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Description  |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an agricultural implement having a
plurality of soil packer units which are each positioned ahead of a
respective, independent harrow assembly.
2. Description of the Prior Art
Compaction of soil around newly planted seed has long been known to
substantially increase crop yield. In the past, soil compaction has
sometimes been provided by a number of relatively heavy packing wheels
mounted on a cultivator, but unfortunately the packing wheels may cause a
substantial amount of stress to be imposed on frame members of the
cultivator, and the wheels may also present problems during transport.
Certain cultivators have springs to apply force to the packer wheels, but
uneven depth control of the cultivator may occur when the weight of the
cultivator is less than the forces imposed on the packer wheels.
In recent times, increased interest has been directed toward the concept of
soil compaction by means of a series of coil packers coupled to the
trailing ends of harrow assemblies. Examples of these types of harrow
packer units are shown in U.S. Pat. No. 4,418,762 and Canadian Pat. Nos.
838,417, 871,991, 1,081,021, 1,099,566, and 1,212,569. The coil packer
creates a herringbone pattern on the ground which, according to some, is
useful for reducing wind and water erosion.
However, certain problems have been observed in connection with the
herringbone pattern left in the soil after use of a harrow packer unit. In
particular, water uptake by the soil is decreased once the sidewalls of
the herringbone packer tracks become hard and crusted, and evaporation
losses are increased upon formation of puddles in the tracks. Existing
soil moisture may be readily lost due to capillary action within the
crusted, packed soil of the tracks which is directly exposed to the
atmosphere. Also, the wave-like herringbone pattern increases the total
exposed surface area of the field, which causes a corresponding increase
in total evaporation losses. Moreover, water runoff is more likely to
occur in packed grooves than might occur, for instance, in loose soil.
Other problems that have been observed with regard to harrow packer units
include the tendency for the coil packers to reintroduce weeds into the
ground that have previously been uprooted during airseeding or during
harrowing, thereby encouraging the weeds to continue to grow and compete
with the crop. In addition, harrow packer units tend to leave finely
crushed soil on the top surface of the ground where it is susceptible to
erosion by wind and water.
In some harrow packer units, coil packers are arranged in staggered
disposition relative to the normal direction of travel of the implement.
In this manner, the width of each coil packer can be increased in an
attempt to eliminate missed areas of the ground not subjected to the
forces of the coil. However, during relatively sharp turns, some areas of
the ground may be left untouched due to the large distance between the
coil packers and the axis of turning movement of the implement. Also, such
construction increases the cost of the coil packers in proportion to the
increased width of the same.
Another problem associated with harrow packer units is due to the
relatively complex and expensive mechanism that is often provided for
folding the unit into and out of an orientation for transport. In these
devices, arms supporting the harrow assemblies are fixed to a transversely
extending structural frame member which is selectively pivotable about an
axis parallel to its longitudinal axis for raising the unit toward a
folded orientation. However, the relatively heavy coils are pivotally
coupled by means of an elongated hitch to the trailing ends of the harrow
support arms, and therefore relatively stiff structural members and large
hydraulic piston and cylinder assemblies are needed for developing
sufficient torque to overcome the moment presented by the packer coils and
raising the arms toward a vertical orientation. In addition, the coil
packers of the folded unit, being supported solely on one side of the
harrow by the now overlying pivotal connection, are free to sway and thus
present a somewhat unstable arrangement during transport of the unit.
Furthermore, unfolding of the aforementioned harrow packing units requires
skill and closely timed operator coordination since the unit must be
advanced slowly at a creep speed as the packers are lowered to the ground.
Other problems which are encountered in harrow packer units of this type
include the tendency of the packers and harrow sections to bind during
turns while the unit is in its folded, transport orientation which may
lead to serious damage to the tines.
SUMMARY OF THE INVENTION
Our present invention overcomes the problems noted above by provision of a
packer harrow implement having a number of packer units directly coupled
to a transversely extending frame member or tool bar, with harrow sections
carried behind the packer units by elongated, arched carrier arms
extending over the packer units. Each of the packer units is connected by
means of short, pivotal links to the frame member for up and down shifting
movement in substantial independence of the vertical movement of the
trailing harrow sections.
