Note: Descriptions are shown in the official language in which they were submitted.
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" GROUND WORK ING SWEEP "
BACKGROUND OF THE INVENTION
This invention relates to ground working sweeps
of the type which can be attached to a cultivator or deep
tillage apparatus for working the ground. Conventional
sweeps are well known and widely used and comprise an
arrow-shaped head with a flange centrally of the sweep
inclined upwardly and rearwardly for attachment to the
conventional tine. The edges of the sweep lie in a
generally horizontal plane when the sweep is positioned
for use and are inclined rearwardly and sidewardly from a
central point so as to cut through the ground beneath the
surface. The edges of the sweep are generally sharpened
so as to provide cutting edges which reduce the power
required to draw the sweep through the ground.
Careful observations and study ky the present
inventor have revealed that firstly the sweeps tend to
wear at the rearmost corner of the cutting edge as the
earth brushes past the rearmost corner, thus gradually
reducing the working width of the sweep. Furthermore and
more importantly, the sweep tends to be ineffective in
that it merely tends to push aside weeds under the soil
surface rather than to cut the weeds as intended.
SUMMARY OF THE INVENTION
_
It is one object of the present invention
therefore to provide an improved sweep which can be
manufactured simply and cheaply similar to the
construction of the present or conventional sweep and yet
provides a modified shape which improves performance.
Accordingly the invention provides a ground
working sweep comprising a metal body having a means for
attachment of the body to a support tine whereby the sweep
can be drawn through the earth, a cutting edge of the
sweep projected forwardly from the tine for engaging the
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earth as the sweep is moved through the earth, the cutting
edge having a forwardmost central point and two side edges
which extend from the point and each of which includes a
first substantially straight portion inclined sidewardly
and rearwardly away from the point relative to a
longitudinal axis central to the sweep and a second
substantially straight portion contiguous with the first
and substantially at right angles to the longitudinal axis.
In another aspect, the invention provides a
ground working sweep comprising a metal body having means
for attachment of the body to a support tine whereby the
sweep can be drawn through the earth, a generally V-shaped
cutting edge of the sweep projected forwardly from the
body for engaging the earth as the sweep is moved through
the earth, the cutting edge comprising a forwardmost
central point and two side edges which extend from the
point and are inclined sidewardly and rearwardly away from
the point relative to the longitudinal axis central to the
sweep, wherein outer edges of the sweep intersecting the
side edges lie substantially parallel to the axis.
s with the conventional sweeps, the cutting
edges preferably lie in a horizontal plane so that the
edge cuts through the soil beneath the surface.
Thus the cutting edges provide a pair of wings
which extend outwardly from the sides of the sweep to
ensure that weeds contacted by the sweep are cut by the
cutwardly extending wings rather than merely brushing past
the outside edges of the sweep. In addition the outwardly
extending surfaces reduce the tendency of wear of the
edges to reduce the working width of the sweep, thus
providing a sweep which will last for increased numbers of
working hours.
ith the foregoing in view, and other advantages
as will become apparent to those skilled in the art to
which this invention relates as this specification
proceeds, the invention is herein described by reference
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to the accompanying drawings forming a part hereof, which
includes a description of the best mode known to the
applicant and of the preferred typical embodiment of the
principles of the present invention, in which:
DESCRIPTION OF THE DRAWINGS
Figure l is a plan view of a ground working sweep
according to the invention.
Figure 2 is an isometric view showing the sweep
of Figure 1 attached to a support tine and trip mechanism
of a cultivatorD
Figure 3 is a cross sectional view along the
lines 3-3 of Figure l.
Figure 4 is a plan view of a conventional
cultivator sweep.
In the drawings like characters of reference
indicate corresponding parts in the different figures.
DETAILED DESCRIPTION
Turning firstly to Figure 4 there is shown a
conventional cultivator sweep of the type which i9 widely
used in the industry. The shape of the sweep has become
almost universally accepted and any differences between
competing models are hardly discernible. As shown the
shape is substantially in the form of an arrow with two
side edges 11 and 12 of the sweep 10 leading from a point
13. The edges 11 and 12 and the point 13 thus form the
ground working surfaces and are sharpened at 16 to assist
in working the soil and in cutting subsurface weed
structures.
