Note: Descriptions are shown in the official language in which they were submitted.
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PARALLEL LINKAGE OPENER WITH ADJUSTABLE SPRING LOADED
PACKER WHEEL
This invention relates to an agricultural seeder in which seeds are
conveyed from a central hopper to a number of seeding elements carried upon a
frame with the seeds being ejected into the ground through a ground opener
provided on each of the seeding elements and rolled by a following packer
wheel.
BACKGROUND OF THE INVENTION
Seeders of this type have generally used either a knife or a cutting
sweep which is carried at each of the seeding elements by the frame so as to
cut a
furrow in the ground into which the seeds are deposited. The depth of seeding
is of
fundamental importance to the germination and should therefore be very
accurately
controlled. The seed must be properly placed a required spacing from the soil
surface and also taking into account soil surface moisture characteristics and
the
sub-surface moisture to obtain the optimum germination.
In many seeders the depth of seeding is controlled by mounting the
seeding element in fixed position on the frame and then by controlling the
height of
the frame relative to the ground as accurately as possible by providing a
frame
which can flex at different positions so the height of the frame varies to
follow as
accurately as possible the contours of the ground. However this approach has
of
course its limitations in that the frame necessarily must have some structural
stability
which thus limits its ability to totally follow the contours of the ground.
Thus some of
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the seeding elements will at various times provide a depth of seeding which is
too
deep and other times the depth will be too shallow.
Other commercially available seeding systems are provided in which
the seeding elements are individually mounted upon the frame so that they can
individually follow the contours of the ground.
SUMMARY OF THE INVENTION
It is one object of the invention to provide an improved seeder where
the seeding elements include a ground opener and a packer wheel on an element
which can float vertically relative to the frame.
According to one aspect of the invention there is provided an
agricultural seeder comprising:
a frame having at least one tool bar;
ground wheels for supporting the frame for transportation in a direction
of working movement across ground to be seeded;
a plurality of seeding elements each including a bracket mounted on
said at least one tool bar of the frame so that said plurality of seeding
elements are
arranged at spaced positions across the width of the frame for applying seeds
to the
ground as the frame is moved across the ground;
each of said plurality of seeding elements including a ground opener
for cutting a furrow into the surface of the ground;
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each of said plurality of seeding elements including a packer wheel
behind the ground opener for rolling along the ground at or adjacent to the
furrow;
each of said plurality of seeding elements being mounted on said at
least one tool bar for up and down floating movement relative to the frame
independently of the other seeding elements;
each of said plurality of seeding elements including a pair of parallel
arms connected to the bracket and extending rearwardly therefrom to form a
parallel
linkage for said up and down floating pivotal movement relative to said at
least one
tool bar to different angles of the parallel linkage relative to the ground;
each of said plurality of seeding elements including a rearwardly
extending support arm connected at a rear end of the parallel arms and
carrying the
packer wheel such that the packer wheel can move upwardly and downwardly
relative to said at least one tool bar;
a spring arrangement extending between a component connected to
said at least one tool bar and said parallel linkage and applying a downward
spring
force on said parallel linkage relative to said at least one tool bar on the
parallel
linkage and arranged to flex to provide said floating movement of said
parallel
linkage relative to said at least one tool bar to apply a downward force on
the
packer wheel, the spring arrangement being arranged such that the spring force
increases as the parallel arms pivot upwardly and decreases as the parallel
arms
pivot downwardly;
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and a control device arranged to raise and lower said at least one tool
bar relative to the ground so as to change the angle of the parallel linkage
relative to
the ground so as to change the downward spring force generated by said spring
arrangement.
As is well known, one of the function of the packer wheel is to act as a
gauge wheel, that is it is the main component for controlling the furrow
opener's
operating depth.
The control device to raise and lower the frame to control the packer
pressure can be operated using a number of different sensor arrangements. Thus
a
number of different arrangements are possible to adjust/control the force
applied on
the packer wheel by the frame, that is transferring load from the frame's
wheels onto
the opener assemblies. Some of these are:
a) sensing the actual force applied on the packer wheels, which
can b sensed at one of the packer wheels or at a plurality of packer wheels
and
averaged, that is a direct approach;
b) sensing the angle of the parallel linkage or the position of the
seeding element relative to the tool bar, that is an indirect sensing of the
actual force
applied on the packer wheel via geometric calculation to determine the force;
c) sensing the position of the frame relative to the packer wheel. It
is possible to mount a position sensor on the rocker shaft assembly which
controls
the height of the frame relative to the ground wheels to implement this
arrangement.
d) sensing the hydraulic pressure on the frame height control
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cylinder.