A number of important benefits are realized by use of the present
invention. By mounting the coil packers ahead of the harrow sections,
clumps and clods of soil as well as trash are left on the top of the
ground, thereby functioning as a barrier to prevent moisture loss through
capillary action. The clumps, clods, and trash reduce wind and water
erosion, and the trash cover enhances moisture intake into the soil from
rain and also facilitates subsequent retention of the moisture. Weeds
pulled from the soil by the harrow tines are left on the ground surface to
die instead of being reintroduced into the ground for additional growth as
is observed with conventional apparatus.
Advantageously, the location of the relatively heavy packer units, in
close, proximal relationship to the tool bar or frame member, greatly
reduces the moment developed during pivotal movement of the frame member
about an axis parallel to its longitudinal axis to raise the packer units
and harrow sections toward an upright orientation for transport. The
moment developed is considerably less than the moment which occurs during
lifting of prior art harrow packer implements having the packer coils or
drums located behind the harrow sections and at some distance from the
pivotal, transverse structural frame member or tool bar. As such, the size
and strength of the structural members as well as the hydraulic piston and
cylinder assembly of the present invention can be substantially smaller
than heretofore realized, thereby affording a significant cost savings.
In preferred embodiments of the invention, the short links interconnecting
the packer units and the frame members are movable toward a position of
firm, resting contact with the frame member when the latter is pivoted for
raising the packer units and harrow sections toward their upright,
transport orientation. As a result, the weight of the packer units when
lifted toward a transport orientation causes the units to be retained in
secure engagement with the frame mebers without oscillating or moving
laterally as the implement is transported at relatively fast speed. In
addition, the elevation of the packer units when in the transport mode
remains relatively close to the ground so that the center of gravity of
the raised implement is significantly lower than in prior art structures,
thereby enhancing the stability of the assembly during on or off the road
travel.
Moreover, the implement constructed in accordance with the invention may be
readily folded or unfolded out of its transport orientation without
interference or tangling between the packer units and the harrow sections,
inasmuch as the harrow sections are at all times kept out of contact with
the packer units. During unfolding, the implement need not be advanced at
a creep speed as is the case with foldable harrow packer implements which
are articulated between the harrows and the trailing packers. Moreover,
since the harrow sections of the present invention are located at a
distance from the pivotal frame member, the harrow sections may be easily
raised from the ground when plugged without interrupting the advancement
of the implement or raising the packer units away from the earth.
Another important aspect of the present invention relates to the preferred
construction of the packer units which are in the form of a generally
helical coil. In particular, end regions of each packer coil extend in
directions somewhat different than the remaining, major extent of the coil
and terminate at a location closely adjacent a portion of a neighboring
convolution, thereby shortening the overall width of the packer unit. As a
result, the end-to-end clearance between adjacent packer units may be
decreased so that satisfactory soil compaction is provided across the
entire width of the implement without the necessity of, for instance,
staggering the packer units to obtain full coverage as is the case with
certain conventional harrow packer implements.
The coil packers, being located closely adjacent the transverse tool bars
or frame members, offer excellent clearance in turns. The coil packers are
thereby also disposed at a relatively short distance to any axis about
which the implement is turned, thus substantially eliminating the presense
of missed regions of the soil not subjected to compaction. The packers and
harrow sections do not bind against each other and damage the tines.
