Note: Descriptions are shown in the official language in which they were submitted.
CA 02550141 1999-10-26
DIFFERENTIAL CONNECTING ROD AND
DRAFT CABLE FOR AGRICULTURAL TILLAGE DEVICE
This is a divisional of application serial number 2,287,627 filed October 26,
1999.
Field of the Invention
This invention relates to the improvement of an agricultural ground-working
cultivator.
More specifically it relates to an improvement of the centre frame of a
cultivator and
support for a pair of opposing wings on the said cultivator.
Background of the Invention
The need to till and cultivate soil for the planting of crops has been
accomplished since
the earliest days of civilisation. More recently, tillage devices have
increased in
complexity and size, depending on the type of crops, quantity and soil being
tilled. There
has also been an increased emphasis on conserving natural resources resulting
in these
concerns being integrated in modern tillage systems. These concerns have
resulted in
larger and more complex tillage systems that assist in achieving these goals.
A larger
tillage system allows a single operator to perform tillage operations on a
greater area.
More sophisticated tillage systems further allow for the accomplishment of low
till and no
till farming techniques. Low till and no till farming encourages tilling,
planting and
fertilising in a single pass of the tillage device or cultivator through the
field. By only
disturbing the soil a single time, there is less soil compaction, less
moisture loss, less
pesticides and herbicides needed and less fertiliser required. However, these
larger and
more complex tillage systems create complexities that were previously unknown
in the
art.
Previously, an agricultural tractor could pull a relatively small tillage
device or cultivator.
As the tillage device or cultivator moved over hills and similar undulations
in the terrain
all the ground-working implements maintained contact with the soil. The width
of the
tillage device was sufficiently small for it generally not to have problems
maintaining
ground contact. However, as the tillage devices were increased in width, so as
to be able
to till a greater area in a single pass, the undulations in the ground
resulted in the ground-
working tools failing always to contact the earth.
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Furthermore, to transport the tillage device or cultivator for the farming
operations it was
necessary for the device to be capable of being collapsed to a width
sufficient to be
moved. To accomplish these goals, a centre section with. a set of pivotable
wings was
designed. The wings could pivot horizontally relative to the centre section
allowing the
tillage device to accommodate some undulations in the ground. The wings could
also be
folded into the centre section allowing for easy transport before and after
farming
operations. Eventually, an outer set of wings was added increasing the width
of the tillage
device.
Figure 1 illustrates the general configuration of a tillage device or
cultivator. Specifically,
there is a centre section directly behind the tractor. There is a set of inner
wings and outer
wings respectively surrounding the centre section. Some cultivators are folded
into the
transport position along an axis along the direction of travel; other
cultivators are folded
along a diagonal axis.
In prior art cultivators, the wings can rotate on an axis in the direction of
travel, the wings
generally cannot rotate, flex or bend on an axis perpendicular to travel.
Finally, the
additional inner wings and outer wings create large additional draft forces on
the frame of
the cultivator, draft forces being those created when the ground-working tool
is pulled
through the soil.
These are complex problems to overcome, especially when considering the need
for the
tillage device to be a collapsed from its field operation mode to the compact
transportation mode.
Consequently, the need exists for a linkage, which allows for the inner wings
to move
transversely to the centre section of a tillage device. The need also exists
for a means to
help distribute the draft load generated by the outer wings.
Summary of the Invention
The present invention relates to an agricultural cultivator having a central
section flanked
by wings which are connected to the centre section in such a manner that in
addition to
being able to pivot relative the centre section about an axis parallel to the
direction of
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travel of the cultivator may pivot relative to the centre section about a
horizontal axis
transverse to the direction of travel of the cultivator.
The invention provides an agricultural cultivator coniprising: a. a hitch
frame and a
drawbar frame including a drawbar center frame and a drawbar wing frame; b.
said
drawbar center frame pivotally attached to the hitch frame on a transverse
axis for
rotation between a downward working position and an upward transport position;
and
c. said drawbar wing frame being attached to a side of the drawbar center
frame by a
multi-joint assembly whereby: i. the multi-joint assembly is attached to the
drawbar
center frame defining a first axis perpendicular to the drawbar center frame;
ii. the multi-
joint assembly is attached to the drawbar wing frame defining a second axis
perpendicular
to the first axis and perpendicular to the drawbar wing frame; and iii. the
multi-joint
assembly includes a third axis generally longitudinal to the drawbar wing
frame.
