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Description  |
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BACKGROUND OF THE INVENTION
I. Field of the Invention
This invention relates generally to farming row crop applicators having
adjustable track widths, and more specifically to row crop applicators
having adjustable length tie-rods adapted to the steerable axle.
II. Background of the Invention
Row crop applicators are widely used in the farming industry for applying
fertilizer about a field to maximize crop yield. Since different crops are
planted in rows having pre-selected row widths, depending on the crop to
be grown, the row crop applicator machinery needs to have adjustable track
widths such that the tires of the applicator can be driven in the rows
defined between the rows of crop. Typical row crop applicators have a
track width adjustable between 120 and 152 inches.
Four wheeled row crop applicators have an axle assembly including a tie-rod
extending between a pair of steering structures for maintaining a
pre-selected toe-in setting. Consequently, when the track width of the
steering assembly is adjusted in the longitudinal direction, the length of
the tie-rod needs to be adjusted in the longitudinal direction in step
therewith. Prior art steering axle assemblies are typically adjusted
hydraulically. However, presently available tie-rods typically comprise of
a rod telescopingly received within a tubular member, wherein a set pin
can be selectively removed therefrom such that the inner rod member can
telescope within the tubular member when the track width is adjusted. One
or more set pins are then subsequently reinserted through a pair of holes
defined in both the tubular member and the telescoping rod to secure the
inner rod to the tubular member. These holes are typically defined in 4
inch increments, wherein the operator has to manually insert and remove
the pins during the track width adjustment procedure.
One major problem with prior art equipment is that the toe-in setting
defined by the wheel assemblies needs to be re-set whenever the track
width is established in between a minimum and maximum setting. Further,
since the holes in the tie-rod assembly are defined every 4 inches, the
operator needs to repeatedly fine tune the track width adjustment until
the holes of the inner rod and the outer tubular member are perfectly
aligned so that the set pin can be disposed therein. These processes are
time consuming, tedious, and potentially dangerous as the operator needs
to be positioned beneath the front of the tractor chassis. Further, the
track width of the row crop applicator can only be adjusted in 4 inch
increments, and is not selectively adjustable to any position between an
inner and outer setting. Some crops are planted in rows as narrow as 24
inches, and since the track widths of tractor wheels can sometimes extend
up to 12 inches, a 4 inch track width adjustment increment does not
provide adequate fine tuning of a desirable track width.
Typically, independent contractors are hired by the farmer to treat a
field. The track width of the contractor's row crop applicator is usually
not initially appropriate for the intended field to be treated with
fertilizer when the contractor arrives to the field. Thus, the independent
contractor finds their self requiring to adjust the track width, and
resetting the toe-in. Treating several different fields in a day may
require setting several different track widths, which is time consuming
and inefficient. When the independent contractor is under severe time
limitations to treat many fields with fertilizer in a very narrow time
window, which can be dictated by the weather or other uncontrollable
circumstances, valuable time is lost during the repeated track width
adjustments. Thus, the independent contractor stands to benefit from the
present invention. However, even the farm owner can benefit from an
improved adjustable tie-rod arrangement since the typical farmer plants
more than one type of crop, each having different row widths. Hence,
having a row crop applicator with a precision adjustable track width would
benefit the average farmer as well.
OBJECTS
It is a principle object of the present invention to provide a row crop
applicator having a steering structure with an adjustable track width,
wherein the tie-rod can be selectively adjusted to any position in a
secure arrangement between a first and second track width setting.
Yet a further object of the present invention is to provide a locking
arrangement for securing the steering structure to maintain a
predetermined toe-in setting during the track width adjustment procedure.
It is a further object of the present invention to provide a row crop
applicator having an adjustable tie-rod assembly which does not require
the operator to leave the cab of the vehicle to facilitate adjustments of
the tie-rod assembly.
Still yet a further object of the present invention is to provide a row
crop applicator having an adjustable tie-rod assembly, wherein the tie-rod
assembly can be adjusted in the longitudinal direction in an asymmetrical
or symmetrical arrangement to facilitate distributing the load of the
vehicle in a balanced arrangement upon the wheels.
