Note: Descriptions are shown in the official language in which they were submitted.
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PROGRESSIVE CONCAVE
FIELD OF THE INVENTION
The present invention relates to grain harvesting machines and, more
particularly, to the concave section of the harvesting machine where grain is
separated from the stock.
BACKGROUND OF THE INVENTION
This invention relates to a combine in which one or more rotors or
contacting concaves are mounted longitudinally of the axis of the combine.
Combines
of this type are relatively expensive and especially in order to justify a
substantial
investment in a combine, it is desirable that the same be capable of
harvesting a
relatively wide variety of crop products efficiently. Concaves employed in so-
called
universal type combines of the kind referred to comprise a series of bars
which
extend longitudinally in the threshing compartment of the combine and a series
of
longitudinally spaced curved rods extend transversely through said bars to
provide
openings through which threshed material passes and is received by a grain pan
beneath the concave, said pan discharging onto a suitable sieve unit incident
to
completing the separation of the product material from chaff and other waste
material.
Several downsides occur because of the present art forms of concaves.
These faults are a slowing of the material especially in high moisture or
other less
than ideal conditions such as greater leaf material, higher crop yields and
wear of the
machine parts. These faults result in more grain damage, greater grain loss
through
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the waste material ejection system on the combine and greater fuel
consumption. In
addition down down is often incurred by the operator in attempts to unplug the
harvesting machine when large material flows cause the separation system to
plug
up shutting down all harvesting processes until the situation can be remedied.
Not
only is economy adversely effected from a quantitative and qualitative point
but fuel
consumption is increased, possible damage from deteriorating weather
conditions is
increased as is the safety of the operator engaged in the unplugging of the
machine.
Recently the advent of pharmaceutical harvesting of grains has
increased the need for gentle harvesting techniques. Pharmaceutical harvesting
refers to the growing or crops for removal of particular germs, cells or
components for
use in the pharmaceutical industry. However such harvested grain is held to
higher
standards of quality control than food or feed grains are held to, thus upping
the
requirement for less damage to the kernel during harvesting.
Manufacturers have sought to solve this issue since the first combine
was manufactured and have used a variety of means to deal with the issue. One
solution is to reverse the direction go the feeding mechanism, pulling the
plugged
material back from the direction it came in.
Another solution attempt is made by increasing the rotational speed of
the rotor to force the material through the separation unit.
Twin rotors are yet another example in known art of a method to
process large amounts of material through the separation system without
increasing
loss or damage to the grain.
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Neihaus, U.S. Patent No. 4,499,908, developed an inwardly interior flat
surfaced concave to eliminate the catching of crop materials.
Rowland-Hill, U.S. Patent No. 4,031,901 provides for rotatable sleeves
that rotate over the arcuate rods of the concave in an attempt to facilitate
the
passage of threshed crop material through the openings in the concave to
reduce
crop damage. Other U.S. Patents by Rowland-Hill relating to combine harvesters
include 3,742,686, 3,696,815 and 3,631,862.
Kuchar, U.S. Patent No. 4,909,772 provides for more bars in the
concave to permit a reduced rotational speed of the cylinder thus reducing
crop
damage in the separation mechanism.
Peiler, U.S. Patent No. 4,330,000, received a patent for the ability to
have adjusting linkage enabling the operator to change the distance
relationship
between the concave and the cylinder.
Williams, U.S. Patent No. 4,284,086 attempted to clean the cylinder
concave area with air pressure to d=reduce clogging and build up of material.
Glaser, U.S. Patent No. 4,258,726 used vanes to direct the crop into
various portions of the separation mechanism to reduce clogging and damage.
Johnston, U.S. Patent No. 4,222,395 used protruding fingers that were
either mechanically adjusted or remotely adjusted to control the flow rate
through the
separation mechanism.
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Ausherman, U.S. Patent No. 3,927,679 used an elevated sharpened
raspbar fin to "cut' through the crop material forcing it though the
separation
mechanism.
Knap, U.S. Patent No. 3,568,682 describes a grate to be placed under
the separation mechanism that crop material will pass over.
Gerhardt, U.S. Patent No. 3,552,396 uses a hydraulic cylinder to adjust
the concave spacing relationship with the cylinder.
Johnson, U.S. Patent No. 2,457,680 used an inwardly zigzag
configuration on his concave design to provide for a more efficient means of
threshing grain.
Plugged material removal from a reversal of the direction of the
mechanical components that created the plug don't always work and when they
don't
can damage parts of the machine increasing downtime and repair costs. They
also
do not then properly process the crop in a manner that provides with a
quantitative or
qualitative product.
