Note: Descriptions are shown in the official language in which they were submitted.
CA 02299736 2000-02-29
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SEED OPENER WITH IMPROVED PRESS WHEEL ATTACHMENT
Field of the Invention
The present invention relates to a conventional or
minimum till seed opener for use with a seed drill in which
the seed opener has a trailing press wheel attached to a
press wheel frame. The press wheel frame is pivotally
attached to a seed opener frame, which, in turn, in
pivotally attached to the seed drill main frame. Constant
downward pressure is applied to the press wheel frame via a
down pressure rod and spring extending between the press
wheel frame and the drill frame.
Back9~round of the Invention
Agricultural seed drills are typically equipped with
seed openers in the form of single or pairs of cutting
discs or opener blades which open the soil immediately
ahead of a seed tube drop. The opener blades form a seed
furrow into which the seeds are dropped and a trailing
press wheel covers the seed furrow and seeds. The press
wheel is typically connected to a press wheel frame which
is pivotally attached to the opener frame such that the
angle between press wheel frame and seed opener frame is
selectively adjustable. This allows the press wheel to act
as an adjustable depth gauge for setting the depth at which
the seed opener runs.
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Examples of prior art seed openers and attached press
wheels are found as early as 1904 in U.S. Patent No.
778,123 to W. Fetzer. A more modern version is taught in
U.S. Patent No. 4,116,140 to Joseph Anderson et al. Many
other examples are found in the patent literature.
A problem common with each of these prior art seed
openers and press wheels is the linkage between the press
wheel frames and the seed opener frames when the seed
opener blade or blades encounter a hard object, such as a
rock. When the opener blades) ride up and over the
obstacle in typical seed drills, the press wheel frame is
lifted up as well. This causes the press wheel to lose
contact with the soil for the interval of time that the
seed opener blade is elevated. This results in poor seed
coverage and resultant poor seed germination in the area
immediately behind the obstacle where seeds have already
been dropped. Furthermore, down pressure on the seed
opener frame is typically provided by a down pressure
spring extending between the seed drill main frame and the
opener frame. This results in extremely high loads on the
opener blades as they trip up and over an obstacle due to
the simultaneous upward pressure applied by the obstacle
countered by the down pressure provided by the spring.
This causes rapid opener blade and bearing failure.
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It is clear then, that an improved arrangement is
needed between seed drill openers and attached press
wheels. Preferably, the press wheel should be attached in
such a manner as to keep the press wheel on the ground,
with downward pressure applied thereto, even when the
opener blades) encounter and ride up and over an obstacle.
Furthermore, such an improved arrangement should minimize
opener blade and bearing stresses and loads when the opener
blades) encounter such an obstacle.
Summary of the Invention
The present invention is directed to a seed opener for
use with a seed drill in which the seed opener has a
trailing press wheel attached to a press wheel frame. The
press wheel frame is pivotally attached to a seed opener
frame, which, in turn, is pivotally attached to the seed
drill main frame. The angle of attachment between the
press wheel frame and the seed opener frame is adjustable
to allow the press wheel to be used as a depth gauge for
the opener blade or blades. Constant downward pressure is
applied to the press wheel frame via a down pressure rod
and spring extending between the press wheel frame and the
drill frame. The use of down pressure on the press wheel
frame allows the press wheel to maintain ground contact,
with downward pressure, at all times, even when the opener
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blades) encounter an obstacle. In addition, by placing
downward pressure on the press wheel frame instead of the
opener frame, the load on the opener blades) is minimized
even when they encounter, and ride up and over, a fixed
obstacle such as a rock.
Objects and Advantages of the Invention
The principal objects of the present invention
include: providing a seed opener with improved press wheel
attachment; providing such a seed opener in which a press
wheel frame is pivotally attached to an opener frame such
that the angle therebetween is adjustable; providing such a
seed opener in which a down pressure rod and spring are
attached between a seed drill main frame and the press
wheel frame so that downward pressure is applied to the
press wheel at all times; providing such a seed opener in
which the constant downward pressure on the press wheel
frame allows it to maintain contact with the ground, under
downward pressure, for maximum seed covering and
germination; providing such a seed opener in which impact
load and resulting wear on opener blades) and bearings is
minimized when the blades) contact a fixed obstacle; and
providing such a seed opener which is strong and durable
and which is particularly well adapted for .its intended
purpose.
