Note: Descriptions are shown in the official language in which they were submitted.
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METHOD AND APPARATJS FOR CROP SPRAYING
This invention relates to a method and apparatus for
crop spraying. In the growing of agricultural and
horticultural crops, treatment of same by spraying, for
example to protect the crop against pests and diseases, is
now an important part of the crop growing programme.
However, conventional field spraying equipment is
subject to significant shortcomings due to the fact that
the spray only reaches the portion of the foliage directly
in the path of the spray. Thus, where a crop has dense
foliage, as in the case of a potato crop, the applied spray
does not reach the lower leaves beneath the top leaf cover.
As potato crops are highly susceptible to fungal attack,
this inability to properly spray the crop is of
considerable significance.
There is disclosed in US 1,348,038 (Neumeyer) a sprayer
for plants in which spaced downwardly extending pipes 16 are
fixed to a transverse pipe 14 and deliver liquid to nozzles
which are usually directed upwardly to deliver spray onto
vines from below and upwardly. There is a similar disclosure
in CH 229,146 (Leuenberger). Both these prior specifications
show the use of fixed droplegs or the like for spraying
between crop rows in a generally upwardly-directed direction,
and are subject to the shortcoming that, in use, the droplegs
vary in their proximity to the crop rows and in the case of
established crops may cause significant damage.
In FR 2 563,970 (Balligand) there is disclosed a
shredding/spraying implement in which individual units are
biased laterally outwards in one particular direction against
the crop rows in order to follow their irregular profile by
actual contact with the crop stalks. Such a proposal is
unacceptable for a machine intended to minimise crop contact
and damage.
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An object of the present invention is to provide a
method and apparatus for spraying offering improvements in
relation to one or more of the matters discussed herein, or
generally.
According to the invention there is provided a method
and apparatus for spraying as claimed in the accompanying
claims.
In a preferred embodiment, a spraying device is
provided which provides full spray cover for the crop being
sprayed. A spray boom of the apparatus is more rigid than
previously proposed booms. Attached to the boom are a
number of support elements or drop legs di sposed so as to
correspond to, for example, the ridges which a potato crop
is grown on. The support elements are trailed from the
spraying boom. Each support element takes the form of a
hinged or arm which is attached to the boom at one end and
is allowed to rest on the bottom of the valley between the
potato ridges. The support elements serve to mount
spraying devices which, in use, coat the under-side of the
potato crop. Each support element may have a separator
which allows the support element to pass through the potato
foliage without causing damage. The trailing support
element, or arm, is in contact with the uneven surface of
the soil. This causes vibration of the support element.
The vibration assists the leaf separator in its row-opening
function. In the preferred embodiment, spraying can be
effected even in windy conditions, as the micro-environment
provided by the potato leaf cover reduces the wind drifting
effect on the spray. In the event of too much movement of
the support elements being caused in use, a damping device
may be provided. Each support element may have more than
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one spray jet to produce greater spray cover.
The boom supporting the support elements may be
arranged to fold, with the support elements thereon, to
enable a relatively narrow transport width of the apparatus
to be provided for use on public highways. The apparatus
may well be usable in applications other than in relation
to potato crops.
~n the e;nbodiments, :~~eans is included ..o assist the
centralising of the support elements ;~~ith r°spect
to the crop rows. This arises from difficulties
in forming potato ridges with exactly correctly positioned
row centres. Considerable variations can occur in
this respect, depending on tractor driver ability,
prevailing soil condi~ions, and fi°ld gradients.
To meet the problems caused by ~~andering of the crop
ro~~~s in a lateral direction, the embodiments have
free floating self-aligning support elements, or arms,
which centre-themselves with respect to the bottom
of the valley between successive potato ridges. In
one embodiment instead of the support elements being
pivotally mounted directly on tha boom, they are mounted
on a carriag a which can move laterally with respect to the
boom to prod uce the self-alignment function. The boom has
one or more rails on which the carriage is mounted for
rolling movement. The support elements and the carriages
may be interconnected so that the support elements achieve
lateral movement in unison or with a variable degree of
independence.