In a preferred embodiment a folding draft support wire acts as a means by
which the draft
force on the outer wings is transferred to the centre hitch frame. The wire is
pivotally
attached to the outer wing and wing hitch frame. Supporting the wire is a
folding support
arm. The arm has an outer arm pivotally attached to an inner arm. The inner
arm is
attached to the wing hitch frame. Controlling the outer arm is a chain that is
attached to
the wing hitch frame by a chain arm. The chain is also attached to an
elongated plate on
the outer arm. This design allows the support arm to be folded when the
cultivator is in
the transportation mode.
The disclosure also describes connecting rods and draft cables as hereinafter
set forth.
Brief Description of the Drawings
The invention will now be described further, by way of example, with reference
to the
accompanying drawings, in which:
Figure 1 is an overhead schematic view of an agricultural cultivator,
Figure 2 is a side, overhead view of the differential connecting rod in the
field mode,
Figure 3 is a side, overhead view of the differential connecting rod in the
transport mode,
Figure 4A is a side view of the cultivator in the headland mode,
Figure 4B is a rear view of the cultivator in the field mode,
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Figure 4C is a rear view of the cultivator in the transportation mode,
Figure 4D is a side, front view of the transport assembly,
Figure 4E is a side, front view of the differential rod while the cultivator
is in field
operating mode,
Figure 4F is a view of the folding support wire when the cultivator is in the
transportation
mode,
Figure 5 is a front view of the differential connecting rod, showing both
spring
assemblies, and
Figure 6 is a front view of the left side of the differential connecting rod
showing a single
spring assembly.
Detailed Description of the Preferred Embodiments
Referring to the drawings, it is possible to observe the major elements and
general
operation of the present invention. The terms "left" and "right" are used as a
matter of
convenience and are determined by standing at the rear of the tillage device
or cultivator
and facing the forward end in the normal direction of travel when the tillage
device or
cultivator is operating in the field (field mode, see figure 4B). Likewise,
forward and
rearward are determined by normal direction of travel in the field mode of the
tillage
device or cultivator. Upward or downward orientations are relative to the
ground or
operating surface. Horizontal or vertical planes are also relative to ground.
Figure 1 illustrates a general overhead view of a pull-type tillage device or
cultivator. A
conventional tillage device or cultivator consists of a centre section 2 with
two inner
wings 3 positioned next to the centre section 2. Next to the inner wings 3 are
two outer
wings 4. The tillage device or cultivator 1 has a triangular shaped centre
frame hitch 9.
The base of this hitch 9 is attached to the centre section 2 and the front of
the hitch 9 is
attached to a tractor mount 8. The tractor mount 8 is attached to a
conventional
agricultural tractor. The tractor pulls the tillage device or cultivator 2 and
also supplies
hydraulic power or mechanical power via the power-take-off (PTO) to the
various
implements on the cultivator 2.
Supplementing the centre frame hitch 9 is the wing hitch frame 10 that
provides draft
support to the inner wings 3. Supporting the entire cultivator 2 are a series
of castor
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wheels 5 located towards the front of the cultivator 2 and a series of packing
or rear
supporting wheels 7 located towards the rear of the cultivator 2.
The centre section 2 has a centre frame 22 and a toolbar 6 which supports
various ground-
working implements. Such implements are well known in the art and include
ploughs,
coulters, discs as well as other implements. Each inner wing 3 and outer wing
4 also
possesses a tool bar 6. The inner wing 3 also has an inner wing frame 13. The
centre
frame 22 and inner wing frame 13 are connected by means of a universal joint
assembly
21 that can best be seen in figures 2 and 3.
Figure 1 shows the cultivator 2 in the field mode. In the field mode, the
inner and outer
wings 3 and 4 are fully extended horizontally across the field. There is also
a headland
mode (see figure 4A) where the wings (2 and 3) are still extended, but the
tool bars 6 are
raised out of the soil. The headland mode is used at the end of a crop row
when an
operator wishes to turn the tractor and cultivator 2 around and partially
raise the ground
working implements. The transportation mode (see figure 4C) involves rotating
the centre
frame 22 and inner wing frame 13 upwards through 900 This raises the toolbars
6 and
packing wheels 6 up into the air. The wings 3 and 4 are then rotated
rearwards. This
results in a cultivator that is narrow and may be transported to another
field.