In all cases, the operator will be able to "dial-in" the desired down force
to be applied by the frame to the packer wheel assembly; the objective is to
have the
system maintain the down force constant in the field, eliminating variations
in
5 packing force when travelling from hard soil conditions to soft soils. Of
course the
total down force is shared between the individual seeding elements and their
packer
wheels, but typically this force is shared equally, except for individual
changes in
ground height which are averaged out amongst all of the packer wheels.
Preferably the frame is carried on front and rear castor wheels and the
height of the tool bar is controlled by operating a cylinder on the frame to
rotate a
rocker shaft on the frame to drive through linkages the height of the front
and rear
castor wheels relative to the frame so that the frame is maintained horizontal
as it is
raised and lowered. However other frame support arrangements can be used
provide the height of the frame is adjustable by moving the position or
orientation of
the wheels relative to the frame. Preferably the system is operate
symmetrically so
that the whole of the frame, typically carrying three or more parallel tool
bars is lifted
while being maintained horizontal. Arrangements of this type can be designed
by a
person skilled in this art.
Preferably the ground opener is carried on an arm which is
independently pivotal relative to the support arm carrying the packer wheel
for a
spring trip action of the ground opener to accommodate impacts with obstacles.
The
trip action generally does not include the packer wheel which can float over
the
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objects by the parallel linkage moving upwardly against the spring force. The
arm is
preferably pivotal relative to the rear pivot pin of a bottom one of the
parallel arms.
Preferably the bracket carries a bottom stop member for engaging one
of the parallel arms to halt downward movement thereof.
Preferably the parallel arms carry a link of the parallel linkage system
connected across rear pivot pins at the rear of the arms which link is rigidly
attached
to the rearwardly extending support arm carrying the packer wheel.
Preferably the link carries a support member for a rear end of a spring
which is deformed by the spring trip and wherein the arm of the ground opener
includes at its forward end a lever which pulls a forward end of the spring in
the
spring trip action.
Preferably the support member for the rear end of the spring forms a
part of a brace for the support arm of the packer wheel.
In accordance with another feature, the packer wheel includes a
scraper strap extending rearwardly and over the wheel so that a rear end of
the
strap engages a peripheral surface of the packer wheel.
In accordance with another feature, the ground opener includes a
shank carried in a sleeve and extending downwardly from the sleeve for
supporting
a cutter at a bottom end of the shank and wherein the shank is adjustable
longitudinally of the sleeve. Preferably the adjustment is provided by the
shank and
the sleeve each including a saw tooth rack longitudinally thereof so that the
racks
are interengaged at longitudinally adjustable positions therealong. There is
then
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provided a manually operable cam which is movable to a locked position in
which
the racks are forced into engagement and to a released position in which the
racks
are free for longitudinal adjustment. Preferably the cam is operable by a
spring
handle which is latched into position in the locked position.
According to a second aspect of the invention there is provided an
agricultural seeder comprising:
a frame having at least one tool bar;
ground wheels for supporting the frame for transportation in a direction
of working movement across ground to be seeded;
a plurality of seeding elements each including a bracket mounted on
said at least one tool bar of the frame so that said plurality of seeding
elements are
arranged at spaced positions across the width of the frame for applying seeds
to the
ground as the frame is moved across the ground;
each of said plurality of seeding elements including a ground opener
for cutting a furrow into the surface of the ground;
each of said plurality of seeding elements including a packer wheel
behind the ground opener for rolling along the ground at or adjacent to the
furrow;
each of said plurality of seeding elements being mounted on said at
least one tool bar for up and down floating movement relative to the frame
independently of the other of said plurality of seeding elements;
wherein the ground opener includes a shank carried in a sleeve and
extending downwardly from the sleeve for supporting a cutter at a bottom end
of the
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shank where the shank is adjustable longitudinally of the sleeve; and
wherein the shank and the sleeve each include a respective saw tooth
rack extending longitudinally of the sleeve and the shank so that the racks
are
interengaged at longitudinally adjustable positions therealong;
and wherein there is provided a manually operable cam which causes
relative movement of the shank and the rack carried thereon relative to the
sleeve
and the rack carried thereon in a direction transverse to the sleeve and to
the shank
from a locked position in which the racks are forced into engagement [and] to
a
released position in which the racks are free for longitudinal adjustment.
