GB1583794A - Crop spraying apparatus - Google Patents

Description

(54) IMPROVEMENTS RELATING TO CROP SPRAYING APPARATUS (71) We, R.D.S. (Agricultural) Limited, a British Company, of Stroud Road, Nailsworth, Gloucestershire, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement : This invention relates to crop spraying apparatus.

A common form of crop spraying apparatus is tractor-mounted or self propelled with several booms, two or more of which can hinge out to either side of the tractor and another one, generally shorter than the others, spans the rear of the machine. It is important, for economy and efficiency, that the spray fluid should be delivered in a quantity to give the desired spread over the ground. To ascertain volume per unit area, the fluid flow, the vehicle speed and the effective working width must be known. The latter two are easily determined and translated into an electrical signal, but fluid flow transducers of the necessary accuracy are expensive.

According to the present invention there is provided multiple boom spraying apparatus wherein the booms are fed with spray material from a common source via respective branch conduits, wherein a flowmeter is fitted in one only of said conduits so that the contribution from one boom is measured, and wherein information on the total amount being sprayed is derived from means receiving a signal from the flowmeter and adapted to scale up that signal in accordance with the proportion of the spray contributed by said one boom to the whole.

Conveniently, the scaling-up means also receives a signal indicative of the speed of a vehicle carrying said apparatus and is adapted to determine the amount sprayed per unit distance travelled or per unit area traversed.

For a better understanding of the present invention, one embodiment will now be described, by way of example, with reference to the accompanying drawing in which the single Figure is a diagram of multiple-boom spraying apparatus.

The multiple-boom apparatus is mounted on a vehicle (not shown) and has a tank 1 of spray material from which fluid is drawn by a pump 2. This delivers to three booms 3, 4, 5 via a valve 6 and respective branch pipes 7, 8, 9. A return 10 runs from the valve 6 back to the tank. The function of this is to return excess flow, caused by the pressure setting and pump output, back into the tank. The pressure setting is determined by adjuster 11 and indicated on dial 12. A flowmeter in circuit between the tank 1 and valve 6 would not always give a correct indication of fluid actually being sprayed; it would read too high whenever the valve was returning fluid to the tank.Of course, a further flowmeter could be fitted to the return 10 and a subtraction made, or a flowmeter could be fitted in each boom pipe 7, 8, 9 and the flow added, but these would add substantially to the cost and complexity.

A single flowmeter 13 is therefore fitted in one of the branch pipes, 7, and its output is multiplied by an appropriate factor in multiplier 14 to represent the flow to the full complement of booms. For example if the side booms of a three boom machine have ten spray nozzles each and the central boom three, and the flowmeter is in the conduit to one of the side booms, as shown, the multiplying factor will be 23. This can then be used in divider 15, in conjunction with a vehicle speed signal from detector 18, to indicate volume sprayed per unit distance travelled. Since the booms have known constant span, the calibration of an indicator could equally well give volume per unit area. Alternatively, the speed signal may be multiplied by a factor corresponding to the spread of the booms to give a signal corresponding to the rate of area covered.This is then used to divide the volume rate signal.

If a volume rate signal is not required for the full complement of booms, the multiplier 14 may be arranged after the divider 15.

The result can be used simply to measure and indicate the rate of spray application or it can be used to govern the delivery of the spray material in accordance with the vehicle speed to maintain an even spread.

For example, it would control the valve 6 or, if a variable delivery pump were used, it would govern that.

WHAT WE CLAIM IS:- 1. Multiple boom spraying apparatus wherein the booms are fed with spray material from a common source via respective branch conduits, wherein a flowmeter is fitted in one only of said conduits so that the contribution from one boom is measured, and wherein information on the total amount being sprayed is derived from means receiving a signal from the flowmeter and adapted to scale up that signal in accordance with the proportion of the spray contributed by said one boom to the whole.

2. Apparatus as claimed in claim 1, wherein the scaling-up means also receives a signal indicative of the speed of a vehicle carrying said apparatus and is adapted to determine the amount sprayed per unit distance travelled or per unit area traversed.

3. Apparatus as claimed in claim 2, wherein the output of the scaling-up means is arranged to govern the delivery of the spray material to maintain an even spread.

4. Multiple boom spraying apparatus substantially as hereinbefore described with reference to the accompanying drawing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (4)

**WARNING** start of CLMS field may overlap end of DESC **. multiplier 14 may be arranged after the divider 15. The result can be used simply to measure and indicate the rate of spray application or it can be used to govern the delivery of the spray material in accordance with the vehicle speed to maintain an even spread. For example, it would control the valve 6 or, if a variable delivery pump were used, it would govern that. WHAT WE CLAIM IS:-

1. Multiple boom spraying apparatus wherein the booms are fed with spray material from a common source via respective branch conduits, wherein a flowmeter is fitted in one only of said conduits so that the contribution from one boom is measured, and wherein information on the total amount being sprayed is derived from means receiving a signal from the flowmeter and adapted to scale up that signal in accordance with the proportion of the spray contributed by said one boom to the whole.

2. Apparatus as claimed in claim 1, wherein the scaling-up means also receives a signal indicative of the speed of a vehicle carrying said apparatus and is adapted to determine the amount sprayed per unit distance travelled or per unit area traversed.

3. Apparatus as claimed in claim 2, wherein the output of the scaling-up means is arranged to govern the delivery of the spray material to maintain an even spread.

4. Multiple boom spraying apparatus substantially as hereinbefore described with reference to the accompanying drawing.