GB2078640A

GB2078640A - Tracked agricultural vehicle

Info

Publication number: GB2078640A
Application number: GB8016900A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1980-05-22
Filing date: 1980-05-22
Publication date: 1982-01-13
Also published as: GB2078640B

Abstract

A vehicle for use on the land has endless tracks (37) one mounted on each side of the vehicle. Drive to the each track is achieved through a driven sprocket wheel (38) and chain tension is achieved by adjustment of the axle position of the front wheels (26). The axle of the rear wheels (28) is sprung as also is a bogey assembly (32, 34). An idler (36) supports the track (37) on its return from the rear wheels to the driven sprocket wheel. Each track is made up of two endless belts (40, 42) which are bridged by metal cleats (44) and hoops (48, 50) are located beneath the belts to provide a degree of lateral location for the belt relative to the wheels, the external peripheries of which are recessed to accommodate the hoops (48, 50). The sprocket wheels (38) are driven by respective hydraulic motors supplied by pumps driven by an engine (22) located centrally of the vehicle. A driving cab (12) is located at the forward end of the vehicle, and a spray boom (14) is mounted at the rear with provision for height adjustment. <IMAGE>

Description

SPECIFICATION Improvements in agricultural vehicles Field of the Invention This invention relates generally to agricultural vehicles and in particular to a tracked agricultural vehicle carrying apparatus for the treatment of land and/or crops, such as spraying apparatus.

Background to the Invention The treatment of agricultural land and/or crops, for example with spraying apparatus, is necessary at all times of the year, including periods, often in winter and early spring, when the ground is extremely soft and wet. Apart from the difficulty of driving and manoeuvring a conventional tractor on such land, soft and muddy earth is liable to damage due to compaction by the tractor wheels.

It is an object of this invention to provide an alternative agricultural vehicle which minimises or avoids problems created by the use of a conventional tractor on soft and wet land.

The Invention According to the invention, there is provided a tracked agricultural vehicle carrying apparatus for the treatment of land and/or crops, said vehicle having an endless track on each side, each said track having fittings engaging cooperating means on the peripheries of a series of wheels around which the track is located, said series of wheels comprising front and rear main wheels between which a ground engaging section of the track extends past sprung bogies, and an idler wheel and a driven sprocket wheel on the return section of the track, the sprocket wheels driving the respective tracks being driven by an hydraulic motor powered from a fuelled engine.

The tracked vehicle according to the invention need be of no greater overall weight than a conventional tractor and, having its weight distributed over tracks of substantial area, is much less liable to damage the land. In addition, since it is less liable to sink into soft and wet earth, it is easier to handle than a conventional tractor under adverse condition. Preferably, each track will have a width of the order of one quarter of the overall width of the vehicle, and the ground engaging section will be made as long as practicable, of the order of three quarters of the length of the vehicle.

The vehicle is especially well adapted to carry a spray boom for crop and land spraying. Such a boom will preferably be mounted at the rear, in conjunction with a device for adjusting its height, whilst a driving cab will be provided at the front of the vehicle. The centre portion of the vehicle is then free to support a diesel engine and one or more hydraulic motors. This arrangement ensures a balanced weight distribution.

Preferably, the front and rear main wheels are carried by front and rear axles, at least one of which is sprung and at least one of which is adjustable to adjust track tensions. The sprung bogies are generally sufficient in themselves to accommodate unevennesses in the ground, so that one main wheels axle, preferably the rear main wheels axle, may be unsprung. This axle may then be the adjustable axle in respect of track tensions. The idler wheel is preferably mounted above the sprung bogies to engage the return section of the track, and may be sprung, but is preferably unsprung.

There are preferably two hydraulic motors, one for each driven sprocket wheel, powered from a single engine. Two individually controllable hydraulic motors, one for each track, enable the vehicle to be flexibly manoeuvred.

An important aspect of the invention resides in the construction of the tracks.