Turning now to the present invention which is
illustrated in Figures 1 and 2, the sweep is illustrated
at 20 attached to a tine 21 which is supported on a trip
mechanism 22 of conventional form. The tine is
substantially rigid so as to hold the sweep in constant
position beneath the surface of the soil except when
tripped by contact with a stone or other solid object.
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The sweep itself is formed of a unitary integral
body and includes a flange 23 which is inclined upwardly
and rearwardly relative to the cutting edges of the sweep
for engagement with the downwardly depending shank 21.
From the flange 23, the central upper surface of
the sweep curves downwardly as at 2~ toward a point 25 at
the forwardmost position of the sweep. The point 25 also
comprises the lowermost position on the sweep with the
cutting edges indicated at 26 and 27 extending rearwardly
and sidewardly from the point and lying in substantially
the same horizontal plane so that the cutting edges on the
point cut through the soil in a continuous horizontal
plane.
The side edges of the flange indicated at 28
extend down toward the rear of the blade portion of the
sweep to a rear edge 29 of the blade, which rear edge lies
in a plane higher than the cutting edge to provide an
upper surface of the blade which extends generally
upwardly and rearwardly from the cutting edge 26 back
toward the rear edge 29.
The wings are therefore slightly curved upwardly
and rearwardly from the front edge 262 to the rear edge 29
to increase suction behind the sweep and to assist in
throwing cut weeds upwardly to the surfaceO
The rear edge 29 includes a first portion 291
parallel to the front edge 262, and a second portion 292
extending forwardly and inwardly therefrom to the base of
the flange 23. The portion 292 is substantially parallel
to the edge 261 and is spaced therefrom by a distance
substantially equal to the spacing between the edges 262
and 291. In this way, wear occurring on the edges 26 and
262 tends to eat into the body of the sweep to approach
the edges 291, 292 respectively at the same time so that
thP sweep is fully worn when little material is left at
the edges 291, 292.
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As shown in best detail in Figure 1, the edges
26, 27 include a first portion which is substantially
straight and extends rearwardly and outwardly from the
point 25 and indicated at 261, and a second portion 262
which lies at an angle to the first portion and projects
generally directly outwardly from or at right angles to a
central axis passing through the point 25. The change of
direction between the two portions 261, 262, is
substantially immediate so that any weeds running back
along the edge 261 contact the edge 262 and are cut by
that edge rather than tending to curve away past the
outermost portion of the edge 262. The edges 262 and 272
are shown in Figure 1 as lying at right angles to the axis
30 but it will be apparent that this direction can be
modified provided that there is a change of direction from
the portion 261 so as to extend more sharply outwardly so
that weeds contact the edges 262 and 272.
The edges 262, 272 thus efectively form wings
which are additional to the conventional accepted form of
the sweep shown in Figure 3. These additional wings
provide additional material adjacent the outermost edges
of the sweep so that wear does not initially cause a
reduction in the working width of the sweep but tends
merely to curve the outer point indicated at 263 of the
edge 262 and the rear point 26~ of the outer straight edge
265 of the wing portion. This straight edge 265 is
different from the conventional sweep and lies generally
parallel to the direction and motion oE the sweep whereas
the outermost portion of the conventional sweep comprises
merely a point indicated at 14, 15 where the edge turns
immediately back toward the axis.
In one example, the length of the edge 265 is of
the order of three inches and the rear end thereof is 3/4
inch higher than the front end thereof giving an
inclination of the order of 20D. The length of the edges
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262 and 272 is of the order of 3/4 inch and this dimension
can be used in sweeps of different overall size.
The method of attachment using a flange with two
holes can be modified in accordance with the requirements
to accommodate conventional variations in the shank 21.
The sweep can be effectively planar if required, whereby
the center line 24 lies in the same plane as the edges 26
and 27.
Since various modifications can be made in my
invention as hereinabove described, and many apparently
widely different embodiments of same made within the
spirit and scope of the claims without departing from such
spirit and scope, it is intended that all matter contained
in the accompanying specification shall be interpreted as
illustrative only and not in a limiting sense.
