The present invention relates to an automatic distributor
for transplanting machines.
Transplanting machines, as known in the art, are used for
quick transplanting of plants, vegetables, etc... grown in small cubic clods. Said
plants, while they are still rooted in the clods, are transplanted one by one into
a bare soil or, sometimes, a "mulched" - i.e. covered by a thin plastic film - soil.
Generally speaking, a transplanting machine is equipped
with a plant feeding unit, usually in the form of a conveyor belt; shares or equivalent
means to produce a furrow in the soil; possibly a device for drilling the mulching
film; a distributor disposed to put the plants into the furrow. These operations
are to be performed in a very quick and precise manner, without damaging the plants;
in particular, it is of a great importance for taking root and growth that a plant
is well positioned into the furrow.
A known type of transplanting machine (patent
) is equipped with a "cup" distributor, wherein a certain number of cups
are carried by an articulated chain, and each cup is adapted to contain a plant
with the respective cubic clod.
The chain works between two gears, and the cups are connected
thereto by means of a system adapted to keep them parallel to one another: in practice,
each cup is connected to the chain by means of a side pin passing through a bush
which is integral with one link of the chain; a slide is associated to the free
end of said bush; the cups transiting around each gear are kept parallel by said
slide, through suitable guides and tracking members.
The cups are distanced by a given number of chain links,
which is a function of the desired planting distance.
Each cup basically consists of an upper portion, with a
gap for inserting the plants, and of a lower portion formed by two lateral walls
hinged on the upper portion of the cup, and connected by a spring and hinge system
enabling a joint movement thereof. The walls have a lower end with a serrated blade,
which facilitates the insertion of the cup directly into the soil or into the furrow
produced by the share, and enables to cut the mulching film, when provided. For
a more efficient operation on a mulched soil, it is known to add a further blade
fixed to the upper portion of the cups and independent of the side walls.
Each cup further comprises a pair of shaped walls, more
internal with respect to the side walls, that perform the function of retaining
the plants. By means of a suitable mechanical engagement, said shaped walls are
directly opened by the opening of the external ones, but with a small delay.
Near the soil, a cam controls the opening of the cup, the
external walls produce a furrow, and the inner walls, opening with a slight delay,
drop the plant into said furrow.
According to this system, which is sometimes referred to
as "pelican", each cup performs both operations of producing the furrow (and possibly
cutting the plastic film), and leaving the plant in the desired point.
There are, however, certain drawbacks: first, the plants
are dropped from a height typically around 5 or 6 centimetres: this is a small but
not insignificant drop, which may be sufficient to cause a slight tilting of the
plants. Problems arising therefrom are essentially that verticality of the plants
is not guaranteed and, above all, it may result in a bad adherence of the plants
to the lower surface of the furrow, leaving a certain air gap, below the plant,
that makes growth more difficult.
Another drawback is that the transplanting distance is
determined by the distance between the cups on the conveying chain, and can therefore
be modified only by removing or adding cups, which is a major intervention and requires
a significant machine downtime.
Furthermore, when working on a mulched soil, the known
cup distributors generally cut the film in a direction longitudinal to the furrow,
with a divaricated T-shaped cut, simultaneously inserting the plant that, some times,
may remain stuck to the plastic film. Because of this cutting action, the strips
of the cut plastic film may knock against the plant and damage it, especially in
strong wind conditions; the film strips are also an obstacle to visual inspection
of the correct position in the soil and make irrigation less effective.
Another disadvantage is that the cup transplanting machines
cannot reach very high operating speed, all the above drawbacks being more evident
as speed increases.
Further prior art is found in
from the same applicant. It discloses a distributor provided with a pickup
system for the cubic clods by means of two rotors elastically mounted on both sides
of the end section of the conveyor belt, disposed to cooperate with a gripping member
formed by two moving walls located on the sides of the conveyor belt and provided
with a pneumatic drive.
An electronically controlled hydraulic motor provides intermittent
action of the rotors, which are fitted with suitable transverse tabs to increase
their grasping capacity. Substantially, the rotors have the task of grasping the
clod (with corresponding plant) at the output of the conveyor belt and take it into
the furrow, while the gripping member acts as a stop means for the other plants
on the conveyor.
