Note: Descriptions are shown in the official language in which they were submitted.
i39
Grsun~-Driven Rotary_Ro~ Clean~r
This is a continuation-in-part of application Serial
No. 06/906,612 filed September 10, 1986, which was a continuation
of application Serial No. 06/705,144 filed February 27, 1985 and
now abandoned~
The present invention relates to a rotary, grou'nd
driven, row cleaner for conservation tillage farming particularly
useful in conjunction with row crop planter systems. More
specifically, in that application, it relates to a pair of
inclined pointedly toothed wheel members mounted on a row planter
unit ahead of and aligned with the opening mechanism of the
planter tc clear away surPace mulch ~nd residual vPgetation. In
more generic utilization, the toothed wheel member pairs are
mounted on tractor drawn apparatus ahead of and aligned with an
earth engaqing cutting device. The present invention is the
subject of disclosure document no. 127117, filed May 3, 1984.
Historically, farmers have relied upon conventional or
~deep~ tilling to prepare their fields for planting. In essence,
a moldboard plow, chisel plow, or other cultivating implement is
dragged over the fields after harvest of the prior crop to break
up the soil to a substantial depth, to cut and bury the residue
of the harvect, and to bring deep soil up to the surface.
~hereafter, the field must be secondarily tilled by discs or
other implements to pulverize the soil, reduce large soil clumps,
and level the field to facilitate planting operations.
Subsequently, yet another change of implements and pass over the
1~'7~i39
fields with planting apparatus is necessary to place the crop
seed in the ground. This method of farming has several
disadvantages, principally the susceptibility of cultivated
fields to erosion by wind and water run-off and the time and fuel
required for the multiple passage of the various implements over
the fields.
Within the past several ysars, the concept of
conservation tillage (also known as ~no-til7~ or ~low-till"
farmin~) ha~ emerged, whereby the fields a~e not plowed or
cultivated to any substantial degxee between crops. Instead, the
planter used opens a furrow of predetermined depth in the soil,
deposits seeds therein at a predetermined rate,;and closes the
furrow over the seeds, all in a single pass. Typically, multiple
rows are planted simultaneously by a plurality of laterally
spaced planter units mounted upon the same implement frame.
The harvesting of row crops normally leaves behind a
residue of live and dead vegetation and plant stubble (sometimes
known as nresidual mulchn), which conservation tillage farmers
typically leave in place on thQ surface after harvest. In no-
till and low-till farming of certain crops, moreover, straw or
other mulching material may conventionaily be added to the field
after harvest. In this application, the term ~mulch~ will be
used to refer to both residual mulch and added mulch. The
surface mulch serves the dual function of aiding in control of
erosion and in fertilizing the soil through decomposition. The
benefits of such a mulch cover, however, may be offset by its
~7~3~
r . ' f
disadvantages. Many shallow soils have a permanent pan at a
depth of 20 to 30 inches which makes them wet during the early
planting season. The mulch cover retards evaporation therefrom
such that soil moisture remains at unacceptably high levels past
optimum planting dates. Unless such 80ils are planted at low
rates of speed, on the order of 3~ miles per hour, the planter
unit leaves a furrow which fills with water or erodes when it
rains. In addition, surface mulch may be forced into the seed
furrow, retaining moisture at the bottom of .the furrow. The
resultant high moisture levels around the seeds retards
germination by maintaining soil temperatures too low and promotes
seed rot, thereby reducing crop yield. Matted clumps of surface
mulch ar~ not readily severed by the furrow opening me ns of
typical row crop planter units. Rather, these~ clu~ps clog the
planters or, as indicated above, may be forced into the seed
furrow as it is being opened.
The mulch cover also causes significant depth control
problems. Ideally, seeds should be planted at a uniform, optimum
depth from the surface. However, the mulch cover usually
exhibits considerable variation in thickness from row-to-row and
along each row. Thus, the planter must be adjusted to reach
adequate depth through the thickest portion of the cover. At
that adjustment, however, the seeds may be placed too deeply in
areas of thin cover. In addition, the planter heads may nbounce"
over clumps of mulch encountered by their furrow openers or depth
1;~7~'~i39
C ~ ~1
gauging means, thereby leaving seeds on or too close to the
surface.
Quite apart from planting considerations, moreover,
mulch may have an adverse impact on other farming operations.
For example, certain fertilizers, herbicides, pesticides, and
other chemicals are most effective when in immediate contact with
the soil. If such chemicals are applied by spraying or dripping,
mulch on the fields may block ~ignificant quantities from
reaching the desired direct soil contact. Mulch tends to clog or
otherwise interfere with those applicators which attempt to place
chemicals directly on or in the earth, much as mulch interferes
with planter units.
