GB2344775A - Sprayer/Spreader boom switching means - Google Patents

Abstract

Where agricultural sprayers and spreaders have their distributing nozzles and outlets located on transverse booms, problems arise when the projected track of the machine intersects that of a footpath crossing it if the angle of intersection lies other than at ninety degrees, since the said nozzles and outlets must needs be sequentially switched off, and then on again after the said path has been crossed, if the same is to be kept clear of the product being applied, or large areas be left untreated. The present invention outlines an electronic means of automating such sequential switching, and which same, by isolating the mechanism utilised for switching the said nozzles or outlets back on once the said path has been crossed, allows the same sequential switching means to be used at the beginning and ending of each bout of work, to switch the said nozzle or outlet means, or such pluralities thereof as may be grouped together, on or off, thereby diminishing waste incurred through over and under application of the product being applied, to the benefit of all.

Description

SPRAYER/SPREADER BOOM SWITCHING MEANS This application relates primarily to the field of agriculture, and the control of agro-chemical sprayer distribution nozzles and fertiliser spreader outlets located on transverse booms, whose working widths typically run from 12 to 48 metres, and refers to a previous application 01211 of 1979 by the same applicant, granted as BP No to Curtis Long Developments Ltd.

Many modern fields are amalgamations of several earlier fields and are now crossed by public footpaths which used, in many instances, to follow the original field boundaries. The said footpaths are not, for obvious reasons, sprayed with agrochemicals, the public having unlimited access thereto. Where the said footpath lies at rightangles to the said machine's track all the said nozzles or outlets may be simultanously switched off as the footpath is reached, and on again when it has been crossed. In the present invention a means of automating the sequential switching off of the said nozzles/outlets where a footpath is crossed at an angle other ninety degrees, and sequentially reswitching them on after the said crossing has been completed, is described. It is necessary to take into account the forward speed of the said machine, the angle of intersection of the machine's projected track with the said footpath, the working width covered by each nozzle/outlet or sub-grouping thereof, and the width to be left unsprayed. The process may be simply achieved through electronic means by the electronic inputting of the said machine's ground speed, the machine operator manually pre-setting the width of the footpath, manually inputting the said angle of intersection, and manually activating the stop control as the leading end of the said boom arrives at the switching point. Thereafter the said nozzles are switched off at intervals appropriate to the said speed and angle and sub-division of working width, and on again after the correct distance has been covered to leave the desired manually pre-set path width clear of the product being applied. The said inputs of angle and width may, alternately, be inputted from a digital map employed in conjunction with a geographic postioning means such as the satellite driven Global Positioning System where such a digital map means is employed in the machine control system, and activated thereby.

Where the machine's track is at an angle of intersection of other than ninety degrees with the headland the plurality of nozzles/outlets upon such said booms are normally switched on or off by the operator through the manual operation of a switching means in one of two ways, all together, or sequentially in groups, for example, one quarter thereof at a time. This latter requires the exercise of considerable manual dexterity when the value of the angle is near ninety degrees, and moreover requires it at a time when the operators workload is at it's highest.

The said sub-divisions being coarse, inaccuracies result in sizeable misses or double doses, with possible crop losses from over or under dosage, and wastage of the products applied, all of which represent irrecoverable financial costs. Following crops may be adversely affected by double dosing with some products. There is therefore potential economic loss to the grower on several counts.

In work, the operator of a boomed machine, such as an agricultural sprayer, usually treats the periphery of the field, known as the"headland"first, by going round once, or twice, the vehicle track on the second circumnavigation being a boom's width apart from the first, so treating an area once or twice the working width of the said boom, before beginning to go up and down the field, working in a series of parallel lines or "bouts", each the working width of the said boom, making 180 degree turns on the headland at the end of each bout. Where the track of the said machine lies at ninety degrees to the headland the nozzles or outlets of the said boom may all be switched on or off simultaneously. Where the bout axis is at an angle other than ninety degrees the operator faces the problems above described. Therefore the said switching means above described may, with advantage, be additionally be employed at the beginning and end of each bout, by isolating the means whereby the said nozzle/outlets are automatically switched on after the footpath has been crossed.

For simplicity's sake the said device will be first described hereunder as a headland switching means, and then as a footpath crossing switch.

In figure 1 is a schematic plan showing at XY the track of the said machine proceeding from X to Y, the said boom means symetrically located either side thereof as b, the left side intersecting the headland c, at an angle A. The distance to be covered before the right hand end of the boom crosses line c is shown as a, and may be expressed as: a = b x tan A, where the angle C, as here, is a rightangle, which same formula may be employed to describe any sub-division of the said boom, since the time required to cover the distance a, be it that of the entire boom, as depicted in Figure 1 or any sub-division thereof, is a function of the said working width, and forward speed, or distance over time. This may be inputted by a variety of means, for example micro-wave radar, or Hall effect sensors quantifying the rotational speed of a wheel in conjunction with it's pre-determined rolling radius. In the present invention the input angle, or angle of intersection, of the machine's projected track with the headland may be manually set, or electronically inputted from and by a pre-loaded digital map employed in the said machine's control system operated in conjunction with a geographical positioning system giving the machines real time position on the said map, which same may also be employed for operating the said switching means, both as a footpath switch or as a bout start/stop switch. Where the said angle is manually set the operator is presented with a circular control knob, across whose diameter an easily visible line or bar is marked, as may be seen in Figure 2 at K. In the preferred embodiment thereof the said knob means is mounted beside the operator in such a manner that the said line is at rightangles to the vehicle's fore and aft axis when the angle of intersection, A, is at zero, i. e., the said vehicle's same axis lies at ninety degrees to the said headland, and lies between pointers indicating the same. Where the said angle is at other an ninety degrees the operator turns the said knob in the . quired direction, to align, by eye, the said diametrical line thereon parallel with the said headland c, as perceived, so presetting an analogue value for angle A and thus, given the boom width or that of any sub-division thereof, the distance a appropriate to the same. When the appropriate end of the boom reaches the said headland the said nozzle or outlet means are started or stopped by actuating the appropriate switch,"stop" or"start"as desired, as shown, by way of example, in Figure 2, whereafter each sub-division is sequentially switched, the first immediately, and the remainder as the delay computed appropriate to the said angle, A, measured vehicle speed, and sub-division of width expires, until the full working width, or such sub-division of the whole as may be engaged with the said switching means has been fully switched on or off, as the case in hand requires.

