U.S. patent application number 13/842642 was filed with the patent office on 2013-08-22 for row unit for agricultural implement.
This patent application is currently assigned to Dawn Equipment Company. The applicant listed for this patent is Dawn Equipment Company. Invention is credited to Joseph D. Bassett.
Application Number | 20130213676 13/842642 |
Document ID | / |
Family ID | 45805387 |
Filed Date | 2013-08-22 |
United States Patent
Application |
20130213676 |
Kind Code |
A1 |
Bassett; Joseph D. |
August 22, 2013 |
Row Unit For Agricultural Implement
Abstract
An agricultural row unit for use with a towing frame hitched to
a tractor includes an attachment frame adapted to be rigidly
connected to the towing frame, a linkage pivotably coupled to the
attachment frame, and a row unit frame having a leading end
pivotably coupled to the linkage to permit vertical pivoting
movement of the row unit frame relative to the attachment frame. A
hydraulic cylinder coupled to the attachment frame and the linkage,
for urging the row unit frame downwardly toward the soil, includes
a movable ram extending into the cylinder, and a hydraulic-fluid
cavity within the cylinder for receiving pressurized hydraulic
fluid for advancing the ram in a direction that pivots the linkage
and the row unit frame downwardly toward the soil. An accumulator
positioned adjacent to the hydraulic cylinder has a fluid chamber
containing a diaphragm, with the portion of the chamber on one side
of the diaphragm being connected to the hydraulic-fluid cavity in
the hydraulic cylinder, and the portion of the chamber on the other
side of the diaphragm containing a pressurized gas.
Inventors: |
Bassett; Joseph D.;
(Sycamore, IL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dawn Equipment Company; |
|
|
US |
|
|
Assignee: |
Dawn Equipment Company
Sycamore
IL
|
Family ID: |
45805387 |
Appl. No.: |
13/842642 |
Filed: |
March 15, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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12882627 |
Sep 15, 2010 |
|
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13842642 |
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Current U.S.
Class: |
172/260.5 |
Current CPC
Class: |
A01B 63/24 20130101;
A01C 7/205 20130101; A01B 33/024 20130101; Y10S 111/927 20130101;
A01B 63/111 20130101; A01B 63/32 20130101; A01B 61/046 20130101;
A01B 61/044 20130101; A01B 63/008 20130101 |
Class at
Publication: |
172/260.5 |
International
Class: |
A01B 61/04 20060101
A01B061/04; A01B 63/32 20060101 A01B063/32 |
Claims
1-20. (canceled)
21. An agricultural system, comprising: a plurality of row units
adapted to be coupled to a single tractor; a fluid supply for
supplying the plurality of row units with pressurized fluid; a
plurality of control valves coupled, respectively, to the plurality
of row units, each control valve of the plurality of control valves
receiving pressurized fluid from the fluid supply; and a control
system coupled to and controllably adjusting each control valve
such that down pressure is adjustable on at least a portion of a
respective row unit.
22. The agricultural system of claim 21, further comprising a
plurality of feed lines coupling the fluid supply and the plurality
of row units, each one of the plurality of control valves being
coupled on a separate feed lines of the plurality of feed
lines.
23. The agricultural system of claim 21, wherein the fluid supply
includes a supply manifold for supplying the pressurized fluid to
the plurality of row units.
24. The agricultural system of claim 21, further comprising a
return manifold for receiving return fluid from the plurality of
control valves.
25. The agricultural system of claim 21, wherein the controllably
adjusting of each control valve includes turning off the supplying
of pressurized fluid to at least one of the plurality of control
valves but not to all of the plurality of control valves.
26. The agricultural system of claim 21, wherein each of the
plurality of row units includes: an attachment frame adapted to be
rigidly connected to a towing frame hitched to the single tractor;
a linkage pivotably coupled to the attachment frame; a row unit
frame having a leading end pivotably coupled to the linkage to
permit vertical pivoting movement of the row unit frame relative to
the attachment frame; at least a furrow-forming device mounted on
the row unit frame; a hydraulic cylinder coupled to the attachment
frame and the linkage for urging the row unit frame downwardly
toward the soil, the hydraulic cylinder including a movable ram
extending into the cylinder, and a hydraulic-fluid cavity within
the cylinder for receiving pressurized hydraulic fluid for
advancing the ram in a direction that pivots the linkage and the
row unit frame downwardly toward the soil, and an accumulator
positioned adjacent to the hydraulic cylinder and having a fluid
chamber containing a diaphragm, the portion of the chamber on one
side of the diaphragm being connected to the hydraulic-fluid cavity
in the hydraulic cylinder, and the portion of the chamber on the
other side of the diaphragm containing a pressurized gas.
