U.S. patent application number 09/740449 was filed with the patent office on 2002-06-20 for floating hitch for agricaltural implement.
Invention is credited to Ankenman, Thomas W..
Application Number | 20020074139 09/740449 |
Document ID | / |
Family ID | 24976567 |
Filed Date | 2002-06-20 |
United States Patent
Application |
20020074139 |
Kind Code |
A1 |
Ankenman, Thomas W. |
June 20, 2002 |
FLOATING HITCH FOR AGRICALTURAL IMPLEMENT
Abstract
The implement has a main frame supported at the rear by
ground-engaging transport wheels and at the front by
ground-engaging gauge wheels. A hitch is pivotally connected to the
front end of the main frame so that the hitch and frame can flex
relative to one another when the towing tractor experiences
different terrain than the main frame. A self-leveling mechanism is
normally disengaged when the implement is in its field operating
position so that the hitch is free to float relative to the frame
during terrain changes. However, when engaged, the self-leveling
mechanism operates to maintain the main frame level as the
transport wheels are lowered to raise the main frame into its
transport position. A latch, remotely actuatable from the tractor
seat, determines whether the implement is in its self-leveling mode
or floating hitch mode.
Inventors: |
Ankenman, Thomas W.;
(Hutchinson, KS) |
Correspondence
Address: |
HOVEY, WILLIAMS, TIMMONS & COLLINS
Suite 400
2405 Grand
Kansas City
MO
64108
US
|
Family ID: |
24976567 |
Appl. No.: |
09/740449 |
Filed: |
December 19, 2000 |
Current U.S.
Class: |
172/452 ;
172/482; 172/677 |
Current CPC
Class: |
A01B 51/04 20130101;
A01B 63/24 20130101; A01B 63/22 20130101 |
Class at
Publication: |
172/452 ;
172/482; 172/677 |
International
Class: |
A01B 059/00 |
Claims
1. In a farm implement, the improvement comprising: a frame; a rear
transport wheel assembly disposed to support the rear of the frame
in a lowered, operating position, said transport wheel assembly
being vertically adjustable relative to the frame to cause raising
and lowering of the frame between said lowered, operating position
and a raised transport position; a front gauge wheel assembly
disposed to support the front of the frame in said lowered,
operating position and to be supported off the ground by the frame
when the frame is in its raised, transport position; a hitch at the
front of the frame for coupling the implement with a towing
vehicle, said hitch being pivotally connected to the frame for
vertical swinging movement relative to the frame about a transverse
horizontal axis; and selectively engageable self-leveling mechanism
operable when disengaged to allow the implement to flex freely
about said transverse axis when the frame is in said operating
position and the implement encounters changes in the terrain
relative to the towing vehicle and operable when engaged to
operably interconnect the transport wheel assembly and the hitch in
a manner to maintain the frame substantially level as it is raised
and lowered between said operating and transport positions in
response to vertical adjustment of the transport wheel
assembly.
2. In an implement as claimed in claim 1, said self-leveling
mechanism including a motion-transmitting linkage leading from the
transport wheel assembly to the hitch and a selectively actuatable
latch operable when actuated to lock the linkage and the hitch
against movement relative to one another and operable when
deactuated to allow the hitch and the frame to pivot freely
relative to one another about said transverse axis.
3. In an implement as claimed in claim 2, said linkage including a
lever pivotally coupled with the hitch, said latch being operable
when actuated to lock the lever against pivoting movement relative
to the hitch and operable when deactuated to allow the lever to
pivot relative to the hitch.
4. In an implement as claimed in claim 3, said latch including a
hydraulic cylinder for effecting actuation and deactuation of the
latch.
5. In an implement as claimed in claim 3, said latch including a
strut pivotally connected at one end to the hitch and having a pair
of longitudinally spaced stops at the other end, said lever being
received between said stops and having a reduced width portion that
is narrower than the distance between said stops and an enlarged
width portion spaced axially from the reduced width portion that
substantially corresponds in width to the distance between said
stops, said latch further including a device for selectively
shifting the strut along the lever to place the stops either at
said reduced width portion providing lost motion pivoting movement
of the lever relative to the strut or at said enlarged width
portion precluding pivoting movement of the lever relative to the
strut.
6. In an implement as claimed in claim 5, said stops comprising
rollers.
7. In an implement as claimed in claim 5, said device comprising a
hydraulic piston and cylinder assembly.
