Note: Descriptions are shown in the official language in which they were submitted.
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SOIL TILLAGE IMPLEMENTS AND SHEAR WHEELS FOR USE WITH TRACTORS
FIELD OF THE INVENTION
The present invention relates to the field of agricultural equipment, and more
particularly to
soil tillage implements for decompacting soil terrain.
s BACEGROUND OF THE INVENTION
Most of the world's soils are topographically classified as clay type soils.
Soils are primarily
composed of mixtures of clay and sand. Soils are compacted, naturally
compactive, or
compactable at a ratio which is proportionate to the amount of clay in the
soil. The arability of
soils is significantly impacted by the composition ratio of clay to sand. The
sand component
in will absorb water and nutrients, but it is unable to retain these
elements. Clay can retain
nutrients, but is poor at absorbing water. The stronger molecular attraction
and cohesion
forces of clay cause individual clay particles to mutually cohere. This
condition, known as
colloidal clay hysteresis, prevents a clay soil mass from molecularly
absorbing the given
surface rainwater and humus. Clay tends to become tightly compacted as it
loses water and
15 dies out. Although rich in nutrients, the clay may become so compacted
and hard, that plant
roots cannot penetrate the clay to access the nutrients. Good arable soil has
a mix of clay to
retain nutrients and sand to absorb water and loosen and aerate the clay and
permit
drainage. The world's best agricultural soils are deep foams. Deep loam are a
mixture of
sand and clay in approximately a 1:1 ratio. Soils having such a mixture to a
depth of about 3
20 feet are ideal for growing_ Typically the soils rest upon a high
percentage clay subsoil.
Warns do not crack open as readily as clay topsoil when they dry. Thus
moisture from below
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the surface of the loam soils is not lost easily lost, since cracks are not
present to permit
moisture to escape. Regions where the soil mixture is lacking either adequate
clay or lacking
adequate sand will have land which is less suitable for growing crops. It is
believed that soil
management techniques which intermix clay with sand can improve the quality of
soil, and
increase the arability of the land in regions previously having only
marginally arable soil. The
intermixing of clay and sand first requires the decompacting of clays. Even in
areas where
there is an adequate (though not ideal) mix of soil and clay, the clay content
may be
compacted, and therefore unable to absorb surface water needed for optimal
plant growth.
Decompacting the clay can substantially improve soil quality and arability.
It is an object of the present invention to provide an implement for tilling
soil which is effective
to decompact high clay content soils.
It is a further object of the present invention to provide a method of
decompactIng soil.
It is yet another object of the present invention to a shear wheel for a
tractor which provides
improved traction and which does not exacerbate the compacting of soils.
SUMMARY OF THE INVENTION
There is disclosed an implement for tilling soil, having a frame and a means
for coupling to a
traction vehicle, and being capable of being pulled by the traction vehicle in
a direction of
travel. The frame bears a blade housing plate and a plurality of shearing
blades mounted to
the blade housing plate in vertically spaced apart relation and oriented
substantially parallel
to the surface of the soil. The plurality of shearing blades are mounted to
the blade housing
plate so as to be deflectable to an out of the way position upon contacting an
obstacle in the
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soil.
A tractor shear wheel is provided for moving on soil terrain. The tractor
shear wheel
comprises a rotatable hub having a tractor axle mounting and at least one rim
spaced radially
outward from the hub. A plurality of paddles is angularly offset from one
another and extends
radially outward from the hub. The plurality of paddles have radially
outermost ends which
are fixed to the at least one rim. The tractor shear wheel rides on the soil
terrain on the radial
outermost ends of the paddles.
A method is provided for decompacting a soil terrain. The first step in the
method is making
a first tilling pass in a first direction along the terrain with an implement
for tilling soil thereby
shearing the soil terrain into layers, lifting the sheared soil and allowing
it to settle. The
implement for tilling soil comprises a frame having a means for coupling to a
traction vehicle
and being capable of being pulled by the traction vehicle in a direction of
travel. The frame
bears a blade housing plate and a plurality of shearing blades mounted to said
blade housing
plate in vertically spaced apart relation and oriented substantially parallel
to the surface of the
soil. The second step in the method is making a second tilling pass, in a
direction diagonal to
said first pass, along the terrain with said implement for tilling soil,
further shearing the soil
terrain into layers, lifting the sheared soil and allowing it to settle.
Subsequent tilling passes
may be made in the direction of the first pass or the second pass at a depth
deeper within the
soil terrain.