These drawbacks have led a number of growers to
dispense with mulch entirely, planting into ground essentially
cleared of everything but closely-clipped crop stubble. While
this solves the problems outlined above, the important advantages
o~ mulch cover are thereby sacrificed. The above-described
clearing operations, ~oreover, consume time and fuel. The
present invention, when used in conjunction with row crop planter
implements, removes the mulch cover from in front of the
advancing planter units, thereby permitting rapid planting with
good depth control, yet retains the cover between the rows for
erosion control and yield enhancement. The row cleaner described
and claimed herein, moreover, leaves the soil substantially
undisturbed, thereby retaining the desirable features of no-till
farming and avoiding excessive moisture levels in the soil around
-- 4 --
the planted seeds. This selective or preferential cleaning
action, whereby the mulch cover is moved away from the crop rows
without soncomitant substantial cultivation, displacement or
other disturbance of the soil along the crop rows, distinguishes
the present invention from the prior art.
The prior art reflects a number of planting implements
employing residue clearing apparatus mounted ahead of the planter
units. Examples of such prior art apparatus may be found in the
following United States patents:
No. 4,430,952 2/84 Murray
No. 4,377,797 3/83 Peterson et al
No. 4,295,532 10/81 Williams et al
No. 4,278,036 i/81 Buchele
No. 3,362,361 1/68 Morrison
Such prior art devices, however, themselves scoop, cultivate or
otherwise disturb the soil to a significant degree or are usable
only in conventionally tilled soils. In other words, their
operation may be characterized as Nindiscriminate,~ moving mulch
and soil with equal effect, rather than preferring or selecting
mulch as does the present invention.. Thus, the advantages of
conservation tillage farming in mulched fields cannot be
exploited with the referenced prior art. Moreover, the
significant soil disturbance along the seed furrows by the
referenced prior art devices permits deep penetration of rain
water, thereby retarding germination of the seeds or contributing
to erosion of the soil.
., . ~,~7~
The prior art likewise reflects a number of cultivators
employing rotating, intermeshed tines. Examples thereof may be
found in the following United States patents:
No. 3,60S,907 9/71 Schuring et al
No. 2,882,982 4/59 Hobbs
However, these prior art devices are designed and used for deep
cultivation of the soil and are thus contrary to the teachings of
the present invention.
In accordance with the present invention, each planter
unit carries a pair of pointedly toothed whëels ahead of and
aligned with the furrow opening and closing means o~ the planter.
The rctational axe3 of the toothed wheels are disposed at an
anqle relative to one another and to the line ~ travel of the
planter and are likewise inclined with respect to the vertical
plane passing through the seed furrow. ~he wheels are located at
an elevation such that the teeth penetrate the soil to a depth no
greater than that required to cause them to rotate about their
respective axes without significant disturbance of the soil. The
rotary motion thereby imparted to the toothed wheels tends to
selectively move the mulch cover aside.
It will be appreciated that clumps of mulch lying along
the intended ~urrow will be pulled apart by the rotating toothed
wheels acting in lateral opposition to one another and the
sections thereby separated will be displaced to opposite sides of
the planter unit. More heavily matted clumps, however, may not
be completely untangled and pulled apart by the toothed wheels.
6 --
1;~7~ 39
Hence, such clumps will remain in the furrower path.
This problem can be overcome by mounting the furrow
opener and the toothed wheels in close longitudinal
proximity to one another. When so arranged, the furrow
opener severs the mulch while the same i5 tensioned by
the rotating toothed wheels and, as the implement moves
on, the continuing rotation of the toothed wheels moves
the severed portions aside.
The present invention is beneficially used in
conjunction with planting units to provide selective
mulch cleaning over the crop rows and, in the instant
application, will primarily be discussed in that
setting. It is not, however, limited to such
utilization. Rather, the present invention may be
employed on a stand-alone basis or in conjunction with
chemical applicators, transplanters, grain drills, and
other farming implements wherever level bare strips of
soil are desired. When so used, an earth engaging
cutting device is disposed behind and laterally aligned
with the toothed wheels to cut the mulch pulled apart
and tensioned by the toothed wheels.
Various aspects of the invention are as follows:
In a tractor propelled implement including at least
one planter unit, each such planter unit including means
for opening a furrow in minimally tilled or untilled
soil to a predetermined depth and means for depositing
seed in said furrow, wherein the improvement comprises
means for selectively cleaning mulch from the surface of
said soil comprising:
a pair of pointedly toothed wheels journaled for
rotation about respective axes and carried by said
implement positioned with the centers of said toothed
wheels disposed above said surface on opposite sides of
an imaginary vertical plane passing through the
direction of travel of said planter unit and the teeth
of said wheels in shallow contact with the ground ahead
of said furrow opening means, whereby the forward motion
of said implement rotatably drives said toothed wheels
~'
~7~i39
about their respective axes of rotation, the rotary and
forward motion of said toothed wheels separating and
displacing the mulch laterally from the path of the
advancing furrow opening means of said planter unit in
preference to displacing said soil.
