GB2141912A - Agricultural spraying apparatus - Google Patents

Abstract

Substantial penetration of dense foliage by sprays, and under-leaf cover are obtained by an apparatus that consists of a specially designed or adapted vehicle which carries and services an aerial module by which the actual spraying is carried out. The module is lifted, propelled and directed by a rotor having ram-jets at or near the tips, the whole being so arranged and constructed so as to operate in a safe manner at very low speeds and by its design, to produce a pattern of descending and intermittent vortex filaments in which the spray is entrained and by which it is carried into and distributed within the crop. The spraying system is mounted on the aerial module ahead of this induced airflow so that the very small droplets will be safely carried into and contained within the crop. <IMAGE>

Description

SPECIFICATION Agricultural spraying apparatus This invention provides spraying apparatus of agricultural equipment standard which produces penetration and underleaf cover of dense vegetation while not damaging crop or soil resultant from vehicular contact.

Spraying of crops, hitherto, has been divided into two distinct catagories, namely, spraying from ground equipment which is normally carried out by farmers themselves and spraying from the air which is normally carried out by operators of specially modified or designed aircraft or helicopters. In both cases, no appreciable penetration of the crop canopy of dense crops or appreciable underleaf cover have been obtained.

Although experiments using fans mounted on ground equipment have been reported these have not been successful and it is not the purpose of this invention to follow that line of endeavour.

Ground spraying, while cheaper, has many disadvantages consequent on the difficulty of traversing dense vegetation without damage to the present or future crops through contact with the crop and soil, to the point where it is often impossible to spray, e.g. due to waterlogged ground or over rough areas. The present invention combines the cheapness and availability of ground equipment with the flexibility and freedom from crop damage of aerial application while providing a hitherto unobtainable but highly desirable capacity for substantial penetration and underleaf cover. Other advantages which are part of the intention of the invention are also mentioned.

The invention consists of a ground vehicle, with an aerial module, the ground vehicle being a piece of farm machinery which is specially designed or adapted to carry the aerial module from which the actual spraying is accomplished. The vehicle has, in addition to the usual means for moving from place to place, means for launching, recovering, storing, servicing and transporting the aerial module, these being respectively.

(a) a flat, unobstructed platform which can optionally be ievelled by means of levelling activators attached to either the platform or the vehicle.

(b) Markings on the platform and indicator lights which assist the pilot of the aerial module in aligning and landing onto the platform.

(c) Clamps and supports for the module and the rotor while in transit.

(d) Tanks, pumps, metering valves and meters and the necessary connections for supplying the module with fuel and spray materials except that other tanks mounted on adjacent vehicles may also be used if desired.

The aerial module, which is an integrai and essential part of the invention, consists of a cabin for the pilot in which are the controls and instruments, fuel and spray tanks, pumps valves, and spray dispensing equipment mounted in the manner described below and shown in the example illustrations. The above assembly is lifted, propelled and directed by a preferably two bladed rotary wing which is driven by tip mounted ram jets, one on each blade, near or at the tip. These ram jets are an essential part of the invention and play an essential role in the safety, operation and economy of the invention as well as in the airflow patterns that achieve the major object of the invention, namely penetration and underleaf cover of thick foliage crops.Additionally the aerial module has a small commercial engine for starting purposes and a small tail rotor for yaw control purposes.

The invention is contrived to be used in a specific manner, this being the method by which the penetration is achieved. The aerial module operates, while spraying, at a speed below the speed at which the flow pattern from the rotor changes from a series of discrete skewed helical vortex filaments originating from each blade tip, into two rolled up vortecies trailing from each side of the rotor, this speed being typically about 50 km/hr, and at a height of up to about 10 metres. The spray distribution equipment is placed ahead of the above mentioned downwash pattern such that the droplets are entrained in the intermittently passing vortex filaments as they descend and enter the crop where the vorticity is broken up and serves to distribute the spray material homogeneously through the crop.

