Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to a tilling blade
mounting assembly for use on a plow which is particularly
- intended for woodland tilling. Such a plow has a frame and
tilling blades, the-plow being provided with means for
adjusting each blade to a predetermined angular position
with respect to the direction of displacement of the plow.
Each tilling blade is mounted for rotation on a base part which
is swingably and resiliently mounted on the frame whereby to
allow the blade to avoid obstacles on the ground and resiliently
return to its predetermined angular position.
In presently known plows intended for use in wood-
land tilling, the shaft carrying the tilling blade is attached
either directly to the frame of the plow or to one end of an
angularly extending component rotatably mounted on the plow
frame. Plows of this type are known wherein it is possible,
ln order to provide appropriate positioning of the tilling
blades, to turn the angularly disposed component to the desired
angle and thereafter hold on to this position by connection
with a lever and pin arrangement. Whenever the tilling blades
meet an obstacle, such as a stone, they must be able to change
their angular position in order to move around the obstacle.
In order to accomplish this, the lever and pin arrangement have
been supplemented with sprlngs which allow the required change
in the angular position of the tilling blade when meeting an
obstacle and which, thereafter, automatically return the tilling
blades to their initially adjusted position.
The aforesaid plow is of the type described in my
previous Finnish patent No. 56,762, granted on April 10, 1980,
and the instant invention is an improvement thereof. In my
prior Finnish patent, there is disclosed a mounting assembly
including adjusting and springing means for the tilling blades
wherein the tilling blades may be accurately adjusted in
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position in order to provide an adequate work in various
types of soil, the mounting means comprising an adjustment
part whereby the tilling blades are first roughly adjusted
into the desired angular position and a fine adjustment part
by means of which the tilling blades are adjusted to an exact
and final angular position, the angularity being with respect
to the displacement of the plow.
In the plow described in the aforesaid Finnish
patent, the tilling blades are secured to a shaft which is
rotatable in a housing or base rotatably attached to the frame
of the plow. The attachment of this base or frame is by means
of an upwardly extending and essentially vertical shaft to one
end of which the base or housing is secured as by welding, the
other end of the shaft being secured to an adjustment disc or
flange for the coarse angular adjustment of the tilling blade.
Although the adjusting and springing means in the
plow in the aforesaid Finnish patent adequately meets the
required resilient properties, it has however been found that
the attachment of the base or housing to the vertical shaft
often breaks where particularly difficult conditions of stony
soil are met. With the present trend towards greater tilling
width and depth, stiffer springs are needed in the springing
means so that the attachment of the base or housing is
subjected to greater risk of failure than normally.
The object of the present invention is therefore to
provide a tilling blade mounting assembly for a plow of the
aforesaid type wherein the strength of the assembly is
increased so that it is less prone to fail. With the tilling
blade mounting assembly in accordance with the present
invention, the tilling width may be appreciably increased and
over-sized tilling blades used and therefore greater tilling
depth available than the earlier known plows.
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Accordingly, there is provided and broadly claimed
herein a tilling blade mounting assembly for a plow having a
frame and tilling blades, the plow being provided with means for
adjusting each blade to a predetermined angular position with
respect to the direction of displacement of the plow, wherein
each tilling blade is mounted for rotation on a base part, the
base part keing swingably and resiliently mounted on the frame
whereby to allow the blade to avoid obstacles on the ground
~ and resiliently return to the predetermined angular position.
This assembly is essentially characterized in that the base
part is secured to and between adjacent ends of a pair of
upwardly extending coaxial shafts of which the other ends are
rotatably mounted on the frame.
In a preferred embodiment of the invention, the base
part is a housing into which is received a rotary axle at one
end of which the tilling blade is removably fixed, the housing
- having a longitudinal axis which extends transversely of the
axes of the coaxial shafts. Also, the upper end of the upper
one of the upwardly extending shafts may be connected to the
blade angular adjusting means.
The frame may also include a pair of spaced
horizontal plates, the aforesaid coaxial shafts being then
mounted on and between the said plates for rotation.