Moreover, the two coil packers which are located adjacent opposite
transverse ends of the implement are preferably somewhat shorter than the
remaining coil packers, so that the two endmost harrow sections cover the
tracks left by the field tires while the tires function to provide soil
compaction in regions outboard of the packer units.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a packer harrow implement constructed in
accordance with the invention;
FIG. 2 is a fragmentary, enlarged, side elevational view of the implement
taken along line 2--2 of FIG. 1;
FIG. 3 is a view somewhat similar to FIG. 2 except that transversely
extending tool bars or frame members of the implement have been pivoted to
raise the packer unit and harrow sections from the ground;
FIG. 4 is a plan view of the implement shown in FIG. 1 except that the
harrow sections and packer units have been raised and then folded to an
orientation for transport;
FIG. 5 is an enlarged, fragmentary plan view of one of the frame members
and packer units;
FIG. 6 is a fragmentary, enlarged, side cross-sectional view of the frame
member and packer unit shown in FIG. 5 along with a portion of an
overlying, arched carrier arm for a trailing harrow section;
FIG. 7 is an enlarged, fragmentary plan view in partial section of one of
the links for the coil packer units shown in FIGS. 1-6 which is connected
to a ball and socket coupling detachably secured to one of the frame
members; and
FIG. 8 is an enlarged, fragmentary, side elevational view with parts broken
away in section of a pivotal interconnection between a wing frame member
and a main frame member of the implement depicted in FIGS. 1-7.
DETAILED DESCRIPTION OF THE DRAWINGS
An agricultural implement, broadly designated by the numeral 10 in FIGS.
1-8, has hitch structure 12 with a forward end portion 14 that is depicted
in FIGS. 1, 3, and 4. The hitch structure 12 is supported by four parallel
wheels 16, and the forward end portion 14 of the hitch structure 12 is
adapted for connection with a towing vehicle (not shown) that is movable
in an advancement direction over the ground and along a path of travel.
As best illustrated in FIG. 1, the implement 10 has a main frame member 18
which is connected on each end by pivotal couplings 20 to an inboard end
of a respective wing frame 22. A center frame member 24 is fixed to the
main frame member 18 by means of bars 26 that can be observed by reference
to FIGS. 2 and 3.
Referring to FIGS. 1-3 and 8, a pair of bracket assemblies 28 are securely
connected to opposite end portions of the main frame member 18 and are
each coupled by means of a pivot 30 (FIGS. 2 and 3) to a trailing end of
the hitch structure 12. An outermost portion of each bracket assembly 28
is pivotally secured to one end of a hydraulically powered piston and
cylinder assembly 32, the remaining, forward ends of which are pivotally
coupled to upstanding legs 34 (FIGS. 2 and 3) fixed to side members of the
hitch structure 12.
By comparison of FIGS. 2 and 3, it can be seen that simultaneous retraction
of the pistons of piston and cylinder assemblies 32 lifts the main frame
member 18 as well as wing frame members 22 and center frame member 24 for
swinging movement about a horizotal axis coincident with pivots 30. Once
the frame members 18, 22, 24 have been shifted from their use orientation
shown in FIG. 2 to their transport orientation illustrated in FIG. 3, a
pin connection (not shown) may be inserted through an aperture 36 in the
bracket assemblies 28 as well as a corresponding aperture in an upstanding
leg 38 affixed to structure 12 in order to releasably lock the members 18,
22, and 24 in their transport orientation.
Implement 10 further includes a number of soil packer units 40 which are
disposed directly behind a respective one of the frame members 22, 24.
Preferably, each of the packer units 40 is comprised of a generally
helically shaped coil packer 42 as is shown in FIGS. 1 and 5, although
other types of packer units such as crowfoot packers may also be employed.
Each of the coils 42 is fixed on opposite ends to bar-like supports 44
(see, in this regard, FIGS. 5 and 6) which, in turn, are securely
connected to a shaft 46 disposed along the central, longitudinal axis of
coil 42. End sections of the shaft 46 are received in respective bearings
48 that are connected to trailing ends of short links 50, the forward ends
of which are fixed to a swivel or ball and socket connector 52.
The ball and socket connector 52 is better shown in FIG. 7, where it can be
observed that a pin 54 extends through a central bore in the connector 52
as well as aligned holes in opposed legs of a U-shaped bracket 56 that is
fixed to a side of one of the square-in-cross section wing frame members
22, although a similar arrangement is employed for coupling the connectors
52 of the central coils 42 to the center frame member 24. The pin 54 is
releasably retained in place by means of a hairclip 58, so that the packer
units 40 may be readily detached from the implement 10 when desired.
