 88 fixed to the bracket 89. The second linkage set on the opposite side of the boom is a mirror image of the first linkage and is not described in detail. The various components carry corresponding reference numerals. The support bracket 89 is bolted to a bridge piece 90 which extends across the upper half hexagon section 28 to support the linkages. The support brackets 89 are also connected to sling pieces 92 whic extend beneath the lower half hexagon section 29 of the elongate section 11. The linkages are, thereby, firmly connected to the elongate section 11. The cylinder of

S_UBS_TITUTESHEET each actuator 80 is pivotally connected to the associated bracket 89. The solid line position of the arms in Fig.14 illustrate the position of the arms when carrying the spray boom 86 in a working position. To move the spray boom 86 from a working position to a stowed position as shown in broken lines at B in Fig.14, the actuator 80 is extended to swing the first arm 82 about its pivotal connection with bracket 83, the position B representing the position of the claw 85 when the actuator is fully extended as indicated at position E.

If desired, spray booms can be carried simultaneously by both linkages L. If desired, the elongate section 11 can carry resilient pads such as rubber blocks against which the claws 85 will rest when in the stowed position.

Referring now to Figs^16 and 17, a spray boom 100 shown diagrammatically in Fig.16 comprises a fixed main boom 81 which, in use, attaches to the claws 85 of spaced apart linkages L1 , L2 and L3 as shown diagrammatical ly in Fig.17. The boom 81 may be of box section, but, in Fig.16 is shown as an angle section for simplicity and clarity. For lightening purposes, the boom, which carries spray nozzles (not shown), may be formed with lightening holes. Only one end of the main boom is shown in Fig.16. At the end of the main boom 81 shown, a first boom extension 91 is pivotally connected. The first boom extension comprises a channel member 93 having upper and lower hinge arms 94 by means of which it is pivotally connected to the main boom 81. The first boom extension 91 is, in use, provided with spray nozzles (not shown) in the same way as the main boom 81 but, for clarity the nozzles are not shown._. The extension 91 can be pivoted into an extended position 91a.

A second boom extension 95 of length no more than half the length of the main boom 81 may be stowed to the rear of the main boom 81 on attachment means (not shown) by which the main boom and second extension are held together. The second boom extension fits within the channel 93 and can be bolted to the first boom 91 extension whereby the second boom extension 95 may be hinged into an operative position as shown at 95a. The part extending from channel 93 is provided with spray nozzles (not shown).

The second boom extension is pivotally connected to a third boom extension 96 which may be folded onto the top of the second boom extension 95 about a horizontal hinge 97 extending transverse to the second and third boom extensions. With the second boom extension in position 95a, the third boom extension 96 can be hinged outwardly to position 96a. The outward folded positions of the boom extensions can also be seen in Fig.17 where the first and second boom extensions 93, 95 extend the boom to the full width of the vehicle, and the third boom extensions 96 extend the boom well beyond the ends of the vehicle. Once the boom increases in length through the various extensions, it becomes easier for the driver to strike an upstanding object such as a post with an end of the extended boom when driving the vehicle. In order to reduce the likelihood of damage occurring when either outer end of the boom strikes such an object, the third boom extension 96 may comprise first and second parts 98, 99. The part 98 includes two projections 103 which locate in sockets 101 in the second part 99. The parts 98, 99 are urged together by springs 102 on opposite sides of the extension. If the outer part 99 of the extension 96 strikes an object when the vehicle is being driven, the extension can effectively "break" by tipping about the front or rear projection, such tipping expanding the spring 102 which brings the projections and sockets into re-engagement once the obstruction has been cleared.

All of the operational functions of the vehicle can be controlled from the cab. However, for convenience, the

SUBSTITUTESHEET locking members 59 used when raising the intermediate sections 14, 15 upwardly along the slideways 49 are operated manually.

If desired, the vehicle may be used to tow ground tilling tools such as a harrow and/or plough and has the great advantage that the length of the boom permits the vehicle to be driven across a field a number of times creating far less damage to crops as there will be fewer wheel ruts than when using a conventional tractor.

The hydraulic motors 17a, 21a may be positioned within steerable hollow mounting sections 12a, 13a on the chassis sections 12, 13 and hydraulic conduits for the motors also lie within the sections 12a, 13a for protection.