27. The agricultural system of claim 26, wherein a single unitary
housing forms the hydraulic cylinder and a cavity containing the
accumulator.
28. The agricultural system of claim 27, wherein the single unitary
housing forms a fluid passageway connecting the hydraulic cylinder
and the accumulator.
29. The agricultural system of claim 26, wherein the hydraulic
cylinder is connected to the attachment frame, and the ram is
connected to the linkage.
30. An agricultural system for use with a towing frame hitched to a
tractor, the system comprising: a fluid supply for supplying
pressurized fluid; and a plurality of row units adapted to be
coupled to a single tractor, each row unit of the plurality of row
units including an attachment frame adapted to be rigidly connected
to the towing frame, a linkage pivotably coupled to the attachment
frame, a row unit frame having a leading end pivotably coupled to
the linkage to permit vertical pivoting movement of the row unit
frame relative to the attachment frame, at least a furrow-forming
device mounted on the row unit frame, a hydraulic cylinder coupled
to the attachment frame and the linkage for applying down pressure
to the row unit frame, and a control valve coupled to the fluid
supply, the control valve being individually controllable to adjust
the down pressure applied by the hydraulic cylinder.
31. The agricultural system of claim 30, further comprising a
plurality of feed lines coupling the fluid supply and the plurality
of row units, each one of the plurality of control valves being
coupled on a separate feed lines of the plurality of feed
lines.
32. The agricultural system of claim 30, wherein the fluid supply
includes a supply manifold for supplying the pressurized fluid to
the plurality of row units.
33. The agricultural system of claim 30, further comprising a
return manifold for receiving return fluid from the plurality of
control valves.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to agricultural implements
and, more particularly, to an agricultural row unit for use with
agricultural implements such as planting row units.
BACKGROUND OF THE INVENTION
[0002] As an agricultural planter row unit travels across fields
with variable soil types, soil moisture, residue levels and
topography, it is difficult to maintain constant seed depth and
other parameters due to changing conditions which would ideally
require varying the row unit down force pressure. For example,
farming with higher residue levels also requires higher row unit
down force levels as row cleaners, coulters and other attachments
require applied force to keep them in the ground and at consistent
depths.
[0003] At the same time, in many locations there are immoveable
rocks or other obstructions at or below the soil surface which
require the planter row unit to be able to quickly and freely
(without undue increase in the row unit down force) rise up and
over the obstruction freely and then quickly move back down,
leaving a minimum amount of the row unplanted. All this must be
accomplished at ground speeds of 6 mph or more. Today's planters
typically include many individual row units, at times up to 120 ft
wide, each of which may be encountering rocks etc. or have a need
to float up or down independently.
[0004] Traditionally springs have been used to urge row units
downward. Recently air bag systems have been used to overcome some
of the drawbacks to air spring systems. Air systems provide a more
uniform down force through the vertical range of travel, compared
to springs, and are somewhat easier to adjust than springs. However
due to the compressibility of air and the relatively large volumes
required, changes in air pressure are very cumbersome and not
adaptable to very fast change and response to in-cab controls on
the go. Air bag systems typically have a very large cross-sectional
area in relation to the hose feeding the air spring with pressure,
which can provide a large multiplication of force and allow for
relatively good isolation of one row unit relative to another.
However, air bag systems typically do not allow for rapid change of
the force being applied, because of the large volume of the air
spring in relation to the cross section of the hose supplying the
air.
[0005] Prior attempts to use devices such as combination
spring/hydraulic shock absorbers do not provide ready adjustment on
the go and tend to increase in force when rapidly striking a
foreign object such as a rock requiring the row unit to quickly
rise and come back down to resume planting. This increase in force
levels can cause damage to the planter row unit components.