The arrangement described herein can provide one or more of the
following features and advantages:
1. Seeding depth is maintained independently from adjusting
the
position of the drill frame, when in general operating position for engaging
tool in the
soil, as a result of the independent motion of the parallel linkage;
2. The parallel linkage allows to maintain the vertical relationship
between the hoe opener point and the packer wheel elevation
3. The spring loaded linkage is designed to apply a known down
force on the packer wheel via an adjustment of the drill frame elevation from
the
ground surface so that the control system can be operated to "dial-in" a set
packer
down force;
4. The design allows for a desirable range of packing down force
from less than 70 lbs to over 250 lbs;
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5. The operation depth or seeding depth for the opener is adjusted
without any tools, via a double rack assembly held in place by a spring loaded
cam
system;
6. The actual seeding depth is solely achieved by adjusting the
vertical position of the opener relative to the packer wheel's elevation;
7. The packer wheel elevation is not adjusted;
8. The assembly comprises only a single furrow opener;
9. The furrow opener is allowed to trip independently from the
overall assembly via its own heavy spring loading, if required as a result of
striking a
stone or other obstacle with a trip force which can be adjustable;
10. The use of this parallel linkage is not limited to using a hoe
opener; other soil engaging tools could be used instead
11. The assembly includes an infinitely adjustable scraper for the
packer wheel.
12. It can provide adjustable packing pressure which is delivered
through twin springs at the seeding element and regionally by hydraulic
pressure set
at the cab which controls the pressure supplied to the hydraulic cylinders
controlling
the height of the frame.
13. The basic setting for each shank is set at the factory which
means re-setting is not necessary at the frame and individual hydraulic rams
are not
necessary and are not used at the seeding elements.
14. The seeding depth is set in small increments using a simple
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manual setting arrangement. This makes it sufficiently easy for depth
adjustment to
be made that it overcomes the general reluctance to change for different crops
or
different soil conditions.
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BRIEF DESCRIPTION OF THE DRAWINGS
One embodiment of the invention will now be described in conjunction
with the accompanying drawings in which:
Figure 1 is a side elevational view of one seeding element of a seeder
10 according to the present invention.
Figure 2 is an isometric view from the rear and one side of the seeding
element of Figure 1.
Figure 3 is an isometric view from the rear and the other side of the
seeding element of Figure 1.
Figure 4 is a top plan view of the seeding element of Figure 1.
Figure 5 is an isometric view from the front and one side of the seeding
element of Figure 1.
Figure 6 is a side elevational view of a seeder according to the present
invention including the seeding element of Figure 1.
Figures 7, 8 and 9 are a side elevational view of the seeder of Figure 6
including the seeding element of Figure 1.
In the drawings like characters of reference indicate corresponding
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parts in the different figures.
DETAILED DESCRIPTION
Turning firstly to Figure 6 the whole of the seeding apparatus is shown
in side elevation and comprises a main central frame 10 mounted for movement
across ground to be seeded on a front wheel assembly including a pair of
ground
wheels 11 and a rear pair of spaced ground wheels 12.
Both front and rear wheels form dual castor wheels. The frame
includes a series of side by side sections (not shown) which can fold in
conventional
manner and each is individually supported by ground wheels (not shown) which
operate simultaneously with the wheels 11 and 12.
The frame is generally rectangular and formed from longitudinal and
transverse beams in conventional manner. A forward part of the frame includes
a
hitch 13 for coupling to a towing vehicle. The front wheels 11 are carried on
a
support 11A from a forward end of the frame 10. The rear wheels 12 are carried
on
a support 12A from a rear end of the frame 10.
The details of the frame structure are not described as these will be
apparent to one skilled in the art and do not form an important part of this
invention.
The ground wheels 11 and 12 are mounted on the supports 11A and
12A so that they can be raised and lowered in height relative to the frame 10.
Thus
the support 11A includes a pair of parallel links 11B, 11C connected at a rear
end to
a forward end 10A of the frame and extending forwardly therefrom to a castor
support 11D of the castor wheels 11. A lever 11E acts to pivot the parallel
links 11B,
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11C about the rear pivot so as to raise and lower the wheels 11 relative to
the frame
10. The lever 11E is drive in pivotal movement by a link 15A of a drive system
15
operated by a cylinder 15B and a lever 15C connected to a rock shaft 15D on
the
frame.
