Nursery plant digger

A nursery plant digger apparatus designed to be pulled behind a typical tractor and used to harvest bare root plants grown in long, parallel rows in a field. The digger apparatus includes a horizontally aligned tool bar attached to the rear of the tractor. Extended laterally from one side of the tool bar is an adjustable, U-shaped scoop which is dragged in the soil as the tractor is driven in a forward direction on the field. The angle and position of the scoop relative to the tool bar may be adjusted to control the digging depth of the scoop. During normal use, the scoop is adjusted to travel under the plant's deepest root. A shaking grate is pivotally attached to the rear edge of the scoop. During use, a hydraulic motor is connected to an eccentric which causes the grate to shake downward to dislodge soil delivered to the grate as the tractor moves in a forward direction.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to nursery plant diggers and, more specifically, to 
nursery plant diggers designed to remove plants from the soil and produce 
bare root plants for easy transport and replanting. 
2. Description of the Related Art 
Large nursery plant growers often grow seedlings in long, parallel rows in 
large fields. When the plants grow to a desired height, they must be 
harvested and transported to a nursery for direct sale to the public or to 
an intermediate wholesaler or to a nursery for resale. Depending upon the 
type, some plants are harvested with bare roots while others are harvested 
with a root ball. 
When harvesting bare root plants, each plant must be gently removed from 
the soil and then shaken to remove the soil from its roots without 
damaging the plant. The plants are then bundled together and transported 
to a desired resale location. 
Typically, nurseries use the bucket on a standard tractor, a large nursery 
tree remover apparatus (see U.S. Pat. No. 4,305,213) or a c-shaped ring 
mounted apparatus pulled by a tractor (see U.S. Pat. No. 4,332,093) to 
harvest plants. Unfortunately, none of these apparatus by themselves 
produce root bare plants. In order to do so with these apparatus, the 
plants must be manually shaken to remove the soil from the roots. Needless 
to say, this additional act adds to the expense of harvesting the plants. 
What is needed is an apparatus that can be easily attached to existing 
machinery used by a nursery grower that can be used to harvest plants 
grown in long parallel rows, which also removes the soil from the roots, 
and then deposits the plants in an orderly manner so they can be easily 
bundled together for delivery. 
SUMMARY OF THE INVENTION 
It is an object of the invention to provide an apparatus for gently 
harvesting plants grown in long, parallel rows in a field. 
It is another object of the invention to provide such as apparatus that 
removes the soil from the roots of plant. 
It is further object of the invention to provide such an apparatus that 
deposits the root bare plants in an orderly manner for bundling them 
together. 
It is a still further object of the invention to provide such an apparatus 
that can be easily attached a to standard tractor used by a nursery grower 
and is economical to manufacture. 
These and other objects are met by providing a digger apparatus capable of 
being pulled by a typical tractor and used to harvest bare root plants 
grown in long, parallel rows in a field. The digger apparatus includes a 
horizontally aligned tool bar attached to the rear of the tractor via a 
three point hitch assembly. Attached to the distal extending end of the 
tool bar is a U-shaped scoop which is pulled through the soil as the 
tractor is driven in a forward direction in the field. The angle and 
position of the tool bar can be adjusted via a height adjustment means 
disposed between the tractor and tool bar so that the leading edge of the 
scoop travels through the soil slightly under the plant thereby lifting 
the plant from the soil as the tractor moves in a forward direction over 
the soil. 
As the tractor continues to move in a forward direction, plants deposited 
into the scoop are forced out of the scoop and onto a shaking grate. The 
shaking grate is pivotally attached along its front edge to the rear edge 
of the scoop. During use, a shaking great means is connected between the 
shaking and the tool bar which causes the shaking grate to move up and 
downward to dislodge the soil from the roots of plants deposited on the 
shaking grate. In the embodiment described herein, the shaking means 
includes a hydraulic motor with an eccentric connected to its drive shaft. 