This type of distributor is faster than a cup distributor
and is very precise in positioning the plants; nevertheless, it is not suitable
for working on mulched plots, mainly because the plant is inserted into the furrow
with an oblique trajectory relative to the soil.
The object of the invention is to overcome these and other
drawbacks affecting the prior art, and in particular: to achieve a more precise
positioning into the soil or furrow, avoiding any fall of the plants; to obtaining
a good verticality and adherence to the soil; to adjust the transplanting distance
a simple and fast manner, without mechanical intervention (dismantling and reassembling
of the cups); to work also on mulched terrains, avoiding the above mentioned drawbacks
due to the contact between the plant and the cutting strips of the mulching film.
The objects are achieved by an automatic distributor for
transplanting machines of plants rooted in clods, comprising a feeding device for
the plants and means for making at least a transplanting furrow in the soil, characterised
by: a first pickup system disposed to pick up the plants individually from said
feeding device and take them to an intermediate position; retaining means disposed
to temporarily keep the plants in said intermediate position; a second pickup system
disposed to pick up the plants from said intermediate position and take them into
said transplanting furrow.
The feeding device consists, for example, of a conveyor
belt, equipped with movable stop means for stopping the column of clods loaded on
the belt, during the pickup action performed by said first pickup system. Said stop
means are obtainable with a pneumatically controlled moving screen, mounted laterally
on the end part of the conveyor belt.
Preferably, the first pickup system comprises a tool adapted
to perform an alternate come-and-go movement between the outlet of the feeding device
and said intermediate position; more preferably, the tool is moving on a trajectory
that is substantially an arc according to a fulcrum point.
Another aspect of the invention provides for the second
pickup system comprising a transplanting tool, with a linear movement and an almost
vertical trajectory between the intermediate position and a transplanting position
into the furrow; preferably the transplanting tool is guided by two parallel arms,
or connecting rods, substantially defining an articulated parallelogram structure.
According to further aspects of the invention, the tools
are operated by a wheel, powered by a hydraulic motor with an on-off solenoid value
or similar system. More in detail, the aforementioned wheel carries an eccentric
connecting rod, to operate the articulated parallelogram of the transplanting tool;
the pickup tool is also suitably connected to said parallelogram to obtain a coordinated
joint movement of the two tools.
In a particularly preferred embodiment, the pickup tool
and the transplanting tool are provided with pincer-like grasping means, operated
by pneumatic jacks, to clamp on both sides the clods of earth where the plants are
The distributor, as better explained below, is advantageously
provided with sensors for coordinating the operation of the various mechanical members;
preferably there is at least a sensor to monitor the clods arriving at the conveyor
belt outlet, and a sensor suitable for detecting the position of the tools.
The sensor for monitoring the arrival of clods is preferably
in the form of a movable abutment at the outlet of the feeding device, which can
be moved by the arriving clod thereby actuating an electronic sensor.
The position of the tools is detected, for example, by
a proximity sensor detecting the angle of rotation of the control wheel. The signal
from said sensor can be used to operate the pneumatic actuators of the distributor,
in particular of the pickup grippers mounted on the tools, and of the clods retaining
The retaining means of the clods in the intermediate position
are made, in a preferred embodiment, with a pneumatically-operated moving abutment
in cooperation with a fixed abutment.
The distributor can be designed to work on a bare soil
or also on a soil covered with plastic film (mulched). In this last case, it comprises
a further tool for drilling the plastic film, synchronised with the above described
tools for handling the plants.
In a preferred embodiment of the drilling tool, said tool
is shaped substantially as a "U" facing forward in the running direction, and provided
with an extracting lever to direct the plastic offcut of the film downwards and
towards the running direction, on the side facing the soil, thus folding the film
and opening a window, preferably a square window, without cutting strips being exposed
and in contact with the plant. This operation is encouraged by a suitable conformation
of the upper back of the share.
The distributor comprises electronic control means to manage
the joint operation of several distributors mounted on a single machine, as will
be explained below.
