Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02275152 1999-06-15
LAND LEVELLER
FIELD OF THE INVENTION
This invention relates to a land levelling implement for levelling earth as
it is towed by a towing vehicle.
BACKGROUND
The use of V shaped ditches for drainage and irrigation is a common
agricultural practice. Before seeding a new crop, these ditches are usually
filled in,
using a land leveller which is commonly a blade mounted on a frame towed
behind a
tractor. The known levellers require multiple passes to fill a single ditch
and are
generally not adjustable to accommodate variations in the ditch profile and
terrain.
The present invention provides certain improvements in land levellers.
SUMMARY
According to one aspect of the present invention there is provided a land
leveller arranged to be towed by a vehicle for levelling earth, the land
leveller
comprising:
a frame;
a plurality of wheels supporting the frame for movement in a direction of
travel;
a hitch mounted on a forward end of the frame for connecting to the
vehicle;
a pair of blades mounted laterally spaced apart on the frame, each
blade having a contact edge extending transversely to the direction of travel
for
engaging the earth; and
pivotal mounting means mounting the blades on the frame for pivotal
movement about respective upright axes such that an angle between the contact
edge of each blade and the direction of travel is adjustable.
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Adjustment of the relative orientation of the pair of blades allows various
different tasks to be performed. When the blades are oriented to extend inward
and
rearward from respective outer ends toward respective inner ends, the leveller
can be
towed along a ditch such that each blade follows an opposite ridge of a ditch
for filling
the ditch in a single pass.
The frame preferably comprises a hitch member mounting the hitch
thereon, a pair of floating elements mounted on the hitch member for
independent
upward and downward deflections relative to the hitch members and a ground
support
for supporting the floating elements above the ground, the blades being
mounted on
the respective floating elements for movement therewith. This allows the
blades to
follow the ground contours as the blades engage the ground and the floating
elements
are deflected in response to the changes in elevation of the ground.
The plurality of wheels are preferably mounted on a rearward end of the
floating elements for deflecting the floating elements in response to
irregularities in the
ground.
The floating elements may be pivotally mounted on the hitch member for
pivotal movement about respective longitudinal axes being parallel to the
direction of
travel.
Preferably there is provided securing means for securing the blades at
various positions, each corresponding to a different relative angle between
the blade
and the direction of travel. The securing means may comprise a pair of locking
members mounted on the frame and arranged to engage the respective blades in a
locked position.
There may be provided hitch mounting means for mounting the hitch on
the frame at numerous vertical spacings between the hitch and the frame.
There may be provided wheel mounting means for mounting the wheels
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on the frame at numerous vertical spacings between the wheels and the frame
for
adjusting a height of the blades relative to the ground. The wheel mounting
means
may comprise a pair of wheel support frames mounting the wheels thereon, the
wheel
support frame being pivotally mounted on the frame for upward and downward
deflections relative to the frame. A hydraulic actuator is preferably provided
for
controlling the height of the wheels relative to the frame.
There may be provided lateral blade adjustment means for mounting the
blades on the frame at various laterally spaced positions on the frame.
There may additionally be provided numerous blades of different sizes,
each blade being arranged to selectively mount on the frame for different
applications.
According to a further aspect of the present invention there is provided a
land leveller arranged to be towed by a vehicle for levelling earth, the land
leveller
comprising:
a frame having a hitch member and a pair of floating elements mounted
on the hitch member for independent upward and downward deflections of the
floating
elements relative to the hitch member;
a plurality of wheels supporting the frame for movement in a direction of
travel;
a hitch mounted on a forward end of the hitch member for connecting to
the vehicle; and
a pair of blades mounted on the respective floating elements for
movement therewith, the blades being oriented to extend inward and rearward
from
respective outer ends toward respective inner ends, the inner ends being
spaced
apart.
This allows the blades to follow the ground contours as the blades
engage the ground and the floating elements are deflected in response to the
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changes in elevation of the ground. The blades are able to follow opposing
slopes of
a V shaped ditch for digging a ditch or follow opposing ridges of a V shaped
ditch for
filling the ditch.