[0006] Some previous down-force systems use a spring and a
hydraulic cylinder in series. In these systems the hydraulic
cylinder does not directly control row unit down force, but rather
is used to vary the amount of spring pressure applied to each
unit.
[0007] Other systems use hydraulics with a central accumulator.
However, with the accumulator separated from the force creating
cylinder, pressure spikes can develop when hitting obstructions
such as a rock at high speed since oil must be forced through hoses
or tubes to the remotely located accumulator. This is especially
problematic on planters having 50 or more row units.
[0008] As computers and GPS systems have allowed crop production to
be managed in a location-specific way as an implement moves through
the field, it has become necessary to achieve more rapid changes in
the setting or adjustment of the implement. In the case of a
planter row unit, it is also necessary to generate a large amount
of force. Each individual planter row unit must be able to react to
the soil it encounters independently of the other row units.
[0009] An air spring can allow for remote adjustment of the planter
down pressure without stopping the forward motion of the implement,
which is inefficient. Mechanical springs have historically required
that the operator stop the implement, get out of the tractor, and
make a manual adjustment. The slow rate at which an air spring
system can be inflated or deflated means that even if a GPS system
determines that a change needs to be made because of a programmed
or sensed change in the local soil composition or conditions, by
the time the pump can change the air pressure the implement has
already moved too far forward of where the change needed to be
made. This forces the average grid size in which active adjustments
of the planter down pressure can be made to be quite large.
SUMMARY OF THE INVENTION
[0010] In one embodiment, an agricultural row unit for use with a
towing frame hitched to a tractor includes an attachment frame
adapted to be rigidly connected to the towing frame, a linkage
pivotably coupled to the attachment frame, and a row unit frame
having a leading end pivotably coupled to the linkage to permit
vertical pivoting movement of the row unit frame relative to the
attachment frame. At least a furrow-forming device is mounted on
the row unit frame. A hydraulic cylinder coupled to the attachment
frame and the linkage, for urging the row unit frame downwardly
toward the soil, includes a movable ram extending into the
cylinder, and a hydraulic-fluid cavity within the cylinder for
receiving pressurized hydraulic fluid for advancing the ram in a
direction that pivots the linkage and the row unit frame downwardly
toward the soil. An accumulator positioned adjacent to the
hydraulic cylinder has a fluid chamber containing a diaphragm, with
the portion of the chamber on one side of the diaphragm being
connected to the hydraulic-fluid cavity in the hydraulic cylinder,
and the portion of the chamber on the other side of the diaphragm
containing a pressurized gas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The invention may best be understood by reference to the
following description taken in conjunction with the accompanying
drawings, in which:
[0012] FIG. 1 is a perspective view of a planting row unit attached
to a towing frame.
[0013] FIG. 2 is a partially sectioned side elevation of the
planting row unit of FIG. 1 with the linkage that connects the row
unit to the towing frame in a level position.
[0014] FIG. 3 is the same side elevation shown in FIG. 1 but with
the linkage tilted upwardly to move the row unit to a raised
position.
[0015] FIG. 4 is the same side elevation shown in FIG. 1 but with
the linkage tilted downwardly to move the row unit to a lowered
position.
[0016] FIG. 5 is a top plan view of the hydraulic cylinder and
accumulator unit included in the row unit of FIGS. 1-4.
[0017] FIG. 6 is a vertical section taken along line 11-11 in FIG.
10.
[0018] FIG. 7 is a side elevation of the unit shown in FIGS. 5 and
6 connected to a pair of supporting elements, with the support
structures and the connecting portions of the hydraulic cylinder
shown in section.
[0019] FIGS. 8A and 8B are enlarged cross sectional views of the
supporting structures shown in section in FIG. 7.
[0020] FIG. 9 is an enlarged perspective of the right-hand end
portion of FIG. 1 with a portion of the four-bar linkage broken
away to reveal the mounting of the hydraulic cylinder/accumulator
unit.
[0021] FIG. 10 is a schematic diagram of a first hydraulic control
system for use with the row unit of FIGS. 1-9.
[0022] FIG. 11 is a schematic diagram of a second hydraulic control
system for use with the row unit of FIGS. 1-9.
[0023] FIG. 12 is a diagram illustrating one application of the
hydraulic control system of FIG. 11.