Another aspect of the invention is a transplanting machine
provided with a plurality of above disclosed distributors. The distributors are
mounted on a frame, carried on a front roller with adjustable height to determine
the working depth; the whole is fixed frontally on a parallelogram with a wheeled
side frame. The machine may be powered by a suitable engine, or designed for use
with an agricultural tractor or another means of traction.
Preferably, the distributors are aligned in a row; each
distributor has a dedicated hydraulic motor unit for driving the pickup tool and
transplanting tool, whilst one further, common hydraulic motor is provided to drive
the drilling tools of the plastic film. The hydraulic motors are controlled by independent
on/off solenoid valves, but their operation is coordinated to maintain synchronism
between the drilling of the plastic film and the handling of the plants.
More in detail, the transplanting machine comprises a signal
generator for providing a signal correlated to the distance covered by the machine,
e.g. a pulse generator fixed to the frontal roller or to the supporting wheels;
the machine is further equipped with a decoding card and a numeric control keypad
or equivalent device for setting the operating parameters, including the transplanting
The decoding card is able to detect the pulses from the
generator, thus measuring the distance covered by the machine, and to make a comparison
with the user-defined settings. The hydraulic motor of the drilling tools is controlled
by the card according to this comparison; the pickup and transplanting tools of
each single distributor are thus synchronised with the drilling action on the plastic
film, in such a way that the plant is centered into the window of said film.
According to a preferred embodiment, a sensor is provided
to detect rotation of the shaft of the drilling tools. The electronics of each single
distributor receives a signal from said sensor and, with a possible phasing delay,
controls the hydraulic motor of the pickup and transplanting tools mounted on the
distributor. The pneumatic part (grippers for the clods) is in turn synchronised
by a signal provided by the proximity sensor mounted on the control wheel of the
The machine is thus able to arrange the plants according
to the set transplanting distance, and to produce parallel rows or parallel staggered
rows also known as "quincuncial" rows.
The positioning of the clods is much faster and more accurate
compared to known machines, due to the two separate systems for moving the clods,
and in particular to the transplanting tool laying the plants one by one directly
in the furrow, rather than dropping them. The clods are released in a perfect vertical
position, thus ensuring the best adherence to the lower plane of the furrow and
therefore the best taking root.
The movement of the transplanting tool is a translation
with no rotational component between the intermediate position and the actual transplanting
position in the furrow, then it enables to release the plant in a perfect vertical
arrangement and at a speed which is also substantially vertical, to the advantage
of correct positioning of the plant.
The transplanting distance and/or the arrangement of the
plants (for example parallel or staggered rows) can easily be modified and without
having to dismantle or reassemble parts of the machine.
In practical terms, it will be sufficient to set the desired
transplanting distance on the numeric keypad.
On a mulched soil, the above disclosed cutting tool creates
an opening in the plastic film that is intended to receive the plants, folding the
cut strip towards the interior; all this enables correct placement and visual inspection
of the clod into the furrow, preventing the contact between the plastic film and
the plant, which is potentially hazardous for the latter, promoting irrigation from
These and other features of the invention will become clearer
from the more detailed description set out below, with the help of drawings that
show a preferred embodiment thereof, illustrated by way of non-limitative example,
- Fig. 1 is a schematic side view of a distributor according to the invention;
- Figs. 2 and 3 show the distributor in Fig. 1 in successive operating phases;
- Figs. 4 and 5 show some details of the conveyor belt of the distributor of Fig.
1, wherein Fig. 4 is a top view and Fig. 5 is a side view;
- Figs. 6 and 7 show further constructional details and refer in particular to
the moving members for moving the clods of the distributor of Fig. 1.
Referring now to the figures, an automatic distributor
for transplanting machines is illustrated that is designed for stand-alone operation
or as a modular unit of a transplanting machine with several distributors, having
a running direction M (Fig. 1) on the soil.
The distributor comprises a feeding device for plants,
shown as P, that are rooted in cubic clods Z. Said feeding device, in practice,
consists of a conveyor belt 1 with manual loading by some operators.
The distributor essentially comprises a pickup tool 2,
suitable for moving the plants individually from the conveyor belt 1 to an intermediate
position; means for keeping the plants in said intermediate position, which in the
example are achieved by a fixed abutment 4 cooperating with a movable abutment 4;
a transplanting tool 5, suitable for grasping the plants in the intermediate position
and take them to the final transplanting position.