The rock shaft 15D also drives a link 15E which pushes down on a
lever 15F which carries the rear wheels 12 and is pivotally connected to the
frame
by a bracket 15G.
In Figure 6, one of the seeding elements is illustrated and indicated at
30. These seeding elements trail behind a transverse tool bar 31 of the frame
10 and
10 arranged alternately on forward and rearward tool bars 10B, 10C, 10D in
conventional manner so as to provide a seeding action across the full width of
the
frame while allowing sufficient space in between the individual seeding
elements on
each of the transverse tool bars. The remaining seeding elements are omitted
from
the frame structure in Figure 6 for convenience of illustration.
The seeds and, if required, fertilizer are carried through ducts (not
shown) for the distribution and splitting action by an air stream generated by
a fan
(not shown) carried on the frame at a suitable location.
The rock shaft acts to simultaneously drive all of the ground wheels to
lift or lower in unison so that the frame 10 remains horizontal as it is
lifted and
lowered relative to the ground. Thus all of the tool bars 10B, 10C, 10D are
supported at a common distance from the ground which is changed by operation
of
the rock shaft 15D.
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One of the seeding elements 30 is illustrated in detail in Figures 1
through 5. The remaining seeding elements are identical to the one
illustrated.
On a rear vertical face of the tool bar 10A is mounted a vertical plate
32 which si clamped to the tool bar 10A by conventional loops 31. The vertical
plate
includes a bottom portion 32A inclined forwardly and downwardly from the
bottom of
the vertical plate to a position underneath the tool bar 10A.
The seeding element further includes a parallel linkage 33 defined by
upper and lower parallel arms 34 and 35. Each of the arms is formed by a
channel
member with side walls which provide supports for transverse pivot pins 34A
and
35A at the front and 34B and 35B at the rear. The front pin 34A of the upper
arm 34
is pivotally mounted on the vertical plate 32 and the front pin 35A of the
lower arm
34 is pivotally mounted on the inclined plate portion 32A.
Across the rear pivot pins 34B and 35B is connected a rear link 38
which also is channel shaped and includes side walls 38A and 38B connected to
the
pivot pins. Thus the link and the parallel arms form a parallel linkage which
controls
movement of the link 38 so that it moves vertically as the arms 34 and 35
pivot about
their respective pins 34A and 35A.
A stop member 37 is connected to the inclined portion 32A and
extends upwardly and rearwardly therefrom to form an upper support surface 37A
which butts the bottom of the arm 34 in a lower most position thereof allowed
by the
structure.
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A spring arrangement 36 which in this embodiment is defined by two
side by side springs is connected at its upper end to a bracket 36B connected
to the
underside of the arm 34 and at its lower end 36A to a plate 36C adjacent to
and
fixed to the stop member 37 so that the tension springs 36 act to apply a
downward
force on the parallel linkage tending to pull the link 38 downwardly. The
amount of
string force applied is proportional to the amount of extension of the spring
so that it
is proportional to the angle of the upper arm 34 around the pivot pin 34A.
Thus the
spring force increases as the parallel arms pivot upwardly and decreases as
the
parallel arms pivot downwardly.
A packer wheel 40 includes a hub 40A carried on a spindle 40B
supported by a support 40C including a top plate 40D and either one or two
depending legs 40E each on a respective side of a pneumatic tire 40F.
A scraper strap 41 includes a top plate 41A attached to the plate 40D
and includes a scraper portion 41B extending rearwardly and over the wheel
tire 40F
so that a rear end 41C of the strap engages a peripheral surface of the packer
wheel
tire 40F at a position just above the spindle 40b at the rear so that as the
tire moves
upwardly and rearwardly, any mud collecting on the tire periphery is scraped
away
and does not reach the base 40D of the support 40C to cause collection.
The base 40D is connected to a pair of parallel support tubes 42A and
42B of a support arm 42 which extend upwardly and forwardly to the side walls
38A
and 38B respectively of the link 38 so that the support arm 42 is rigidly
connected to
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the link and moves with it by a welded connection between the tubes and the
side
walls of the link.
A trip spring support tube 49 extends rearwardly from a front end 49B
welded between the sides 38A and 38B of the link 38 to a rear end 42A of the
5 support tube which is braced to the plate 40D by a tubular brace 50. This
forms a
triangular braced system which holds the packer wheel at a rigid fixed
position
relative to the link 38 so that the packer wheel can only float upwards and
downwards with the parallel linkage 33.