The plurality of wheels are preferably mounted on a rearward end of the
floating elements for deflecting the floating elements in response to
irregularities in the
ground.
Preferably the floating elements are pivotally mounted on the hitch
member for pivotal movement about respective longitudinal axes being parallel
to the
direction of travel.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, which illustrate an exemplary
embodiment of the present invention:
Figure 1 is an isometric view of the land leveller connected to the hitch
of a towing vehicle.
Figure 2 is a top plan view of the land leveller.
Figure 3 is a side elevational view of the land leveller.
Figure 4 is a front elevational view of the land leveller.
Figure 5 is a top plan view of various blade orientations of the land
leveller in relation to the direction of travel.
DETAILED DESCRIPTION
Referring to the accompanying drawings, there is illustrated a land
leveller generally indicated by reference numeral 10. The land leveller 10 is
arranged
to level earth when connected to a hitch 12 of a towing vehicle which is not
shown.
The leveller 10 includes a frame 14 having a hitch member 16 and a pair
of floating elements 18 mounted thereon. The hitch member 16 is an elongate
beam
supported for movement in a forward direction indicated by arrow 20 or
rearward
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direction opposite to the forward direction. An adjustable hitch 22 mounts on
a
forward end 24 of the hitch member for connecting to the hitch 12 of the
towing
vehicle. The adjustable hitch 22 includes an engaging member 26 for engaging
the
towing vehicle and a plurality of mounting locations 28 for mounting the
engaging
member thereon. Each mounting location 28 corresponds to a different vertical
spacing between the engaging member and the hitch member for accommodating
different types of towing vehicles and different desired frame heights from
the ground.
The floating elements 18 are pivotally mounted on respective sides of
the hitch member 16 to extend laterally outward therefrom. A pair of pivots 30
are
mounted spaced apart on each side of the hitch member for mounting a
corresponding one of the floating elements thereon such that the floating
elements
are pivotal about respective longitudinal axes extending through the
respective pairs
of pivots 30 and parallel to the forward direction 20.
The floating elements 18 each comprise an inner member 32 adjacent
to and parallel to the hitch member and an outer member 34 spaced laterally
outward
from and parallel to the hitch member. A plurality of cross members 36 extend
between the inner and outer members of each floating element. Additional
bracing
members 38 connect between the cross members for additional support.
A forward cross member 39 on each floating element 18 is at an incline
to extend rearv~rard and outward from an inner end mounted on the
corresponding
inner member 32 to an outer end mounted on the corresponding outer member 34.
A
forward one of each pair of pivots 30 mounting the floating elements 18
thereon is
adjacent the forward end of the hitch member. The forward location of the
forward
pivots 30 and the incline of the forward cross members 39 reduces the
magnitude of
the moments acting on the pivots 30.
An adjustable mount 40 is mounted on each floating element 18 on a
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corresponding pair of the cross members 36. Each adjustable mount 40 mounts a
scraper blade 42 thereon. The scraper blades 42 are elongate plates having a
concave forward face 43 and a contact edge 44 along a bottom end for engaging
the
earth.
The adjustable mounts 40 are mounted on the cross members 36 by a
plurality of U-shaped bolts extending around the members and being secured at
respective ends by fasteners. Loosening the fasteners permits the adjustable
mounts
40 to be slid laterally inward and outward along the cross members 36 for
positioning
the blades on their respective floating elements at various lateral spacings
from the
hitch member. Tightening the fasteners will secure the corresponding
adjustable
mount 40 at the desired location.
The adjustable mounts 40 each include a shaft 46 having a generally
upright axis. The blades 42 are mounted on the respective shafts 46 for
pivotal
movement about the respective upright axes. The pivotal movement of the blades
about the respective upright axes allow the blades to be positioned at
numerous
angles facing forward or rearward. A locking plate 48 is mounted about each
shaft 46
and includes a plurality of apertures therein for receiving a locking member
50
therethrough. The locking member 50 engages one of the apertures and the
corresponding adjustable mount 40 for restricting pivotal movement of the
blade.