The distributor is then provided with front shares 8, or
equivalent means, acting when advancing in said running direction M, normally drawn
by a tractor or agricultural vehicle. The shares 8 produce a furrow in the soil
wherein the plants are placed, substantially through the joint operation of said
tools 2 and 5.
In order to work on mulched terrains, that is covered with
a plastic film shown as F, the distributor also comprises a further tool 6 adapted
to perforate the said plastic film F.
The distributor mechanisms, which will be disclosed better
below, are mounted on a frame plate 7 acting as a support.
In greater detail, the feed belt 1 is fitted with side
retaining screens 10 to form substantially a moving channel inclined downwards and
towards the direction M.
At the end portion of the belt 1 there is a movable screen
11 to clamp the clods Z laterally and stop the plants currently loaded on the belt.
Said movable screen 11 (Fig. 4) is hinged on a rotating fulcrum 13 and is operated
by a pneumatic jack 14. It may leave the clods Z free to advance on the conveyor
belt (Fig. 4(a)) or stop them against the opposite screen 10 (Fig. 4 (b)) by clamping
them on the sides.
The length of the screen 11, as can be seen in Fig. 1,
is such as to leave free the first clod of the queue, shown as Z", so that said
clod Z" can be picked up by the tool 2.
At the outlet of the belt 1, there is a further movable
stop abutment 12, hinged on a rotating fulcrum 15 and moved by a pneumatic jack
The movable abutment 12 has a flap 17, which faces the
clods loaded on the belt 1 and is free to rotate on a fulcrum 18. The flap 17 is
arranged to excite, by rotation around said fulcrum 18, an electronic sensor 19
positioned in the immediate vicinity (Fig. 5); the flap 17 is preferably L-shaped,
as in the figure.
It should be noted that the flap 17, in cooperation with
the sensor 19, creates a system for detecting the arrival of the clods Z, providing
a signal when the first clod (Z" in Fig. 1) reaches the end of the belt 1 and is
ready to be picked up by the tool 2.
The pickup tool 2 is connected to the frame plate 7 through
a fulcrum pin 20 and is arranged to follow an alternate coming and going movement
with a substantially arc-shaped trajectory between a pickup position of the plants
(Fig. 1), and a release position thereof between the fixed abutment 3 and the movable
abutment 4 (Fig. 2).
The transplanting tool 5 is, on the other hand, moved between
the intermediate position of the clods and the transplanting furrow produced, in
the example, by the share 8.
The tools 2 and 5 are operated in a joint and coordinated
manner by a geared wheel 21 which, in turn, is operated by a drive wheel 22 preferably
connected to a hydraulic motor. A proximity sensor 23 is mounted near the wheel
21 to detect the rotation angle of said wheel.
The movement system of the tools 2 and 5 is shown is greater
detail in Fig. 2. The wheel 21 carries a connecting rod 25 by an eccentric pin 24;
said connecting rod 25 is acting on an articulated parallelogram structure, substantially
formed of two parallel arms 26 and 27 hinged on the frame 7 and on the body of the
transplanting tool 5. A further connecting rod 28 is provided to link said articulated
parallelogram structure, and more in particular the arm 26, to the body of the pickup
This movement system makes the transplanting tool 5 perform
a rectilinear movement with no rotational component, with an almost vertical trajectory;
this movement is particularly advantageous for the purposes of correct positioning
of the plants in the furrow.
In a preferred embodiment, the pickup tool 2 (Fig. 6) consists
substantially of a small frame 30, with a first crosspiece 31 that supports a pneumatic
jack 32, and a second crosspiece 33 that supports two pickup members 34. Said pickup
members 34 are represented by thin metal screens, that are movable between the positions
of Fig. 6 a) and b) as indicated by the arrows, and are mounted on supports coupled
by a gear sector. The jack 32 is connected to one of said supports by means of a
link arm 35, and owing to the gear sector the screens 34 can be simultaneously operated.