The eccentric is pivotally connected to the upper end of a rocker arm 
which is pivotally connected at its lower end to the shaking grate. When 
the motor is activated, the eccentric causes the rocker arm to move up and 
down thereby gently shaking any loose soil that clings to the plant's root 
ball. An adjustment means is also provided which enables the angle of the 
shaking grate relative to the scoop to be adjusted according to the 
hardness of the soil, the amount of rocks therein, and the plant's size 
and variety. As the tractor continues to move in a forward direction 
parallel to the row of plants, the harvested plants with their root balls 
soil free, exit the shaking grate and are deposited in an orderly manner 
for easy pickup.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S) 
Shown in the accompanying FIGS. 1-5, there is shown a digger apparatus, 
generally referred to as 20, designed to harvest bare root plants 92 grown 
92 in long, parallel rows 90 in a field. The digger apparatus 20 is 
designed to be pulled behind a typical tractor 8 having a three point 
hitch system 9 as shown in FIG. 1. The three point hitch system 9 includes 
a centrally located upper link connector 11 and two lower, side link 
connectors 13, 14. The height and angle of the three point hitch system 9 
is hydraulically controlled by the tractor's hydraulic system via the 
upper and lower links 11, 13, and 14, respectively. 
As shown in FIGS. 1 and 3, the digger apparatus 20 includes a horizontally 
aligned tool bar 21 attached to the tractor's three point hitch system 9. 
The length of the tool bar 21 must be sufficient to connect to the three 
point hitch system 9 and position the scoop 30, attached to the distal end 
22 thereof, transversely over the row of plants to be harvested which are 
located parallel and adjacent to the tractor. In the embodiment shown, the 
tool bar 21 is made of 4.times.8 inch steel rectangular tube material 72 
to 96 inches in length. The tractor's lower links 13, 14 are attached to 
two, spaced apart clamps 12, 17, respectively, attached to the tool bar 
21. The clamps 12, 17 may be selectively adjusted along the tool bar 21 so 
that the digger apparatus 20 may be used with a variety of three point 
hitch systems on different tractors. Located on the tool bar 21 between 
the clamps 12, 17 is an upward extending central clamp 19 which attaches 
to the three point hitches' upper link 11. During use, the tractor's 
hydraulic system is used to lower and raise the position of the tool bar 
21 with respect to the tractor or soil as shown in FIG. 4. 
Attached near the distal extending end 22 of the tool bar 21 is a motor 
mount 24. The motor mount 24 extends rearward and perpendicular from the 
rear surface of the tool bar 21. In the embodiment shown, the motor mount 
24 includes two side members 26, 28 and a rear member 29 welded together 
at their adjoining ends to form a partially enclosed structure that 
extends from the rear surface of the tool bar 21. An optional cover 25 
(shown in FIG. 1) may be attached to the motor mount 24 to protect the 
hydraulic motor 60 contained therein and to prevent injuries. 
Extending downward from the distal extending end 22 of the tool bar 21 is 
an adjustable, U-shaped scoop 30 which is dragged on the ground as the 
tractor 8 is driven in a forward direction on the field. In the embodiment 
shown, the scoop 30 is made of steel plate material and measures 
approximately 30 inches in length, 24 inches wide, and 16 inches deep. The 
inside leg of the scoop 30 is connected via bolts 31 to a flat plate 16 
welded to the laterally extending end 22 of the tool bar 21. By fixing the 
scoop 30 to the end of the tool bar 21 in this manner, the tractor's 
hydraulic system may be used to adjust the height and angle of the scoop 
30 relative to the soil. 
Located behind the scoop 30 is an adjustable shaking grate 40. The shaking 
grate 40 is pivotally attached along its leading edge 42 to the rear edge 
32 of the scoop 30 as shown in FIGS. 3 and 5. Formed on the leading edge 
42 of the shaking grate 40 are two, spaced apart forward extending arms 
44, 46 which engage the two complimentary arms rearward extending 34, 36 
located on the bottom surface of the scoop 30. A bolt 37 is used to 
connect the adjoining pair of arms 34, 44 and 36, 46 respectively 
together, thereby pivotally connecting the scoop 30 and shaking grate 40. 
