Note: Descriptions are shown in the official language in which they were submitted.
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TITLE: A METHOD FOR HARVESTING A BLUEBERRY FIELD
FIELD OF THE INVENTION
This invention pertains to commercial blueberry harvesting methods, and
more precisely the present invention pertains to the handling of blueberry
containers in a blueberry harvesting operation.
BACKGROUND OF THE INVENTION
In a common commercial blueberry harvesting operation, the harvesters are
mounted to relatively large farm tractors. Generally, a platform is provided
on the back of the tractor to carry a number of empty blueberry containers
and a number of full blueberry containers. The full blueberry containers
are carried on the platform until most or all the blueberry containers are
full. The harvester is then driven to the edge of a field where the containers
are unloaded and transferred to a flat bed truck for example and carried to
a warehouse or a processing plant.
Upon unloading the full blueberry containers to a shuttle truck, the
harvester is reloaded with empty blueberry containers and harvesting is
resumed.
For reference purposes, examples of blueberry and cranberry harvesters of
the prior art are identified in the following publications:
US Patent 2,037,624 issued to H.J. Franklin on April 14, 1936;
US Patent 2,795,099 issued to L.C. Getsinger on June 11, 1957;
US Patent 3,616,630 issued to G.L. Gray et al. on November 02, 1971;
US Patent 3,648,447 issued to C.G. Burton on March 14, 1972;
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US Patent 3,724,168 issued to H.W. Cassady Jr. et al. on April 3, 1973;
US Patent 4,862,683 issued to R.D. Bragg et al. on September 5, 1989;
US Patent 5,024,052 issued to R.D. Bragg et al. on June 18, 1991;
US Patent 5,369,944 issued to 0. Robichaud on December 6, 1994;
US Patent 5,375,403 issued to G.E. Collins et al. on December 27, 1994;
US Patent 6,000,203 issued to L.H. Weatherbee et al. on Dec. 14, 1999;
US Patent 7,716,909 issued to Dario Hebert on May 18, 2010;
CA Patent 1,249,727 issued to R.D. Bragg et al. on February 7, 1989;
CA Patent 1,318,135 issued to R.D. Bragg et al. on May 25, 1993.
The blueberry picking device described in US Patent 7,716,909 issued to
Dario Hebert herein above is particularly appropriate for mounting to the
front end of a small tractor. It is appropriate for mounting to the front end
of a small tractor of the type that is used on commercial lawn mowers and
hobby farm equipment for examples. These small tractors have a capacity
between 25 and 40 hp., and a weight of about 1600-1800 lbs.
For comparison, the older blueberry harvesters such as the ones described
in US Patent 4,862,683; US Patent 5,369,944 and US Patent 6,000,203 for
examples, are mounted to larger tractors which could weight between 2500-
7,000 lbs and more. The footprint pressure of these large tractors is
relatively high as they are made to travel on gravel roads, hay fields in dry
season and forest floors. The tire threads on the large tractors are made for
traction rather than low surface pressure. The tire threads are not made to
be gentle to the plants and root systems on which they travel. The V-shape
threads of a farm tractor wheel for example, has aggressive thread edges
that can shear the root system of blueberry plants, just from the weight of
the tractor itself. It is believed that such breakage of the root systems of
blueberry plants can adversely affect crop during the next season.
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Although blueberry plants need pruning, it is believed that damage to the
deep root systems and to the creeping stems (rhizome or surface roots) of
blueberry plants should be avoided to maintain good plant production.
The operation of the large blueberry harvester requires a constant forward
motion by the tractor. When one of the wheel encounters an obstruction,
such as a bolder, more power is applied to the wheels from the engine's
governor, so that the tractor can roll over that obstruction without
faltering.
Every time a large torque is applied to the wheel, the sharp V-threads of the
wheels are susceptible of damaging the root systems and the surface stems
(rhizomes) of some blueberry plants.
The Hebert blueberry picking head (US Patent 7,716,909) has opened an
opportunity for harvesting blueberries using lighter machines. Moreover,
the Hebert picking head is operated in a repetitive back and forth
movement where excessive wheel torque on the tractor is never required.
If an obstruction is encountered, the natural back-and-forth rocking motion
of the machine can overcome it.
Also, the smaller and lighter tractors used to operate the Hebert picking
head reduce soil compaction and create less plant damage in a blueberry
field. The smaller lawn-type tractors mentioned above have a low footprint
pressure, for being designed to operate on lawns and gardens that are
watered and aerated on a regular basis. The tires on these tractors are
relatively wider and the thread pads are large and closely spaced. Plant
damage is reduced by both the tires profile and a lighter tire work due to the
nature of the Hebert harvesting head.