In a further preferred embodiment, attention is given
to the problems of providing a sufficiently narrow
transport width for the apparatus, having regard to the
need to transport the apparatus to and from its place of
work, via public highways. There is also'a need for the
folding of the boom to be able to be effected by the
tractor driver form his in-cab working position, without
descending from the cab.
In this preferred embodiment, the boom has a generally
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triangular cross-sectional shape to provide additional
stiffness. Previously proposed boom constructions would
have inadequate stiffness and would twist in use.
A further factor in relation to this aspect of the
invention concerns the need to avoid interaction of the
support elements, or arms, in the transport position of the
apparatus. In this preferred embodiment, a boom span of 12
metres can be folded within the raar profile of a tractor.
Moreover, the support elements, attached to the lower side
of the generally triangular cross-sectional shape do not
interlock, as between those on one section of the boom, and
those on a neighbouring section. The support elements ar_:~
freely suspended from the boom and fold flat against it
when it is raised for transport. The boom is formed with
multiple sections which can be readily folded. The nearest
section of the boom to the sub-frame which mounts on the
hitch links of the agricultural tractor, is hinged so that
when it is in its transport position, it lies over the rear
of the sub-frame, along with the other attached sections.
All sections can be folded independently of one another,
enabling differing boom widths to be achieved.
Construction of the boom and sub-frame may be of steel or
aluminium or suitable alloy, and may be formed as a space
frame or monocoque construction. A section through the
boom may be triangular, or it may be found convenient to
construct a section with more or less faces which are
straight or curved. Safety break-away hinging may be
provided either in each section of the boom, or in the sub-
frame. The boom may also be provided with spray jets of
the kind for spraying downwards from the boom, for use on
land, or in the air.
The boom may be provided with an air collector to
deflect the air flow that occurs when the booms are being
passed over a crop, to deflect air flow generally
downwardly towards the crop. This assits in retaining the
fine spray droplets within the foliage cover, so as to
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inhibit drift to other crops or neighbouring fields.
In a still further preferred embodiment, attention is
given to the need to centralise the support elements, or
arms, with respect to the rows, and to the need to provide
sufficient response to crop density, and to avoid crop
damage. An additional factor considered is problems
arising from boom tilt on uneven ground. Such tilt leads
to the distance between the tip of the support elements, or
arms, and the soil surface varying to an extent which
affects the performance of the spray means on the support
arms. Also, there is a need to provide improved means for
Folding the support arms for transport.
In this preferred embodiment, a universal coupling has
been provided between the support arms and the carriages
which permit them to move laterally with rspect to t':~e
boom. By the use of springs and adjustment chains, a
multi-directional device is provided which can be adjusted
to suit prevailing conditions. This feature also assists
when folding the.apparatus for transport, adjusting for
crop density, and has added extra performance in allowing
the support elements to move away from o'pstacles on the "
ground, or constituted by lodged crops. The support
elements are thus able to weave in a lateral direction
without affecting the spray performance, and damage to
crops is reduced. In this embodiment, control of boom
height and tilt has been achieved by praviding sensors on
the boom which are in contact with the soil surface. The
sensors switch electrically operated actuators to level the
boom so that the drop legs are positioned correctly in
relation to the soil surface. A general height control
facility is also incorporated in the system and is operated
by utilising a parallel linkage between the sprayer main
chassis and the boom. The linkage is actuated by an
electrically driven actuator which can be controlled by
either manual or automatic sensing. Provision is also made
for the height control to be integrated with the tilt
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control thus making the adj ustment of the boom automatic
when spraying, thereby leaving the driver free to control
the tractor.
