GB2087702A - Apparatus for applying chemicals to weeds and plants - Google Patents

Abstract

A boom for applying chemicals to plants comprises a plurality of reservoirs (10) each in the form of a length of tubing adapted to serve as a reservoir for liquid chemical and having apertures in a wall thereof through which a plurality of wicks (12) extend for exposure to plants. The boom is adapted to be carried by a tractor to extend transverse to the direction of motion to wipe chemicals from the wicks onto plants. The ends of the reservoirs may be closed by end caps (14), or internal walls may divide the interior of the tubing into short lengths to prevent undue variations in liquid level upon tilting of the boom. In this way problems hitherto encountered during use on sloping ground are overcome. <IMAGE>

Description

SPECIFICATION Improvements in and relating to methods and apparatus for applying chemicals to weeds and plants This invention relates to apparatus for applying chemicals to plants such as crops and weeds and to a method of using such apparatus.

It is known to apply herbicides and other chemicals to weeds or plants growing in a field by drawing apparatus across the field with exposed wicks at a pre-determined height and disposed so as to make contact with and moisten. selected plants according to height. The invention is particularly useful for ridding a crop of bolted vegetation which normally grows to a greater height than the remainder of the crop.

United States Patent Specification 4187638 describes one form of such an applicator. The device comprises generally hollow tubular member having a plurality of elongate wicks extending therefrom and having drainage and filling apertures which are normally closed. The device is mounted on a suitable frame and towed or pushed by a tractor or like vehicle so that the wicks are dragged over and in contact with growing plants.

Whilst this design of applicator has certain advantages over those of earlier designs described in prior art mentioned in the specification 4187638 the design still has some drawbacks.

One drawback which is quickly observed in use on ground which is other than flat and generally horizontal is that the liquid tends to swill to one end or the other of a long boom when the latter is moved across undulating or generally sloping land unless the boom is always traversing the land perpendicularto the line of the slope.

It would be appreciated that the boom cannot be levelled in any conventional manner since to do so would mean that one end would necessarily be lower than the other and would touch plants with the liquid which otherwise should remain free of the liquid.

It is one object of the present invention to overcome this drawback.

It is also difficult to determine whether a boom is filled to the correct level and to this end another objective of the invention is to allow the liquid level within the boom to be monitored.

It is a further object of the present invention to allow a long boom to be transported more readily.

It is a still further objective of the present invention to increase the area of wick presented to a growing crop for a given width of boom and to provide a boom in which the liquid level is maintained at a constant proportion of the interior of the boom.

According to one aspect of the present invention apparatus for applying chemicals to plants comprises a length oftubing adapted to serve as a reservoirforthe chemical and having apertures in the wall thereof through which a plurality of wicks extend for exposure to the plants wherein at least one end of the said length of tubing is adapted to be fitted to a corresponding end of a similar length of tubing to form a boom having twice the length of each of the individual parts.

Preferably the ends which are to be fitted together are squared.

Means may be provided for circumscribing annular end regions of the two abutting lengths of tubing so as to hold the two lengths tightly.

Alternatively male and female joint means may be provided in the respective ends of the two tubes which can be fitted together and locked into position for example by way of rotation or by way of a sliding fit.

Preferably the joint between the two abutting ends of the tubes does not extend radially beyond the circular cross sectional area of the two tubes.

Preferably both ends of each tube are so adapted so that three or more such tubes may be fitted together to form an elongate boom the length of which is a multiple of the individual length of each unit of tubing.

Preferably the join between adjoining lengths of tubing is bridged by at least one wock and preferably the pattern of apertures is arranged such that once the two tube units are joined together, and the requisite links have been made using the wicks, there is no interruption in the pattern of exposed wicks overthe external surface ofthetubes.

Preferably the tubes are of generally circular cross-section and are formed from plastics material.

According to a further preferred feature of the invention each of the standard or unit lengths of tubing is closed off at each end so that there is no ten deny for liquid in the overall boom to swirl or rush all to one end or the other due to inclination of the boom from the horizontal.

According to another aspect of the present invention where each individual unit length is greater than a fixed dimension such as 0.5 metres, the length of the interior of the reservoir is divided by one or more internal walls to divide up the interior into short lengths. Preferably the internal walls completely close off the interior of the tubing on one side from that of the other side of the wall.