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The Hebert picking head has created an opportunity for a method for
harvesting a blueberry field, without applying damaging pressure to the
root systems of blueberry plants.
However, these smaller machines cannot carry as many blueberry
containers as the larger tractors. This reduction in carrying capacity can
represent an impediment to productivity if harvesting must be interrupted
to transport each full berry container to an access road at the edge of a
blueberry field.
Therefore, it is believed that there is a need in the blueberry farming
industry for a new method for handling berry containers with the smaller
machines such that the productivity of a picking head on a small tractor is
comparable to the work of the larger harvesters on large farm tractors.
SUMMARY OF THE INVENTION
In the present invention, there is provided a method for harvesting
blueberries with a small tractor wherein the productivity is comparable to
the larger harvesters. In the new method, the harvester carries a number
of empty blueberry containers and each blueberry container is deposited on
the ground in a specific way as soon as it is full. Harvesting continues in
one of the empty containers. Because of this method the ground pressure
of the harvester is always kept relatively low.
In a first aspect of the present invention, there is provided a method for
harvesting a blueberry field comprising the steps of: carrying a number of
empty blueberry containers on a four-arm lift of a blueberry harvester.
Empty blueberry containers are transferred, one at the time to the right side
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of the four-arm lift, under the end of a longitudinal conveyor. The first
empty blueberry container under the longitudinal conveyor is filled with
blueberries. This first blueberry container is deposited to the ground as
soon as it is full. The above steps of transferring, filling and depositing
are
repeated until all the empty blueberry containers are full.
In another aspect of the present invention, there is provided a method for
harvesting a blueberry field, comprising the steps of: carrying a first and
second blueberry containers on respective arm-pair of a four-arm lift
mounted to the rear end of a blueberry harvester. The first blueberry
container is filled with blueberries. The first and second blueberry
containers are deposited side-by-side on the ground using the four-arm lift,
as soon as the first blueberry container is full of blueberries. The present
method also includes the steps of manoeuvring the blueberry harvester
forward and backward and selectively picking up the second blueberry
container with the right side of the four-arm lift; raising the second
blueberry container under the longitudinal conveyor, leaving the first
blueberry container on the ground, and filling the second blueberry
container with blueberries.
In yet another aspect of the present invention, the method of harvesting a
blueberry field as described above includes the step of moving backward
and away from a harvesting stop line, depositing the full blueberry
container and one empty container side-by-side on the ground, picking up
the empty container and raising it under the longitudinal conveyor and
moving forward to the last harvesting stop line. The step of depositing is
effected at a distance from an unharvested area of the blueberry field that
is farther away from the last harvested strip than the width of the harvester.
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The space left between the full blueberry container deposited on the ground
and the last harvested strip in the blueberry field provides space for the
harvester to reposition itself to pick up the empty container without running
over any unharvested area of the blueberry field. Furthermore, the
depositing of a full container and the picking up of an empty container
under the longitudinal conveyor is effected without turning the harvester
around. The steps of depositing and picking up are done with minimal
steering in the field.
Because of the low footprint pressure of the smaller tractor; the lighter tire
work associated with the Hebert picking head; the load limitation of only
one full container, and the minimum steering during manoeuvring the
harvester to deposit a full container and to pick up an empty one, there is
less damage done to the root systems of blueberry plants in a blueberry
field. Production of blueberry plants can only be improved.
This brief summary has been provided so that the nature of the invention
may be understood quickly. A more complete understanding of the
invention can be obtained by reference to the following detailed description
of the preferred embodiment thereof in connection with the attached
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the method according to the present invention
is described with the aid of the accompanying drawings, in which like
numerals denote like parts throughout the several views, and in which:
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FIG. 1 is a perspective rear view of the small blueberry harvester used in
the present method for harvesting a blueberry field and for handling
blueberry containers when harvesting a blueberry field;
FIG. 2 is a rear view of the small blueberry harvester with blueberry
containers loaded thereon;
FIG. 3 is a plan view of the small blueberry harvester with containers
loaded thereon;
FIGS. 4 - 7 illustrate four plan views of the small blueberry harvester
representing four different steps in the present method for harvesting a
blueberry field and for handling blueberry containers in a blueberry field.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1, 2 and 3, the preferred blueberry harvester 20 will be
described. The tractor used in the preferred blueberry harvester 20 is a
relatively small tractor 22 of the type that is used on commercial lawn
mowers for example. Examples of such smaller tractors suitable for the
present application are Kubota tractors, models F3680 and F3990.