Other objects, features and advantages of the present invention will become
apparent to those skilled in the art through the Description of the
Preferred Embodiment, claims, and drawings herein, wherein like numerals
refer to like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a typical four wheeled row crop applicator
having an adjustable track width including a variably adjustable tie-rod
assembly;
FIG. 2 is a top view of a front steering axle assembly having a variable
track width and a variable tie-rod assembly;
FIG. 3 is a front view of the front wheel steering structure assembly shown
in FIG. 2 illustrating the arrangement of the hydraulic cylinders in
relation to the steering axle assembly and the telescoping tie-rod
assembly;
FIG. 4 is an exploded perspective view of the hydraulic network for
controlling the telescoping cylinders and the telescoping tie-rod, each
which are simultaneously hydraulically extended or retracted during the
track width adjustment procedures;
FIG. 5 is a partial sectional view of one hydraulic cylinder illustrating
the adjustable piston in the retracted position;
FIG. 6 is an end view taken along line 6--6 shown in FIG. 5;
FIG. 7 is a schematic view of the hydraulic system for controlling each of
the track adjust cylinders and each tie-rod cylinder, each half capable of
being controlled either independently or in unison with the other half;
and
FIG. 8 is an exploded front view of the steerable wheel locking arrangement
including a pair of eccentric cams which are rotatably secured with
respect to one another by a pin inserted therein to lock the wheels.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a perspective view of a row crop applicator is
generally shown at 10. Row crop applicator 10 has a front steering axle
assembly generally shown at 12, wherein a pair of wheels 14 define a track
width. The track width is adjustable to any position between an innermost
and outermost position, typically 120 to 152 inches. This track width is
adjustable by the operator using conventional hydraulic systems, which are
well-known in the art of row crop applicators.
Referring to FIG. 2, a top view of front wheel steering assembly 12 is
shown, illustrating an improved precisionally variable tie-rod assembly
according to the present invention. Front wheel steering assembly 12
includes a rigid tubular axle housing 20 extending laterally across and
secured to a tractor chassis 22, typically eight inches in diameter.
Axially disposed therein is a pair of telescoping tubular cylinders 24,
each extending from approximately a center of axle housing 20 and beyond a
respective distal end thereof, each approximately 6 inches in diameter.
Each cylinder 24 can be adjusted in the lateral direction from an
innermost position, as shown, outwardly in the lateral direction up to
approximately 16 inches to provide an overall track adjustment range of 32
inches. However, limitation to this adjustable track width range is not to
be inferred.
A steering structure 30 is rotatably coupled to the distal end of each
respective tube member 24. Each steering structure 30 is steered in unison
with the other, wherein each is maintained relative to the other to define
a toe-in setting. The toe-in can be selectively adjusted by adjusting the
length of either toe adjusting member 34. Each tubular member 24 can be
adjusted in the lateral direction, either independently or in unison with
the other, by injecting and removing hydraulic fluid from chambers of a
respective hydraulic cylinder 40, which will now be discussed in
considerable detail.
The novel features of the infinitely variable tie-rod assembly will now be
described in considerable detail. Still referring to FIG. 2, a pair of
hydraulic cylinders 40 are shown which are each fixedly attached at an
inner end to a bracket 42, wherein bracket 42 is secured and welded to the
periphery of axle housing 20. The inner end of each cylinder 40 has a
U-shaped bracket 44 extending therefrom and receiving the respective
bracket 42. A bolt 46 is selectively disposed through a pair of apertures
defined in U-shaped bracket 44 and member 42 to secure bracket 44 to
member 42.
The opposing end of each telescoping hydraulic cylinder 40 is securingly
coupled to telescoping member 24 via a bracket 50, which is similar to
bracket 42, and a U-shaped member 52, which is similar to U-shaped bracket
44, and which is secured to the distal end of an extendable piston rod 54.
Piston rod 54 is selectively adjustable in the longitudinal direction
within cylinder 40, and is axially disposed therein. By extending piston
rod 54 outward in the axial direction, using hydraulic fluid as will be
discussed shortly, bracket 52 is moved therewith to impart longitudinal
movement in step with tubular member 24.