According to another aspect of the invention the ends of each pipe length are closed by means of flash fitting end caps.

According to another feature of the invention the boom is at least in part supported by brackets which are located at the joints between adjoining aligned lengths of the tubing.

In one embodiment the brackets are replaced by a right angle support frame of metal or the like and the pipe is supported on a horizontally forwardly extending limb and to the rear by an upwardly extending limb of the right angle section. Retaining straps, members or locking devices are provided for retaining the lengths of pipe on the frame.

Preferably the end caps are axial extensions of the tube and are formed from or include transparent sec tions to constitute windows. In this way the liquid inside the tube can be viewed at all times to check for the level.

According to another feature of the invention, semi-permanent joining means is provided between adjoining lengths of tubing to form single longer length pipes. To this end for example screw threaded joining members may be provided for securing adjoining lengths together.

According to another method of mounting the standard short lengths of tubing are each supported by one or more brackets which themselves are carried by a support frame or arm which is adapted to extend at an angle relative to the direction of movement of a wheeled vehicle such as a motorised vehicle tractor or trailer.

According to a particularly preferred feature of this aspect of the invention, adjoining sections of the length of tubing may be hinged relative to one anotherto allow for example end sections of a multiple section boom to be hinged backwards or forwards or upwards or downwards to reduce the overall width of the boom to facilitate thetransportion of the vehicle carrying the boom assembly through restricted access gateways, openings and along roads.

The relative movement of the end sections of the tubing may be achieved using hydraulic or pneumatic rams or by mechanical linkages.

It is to be understood that this feature of the invention is not limited to an arrangement of which only two end sections at extreme ends of the boom assembly are hingeable but in which four or more sections are relatively hingeable.

However, many sections are relatively hingeable, an appropriate number of hydraulic of pneumatic rams or mechanical linkages may be provided for retracting or extending the different relatively hingeable sections of the overall boom assembly.

According to anotherfeature of the invention, the boom is formed from a plurality of relatively short lengths of closed tubing each constructed in accordance with the first aspect of the invention and each being carried from a point substantially midway along its length from a boom assembly itself adapted to extend at an angle relative to the direction of movement of a wheeled vehicle such as a tractor motorised vehicle lorry or trailer.

Typically the boom assembly extends transversely relative to the direction of movement of the vehicle and preferably each of the short standard lengths of tubing is pivotally mounted relative to the transversely extending boom support member and is adjustable relative to the boom assembly so as to extend therefrom by a more or less acute angle.

It will be seen therefore that the wicks which extend in a generally axially parallel direction along the external surfaces ofthe standard lengths of tubing can be presented more or less acutely to the crop or other plants to which the chemical is to be applied. When the individual lengths oftubing are located substantially parallel to the boom support member the wicks are located at substantially broadside to the plants but in doing so only the thickness of each wick passes over a plant. On the other hand with the length of tubing turned through approximately 30 to 459 a component of the length of each wick is also presented to each plant so that each is inturn in contact with a wick or portion of a wick for a greater length of time and is thus more adequately smeared with the chemical with which the wick is saturated.

In another embodiment the boom is formed from two relatively pivotable lengths of tubing each constructed in accordance with the first aspect of the invention and each of which is pivotally attached to a forwardly extending strut for arcuate movement about a generally vertical common axis and hydraulic or pneumatic ram means or a mechanical linkeage is provided for pivoting the two lengths of tubing outwardly so as to become more transverse relative to the direction of movement of the vehicle to which the strut is attached or can be retracted inwardly so as to extend less transversely.

In a further embodiment of the invention, each of the lengths of tubing is supported for rotation about an axis which may correspond to the axis of the pipe or may be offset therefrom. By rotating the pipe so the head of liquid above the wick may be varied and if required the wick can be raised completely above the level of the liquid within the tube to reduce the risk of unwanted seepage, evaporation and dripping.

The tubing may be rotatable by means of a mechanical linkage or Bowden cable or by means of hydraulic or pneumatic cylinders acting through crank arms and the like or by drive means from a hydraulic pneumatic or electric motor or by a simple manual adjustment for example using wing nuts and an arcuate slot in a flange plate associated a support for the tube.

According to another feature of the invention, each of the tubes may be provided with venting and filling apertures.