The footprint pressure of these tractors is designed to be less that the
strength of a sod layer that has been watered, fertilized and aerated
regularly. Even with the added load of a lawn mower deck or a small
backhoe, the footprint pressure is less that the strength of a common lawn
surface. The tires on these tractors are relatively wide and the thread
surfaces are relatively smooth.
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A preferred blueberry picking head for mounting on the preferred harvester
20 is the comb-type Hebert picking head 24 as described in US Patent #
7,716,909. A transverse conveyor 26 is mounted between the tractor 22
and the picking head 24. The transverse conveyor 26 has a discharge end
over the front end of a longitudinal conveyor 28. The longitudinal
conveyor 28 extends to the side of the tractor 22 and ends up over a berry
receiving container 30, supported on a pair of lower arms on the rear end
of the tractor 22.
As mentioned above, the rear end of the tractor 22 has a four-arm fork lift
assembly mounted thereon. The fork lift assembly has four arms forming
two pairs of lower arms 32, 34 that are mounted side-by-side to a common
raisable frame 36. The lower arms 32, 34 extend horizontally backward
relative to the tractor 22 and are movable in unison.
The common raisable frame 36 and the lower arms 32, 34 are movable up
and down in a fixed vertical telescopic slide 38. The fixed vertical slide
38 is attached to the tractor 22. The movement of the lower arms 32, 34
and of the common raisable frame 36 relative to the fixed vertical slide 38
is effected by one or more hydraulic cylinders 40 as shown in FIG. 3. The
lower arms 32, 34 are movable vertically from the ground surface to a
distance equivalent to about the height of a blueberry container 30.
The fixed vertical telescopic slide 38 has a crossbar 42 mounted thereto.
A pair of upper arms 44 extends horizontally backward from the crossbar
42 substantially above the pair of lower arms 34. The upper arms 44 are
fixed relative to the lower arms 34. The upper arms 44 remain at a same
height when the lower arms 32, 34 move up or down.
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Each upper arm 44 has a pair of movable flaps 46 mounted and articulated
thereto. The flaps 46 are operable by hydraulic cylinders 48, from a
vertical position as shown in FIG. 1, to a horizontal position as illustrated
in FIGS. 2 and 3. As it will be understood from the illustration in FIG. 2,
the flaps 46 are operable to retain a stack of empty blueberry containers 50
above the lower arms 34, and to selectively release one empty container 50
at the time onto the pair of lower arms 34 under the stack of containers.
In use, the empty berry containers 50 are stacked by hand on the upper arms
44 with the flaps 46 in a horizontal locking position.
In a harvesting operation, the berries picked up by the picking head 24 are
dumped into the transverse conveyor 26. The berries are moved along the
transverse conveyor 26 and into the longitudinal conveyor 28. The
longitudinal conveyor 28 discharges the berries into the receiving container
30 resting on the right side forks 32 of the four-arm lift assembly of the
harvester 22. This operation can be better understood when referring to
FIG. 3.
While blueberries are being collected into the receiving container 30 resting
on the right side lower arms 32 of the harvester 20, the stack of empty berry
containers 50 is carried on the left side lower arms 34, and on the upper
arms 44 above the left side lower arms 34.
The receiving container 30 is raised on the lower arms 32 until a forward
segment of its rim is caught as a cantilever under a retaining flap 52. This
flap is affixed to the crossbar 42 as can be seen in FIGS. 1, 2 and 3.
In normal crops, a stack of four (4) empty containers 50 with one (1)
receiving container 30 provide sufficient space for collecting berries across
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blueberry fields classified as medium size to large fields. During each
"run", the harvester 20 carries the load of the empty containers 50 plus the
load of the partially full receiving container 30. When the receiving
container 30 is full, it is released to the ground as it will be explained
later.
Therefore, the harvester 20 is never loaded in excess of one full berry
container 30 plus four empty ones 50.
The blueberry containers 30, 50 that are mentioned and illustrated herein
have a capacity of about 12-14 cu ft. A container of that size full of
berries can weigh in excess of five hundred pounds (500 lbs). Therefore,
a full berry container 30 is deposited to the ground as soon as it is full in
order to maintain a safe tractor footprint pressure.
A safe footprint pressure of a tractor used in the harvesting of blueberries,
is defined as the pressure that is less than the support strength of the
surface
bushes and root systems of the blueberry plants in a blueberry field.
In the method according to the preferred embodiment, any excessive soil
loading pressure is prevented by discharging the receiving blueberry
container 30 as soon as it is full. Relatively speaking, the weight of the
empty containers 50 are negligible for corresponding to the weight of a
lawn mower deck, a garden tiller or a similar tractor accessory. The weight
of such tractor accessory is included in the design of the tires of the
preferred tractor 22 such that the footprint pressure of the tractor with
accessory is a safe one for soft lawn surfaces.