An apparatus is provided for decompacting of soil terrain comprising a
traction vehicle fitted
with a plurality of tractor wheels. Each of the tractor wheels has a rotatable
hub having a
tractor axle mounting; at least one rim spaced radially outward from said hub.
A plurality of
paddles, angularly offset from one another, extend radially outward from the
hub. The
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paddles have radially outermost ends and are fixed to the at least one rim.
The tractor wheel
rides on the soil terrain on the radial outermost ends of the paddles. The
traction vehicle
coupled to an implement for tilling soil having a frame bearing a blade
housing plate a
plurality of shearing blades mounted to the blade housing plate in vertically
spaced apart
relation and oriented substantially parallel to the surface of the soil.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a side view of a traction vehicle with soil tillage implements and
shear wheels
according to a preferred embodiment of the present invention.
Fig. 2 is a partial top view of the soil tillage implement shown in Fig. 1.
Fig. 3 is a top plan view of a plurality of shearing blades according to the
present invention.
Fig. 4 is an enlarged perspective view of a blade housing according to a first
embodiment of
the present invention.
Fig. 5 is an enlarged perspective view of a blade housing according to a
preferred
embodiment of the present invention.
is Fig. 6 is an enlarged partial perspective view of a blade housing,
having a trenching wedge
and injector according to an embodiment of the present invention.
Fig. 7 is a side view of a tilling implement shown tilling a soil terrain,
said soil terrain being
shown partially in section.
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Fig. 8 is a top view of a tilling implement shown tilling a soil terrain.
Fig. 9 is front view of a traction vehicle having tractor wheels according to
an embodiment of
the present invention.
Fig 10 is a side view of a first embodiment of the tractor wheel according to
the present
6 invention.
Fig 11 is a side view of a second embodiment of the tractor wheel according to
the present
invention.
Fig 12 is a perspective view of the second embodiment of the tractor wheel of
Fig. 11,
DETAILED DESCRIPTION OF TI IL PREFERRED EMBODIMENT
Referring now to Fig 1 of the drawings, a traction vehicle 10 is shown making
a tilling pass
through a soil terrain in a direction of travel shown by the arrow "C". The
surface of the soil is
indicated by reference numeral 12. The traction vehicle 10 is fitted with
tractor wheels 14.
An implement for tilling soil is shown by general reference numeral 16. The
implement for
tilling soil 16 has a frame 18. The frame 18 has a means for coupling to the
traction vehicle
represented by reference numeral 20. In Fig 1, the means for coupling 20 is
shown as a
standard three-point hitch. The means for coupling may also be equipped with
hydraulic
lifting cylinders 22, as best seen in Fig 2. It should be noted in Fig. 2 that
the traction vehicle
10 and the hitch are not shown. The use of hydraulic cylinders 22 will permit
the implement
for tilling soil to be deployed at a desired height relative to the surface 12
of the soil. In this
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manner, the depth of tilling can be controlled, and the tilling of the soil to
greater depths can
be facilitated by carrying out multiple tilling passes through the soil, each
with the implement
for tilling soil 16 deployed at greater depths within the soil.
The entire implement for tilling 16 can be constructed from metal plates. The
frame can be
constructed from reinforced steel, such as I-beam, or box frame assemblies.
The particular
selection and assembly of framing members is a routine matter which would be
readily
understood be a person skilled in designing and constructing farming
implements.
The frame 18 bears a blade housing plate 24. As can be seen in Fig 2, it is
preferred to have
several blade housing plates 24 attached to the frame 18. The structural
details of the
implement for tilling will be discussed and illustrated in connection with a
single blade
housing plate, but it should be recalled that tilling implement 16 preferably
several blade
housing plates 24, mounted in a row. Each blade housing plate 24 has a
sharpened leading
edge 28. The phrase "leading edge" refers to the edge of the housing plate
which would first
contact the soil as the implement for tilling is pulled in a direction of
travel (as identified by
arrow "C" in Fig. 1). A sharpened tooth 30 projects forward of the leading
edge 28 at a lower
extent thereof. As can be seen in Figs. 1, 4 and 5, the blade housing plate 24
may be
advantageously provided with a plurality of teeth 30. The teeth 30 are angled
and they will
bite downward into the soil as the implement is pulled through the soil. As
the teeth bite
downward a down draught is created which helps to maintain the stability of
the implement
16 in the soil by keeping the shearing blades in contact with the soil,
preventing wobbling of
the implement or lifting of soil masses before the soil is sheared.