According to a particularly preferred feature ofthe invention, the venting and filling apertures may be combined into a single aperture containing a oneway valve so that, whilst liquid can pass into the interior of the tubing no liquid can flow in the reverse direction.

Preferably the one-way valve is associated with a level sensitive device so that when the liquid level within the tube exceeds a given level the subsequent inflow of liquid into the tubing is prevented.

Where a filler and vent aperture is provided, it is preferably located substantially mid-way between the ends of the tubing.

One embodiment of a one-way valve and shut-off valve comprises a floating ball valve in which a floating ball is held captive within a cagethrough which water and air can pass and a seating is provided against which the ball is forced with rising liquid levels either due to movement of the liquid within thetubing orals a resultofoverfilling.

According to a further aspect of the invention, a common feed may be provided to each of a plurality of separate lengths of tubing each sealed from the other so as to form an elongate array of tubular reservoirs from which the wicks extend and the common tubing serving to maintain a supply of liquid to each of the tubes is supplied with the liquid chemical from a constant head so as to maintain the level of the liquid within the tubular reservoirs substantially constant.

Conveniently each of the filler vent holes is threaded and blocked off by a 'T'-piece having a downwardly extending filler/vent tube which communicates with a cross piece in the form of another tube which is adapted to be fitted to flexible hose or the like extending between it and adjoining 'T'pieces.

By feeding the liquid in from one end, only one end 'T'-piece need be blanked to prevent loss of liquid from the far end of the feed line.

If it is necessary to vent a device the interior of the tubing can be relieved by either slackening off one of the wick seals or slackening off one ofthe 'T'-piece blanking members.

The invention will now be described by way of example with reference to the accompanying drawings in which: Fig. lisa front view of part of an assembly made up of a plurality of separate independent sealed reservoirs constructed in accordance with the invention, Fig. 2 is a front view of a tractor on which an arrangement such as that shown in Fig. 1 is mounted in which extreme ends of the unit are pivotable or hingeable relative to the remainder of the unit to allow the overall width of the unit to be decreased to allow it to pass through restricted gateways and along ordinary roads, Fig. 3 is a top plan view of another embodiment of the invention in which the individual elongate reservoirs are pivotally mounted on and below a boom mounted at the front of the tractor, Fig. 4 is another top plan view of another embodiment of the invention in which two relatively displaceable booms each in the form of at least one of the unit length members according to the invention are pivotally joined at their front end to a load bearing spigot from a tractor and can be swung outwardly or inwardly as required.

Fig. 5 is an end view of another arrangement of the invention in which the tubular reservoirs are located in an angular seating and retained in position by means of clips, Fig. 6 is a similar end view of another embodiment of the invention in which the tubular reservoirs are aligned relative to orthogonal surfaces which may extend over some or all of the length of the array of tubular reservoirs and in which at least one sector plate is provided at one end of the boom so formed and preferably two such plates are provided one at each end and a bolt and wing nut is provided for retaining each set plate at a desired angle of inclination relative to an axis of pivoting.

In Fig. 1 of the drawings a wick bar applicator is shown made up of separate relatively short standard length tubular reservoirs of plastics material one of which is generally designated by reference numeral 10.

The reservoir is formed with a series of holes through which wicks extend one of which is denoted by reference numeral 12. Where the wicks pass through the wall of the reservoir 10 sealing means is provided to prevent loss of fluid from within the reservoir.

The ends of the units are squared off by means of flush cylindrical end caps of which one is shown at 14. The end caps are formed from clear plastics material such as an acetal resin, polystyrene or polyethylene.

The purpose of the end caps 14 is twofold.

1. By virtue of their transparency, the contents of the tubular reservoir can be seen and noted.

It is important to maintain the level of the fluid within the reservoir 10 so as to maintain a minimum head of liquid pressure acting on the inboard ends of the wicks.

The joins between adjoining tubular reservoirs are retained by means of cylindrical sleeves 16 and 18 which firmly clamp the tubular reservoirs together.

2. By using end caps which are squared off at their ends, so a close intimate flush abutting relationship between adjoining end faces of two reservoirs can be obtained.

Brackets may be provided which are attached to the cylindrical bands 16 and 18 for securing the completed assembly to a tractor or the like or alternatively grips or bands at 20 and 22 may be provided to retain the wick bar in position on a motor vehicle.