In another preferred embodiment, a modification to the
support elements, or arms, is provided. This is proposed
for use in extreme cases where a crop has become completely
lodged, or tangled. The support element is replaced by a
rimless spoked wheel. The wheel has a convenient number of
radial spokes which have a supply of sprayed liquid fed to
them from the hub of the wheel. The fluid is distributed
by a valve system to each of the spokes. At the ends of
the spokes are attached a number of spray jets which are
angled to spray the crop from the side. In order to avoid
all the jets working all of the time, a hub valve system is
provided so as to shut off the liquid when the spokes are
out of the crop. In order that the spokes do not entangle
the crop they are made adjustable so that the correct crop
engagement angle may be achieved. This wheel spraying
system and the support element or drop leg'system are
interchangeable.
Embodiments of the invention will no w be described by
way of example with reference to the accompanying drawings
in which .
Fig 1 shows a plan view of a tractor and sprayer,
sho wing the support elements or spraying arms extending
rearwardly from the boom of the sprayer;
Fig 2 shows, diagrammatically, a support element, or
spraying arm, in action, the view being from above;
Fig 3 shows a side elevation view of a support element
or spraying arm;
Fig 4 shows a plan view of the support element or
spraying arm of Fig 3;
Figs 5 and & show a second embodiment, Fig 5 showing a
plan view and Fig 6 an elevation view of a carriage
assembly for mounting a modified support element or spray
arm on the boom;
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rFig 7 shows, diagrammatically, the manner of folding
the boom, this figure showing the boom in its half-folded
position and attached to the tractor sprayer frame;
Fig 8 shows the boom unit folded behind the rear of
the tractor;
Fig 9 shows a side elevation view of a modified
spraying assembly in which a rotary wheel having radial
sproke type spraying arms is employed to enter lodged crop;
Fig 10 shows a plan view of the assembly of rFig 9;
Fig 11 shows a modification of the embodiment of rF ig
3;
Fig 12 shows a plan view of the support element
assembly of Fig 11;
rF ig 13 shows a plan view, similar to that of r~ig 5,
showing a folding end portion of the boom, one exemplary
carriage mounted thereon, and an actuatable finger
mechanism for limiting lateral carriage movement when the
boom f old s ; .,
Fig 14 shows an end elevation view of the boom,
similar to that of Fig 6, with the support elements
omitted, and the boom shown in a folded configuration;
Fig 15 shows a rear elevation view of a folding end
portion of the boom, shown partially folded; and
Fig 16 shows an end elevation view of the boom,
similar to that of Fig 14, and showing a support element
location within an associated air duct.
As shown in Figs l and 2, a tractor 10 is drawing
spraying apparatus 12 to spray a potato crop 14 in which
there are valleys 16 between successive ridges in the
earthed-up crop. The tractor runs with its wheels 18 in
these valleys.
The spraying apparatus 12 comprises booms 20 extending
laterally over the crop rows. The booms having trailing
support elements 22 which extend downwards between the
crop rows to the bottom of the valleys 16 so as to effect a
spraying action as indicated at 24 in Fig 1.
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ids shown in Fig 2, a fowardly extending separator
element 26 is provided in front of each of the support
elements or arm s 22 to divide a path through the leaves 23
of the potato crop, thereby enabling the trailing arm 22 to
pass through the foliage without causing damage. The spray
nozzle 30 which produces the spray 24 is positioned in the
correct location on arm 22, to spray the undersides of the
foliage 18 by means of a horizontally and/or verticall;r
directed spray pattern as indicated at 24.
In Figs 1 and 2, the lines of the crop rows themselves
(ie effectively the tops of the potato ridges, below which
the potatoes the mselves have been planted), are indicated
by reference numeral 32, whereas the valleys between the
ridges and a long which the row units of the sprayer pass
(ie the support elements 22), together with the tractor
wheels, are indicated at 16, as already mentioned.
