Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
BACKGROUND OF T~E INVENTION
This invention relates to new and useful improve-
ments in harrow sections normally used in preparing the ground
for seeding.
Conventionally, such sections include a plurality
of teeth depending downwardly from a frame, with the frame
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being pulled behind a source of power such as a tractor or the
like.
These sections are normally relatively lightweight
and are provided with fixed teeth so that if a stone or other
obstruction is engaged by one of the teeth, the frame is bucked
up out of the ground and sometimes tossed onto adjacent harrow
sections resulting in broken teeth, bent teeth and damaged har-
row frames.
Another disadvantage with conventional harrow sections
is the fact that when working in trash or soft soil, the angle
of the teeth cannot be varied so that the harrow sections plug
up relatively easily.
SUMM~RY OF THE INVENTION
The present invention overcomes these disadvantages
firstly by providing a relatively heavy harrow section and sec-
ondly, by providing mounting bars for the teeth which are mount-
ed for rotation within the frame and are normally held by spring
pressure in a fixed position. However, if any one of the teeth
encounters an obstruction, the tooth is moved rearwardly against
pressure of the spring which immediately returns the harrow teeth
to the engaged position once the obstruction is passed.
One aspect of the invention consists of a harrow section
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comprising in combination a substantially rectangular frame,
a plurality of harrow tooth bars mounted for partial rota-tion
in spaced and parallel relationship transversely of said frame,
a plurality of harrow teeth secured to and depending from each
harrow tooth bar, lever means extending upwardly from each of
said bars, spring means extending between said lever means and
said frame normally urging said teeth in the direction of travel,
and means to limit the movement of said lever means in the di-
rection urged by said spring means.
A still further object of the invention is to provide
a device of the character herewithin described which is simple
in construction, economical in manufacture and otherwise well
suited to the purpose for which it is designed.
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With the foregoing objects in view, and other
such objects and advantages as will become apparent to
those skilled in the art to which this invention relates
as this spscification proceeds, my invention consists es-
sentially in the arrangement and construction of parts allas hereinafter more particularly described, reference be-
ing had to the accompanying drawings in which:
BRIEF DESCRIPTION ~ THE DRAWINGS
Figure l is a top plan view of a harrow section
incorporating the invention.
Figure 2 is a side elevation of Figure l,
Figure 3 is an enlarged fragmentary side eleva-
tion showing the spring mounting for the rearmost tooth
bar,
Figures 4, 5, 6 and 7 are enlarged fragmentary
side elevations showing the four positions of the block
controlling the angle of inclination of the harrow teeth.
In the drawings like characters of reference in-
dicate corresponding parts in the different figures.
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DETAILED DESCRIPTION
Proceeding therefore to describe the invention
in detail, reference should first be made to Figures 1
and 2 in which the harrow section includes a substantially
rectangular frame 10 comprising a pair of spaced and paral-
lel longitudinal members 11 bolted or otherwise secured tofront and rear cross members 12 and 13, Diagonal braces
14 extend between the front member and the side members 11
to stiffen the frame structure,
A pair of spaced and parallel angle irons 15 are
supported upon upstanding brackets 16 and are positioned
centrally of the frame 10 and between the longitudinal :
side members 11 and these two angle irons act as guides
as will hereinafter be described,
Tubular bearing shells 17 are secured to the un-
derside of the side members 11 and act as bearings forharrow tooth bars or rods 18 which extend transversely
of the frame in spaced and parallel relationship with
the ends staggered as illustrated to allow for complete
coverage when a plurality of harrow sections is pulled
behind a harrow draw bar in the usual manner,
Harrow teeth 19 extend downwardly through aper-
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tures within the bars 18 and are conventional in construc-
tion.
The bars, which are partially rotatable within the
bearing shells 17, are each provided with an upstanding
lever arm 30 secured by the lower end thereof to each of
the bars and extending upwardly between the aforementioned
guides 15.
A tension spring 21 is secured by one end thereof
to the lever arms 20 and by the other end thereof to an ad-
justing nut and bolt assembly 22 which engages an eye or
bracket 23 depending downwardly from the guides 15 so that
the tension of the springs 21 can be adjusted within limits.
In this embodiment, a lug 21A bolted or otherwise secured to
lever arm 20 receiving one end of spring 21. These springs
21 normally maintain the lower ends of the teeth 19 in the
direction of travel 24 and the forward movement of these
lower ends (and of course the rearward movement of the upper
ends of levers 20) is limited by means collectively designat-
ed 25 and shown in detail in Figures 4 through 7.
Means 25 takes the form of a rectangular block
secured to the guide 15 by means of a bolt 27 and it will
be noted that the point of connection of the block to the
guide is offset relative to the longitudinal and transverse
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axes 28 and 29 respectively of the block as shown in Figure
7. This means that when the block is positioned as shown
in Figure 4, the lever arm 20 is vertical to the horizontal
so that the teeth are at 9~ to the horizontal.
If the block 26 is turned to the position shown
in Figure 5, then the angle between the lever and the hori-
zontal is lO0 as shcwn and if the block is turned as shown
in Figure 6, then this angle is llO .
Figure 7 shows the extreme position with the lever
at 120 from the horizontal.
As the lever is moved due to the positioning of
block 26, so of course are the teeth 19 which incline rear-
wardly relative to the direction of travel as shown in phan-
tom in Figure 2 and these various positions are chosen de-
pending upon the condition of the ground being worked.
For example, with relatively soft soil or trash cover, the
angle is increased so that the teeth trail thus preventing
the devices from plugging.
Figure 3 shows the spring connection for the rear-
most lever specifically designated 20A which is connected
to the tooth bar specifically designated 18A because of
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the lack of room for anchoring the spring in the method
hereinbefore described~
A bar 30 extends forwardly from the lever 20A and
one end of the spring 21 is anchored to the distal end of
this bar and to the anchoring means 23 similar to that
hereinbefore described.
Reference to Figure 1 will show that the position
of the individual teeth 19 of the rearmost tooth bar 18A
is such that it forms a furrow intermediate the furrows
formed by the teeth of the next adjacent tooth bar spaci-
fically designated 18B and the further bar specifically
designated 18C and this furrow formation has been found
of value to prevent soil drifting and the like.
Because the harrow sections are relatively heavy
compared to conventional sections, it is desirable that
they be utilized with hydraulic harrow draw bars and in
this connection, apertures 31 are formed through the longi-
tudinal members for attachment to conventional hydraulic
draw bars.
Finally, additional braces 32 are provided extend-
ing from the side members 11 diagonally inwardly and upward-
ly to be attached to the guide members 15 in order to steady
same.
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Since various modifications can be made in my
invention as hereinabove descri.bed, 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 illus-
trative only and not in a limiting sense.
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