Further details of the mode of operation and principal of operation of the wick bar applicator shown in Fig. 1 may be obtained from United States Patent Specification 4187638 reference to which is now made.

Unlike the design of the aforementioned U.S.

Patent, the liquid is introduced into the interiors of the aligned tubular reservoirs in each case through an inlet tube 24 which like the wicks is sealed to prevent the ingress of dirt and the exit of liquid from the reservoir. The tube 24 terminates in a 'T'-piece generally designated 26 and flexible hoses 28 and 30 are attached to the limbs thereof.

Fig. 2 of the drawings shows a development of the basic design shown in Fig. 1 wherein hinges are provided between the abutting end faces of the outer most reservoirs 10 and 10' on the one hand and 10" and 10"' on the other hand. The reservoirs are denoted by reference numerals 36 and 38 respectively and allow the outboard ends of the boom to be raised to reduce the overall width of the boom for transportation and storage.

To provide automatic lifting and lowering, hydraulic rams as denoted by reference numerals 40 and 42 are provided acting between the raisable outboard arms of the assembly and fixed members such as the frame 34.

Although not shown a fluid connection to a central 'T'-piece 44 allows for the supply of liquid chemical to the reservoirs.

As is well known, if it is difficult to enter the liquid into the reservoirs, internal pressure can be relieved by relieving one of the sealing rings around one of the wick outlets or around the incoming air inlet.

An alternative approach is shown in Fig. 3 in which six short uniform length cylindrical reservoirs each provided with wicks in accordance with the invention and identified by reference numeral 50 are pivotally mounted for example at 52 on a trans versely extending boom 54 which itself is rigidly mounted on a framework generally designated 56 at the front end of a tractor generally designated 58.

The reservoirs 50 are pivotally linked together through the intermediary of an elongate strut 60 which is pivoted to each of the reservoirs and maintains with the reservoirs and the boom 54 parallelograms.

A hydraulic ram 62 serves to power the unit and allow the reservoirs to be aligned with the direction of travel or contra thereto. Intermediate positions are most likely to be favoured giving widespread coverage of the crop both in duration and extent.

Fig. 4 illustrated a further embodiment somewhat similar to that of Fig. 3 in which two slightly ionger reservoirs 62 and 64 are hinged at their front end at 66 and thereby mounted on a forwardly directed strut 68 the rear end of which is attached to a framework generally designated 70 for attachment to a tractor generally designated 72. Hydraulic rams 74 and 76 allow complete control over the angular positions of the two reservoirs 62 and 64 within the limit of the rams. In order to obtain maximum extendability, the rams are convenientlytelescopic rams and the same considerations would apply to all of the references to rams herein.

Fig. 5 illustrated one method of securing a tubular reservoir on the front of a tractor or the like vehicle.

The tubular reservoir is generally designated 80 and nestles between the upright and forwardly directed members of a right angle strut 82 having cushioning material 84 and 86 to absorb impacts and stresses and strains during use. The tube 80 is held onto the cushioning and in turn is firmly held in contact with the angular strut through the intermediary of a metal clasp such as 88 the type commonly referred to as a jubilee clip.

Details of the wicks 90 and 92 and sealing transfer devices 94 and 96 are similar to those of the aforementioned United States Patent Specification.

Fig. 6 iliustrates a further arrangement for mounting the tubular reservoirs.

The reservoir 80 can of course be twisted around its axis of rotation so as to present the wicks either more or less facing downwardly or more or less facing forwardly as required. The procedure is laborious and time consuming particularly when a large numberof separate units are mounted across the width of a tractor.

An alternative and preferred arrangement to achieve this rotational movement is shown in Fig. 6.

Opposite ends of the support which takes the general form of a box section 100 which extend across the width of the wick bar assembly and a sole plate 102 on which the underside of the tubular reservoir rests, the reservoir being denoted by reference numeral 104. The sole plate 102 and box section 100 define orthogonal surfaces and may be padded as shown in Fig. 5 if required.

The reservoirs are secured to the generally rectangular recess in any known convenient manner using jubilee ciip type devices or the like.

At opposite ends are sector plates 106 of which only one can be seen in the drawing. Each sector plate includes an arcuate groove 108 and is pivotally joined to a framework member 110 secured to a tractor or like vehicle by means of a pivoting nut and bolt connection orthe like 112.