8. In an implement as claimed in claim 1, said gauge wheel assembly
having depth control apparatus operably coupled therewith for
vertically adjusting the gauge wheel assembly relative to the frame
and for holding the gauge wheel assembly in a selected position of
vertical adjustment, said transport wheel assembly including a
wheel arm, a lug swingable relative to said frame, and a hydraulic
piston and cylinder assembly between said lug and said wheel arm,
said gauge wheel assembly having a rigid link connecting the same
with said lug of the transport wheel assembly whereby to hold said
lug in a fixed position relative to said frame except during
vertical adjustment of the gauge wheel assembly by said depth
control apparatus, at which time the lug is simultaneously adjusted
with the gauge wheel assembly.
Description
TECHNICAL FIELD
[0001] The present invention relates to farm implements and, more
particularly, to tillage implements and like devices in which it is
important to penetrate the soil at a uniform depth in all regions
of the implement regardless of changes in terrain that may be
encountered between the towing vehicle and the implement.
BACKGROUND
[0002] Tillage implements such as field cultivators typically have
relatively large rectangular frames that have a significant
front-to-rear dimension. In order to have the ground penetrating
tools of the frame at the same depth in both the front and rear, it
is a fairly common practice to utilize gauge wheels at the front of
the main frame to assist the main transport wheels that are
positioned further back toward the rear of the frame. By having
both the transport and gauge wheels engaging the ground when the
main frame is at its lowered, operating position, the main frame
can remain substantially level as the towing tractor encounters
terrain changes not yet experienced by the implement. A transverse
horizontal pivot between the main frame and the tongue or hitch
allows the hitch to float up and down about the transverse pivot as
the tractor and main frame seek their own level conditions.
[0003] In known floating hitch arrangements, the hitch is in a
floating mode at all times. When the main frame is raised into a
transport position, the gauge wheels remain on the ground along
with the main transport wheels. Thus, the gauge wheels remain in
contact with the ground during over-the-road travel, which is not a
desirable situation because the gauge wheels are typically of the
castering variety and tend to wobble and gyrate back and forth at
road speeds unless somehow locked in straight ahead positions.
Furthermore, since the linkages that connect the gauge wheels to
the main frame must be operated each time the main frame is raised
and lowered, such linkages will suffer premature wear unless they
are heavy duty components, which necessarily increases costs.
[0004] Yet, it is important to keep the main frame substantially
level when in its transport position so that adequate ground
clearance is achieved between the tools and the ground at all
regions of the machine. On known equipment, unless the gauge wheels
remain in contact with the ground at such time, the unsupported
front end of the main frame can nose dive about the transverse
flotation pivot. What is needed in the art is a way of keeping the
main frame level in the transport position even though the gauge
wheels are off the ground, yet allow the main frame to remain level
in the field position while the hitch floats up and down as the
tractor experiences changes in terrain relative to the main
frame.
SUMMARY OF THE INVENTION
[0005] The present invention contemplates overcoming the
deficiencies of the prior art by providing a floating hitch
arrangement that can be selectively engaged and disengaged. Thus,
in the field operating position, the hitch can be disposed in a
floating mode in which it is free to swing up and down relative to
the main frame as the gauge wheels and transport wheels maintain
the main frame in a level attitude. Then, for transport, the hitch
can be locked into a self-leveling mode with the main frame such
that as the main frame is raised and lowered, carrying the gauge
wheels therewith, the angular position of the hitch relative to the
main frame is under the control of self-leveling mechanism that
causes the main frame to remain level in all positions of vertical
adjustment.
[0006] The self-leveling mechanism includes linkage that transmits
motion of the transport wheel arms to the hitch when the
self-leveling mechanism is engaged for transport. On the other
hand, when the self-leveling mechanism is disengaged for field
operations, there is no motion-transmitting connection between the
wheel arms and the hitch such that the hitch can freely pivot up
and down while the wheel arms remain in a fixed position relative
to the main frame. A latch carried on the hitch can be locked and
unlocked to correspondingly engage and disengage the self-leveling
mechanism, and in a preferred form of the invention such latch
includes a remotely actuatable hydraulic piston and cylinder
assembly so that the self-leveling mechanism can be engaged and
disengaged from the tractor seat. When the latch is disengaged, an
upstanding lever pivoted to the hitch and forming part of the
control linkage of the self-leveling mechanism is free to swing
back and forth relative to the hitch as the hitch floats with
terrain changes. On the other hand, when the latch is engaged, the
lever is locked up and cannot swing relative to the hitch such that
movement of the wheel arms to raise and lower the main frame is
correspondingly transmitted to the hitch, causing the main frame to
remain level. In a particularly preferred embodiment of the
invention, a strut that maintains the lever rigid to the hitch when
the self-leveling mechanism is engaged has one end that can move up
and down along the lever between locking and released positions.