DETAILED DESCRIPTION OF ILLUSTRATED EMBODIMENTS
[0024] Although the invention will be described in connection with
certain preferred embodiments, it will be understood that the
invention is not limited to those particular embodiments. On the
contrary, the invention is intended to cover all alternatives,
modifications, and equivalent arrangements as may be included
within the spirit and scope of the invention as defined by the
appended claims.
[0025] Turning now to the drawings, a planting row unit 10 includes
a furrow-opening device for the purpose of planting seed or
injecting fertilizer into the soil. In the illustrated embodiment,
the furrow-opening device is a V-opener 11 formed by a pair of
conventional tilted discs depending from the leading end of a row
unit frame 12. It will be understood that other furrow-opening
devices may be used. A conventional elongated hollow towing frame
13 (typically hitched to a tractor by a draw bar) is rigidly
attached to the front frame 14 of a conventional four-bar linkage
assembly 15 that is part of the row unit 10. The four-bar
(sometimes referred to as "parallel-bar") linkage assembly 15 is a
conventional and well known linkage used in agricultural implements
to permit the raising and lowering of tools attached thereto.
[0026] As the planting row unit 10 is advanced by the tractor, the
V-opener 11 penetrates the soil to form a furrow or seed slot.
Other portions of the row unit 10 then deposit seed in the seed
slot and fertilizer adjacent to the seed slot, and close the seed
slot by distributing loosened soil into the seed slot with a pair
of closing wheels 16. A gauge wheel 17 determines the planting
depth for the seed and the height of introduction of fertilizer,
etc. Bins 18a and 18b on the row unit carry the chemicals and seed
which are directed into the soil. The planting row unit 10 is urged
downwardly against the soil by its own weight, and, in addition, a
hydraulic cylinder 19 is coupled between the front frame 14 and the
linkage assembly 15 to urge the row unit 11 downwardly with a
controllable force that can be adjusted for different soil
conditions. The hydraulic cylinder 19 may also be used to lift the
row unit off the ground for transport by a heavier, stronger,
fixed-height frame that is also used to transport large quantities
of fertilizer for application via multiple row units.
[0027] The hydraulic cylinder 19 is shown in more detail in FIGS. 5
and 6. Pressurized hydraulic fluid from the tractor is supplied by
a hose 20 to a port 21 that leads into a matching port 22 of a
housing 23 that forms a cavity 24 of a hydraulic cylinder
containing a ram 25. The housing 23 also forms a side port 26a that
leads into cavity 26b that contains a gas-charged hydraulic
accumulator 27. The lower end of the cavity 24 is formed by the top
end surface of the ram 25, so that the hydraulic pressure exerted
by the hydraulic fluid on the end surface of the ram 25 urges the
ram downwardly (as viewed in FIG. 6), with a force determined by
the pressure of the hydraulic fluid and the area of the exposed end
surface of the ram 25. The hydraulic fluid thus urges the ram 25 in
an advancing direction (see FIG. 4).
[0028] As can be seen most clearly in FIG. 6, the hydraulic
cylinder 19 and the accumulator 27 are mounted as a single unit on
the front frame 14, with the lower end of the ram 25 connected to a
cross bar 30 that is joined at one end to a vertical link 31. The
upper and lower ends of the link 31 are pivotably attached to upper
and lower links 15a and 15b, respectively, on one side of the
four-bar linkage 15. The other end of the cross bar 30 is angled
upwardly and pivotably attached to the upper link 15c on the
opposite side of the four-bar linkage 15. With this mounting
arrangement, retracting movement of the ram 25 into the cavity 24
tilts the linkage assembly 15 downwardly, as depicted in FIG. 3,
thereby lowering the row unit. Conversely, advancing movement of
the ram 25 tilts the linkage assembly 15 upwardly, as depicted in
FIG. 4, thereby raising the row unit.
[0029] The accumulator 27 includes a diaphragm 28 that divides the
interior of the accumulator into a hydraulic-fluid chamber 29a and
a gas-filled chamber 29b, e.g., filled with pressurized nitrogen.
FIG. 2 shows the ram 25 in a position where the diaphragm 28 is not
deflected in either direction, indicating that the pressures
exerted on opposite sides of the diaphragm are substantially equal.
