GB2129663A - Spraying unit - Google Patents

Abstract

A proportional dosing unit for mounting on a vehicle comprises a) a pump; b) means for actuating the pump; c) as control for the pump actuation means, an impulse fractionator receiving pulse signals from a part of the vehicle which rotates at a speed proportional to the forward speed of the vehicle or by means of an electrical impulse from a radar speed detecting device; d) means for supplying liquid pesticide from a reservoir to the inlet of the pump; e) means of injecting the pesticide leaving the exit of the pump into a fluid supply; and f) means for conveying the mixed pesticide/fluid supply to dispensing points on the vehicle.

Description

SPECIFICATION Spraying unit The present invention relates to a spraying unit for use, mounted on a vehicle, in controlling pests.

There is a real need to find a method for effectively applying a pesticide to specific pest-infested areas. A particular example is the need to control the growth of weeds in the kerb and channel zones of public highways. Many attempts have been made to adapt herbicide treatments to existing mechanical road sweeper vehicles. For example, the direct addition, into the water supplies, of herbicides in the form of wettable powders or solid materials such as sodium chlorate has been investigated.However, such direct addition of powder-form herbicide has encountered difficulties such as: a) sodium chlorate has caused corrosion in the vehicle watertank and elsewhere on the vehicle; b) wettable herbicide powders settle out in the vehicle watertank and cause blockages resulting in patchy, uneven applications; and c)thewaterfrom the vehicletank is used for other purposes, e.g. damping down dust ahead ofthe mechanical brush, so that much ofthe herbicide added to the vehicle watertankwas never actually in contact with the weeds to be treated.

With the advent of liquid herbicides, units were developed which were capable of overcoming the existing problems associated with the use of solid herbicides. For example, a spray unit was developed which comprised a pump capable of handling a concentrated liquid herbicide, and means for providing a water supply which was separate from the main watertankand which was used for mixing with the liquid herbicide.

These further units were disadvantageous, however, in the following respects: a) they provided an inadequate range of efficient application of herbicide when the forward speed of the vehicle was varied; b)theylacked automatic calibration; c) they did not effect adequate mixing of herbicide and water; and d) they required the use of an invertorto step upthe currentfrom 12 volts to 240 volts.

It is therefore, an object of the present invention to provide a spray unit which overcomes the disadvantages associated with known spray units used in conjunction with liquid herbicides.

Accordingly, the present invention provides a proportional pesticide dosing unit for mounting on a vehicle and comprising: a) a pump; b) means for actuating the pump; c) as control for the pump actuation means an impulse fractionator receiving pulse signals from a part ofthe vehicle which rotates at a speed which is proportional to the forward speed ofthe vehicle, or by means of an electrical impulse from a radar speed detecting device; d) meansforsupplying liquid pesticide from a reservoir to the inlet ofthe pump; e) means for injecting the pesticide leaving the exit of the pump into a fluid supply; and f) means for conveying the mixed pesticide/fluid supplyto dispensing points on the vehicle.

While the pump may be e.g. a peristaltic metering pump, it is preferably a corrosion-resistant hydraulically operated double diaphragm chemical injector having a preset stroke adjustment. Ath ree-way direct-acting solenoid valve connected to the vehicle battery provides an eminently suitable means for actuating the pump.

The impulse fractionator used as a control for pump actuation may receive pulse signals e.g. from a sensor/transducersignal meansattachedtoagear box, propellor shaft or power take-off.

Preferred means for supplying pesticide from a reservoirto the pump inlet is via a rigid probe atthe base of which is a filter and a foot valve.

Conveniently, the means for conveying the pesticide/fluid to dispensing points (preferably spray nozzles adjustable for height and width) on the vehicle is either a rigid boom assembly or a flexible hose arrangement which includes a baffled mixing chamber in order to ensure efficient mixing.

The invention will befurtherillustrated by reference to the accompanying Figures 1 and 2.

Figure lisa line drawing ofthe individual components ofthe pesticide dosing unit according to the invention in which lisa hoseproof control box with isolating switch and plug/socket connectors for a 12 volt direct current power supply (1), a solenoid valve coil (3) and a pulse sensor (4). 5 is a cage for duty and standby chemical containers, the duty container having an injector suction tube assembly (5A) with footvalve/strainer (5B). 6 illustrates a pressure tap-off valve assembly from the pump (7) discharge, (7) being a type HD 4P chemical injector (Russell Fluid Control Limited). 8 is an on-stream static mixer and 9 is an injector pilot solenoid valve 10 is a solution spray nozzle and ball joint adjustment and 11 is a solution spray lance and angle/height adjustments.