The lever has a certain amount of lost motion relative to the strut
when the strut is in its released position, but when the strut is
in the latched position the lever is immobilized relative to the
hitch. The gauge wheels are linked mechanically to the transport
wheel assemblies in such a way that, even though the transport
wheels are hydraulically swung up and down relative to the main
frame during adjustment of the main frame between its operating and
transport positions, the gauge wheels remain at a constant position
and thus are raised off the ground when the main frame is raised.
On the other hand, when the gauge wheels are depth adjusted
relative to the main frame, the linkage between the gauge wheels
and the transport wheel assemblies responsively causes a
corresponding amount of depth adjustment of the transport wheels as
well.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a side elevational view of an implement
incorporating the principles of the present invention connected to
a towing tractor and illustrating the nature of the floating hitch,
portions of the implement being removed for clarity;
[0008] FIG. 1 a is an enlarged, fragmentary elevational view of the
implement illustrating the floating action of the hitch;
[0009] FIG. 2 is a side elevational view similar to FIG. 1 but
illustrating the floating action of the hitch as the implement
moves over a rise relative to the tractor;
[0010] FIG. 2a is an enlarged, fragmentary view thereof;
[0011] FIG. 3 is a fragmentary top plan view of the implement with
its wing sections fragmentarily shown;
[0012] FIG. 4 is a generally fore-and-aft cross sectional view
through the implement with the main frame in the operating position
and taken substantially along line 4-4 of FIG. 3;
[0013] FIG. 5 is a elevational view of the implement substantially
similar to FIG. 4 but showing the main frame raised into its
transport position;
[0014] FIG. 6 is a generally fore-and-aft cross sectional view of
the implement in the operating position with the self-leveling
mechanism disengaged to permit free floating action by the hitch
and taken substantially along line 6-6 of FIG. 3;
[0015] FIG. 7 is a cross sectional view of the implement similar to
FIG. 6 with the main frame in the field working position but
showing the self-leveling mechanism engaged in preparation for
raising of the main frame into the transport position;
[0016] FIG. 7a is an enlarged, fragmentary view of the implement in
its FIG. 7 position illustrating details of construction of the
latch for locking the self-leveling mechanism in its engaged
condition;
[0017] FIG. 8 shows the self-leveling mechanism engaged and the
main frame raised up into its transport position; and
[0018] FIG. 9 is an isometric, partially exploded view of portions
of the center frame section of the implement illustrating details
of construction.
DETAILED DESCRIPTION
[0019] The implement 10 selected for illustration is a field
cultivator. However, as well understood by those skilled in the
art, the principles of the present invention may be applied to many
different kinds of implements, the field cultivator being but one
example. Furthermore, it will be apparent that the principles of
the present invention may be applied beneficially to single frame
section implements or multiple frame section implements alike, the
presence or absence of such folding wing sections and the number
thereof being irrelevant to the principles of the present
invention. It will be recognized, however, that in some respects
the more wing sections provided in the implement, the greater the
benefit achieved by the present invention. In the illustrated
embodiment, a multiple frame section implement is disclosed as
shown in FIG. 3 wherein the main frame 12 is shown to include a
center frame section 14 and at least a pair of wing sections 16 and
18 hingedly connected to center section 14 in a well known
manner.
[0020] Center section 14 of main frame 12 is generally rectangular
in plan as shown in FIG. 3. A generally triangular hitch 20 is
pivotally connected to the front of center section 14 by a pair of
horizontal, transverse, aligned pivots 22 that define an axis of
vertical swinging movement of the hitch 20 relative to frame 12,
and vice versa. A draw bar coupling 24 is provided at the front end
of hitch 20 for connecting implement 10 to a towing tractor 26 or
other vehicle. A number of tillage tools 28 in the form of shanks
or tines are mounted on frame section 14 for penetrating the ground
as implement 10 is drawn by tractor 26.
[0021] A pair of transport wheel assemblies 30 support the rear of
frame section 14, while a pair of gauge wheel assemblies 32 support
the front of frame section 14. Each transport wheel assembly 30
includes a pair of ground wheels 34 and 36 that are slightly
mutually staggered in a fore-and-aft direction and comprise part of
a walking beam arrangement as well known by those skilled in the
art.