Prolonged operation in the manner described above is made acceptably safe by the inherent safety, stability and controlability after single 'engine' failure when operating in what is called the 'avoid curve' of normal helicopters, which is a result of the module's inherent 'twin-engine' configuration, the fact that it has no engines as normally thought of but only extremely simple ram-jet combustion chambers having no moving parts, and the resulting high rotor inertia.

The safety features described above, taken together with the restricted area of flight, being only within a few hundred feet of the ground at most, within a few miles of its service vehicle, always over agricultural land and - by the nature of its intended purpose -- always operated in good weather will mean that it will be operated by essentially agricultural workers having a special licence much like that of a tractor driver's licence at present. Another feature of the invention is that it is of the sort whose operation, maintenance and general handling can safely be accomplished in an agricultural environment.

Indeed, due to the slow speed of operation, its inherent safety features and operation from a base immediately adjacent to the area of operation, the aerial module will be appreciably safer to operate than any present aerial application vehicle and this is an important feature of the invention: The spray equipment is composed of nozzles or other droplet generating devices distributed, as has been said, across the width of the rotor and ahead of it on a suitably contrived boom such that the droplets produced are entrained across the width of the rotor by the rotor flow pattern described. The flow rate will be appropriate to the low speeds, being much lower than normal since normal operation consists of traversing as fast as possible in order to increase productivity.The flow rates will also be much lower due to the much reduced requirement for spray material consequent upon the achieving of substantial penetration. Droplet sizes will also be much lower than normal, generally in the Low Volume (LV) and Ultra Low Volume (ULV) ranges, this being possible due to the entrainement and penetration of the spray with much reduced possibility for drift. Thus the spray equipment will be special and no presently available or used system will be usable. These substantial gains in spraying efficiency, reduction in spray materials used and reduction in risk of damage due to drift are a major feature of the invention.

Other features of the aerial module are the enclosure and pressurization of the cabin with filtered and conditioned air in order to safeguard the pilot and the use of corrosion resistant composite materials.

Due to its inherent safety, the equipment may also be used at night, when suitable conditions are more frequently present, and for this purpose it would be equipped with an infra-red night viewing system where the illumination would come from the ram-jets themselves. This is a particular advantage of this invention.

A further advantage of the invention is that the aerial module has a very low empty weight and a very high lifting capacity together with being road mobile and operating only over a restricted distance from its vehicle. It also has instant starting capacity in any weather and may be left unattended for long periods without deleterious effects. The aerial module would be fitted with a detachable cargo hook and the invention used in such areas as aerial crane work, fire fighting and rescue, where in each case the complete vehicle would first arrive at the scene of operation (such as happens with a crane or fire appliance) and then the aerial module would be used under local control as required. This constitutes a new and improved appliance for the above mentioned operations of aerial crane, fire fighting and rescue work.

The figures below illustrate a possible configuration of the invention.

Figure 1 is a general view in the transportation configuration.

Figure 2 shows the equipment in its operating configuration.

Figure 3 shows the aerial module in the process of spraying, showing the invisible but specially generated airflow which is the heart of the invention and on which the penetration and underleaf cover depend.

Figure 4 is a top view of Figure 3 and depicts the lines of intersection of the rotor generated airflow, the spray droplets and the ground.

Referring to Figure 1, in the present example, the vehicle 1 has a cab 2 for normal transit from place to place. On its roof are mounted landing guidance lights 3 and a foldable blade support 4.

The body of the vehicle contains tanks for spray fluid, fuel and water 5 as needed over which is a platform 6 which can be raised for operations. At the rear of the vehicle there is a compartment 7 which houses the controls, valves, meters and pumps for servicing the aerial module during operations and on it is mounted a second foldable blade support 8. The aerial module 10 rests on the platform 6 and is held there during transportation by the clamps 9. It is described in greater detail together with Figure 2. The spray gear 11 is folded back for transportation.