An embodiment of the invention will now be described
with reference to the appended drawings wherein:
Fig. 1 is a perspective view of a plow as disclosed
in the aforesaid Finnish patent;
Fig. 2 is a side elevation view of a tilling blade
mounting assembly made according to the invention, and
Fig. 3 is a perspective view of two assemblies such
as shown in Figure 2, mounted on a forest plow.
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Fig. 1 shows a known forest plow 1 having at either
end a tilling blade mounting assembly including blade
adjusting and springing means suitable for coarse and fine
adjustments. The part for coarse adjustment comprises,
secured to the upper end of a vertical shaft 3, an adjustment
disc or flange 4 pierced with evenly spaced holes and a fork 5
secured to the adjusting disk 4 by means of a pin (not shown)
extending through the fork and through any one of the holes
of the adjusting disc 4. Secured to the lower end of the
vertical shaft 3, as by welding, is a housing 6 in which an
inclined shaft (not shown) is received. The inclined shaft
is rotatable in the housing 6 and is provided, at one end,
with a perforated flange 7 serving for the removable mounting
blade or disc, as by means of bolts. The housing 6 together
with its inclined shaft constitutes a rotatable base part.
Resilient means tnot shown) is provided at the end of an arm 8
~extending from the fork 5. This resilient means is disposed
within a housing 9 and is of course intended to produce a
desired spring effect to bias the tilling blade to a return
position. Fine adjustment of the tilling width of the blade
is achieved by rotation of a nut 10, on a threaded extension
of the arm 8, the adjustment being secured by a lock nut 11.
The operation of the aforesaid tilling mounting
assembly of Figure 1, including the adjusting and springing
means, is as follows. The toe-in angle of the tilling discs
is first coarse-adjusted by swivelling the disks to lie
approximately at the desired predetermined angle and swivelling
the fork 5 to the adjustment disc 4 by inserting the not
shown pin in the nearest hole of the adjustment disc 4. Final
fine adjustment of the toe-in angle is obtained by turning
the adjustment nut 10 and fixing it by the lock nut 11.
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With the blade mounting assembly including the
adjusting and springing means of Figure 1, obstacles met in
normal practice are avoided. It may however occur, in difficult
ground conditions that,in spite of a tilling blade swivel-
ling, at the obstacles, the tilling flange,housing 6 and
vertical shaft 3 be additionally subjected to important bending
stresses such that the vertical shaft 3 or its attachment
to the housing 6 may break.
Referring now to Fig. 2, there is shown a tilling
blade mounting assembly including adjusting and springing means
according to the present invention, for use on a forest plow
or the like, which tends to avoid the drawback mentioned above.
As taught by the present invention, the vertical shaft conslsts
of two spaced and mutually aligned, i.e. coaxial, vertical
shafts 3A and 3B secured, as by welding, to the housing 6. The
shafts 3A and 3B are rotatably mounted at their other ends to
frame plates 12. To the top end of the shaft 3A, there is
secured, as by means of a key, an adjustment disc or flange 4
which is like the one shown in Fig. 1. The frame plates 12 may
be structures integrally associated with the forest plow 1 or
they may be removably fixed with bolts to the frame part proper
of the forest plow in which case the entire tilling blade
mounting assembly with its tilling discs is easily removable
from the plow, for servicing for instance.
Fig. 3 shows the tilling blade mounting assembly of
Fig. 2, with its adjusting and springing means, mounted on a
conventional forest plow. The construction of Figures 2 and 3
is quite sturdier than the construction of the prior art shown
in Fig. 1 and in my Finnish patent No. 56,762 because the
bending stresses are distributed between two vertical shafts
3A and 3B, and they are not directed to one end of a single
vertical shaft, as in the construction of Fig. 1. As a
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consequence, the tilling width may be considerably increased
as well as the tilling depth by using larger size tilling
discs. At the samé time, the height of the structure of the
whole forest plow may be reduced and its centre of gravity
lowered.
A tilling blade mounting assembly and its adjusting
and springing means made according to the invention may
naturally also be provided with other types of coarse or fine
adjustments. Also, the invention is not restricted to the
mounting of disc-shaped tilling blades on a forest plow as
other types of tilling members known in the art may be mounted
on a forest plow in the manner taught by the present
invention.
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