The adjustable tie-rod assembly is further comprised of a rigid tubular
housing 60 having a pair of telescoping piston rods 62 axially defined
therein. Each rod 62 is securingly fastened to toe-in adjustment member
34, which in turn is pivotally secured to a respective bracket 64 of
respective steering structure 30. Each respective bracket 64 is secured
via welding to the respective steering structure 30, which steering
structure 30 is pivotally secured to the respective tubular axle member
24. It is particularly noted that both brackets 50 are rigidly secured to
the extended portion of the respective telescoping member 24. Thus, as one
telescoping member 24 is displaced a unit increment within axle housing
20, both respective rods 62 and rod 54 are adjusted in equal unit length
in the longitudinal direction as well. Hence, adjustment of one of the
members 24, 54 or 62 causes the other two members to be incremented in
step therewith. Again, the toe-in defined by each wheel can be selected by
using adjusting member 34, by rotating a hex nut 70 such that a rod 72 can
be axially displaced within member 34, wherein hex nut 70 is subsequently
resecured.
As will be discussed shortly, piston rod 54 can be axially displaced within
respective cylinder 40 by injecting and removing hydraulic fluid, such as
via port 80. Similarly, each piston rod 62 can be axially adjusted within
tie-rod housing 60 by injecting and removing hydraulic fluid from chambers
defined therewithin via ports 82, 84, 86 and 88. A pair of hydraulic lines
90 are provided for communicating hydraulic fluid between a chamber
defined on each side of a piston, which piston is positioned within
housing 60 and about respective piston rod 62. Similarly, a hydraulic
passageway 92 is provided for communicating hydraulic fluid between a pair
of chambers defined on each side of a piston integrally defined within
respective cylinder 40, each piston being defined about a respective rod
54.
Steering is accomplished by a pair of hydraulic cylinders 96, which cause
each respective steering assembly 30 to pivot about a king pin 98, and
with respect to the distal end of respective tubular member 24, as shown
in FIG. 3. Each hydraulic cylinder 96 includes an axially received piston
rod 100 which is displaced in a longitudinal direction, in unit steps with
one another, to facilitate a steering structure, which is well-known in
the art.
Referring to FIG. 3, a novel locking arrangement is shown at 102, wherein
sectional view 8--8 is shown and will be described shortly. Locking
structure 102 provides a unique arrangement for selectively locking each
respective steering structure 30 during a track width adjustment procedure
with respect to tubular member 24 when each steering structure 30 is
facing forward such that vehicle 10 is driving straight. Locking structure
102 will be described shortly.
Now referring to FIG. 4, the hydraulic arrangement for controlling the
extension of cylinder rods 54 within cylinders 40, and tire-rods 62 within
tie-rod housing 60 will now be discussed in considerable detail. As shown,
hydraulic fluid is injected or extracted via a first pair of passageways
110, and a second pair of passageways 112. To impart longitudinal movement
of piston rod 54 and extend bracket 52 from the cylinder housing 40,
hydraulic fluid is injected via respective line 110 into a lower aperture
defined in the proximal end of respective cylinder 40. Concurrently,
hydraulic fluid is removed via an aperture 116 defined in an upper
proximal end of respective cylinder 40. The lower and upper apertures of
each cylinder 40 communicate hydraulic fluid to chambers defined on
opposite sides of a piston defined about each respective piston rod 54, as
will be described shortly in reference to FIG. 5. Similarly, to retract
rods 54 and 62 within the respective housings, fluid is injected and
retracted in opposite directions via lines 110-112.
To increase the track width of row crop applicator 10, hydraulic fluid is
injected via a respective line 110 into the respective cylinder 40, and
removed via line 112. Also concurrently, hydraulic fluid is injected into
the respective half of tie-rod housing 60 via apertures 82 and 88,
depending on which, or both, steering assemblies 30 are to be extended,
and simultaneously retracted from apertures 84, 86.
For instance, if only the right steering structure is to be extended,
hydraulic fluid is only injected into and removed from the right cylinder
40, and the right half of tie-rod 60. If a symmetrical adjustment is
desired, equal amounts of hydraulic fluid are injected and removed from
each of the respective chambers of each cylinder 40 and tie-rod housing 60
to get an equal adjustment of each steering assembly 30 in reference to a
mid-section of housing 20. As shown in FIG. 4, a variety of hydraulic
couplings are provided for adapting hydraulic lines between splitters, and
to each of the ports defined in cylinders 40 and tie-rod housing 60.
Because the longitudinal adjustments of each rod 54 within cylinder 40, and
of tie-rod rods 62 within housing 60 is hydraulically driven, an equal
amount of hydraulic fluid is injected into the chamber on one-half of the
internal piston as is removed from the chamber opposite the piston in a
closed system arrangement.