The transplanting tool 5 is shown in greater detail in
Fig. 7: it essentially comprises two metal screens 37 pivoted on a small bearing
frame 38 and moved by means of a pneumatic jack 36. A gear-sector coupling, similar
to the one disclosed above, ensures simultaneous opening and closing of the two
screens 37. Fig. 7 shows a clod Z held by the tool and with a plant P rooted therein.
The bearing frame 38 is fixed to a plate 39 (Fig. 2) where
the ends of the arms 26 and 27 are hinged.
Substantially, Figs. 6 and 7 show a preferred operation
for the tools 2 and 5, handling the clods Z by clamping them on side faces by means
respectively of the movable screens 34 and 37.
The clods are retained in the intermediate position, between
the two tools, by the movable abutment 4 in cooperation with the fixed abutment
3. Preferably, said movable abutment 4 consists of a metal plate, moved by a pneumatic
jack 40 (Fig. 1) with a quick rotation around a fulcrum 41.
The movable abutment 4 can be displaced to lock one of
clods Z against the fixed abutment 3 (position of Fig. 3), or to free it for handling
by the transplanting gripper 5 (position of Figs 1 and 2).
The tool 6 is mounted on a support 50 guided by two parallel
arms 51 and 52 hinged on the lower portion of the frame 7. Said tool 6 is operated
by a geared wheel 53 with a connecting rod 54 acting on said support 50; the wheel
53 is in turn operated by a drive wheel 55 powered by a hydraulic motor (not shown).
Substantially, the wheel 21 controls the handling and releasing
of the plants, whilst wheel 53 controls the perforation of the mulching film F.
The hydraulic motors of wheels 21 and 53, by means of the respective drive wheels
22 and 55, are independent of one another, but are controlled in a synchronised
manner by means of on/off solenoid valves disposed to open and close the pressurised
oil flow to the motors.
The tool 6, from a constructional point of view, is shaped
like a "U" with the two tips pointing in the travel direction M, and consists of
multiple cusps adapted for perforating the film F. The perforation of the film F
is made in adherence to the share 8, which has a blind back 56 (Fig 1), except for
the perforating zone. The film runs adhering to the back 56 of the share, and during
the cutting operation the part at the perimeter of the drilling zone provides sufficient
resistance to enable the perforation by tool 6.
The tool 6 is furthermore provided with an extracting lever
57 to direct the plastic offcut of the film F downwards and in the travel direction
of the side facing the plot, thus enabling the opening of a window for positioning
the plant and without leaving strips exposed to the exterior, in particular to the
wind, which may damage the plants. The window so obtained on the film F is preferably
a square window.
The extracting lever 57 is pivoted at one end 64, facing
the travel direction M, and is operated by a rod 58 by means of a short connecting
rod 65. Said rod 58 connects to the wheel 53 with a square 59, with an eccentric
drive, and with a return spring 60. The movement of the tool 6 is apparent from
the comparison between Fig. 1 and Fig. 2.
The film F unwinds from a reel 61; a drilling roller 62
is provided for making holes in the film F for the passage of air. A tensioning
roller 63 is positioned just upstream of the perforating tool 6 (Fig. 1).
The disclosed distributor is normally a part of a transplanting
machine that comprises a plurality of distributors, e.g. three or four units, mounted
on a motorized frame or on a carrying frame to be hooked to a tractor.
Preferably, the distributors are alongside one another
and aligned together; each distributor is provided with a hydraulic motor to operate
the wheel 22, that is to operate the pickup and transplanting tools 2 and 5; the
wheels 55, on the other hand, are splined on a shaft, for example using hexagonal
shaft and bushes, and operated by a further hydraulic motor which is in common for
The hydraulic motors are controlled by independent on/off
Adoption of a dedicated hydraulic motor for the tools of
each distributor is advantageous, inasmuch as it enables the tools to be driven
in the exact moment when the plant reaches the end of the belt 1, triggering the
sensor 19 by means of the flap 17. This solution prevents tools 2 and 5 from moving
empty and/or clamping a clod in an incorrect way, for example too close to the edges.
The transplanting machine also comprises an electronic
control system (not shown), by means of a pulse generator fixed e.g. to the front
roller or to the supporting wheels; an electronic decoding card adapted to detect
the pulses from the generator; a numeric control keypad. The card is suitable for
detecting the pulses of the generator and to compare them with a preset value inserted
by the user through said keypad.