In a tractor propelled implement including at least
one planter unit, each such planter unit including means
for opening a furrow in minimally tilled or untilled
soil to a predetermined depth and means for depositing
seed in said furrow, wherein the improvement comprises
means for selectively cleaning mulch from the surface of
said soil comprising:
a pair of toothed wheels operating in lateral
opposition to one another, said toothed wheels being
journaled for rotation about respective axes and carried
by said implement positioned with the centers of said
toothed wheels above said surface on opposite sides of
an imaginary vertical plane passing through the
direction of travel of said furrow opening means and the
teeth thereof in shallow contact with the ground ahead
of said furrow opening means, whereby the forward motion
of said implement rotatably drives said toothed wheels
about their respective axes of rotation to
simultaneously pull surface mulch in laterally opposite
directions away from the path of the advancing furrow
opening means of said planter unit.
In a tractor propelled implement including at least
one planter unit, each such planter unit including means
for opening a furrow in minimally tilled or untilled
soil to a predetermined depth and means for depositing
seed in said furrow, wherein the improvement comprises
means for selectively cleaning mulch from the surface of
said soil comprising:
a pair of ground driven rotary row cleaners
disposed about an imaginary vertical plane passing
through the direction of travel of said planter unit
operating in lateral opposition to one another, each of
said row cleaners including
i~7~ 3
a hub member rotatably carried by said implement
for rotation about a predetermined axis extending
downwardly away from said imaginary vertical plane
forwardly in relation to said direction of travel, a
plurality of angularly spaced tines mounted on and
extending radially from said hub member, and means for
maintaining the angular relationship among said tines,
said row cleaners being positioned on said
implement with their respective hubs above said surface
and the outer ends of said tines in shallow contact with
the ground ahead of said furrow opening means, whereby
the forward motion of said implement rotatably drives
said tines about their respective axes of rotation to
simultaneously pull surface mulch in laterally opposite
directions away from the path of the advancing furrow
opening means of said planter unit.
Apparatus, adapted for propulsion by a tractor
along a predetermined path of travel, for selectively
cleaning mulch from the surface of minimally tilled or
untilled soil comprising:
an earth engaging cutting device,
a pair of pointedly toothed wheels in front of said
cutting device operating in lateral opposition to one
another, said toothed wheels being journaled for
rotation about respective axes and positioned with the
centers of said toothed wheels above said surface on
opposite sides of an imaginary vertical plane passing
through the direction of travel of said cutting device
and the teeth thereof in shallow contact with the ground
ahead of said cutting device, whereby the forward motion
of said apparatus rotatably drives said toothed wheels
about their respective axes of rotation, the teeth of
said wheels simultaneously pulling surface mulch in
laterally opposite directions away from the path of the
advancing cutting device.
The present invention may best be understood by
reference to the following detailed description when
7b
~ ;~7~3~'~
considered in conjunction with the accompanying drawings
in which:
FIGURE 1 is a simplified side view of a row crop
planter unit carrying the row cleaner of the present
invention;
FIGURE 2 is a diagrammatic plan view illustrating
the angular and spatial relationships among the ground
engaging
7c
.~
~tj,~39
.. . .
components of the planter unit and row cleaner of the present
invention;
FIGURE 3 is a diagrammatic front elevation view
illustrating the angular disposition of the ground engaging
components of the row cleaner of the present invention;
FIGURE 4 is a side view of one embodiment of the row
cleaning wheel employed in the present invention:
FIGURE 5 is a sectional view taken along lines 5 - 5
of FIGU~E 4;
FIGURE 6 is a diagrammatic plan view illustrating the
angular and spatial relationships among certain of the ground
engaging components of the row cleaner in a preferred embodiment
of the present invention;
FIGURE 7 is a partial simplified side view of the
planter unit's furrow opener and the row cleaner of the present
invention longitudinally arranged in accordance with the
embodiments illustrated in ~IGURE 6; --
FIGURE 8 is a partial simplified side view of anembodiment of the present invention utilizing a single disc
cutting device disposed behind a pair of toothed wheels; and
FIGURE 9 is a diagrammatic plan view illustra~ing the
angular and spatial relationships among the ground engaging
components of the row cleaner in ~he embodiment of the present
invention illustrated in FIGURE 8.
Referring now to the drawings in which the same
reference numerals designate the same elements throughout the
ceveral views, there is shown in FIGURE 1 a simplified side
elevational view of a row planter unit carrying the row cleaner
of the present invention. Since the planter unit and associated
rame are conventional, they are not illustrated in detail, the
schematic representation of FIGURE 1 being sufficient to depict
the relationship between the row cleaner of the present invention
and the key components of the planter unit. As shown in FIGURE
1, the planter unit generally designated 30 i8 mounted to a frame
generally designated 12 and including a transverse tool bar 13
rigidly connected together by means of cross members (not
illustrated in FIGURE 1 in the interests of clarity).