The shaking grate 40 itself is made of steel and measures approximately 28 
inches in length and 20 inches in width. Three vanes 41 aligned 
longitudinally inside the shaking grate 40 are approximately 3 inches 
apart. 
Pivotally attached at one end to the inside wall of the shaking grate 40 
via a bolt and lock nut 52, 53, respectively, is a rocker arm 50. The 
rocker arm 50, as shown in FIG. 5, extends upward from the shaking grate 
40 and connects to an outer bearing 55 via four bolts 56. Projecting 
inward from the outer bearing 55 is an outer drive shaft 56 which attaches 
to the outer surface of an offset arm. The outer bearing 55 is connected 
to main drive shaft 61 on the hydraulic motor 60 located inside the motor 
mount 24. The central axis of the outer drive shaft 56 is offset from the 
central axis on the main drive shaft 61 thereby creating an eccentric 
which, in turn, causes the rocking action depicted in FIG. 5. In the 
embodiment shown, the rocker arm 50 has a longitudinally aligned cutout 51 
and two parallel rows of holes 54 formed on the opposite sides of the 
cutout 51 which enables the length of the rocker arm 50 to be adjusted on 
the outer bearing 55. By adjusting the length of the rocker arm 50, the 
angle of the shaking grate 40 may be adjusted. By adjusting the angle of 
the shaking grate 40, the lifting force exerted by the shaking grate 40 
may be adjusted to dislodge the soil from the plant's roots according to 
soil conditions, type and age of plant, and the soil depth of the rear 
edge 32 of the scoop 30. 
The hydraulic motor 60 has an inlet and outlet hydraulic lines 61, 62, 
respectively, which connect to the tractor's hydraulic system. A check 
valve 65, is provided on one of the lines 62, 63 so that the hydraulic 
fluid contained therein flows in only one direction. A switch located on 
the tractor near the operator may be used to control the hydraulic motor 
60 during use. In the preferred embodiment, the hydraulic motor 60 rotates 
in a clockwise direction and has 16.9 cubic inches of displacement per 
revolution The size of hydraulic motor 60 may vary depending on the size 
and amount of hydraulic pressure on the tractor's hydraulic system 
During use, the hydraulic motor 60 is activated which causes the drive 
shaft 62 to rotate. As the drive shaft 62 rotates, the outer offset arm 57 
rotates and causes the rocker arm 50 to move upward and downward. The 
upward and downward movement of the rocker arm 50 causes the end of the 
grate 40 to move in an upward and downward motion. 
Optional, adjustable legs 70, 75 are attached near the proximal end 18 of 
the tool bar 21 and to one of the rear members 29 of the motor mount 24, 
respectively. The legs 70, 75 and round surface of the scoop 30 are used 
to support the digger apparatus 20 in a horizontal position on the ground 
when not in use. This enables the operator to easily connect and 
disconnect the digger apparatus 20 from the tractor by himself or herself 
with no additional workers. The legs 70, 75 are lowered or raised via a 
turn nut 71, 76, respectively. 
After the digger apparatus 20 is attached to a tractor 8, the tractor 8 is 
then driven onto the field and in position adjacent to a row of plants to 
be harvested as shown in FIG. 2. The hydraulic system on the tractor 8 is 
then used to adjust the relative position of the tool bar 21 so that the 
leading edge of the scoop 30 initially cuts into the ground a depth 
slightly below the plant's deepest root. The angle of the tool bar 21 is 
also adjusted so that the scoop 30 remains at this depth in the soil as 
the tractor 8 moves in a forward direction during use. The length of the 
rocker arm 50 is also adjusted to adjust the angle of the shaking grate 40 
so that the soil is dislodged from the plant's roots. 
In compliance with the statute, the invention, described herein, has been 
described in language more or less specific as to structural features. It 
should be understood, however, the invention is not limited to the 
specific features shown, since the means and construction shown comprised 
only the preferred embodiments for putting the invention into effect. The 
invention is, therefore, claimed in any of its forms or modifications 
within the legitimate and valid scope of the amended claims, appropriately 
interpreted in accordance with the doctrine of equivalents.