GB2034161A - An agricultural spraying vehicle - Google Patents

Abstract

A spraying vehicle has a motor 4 which drives the road wheels 3. A liquid pump 9 is also driven by the output shaft of the motor 4, so that the rate of operation of the pump 9 is directly proportional to the speed of the vehicle. The pump 9 pumps liquid from reservoir 8 to spray booms 10 via a distributor chamber 20. The vehicle has front and rear suspension designed to keep the spray booms in the same relative orientation to the land during spraying. <IMAGE>

Description

SPECIFICATION An agricultural spraying vehicle This invention relates to an agricultural spraying vehicle, and in particular to a selfpropelled crop spraying or ground spraying vehicle.

According to the present invention, there is provided a self-propelled agricultural spraying vehicle having a motor for driving groundengaging wheels of the vehicle to propel the vehicle, a reservoir for containing liquid to be sprayed, and a pump for pumping liquid from the reservoir to spraying devices mounted on the vehicle, wherein the pump is a constant delivery pump and is driven from the drive shaft of the motor, so that the rate of delivery of the pump varies in accordance with the ground speed of the vehicle.

A clutch, preferably a dog clutch may be provided between the drive shaft and the pump, so that the pump can be disengage when the vehicle is driven along the road.

The pump preferably pumps spray liquid to the spraying device via a distribution chamber which controls the volume of liquid sprayed by the device. The distribution chamber can preferably be adjusted to vary the volume of liquid sprayed.

The driving of the pump from the drive shaft of the vehicle has the advantage that the vehicle does not have to be driven, during spraying, at a constant speed in order to ensure constant application of the sprayed liquid to the land.

Because a greater volume of liquid is sprayed when the vehicle speed rises, the vehicle can be driven, while spraying, at a higher speed than was hitherto possible. Also, when the vehicle stops, e.g. at the edge of a field, no liquid is sprayed.

With conventional sprayers, it often happens that the edges of the fields and other places where the spraying vehicle has to slow down and turn receive an overdose of sprayed liquid.

The vehicle preferably on both front and rear wheels. This ensures that the spraying device, which will normally be a pair of two-line spray booms, remains in the same orientation relative to the land, even though the land over which the vehicle is being driven is rough. This improves the evenness of application of the liquid being sprayed.

The front suspension may comprise a single shock absorber and spring connected between the mid point of the front axle and the chassis, with a pair of rigid links connected on either side respectively to the chassis and to the axle by means of ball joints.

The rear suspension may comprise shock absorbers and springs at each side of the rear axle connected between the axle and the chassis, a Vshaped strut connected to two points on the axle and one point on the chassis by means of ball joints, and a diagonal bracing strut behind the axle connected between the axle and the chassis to locate the axle relative to the chassis.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic view of a vehicle according to the invention; Figure 2 is a plan view of the front suspension; Figure 3 is a plan view of the rear suspension; and Figure 4 is a schematic diagram of the liquid dispensing system.

The vehicle shown in Figure 1 has a chassis 1, front wheels 2 and rear wheels 3. The rear wheels 3 are driven by a motor 4 via a drive shaft 5. The motor 4 may be a conventional internal combustion engine, which drives the drive shaft 5 through a gear box. The front wheels 2 are steered in a conventional manner by a steering wheel 6, and the vehicle is driven from a driving position 7 at the front.

The vehicle also has a tank 8 for containing the liquid to be sprayed, a pump 9 and spray booms 10 which are shown in the folded, out of operation position. The pump 9 is a constant delivery pump, for example a piston pump, and is driven directly from the drive shaft 5. In Figure 1, a belt connection between the pump 9 and the shaft 5 is shown. This may be a notched belt, but any other suitable non-slip drive connection between the shaft 5 and the pump 9 may be used. A dog clutch (not shown) is positioned between the pump 9 and its drive shaft, so that the pump 9 can be disengaged when the vehicle is to be driven without spraying taking place.