Preferably, tool bar 13 is constructed sf tubular steel of a
length dependent upon the number of crop rows for which the
system is designed. It will be appreciated that, while FIGURE 1
depicts a single planter unit, the frame typically carries a
plurality of planter units, one for each crop row, the planter
units being laterally spaced from one another at distances
corresponding to the desired spacing between crop rows in the
field As an illustrative example, corn or soybean rows are
typically spaced 30 or 36 inches apart.
The frame 12 may also be provided with support wheels
(again omitted from FIGURE 1 in the interests of clarity). SUCh
support wheels and their associated mounting structure are
conventional and form no part of the present invention.
As depicted in FIGURE 1, the line designated lo
represents the surface of the ground and the movement of the
system during normal operation is from right to left. The
forward end of frame 12 is provided with a bracket generally
designated 15 for mounting the frame to the lower draw points of
a conventional three-point hitch carried at the rear of a farm
tractor. In addition, one or more rear support wheels 18 may be
provided to raise the entire system for road travel. The road
wheel is mounted by means of spindle 19 to an articulated frame
including pivotally connected members 20 and 21, frame member 21
being rigidly connected to tool bar 13. Hydrau~ic cylinder 22 is
pivotally connected at one end to frame member 20 by means of
bracket 23 and pivotally connected at the opposite end to frame
member 21 by means of bracket 25. Hydraulic cylinder 22, when
extended, lowers wheel 18 in the direction indicated by arrow 27
to the surface of the ground 10 and, as hydraulic cylinder 22 is
further extended, the entire frame carrying the planter units is
raised for over the road travel. Conversely, when hydraulic
cylinder 22 is retracted, wheel 18 is raised off the ground,
allowing planter unit 30 to be supported by gauge wheels 31, as
will be more fully described hereinafter. Hydraulic fluid
pumping means and tubing for actuation o~ hydraulic cylinder 22
are conventionally carried by the pulling tractor, but are
omitted from FIGURE 1 in the interests of clarity.
Planter unit 30 is mounted behind and to tool bar 13 by
means of a separate four-bar linkage generally designated 28.
Linkage 28 accommodates variations in the surface of the ground
10 and allows planter unit 30 to generally follow the contours
-- 10 --
1~7~'~3~
.. . .
thereof. The conventional planter unit 30 has three key
operational components in contact with the ground. The angular
and spatial relationships among these components is illustrated
in FIGURE 2, in which the direction of movement is likewise from
right to left. The first such componPnt opens a furrow in the
earth to a predetermined depth without substantial disturbance of
adjacent soil and, in FIGURES 1 and 2, is depicted as a pair of
inclined discs 32 and 42. The details of the furrow opening
means form no part of the present invention, a single disc,
coulter, or other apparatus performing that function is
acceptable, the dual disc opener described herein being purely
illus~rative. A pair of laterally spaced gauge wheels 31 and 41
follow the furrow opening means and support planter unit 30 as it
is pulled across the field. Gauge wheels 31 and 41 are journaled
for rotation about axes substantially perpendicular to the
direction of travel and are substantially equidistant from and on
opposite sides of the seed furrow. It will be appreciated that
gauge wheels 31 and ~1 may rotate in substantially vertical
planes, in which case they will share a common axis of rotation,
or may rotate in planes which are inclined from the vertical, in
which case their respective axes of rotation will intersect. The
vertical relationship between the furrow opening means and the
gauge wheels 31 and 41 determine the depth of the seed furrow.
Conventionally, the furrow opening means are vertically fixed in
position and gauge wheels 31 and 41 raised or lowered by means
(not shown) to regulate the seed furrow depth. However, it will
1;~7'~i39
be appreciated that depth regulation may be likewise obtained by
vertically fixing the axes of rotation of gauge wheels 3 and 41
and providing for vertical adjustment of the furrow opening means
or by providing for vertical adjustment of both the furrow
opening means and gauge wheels 31 and 41. In any event, the
depth of the furrow will be the distance which the furrow opening
means projects below the rims of gauge wheels 31 and 41.
Trailing behind gauge wheels 31 and ~1 are furrow
closing means, depicted in the figures as a.pair of inclined
pinch wheels 33 and 43. Once again, this component of planter
unit 30 is conventional and the embodiment illustrated herein is
merely illustrative. A single wheel or other conventional furrow
closing means may readily be substituted therefor without
departing from the present invention.
Planter unit 30 includes seed storage hopper 34, the
latter being provided with a conventional metering mechanism (not
shown) to regulate the flow of seed from hopper 3~. Planter unit
30 may also include a pesticide/fertilizer storage hopper 35 with
associated metering mechanism (not shown~ to regulate the flow of
pesticide or fertilizer from hopper 35.