[0022] As shown particularly in FIGS. 4, 5 and 9, each transport
wheel assembly 30 includes a wheel arm 38 supporting the wheels 34
and 36 at its lower end and pivotally attached at its upper end to
the center frame section 14 via a transverse pivot 40. As shown in
FIG. 9, each pivot 40 is supported by a bolt on bracket 42 and a
welded on bracket 44, both of which are attached to and supported
by a cross beam 14a of the center frame section 14. A second welded
on bracket 46 is spaced inboard from each bracket 44 along the beam
14a, each pair of brackets 44,46 having a pair of transversely
aligned holes 48 (FIG. 9) for a purpose yet-to-be described. The
two wheel arms 38 are rigidly interconnected by a transversely
extending rocker bar 50 that extends parallel to but in front of
and below the frame beam 14a. A generally centrally disposed
bracket 52 on beam 14a (FIGS. 6, 7, 8 and 9) has a lower pivot 54
that swingably supports a lug 56 fixed to and projecting rearwardly
from the rocker bar 50. Thus, bracket 52 provides central support
for the rocker bar 50 during up and down movement thereof with the
wheel arms 38.
[0023] Wheel arms 38 are raised and lowered relative to the center
frame section 14 by hydraulic cylinders 58 (FIGS. 4 and 5). Each
cylinder 58 has its anchor end pivotally attached to a lug 60
adjacent the lower end of wheel arm 38 and its upper rod end
pivotally secured to an inverted, generally Y-shaped lug or fork
62. Each fork 62 is, in turn, pivotally attached at its lower end
to a corresponding pair of the brackets 44,46 by aligned transverse
pivot bolts 64 held in the aligned holes 48 in brackets 44,46 (FIG.
9). Forks 62, although being pivotally attached to the center frame
section 14, are rendered immobile and effectively fixed with
respect to the frame section 14 most of the time, as will
hereinafter be explained in more detail. Accordingly, extension and
retraction of wheel cylinders 58 causes vertical adjustment of
transport wheel assemblies 30 relative to implement main frame
12.
[0024] Each gauge wheel assembly 32 is attached to the front of
center section 14 by an upwardly and forwardly projecting mount 66
fixed at its lower end to a cross beam 14b of center frame section
14. Each gauge wheel assembly 32 includes a caster wheel 68 having
an upright spindle 70 captured within a sleeve 72 for swiveling
movement about an upright axis in a known manner. Sleeve 72 is in
turn coupled with the mount 66 via a parallel linkage 74 for up and
down adjusting movement relative to center frame section 14. A
depth control apparatus 76 of known construction is coupled between
the center section 14 and gauge wheel assembly 32 for adjusting the
latter up and down relative to frame section 14 and for holding the
same in a selected position of vertical adjustment, thus
controlling the depth of penetration of the tools 28 at the front
of frame section 14. Depth control apparatus 76 includes a ratchet
jack 78 that may be manually operated when adjustment of the gauge
wheel assembly 32 is desired.
[0025] A rigid, fore-and-aft extending link 80 for each gauge
assembly 32 and transport wheel assembly 30 is connected between
the fork 62 of transport wheel assembly 30 and an upright member 82
of depth control apparatus 76. Consequently, ratchet jack 78
normally holds the corresponding gauge wheel assembly 32 and fork
62 immobilized relative to center frame section 14. However, when
ratchet jack 78 is operated to vertically adjust gauge wheel
assembly 32 for depth control purposes, a corresponding adjustment
of fork 62 occurs, thus correspondingly causing depth adjustment of
the transport wheel assembly 30. It will be noted in this respect
that adjustment of the angular position of the fork 62 by depth
control apparatus 76 has the effect of changing the height of the
frame section 14 above the ground when the implement is in its
lowered operating position of FIG. 4, as well as when it is in its
raised, transport position of FIG. 5. It is contemplated that
cylinder 58 will be fully retracted when the implement is in the
working position of FIG. 4, and fully extended when in the
transport position of FIG. 5.
[0026] In accordance with the present invention, implement 10 may
be selectively placed in either a self-leveling mode or a floating
hitch mode. In the preferred embodiment, such selection of modes is
accomplished remotely from the driver's seat of tractor 26.