Figure 2 is a line drawing ofthe individual components of the pesticide dosing unit according to the invention mounted on a mechanical road sweeper. In Figure 2, components 1 toll have the same significance as in Figure 1 and 12 shows the vehicle spray pump and 13 is the vehicle auxiliary diesel engine.

In operation, according to the specific embodiment illustrated in Figures 1 and 2, the sensor4 picks up a signal taken off e.g. the prop shaft of the vehicle, and transmits a pulse into the control box (1). The solenoid valve coil (3) picks up the pulse transmitted into control box (1) and coil (3) is energized. As a consequence, fluid from the main fluid source on the vehicle is allowed to energize the diaphragm ofthe pump (7) which, in turn operates the piston ofthe pump (7) which delivers a one-stroke dose into the static mixer (8). The pesticide and fluid are mixed in mixer (8) and conveyed on to spray nozzles (10).

In an alternative embodiment, in the case of vehicles having inadequate fluid pressure,the pump (7) may be actuated by a seperate hydraulic line (not shown).

Each of the components of the dosing unit are preferably constructed of corrosion-resistant materials e.g. synthetic polymers or stainless steel since the unit is desirably mounted outsidethevehicle cab for reasons of health and safety.

The new dosing unit may be em ployed mounted on any vehicle adapted for dispensing pesticide on to pest-infected areas. Examples oftypical vehicles include agricultural tractors and mechanical road sweepers.

While the new dosing unit may be used in conjunction with any liquid pesticide e.g. herbicides, insecticides and fungicides, particularly suitable are, as herbicides, Dicurane 500L, Gesaprim 500 L Gesatop 500 L, Hytane 500 L, Malet 50 EC, Mofix 500 L, Opogard 500 L, Prebane 500 L, Semeron 250 L, Stellox 40 EC and Swipe 250 SCW; as insecticides, Dicron 45 SC, Fenitrothion 50 EC, Primatol 500 L, Sapecron 24 EC and Supracide 40 EC; as a fungicide Tilt 250 EC.

Dioron, Dicurane, Gesaprim, Gesatop, Hytane, Mofix, Opogard, Prenane, Primatol, Sapecron, Semeron, Stellox and Supracide are registered Trade Marks of CIBA-GEIGYAG, BasleSwitzerland.

The rate of application ofthe pesticide will vary, e.g.

accordingly to the particular formu lation used and to the type of appiication viz. agricultural or industrial. As a general guide however, the pesticide may be applied art a rate of 0.5-40 litres per hectare, more preferably 2-10 litres per hectare.

Advantagesofthe new dosing unitofthe invention include its wider range of efficient pesticide application at different forward speeds; its automatic calibration; the preferred use of a mixing chamberto ensure more efficient mixing of pesticide and water; provision of all plumbing necessaryto mounting on the vehicle including the preferred adjustable spray nozzle; and provision of a pump which uses directly a 12 volt battery supplywhich sweather-proofand tamper-proof and which is pre-setto provide dose levels consistentwith the forward speed ofthe vehicle.

Claims (7)

1. A proportional dosing unitfor mounting on a vehicle and comprising a) a pump; b) meansfor actuating the pump; c) as control forthe pump actuation means, an impulse fractionator receiving pulse signals from a part of the vehicle which rotates at a speed proportional to the forward speed ofthe vehicle or by means of an electrical impulsefroma radar speed detecting device; d) means for supplying liquid pesticidefrom a reservoirtotheinletofthe pump; e) means for injecting the pesticide leaving the exit ofthe pump into afluid supply; and f) means for conveying the mixed pesticide/fluid supplyto dispensing points on the vehicle.

2. A unit according to claim 1 wherein the pump is a hydraulically-operated double diaphragm chemical injector having a pre-set stroke adjustment.

3. Aunitaccording to claim 1 or2whereinthe meansforactuating the pump is a three-way directacting solenoid valve.

4. A unit according to any of the preceding claims wherein the means for supplying pesticidefrom a reservoirto the pump inlet is-via a rigid probe at the base ofwhich is a filter and foot valve.

5. A unit according to any ofthe preceding claims wherein the meansforconveying the pesticide/fluid to dispensing points on the vehicle is either a rigid boom assemblyoraflexible hosearrangementwhich includes a baffled mixing chamber in order to ensure efficient mixing.

6. A unit according to claim 5, wherein the dispensing points are spray nozzles adjustable for height and width.

7. A unit according to claim 1 substantially as described, and as illustrated in either of the attached Figures 1 and 2.