The draft support wire 50 can best be seen in figure 1 and extends from the
wing hitch
frame 10 to the outer wing 4. During field operations, this wire can transfer
some of the
draft force in the outer wing 4 to the centre hitch frame 9.
As seen in figures 2 and 3, the differential connecting rod 20 is located
parallel to the
centre frame 22. It controls the movement of the universal joint assembly 21.
There are
two, identical connecting rods 20 which control respective universal joint
assemblies 21
located on the left and right sides of the centre frame 22. For purposes of
brevity, only the
right side is illustrated and discussed. However, the left side works in an
analogous
fashion.
The universal joint assembly consists of a universal joint 25 with a centre
frame attach 27
and a wing attach 26. Generally speaking, the centre frame 22 is connected to
the centre
frame attach 27 and the wing frame is connected to the wing attach 26. Figure
2 shows
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the centre frame 22 and universal joint assembly 21 oriented in the field
mode. Figure 3
illustrates the centre frame 22 and universal joint assembly 21 rotated
forward 90 into the
transportation mode.
Connecting the universal joint assembly 21 to the centre frame 22 is bracket
23 with a slot
24. At the other end of the universal joint 25 there is a conventional
spherical bearing 28
which allows for a full range of motion and permits the universal joint 25 to
move in the
slot 24. This allows the wing section a full range of motion about the
universal joint.
In the prior art, the wing section could only rotate about an axis parallel to
the direction of
travel. By contrast, in the present invention, the wing section can rotate
upwards or
downwards on an axis perpendicular to the direction of travel and about a
vertical axis.
However, to control the movement of the universal joint 25 within the slot 24,
there is the
differential connecting rod 20.
The universal joint assembly 21 has three axes of motion. The three-axes joint
consists of
a universal joint with one joint pin connected to a yoke on the centre frame
22 at bearing
28 at one end and constrained in the slot 24 at the other end, defining a
first axis
longitudinal to the pin and a second axis perpendicular to the pin through the
bearing 28.
The pin 28 is allowed freedom to rotate about the second axis within the
limits of the slot
24 of the bracket 23. The second axis is therefor generally transverse. A
third axis is
defined by the joint pin connected to a yoke on the wing frame, which is
perpendicular to
the first axis and is a pivot for inner wings 3 to follow ground elevations
when in
transport.
The first axis in the transport position allows rear folding of the wing
frames and in the
field position is a pivot allowing wings to follow ground elevations as shown
in figure 2.
The first axis allows rear folding of the wing frames. The second axis allows
the drawbar
to rotate relative to the centre section so that the attached gangs are on
average, aligned
with the pitch of the ground (rising or falling slope in the direction of
travel). The range
of the second axis rotation is limited by the ends of the slot 24.
In figure 2, the differential connecting rod 20 is attached towards the centre
of the centre
frame 22 by means of the spring assembly 40. The spring assembly 40 will be
described
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CA 02550141 1999-10-26
in greater detail below. At the end of the centre frame 22, the connecting rod
is pivotally
attached to an 'L'-shaped linkage 30. The 'L'-shaped linkage is pivotally
attached to the
centre frame 22 at the linkage pivot 31. The end of the 'L'-shaped linkage 30
is attached
to the universal joint assembly 21 at the pivot 29.
Turning to figures 5 and 6, it is possible to observe both spring assemblies
40. As
previously indicated both spring assemblies 40 are identical in construction
and operation.
Figure 6 illustrates a single spring assembly 40 viewed overhead. Each spring
assembly
40 consists of a co-axial spring 41 held in a slightly compressed positioned
by a pair of
threaded tie rods 42. The differential connecting rod 20 is in two parts that,
in field
operation abut each other at the centre of the centre frame section. Each part
of the
connecting rod 20 is slidably supported by a inner stop block 46 which is
attached to the
frame 22. The differential connecting rod 20 is biased to a central position
as shown by
the spring assembly 40.
The spring assembly 40 is attached at one end to the inner stop block 46 by
tie rods 42.
The spring is co-axial with the differential connecting rod 20. It is
constrained between
two abutment inner sliding blocks 44a and 44b. Inner sliding block 44a is
constrained by
nuts 45 at the end of tie rods 42. A pair of outer sliding blocks 43a are
attached to the
differential connecting rod 20 (secured by bolt shown) and are in abutment
with an inner
sliding block 44a. Another pair of outer sliding blocks 43b are welded to the
differential
tie rod 20 and are in abutment with inner sliding block 44b, passing through
the inner stop
block 46.