Wing nuts 112 and bolts (not shown) serve to sec urethe sector plate 106 to the strut 110 at any desired angle within the limits prescribed by the arcuate groove 108.

The assembly can be pivoted about the offset axis 112 which gives a larger swing of the external surfaces of the reservoirs 104 than would otherwise have been the case if they were simply rotated about their own axis of symmetry.

Fig. 7 shows in detail one form of inlet device.

AT' shaped connector 114 connects to flexible hosing (not shown) and the central stem of the 'T' extends in a sealing mannerthrough a flanged boss 116 which is sealed to the wall of the reservoir 118 using an '0' ring seal or the like 120.

Typically the external surface of the stem of the 'T' 122 is externally threaded and the internal surface of the hole in the boss 116 through which the stem passes is formed with a complimentary screw thread profile to allow an adjustment of height at the lower end of the stem 112 within the reservoir.

Furtherfeeding means (not shown) is provided in the event of a screw threaded relationship to prevent the exit of liquid or the ingress of dirt.

A iocking nut 124 is provided to retain the 'T' shaped piece 114 in the desired position.

At the lower end of the hollow stem 122 is located a valve seat 126 against which a spherical buoyant member 128 in the form of a ping pong ball or the like can be urged by a rising fluid level so as to cutoff the further introduction of liquid into the reservoir.

All is held captive near to the lower end of the stem 126 by means of a wire or plastics cage 130.

The diagrammatic arrangement shown in Fig. 8 illustrates how four wick bar applicator reservoirs can be fed from a single container 132 having an air vent 134 and which is connected to the central 'T' piece 136 via a flexible hose 138. The hoses 140 and 142 serve as the main distributors to T shaped connectors such as that shown in Fig. 7 at 144,146,148 and 150.

Hydraulic rams 152 and 154 serve to raise or lower the outer most units designated by reference numerals 156 and 158 respectively.

Although not shown in detail wicks 160 are located along the lower forward region of each of the tubular reservoirs.

The means for supporting the four units in position may be straight forward angle iron strut to the rear and underside of the array, or alternatively a series of strategically placed brackets or clips.

Reverting to Fig. 1, it will be noted that there is no dead space between adjoining units 10 by providing wick exists and inlets close to each end of each tubular reservoir. Two such close proximity inlet outlets are denoted by reference numerals 162 and 164.

A wick 166 extends between the two and in the course of manufacture is initially inserted and locked in position for example in aperture 162. The other end is left free and if the unit is joined to an abutting reservoir as shown in Fig. 1 the free end of the wick 166 is inserted into the inlet outlet aperture 164 and sealed in position using a screw threaded seal or the like so as to provide a bridge between the two reservoirs and also to eliminate any dead spot on the surface of the wick bar applicator.

Claims (39)

1. A reservoir for apparatus for applying chemicals to plants, comprising a length of tubing adapted to serve as a reservoir for liquid chemical and having apertures in the wall thereof through which a plurality of wicks extend for exposure to the plants, at least one end of the said length of tubing being adapted to be fitted to a co-operating end of a similar length of tubing to form a boom having a length greater than that of the individual parts.

2. A reservoir according to claim 1, wherein the tubing is of generally circular cross section.

3. A reservoir according to claim 1 or 2, wherein the tubing is formed from plastics material.

4. A reservoir according to claim 1 or 2, wherein the tubing is closed at each end.

5. A reservoir according to claim 4, wherein the tubing is closed by means of flush fitting end caps.

6. A reservoir according to claim 5, wherein the end caps are formed from or include transparent sections to constitute windows.

7. A reservoir according to any one of the preceding claims, wherein the tubing includes one or more internal walls to divide the interior of the reservoir into short lengths.

8. A reservoir according to claim 7, wherein the internal walls seal off the short length from one another.

9. A reservoir according to gny one of the preceding claims, wherein both ends of the tubing are adapted to be fitted to a similar length of tubing.

10. A reservoir according to any one of the pre weeding claims, wherein the end or ends adapted to be fitted together are squared off.

11. A reservoir according to any one of the preceding claims, wherein the tubing includes one or more venting and filling apertures.

12. A reservoir according to claim 11, wherein the tubing includes a single venting and filling aperture provided with a one-way valve arranged to permit liquid to pass into the interior of the tubing but not in the reverse direction.