Figs 3 and 4 show further details of the row units 34,
for each of the crop rows, each row unit comprising a
support element or arm 22. rFOr each ro w unit, there is
provided below boom 20 a bracket 36. The support element
or arm 22 is pivotally connected to the bracket. The leaf
divider 26 is attached to arm 22. The pivot connection 38
on bracket 36 to arm 22 provides a degree of lost motion
or float whereby the arm 22 is able to move laterally, to a
certain extent, to accommodate lateral wondering of the
crop rows.
A shock absorbing device 40 is provided at the
trailing end of each arm 22 for engagement with the ground
and comprises a spring 42 and a pivoted slider member 44.
A flexible spray feed pipe 46 delivers spray liquid to the
nozzle 30 and accommodates movement of the arm 22. Tube 46
is fed from a manifold 48.
In use, the support elements 22 extend downwardly
between the crop roans 32 as the apparatus travels in
direction F lengthwise of the rows. The nozzles 30 spray
liquid upwardly and/or horizontally with respect to the
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9
ground so as to treat the crop material in the rows. The
pivot 38 permits lateral movement of the support elements
22 with respect to their mounting to follow lateral row
contours.
In the embodiment of Figs 5 and 6 there is provided
refined and improved means for permitting lateral floating
movement of the support elements or arms 22 with respect to
their mountings and the boom, to follow lateral row
contours.
In this embodiment, the boom 50 is shown having a
generally triangular profile as seen in length:aise cross-
section. This provides the boom witz the necessary
stiffness and r?sistence to twisting Fords.
In this embodiment, the support elements have a
modified shape and profile and are indentified by ref~renc~
numeral 52, with their nozzles 54 located in the region of
their rear ends. Each support element has a downwardly and
slightly forwardly extending portion 56 leading to a
horizontal rearwardly extending portion 58. Portion 56 is
connected to a carriage 60 having wheels 62, 64 and 66
engaging rails 68, 70 carried by the boom 50. The wheels
roll on the rails with low friction, the rail and wheel
profiles avoiding a pinching action.
Carriage 60 comprises a frame 72 on which a mounting
arm 74 for wheel 66 is pivotally mounted at 76, and is
oiased by a spring 78 acting between the frame and the arm
to hold all three carriage wheels 62, 64 and 66 in
engagement with their rails. Frame 72 also serves to
provide a mounting for the support element 52.
Thus, carriage 60 is freely laterally shiftable in
both directions along rails 68, 70 to accommodate crop row
contours. The apparatus othercaise functions as in the
embodiment of rF igs 1 to 4.
An aerofoilshaped air deflector 79 on boom 50
intercepts the air flow A due to travel in direction F and
produces a downwardly directed flow D. A trailed flexible
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pvc canopy 81 serves to further confine the spray. rr~ig 6
also snows at 33 a spray bar mounted on boom 50 and
producing a downw ardly directed spray 85 for simultaneous
or sequential use with nozzles 54.
Turning now to the embodiment of gigs 7 and 8, fig 7
shows the boom 80 in a semi-folded state. A sub-frame 82
provides a mou:~ting for boom 80 on the hitch links of the
tractor (not s;~own). A corresponding boom is mounted on
the other side of sub-frame 82. This latter is not
illustrated, for reasons of simplicity of illustration.
Boom 80 is pivotally connected to sub-frame 82 at
locations 84, 86. The disposition of the axes of the
pivots is such that these are co-axial and inclined at the
angle 88 wi th respec t to sub-fr ame 82, so as to incl ine the
boom towards the back of the tractor when folded.
Boom 80 comprises boom portions 90, 92 and 94. The
boom portions are pivotally interconnected by hinge
assemblies having axes generally parallel to and close to
the triangular edge profiles of the boom portions at 9o and
98, the hinge axes being identified by reference numerals
100 and 102.
As in the preceding embodiment, the support elements
for the spraying ro w units are mounted on rails 104, 106.