In Figure 2, the platform 6 has been raised to its operating height and extensions added all round to make a suitable landing pad. Connections from the vehicle to the module for transferring fuel and spray fluids are not shown for clarity. The aerial module has a cabin 13, tanks for spray material and fuel 14 and a compartment housing the starting engine, pumps for spray material and air, filters, meters and valves, 15, each shown diagrammatically only. It has two blades 1 6 each with a ram-jet unit at the tip 1 7 and a tail rotor 1 8 for yaw control. The spray bar 1 9 is set forward of the module body on a boom 20 (see also Figure 4) in order to be ahead of the intermittently passing vortex filaments (see Figure 3) and thus permit the spray to be entrained by them as they pass downwards into the crop.

Figure 3 shows the module in operation. The discrete vorticies are depicted originating from each blade tip, 17, and being convected downwards in the general airstream shown by the curved arrows 22. The droplets from the spray boom 23 are overtaken by these vortex filaments 21, which have a much higher internal velocity than the general 'downwash' 22, are entrained by them and carried by them into the crop 24 where the drops and vorticity are uniformly dispersed, 25.

Figure 4 shows, in plan view, the module 10, blades 1 6 and rotor disk 26, the spray bar 1 9 and forward projecting mounting boom 20. 27 shows approximately the line where the spray droplets are entrained by the downward convecting vortex filaments while 28 depicts the approximate pattem the downwash would make with the ground.

Claims (9)

1. Agricultural spraying apparatus comprising a vehicle which is specially designed or adapted to carry, launch, retrieve and service a special aerial module which is constructed by the use of ramjets at the blade tips so as to be safe for operation in the 'avoid curve' of standard helicopters and which carries a special spraying system of flow rate and droplet size appropriate to an unusually slow operating speed and to substantial penetration of thick foliage which in turn is achieved by mounting the spraying bar so far forward ahead of the rotor through flow that the droplets are entrained by the following discrete vortex pattern which has been intentionally generated by the module's design and slow speed of operation and which carries the droplets into the crop, homogeneously distributing it within.

2. Apparatus as above in Claim 1 except that the vehicle may be self-propelled or be a trailer drawn by another vehicle and it may have a raising platform as shown in the example or not.

3. Apparatus as in Claims 1 and.2 where the transport vehicle has tanks, pumps, meters, valves and controls for servicing the aerial module with fuel and spray material in any combination, those items not being mounted on the vehicle being provided on other vehicles.

4. Apparatus as in Claims 1, 2 and 3 where the vehicle has means of holding down the aerial module and for supporting the blades during transportation.

5. An aerial module as mentioned in Claims 1, 3 and 4 having the following essential features.

(a) Two or more blades of a rotor, mounted above, where each blade has a ram-jet at or near the tip and is designed for operation at slow forward speeds and to produce the required blade tip generated vortex.

(b) Operation at a speed below that at which the specially generated tip vortices mentioned in Claim 5(a) change from a discrete skewed helical pattern as illustrated in Figure 3 to a pattern of two 'rolled-up' vorticies trailing substantially in a straight line backwards from each side of the rotor disk, this speed being typically less than 50 km/hr.

(c) A spray system mounted sufficiently far forward so that the droplets which are generated across the width of the rotor are entrained by the following intermittent vortex filament pattern as it descends into the crop as illustrated in Figures 3 and 4, at the low speeds mentioned in Claim 5(b) above.

(d) A spray system capable of giving flow rates and droplet sizes appropriate to the slow speed of operation and to substantial penetration, these being respectively in the Low and Ultra Low Volume range of droplet sizes and rates of a tenth or less of standard rates for present systems.

6. An aerial module having the features of Claim 5 and having a cabin with controls and instruments for the pilot that is enclosed and 'pressurized with filtered air, tanks for fuel and spray material, a starting engine, pumps, valves and controls for the spray system and a tail rotor for yaw control.

7. A vehicle as in Claims 1 to 4 inclusive having indicator lights to assist in landing the aerial module.

8. Agricultural spraying apparatus substantially as described in the example and depicted in Figures 1 to 4 inclusive.

9. Apparatus as described in Claims 1 , 2, 4, 5(a) and 6 but fitted with a cargo hook for use as an aerial crane.