The front suspension is shown in Figure 2, and comprises a shock absorber and spring 11 centrally connected between a chassis portion 1 2 and the front axle 1 3. On either side of the chassis are rigid links 14 connected to the chassis and to the axle 1 3 by ball joints 1 5. The axle can therefore pivot about the centre, while being maintained transverse to the direction of travel bv the struts 14.

The rear suspension shown in Figure 3 has at least two shock absorbers or springs 11 connected between the rear axle 1 6 and the chassis 1. Additionally, a V-shaped strut 1 7 is connected to a chassis bar 1 8 by a ball joint 15, and on two points on the axle 1 6. A diagonal strut 19 is connected, by means of ball joints 15, between the axle 1 6 and the chassis 1 to locate the axle transversely of the vehicle.

The liquid to be sprayed is fed to the spray booms 10 by the system shown in Figure 4. The liquid stored in tank 8 is pumped by pump 9 to a distributor chamber 20. This chamber has two outlets 21, 22. to the spray booms 10 and a further outlet 23 through a plate 24 back to the top of the tank. There may be more than two outlets (for example, four) to the spray booms when large volumes of liquid are to be sprayed.

The size of the opening 23 in the plate 24 determines the relative quantities of water flowing through the outlets 21 and 22 and flowing through the duct 25 back to the tank. The plate 24 can be exchanged for another plate with a different sized opening 23 when it is desired to vary the relative quantities. It will be seen that the plate 24 is held in position by a screw cap 26 which can be easily removed to replace the plate.

A pressure relief valve 27 venting into the tank 8 is also provided to guard against excessive pressure being produced in the chamber 20.

Conventional ON/OFF valves, operated from the driving position 7, will be provided in the outlets to the spray booms.

It is a major advantage of this purpose designed vehicle that it will be very light in weight compared to known self-propelled spraying vehicles. The unladen weight may be about half a ton, so that the laden weight should not exceed one ton, and this light weight together with the suspension used will enable the vehicle to operate under adverse ground conditions. It is anticipated that the vehicle described will be able to carry out spraying at speeds of up to 20 miles per hour. The pump 9 may be of any suitable type producing a constant delivery, and in this application a 22 gpm output pump will be suitable.

Claims (8)

1. A self-propelled agricultural spraying vehicle having a motor for driving ground-engaging wheels of the vehicle to propel the vehicle, a reservoir for containing liquid to be sprayed and a pump for pumping liquid from the reservoir to spraying devices mounted on the vehicle, wherein the pump is a constant delivery pump and is driven from the drive shaft of the motor, so that the rate of delivery of the pump varies in accordance with the ground speed of the vehicle.

2. A vehicle as claimed in claim 1, wherein a dog clutch is provided between the drive shaft and the pump, so that the pump can be disengaged when the vehicle is driven along a road.

3. A vehicle as claimed in claim 1 or claim 2, wherein the pump pumps spray liquid to the spraying devices via a distribution chamber which controls the volume of liquid sprayed by the device.

4. A vehicle as claimed in claim 3, wherein the distribution chamber can be adjusted to vary the volume of liquid sprayed.

5. A vehicle as claimed in any preceding claim, with suspension on both front and rear wheels.

6. A vehicle as claimed in claim 5, wherein the front suspension comprises a single shock absorber and spring connected between the midpoint of the front axle and the chassis, with a pair of rigid links connected on either side respectively to the chassis and to the axle by means of ball joints.

7. A vehicle as claimed in claim 5 or claim 6, wherein the rear suspension comprises shock absorbers and springs at each side of the rear axle, which are connected between the axle and the chassis, a V-shaped strut connected to two points on the axle and one point on the chassis by means of ball joints, and a diagonal bracing strut behind the axle connected between the axle and the chassis to locate the axle relative to the chassis.

8. A self-propelled agricultural spraying vehicle substantially as herein described with reference to the accompanying drawings.