These rails are shown, in Fig 7, for each of the boom
portions, and thus the location of the spraying devices in
the semi-folded condition of the boom can 'oe judged.
Fig 8 shows the boom sections 90, 92 and 94 in fully
folded transport configuration. It can be seen that the
boom assembly is located well within the lateral confines
of the tractor wheels 110.
It will be noted that in this embodiment the boom
portions are pivotal about axes which are not mutually
parallel. These axes are however parallel to or
approximately parallel to the sides of the triangular
section boom structure, whereby the compact boom folded
configuration is achieved. It will also be noted that the
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axis 112 about which the inner end of boom portion 90
pivots, leans rearwardly as it extends upwards with respect
to forward travel direction F.
Turning now to the embodiment of Figs 9 and 10, the
boom 120 has mounted thereon carriages 122. Downwardly
depending from each carriage is a support element 124,
which is biased downwardly by a spring 126. In place of
the nozzle or nozzles on each support element 124 there is
provided a rotary wheel element 128. The wheel element has
outwardly projecting spoke elements 130, each spoke element
having spray means, to penetrate lodged crop 132, in a
generally endwise manner. Liquid to be sprayed is
delivered by a flexible conduit 134 to the hub 130 of
wheel 128. The hub comprises valve means arranged to
deliver the liquid only to those spoke elements 130 which
have penetrated the crop 132, at any given instance.
As shown in Fig 9, the spoke elements 130 which are in
the crop deliver a spray of the liquid in a generally
horizontal and/or upwardly directed attitude so as to
effect treatment of the crop, as in previous embodiments.
The spoke elements deliver the spray from lengthwise-spaced
outlets or nozzles provided on the spoke elements as
indicated at 138.
In use, .the spoke elements 130 penetrate the crop and,
as the apparatus proceeds forwards in direction F, each of
the wheels 128 is generally aligned with the valley 140
between two successive crop rows 142, and the spokes 130
are driven by the crop 132 and/or light engagement with the
ground.
This embodiment is particularly well adapted to cope
with dense and lodged crop which would otherwise represent
(so far as prior art proposals are concerned) an
im possible task so far as spraying the underside of the
crop leaves is concerned, at a rate which would in any way
compare with the rate of area co~~.erage by conventional
spraying machines which spray the crop from above (and thus
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leave the underside of the leaves untreated).
Turning now to the embodiment of rr~igs 11 and 12, it
will be seen that this is a modification of the embodiment
of Figs 5 and 6. Accordingly, parts corresponding to those
of rFigs 5 and o are given corresponding reference numerals
increased by 100. Thus, rail 68 in Figs 5 and 6 becomes
168, and so on. In Figs 11 and 12, the boom 50 of Figs 5
and 6 has not been shown, for simplicity of illustration.
In this embodiment, the carriage structure 160 differs
significantly from that of the embodiment of Fig 5 and 6,
and likewise the mounting and arrangement of the support
element or arm 152.
So far as the carriage is concerned, it comprises two
pairs of wheels 162, 164 and 166, 166A journalled on
respective supports 172, 174, and held in engagement with
the rails by a telescopic plunger tube 176 having an
internal compression spring 178.
The row unit arm or support element 152 (which
supports the jet or nozzle 154) is mounted on carriage 160
by do wnwardly-depending arms 180 to which the support
element is journalled at 182. Arms 180 can turn about the
axes 183 of plunger tube 176. Element 152 is located
against rearwardly directed dynamic forces arising during
use by two coiled tension springs 184 and associated
adjustment chains 186. The spring and chain assemblies
have a line of action inclined with respect to the forward
travel direction F, thereby having a centralising effect on
the support element, while permitting lateral swinging of
the support element under dynamic forces arising during
use. Carriage 160 can, as in the previous embodiment, move
bodily with respect to the boom to accommodate row
contours. Chains 186 provide for adjustment of the norm al
working position of the support element as shown in Fig 11.