Selectively engageable and disengageable self-leveling mechanism
for providing this feature is denoted generally by the numeral 84
and broadly includes a motion-transmitting linkage leading from the
transport wheel assemblies 30 of center section 14 to hitch 20 and
a selectively actuatable latch 88 for selectively locking the
linkage 86 in the self-leveling mode. When linkage 86 is unlocked,
implement 10 is disposed in its floating hitch mode in which main
frame 12 and hitch 20 can flex relative to one another about the
horizontal transverse axis defined by pivots 22.
[0027] Beginning at the rear of the machine, and with initial
reference to FIG. 9, it will be seen that linkage 86 includes a
generally upright link 90 pivotally connected at its lower end to
rocker bar 50, a somewhat reversely L-shaped bell crank 92 pivoted
to the upper end of the bracket 52 by a pivot 94, a rigid,
fore-and-aft extending link 96 connected to the upwardly projecting
leg of bell crank 92, and a generally upstanding lever 98 (FIGS. 1a
and 2a) connected to link 96 at its forwardmost end. Lever 98 is
connected to hitch 20 by a pivot 100 for fore-and-aft swinging
movement. The link 96 may be longitudinally adjusted somewhat using
adjusting nuts 102 which function in a manner well understood by
those skilled in the art. The width of lever 98 varies in a
fore-and-aft direction, tapering from a wide portion 104 generally
adjacent its upper end to a narrow portion 106 adjacent its lower
end.
[0028] Latch 88 includes a strut 108 connected at its forward end
by a pivot 110 to hitch 20 so that strut 108 can swing up and down
relative to hitch 20. Adjacent its rearmost end, strut 108 is
provided with a pair of limit rollers 112 and 114 that are spaced
apart in a fore-and-aft direction and are disposed on opposite
fore-and-aft sides of lever 98. The distance between rollers 112
and 114 generally corresponds to the fore-and-aft width of lever 98
in its wide portion 104. Thus, when strut 108 is in its lowered
position of FIGS. 1, 1a, 2, 2a and 6 corresponding to a deactuated
condition of latch 88, lever 98 is free to rock back and forth in a
lost motion manner between the limits presented by rollers 112, 114
as maybe seen by comparing FIGS. 1, 1a and 2, 2a. On the other
hand, when strut 108 is in its raised position of FIGS. 7, 7a and 8
corresponding to the actuated condition of latch 88, rollers 112
and 114 are disposed closely adjacent front and rear extremities of
lever 98 in wide portion 104 thereof so as to preclude any swinging
motion of lever 98 relative to hitch 20.
[0029] Although a variety of means may be utilized to actuate and
deactuate latch 88, in the preferred embodiment a hydraulic
cylinder 116, operable from the tractor seat, is utilized for that
purpose. Cylinder 116 is pivotally connected between the front end
of center frame section 14 on the one hand and the rearmost
extremity of strut 108 in the vicinity of roller 114 on the other
hand. For convenience, latch cylinder 116 and wheel lift cylinders
58 may be connected in the same hydraulic circuit controlled by the
same operating lever (not shown) at the tractor seat. Although
connecting latch cylinder 116 and wheel cylinders 58 in a
continuously parallel fluid flow relationship will work, best
results have been obtained when a sequencing valve (not shown) is
made a part of the parallel fluid flow circuit to assure that latch
cylinder 116 always extends (to actuate to latch 88) before wheel
cylinders 58 extend to raise the implement. Likewise, during
lowering of the implement from its transport position of FIGS. 5
and 8, the sequencing valve assures that latch cylinder 116 will
only retract (to deactuate latch 88) after wheel cylinders 58 have
first been fully retracted and the implement is lowered back down
to its working position of FIGS. 1, 1a, 2, 2a, 4 and 6. The
sequencing valve itself forms no part of the present invention per
se and is readily available as an off-the-shelf item to those
skilled in the art. One suitable sequencing valve is available from
Prince Manufacturing Corporation of Sioux City, Iowa as Model No.
RD1008SH (IPED).
[0030] Operation:
[0031] During field operations, implement 10 is operated with main
frame 12 in its lowered operating position as shown in FIGS. 1, 1a,
2, 2a, 4 and 6. Self-leveling mechanism 84 is disengaged at this
time such that implement 10 is in its floating hitch mode with
hitch 20 free to pivot relative to main frame 12 about the
horizontal transverse axis defined by pivots 22. Latch cylinder 116
is fully retracted at this time so that latch 88 is deactuated with
strut 108 located at the lower end of upstanding lever 98.