In FIG. 3, the ram 25 has been retracted by upward movement of the
row unit, and the diaphragm 28 is deflected downwardly by the
hydraulic fluid forced into the accumulator 27 by the retracting
movement of the ram 25. In FIG. 4, the ram 25 has been moved to its
most advanced position, and the diaphragm 28 is deflected upwardly
by the air pressure as hydraulic fluid flows from the accumulator
into the cavity 24. The use of this compact hydraulic down-force
unit with an integral accumulator on each row unit provides the
advantages of quick response and remote adjustability of a
hydraulic down-force control system. If an obstruction requires
quick movement, oil can flow quickly and freely between the force
cylinder and the adjacent accumulator.
[0030] As can be seen in FIG. 4, advancing movement of the ram 25
is limited by engagement of stops 40, on the lower links of the
four-bar linkage 15, with the row unit frame 12. This prevents any
further advancement of the ram 25. Advancing movement of the ram 25
expands the size of the cavity 24 (see FIG. 4), which causes the
diaphragm 28 in the accumulator 27 to deflect to the position
illustrated in FIG. 4 and reduce the amount of hydraulic fluid in
the accumulator 27. When the ram 25 is in this advanced position,
the row unit is in its lowermost position.
[0031] In FIG. 3, the ram 25 has been withdrawn to its most
retracted position, which can occur when the row unit encounters a
rock or other obstruction, for example. When the ram 25 is in this
retracted position, the row unit is in its uppermost position. As
can be seen in FIG. 3, retracting movement of the ram 25 is limited
by engagement of stops 41, on the lower links of the four-bar
linkage 15, with the row unit frame 12.
[0032] Retracting movement of the ram 25 reduces the volume of the
cavity 24 (see FIG. 3), which causes a portion of the fixed volume
of hydraulic fluid in the cylinder 19 to flow into the chamber 29a
of the accumulator 27, causing the diaphragm 28 to deflect to the
position illustrated in FIG. 3. This deflection of the diaphragm 28
into the chamber 29b compresses the gas in that chamber. To enter
the chamber 29a, the hydraulic fluid must flow through a port 32 in
the top of the accumulator 27, which limits the rate at which the
hydraulic fluid flows into the accumulator. This controlled rate of
flow of the hydraulic fluid has a damping effect on the rate at
which the ram 25 retracts or advances, thereby avoiding sudden
large movements of the moving parts of the row unit, including the
V-opener 11.
[0033] When the external obstruction causing the row unit 10 to
rise is cleared, the combined effects of the pressurized gas in the
accumulator 27 on the diaphragm 28 and the pressure of the
hydraulic fluid return the ram 25 to a lower position. This
downward force on the V-opener 11 holds it in the soil and prevents
uncontrolled bouncing of the V-opener 11 over irregular terrain.
The downward force applied to the V-opener 11 can be adjusted by
changing the pressure of the hydraulic fluid supplied to the
cylinder 19.
[0034] As can be seen in FIGS. 5 and 6, the single unitary housing
23 forms both the cavity 26b that contains the accumulator 27 and
the cavity 24 of the hydraulic cylinder 19 and the fluid passageway
24 that connects the cavity 24 of the hydraulic cylinder 19 to the
cavity 27 of the accumulator. By integrating the hydraulic cylinder
19 and the accumulator 27 in a single housing, there is no relative
motion possible between the cylinder 19 and the accumulator 27,
with minimal possibility for fluid passageways to act like
orifices. The cylinder 19 and the accumulator 27 remain in fixed
positions relative to each other regardless of the movements of the
planter row unit via the linkage assembly 15. In this way the
upward motion of the ram 25 that occurs when the planter row unit
rolls over an obstruction is directly converted into compression of
the gas in the accumulator 27 without restriction. It also allows
the accumulator 27, which is by definition an energy storage
device, to be mounted in a fully enclosed and safe housing. The
accumulator 27 can be securely mounted to avoid puncture or rapid
discharge (if it comes loose), or damage from hitting another part
of the implement or a foreign object. The integrated cylinder and
accumulator is also a convenient single package for installation
and replacement and minimizes the number of hydraulic hoses and
adapters (potential leakage points).