A number of spaced, parallel carrier arms 60 are securely coupled to frame
members 22, 24 and extend rearwardly relative to the advancement direction
of the hitch structure 12 in parallel relation to the path of travel of
the implement 10 over the ground. Each of the arms 60 has a raised or
arched section 62 that curves over and around the coils 42 therebeneath. A
relatively short, elongated leg 64 is fixed to each of the arms 60
directly behind the arched section 62 in generally transverse relation to
the direction of extension of arms 60.
Each adjacent pair of the carrier arms 60 supports a leveling device for
smoothing the soil. In the particular embodiment illustrated in the
drawings, each leveling device is in the form of a harrow section 66
coupled to the carrier arms 60 by means of flexible strap means or chains
68, 70. Chains 68 interconnect a mid-region of each harrow section 66 and
an end portion of each carrier arm 60, while chains 70 interconnect a
forward region of each harrow section 66 and lower regions of legs 64.
Viewing FIGS. 1-3, each of the harrow assemblies or sections 66 includes a
rectangular framework 72 having a transversely extending front element 74
(FIG. 1). Four parallel, spaced carrier pipes 76 are fixed to the
underside of framework 72, and each pipe 76 carries a number of slender,
yieldable spring tines 78 (FIGS. 2 and 3).
When the implement 10 is in its use orientation as shown in FIGS. 1 and 2,
and 5-8, the chains 68 are slack and the front chains 70 are operable to
pull the sections 66 in a forwardly direction. However, as the frame
members 22, 24 are shifted about pivot 30 by means of piston and cylinder
assemblies 32 to the transport orientation as shown in FIG. 3, chains 68
function to limit the extent of the downwardly shifting movement of the
harrow sections 66 and retain the same in proximal relation to arms 60.
A better understanding of the couplings 20 interconnecting the wing frame
members 22 and the main frame member 18 may be obtained by reference to
FIG. 8. As shown, the coupling 20 includes a pivotal connection 80 which
allows independent, up and down swinging movement of the respective wing
frame 22 relative to the main frame member 18 when the implement 10 is in
its field or use orientation as is shown in FIG. 1. Also, once the piston
and cylinder assemblies 32 have been retracted to pivot the frame members
18, 22, 24 to their transport orientation as is shown in FIG. 3, the two
wing frame members 22 are swingable about the now vertically oriented
pivotal connection 80 in a rearwardly direction and toward the
configuration as shown in FIG. 4 so that the implement 10 presents a
relatively narrow profile for transport. In this orientation, a second
pivotal connection 82 of coupling 20, disposed in offset, perpendicular
relation to pivotal connection 80, enables up and down swinging movement
of the wing frame members 22 relative to the main frame member 18 and the
hitch structure 12 as a pair of transport wheels 84 roll over the ground.
As illustrated in FIG. 1, a pair of wire cables 86 are fixed to the front
end of respective, elongated bars 88 that are each coupled to a
corresponding side of the hitch structure 12 by means of a pivotal joint
90. The remaining end of each cable 86 is connected to one of the wing
frame members 22 in order to retain the latter in alignment with the main
frame member 18 as the implement 10 is advanced over the ground in its use
orientation. A latch 92, mounted on the forward end portion 14 of hitch
structure 12, is releasable to enable the bars 88 to swing about
respective joints 90 for allowing the wing frame members 22 to be shifted
rearwardly toward their folded, transport orientation shown in FIG. 4.
Each of the bars 88 is biased downwardly toward their orientation as shown
in FIG. 1 by means of a spring (not illustrated) so that the cables 86 do
not become entangled with remaining components of the implement 10 during
folding or unfolding of the latter.
It can now be appreciated that during use of the imlement 10, the short,
pivotal links 50 directly interconnecting the coil packers 42 and the
frame members 22, 24 are shiftable up and down in substantial independence
of the movement of the carrier arms 60. Moreover, the ball and socket
connectors 62 function to enable the orientation of the packer coils 42,
and particularly the central axis of the coils 42, to tilt in either
direction slightly from horizontal in order to follow the contours of the
ground without affecting the position or orientation of the respective
trailing harrow section 66. The arched section 62 of the carrier arms 60
provides sufficient clearance for avoiding contact with the coils 42
therebelow as the latter ride in complete freedom over large stones or
other obstacles in the field without damage to the body of the coils 42.