Hydraulic fluid supply for the rams 55 for raising and lowering the elongate section 11 is supplied by the pump 70 housed in the intermediate section 14 and operation of the rams is effected by means of a control unit (not shown) in the cab 60.

The intermediate sections 14, 15 will normally be covered by a suitable casing which is omitted in Figs.5 to 11.

SUBSTITUTESHEET

Claims

1. The vehicle comprises a structure including an elongate section 11, at least- one driving wheel carried by a further section of the structure adjacent each end of the elongate section, drive means for driving the vehicle in a direction transverse to or longitudinally of the structure, and a height adjustment device arranged to lift or lower the elongate section of the structure relative to the further sections.

2. A vehicle according to Claim 1 in which each end of the elongate section is connected to the further section by guide means which permits said height ad ustment.

3. A vehicle according to Claim 2 in which the guide means comprises an upwardly extending rail.

4. A vehicle according to Claim 3 in which the rail forms a guide for a member movable therealong, the rail being connected to one of the associated further and elongate sections and the member being connected to the other of the associated further and elongate sections.

5. A vehicle according to Claim 3 or 4 in which each guide means comprises two spaced apart rails.

6. A vehicle according to Claim 3, 4 or 5 in which the or each rail is of channel shape.

7. A vehicle according to Claim 6 and where said member is provided which is movable along the rail, in which the member is positioned in the channel.

8. A vehicle according to Claim 7 in which two spaced apar-t channel shaped rails are provided with respective members positioned thereon.

9. A vehicle according to any preceding Claim in which the elongate section is connected to at least one of the further sections through an intermediate section.

10. A vehicle according to Claim 9 in which the elongate section is connected to both further sections through respective intermediate sections.

11. A vehicle according to Claim 9 or 10 when appendant to any of Claims 2 to 8 in which the or each intermediate section is connected to its associate further section by said guide means.

12. A vehicle according to any preceding Claim in which the height adjustment device is in the form of a fluid operable ram or other actuator.

13. A vehicle according to Claim 12, in which the actuator is attached between first and second points on the structure and is arranged to raise the elongate section from a lower position to a higher intermediate position at which it can be retained, the actuator then being arranged to attach between said first point and a third point of the structure to enable the. elongate section to be raised to its highest position.

14. A vehicle according to Claims 12 or 13 wherein the second and third points are provided on a common member.

15. A vehicle according to any preceding Claim in which at least one end of the elongate section includes fillets which enable the elongate section to be connected to the adjacent further section.

16. A vehicle comprising a structure including an elongate section, at least one wheel carried by a further section of the structure adjacent each end thereof, drive means for driving the vehicle in a direction transverse to or longitudinally of the structure, at least one end of the main section including fillets which enable the elongate main section to be connected to the adjacent further section.

17. A vehicle according to Claim 15 or 16 in which the fillets extend along peripheral portions of the elongate section so as to provide reinforcement.

18. A vehicle according to any preceding Claim in which the elongate section forms a hollow frame which surrounds conduit associated with fluid circuitry of the vehicle.

19. A vehicle according to any preceding Claim with at least one of the further sections includes a mounting on which a cab is supported.

20. A vehicle comprising a structure including an elongate section, at least one wheel carried by a further section of the structure adjacent each end thereof, and drive means for driving the vehicle in a direction transverse to or longitudinally of the structure at least one of the further sections including a mounting on which a cab is supported.

21. A vehicle according to Claim 19 or 20, in which the further section having the cab includes a surrounding member mounted on the further section and which extends around at least part of the cab to form a fender.

22. A vehicle according to Claim 21 in which the cab surrounding member extends beneath the cab.

23. A vehicle according to Claim 22 in which the cab surrounding member forms said moulding and has thereon resilient mounting means for the cab.

24. A vehicle according to Claims 21 to 23 in which two surrounding members are provided extending adjacent front and rear sections of the cab.

25. A vehicle according to Claims 21 to 24, in which the other further section includes one or more similar surrounding members to protect a container thereon.

26. A vehicle according to any preceding Claim in which each further section includes a pivotal mounting for a further wheel .