This gill depend upon the crop density, and other working
conditions. The springs provide safety overload
characteristics.
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Thus the support elements or drop legs 152 are
completely floatingly mounted to follow row contours and
respond to crop. effects in a dynamic fashion during use.
Moreover the elements 152 fold flat below the boom when
the latter is raised for transport. This is permitted by
pivotal movement about axes 183.
Laterally projecting inclined ro w guide probes or
plates 188 are provided at each side of support element
152. These are position-adjustable for contact wit': the
crop or crop ridges to exert a centralising effect on the
row unit.
In operation, this embodiment has improved dynamic
characteristics in terms of self-centralising action as the
ro w units move lengthwise or the crop rows. adjustment of
the attitude of the support elements is provided and an
adjuster 190 permits height adjustment of each support
element itself with respect to its mounting.
In the embodiment of Figs 13, 14 and 15, a folding
boom portion 200 comprises a generally triangular end frame
202 with longitudinal ties 204 and inclined ties 206,
together with spaced rails 208, 210 on which carriage 212
is freely rollingly mounted.
In Fig 13, only one carriage 212 is shown, but it is
to be understood that one such carriage is provided for
each row unit or support element of the apparatus.
In order to prevent lateral rolling movement of the
carriages to one end of the boom, when the latter is raised
for transport, means 214 is provided to limit or prevent
such movement of the carriages and their associated sup;,oort
elements in the form of a bar 216 extending lengthwise of
the boom, and having spaced finger elements 218 mounted
thereon at intervals along its length to limit lateral
movement of the carriages 212.
Bar 216 has an end portion 220 for actuating purposes,
which cooperates with a fixed actuator means 222 having a
projecting actuator element 224, and mounted on the
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adjacent non-folding boom portion, not shown in Figs 13 and
15.
Bar 216 is mounted on bearings (not shown) for angular
movement about its lengthwise-extending axis so that the
finger elements 218 move between the two positions
indicated in rF ig 14, namely a generally vertical position
in which carriage movement is limited to movement between
two adjacent finger elements, and an inclined position in
which the carriages can freely laterally float. Spring
means, for example a coiled tension spring (not shown)
biases the bar and the finger elements to the carriage-
movement-limiting position.
In use, when the boom portion 200 is in its working
position, in line with the adjacent boom portion,
engagement of actuator element 224 with end portion 220 of
bar 216 holds the finger elements 213 in their inclined
position in which lateral carriage movement is permitted.
When the boom portion is raised for transport purposes, the
relative movement between the adjacent boom portions, as
illustrated in Fig 15, causes disengagement of the actuator
element 224 from bar end por tion 220 and the spr ing means
causes the bar automatically to adopt its carriage-
movement-limiting position.
In Fig 14 there is indicated an adjacent boom portion
226 in an over-folded configuration and relationship with
respect to boom portion 200, hinge means 228 being
indicated, which permits such folding movement.
In the embodiment of Fig 16, the general arrangement
is as described above in relation to Fig 11, with the
following modifications. Parts corresponding to those
described above and illustrated in Fig 11 are given the
same reference numerals as in that figure.
In this embodiment, means is provided to assist
dispersal of spray from the swivel nozzles 154 at the rear
end of the support element 152, by providing a flow of air
indicated by arrows 230 so as to cause extra penetration,
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laterally and from below, of the adjacent crop foliage.
The air stream 230 is provided by a compressor fan
delivering through a manifold 232 having individual row
ducts 234 leading, for each row, to a boot duct 236 having
a suitably sized and profiled nozzle 238 at its lower end
for producing the air stream 230.
Boot duct 236 houses support 152 also, and the liquid
supply conduit 240 therefor which is connected to its
associated manifold 242 which can also deliver to
downwardly directed nozzles 244, for conventional spraying
purposes.
In use, the air stream from nozzle 238 greatly assists
dispersal and penetration of the crop by the spray from
swivel nozzles 154.