The operation of planter unit 30 is well known in the
art. As the system is moved a~ross the field by a tractor (not
shown) to which moun~ing bracket lS has been attached, discs 32
and 42 penetrate the earth along a moving zone of contact,
thereby opening a narrow furrow. The metering mechanism (not
shown) associated with hopper 34 dispenses seed into a tube (not
1~.7~i;39
shown) at a rate bearing a predetermined relationship to the
travel of the planter unit 30. The outlet of the tube is located
between gauge wheels 31 and 41, so that the metered seed from
hopper 34 is deposited in the furrow. If pesticide or fertilizer
is stored in hopper 35, it may likewise be metered and deposited
via another tube into the furrow between gauge wheels 31 and 41.
Trailing pinch wheels 33 and 43 in turn close the furrow over the
seed.
The foregoing describes the idealized operation of a
planter unit without the row cleaner of the present invention,
assuming operation over bare earth. As noted earlier in this
application, however, significant advantages accrue from a mulch
cover over the field. But, as also outlined above, in a
conventional planter unit the mulch may be forced into the furrow
by discs 32 and 42 or may cause gauge wheels 31 and 41 to raise
above ground level, thereby reducing the depth of the furrow.
The present invention, comprising rotating toothed wheels 50 and
60 mounted ahead of each planter unit, reliably clears the mulch
cover from the path of the planter unit 30 such that the furrow
opening means, gauge wheels, and furrow closing means operate
over essentially bare earth while the desirable mulch cover is
maintained between rows.
As illustrated in FIGURES 2 and 3, toothed row cleaning
wheels 50 and 60 are independently journaled for rotation about
inclined, intersecting axes. In particular, row cleaning wheel
50 rotates about axis 52 and row cleaning wheel 60 rotates about
- 13 -
1~7X~
axis 62. The details of means for rotatably mounting cleaning
wheels 50 and 60 to planter unit 30 are not a part of the present
invention and may, for example, be those described in United
States Patent No. 4,425,973 issued on January 17, 1984, in the
name of Donald E. Wiliiams and Forest E. Robertson. It will be
observed that the axes of rotation 52 and 62 intersect at a point
substantially within an imaginary vertical plane, indicated in
FIGURES 2 and 3 by broken line 70 passing midway between gauge
wheels 31 and 41, said point of intersection being behind and
above (as viewed from the side as in FIGURE i) the respective
centers of rotation of wheel members 50 and 60. Thus, the
compound angular relationship between each axis of rotation and
that imaginary vertical plane may be defined ~y its vertical
component 0 and its horizontal component B. The compound angular
relationship above described may also be defined by the vertical
and horizontal components of the angle between each plane of
rotation of cleaning wheels 50 and 60 and the aforementioned
imaginary vertical plane. Since the axes of rotation are, by
definition, perpendicular to the plane of rotation and the
imaginary vertical plane is the complement of 0 and the
horizontal component of that angle is thé complement of B.
Row cleaning wheels 50 and 60 ara mounted to planter
unit 30 at a height such that the teeth thereof penetrate the
soil to a depth sufficient for the forward motion of the system
to cause the wheels to rotate, ye~ not so deep as to
substantially cultivate, displace, or otherwise disturb the soil.
~ . ~
That rotation brings the teeth of cleaning wheels 50 and 60
successively into and out of engagement with the ground along a
moving contact zone. As cleaning wheels 50 and 60 rotate, the
teeth at their lower peripheries engage the strands of mulch at
and adjacent the earth's surface, imparting forces whose
respective lateral components are directed away from the furrower
path as the implement advances. Toothed cleaning wheels 50 and
60 thus work in opposition to one another, tending to pull the
mulch in opposite directions at the same time . By pointing the
ends of the teeth, the tooth cross section in contact with the
earth is reduced and the teeth loosen and tear the roots of
subsurface residual vegetation so that the sam~e may be more
easily swept aside. The rotating teeth of the cleaning wheels 50
and 60, directly ground-driven and configured as they are like
the tines of a rake or fork, have greater motive effect on the
mulch than they do on the underlying soil. Ih other words, the
rotating toothed wheels displace the mulch in preference to
displacing the soil. Accordingly, shallow penetratiDn provides
virtually complete mulch removal. The rotation of the row
cleaning wheelæ thus selectively moves the mulch cover aside as
the system traverses the field, leaving the conservation tilled
soil substantially undisturbed. The minimal effects of the
shallow soil disturbance caused by the cleaning wheels 50 and 60
are further reduced by the action of the pinch wheels 33 and 43
or other conventional furrow closing means as they close the seed
furrow and tamp the soil. As outlined above, ~his contrasts with
- 15 -
;3~3
the indiscriminate earth-working action of prior art row clearing
apparatus which results in undesirable soil erosion, higher fuel
consumption, and slower planting rates.
