Note: Descriptions are shown in the official language in which they were submitted.
11137~8
Harrows for working the soil, expecially ones for working in
fields, are generally in several sections arranged adjacent to each other
and linked together. Normally, the considerable width of the harrow - 5-15
metres in the working position - can be reduced to around 3 metres by folding
inlthe external sections towards and onto the central section, thus allowlng
transportation on the roads. The central section is then equipped with a
coupling element for towing, and transportation wheels.
Each harrow section is composed of a frame formed by bars to
which several parallel pivots are rotatably connected, being arranged in the
transverse direction of the harrow and having fixed on them the harrow prongs
or tines for working the soil. Each frame is held up by support elements
which are generally in the form of skids or wheels, and which can be adjusted
vertically by means of adjustment devices to regulate the working depth of the
harrow tines. When the frame has been height-adjusted all the harrow tines
arranged on the frame have the same working depth.
As already mentioned, the pivots for the harrow tines are rotatable.
; This means that the harrow tines can be adjusted so that the points of the
tines which work the soil take up the desired effective angle in the ground.
Each harrow section has separate adjustment devices both for the
working depth and for the effective angle. Adjustment is not very practical,
due to the fact that the adjustment devices are sited at different points on
the harrow and are frequently relatively far apart. The invention eliminates
this problem and aims to produce a harrow with very easy manipulation.
The invention will now be described in more detail with reference
to the attached drawings. Figure 1 is a plan view of a harrow. Figure 2
shows the harrow with certain parts sectioned along the line II-II in Figure 1.
Figure 3 shows the harrow viewed from the right-hand side of Figure 1.
In Figure 1, the numeral 1 designates the harrow as a whole. In
the construction from shown, the harrow is composed of a central section 3
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with lateral sections 4a and 4b arranged on either side of it. By means of
articulated connections 5a and 5b the central section is pivotably connected
to the lateral sections disposed on either side externally to the central
section. The lateral or external sections can thus be pivoted upwards and
inwards relative to the central section to reduce the width of the harrow,
preferably when being towed on the road. For this purpose the harrow is
equipped with a tow-bar 2 which is attached to the front cross-bar 6 of the
frame of the central section. The front cross-bars of the lateral sections
are designated 7a and 7b respectively. The sections also have bars connected
to the cross-bars 6, 7a and 7b, the bars of the central section being desig-
nated lla and llb, while those of the left and right external sections are
designated 12a and 12b respectively.
The rotatable pivots 15 for the harrow tines are arranged between
the bars lla, llb on the central section, and the harrow tines 14 are set on
these pivots in such a way that their points or tips dig into and work the
soil, as will be described in more detail below. In the same way, the pivots
13 for the harrow tines extend between the bars 12a and 12b of the lateral
sections and the fixed harrow tines 14 are arranged on these pivots as shown
in the right-hand part of Figure 1. The arrangement for making the harrow tine
pivots rotate is described and shown in more detail relative to Figure 3.
The frames of the sections are held up by support elements resting
on the ground which are vertically movable relative to the frames, so that the
latter and the rotatable pivots for the harrow tines may be ad~usted to differ-
end distances above the ground. In this way, the points of the harrow tines
may also be adjusted to penetrate to different depths in the ground, that is,
so that they obtain different working depths.
In the embodiment shown, the support elements of the central section
are formed by bogies 8a and 8b fitted with wheels and attached inside the frame
of the central section. As the latter is supported by the towing eye of the
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tow-bar and by the four wheels, it travels very smoothly, even over very
rough ground. The arrangement will be described in more detall relative
to Figure 2.
The support elements of the external sections are formed by skids
16 arranged vertically pivotable on the external bar of the relevant external
section, and connected pivotably to the respective bars 12a and 12b by means
of articulated parallel arms slanting downwards. 17 designates the front
articulated arms and 18 designates the rear articulated arms. The skids are
very long, so that the external sections also travel smoothly over rough ground.
The front articulated arms 17 are attached to the external ends by
transverse torsion bars 19 extending along the cross-bars 7a and 7b. At their
internal ends pointing towards the central section, the torsion bars are fitted
with arms 20a and 20b pointing upwards and located directly above the articulat-
ed connections 5a and 5b. The pivoting of the components 20b, l9b and 17b
makes it possible to adjust the support element 16b in the form of a skid, by
means of the rear skid arm 18b, to different heights relative to the frame of
the central section, so that the rotatable pivots for the harrow discs thereof
may be adjusted to different distances above the ground. The upper end of the
adjustment arm 20b has articulated on it one of the ends of an adjustment bar
21b which is connected to the height-ad~ustment elements for the bogies 8a and
8b, as will be described in the following relative to Figures 2 and 3.