Where the said switching means is employed in footpath crossing mode a nominal value for the footpath width, w, in Figure 1, is manually pre-entered as at W in Figure 2. Where the said switching means is to be manually activated a further switching means as at P in figure 2 is engaged to set the said device in footpath mode. In the preferred embodiment of the manual means clear indication of such engagement is given, by for example employing a press button switching means in which same the said button is illuminated until the footpath has been crossed, and the operation completed, after which the said switch P is automatically disengaged until re-set.

In Figure 1 now let the line c represent the near side of a footpath to be crossed, and the line p-p represent the far side thereof. In the triangle e f w, the angle E is a rightangle, the angle W = (90 degrees less angle A) and the distance to run, e, from which, given the machine's groundspeed, the switching delay, d, between switching off and on, may be computed.

Thus d = w Sin W Having pre-set the width w, as above described, and, where the operation is manually controlled, the angle W, using the knob K, as above described for the headland, but in this case aligning the said bar with the said footpath, the operator switches the boom off by employing the stop switch when the appropriate end of the boom intersects the desired stop line, whereafter the sequential switching off proceeds as above described, the delay d for the distance to run to clear the footpath width commencing it's countdown as the stop switch is used. At the completion of the delay d the said first of the said sub-division of nozzles/outlets switched off is switched on again electronically, with the sequential switching on of the remaining sub-divisions occurring successively in the same manner as that at which they first switched off when the footpath was encountered. Where a geographic positioning system is used in conjunction with a pre-loaded digital map means the said angle W, and the value of w may be electronically determined as above described, and the device activated by the same means.

Claims (5)

1. CLAIMS Wnat I claim is: 1. The employment, in an agro-chemical sprayer or fertiliser distributor having a plurality of distribution nozzles or outlets transversely mounted on a boom means, of a switching means controlling the said individual nozzles or outlets, or sub-grouped pluralities thereof, for the purpose of turning them on or off sequentially, utilising a computing means after the manner outlined in the text and Figure 1 of the accompanying application which, given : ... the angle of intersection of the said machines projected track with a footpath or other area lying in it's future track, which is to be left untreated, is lying at an angle other than a rightangle ... an input of groundspeed, ... the number and working width of the sub-divisions of the said boom means being switched, ... and the width of the footpath or other area (hereafter described merely as"footpath") to be kept clear of the product being applied by the said boom means to calculate, with reference to Figure 1 of the accompanying application firstly: the value of a where a = b x Tan A secondly: the value of d where d = w Sin W and W = (90 degrees less A) for the purpose of computing: by virtue of the first equation above, the delay required between switching the first such said working sub-division off and the second thereof being switched off, and so on successively along the said boom, as the said footpath is reached by each respective sub-division, and to initiate the said switching at the completion of each such said interval, and by virtue of the second equation the delay required to run he distance necessary for the first such said sub-section to clear the said footpath as above described, before the said first such sub-division may be switched back on, and to intiate the same, whereafter the remainder are successively switched at the appropriate intervals as above described for their switching off.
2. 2. The employment of a manually operated means of entering the said angle of intersection of the said footpath with the machine's projected track, by setting the same through the turning of a control knob having a clear line or bar across it's diameter, such that the same lies transversely across the said knob aligned between between pointers when the said angle lies at zero, and when turned, in either direction, until the said bar is perceived by the operator to lie parallel with the footpath thereby sets an analogue value for the said angle of ntersection with the same.
3. 3. The employment of a manually operated switching means in the control apparatus whereby the device is engaged in"footpath mode", in a clearly visible manner, before the same is encountered, and which self cancels after the said footpath has been crossed, and all the said sub-divisions on the boom means have been reactivated, thus leaving the said sequential switching means free to employ for the purpose of turning the said sub-divisions on and off at the beginning and end of each successive bout of work.
4. 4. The electronic inputting of the data relating to the width of a footpath to be crossed, and the angle of intersection of the projected track of the moving machine with the said footpath crossing the same, by digital means, from a digital mapping means utilised in the machine's control system in conjunction with a geographical positioning system, and the activation of the said switching means according to claim 1 above, by the same digital means for the purpose of leaving the footpath unsprayed through turning the said nozzles or outlets or such sub groupings of pluralities thereof as may be employed, both off and on.
5. 5. The electronic inputting of the data relating to the angle of intersection of the projected track of the moving machine with a headland boundary at which spraying is either to start or stop, and the activation of the switching means above claimed by the same digital means as cited in claims 3 and 4 above, for the purpose of stopping or starting the work in hand.