[0035] FIGS. 7, 8A and 8B illustrate in more detail how the
illustrative hydraulic cylinder/accumulator unit is attached to the
front frame 14 and the linkage assembly 15. The top of the unitary
housing 23 forms a stem 41 that projects upwardly through a hole 51
in a bracket 50 attached to the front frame 14. The outer surface
of the stem 41 is threaded to receive a nut 52 that connects the
housing 23 to the bracket 50. The hole 51 is oversized and a rubber
washer 52a is installed on the stem 41 between the nut 52 and the
bracket 50 to allow a limited amount of tilting movement of the
housing relative to the bracket 50. At the base of the stem 41,
beneath the bracket 50, the housing 23 forms a shoulder 42 that
engages a conical bearing ring 53 that also engages a mating lower
surface of a washer 54. Thus, the housing 23 can be tilted relative
to the axis of the hole 51, with the shoulder 42 sliding over the
lower surface of the bearing ring 53.
[0036] A similar arrangement is provided at the lower end of the
ram 25, where a stem 60 extends downwardly through a hole 61 in the
cross bar 30 that is pivotably attached to the linkage assembly 15.
A nut 62 is threaded onto the stem 60 to connect the ram to the
cross bar 30. The hole 61 is oversized and a rubber washer 62a is
installed on the stem 60 between the nut 62 and the cross bar 30 to
allow a limited amount of tilting movement of the ram 25 relative
to the cross bar 30. Above the cross bar 30, a flange 63 on the ram
25 forms a curved conical surface 64 that engages a mating surface
of a curved conical bearing ring 65 that also engages a mating
upper surface of a washer 66. Thus, the ram 25 can be tilted
relative to the axis of the hole 61, with the flange 63 sliding
over the upper surface of the bearing ring 65.
[0037] The use of a hydraulic system permits on-the-go adjustments
to be made very rapidly because the hydraulic fluid is
incompressible and therefore acts more directly than an air system.
In addition, hydraulic fluids typically operate at higher
pressures, which allows greater changes in applied forces. The
accumulator 27 allows the fluid system to flex and float with the
changing terrain and soil conditions. The accumulator 27 is
preferably centrally mounted so that when any single row unit moves
over an obstruction, the down-pressure cylinder 19 moves to
displace the hydraulic fluid along a common set of lines connecting
all row units. The gas in the accumulator is compressed at the same
time, allowing for isolation among the row units so that upward
movement of one row unit does not cause downward movement of other
row units. Although the illustrative hydraulic ram is
single-acting, it is also possible to use a double-acting ram, or a
single-acting ram in combination with a return spring.
[0038] Another advantage of the compact hydraulic
cylinder/accumulator unit is that it can conveniently mounted to
the same brackets that are provided in many row units for mounting
an air bag, to control the down pressure on the row unit. For
example, in FIG. 9, the brackets 50 and 51 on which the hydraulic
cylinder/accumulator is mounted are the brackets that are often
connected to an air bag, and thus the same row unit can be used
interchangeably with either an air bag or the hydraulic
cylinder/accumulator to control the down pressure on the row
unit.
[0039] FIG. 10 is a schematic of a hydraulic control system for
supplying pressurized hydraulic fluid to the cylinders 19 of
multiple row units. A source 100 of pressurized hydraulic fluid,
typically located on a tractor, supplies hydraulic fluid under
pressure to a valve 101 via supply line 102 and receives returned
fluid through a return line 103. The valve 101 can be set by an
electrical control signal S1 on line 104 to deliver hydraulic fluid
to an output line 105 at a desired constant pressure. The output
line is connected to a manifold 106 that in turn delivers the
pressurized hydraulic fluid to individual feed lines 107 connected
to the ports 71 of the respective hydraulic cylinders 19 of the
individual row units. With this control system, the valve 101 is
turned off, preferably by a manually controlled on/off valve V,
after all the cylinders 19 have been filled with pressurized
hydraulic fluid, to maintain a fixed volume of fluid in each
cylinder.
[0040] FIG. 11 is a schematic of a modified hydraulic control
system that permits individual control of the supply of hydraulic
fluid to the cylinder 19 of each separate row unit via feed lines
107 connected to the ports 71 of the respective cylinders 19.