FIGURES 4 and 5 illustrate one embodiment of the row
cleaning wheels which may be readily fabricated from materials
generally available to the average farmer. As shown therein, row
cleaning wheel 50 is comprised of hub member 53 carrying bearing
56, a plurality of pointed spoke members 55, rim members 54 and
s8, and washer-shaped backing plate member 57. Bearing 56 is
mounted for rotation about axis 52 and~ although illustrated as a
sleeve bearing, may be of any conventional construction, such as
roller or ball bearing. Each of the spoke members 55 may be
fabricated from mild steel bar stock by cutting to length and
grinding one end to a point. Although FIGURE 5 depicts a sharply
pointed asymmetric end, it will be appreciated that a blunter or
more symmetric point configuration may be used. In a preferred
embodiment ~ x ~ n bar stock is used. The inner ends of spoke
members 55 are disposed, generally equidistantly from one another
around a circle centered at axis of rotation 52, between the
flanged portion of hub member 53 and backing plate member 57 and
attached thereto, by rivets, screws, or other conventional
fasteners (not shown). Spoke members 55 are likewise sandwiched,
near their outer ends, between and affixed to rims 54 and 58,
generally equally spaced about the circumference thereof. Thus,
hub member 53 and backing member 57 support the spoked members 55
at their inner ends for rotation about axis 52 and rim members 54
- 16 -
~L~7~
.. .
and S3 support and maintain the angular relationships between the
spoke members 55 near their pointed outer ends. It will be
appreciated that one or both rim members 54 and 58 or backing
member 57 ~ay be omitted if the remaining structure is
suf f iciently strong to support spoked members ss.
Surface mulch may include clumps or masses of tangled
vegetable matter. Clumps lying to one side or the other in
relation to the path of the furrow opener encountered by one
toothed row cleaner wheel of the present invention are moved
further away from the path -- clumps on the left are displaced to
the left while clumps on the the right are displaced to the
right. Thus, each of the rotating wheels act with a lateral
force upon the mulch, a lateral force directed away from the
planter unit's path of travel.
When, however, both rotating toothed wheels of the
present invention encounter the same mass of tangled vegetable
material along the path followed by the furrow opener, the left
wheel tends to move that portion of the mass lying to the left of
the furrow path aside to the left while the right wheel tends to
move the other portion of the mass aside to the right. The
coaction of the rotating wheels thereby applies forces to the
mass extending laterally in opposite directions away from the
furrow path. The strands of vegetable material forming the mass
along the furrow path are thereby tensioned and pulled apart by
the toothed wheels as they rotate. Thus, the mass is untangled
by the coaction of the advancing wheel pair, much as a pile of
- 17 -
~7;~
spaghetti would be separated by two forks working in opposite
directions. Indeed, the denser and more entangled the mulch is,
the more effectively it can be displaced by the rotating too~hed
wheels.
Heavily matted clumps, however, may not be completely
separated by the action of the toothed wheels alone. Instead,
longer strands of vegetable material may remain entangled with
both portions of the matted clump. Under those conditions, the
coaction of the rotating toothed wheels has tensioned the
connecting stra~ds laterally of the planter's path of travel and
will continue to do so as the planter unit advances. When so
held apart in tension, the connecting strands will be cut by the
front edge of the furrow opener. Thus, although the pair of
rotating toothed wheels may not have completely untangled the
matted clump, thair coaction pulls the connecting strands in
opposite directions so that the advancing furrow opener cleanly
cuts the tensioned strands and the rotating wheels thereafter
sweep the then severed clump portions aside.
~ he foregoing describes the present invention used in
conjunction with conventional row crop planters, wherein the
inclined discs which open the seed furrow also function to cut
the strands of mulch tensioned by the toothed wheels. It is
readily apparent that a single disc or other conventional furrow
opener would likewise perform that mulch severing function in
much the same manner. As noted above, however, the present
invention is not limited to such use. Indeed, grain drills,
- 18 -
1;~7;~3~
.. .. ~
transplanters, and other implements benefiting from operation
over level bare strips of substantially untilled earth are prime
candidate~ for the cleaning wheels of the present invention, as
are high pressure or dribble fertilizer applicators, anhydrous
ammonia applicators, or other apparatus for application of
chemicals directly to the soil. Such other equipment, however,
typically does not slice into the ground like the furrow opener
of a row crop planter, Accordingly, i~ the cleaning wheels of
the present invention are mounted on such other equipment without
further modification, the clumps of mulch pulled apart and held
in tension by the toothed wheels will not be severed as the
apparatus is moved across the field. In order ~o provide that
mulch severing action, therefore, an earth engaging cutting
device is mounted in essentially the same lateral and
longitudinal relation to the toothed wheels as the above
described furrow opener characteristic of row crop planter units.