13. A reservoir according to claim 12, wherein the one-way valve is associated with a level sensitive device arranged to prevent inflow of liquid into the tubing when the liquid level within the tubing exceeds a given value.

14. A reservoir according to claim 13, wherein the valve comprises a floating ball valve in which a floating ball is held captive within a cage through which liquid and air can pass and a seating is provided against which the ball is forced upon increase of the liquid level within the tubing.

15. A reservoir according to claims 12, 13 or 14, wherein the aperture is located substantially midway between the ends of the tubing.

16. A reservoir according to any of claims 12 to 15, wherein the aperture is provided with a T-piece having a downwardly extending filler/vent tube communicating with a tubular cross-piece.

17. A reservoir for apparatus for applying chemicals to plans, substantially as herein described with reference to, and as shown in, the accompanying drawings.

18. A boom for applying chemicals to plants, comprising a plurality of reservoirs in accordance with any one of the preceding claims.

19. A boom according to claim 18, wherein the reservoirs are aligned with one another and fitted together in end to end relationship.

20. A boom according to claim 19, wherein adjacent reservoirs are held together by a cylindrical sleeve circumscribing annular end regions of the two abutting lengths of tubing.

21. A boom according to claim 19, wherein adjacent reservoirs are held together by male and female joint means.

22. A boom according to claim 19, wherein adjacent reservoirs are held together by means of a screwthrnaded joining member.

23. A boom according to any one of claims 19 to 22, wherein the or each joint between the two abutting ends of adjacent reservoirs does not extend radially beyond the cross-sectional area of the two lengths of tubing.

24. A boom according to any one of claims 19 to 23, wherein the or each join between adjoining lengths of tubing is bridged by at least one wick.

25. A boom according to claim 24, wherein the pattern of exposed wicks on the external surface of the tubing is uninterrupted at the or each join between adjacent lengths oftubing.

26. Aboom according to any one of claims 19to 25, wherein the lengths oftubing are supported at least in part by brackets located at the joints between adjacent lengths of tubing.

27. A boom according to any one of claims 19 to 25, wherein the lengths of tubing are supported at least in part by a right-angle support frame having a horizontal forwardly extending limb on which the tubing is supported and an upwardly extending limb, retaining means being provided for retaining the tubing on the frame.

28. A boom according to any one of claims 19 to 25, wherein each length of tubing is supported by one or more brackets, the brackets being carried by a support frame or arm adapted to be mounted, or mounted on a wheeled vehicle so as to extend at an angle relative to the direction of movement of the vehicle.

29. A boom according to any one of claims 19 to 28, wherein adjoining lengths of tubing are hinged relative to one another.

30. A boom according to claim 29, further comprising one or more hydraulic or pneumatic rams for adjusting the relatively hingeable lengths oftubing.

31. A boom according to claim 18, comprising a plurality of relatively short lengths of closed tubing each secured at a point substantially midway along its length to a boom support member.

32. A boom according to claim 31, wherein each length of tubing is pivotally mounted to the boom support member.

33. A boom according to claim 18, comprising two relatively pivotable lengths of closed tubing each of which is pivotally attached to a forwardly extending strut for arcuate movement about a generally vertical common axis.

34. A boom according to claim 33, further comprising means for pivoting the lengths oftubing inwardly and outwardly relative to one another.

35. A boom according to any one of claims 18 to 34, wherein each length of tubing is supported for rotation about an axis aligned with the axis of the tubing or offset therefrom.

36. A boom according to claim 35, wherein the tubing is mounted on a support having associated therewith a flange plate having an arcuate slot therein.

37. A boom according to any one of claims 18 to 36, further comprising a common feed arrangement for filling a plurality of lengths of closed tubing.

38. A boom for applying chemicals to plants, substantially as herein described with reference to, and as shown in, the accompanying drawings.

39. Apparatus for applying chemicals to plants comprising a boom made up of two or more separate lengths of reservoir tubing hingedlyjoined together and from each of which extend along the external surface thereof liquid depositing means in the form of wicks at least one of which from each said reservoir tube extends across the junction between the one tube and an adjoining tube and terminates in the adjoining tube so that a continuous run of wicks is available across the length of the aligned tubes.