A further proximity sensor, not shown, (or a pair of sensors)
detects the rotation of the splining shaft of the wheels 55.
Said sensor provides a signal that can be used by the distributors
to start the hydraulic motor of the wheel 22. The pneumatic jacks are then controlled
by the sensor signal 23.
For this purpose, each distributor is provided with a dedicated
electronics and preferably also with a fine adjustment trimmer. The trimmer enables
to set a certain delay between the receipt of the rotation signal from the shaft
of wheels 55, and actual operation of tools 2 and 5, to compensate for inertia of
the hydraulic/pneumatic part, for example the valve response time, which is not
The compressed air and the pressurised oil are supplied
by a compressor and by a pump, powered for example by the cardan shaft of the tractor.
Both the pump and the compressor can be on the transplanting machine or the traction
The distributor operates as follows.
Fig. 1 shows a clod Z', and the respective plant, held
in the tool 5, whilst a second clod Z" is near the movable abutment 12 and ready
to be grasped by the tool 2.
The clod Z", when reaching the end of the belt 1, moves
the flap 17 to the position of Fig. 5 b), thus exciting the sensor 19 that detects
the exact time of "arrival" of the plant. The signal of said sensor 19 causes the
side gripper 11 to close immediately, turning to the position of Fig. 4 b) and holding
the second and further plants queued on belt 1.
Simultaneously, the electronic control system closes the
gripper 34 of the tool 2 by means of the respective jack 32, whilst the stop 12
rotates around the fulcrum 15 to open and enable the passage of the clod Z".
The solenoid valve of the hydraulic motor of the wheel
22 is opened, making the wheel 21 to perform approximately half a revolution in
anti-clockwise direction (seen in Fig. 1); the distributor then goes to the position
of Fig. 2.
This movement, by means of the disclosed kinematic mechanisms,
causes the lowering of the transplanting tool 5, down inside the furrow obtained
by the share 8, and through the window in the plastic film F opened by the tool
6; simultaneously, the pickup tool 2 takes the clod Z" to the parking position between
abutments 3 and 4.
A comparison between Figs. 1 and 2 shows that simultaneously
with the movement of the tools 2 and 5, the wheel 53 performs a portion of an anti-clockwise
revolution, driving the tool 6 and the extractor 57. The tool 6 cuts the plastic
film F, which runs underneath the tool because the machine is advancing, folding
the cut strip inwardly. The operation does not create offcuts and does not leave
any plastic strips in contact with the plants.
When the transplanting tool 5 reaches the end of the lower
stroke (Figs. 2-3), the system commands the opening of the gripper by means of the
jack 36, placing the clod on the bottom of the furrow, in a vertical position and
with the leaf pointing upwards, outside the plastic film F.
The positioning system does not make the plant fall from
some centimetres, as known machines do; furthermore, the tool 5 performs a translation
movement with no rotation components that maintains the verticality of the plant.
When screens 37 open, the plant has a completely vertical orientation and a speed
close or equal to null; all this enables to achieve the aforementioned advantages
of a precise positioning in the furrow and good adherence between the cubic clod
and the furrow.
Subsequently (Fig. 3) the movable abutment 4 closes, clamping
the clod Z" against the contrasting abutment 3, whilst the wheel 21, with another
half revolution in the anticlockwise direction of Fig. 1, lifts up the tool 5 and
simultaneously returns the tool 2 to the belt 1. The tool 2 grasps the clod Z" and
the movable abutment 4 opens, returning to the situation of Fig. 1 wherein the machine
is ready to start a new cycle.
The above phases are performed in a very rapid succession,
with work cycles that are synchronised, in practice, with the action of the drilling
The main card of the machine operates the hydraulic motor
of the drilling tools 6. The individual distributors, thus, on the basis of the
signal received by the proximity sensor on the splining shaft of the wheels 55,
control the hydraulic motor of the wheel 22 that drives the tools 2 and 5. The pneumatic
jacks are in turn controlled by the sensor signal 23, and are thus synchronised
with the movement of the tools.