Such a device may be, for example, as simple as a single disc
journaled for rotation about a horizontal axis perpendicular to
the direction of travel. Since such a cutting device functions
only to sever the tensioned mulch, it need not enter the soil to
the same depth as does a furrow opener. Analogously with the
toothed row cleaning wheels themselves, the cutting device should
penetrate the soil no deeper than required by its mulch severing
function. The surface of the earth acts much as a cutting board
or other support against which the edge of the disc operates to
sever the mulch. Satisfactory results for a single disc rotating
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~7X~3~t
cutter may be obtained at depths about the same as those to which
the toothed cleaning wheels penetrate.
The toothed cleaning wheel pairs of the present
invention need not be used concurrently with any other implement,
but have utility for independent operation. Thus, for example,
in wet early planting season conditions, the cleaning wheels of
the present invention may be used on a stand-alone basis to clear
strips of mulch from the intended crop rows a few days before
planting. As the s-~n warms these cleared strips, moisture will
evaporate from the top layer of the soil (the surface and
adjacent underlying portions to a depth of about 1 inch) to
present the furrow opener with a drier surface on which to
operate. Likewise, such cleared strips make fo~ more effective
pre-planting application of chemicals directly to the soil or
more effective post-cleaning USQ of grain drills, transplanters,
or other implements. As described above! such stand-alone
applications require an earth engaging cutting device mounted in
essentially the sa~e lateral and longitudinal relation to the
toothed wheels as the above described furrow opener
characteristic of row crop planter units.
The furrow opener (or cutting disc) and toothed wheels
should be located longitudinally close together, consistent with
accomplishing the above-described tensioning function in the
mulch on the particular field being cleaned. To adapt the unit
for differing mulch conditions, fore-and-aft adjustment may be
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1~7~j39
provided for the furrower ~or cutting disc) mounting or the
cleaning wheel mounting, or both.
FIGURE 6 diagrammatically illustrates the desired
proximate longitudinal relationship between the toothed wheels 50
and 60 and the furrow opener discs 32 and 42. Note that FIGURE 7
depicts in stylized fashion toothed wheel 50 and furrow opener
disc 32; in the interests of clarity, other components and
supporting structure have been omitted from this view.
Optimally, the leading edge 39 of disc 32 enters the ground at
surface 10 at or ahead of (as viewed from the side as in FIGURE
7) the longitudinal position of the trailing edge S9 of the
toothed wheel 50 as the latter lo es contact wlth the ground.
Thus, in a preferred embodiment of the present invention, the
furrow is continususly opened at a point ahead of the rotating
toothed wheels' points of disengagement from the ground as the
planter unit advances along the row. As t~e opener slices a
furrow in the earth, it also slices through any strands of
partially untangled mulch pulled apart by the toothed wheel pair.
If, contrary to the above teaching, the furrow opener's
leading edge is located behind the toothed wheel's trailing edge,
there exists the possibility that the toothed wheels may carry
the still somewhat tangled clumps around as they rotate, thereby
clogging the cleaner unit. In addition, even if the partially
untangled clumps instead drop to the ground from the trailing
edges of the toothed wheels, the laterally opposing forces will
no longer be applied to the fallen clumps. When tension is
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1;~7~3~3
thereby released before the arrival of the furrow opener, the
connecting strands may be forced into the seed furrow by the
advancing furrow opener, rather than being cleanly cut by the
urrow opener at the surface and swept aside by the row cleaning
wheels. Accordingly, the close mounting depicted in FIGURES 6
and 7 improves performance in fields covered with heavily matted
clumps of mulch.
An embodiment of the present invention used as a stand-
alone row cleaner or utilized in conjuncti~n with chemical
applicators or other non-planter equipment is depicted in
simplified partial side elevation as FIGURE 8. This embodiment
is generally similar to the planter-mounted equ1pment shown in
FIGURE 1, but differs therefrom in that the seed/fertilizer
storage hoppers, metering and delivery mechanisms are absent, as
are the ~urrow closinq wheels, and that a single cutting disc 36
is substituted for the furrow opener. As with the aforementioned
planter-mounted equipment, the row cleaning unit is mounted
behind and to a tool bar through a four-bar linkage or other
conventional means ~not shown in FIGURE 8) to accommodate the
contour of the ground 10. Each row cleaning unit comprises a
pair of toothed cleaning wheels rotatably mounted via
conventional mean~ for carriage at a predetermined height above
the surface of the ground. Following the toothed wheel pair 50-
60 is a single disc cutter 36 journaled for rotation about a
horizontal axis perpendicular to the direction of travel, said
axis being indicated by reference number 38 in FIGURE 9. Gauge
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1~7~ 3
wheels 31 and 41 support the row cleaning assembly. It will be
appreoiated that the components of each row cleaner -- toothed
wheel pair 50-60, disc cutter 36, and gauge wheels 31 and 41 --
may be mounted to a subframe (not shown in FIGURE 8) extending
from the four-bar linkage or other implement mounting means (also
not shown in FIGURE 8 ) . As shown in FIGURE 8, the disc cutter 36
penetrates the soil to a depth approximately equal to or less
than the maximum depth at which the teeth of toothed wheels 50
and 60 operate. Note that FIGURE 8 depicts in stylized fashion
toothed wheel 50 and cutting disc 36; in the interests of
clarity, other components and supporting structure have been
omitted from this view.