In order to prevent foreign material from clogging the concave, some
combine manufacturers have increased the rotational velocity of the cylinder
in an
attempt to force the foreign material through the apertures in the forward
portion of
the concave and to maintain these apertures open. However, increasing the
rotational velocity of the cylinder increases the likelihood of damage to the
harvested
crop. This damage is caused by increased impact forces as the faster cylinder
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contacts the separated grain and appears as cracking making the grain more
susceptible to infestation and deterioration.
Increasing the rotational velocity of the cylinder also causes more of the
crop residue, which is displaced along the concave, to be recirculated by the
cylinder
5 rather
than being discharged from the aft, upper edge of the concave. Backfeeding of
the crop residue, or its recirculation about the rotating cylinder, reduces
the
combine's capacity to separate the grain from the plant residue resulting in
reduced
recovered yields and greater likelihood of residue clogging of the concave.
Finally,
operating the cylinder at increased rotational velocities increases the
combine's fuel
consumption rate and is thus less fuel efficient. Forcing material through the
separation unit of the machine only increased the damage done to the grain
portion
of the crop resulting in a lower or no value product such as for
pharmaceutical
harvesting where the grain must be held to a much higher quality than food
quality
grains are held.
Twin rotors increase the cost of manufacturing substantial as well as the
cost of maintenance in parts and labor, now the operator has two separation
systems
to be concerned with and to clean and maintain.
Changing the distance relationship between the cylinder and the
concave does not reduce damage. Decreasing the distance creates a plugging
effect
and increasing the distance results in unthrashed crop material passing
through the
separation mechanism.
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Smooth surfaces further defeat the purpose by eliminating much of the
frictional area that the concave proposes to provide as a means of removing
the seed
heads or grain from the stocks or leafy material.
It would be desirable to decrease damage caused to crops as the result
of separation and thrashing.
It would also be desirable to reduce operator expense by reducing fuel
consumption.
It would also be desirable to reduce operator maintenance and down
time from machine damage by reducing plugged and damaged separation units.
It would also be desirable to reduce downtime from plugged separation
units.
It would also be desirable to increase the price of the crop harvested
through a reduction in damage.
It would also be desirable to provide for faster more economical
harvesting.
It would also be desirable to reduce weather damaged crops by
increasing the speed and reliability of the harvest.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is
provided a concave which has axially extending members and circumferentially
extending members. Each of these members has a flat interior surface presented
toward the rotor. The flat surfaces of the axially extending members are in
the same
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circular surface as the circumferentially extending members. This presents a
smooth
grid surface which faces the rotor. The axially extending members have a
progressively larger spacing for the first portion of their section. Beginning
with the
greatest spacing toward the direction material enters the concave and an
increasingly
smaller spacing away from the opening until they reach a uniform spacing for
the
remainder of the concave unit. This results in better retainage of the
vitamins,
minerals and enzymes within the grain.
In accordance with another aspect of the invention, for use in a combine
harvester with a rotating cylinder having a plurality of raspbars mounted in a
spaced
manner about the periphery of said cylinder for separating grain from the
leafy portion
of a plant, a concave comprising:
first and second end brackets each adapted for mounting to respective a
respective inner wall of the combine and including a respective lower leading
edge
and a higher trailing edge, wherein each of said brackets forms a circular arc
between
the leading and trailing edges thereof;
a plurality of longitudinal crossbars coupled at respective ends thereof to
said
first and second end brackets and spaced apart from one another from the lower
leading edge to the higher trailing edge of each of said end brackets, the
longitudinal
crossbars being progressively spaced apart such that spacing between said
elongated crossbars decreases in a direction moving from the lower leading
edge of
each end bracket to the higher trailing edge thereof; and
arcuate rods that are longitudinally spaced apart from one another and
coupled to the crossbars in positions lying transversely thereto between the
end
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brackets, and that are flush with upper edges of both the end brackets and the
longitudinal crossbars.
In one embodiment, the spacing between the longitudinal cross-bars is
approximately 1-5/16 inch at a leading area adjacent the lower leading edge.
In one embodiment, the spacing between the longitudinal cross-bars is
approximately 1 inch at a trailing area adjacent the upper trailing edge.
In one embodiment, the spacing between the longitudinal cross-bars is
approximately 1-1/8 inch at an intermediate area between the lower leading
edge and
the upper trailing edge.