Now referring to FIG. 5, cylinder 40, which is similar to the pistons
defined in tie-rod housing 60, will be described in considerable detail.
Cylinder 40 has disposed therein a piston 120 defining a first chamber
122, which is in communication with port 116, and a second chamber 126
which is isolated from first chamber 122. Second chamber 126 is in
communication with port 128 via hydraulic passageway 92. A pair of 90
degree couplings 130 are provided for adapting conduit 92 to cylinder 40
in a low profile arrangement. A bulk head 132 is provided for defining
each opening 116 and 128, and which is secured to the outer housing of
cylinder 40. A wearband 133 is provided about piston 120, as is a seal
134. A rod spacer member 136 is secured within cylinder 40 and chamber 126
for defining a maximum extension of piston 120. A seal 138 is provided
about stop spacer member 136 for sealing hydraulic fluid within chamber
126 in combination with seal 134.
By injecting hydraulic fluid into port 116, and consequently into first
chamber 122, and simultaneously removing hydraulic fluid from second
chamber 126 via passageway 92 and port 128, longitudinal movement of
piston rod 54 is generated. Hydraulic pressure developed in first chamber
122 urges piston 120 to slide in the axial direction, towards the right to
extend piston rod 54, and respective bracket 52 away from the distal end
of cylinder 40. This process is done to impart longitudinal movement of
the respective tubular housing member 24 such that axle member 24 is
extended outward from chassis 22 to increase the track width of tractor
10. The other cylinder 40 may be similarly extended, simultaneously if
desired, if it is desired to symmetrically increase the track width.
However, either cylinder 40 can be individually controlled with the
respective tubular member 24, which will be described further shortly.
Conversely, piston rod 54 can be retracted within cylinder 40 by removing
hydraulic fluid from first chamber 122 and injecting hydraulic fluid into
second chamber 126 in a similar fashion. When piston rod 54 is retracted
within cylinder 40, the respective tubular member 24 is retracted within
axle housing 20 in unit step therewith.
Referring now to FIG. 7, a schematic lay out of the hydraulic system is
illustrated to further illustrate how hydraulic fluid is communicated
between a hydraulic controller and source 140 and tie-rod housing 60, and
each track adjust cylinder 40. As schematically illustrated, either the
left half, or right half, or both tie-rod cylinder 60 and track adjust
cylinders selectively can be controlled. To extend one tie-rod cylinder
rod 62 and the respective piston rod 54 of the corresponding cylinder 40,
hydraulic fluid is communicated from hydraulic controller 140 to a pair of
check valves 150. Consequently, a pilot valve opens a corresponding second
check valve 152 such that hydraulic fluid can be injected into one chamber
and removed from the other chamber of each cylinder to impart longitudinal
movement of the piston rods within each respective housing. Thus, the
corresponding piston rod 54 and 62 will be incremented in unit step with
one another. To retract each respective piston rod 54 and 62, hydraulic
fluid is communicated to each check valve 152, which causes the pilot
valve to unlock the corresponding check valve 150, such that hydraulic
fluid can be communicated in the opposite direction. Each rod is locked in
place when fluid is not communicated due to check valves 150 and 152 being
closed.
Still referring to FIG. 7, either or both sets of tie-rod cylinders and
track adjust cylinders can be selectively adjusted in the longitudinal
direction in any position between an innermost and outermost setting.
Again, each tie-rod cylinder rod 62 and track adjust cylinder rod 54 are
adjusted in step with the respective tubular member 24. Thus, the overall
length of the tie-rod assembly will be extended or reduced equally to the
length adjustment of the axle housing formed by housing 20 and each
tubular member 24. The track width can be ascertained from the cab of
vehicle 10 by observing graduated indicia 153 defined on a surface of each
rod 24 projecting from housing 20. (See FIG. 3). Hydraulic controller 140
resides in the cab of the row crop applicator vehicle 10, wherein
hydraulic solenoid switches are implemented to electronically control the
communication of hydraulic fluid via hydraulic lines 160 and 162 to each
of respective check valves 152 and 150. Thus, the hydraulic assembly can
be remotely controlled within the cab by the operator.