Consequently, as implement 10 flexes about pivots 22 as the
implement and tractor experience changes in terrain relative to one
another as shown in FIGS. 1 and 2, lever 98 is free to swing
fore-and-aft between the limits defined by rollers 112,114 so as to
accommodate the floating hitch action. This enables tillage tools
28 throughout main frame 12 to be maintained at the same depth
inasmuch as main frame 12 remains level.
[0032] When the end of a row is reached, or when the implement is
to be readied for over-the-road travel, it is a simple matter to
engage and utilize self-leveling mechanism 84, as illustrated in
FIGS. 6-8. In FIG. 6, latch cylinder 116 is in its deactuated,
fully retracted condition, causing strut 108 to be at the lower end
of lever 98. By then actuating cylinder 116, strut 108 is lifted
about its pivotal connection 110 until limit rollers 112,114 are
located at the wide portion 104 of lever 98 as shown in FIGS. 7 and
7a. It is to be noted that although FIG. 6 illustrates the
implement in a level condition throughout its entire length, the
machine need not be in this condition before self-leveling
mechanism 84 can be engaged.
[0033] Once latch 88 is actuated, self-leveling mechanism 84 is
effectively engaged. Thus, as wheel cylinders 58 then extend to
raise the main frame 12 to its transport position, the downward
swinging motion of wheel arms 38 and rocker bar 50 is translated
into forward motion of link 96 through bell crank 92. However,
inasmuch as lever 98 is locked in its immobilized condition at this
time, such forward motion of link 96 is transmitted down through
lever 98 to hitch 20. This reaction causes the implement to buckle
about pivots 22 as illustrated in FIG. 8 as the main frame 12
remains level. It will be noted that as the rear end of hitch 20
rises during such leveling action, such movement is permitted by
virtue of a transverse pivotal connection between hitch coupling 24
and hitch 20. With the implement in the fully raised transport
position of FIG. 8, tools 28 throughout all regions of main frame
12 are raised up into a position providing excellent ground
clearance.
[0034] In order to return the implement to its field operating
position, wheel cylinders 58 are retracted, causing the main frame
12 to be lowered relative to transport wheels 30. Inasmuch as lever
98 remains locked at this time, self-leveling mechanism 84
continues to function and maintains the main frame 12 level until
it is fully lowered into the operating position. Once wheel
cylinders 58 have fully retracted, latch cylinder 116 retracts,
effectively deactuating latch 88 by lowering strut 108 until limit
rollers 112,114 are at the bottom end of lever 98 adjacent narrow
portion 106. At that time, the floating hitch mode is
re-established such that hitch 20 and main frame 12 are once again
able to flex freely relative to one another about the transverse
axis defined by pivots 22.
[0035] It is to be noted that gauge wheel assemblies 32 are on the
ground only when main frame 12 is in its lowered operating
position. As wheel cylinders 58 are extended during a lift cycle so
as to effectively lower transport wheel assemblies 30 relative to
frame 12, gauge wheel assemblies 32 do not correspondingly lower.
Instead, they remain set at the height established by ratchet jack
78 of depth control mechanism 76. Consequently, when main frame 12
is in its transport position of FIGS. 5 and 8, gauge wheel
assemblies 32 are fully off the ground. This greatly facilitates
roading of implement 10, since the caster wheels 68 of gauge wheel
assemblies 32 tend to swivel and shake when engaged with the ground
at roading speeds.
[0036] Furthermore, it will be noted that gauge wheel assemblies 32
are raised and lowered relative to main frame 12 only during those
infrequent occasions when depth adjustment is desired by
manipulating the ratchet jack 78. Consequently, the useful life of
the various movable components making up the wheel assemblies 32 is
greatly prolonged and reliability is increased. Notwithstanding the
forgoing, simultaneous depth adjustment of both gauge wheel
assemblies 32 and transport wheel assemblies 30 is accomplished by
simply manipulating the ratchet jacks 78.
[0037] The preferred forms of the invention described above are to
be used as illustration only, and should not be utilized in a
limiting sense in interpreting the scope of the present invention.
Obvious modifications to the exemplary embodiments, as herein above
set forth, could be readily made by those skilled in the art
without departing from the spirit of the present invention.
[0038] The inventor(s) hereby states their intent to rely on the
Doctrine of Equivalents to determine and assess the reasonably fair
scope of the present invention as pertains to any apparatus not
materially departing from but outside the literal scope of the
invention as set forth in the following claims.
* * * * *