27. A vehicle according to Claim 26 in which each further section is provided with a mounting for a further wheel.

28. A vehicle according to Claim 27, in which the further wheel is aligned with the steerable wheel when the vehicle is being driven in the direction transverse to the structure.

29. A vehicle as claimed in Claim 28, in which the wheel is mounted on an arm which may be raised and lowered relative to its further section.

30. A vehicle according to any preceding Claim in which the two further sections are substantially identical.

31. A vehicle according to any preceding Claim in which a motor or engine housing is provided between at least one further section and the adjacent end of the elongate section.

32. A vehicle according to Claim 31, in which an engine drives the vehicle.

33. A vehicle according to Claim 32 and where a cab is provided on one of the further sections, in which a housing for the engine is arranged adjacent the further section on which the cab is mounted.

34. A vehicle according to Claim 31, 32 or 33 and where said intermediate section is provided, in which the housing is formed by said intermediate section.

35. A vehicle according to any preceding Claim including steering means for steering the wheels when the vehicle is travelling in the direction longitudinally of the structure, control means being provided to enable the steering means to steer one of the wheels after the other has been steered by a predetermined amount.

36. A vehicle comprising an elongate structure, at least one wheel carried at each end of the structure, drive means for driving the vehicle in a direction transverse to or longitudinally of the structure, steering means for steering the wheels when the vehicle is travelling in the direction longitudinally of the structure, and control means which enables the steering means to steer one of the wheels after the other has been steered by a predetermined amount.

37. A vehicle according to Claims 35 or 36 in which the said control means enables the other wheel to be steered up to around 10 degrees without steering movement being applied to the said one wheel.

SUBSTITUTE SHEET

38. A vehicle according to Claims 35, 36 or 37 in which said control means also enables the wheels to be steered independently of each other, one wheel only to be steered or both wheels steered simultaneously.

39. A vehicle according to Claim 38 in which the selection of the steering mode of the vehicle can be effected from a cab on the vehicle.

40. A vehicle according to any preceding Claim in which there is provided a linkage for connecting a tool to the vehicle, the linkage comprising a first arm pivotally connected to a support means of the vehicle, a second arm for carrying the tool and being pivotally connected to the first arm intermediate its ends, a third arm pivotally connected to the second arm at a point spaced from the pivotal connection to the first arm and which is pivotally connected at its other end to the support means or a member connected thereto, and actuator means for pivoting at least one said arm whereby the tool can be moved from an operative position adjacent the ground to a stowed position clear of the ground.

41. A vehicle including a linkage for connecting an agricultural tool to an agricultural vehicle comprising a first arm pivotally connected to a support means of the vehicle, a second arm for carrying the tool and being pivotally connected to the first arm intermediate its ends, a third arm pivotally connected to the second arm at a point spaced from the pivotal connection to the first arm and which is pivotally connected at its other end to the support means or a member connected thereto, and actuator means for pivoting at least one said arm whereby the tool can be moved from an operative position adjacent the ground to a stowed position clear of the ground.

42. A vehicle according to Claim 40 or 41, in which the tool is carried at an end of the second arm spaced form the connection between the second arm and third arm.

43. A vehicle according to Claims 40, 41 or 42 in which the third arm is pivotally connected to the support means above the pivotal connection between the first arm and support means.

44. A vehicle according to any of Claims 40 to 43 in which one end of the actuator means is pivotally connected to the support means.

45. A vehicle according to Claim 44 in which the other end of said actuator is pivotally connected to the first arm.

46. A vehicle according to Claim 45, in which the actuator is pivotally connected to the first arm at a position to one side or to the other side of the pivotal connection between the first arm and the support means.

47. A linkage according to any of Claims 40 to 46 in which the third arm crosses the first arm when viewed in a direction axially of the pivotal connections.

48. A vehicle comprising a structure including an elongate section, having at least one wheel carried by a further section of the structure at each end thereof, and drive means for driving the vehicle in a direction transverse to or longitudinally of the structure, the elongate section providing or defining support means for first and second linkages on opposite sides of the elongate section, each linkage including pivotally interconnected arms by means of which apparatus can be connected to the vehicle, each linkage including actuator means for causing the arms to move so that a tool carried by one or each of the linkages can be moved from an operative position to a stowed position.