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Other objects and advantages of this invention will
become apparent from the following description taken in
conjunction with the accompanying drawings wherein are set
forth, by way of illustration and example, certain
5 embodiments of this invention.
The drawings constitute a part of this specification
and include exemplary embodiments of the present invention
and illustrate various objects and features thereof.
Brief Description of the Drawings
Fig. 1 is a side elevational view of a first prior art
seed drill frame, seed opener and press wheel and frame.
Fig. 2 is a side elevational view of a second prior
art seed drill frame, seed opener and press wheel and
f rame .
Fig. 3 is a side elevational view of a seed drill
frame, seed opener and press wheel and frame in accordance
with the present invention.
Fig. 4 is a side elevational view of the seed drill
frame, seed opener and press wheel and frame of Fig. 3,
illustrating the motion as a seed opener blade encounters a
buried obstacle.
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Detailed Description of the Invention
As required, detailed embodiments of the present
invention are disclosed herein, however, it is to be
understood that the disclosed embodiments are merely
exemplary of the invention, which may be embodied in
various forms. Therefore, specific structural and
functional details disclosed herein are not to be
interpreted as limiting, but merely as a basis for the
claims and as a representative basis for teaching one
skilled in the art to variously employ the present
invention in virtually any appropriately detailed
structure.
Referring to the drawings, and more particularly to
Figs. 1 and 2, two different prior art seed openers and
press wheels are illustrated, along with the actions of the
components as the opener blade encounters an embedded rock
1.
Referring to Fig. 1, a seed drill frame 2 mounts a
seed hopper 3 which meters seeds through a drop tube 4 to
an outlet position 5 immediately behind the leading edge of
an opener blade 11. The opener blade 11 is mounted on a
seed opener frame 12 which is, in turn, pivotally attached
to the seed drill frame 2 at a pivot point 13. A trailing
press wheel 14 is attached to a press wheel frame 15, which
is, in turn, attached to the opener frame 12 at a pivot
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point 21. The angle between the press wheel frame 15 and
the opener frame 12 is adjustable via an adjustable link
arm 22 to adjust the depth at which the opener blade runs.
A downward pressure rod 23 extends, at an upper end,
through an extension bracket 24 of the drill frame 2 and is
attached, at a lower end, to the opener frame 12, with a
downward pressure spring 25 positioned surrounding the rod
23 to place constant downward pressure on the rod 23, and
thus on the opener blade 11 and the press wheel 14.
When the opener blade 11 encounters the embedded rock
1, it is forced up and over the rock 1, forcing the
downward pressure rod 23 upward through the bracket 24
against the action of the downward force spring 25 and
lifting the press wheel 14 entirely off of the ground
surface. This means that the seed furrow formed for
several inches behind the rock 1 is not engaged by the
press wheel 14, and thus poor seed covering and germination
results. In addition, the loading forces on the opener
blade 11 and its bearings are considerable since all upward
motion against the downward pressure spring 25 translates
directly through the opener blade 11.
Fig. 2 illustrates a different prior art seed opener,
again in which a seed drill frame 31 mounts a seed hopper
32 which meters seeds through a drop tube 33 to an outlet
position 34 immediately behind the leading edge of an
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opener blade 35. The opener blade 35 is mounted on a seed
opener frame 36 which is, in turn, pivotally attached to
the seed drill frame 31 at a pivot point 41. A trailing,
castering press wheel 42 is attached to a press wheel frame
43, which is, in turn, attached to the opener frame 36 at a
pivot point 44. The angle between the press wheel frame 43
and the opener frame 36 is adjustable via an adjustable cam
45 to adjust the depth at which the opener blade 35 runs.
A downward pressure rod 51 extends, at an upper end,
through an extension bracket 52 of the drill frame 31 and
is connected at a lower end to the pivot point 44, with a
downward pressure spring 53 positioned surrounding the rod
51 below the bracket 52 to place constant downward pressure
on the rod, and thus on the opener blade 35 and the press
wheel 42.