By way of example, the blade housing plate 24 may be constructed of alloy
steel plate having
thickness of 0.5 to 2.0 inches. Typically the housing may be approximately 4
feet high and
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approximately 4 feet long. The dimensions of the blade housing and the quality
and strength
of the steel used in its construction could be readily determined by a person
skilled at
designing and constructing farm implements, having regard to the overall
desired tilling
capacity for the implement 16, including coverage width for each tilling pass
of the
implement, the pulling strength of the traction vehicle for use with which the
implement is
designed, the required depth of tilling, and the hardness of the soil to be
tilled.
As best seen in Figs 3 and 4, a plurality of shearing blades 26 are mounted to
each blade
housing plate 24 in vertically spaced apart relation. The shearing blades we
oriented
substantially parallel to the surface of the soil 12. The shearing blades 26
have sharpened
leading edges 32 to enable the shearing blades 26 to cut or shear through the
soil in layers.
The sharpened leading edges 32 can be created by insetting a high tensile
sharpened steel
knife into each leading edge, or (preferably) by machining a sharpened edge
into the steel
from which the shear blade is constructed. Machining the shear blades to
create the
sharpened leading edges is preferably accomplished by machining an inclined
face on the
leading edge of the shearing blade. The angle of inclination may be varied,
but experience
has shown that an angle in the range of 10-20 degrees is preferable. As a
result of the
vertically spaced apart arrangement of the shearing blades 26, the soil is
sheared into
several layers. The inclined face of the sharpened leading edge helps to raise
the sheared
soil from the blades. The sheared soil will then settle after the implement
has passed. The
particular number of shearing blades mounted to each housing plate is not a
matter of
importance to the present invention. The number of shearing blades may be
selected based
upon the desired thickness of the sheared layers of soil and the depth of the
tilling to be
achieved with each pass of the implement. By way of example, the implement may
be
constructed having five shearing blades in vertically spaced apart relation,
with approximately
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3 inches clearance between each shearing blade. This embodiment would
efficiently slice
soil into layers of about 3 inches in height.
As the implement is pulled at increasing speed along the direction of travel,
the sheared
layers of soil maw attain a sufficient momentum to weight ration to allow the
soil to be lifted in
a rooster tail arc. The arcing and then settling of the 3 inch layers of soil
would allow the soil
to become turbulent and crumble, with the result that the settled soil is less
compacted.
Little, if any, of the soil is displaced laterally along the terrain by the
use of the piesent
invention.
It is preferable for the shearing blades 26 to be substantially sector shaped,
having two
leading edges 32, and a curved trailing edge 34. Each blade is provided with a
mounting
tongue 36 positioned between said two leading edges 32. The mounting tongue 36
defines
an opening 38 for receiving a fastener 39 therethrough. The shearing blade 26
is pivotable
about the fastener 39 (shown in dotted outline in Figs. 4 and 5) when the
shearing blade is
mounted to the blade housing plate 24.
As can be seen in Figures 3-5, the leading edges 32 of the shearing blades 26
extend
outwardly and rearwardly from the mounting tongues 36 of the shearing blades
26. It is
preferable, though not necessary for the extension to be at approximately a 45
degree angle.
The size of shearing blades may be varied as desired, having regard to the
overall desired
size and tilling capacity of the implement 16. By way of example, the shearing
blades may
be constructed to extend approximately 6 inches laterally outward from either
side of the
blade housing plate, for a total blade span of approximately 12 inches. The
depth of the
sector shape may also be approximately 6 inches. Typical thicknesses for the
blades range
between 0.5 and 1.0 inches. The use of larger or smaller shearing blades
should be
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understood to be within the scope of the present invention. The shearing
blades are
constructed from alloy steel. The selection of steel strength and the
thickness of the blades
are within the competency of a person skilled in the art of designing and
constructing farm
implements.
The shearing blades 26 are deflectably mounted to the blade housing plate 24.
Various
embodiments of the manner of mounting of the blades, and the particular
direction of
defection of the blades can be understood within the present invention.
In a preferred embodiments of the present invention, the shearing blades 26
may be bolt
mounted to the blade housing plate 24. As illustrated in Figs. 4 and 5, the
blade housing
plate 24 defines a plurality of sockets 40 to lockingly receive a plurality of
fasteners 39. The
locking function can be accomplished by screw threading of the sockets, and
the use of
complementary threaded bolts as fasteners. When mounted, the shearing blades
26 will be
pivotable about the fasteners, allowing the shear blades 26 to deflect
laterally upon
encountering soil obstacles 25. Typically when the implement 16 is being
pulled in a
direction of travel, about half of the shear blade 26 lies on either side of
the blade housing
plate 24. Upon encountering a soil obstacle 25, the shearing blade will pivot
in a horizontal
plane about the axis of the fastener (bolt) away from the obstade 25, allowing
the implement
16 to continue working the soil without tripping the trip bar. in this manner,
the present
invention may afford increased efficiencies and a reduced incidence of damage
to the shear
blades 26. This deflection of a shearing blade 26 can be seen in Fig. 5.