SUBSTITUTE SHEET

49. A vehicle according to any of Claims 40 to 48 in which the or each actuator means is operable independent1y.

50. A vehicle according to any of Claims 40 to 49 in which each linkage is arranged to move the tool from a position which is lower than at least part of the support means in its operative position to a stowed position well clear of the ground.

51. A vehicle according to any of. Claims 40 to 50 in which attachment means on each linkage for a tool or the like is positioned generally adjacent the support means when in the stowed position or engages the support means.

52. A vehicle according to any of Claims 40 to 51, in which two or more such linkages are arranged on the support means at spaced positions therealong.

53. A vehicle according to any of Claims 40 to 52, in which two pairs of linkages are provided on opposite sides of the elongate section and a tool is carried by each pair.

54. A vehicle according to any preceding Claim, in

SUBSTITUTE SHEET which certain of the wheels are steerable and also drivable to effect movement of the vehicle.

55. A vehicle according to Claim 54, in which a conduit for drive fluid is contained in hollow wheel mountings to provide protection for the conduit.

56. A vehicle according to Claim 55 in which the control means is provided whereby the drivable wheels cannot be driven at relative speeds when the vehicle is travelling longitudinally of the elongate structure.

" 57. A vehicle according to any preceding Claim in which the elongate structure is arranged to support a tool or implement substantially in the form of a boom.

58. A vehicle according to Claim 57, in which the boom is extensible up to or beyond the ends of the vehicle.

59. A vehicle according to Claim 58, in which the boom is extensible by providing an extension part pivotally connected to a main boom part and which can be moved from a stowed position alongside the main boom to a position extending longitudinally therefrom.

60. A vehicle according to Claim 59, in which the extension includes a second extension part which is movable from a stowed position alongside or overlying the first extension part and which is movable into an extended position extending longitudinally of the first extension part.

61. A vehicle according to Claim 60, in which a third extension part can be connected to the second extension part for movement into its extended position.

62. A vehicle according to any of Claims 59 to 61 in which the first extension part pivots about a substantially vertical axis into its extended position.

63. A vehicle according to Claim 62 and where the third extension part is provided, in which the third extension part is pivotally connected to the second extension part about an axis which extends generally horizontally transverse to the elongate structure.

64. A vehicle according to any of Claims 60 to 63, in which the second or, where provided the third, boom extension part comprises two parts which are held in end to end abutment by means of a resilient interconnection.

65. A vehicle according to Claim 64, in which the resilient interconnection preferably allows said parts to be articulated relative to each other.

66. A vehicle according to Claims 64 or 65, in which the abutment between the two parts comprises horizontally spaced apart abutments on one of the parts.

67. A vehicle according to Claims 61 to 66 and where each end of the boom is provided with an extension arrangement, in which the first, second and third extensions, when in stowed positions, are arranged alongside the main boom.

68. A vehicle according to Claim 67, in which the extensions in their stowed position occupy no more than half the length of the main boom section.

69. A linkage for connecting an agricultural tool to an agricultural vehicle comprising a first arm pivotally connected to a support means of the vehicle, a second arm for carrying the tool and being pivotally connected to the first arm intermediate its ends, a third arm pivotally connected to the second arm at a point spaced from the pivotal connection to the first

SUBSTITUTESHEET arm and which is pivotally connected at its other end to the support means or a member connected thereto, and actuator means for pivoting at least one said arm whereby the tool can be moved from an operative position adjacent the ground to a stowed position clear of the ground.

70. A linkage according to Claim 69 in which the tool is carried at an end of the second arm spaced from the connection between the second arm and third arm.

71. A linkage according to Claims 69 or 70 in which the third arm is pivotally connected to the support means above the pivotal connection between the first arm and the support means.

72. A linkage according to claim 69, 70 or 71 in which one end of the actuator means is pivotally connected to the support means.

73. A linkage according to Claim 72 in which the other end of said actuator is pivotally connected to the first arm.

74. A linkage according to Claim 73 in which the actuator is pivotally connected to the first arm at a position to one side or to the other side of the

SUBSTITUTE SHEET pivotal connection between the first arm and the support means.

75. A linkage according to any of Claims 69 to 74 in which the third arm crosses the first arm when viewed in a direction axially of the pivotal connections.

SUBSTITUTE SHEET