In the Fig. 2 embodiment, when the opener blade 35
encounters the embedded rock 1, it is forced up and over
the rock 1, forcing the downward pressure rod 51 upward
through the bracket 52 against the action of the downward
force spring 53. Due to the release action of the
adjustment cam 45, and the pivoting connection between the
press wheel frame 43 and the opener frame 36 at the point
44, the press wheel 42 is allowed to maintain contact with
the ground surface. While this is an improvement over the
Fig. 1 embodiment, there is virtually no downward pressure
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on the press wheel 42 at this point, so seed covering and
germination still suffers in the area immediately ahead of
the rock 1. In addition, the loading forces on the opener
blade 35 and its bearings are still considerable since all
upward motion against the downward pressure spring 53
translates directly through the opener blade 35.
Referring to Figs. 3 and 4, the inventive seed opener
with improved press wheel attachment is illustrated. The
inventive seed opener and press wheel is similar in many
respects to the prior art embodiment of Fig. 2, and
similarly includes a seed drill frame 61 which mounts a
seed hopper 62 which meters seeds through a drop tube 63 to
an outlet position 64 immediately behind the leading edge
of an opener blade 65. The opener blade 65 is mounted on a
seed opener frame 71 which is, in turn, pivotally attached
to the seed drill frame 61 at a pivot point 72. A
trailing, castering press wheel 73 is attached to a press
wheel frame 74, which is, in turn, attached to the opener
frame 71 at a pivot point 75. The angle between the press
wheel frame 74 and the opener frame 71 is adjustable via an
adjustable cam 81 to adjust the depth at which the opener
blade 65 runs.
The inventive embodiment differs from the prior art in
the placement of a downward pressure rod 82 which extends,
at an upper end, through an extension bracket 83 of the
~
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drill frame 61 and is attached, at a lower end, directly to
the press wheel frame 74, with a downward pressure spring
84 positioned surrounding the rod 82 below the bracket 83
to place constant downward pressure on the press wheel
5 frame 74, and thus the press wheel 73. Downward pressure
on the opener frame 71 and the opener blade 65 is provided
through the link~between the press wheel frame 74 and the
opener frame 71.
As illustrated in Fig. 4, when the opener blade 65
10 encounters the embedded rock 1, it is forced up and over
the rock 1, causing the adjustment cam 81 to release or
trip momentarily and allowing the opener frame 71 to pivot
upward relative to the press wheel frame 74. At the same
time, constant downward pressure is still applied to the
press wheel frame 74 by the downward pressure spring 84
forcing the downward pressure rod 82 downward against the
press wheel frame 74. Thus, the press wheel 73 is in
constant ground contact, with downward pressure applied
thereto, which results in a furrow which is consistently
covered and pressed, even up to and including the area
immediately surrounding the rock 1. This results in
improved seed coverage and germination due to the constant
contact and pressure between the press wheel 73 and the
ground. In addition, the life of the opener blade 65 and
associated bearings is greatly improved since most of the
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impact load between the rock 1 and the opener blade 65 is
immediately absorbed by the trip action of the adjustment
cam 81. In other words, the opener blade 65 is not
sandwiched between the downward pressure of the downward
pressure spring 84 and rod 82 and the upward force
generated by the encounter with the rock 1, as is the case
in the prior art embodiments of Figs. 1 and 2.
While the invention has been illustrated as a single
seed opener and press wheel, it should be apparent that the
invention is typically used on larger seed drills which
include multiple seed openers and associated press wheels.
The opener blade 65 has been described in the singular, but
it should be clear that tandem opener blades are equally
usable with the inventive press wheel attachment. The
downward pressure rod 82 and spring 84 are just one
mechanism for providing downward pressure directly to the
press wheel frame 74. Other downward pressure mechanisms,
e.g. hydraulic springs, shock absorbers, etc., could be
used effectively as well. It is thus to be understood
that while certain forms of the present invention have been
illustrated and described herein, it is not to be limited
to the specific forms or arrangement of parts described and
shown.