Now referring to FIG. 8, sectional view 8--8 shown in FIG. 3 of locking
structure 102 will now be described in considerable detail. A first plate
170 having an aperture 173 and a second plate 172 having an aperture 176
are illustrated, wherein first plate 170 is secured about the tubular
sleeve 171 which receives king pin 98. This tubular sleeve 171 is an
integral part of tubular member 24, as shown in FIG. 3. Plate 170 is
stationary in that steering rotation occurs about it. Second plate 172 is
part of the steering structure 30, as shown in FIGS. 2 and 3. Second plate
172 is rotatable about the king pin. A steering lock hub 174 is rotatably
received within an aperture 176 defined through a distal end of plate 172.
Steering lock hub 174 has an eccentrically defined opening 178 for
receiving a steering lock sleeve 180 as shown. Steering lock sleeve 180
also has an eccentrically defined opening 182 for receiving a lock pin
184.
An pneumatic cylinder 188, which is remotely controlled from within the cab
of vehicle 10, has a extendable shaft 190 which is received within a
tubular opening 192 of locking pin 184. Consequently, when pneumatic
cylinder 188 is engaged, shaft 190 will project therefrom and project
locking pin 184 into both opening 182 of steering lock sleeve 180, which
is received in opening 178 of steering lock hub 174, and into aperture 173
but only when each eccentrically shaped opening is aligned with one
another and opening 173. Being as the setting of proper toe-in establishes
the rotatable relationship of plate 170, which is stationary, and of plate
172 which rotates with steering or the setting of toe-in, the relationship
of the holes in said plates 170 and 172 needs to be adjustable in order
for a common axis to be established. Such alignment only occur when each
of the steering structures 30 of tractor 10 are facing straight and in the
forward direction.
Pneumatic cylinder 188 will attempt to project locking pin 184 into each
opening 182 and 178 until the operator properly aligns each steering
assembly 30 in a forward direction. This feature is provided such that the
predetermined toe-in adjustment will not be disturbed from track
adjustment forces overriding the steering cylinders during a subsequent
adjustment of the track width, as previously described, even when the
track width is adjusted to define the track width between the minimum and
maximum settings. Pneumatic cylinder 188 is controlled via a pair of air
lines 193, which selectively couple air between a control source 195,
which is remotely controlled from within the cab of the vehicle 10.
Feedback is provided to the operator in the cab via a first conductor 194
and a second conductor 196 to a respective LED 198 and 200. For instance,
first LED 198 can be a green LED which is illuminated when shaft 190 is in
the retracted position, indicating that the steering assembly is not
locked. Similarly, LED 200 can be a red LED which is illuminated when
shaft 190 is extended, thus positioning locking pin 184 within openings
182 and 178, to indicate the steering assembly is locked. A hex stop 202
is secured to plate 172 and is provided for aligning and securing steering
lock hub 174. A washer 204 and a hex bolt 206 is provided for securing hex
stop 206 to second plate 172. Hex stop 202 and cam 180 are illustrated in
FIG. 2 with pneumatic cylinder 188 removed.
In summary, a selectable tie-rod assembly has been described in
considerable detail which can be extended or retracted in unison with the
steering axle assembly which establishes the track width. Since the
tie-rod assembly is selectively adjustable to any position between a
maximum and minimum track width position, the operator can set a precise
track width which is appropriate for the field to be treated. Further, the
operator need not leave the cab to lock and unlock telescoping members of
a tie-rod arrangement, which is time consuming, frustrating and
inefficient, and sometimes dangerous. Either half of the tie-rod assembly
can be extended or retracted individually or simultaneously, to compensate
for the loading of the tractor as well. Thus, symmetrical or asymmetrical
adjustment of the tie-rod assembly can be provided. A further feature of
the present invention is the unique locking feature to lock the steering
structure in a forward position while adjusting the track width to any
track width setting. The exact track width can be readily observed from
the cab of the tractor by observing the indicia disposed on the extendable
piston rod of the wheel assembly.
This invention has been described herein in considerable detail in order to
comply with the Patent Statutes and to provide those skilled in the art
with the information needed to apply the novel principles and to construct
and use such specialized components as are required. However, it is to be
understood that the invention can be carried out by specifically different
equipment and devices, and that various modifications, both as to the
equipment details and operating procedures, can be accomplished without
departing from the scope of the invention itself.
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