FIGURE 9 diagrammatically illustratès the angular
relationships in a horizontal plane between tke toothed wheels in
each pair, as well as the spatial relationship among the ground
engaging components of this embodiment of the present invention.
Toothed wheels 50 and 60 are disposed generally symmetrically
about an imaginary vertical plane 70 extending through the path
o~ travel followed by cutting disc 36. As with the dual disc
furrow opener, the leading edge of disc 36 optimally enters the
ground at surface 10 at or ahead of (as viewed from the side as
in FIGURE 8) the longitudinal position of the trailing edge 59 of
the toothed wheel 50 as the latter loses contact with the ground.
Accordingly, as the row cleaning assembly traverses the ground,
the toothed wheels 50 and 60 are rotatably driven to work in
lateral opposition to one another, separating and raking mulch
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~7;~ti3~
.~
lying in a strip along the path of travel in laterally opposite
directions away therefrom. Cutting disc 36 is likewise rotatably
driven by the movement of the apparatus across the field to
provide a rolling slicing action adjacent the initial point of
contact 59 with ground surface 10 where it severs strands of
mulch laterally tensioned by toothed wheels 50 and 60. Gauge
wheels ~1 and 41 trail behind cutting disc 36 and are disposed
substantially symetrically about the aforesaid imaginary vertical
plane 70. The angular relationship, in a vertical plane
perpendicular to the direction of travel, bëtween the toothed
wheels in each pair is illustrated in FIGURE 3.
In the illustrated embodiments, cleaning wheels 50 and
60 are angularly disposed and dimensioned so as to intersect,
with teeth intermeshed, above the surface of the ground 10 at a
height less than one-half of their root diameter. It is believed
that the intermeshing of the teeth prevents mulch from clinging
to the teeth. In a preferred embodiment, row clearing wheels 50
and 60 each have an outer diameter of 16 inches with 16 equally
spaced li inch deep teeth and are each journaled for rotation
about an axis disposed at angle 0 of 75 from the vertical and
angle ~ of 60- from the path of travel of the planter unit.
Using the alternate definition described above, the respective
planes of rotation of row cleaning wheels 50 and 60 are each
disposed at 15- from the vertical and 30- from the path of travel
of the planter unit.
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1~7c:~i39
It must be recognized that the above-ref renced
preferred e~bodiment is only one within a wide range of
variables. Thus, the diameter of cleaning wheels 50 and 60,
which may be limited by the equipment dimensions and
configuration, may range from about 10 to 20 inches and their
tooth depths may range from about ~ inch to 3 inches. Likewise,
the cleaning wheels may be inclined such that the vertical
component of the angle at which their axes of rotation intersact
(twice 0) ranges between about 120- and 160- and the horizontal
component of the angle at which their axes of rotation intersect
(twice B) ranges between about 90- and 150-.
The details of the means for mounting the row cleaning
wheel assemblies to a subframe or the planter unit frame are not
a part of the present invention and may, for example, be as
described in the above-cited Williams and Robertson patent. The
optimum depth to which the toothed wheels penetrate the earth
will depend upon the particular conditions encountered in the
field. In general, the degree of penetration should be set at
the minimum necessary to provide satisfactory mulch clearin~.
Under conditions which the conservation tillage farmer may
reasonably expect to find, the row clearing wheel teeth in the
preferred embodiment referenced above penetrate the soil to a
depth ranging approximately from between 3 inch to 1~ inches. It
will be appreciated that, where a planter unit which carries the
row cleaner of the present invention regulates planting depth by
vertically adjusting the gauge wheels, the row cleaner must
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7;~ i39
likewise be carried so as to be vertically adjustable in like
amounts, thereby regulating the depth of penetration of the teeth
carried by the row clearing wheels. The abové-referenced
Williams and Robertson patent illustrates one such vertically-
adjustable mounting structure. On the other hand, if a carrying
planter unit employs vertically fixed gauge wheels, with
vertically adjustable furrow opening means, the row cleaner of
the present invention need not be mounted to permit vertical
adjustment. The same mounting considerations are applicable to
stand~alone row cleaners of the present invention, as well as
those carried by non-planter equipment.
Having thus described in detail a preferred embodiment
of the invention, persons skilled in the art will be able to
modify certain of the structure illustrated and described herein
and substitute therefor equivalent elements while continuing to
practice the principles of the invention. Therefore, it is
intended that any and all such modifications and substitutions be
covered and they are embraced within the scope and spirit of the
appended claims.