Figure 2 shows how the bogie is connected to the frame of the
central section 3. Each bogie 8a, 8b is composed of two wheels, prefçrably
wheels with pneumatic rubber tires, the axles of which are supported at each
end by a double bogie girder 34 inside which the wheels are located. The
bogie can pivot around a bogie axle 32 on an articulated adjustment arm or
bogie arm 30, which is pivotably connected to a harrow tine axls 15 via an
articulated coupling 31. During pivoting of the articulated bogie arm 30
around the pivot articulation 31 the bogie axle 32 is displaced vertically
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and the working depth of the harrow tines can thus be adjusted in the manner
described above.
The pivoting of the articulated bogie arm 30 is realised by means
of a power source 36, such as a hydraulic jack, for example, which acts, by
means of a pivoting arm 37 and an articulated arm 38, on a control shaft 35
on the articulated arm 30. When the latter pivots, the adjustment bar 21a,
21b is displaced so that the adjustment arms 20a and 20b co-acting with it
rotate the torsion bars and the skid arms l9b and 17b, and l9a and 17a respec-
tively. The said components are arranged so that the pivots 15, 13a and
13b respectively for the harrow tines on all the secticns 3, 4a and 4b are
adjusted to the same height above the ground, that is to say, so that all the
harrow tines 14 have the same working depth.
The movement elements 30, 35, 38, 37, 36 and 2 shown in Figure 2,
together with the levers and the articulated arms (not designated) arranged on
the cross-bar 6 are such that the frame of the central section supported by
the wheel bogies 8a and 8b, together with the towing eye 39 on the tow-bar, are
displaced parallel with the ground in a way which is known per se during adjust-
ment in the height direction.
Figure 2 also shows the adjustment device for the angular position
of the harrow pivots. The rear pivot 15 for the harrow tines is actuated by ;
an adjustment device 40 by means of an adjustment arm 26. All~the pivots
for the harrow tines have similar adjusting arms, which are interconnected via
an element 27 in such a way that all the pivots for the harrow tines are
obliged to take up the same angular position within the secti`on.
; Figure 3 shows how displacement of the adjustment bar 21b causes
the adjustment arm 20b, the torsion bar l9b and the arm 17b to rotate. The
bar 12b of the external section, the skid 16b and the arms 17b and 18b form
a parallelogram system such that the frame of the external section moves
parallel vertically to the ground. In this way, all the pivots for the harrow
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tines are the same height above the ground. In addition, due to the connect-
ing elements 17b, l9b, 20b, 21b, 33 and 30, the harrow pivots 15 of the central
section 3 as well as the harrow pivots 13a and 13b of the external sections 4a
and 4b are the same height above the ground, since the devices described above
for one of the external sections are provided in an identical manner, but re-
versed, on the other external section.
Figure 3 also shows how the ad~ustment device 40b makes it possible
to adjust the angular position of the pivots 13b for the harrow tines on an
external section 4b. Thearrangement corresponds exactly to the preceding one
for the central section 3. Figure 3 also shows how the harrow tine 14 is
arranged relative to the pivot 13b for the harrow tines, as well as its
mounting on it. All the harrow tines 14 are fixed in the same way on their
respective pivots, that is to say, on the pivots 15, 13a and 13b.
All the pivots for the harrow tines on all the sections have
been described above as to the way in which they are ad~usted to the same
height above the ground by the linking of the ad~ustment devices of the vari-
ous sections by means of the appropriate devices, this being in the described
embodiment the adjustment bars 21a and 21b arranged on the pivoting articula-
tions 5a and 5b between the sections 3, 4a and 4b and thus the adjustment arms
20a and 20b co-acting with them. Figures 2 and 3 show how it is possible in a
corresponding manner to connect by means of suitable components the elements
26, 27; 27a and 27b for the pivoting of the pivots for the harrow tines so that
all the pivots for the harrow tines on all the sections of the harrow are ~-
sdjusted to the same angle and so that therefore all the harrow discs are
adjusted to the same effective angle in the ground.
To ad~ust the angular position of the pivots for the harrow tines,
it is possible to use an arrangement corresponding to the arrangement 40 or
; 40b shown in the Figures. If necessary, this arrangement is located preferably
at a suitable place on the central section from whence the adjustment movement
causes the pivots for the harrow tines on the external section to take up the
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1~68
desired angle by means of movement transmission elements. If the adjustment
calls for considerable force, this adjustment movement may also be effected by
means of a power arrangement corresponding to the hydraulic jack 36 for the height
adjustment. If the power source for the two adjustment arrangements is hydraulic
the vertical and angular adjustment of the pivots for the harrow tines may be
effected from the cab of the tractor driver, which provides maximum convenience.
To regulate the adjustment devices on adjoining sections of the same
unit relative to one another for example so that the pivots for the harrow tines
of the two sections may be adjusted to the same height or to the same pivoting
angle, it is possible to provide means for pre-adjustment in the elements which
transmit the adjustment movement between the sections. Figure 3 shows how
a turnbuckle 25b has been provided in the bar 21b for this purpose, to extend
or shorten the latter, which makes it possible to modify the relative
height of the pivots of harrow tines on adjacent sections.
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