Each aperture in the locking plate 48 corresponds to a different relative
angle
between the hitch member and the contact edge 44 of the corresponding blade.
Numerous blades 42 of different sizes are provided, each being
arranged to selectively mount on the shafts 46 for accomplishing different
tasks with
the land leveller.
A wheel support frame 52 mounts on a rearward end 54 of each floating
element 18. A pair of pivots 56 are mounted on a corresponding cross member 36
at
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the rearward end 54 of each floating element for pivotally mounting the
corresponding
wheel support frame thereon. Each wheel support frame includes a connecting
member 58 mounted across each pair of pivots 56 and a pair of arms 60
extending
generally downward and rearward from the connecting member. The arms 60 are
parallel and spaced apart on their respective connecting members 58 being
supported
by additional bracing members 61. A wheel 62 is mounted on a free end of each
arm
60 for supporting the frame for movement across the ground in the forward or
rearward direction.
A crank 64 is mounted on each connecting member 58. A hydraulic
piston cylinder 66 pivotally mounts at a piston end on each crank 64 and
mounts at a
cylinder end on one of the bracing members 38 of a corresponding one of the
floating
elements. Contraction and extension of the hydraulic piston cylinders 66 will
pivot the
wheel support frames about their respective pivots 56 for adjusting a vertical
spacing
of the wheels in relation to the respective floating elements of the frame.
In operation, the blade angles and location of the blades are first
adjusted to any desired position. Adjustment of the hitch and wheel supports
will then
adjust the height of the blades relative to the ground for selecting the depth
of cut of
the blades into the ground. As the leveller 10, is towed across the ground,
the wheels
on each floating element roll over irregularities in the ground height for
deflecting the
corresponding floating element and blade mounted thereon upward and downward
with the elevation of the terrain. Each floating element is also arranged to
follow the
inclination of the terrain as the floating elements pivot about respective
longitudinal
axes extending through the pivots 30.
Adjustment of the blade angle and location of the blades are selected
depending on the desired task. As illustrated in Figure 2, the blades can be
oriented
in a ditch filling position. In the ditch filling position, the blades form a
V-shape with
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the apex pointed rearward. The inner ends of the respective blades are spaced
from
each other. The leveller is then pulled longitudinally along the ditch with
each blade
being aligned with one of the banks of the ditch for filling the ditch with
earth in a
single pass.
The orientation of the blades when filling both sides of a ditch while
pulling the land leveller behind a towing vehicle, is shown in Figure 5a. The
angle of
the blades are shown in a V-shape with the apex extending rearward in relation
to the
forward direction 20.
As shown in Figure 5b, the blades can also be oriented in a V-shape
with the apex extending forward and the inner ends of the respective blades
being
located adjacent each other. In this orientation, the blades will plough a
ditch when
pulled across the ground in the forward direction 20.
As shown in Figure 5c, the blades can be positioned parallel to each
other and co-linear with the inner ends located adjacent to each other, for
use as a
single bladed scraper.
In Figure 5d, the blades are shown parallel and at an angle to the
forward direction with the inner ends of the blades overlapping each other.
This
arrangement is useful for moving earth in a single direction. In the previous
arrangements the forward faces 43 of the blades are oriented to face forward
and the
leveller is arranged to be pulled in the forward direction.
Alternatively, the blades can be positioned as shown in Figure 5e with
the forward face 43 of each blade facing rearward. In this manner, the
leveller can be
pushed by the towing vehicle in a rearward direction 68 opposite to the
forward
direction 20. This is particularly useful in areas where the ground is too wet
for a
towing vehicle to pass over or if it is dangerous for the vehicle to be
located ahead of
the leveller.
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In an alternative arrangement, the blades can be mounted on the frame
with hydraulic actuators controlling the depth of cut of the blades as well as
the
inclination of the blades in relation to the forward direction.
While one embodiment of the present invention has been described in
the foregoing, it is to be understood that other embodiments are possible
within the
scope of the invention. The invention is to be considered limited solely by
the scope
of the appended claims.