Thus, in a preferred arrangement, each track comprises a pair of spaced parallel endless belts, e.g. of rubber, bridged by longitudinally spaced metal cleats. Behind each belt, i.e. on the inner face of the track, the track is provided along its length with a series of spaced hoops, formed by bending strip metal. Nuts and bolts or like securing means can serve both to connect the cleats between the spaced parallel belts of each track and to secure the hoops, which extend transversely of the length of the track, to the belts.

A pair of hoops, one for each belt, may be provided at each cleat, or a lesser number of hoops may be sufficient. In use, the hoops engage in correspondingly spaced grooves provided across the peripheral surfaces of the main wheels, the bogies and the idler wheel, thereby to retain the track in position. The driven sprocket wheel on each side of the vehicle, which drives the respective track, has teeth which engage between the longitudinally spaced cleats. The sprocket wheel is narrower than the other wheels so that its full width teeth engage between the cleats centrally in the transverse direction, between the belts and the hoops secured thereto.

In the Accompanying Drawings:- Figure 1 is a side elevational view of a tracked agricultural vehicle; Figure 2 is a plan view thereof; Figure 3 is a front view thereof; Figure 4 is a rear view thereof; Figure 5 is a diagrammatic perspective view of a portion of one of the vehicle tracks; Figure 6 is a transverse sectional view of a track; and Figure 7 is a perspective view of a metal hoop forming part of the track.

Description of Embodiment In Figures 1 to 4 is shown a tracked vehicle 10 having a front driving cab 1 2. At the rear of the vehicle is mounted a spray boom 14 carrying a spray bar 1 6. A fluid reservoir is indicated at 18, whilst the reference 20 generally denotes a winch device which enables the height of the spray boom 14 to be adjusted. The centre portion of the vehicle 10 carries a unit 22 incorporating a diesel engine and a pair of hydraulic motors, one for each of a pair of opposed endless tracks 24 provided on opposite sides of the vehicle.

Each track 24 is retained to extend around a series of wheels which include front and rear main wheels 26 and 28 between which extends a ground engaging section 30 of the track. Two sprung bogie pairs 32 and 34 engage the central region of the track ground engaging section 30.

Above the sprung bogies 32, 34 is mounted an idler wheel 36 engaging the return section 37 of the track. The idler wheel is shown unsprung, but could alternatively be sprung. At the front of the vehicle, the track 24 engages a driven sprocket wheel 38. The sprocket wheel 38 is driven by one of the above-mentioned hydraulic motors.

The main wheels are preferably carried by front and rear axles (not shown) extending across the full width of the vehicle. The front wheels axle is preferably sprung, whilst the rear wheels axle is preferably unsprung, but is adjustable in position to adjust the tracks tension. It will be appreciated that, in the above described arrangement, the separate hydraulic motors, which are individually controllable, enable the vehicle to be handled and manoeuvred with high flexibility.

The construction of the endless tracks is illustrated in Figures 5 to 7. Basically, as shown in Figure 5, each track 24 comprises a pair of endless rubber belts 40, 42 joined by longitudinally spaced metal cleats 44 which have a slightly arched outer surface 46 for ground engagement. Furthermore, as shown more clearly in Figure 6, behind the belts 40, 42, i.e. on the inside surface of the track, are secured respective series of longitudinal strip metal hoops 48, 50.

One such hoop 48 is shown more clearly in Figure 7. The belts 40, 42, cleats 44 and hoops 48, 50 (one series behind each belt) are secured together by nuts and bolts 52. It will be noted that the hoops 48, 50 extend transversely of the track.

Hoops 48, 50 may be secured in position at each cleat 44, or at alternate cleats or at a still lesser number of cleats. the hoops 48, 50 engage correspondingly spaced grooves extending across the peripheral faces of the main wheels, bogie wheels and idler wheel (as will be clear without further illustration), thereby to retain the track in position. In a typical case, the belt may have a thickness of about 1.25 mm and the hoop height may be about 6.25 mm.