An opener 51 includes a ground opening element 51A connected to a
10 shank 51B. The ground opening element can be of many different types
such as
points which knock on to or engage on to the shank or other types such as disk
openers. A point 510 is shown and as is well known includes seed and/or
fertilizer
guide tube systems 51D of a conventional construction.
The shank 51B is connected at its upper end to an element 51F
15 formed as a sleeve which connects at its upper end to a forwardly
extending portion
51E located between the side walls 38A and 388 of the link 38. The forward end
51E mounts on the pin 35D for pivotal movement of the element 51F and shank
51D
relative to the link 38 in a tripping action. The forward end 51E carries a
lever 51G
extending upwardly from the pin 35B to an upper end which is attached to a
forward
end of a trip spring 52 locatea within the tube 49. Upward and rearward
tripping
action of the opener 51 by pivotal movement about the pin 35B does not change
the
position of the link 38 or the packer wheel but allows the point to move away
from an
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obstacle while tensioning the spring 52 by pulling forwardly on its front end
relative
to its rear end which is anchored at the end 49A of the tube 49.
Thus the plurality of seeding elements 30 each include a bracket 32
mounted on the tool bar 10A of the frame so that the seeding elements 30 are
arranged at spaced positions across the width of the frame for applying seeds
to the
ground as the frame is moved across the ground.
Each seeding element including the ground opener 51A for cutting a
furrow into the surface of the ground and a packer wheel 40 behind the ground
opener 51A for rolling along the ground at or adjacent to the furrow so formed
in a
packing action.
Each seeding element 30 is mounted on the tool bar for up and down
floating movement relative to the frame independently of the other seeding
elements.
Each seeding element includes the pair of parallel arms 34, 35
connected to the bracket 32 and extending rearwardly therefrom to form a
parallel
linkage 33 for up and down pivotal movement relative to the tool bar to
different
angles of the parallel linkage 33 relative to the ground.
Each seeding element includes a rearwardly extending support arm 42
connected at the link 38 at the rear end of the parallel arms 34, 35 and
carrying the
packer wheel 40 such that the packer wheel can move upwardly and downwardly
relative to the tool bar.
The shank 51B is carried in the sleeve 51F and extends downwardly
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from the sleeve 51F for supporting the cutter or point 51A at a bottom end of
the
shank. The shank 51B is adjustable longitudinally of the sleeve 51F by an
adjustment arrangement 53 which is of a construction which can be quickly and
manually operated. Thus the rectangular sleeve 51F and the rectangular shank
51B
slidable therein each include attached thereto a saw tooth rack 53A and 53B
respectively extending longitudinally thereof. The racks are interengaged at
longitudinally adjustable positions therealong so that the teeth of the racks
hold the
elements at fixed positions defining a fixed position for the point relative
to the pin
35B. A manually operable cam 53C engages the shank 51B on the side opposite
the rack 53A, so as to press the rack 53A on to the rack 53B. The cam 53C is
thus
rotatable about a pin 53E so as to be movable to a locked position of a nose
53D as
shown in which the racks are forced into engagement. The cam can be released
by
a spring handle 53G to a released position where the nose is moved away from
the
shank in which the racks are free for longitudinal adjustment. The spring
handle is a
wire which can be lifted from a latch 53H in the locked position and rotated
to the
release position of the nose.
As shown in Figure 6, a control device in the form of an actuating valve
60 is arranged to raise and lower the tool bar relative to the ground by
operating
hydraulic pressure to the cylinder 15B from the tractor hydraulics 61. This
acts so as
to change height of the tool bar relative to the ground and hence the angle A
of the
parallel linkage relative to the ground so as to change the spring force
generated by
the spring 36.
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In Figure 6 alternative arrangements are shown.
In one arrangement, the control device 60 is operated in response to a
signal from a sensor 60A at the seeding element.
The sensor 60A for example as shown in Figure 1 can be responsive
to the angle of the parallel linkage relative to the tool bar.
In another arrangement, the control device is operated in response to a
signal from a sensor 60C responsive to a height of the ground relative to the
tool bar
detected for example at the rocker shaft 15D.
In another arrangement, the height of the tool bar is controlled by the a
sensor 60D responsive to pressure at the hydraulic cylinder 15B.
In another arrangement, the height of the tool bar is controlled by the a
sensor 60E sensing the actual force applied by the ground on at least one of
the
packer wheels.