Each of the coils 42 rolls smoothly over the ground during advancement of
the implement 10 to roll and pack the soil and thereby enable the harrow
sections 66 to travel along a smoother path. In addition, the trailing
harrow section 66 smoothes and levels the ground, pulls up weeds and
leaves the trash and coarse particles on the ground surface to thereby
reduce wind and water erosion and enhance soil moisture retention, while
also leaving the weeds on top of the ground to die.
Upon completion of the work operation, the piston and cylinder assemblies
32 are retracted to simultaneously raise the frame members 22, 24 and the
associated packer units 40 and harrow sections 66 toward their upright,
transport orientation as shown in FIG. 3. At the same time, a portion 94
(FIG. 6) of each of the packer unit links 50 moves toward a position of
firm, resting contact with a stop means or wall surface 96 (FIG. 7) which
is formed as part of the associated bracket 56. Therefore, the relatively
heavy coil packers 42, which may, for example, weigh as much as a 150
pounds per lineal foot, are securely supported by the respective frame
member 22, 24 when lifted to a transport orientation and do not shift or
bounce during relatively high speed road transport of implement 10.
Furthermore, it can now be understood that the disposition of the packer
coils 42, in forward relation to the harrow sections 66, is highly
advantageous in that the mass of the packer coils 42 is retained at all
times in close, proximal relation to the supporting frame members 22, 24.
Thus, the size of the piston and cylinder assemblies 32 and strength and
stiffness of the structural members such as members 22, 24 is smaller than
what would be otherwise be necessary. The swinging movement of the links
50 toward the position shown in FIG. 3 in contact with the wall surfaces
96 lowers the center of gravity of the implement 10 somewhat in
disposition closer to the ground as well as the pivotal connection 30 and
the supporting wheels 16.
Finally, reference is made to FIG. 5 for a more detailed understanding of
the coil packers 42 of the present invention. Specifically, the coil
packer 42 is comprised of a body having a major, central region 98 with
convolutions extending in a direction inclined relative to reference
planes perpendicular to the longitudinal axis of packer 42 (which is
coincident with the longitudinal axis of shaft 46). The body also includes
two opposed end regions 100 integrally connected to the central region 98
and extending in respective, parallel reference planes that are
perpendicular to the longitudinal axis of shaft 46. In this manner, each
of the coil packers 42 terminates at a location closely adjacent one of
the convolutions of the major, central region 98, to thereby effectively
tuck the free ends of the coil packers 42 inwardly and reduce the overall
length of the same.
As a consequence, each of the coil packers 42 can be positioned in closely
spaced, end-to-end disposition relative to the remaining coil packers 42
without leaving a substantial area of uncompacted soil as the implement 10
is advanced over the ground. Furthermore, the two endmost coil packers 42,
located at the outboard end of each wing frame member 22, are
advantageously somewhat shorter than the remaining coil packers 42 so that
the trailing harrow sections 66 are of a width sufficient to cover the
tracks left by field wheels 102 rotatably mounted on the outboard ends of
wing frame members 22. Moreover, by practice of the present invention, the
field wheels 102 are not damaged when the implement is folded to its
transport orientation, in comparison to certain of the conventional
implements where harrow sections and packer coils are in contact with the
field wheels during transport of the implement.
If desired, the implement 10 may be used for smoothing the ground without
compaction thereof by removal of the hair clips 58 and pins 54 in order to
detach the packer units 40 from frame members 22, 24. As an alternative,
one may wish to compact the soil without use of the harrow sections 66
which can easily be accomplished by disconnecting chains 68, 70.
Although the foregoing represents a detailed description of a currently
preferred embodiment of our invention, it is to understood in this regard
that various modifications or additional may be effected to the structure
shown in the drawings without departing from the gist and essence of our
contribution to the art. Accordingly, the invention should be deemed
limited only by a fair scope of the claims which follow along with their
mechanical equivalents thereof.
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