As will also be clear without further illustration, the driven sprocket wheel 38 has teeth which engage between the cleats 44 in order to drive the track. The sprocket wheel 38 is appreciably narrower than the track, so that its full width teeth pass between the belts 40, 42. The engagement between the sprocket wheel teeth and the cleats is such as to achieve a continuous steady drive.

It will be appreciated that the tracked agricultural vehicle of this invention has substantial advantages over a conventional tractor for use on soft, wet and muddy land (although not being restricted to such use), and can be equipped with various items of agricultural apparatus and machines additional to or in place of the spraying equipment which has been illustrated.

Claims

1. A tracked agricultural vehicle carrying apparatus for the treatment of land and/or crops comprising a) an endless track on each side of the vehicle, b) each said track having fittings engaging cooperating means on the peripheries of a series of wheels around which the track is located, c) said series of wheels comprising front and rear main wheels between which a groundengaging section of the track extends past sprung bogies, d) an idler wheel and a driven sprocket wheel on the return section of the track, and e) wherein the sprocket wheels driving the respective tracks are driven by an hydraulic motor powered from a fuelied engine.

2. A tracked vehicle as claimed in claim 1 in which each track has a width of the order of one quarter of the overall width of the vehicle.

3. A tracked vehicle as claimed in claim 1 or 2 in which the ground-engaging section is up to three-quarters the length of the vehicle.

4. A tracked vehicle as claimed in any of claims 1 to 3 in which the apparatus for the treatment of land and/or crops comprises the spray boom for crop and land spraying.

5. A tracked vehicle as claimed in claim 4 in which the boom is mounted at the rear of the vehicle in conjunction with a device for adjusting its height.

6. A tracked vehicle as claimed in any of claims 1 to 5 in which a driving cab is located at the front of the vehicle.

7. A tracked vehicle as claimed in any of claims 1 to 6 wherein a fuelled engine typically a diesel engine is mounted centrally of the vehicle together with one or more hydraulic motors.

8. A tracked vehicle as claimed in any one of claims 1 to 7 in which the front and rear main wheels are carried by front and rear axles respectively at least one of which is sprung and at least one of which is adjustable to adjust track tensions.

9. A tracked vehicle as claimed in claim 8 in which the rear main wheels axle is unsprung and is itself adjustable in respect of track tension whilst the front main wheel axle is fully sprung.

10. A tracked vehicle as claimed in claim 9 in which the idler wheel is mounted above a sprung bogey to engage the return section of the track.

11. A tracked vehicle as claimed in any of the preceding claims in which there are two hydraulic motors one for each driven sprocket wheel powered from a single engine to facilitate the control and manoeuvrability of the vehicle.

12. In a tracked vehicle as claimed in any of the preceding claims a track construction comprising i) a pair of spaced parallel endless belts, ii) a plurality of longitudinally spaced metal cleats bridging the belts, and iii) locating abutments on the rear of the belts for engaging in peripheral grooves in the surface of at least one of the wheels around which the belts pass to laterally locate the belts.

13. A track for a tracked vehicle as claimed in claim 12 in which the locating abutments or protrusions comprise a plurality of spaced hoops formed by bending strip metal secured to the rear of the track by means of nuts and bolts or like securing means.

14. A track for a tracked vehicle as claimed in either of claims 12 or 13 in which the nuts, bolts or like securing means serve both to connect the cleats between the spaced parallel belts of each track and to secure the hoops which extend transversely of the track, to the belts.

1 5. A track for a tracked vehicle as claimed in claim 14 in which a pair of hoops, one for each belt, are provided at each cleat.

1 6. A track for a tracked vehicle as claimed in claim 1 5 wherein the driven sprocket wheel on each side of the vehicle which drives the respective track has teeth which engage between the longitudinally spaced cleats and the sprocket wheel is narrower than the other wheels so that its full width teeth engage between the cleats centrally in the transverse direction between the belts and the hoops secured thereto.

17. A tracked vehicle as claimed in claim 1 constructed and arranged and adapted to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.

1 8. A tracked vehicle when fitted with a track constructed and arranged substantially as herein described with reference to and as illustrated in the accompanying drawings.