In operation, when a wing rotates about the second axis in direction 66a,
driven to an
average position between the attached gangs as the ground slope varies, then
it drives the
L-shape lever and then the connecting rod 20 in direction 66. The spring is
compressed
between the outer sliding blocks 43a and the inner stop block 46, between
which are also
pressed inner sliding block 44a and 44b. The motion is directed onto the other
abutting
connecting rod and causes the opposite wing to rotate about its second axis in
an equal
amount in the opposite direction. Therefor the centre section is suspended at
an average
height between the two adjacent wing sections.
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When being driven from the other wing section, the connecting rod 20 is forced
in the
other direction 67. Outer sliding blocks 44b abut onto the inner sliding block
43b. The
spring shown in figure 6 is then compressed between the outer sliding blocks
43b and
nuts 45, between which again pressed the inner sliding blocks 44b and 44a are
again
pressed. The spring works in both directions to bias the half of the
connecting rod
assembly to a central position. The other half works the same way. The height
of centre
section is driven by the three axes joints attaching the wing frames on either
side. The
differential connecting rod assembly keeps it at an average position between
the two wing
frames and biases the wing frames into rotational alignment with the centre
frame about
the second axis. It also distributes weight transfer force that may be
optionally applied to
the centre frame onto each of the wing frames. It should be noted that there
are several
possible secondary embodiments involving the connecting rods.
When the cultivator 2 is in the transportation mode, as seen in figure 3, it
is important the
pivot 29 be fixed in the slot 24. Because the wing section's weight is
supported partially
by the universal assembly 21, it is important that the pivot 29 should not
impact the slot
24. To achieve that goal, a transport assembly 47 has been included to prevent
translation
of the differential rod. The transport assembly 47 has a tongue 48 attached to
the centre
frame 22. A tongue spring 49 is biased between the differential connecting
rods 20 as
seen in figure 3. During the transition from the field mode (as seen in figure
2) to the
transportation mode (as seen in figure 3), the wings are folded upwards 90
and the ends
of the wings are folded rearwards. This places a force similar to 67a on the
pivot 29.
These forces pull both differential connecting rods 20 away from the centre of
the centre
frame 22. The spring-biased tongue 49 is inserted between the rods when the
centre frame
22 is rotated forward 90 . This locks the rods and holds the pivot 29 at one
end of the slot
24 during transport (as seen in figure 4D). Conversely, the tongue 48 is
removed from the
between the rods when the centre frame 22 is rotated into the field position.
The folding draft support wire 50 can be seen in figures 1 and 4F. The wire 50
is attached
to the cultivator 2 at three points. The wire 50 is pivotally attached to the
inner hitch 52.
At the opposite end, the wire 50 is pivotally attached to the outer wing hitch
51 (see
figure 4F). Supporting the wire 50 in the middle is the folding support arm
53. The
folding draft support wire 50 is designed to transfer the draft force created
by the outer
wings to the centre hitch frame. Failure to transfer the draft force could
result in the outer
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wings twisting behind the centre section. As seen in figure 4F, the support
wire 50 is
lifted towards the centre frame and wing sections during the transportation
mode. The
folding support arm 53 accomplishes this. The folding support arm 53 consists
of an inner
arm 54 attached to the wing hitch frame 10. A hinge 56 pivotally attaches the
outer arm
55. To ensure that the support arm 53 remains fully extended during the field
mode, the
outer arm 55 has an elongated plate 55a. Attached to the elongated plate 53a
is a chain 57.
The chain is connected to the wing hitch frame 10 by a pivotally mounted chain
arm 58.
The support wire 50 is attached to the top of the outer arm 55.
During the field mode, the wing hitch frame 10 is rotated 90 downwards. The
chain arm
58 pulls the elongated plate 55a and outer arm 55 away and downwards. This
extends the
draft wire 50. Conversely, when converting the cultivator from the field mode
to the
transport mode, the wing hitch frame 10 rotates upwards 90 . This allows the
outer arm to
pivot about the hinge 56. The wire is moved towards the hitch frame as seen in
figure 4F.
It is the tension in the wire as the wing frames are folded rearwardly that
causes the wire
to be pulled in close to the frame in the transport position. The outer arm 55
guides the
position of the wire up and over the wheel 5 so that it does not rub on the
wheel or the
ground in transport.
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