In the alternate embodiment shown in Fig. 5, the blade housing plate 24 forms
a dosed
structure protecting the shearing blades 26. The blade housing plate 24
defines a plurality of
horizontal slots 42 therethrough, each sized and positioned for throughpassage
one of said
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shearing blades 26. The shearing blades 26 are mounted to the blade housing
plate 24 so
as to be deflectable to an out of the way position upon contacting an obstacle
25 in the soil.
Fig. 5 shows a blade 26 in a deflected position of one of the shearing blades
26.
The blade housing plate 24 defines a plurality of sockets 40 to lockingly
receive the fasteners
39 (typically bolts) holding each of the shearing blades 26 in place. The
blade housing 24
has means for buttressing the curved trailing edges 34 of the shearing blades.
The
buttressing means could take several forms. In one example shown in Fig. 5,
the buttressing
means comprises a contact pin 46 (shown in dotted outline) seated within each
horizontal
slot 42 through the blade housing plate 24, to supportingly contact the curved
trailing edge 34
of each of said shearing blades 26. Preferably the contact pins are threaded
and can be
threadingly engaged into a plurality of threaded recesses 44 within the blade
housing plate
24. The contact between the trailing edge 34 of a shearing blade and its
respective contact
pin 46 will cause a groove to wear in the contact pin 46 over time. By having
the contact pin
46 take the wear, the blade housing 24 is protected from wear. As the contact
pin becomes
worn, it can be adjusted to protrude far enough into the slot 42 of the
housing to again make
buttressing contact with the curved trailing edge 34 of the shearing blade 26.
The buttressing
pressure of the contact pin against the shearing blade stabilizes it,
preventing unnecessary
wobble and/or pivotal movement of the shearing blade 34 about the fastener 39
(unless the
shearing blade 26 contacts an obstacle 25). Additionally, as the implement 16
is pulled in a
direction of travel and the shearing blades shearingly enage the soil, there
is significant
rearward pressure placed on the shearing blade, and specifically focused on
the mounting
tongue 36 at the opening for receiving 38 for the fastener 39. Considerable
wearing of the
fastener 39 and/or the opening 38 can occur. If the shearing blade 26 is
buttressed as
discussed here, the contact pin will take some of the pressure on the shearing
blade 26
CA 02782822 2013-10-08
lessening the potential for wear on the fastener 39 and the opening 38 in the
mounting
tongue 38 for receiving the fastener.
As best seen in figs. 6 through 8, the implement 16 may further comprise a
trenching wedge
48 which is contiguous with the trailing edge 50 of the housing plate 24. The
trenching
wedge 48 comprises a first trailing wing plate 52 and a second trailing wing
plate 54, both of
which extend outwardly from the trailing edge 50 of the housing plate 24
forming a V-shaped
opening therebetween. The first 52 and second 54 wing plates span top to
bottom with the
trailing edge 50. The centre portion 56 of the wedge, where the first 52 and
second 54 wing
plates, preferably has a width similar to that of the blade housing plate 24.
The wings 52, 54
may be fixedly attached to the blade housing 24, or they may be integrally
formed as a
continuation of the blade housing 24. In use, as the implement 16 is pulled in
a direction of
travel "C", soil encounters the trenching wedge 48 after it has been sheared
by the shearing
blades, lifted by its motion across the blades, lifted, and loosed. When the
soil encounters
the one of the wing plates 52, 54 it is directed outwardly following the
outward angles of the
wing plates. When a plurality of blade housings having a corresponding
plurality of trenching
wedges are fixed to the frame 18 in a row, interference between the soils
moved by
neighboring wing plates on neighboring blade housings will cause soil to
accumulate and be
lifted.
An injector 60 is positioned above the trenching wedge 48 to receive the
lifted soil, and to
inject it downwardly behind the trenching wedge 48 into the lower levels of
the soil. The use
of the trenching wedge and injector are particularly advantageous in tilling
environments
having very sandy top soils and hard compacted clay sub-soils. In such soils
the finely
divided claim may have separated from the topsoil and become lost, leaving
sandy top soils
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which have a tendency to drift. The use of this embodiment of the implement
can result in a
re-mixing of clay and sand components by injecting sand down into the clay
subsoil. The
presence of trenches created by the trenching wedge 48 further serve to hold
rain water and
prevent water loss due to surface runoff. The resultant tilled soil has been
mixed by tilling,
trenching, and injection, and water is better able to soak into soil treated
in this manner.