Portions of this system that are common to those of the system of
FIG. 10 are identified by the same reference numbers. The
difference in this system is that each separate feed line 107
leading to one of the row units is provided with a separate control
valve 110 that receives its own separate control signal on a line
111 from a controller 112. This arrangement permits the supply of
pressurized hydraulic fluid to each row unit to be turned off and
on at different times by the separate valve 110 for each unit, with
the times being controlled by the separate control signals supplied
to the valves 110 by the controller 112. The individual valves 110
receive pressurized hydraulic fluid via the manifold 106, and
return hydraulic fluid to a sump on the tractor via separate return
line 113 connected to a return manifold 114 connected back to the
hydraulic system 100 of the tractor.
[0041] FIG. 12 illustrates on application for the controllable
hydraulic control system of FIG. 11. Modern agricultural equipment
often includes GPS systems that enable the user to know precisely
where a tractor is located in real time. Thus, when a gang of
planting row units 120 towed by a tractor 121 begins to cross a
headland 122 in which the rows 123 are not orthogonal to the main
rows 124 of a field, each planting row unit 120 can be turned off
just as it enters the headland 122, to avoid double-planting while
the tractor 121 makes a turn through the headland. With the control
system of FIG. 11, the hydraulic cylinder 19 of each row unit can
also be separately controlled to turn off the supply of pressurized
hydraulic fluid at a different time for each row unit, so that each
row unit is raised just as it enters the headland, to avoid
disrupting the rows already planted in the headland.
[0042] One benefit of the system of FIG. 11 is that as agricultural
planters, seeders, fertilizer applicators, tillage equipment and
the like become wider with more row units on each frame, often 36
30-inch rows or 54 20-inch rows on a single 90-foot wide toolbar,
each row unit can float vertically independently of every other row
unit. Yet the following row units still have the down force
remotely adjustable from the cab of the tractor or other selected
location. This permits very efficient operation of a wide planter
or other agricultural machine in varying terrain without having to
stop to make manual adjustment to a large number of row units,
resulting in a reduction in the number of acres planted in a given
time period. One of the most important factors in obtaining a
maximum crop yield is timely planting. By permitting remote down
force adjustment of each row unit (or group of units), including
the ability to quickly release all down force and let the row
cleaner quickly rise, e.g., when approaching a wet spot in the
field, one can significantly increase the planter productivity or
acres planted per day, thereby improving yields and reducing costs
of production.
[0043] On wide planters or other equipment, at times 90 feet wide
or more and planting at 6 mph or more forward speed, one row unit
must often rise or fall quickly to clear a rock or plant into an
abrupt soil depression. Any resistance to quick movement results in
either gouging of the soil or an uncleared portion of the field and
reduced yield. With the row unit having its own hydraulic
accumulator, the hydraulic cylinder can move quickly and with a
nearly constant down force. Oil displaced by or required by quick
movement of the ram is quickly moved into or out of the closely
mounted accumulator which is an integral part of each row unit. The
accumulator diaphragm or piston supplies or accepts fluid as
required at a relatively constant pressure and down force as
selected manually or automatically by the hydraulic control system.
By following the soil profile closely and leaving a more uniform
surface, the toolbar-frame-mounted row unit permits the planter row
unit following independently behind to use less down force for its
function, resulting in more uniform seed depth control and more
uniform seedling emergence. More uniform seedling stands usually
result in higher yields than less uniform seedling stands produced
by planters with less accurate row cleaner ground following.
[0044] The term row unit refers to a unit that is attached to a
towing frame in a way that permits the unit to move vertically
relative to the towing frame and other units attached to that same
towing frame. Most row units are equipped to form, plant and close
a single seed furrow, but row units are also made to form, plant
and close two or more adjacent seed furrows.
[0045] It will be evident to those skilled in the art that the
invention is not limited to the details of the foregoing
illustrated embodiments and that the present invention may be
embodied in other specific forms without departing from the spirit
or essential attributes thereof. The present embodiments are
therefore to be considered in all respects as illustrative and not
restrictive, the scope of the invention being indicated by the
appended claims rather than by the foregoing description, and all
changes which come within the meaning and range of equivalency of
the claims are therefore intended to be embraced therein.
* * * * *