Referring now to FIGS. 4-7, the preferred method of handling berry
containers will be described. In FIG. 4, the preferred small harvester 20
is illustrated working a blueberry field 60 one strip 62 at the time. The
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movement of the harvester 20 can be understood as moving in a counter
clockwise direction relative to the blueberry field 60, where the
crosshatched area 64 represents an unharvested area, and the unmarked
area 66 represents a harvested area.
When the receiving container 30 is full of blueberries, the harvester 20
backs away from its last harvesting stop line 68 in the blueberry field 60,
in the direction of arrow 70 in FIG. 4. During the backing up along the
arrow 70, the harvester 20 moves away from the last harvester strip 62 a
distance of about at least one full width of the harvester 20 into the
harvested area 66 of the blueberry field. This way, the full blueberry
container 30 is deposited to the ground in a location that will not hinder the
harvesting of a subsequent strip 62 in the unharvested area 64 of the
blueberry field.
Referring now to FIG. 5, the harvester 20 having backed up along the
arrow 70, the harvester operator lowers the lower arms 32, 34 to the
ground, and moves the harvester 20 in a forward direction along arrow 72,
as illustrated in FIG. 5. The result of this movement is that both the full
berry container 30 and the lowermost empty container 50 are deposited
side-by-side on the ground.
The harvester 20 can now be moved backward again in the direction of
arrow 74 in FIG. 6. During this backward movement, the harvester 20 is
also moved sideways a half-width of the harvester toward the last harvested
strip 62. During this backward movement, the lowermost empty berry
container 50' that was left on the ground is picked up over the right side
lower arms 32, and raised under the conveyor 28. That berry container 50'
becomes the next receiving container 30.
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Having a receiving container 30 on the right side lower arms 32, the
harvester 20 can now be repositioned along the strip 62, along arrow 76 in
FIG. 7, and resumes harvesting from its last position 68, without having
driven over any unharvested area. Also, the harvester 20 is moved from its
last harvesting stop line 68 and back to its last harvesting stop line 68
without having to turn about and gouge the soil with hard steering as it is
the case with large harvesters during their turning around in a blueberry
field.
The full receiving blueberry container 30 is left on the field for pick up by
a dedicated fork lift tractor. This fork lift tractor (not shown) picks the
full
blueberry containers 30 and carry them to a flat bed truck or a trailer for
example at the edge of the field. The fork lift tractor (not shown) is
preferably a front end loader tractor for example. Again, the footprint
loading of that fork lift tractor is also minimal for carrying only one full
container at the time.
In summary, the method for harvesting a blueberry field according to the
preferred embodiment of the present invention is described as follows:
- providing a small and light-weight harvester 20 with a comb-type
blueberry picking head 24;
- loading a receiving container 30 on a first pair 32 of lower arms of a four-
arm lift assembly on the harvester 20;
- loading several empty containers 50 on a second pair 34 of lower arms on
the four-arms lift assembly;
- harvesting a blueberry field in a counterclockwise direction from the
outside in, defining a harvested area 66 outside the field and a
unharvested area 64 in the central area of the field;
- harvesting blueberries and filling the receiving container 30 with
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blueberries;
- moving the harvester 20 backward from a harvesting stop line 68 and
sideways to the right, away from a last harvested strip 62;
- lowering and depositing the receiving container 30 and one empty
container 50 on the ground side-by-side in the harvested area 66;
- manoeuvring the blueberry harvester 20 forward, leaving the empty
container 50' and the full receiving container 30 on the ground;
- manoeuvring the harvester 20 backward and sideways with the first and
second pairs of lower arms 32, 34 in a lower position, and picking
up the empty container 50' on the first pair of lower arms 32;
- moving the blueberry harvester 20 forward and sideways to the left to the
last harvesting stop line 68, leaving the full container 30 on the
ground;
- resuming harvesting of blueberries and filling the empty container 50' on
the first pair of lower arms 32 with blueberries; and
- repeating the steps of depositing the receiving container 30 on the ground,
manoeuvring and picking an empty containers 50', until all the
empty containers 50 on the second pairs of arms have been filled
with blueberries.
The transfer of an empty container 50' under the longitudinal conveyor 28
can be effected in about one minute or so. The harvester 20 has minimum
downtime so that productivity of the smaller harvester 20 is as high as other
more conventional harvesters. The harvester 20 maintains a foot print
loading that is very small as compared to the harvesters of the prior art.
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