The frame 18 can also be fitted with trip release bars 23 with articulating
hinges that will allow
the blade housing plates 24 to lift up out of Me soil In response to contaci
with a
predetermined resistance or a soil obstacle, such as rock, within the soil.
The trip bar 23 can
be reset and the tilling implement 16 lowered back into contact with the soil
after the
obstruction has been cleared.
In a further embodiment of the present invention, a tractor shear wheel 62 is
provided for
moving on soil terrain. In Figs. 9-12, the shear wheel is identified by the
general reerence
numeral 62. The shear wheel comprises a rotatable hub 84 having a tractor axle
mounting
66. At least one rim 68 is spaced radially outward from said hub 64.
Preferably there will be
more than one rim 68. A plurality of paddles 70 which are angularly offset
from one another
extend radially outward from the hub 64. The paddles 70 having radially
outermost ends 72.
The paddles 70 are fixed to the rim 68. The tractor shear wheel 62 rides on
the soil terrain
on the radial outermost ends 72 of the paddles 70. The outermost ends 72 may
extend
beyond the rims 68 as shown in Fig. 10. Alternatively, the outermost ends 72
may be kept
flush with the rims 68. The outermost ends of the paddles may be pointed, as
shown in Fig
10, or they may be blunt, as shown in Fig. 11. In use, the tractor shear
wheels provide
improved fraction when compared to rubber tires. The paddles initially engage
the soil
surface on a diagonal angle so as to provide maximum shearing or traction
force when the
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paddle at the bottom of the rotation is at its maximum penetration depth
within the soil. The
leading edge of the next blade engages the soil surface at roughly a 45 degree
angle which
maximizes the size of its bite. Travel through the soil is made more efficient
than if one relies
on the treads of rubber tires. There is minimal contact between the shear
wheel and the
ground in the present invention. This results in a reduced tendency of the
wheels to roll over,
break or flatten crops which have emerged. There is shearing of the soil as
the shear wheels
contact the soil during rotation. This action of the paddles provides better
traction to the
traction vehicle and permits more efficient pulling of the tilling implement.
The action also
provides some dissection of the soil, potentially breaking up heavily
compacted sections,
io The shear wheels according to the present invention do not waste work
energy generated by
the tractor in slipping or by pushing a wave of soil ahead of the wheels (as
is the case with
rubber tires).
In accordance with the present invention, there is disclosed a method for
decompacting a soli
terrain comprising the following steps. Making a first tilling pass in a first
direction along the
is terrain with an implement for tilling soil 16. As discussed above in
greater detail, the
implement 16 comprises a frame, having a means for coupling to a traction
vehicle and being
capable of being pulled by the traction vehicle in a direction of travel. The
frame bears a
blade housing plate. A plurality of shearing blades are mounted to the blade
housing plate in
vertically spaced apart relation and oriented substantially parallel to the
surface of the soil.
20 During the first tilling Pass, as the shearing blades contact the soil
terrain, it is sheared inlu
layers, lifted, and then allowed to settle. The next step in the method is
making a second
tilling pass, in a direction diagonal to said first pass, along the terrain
with said implement for
tilling soil, further shearing the soil terrain into layers, lifting the
sheared soil and allowing it to
settle. Subsequent tilling passes may be made with the implement 16 for
tilling soil either
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over the soil terrain in the same direction as the first passes or the second
passes at a
deeper depth within the soil terrain. By practicing this method, a user can
horizontally shear
hard clay soils into many thin layers and loosen the soil by lifting the
layers a small distance
and allowing them to settle into place. By repeating tilling passes by the
implement at
progressively greater depths, the subsoil can be decompacted at much greater
depths than
could be accomplished if soil was ploughed or turned over using conventional
equipment If a
user wishes to loosen the soil while maintaining the existing soil strata, the
tiling implement
can be used without the trenching wedge and injector. The tilling implement
can be used in
situations where it is desirable to mix the layers of soil, such as in soil
reclamation efforts in
desert or near desert regions. In such instance, surface sand could be
injected downward
into the deeper clay layers to create soil having more favorable clay to sand
ratio.
It will be obvious to those skilled in the art that modifications of the
present invention may be
adopted without departing from the spirit of the present invention. Changes
may be made in
the combination dud arrangement of the various parts and elements, described
heroin
without departing from the spirit and scope of this invention. It will be
apparent that the scope
of the present invention is limited only by the claims set out hereinbelow.
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