BRIEF DESCRIPTION OF THE DRAWINGS
A complete understanding of the present invention may be obtained by
reference to the accompanying drawings, when considered in conjunction with
the
subsequent, detailed description, in which:
Figure 1 is a partial cutaway view of an illustrating the manner in which
the improved concave invention is intended for use in a combine;
Figure 2 is a prior art view of an is a perspective view of a prior art
arrangement showing the general arrangement of a concave, a cylinder, a
beater,
and a conveyer arrangement such as employed in a typical prior art combine;
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Figure 3 is a prior art view of a sectional view of a prior art arrangement
of a concave, a cylinder, and a beater used for separating the grain-bearing
portion
of a plant from its leafy residue in a typical combine;
Figure 4 is a front perspective view of a concave in accordance with the
principles of the present invention;
Figure 5 is a cross-sectional view of an is an enlarged, partial end view
of the concave assembly illustrating the pinch point of a concave and a
cylinder used
for separating the grain-bearing portion of a plant from its leafy residue in
a typical
combine;
Figure 6 is a top perspective view of a concave of the present invention
illustrating cut away detail; and
Figure 7 is a front & side view of a preferred embodiment of an
improved progressive concave.
For purposes of clarity and brevity, like elements and components will
bear the same designations and numbering throughout the Figures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown a partially cutaway perspective view
of a typical combine 10 which incorporates a prior art cylinder and concave 24
arrangement. The combine 10 is comprised primarily of an aft separation
mechanism
12 / drive section and a forward header assembly 14 attached to a forward
portion of
the separation mechanism 12 / drive section. The combine 10 includes an
operations
platform 22 in which are positioned various operating controls for the combine
10.
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The separation mechanism 12 / drive section effects separation of the grain
from the
crop residue and includes a plurality of wheels 20 as well as a means for
propulsion
(typically a diesel engine 28 which is not shown for simplicity) for
propelling the
combine 10 through a field in harvesting the crops. The separation mechanism
12 /
5 drive section includes an aft exit end or discharge area 16 from which the
crop
residue, after the grain is separated therefrom, is exhausted from the combine
10 and
deposited in the field being harvested.
The header assembly 14 mounted to a forward portion of the separation
mechanism 12 / drive section is wider than the separation mechanism 12 / drive
10 section and includes a plurality of head units extending along the
length thereof. The
header assembly 14 may also be provided with a plurality of spaced row crop
heads
along the length thereof for harvesting soybeans, wheat, milo, rice or various
other
grain and seed crops. The heads are adapted to separate and remove the seeds
or
grains from the plant stalk. The grain and the plant residue are then
delivered to an
aft portion of the header assembly 14 and are directed to the center thereof
by means
of a conveyance mechanism. From the center, aft portion of the header assembly
14,
the grain and residue mixture is delivered to a feeder house 11 which
transports the
mixture via a conveyor to the combination of a rotating rotor 13 and a concave
24
screen. The rotor 13 includes a plurality of spaced raspbars 50 extending
along the
length and spaced around the periphery thereof. Rotation of the rotor 13
causes the
raspbars 50 to engage the grain or seed heads and separate the grain from the
leafy
portion of the plant. A beater assembly, which is not shown in the figure, is
typically
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positioned immediately aft of the rotor 13 and concave 24 screen combination
for
further carrying out the separation process. The beater assembly deposits the
reduced mixture upon an elongated chaffer sieves 15 which is comprised of a
plurality of vibrating sieves. The separated grain is allowed to fall through
the
vibrating sieves of the chaffer sieves 15, while the unwanted plant residue is
retained
on an upper portion of the chaffer sieves 15 and displaced toward the rear of
the
combine 10. The thus separated grain which falls through the vibrating sieves
of the
chaffer sieves 15 is deposited upon a cleaning shoe 17 positioned below the
chaffer
sieves 15 and comprised of a grate structure for further separating the grain
from any
crop residue remaining in the mixture. As the grain and residue mixture falls
upon the
cleaning shoe 17, a blower 19 directs an air stream on the falling mixture to
remove
chaff therefrom. The chaff and other crop residue removed from the mixture in
the
earlier separation steps are discharged from the aft or exit end of the
combine 10.
The thus cleaned grain collects in a lower portion of the separator section of
the
combine 10 and is laterally displaced by means of a rotating clean grain auger
to a
center portion of the combine 10.
The clean grain auger is coupled to and continuous with a generally
vertically oriented grain elevator. The grain elevator includes a housing
within which
is positioned a plurality of paddles attached to a moving endless chain. The
grain
elevator lifts individual portions of grain upward where the grain is then
displaced by
a loading auger into a storage bin or grain tank 18. One end of an off-loading
grain
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auger may be positioned within the storage grain tank 18 for removing the
grain
positioned therein from the combine 10.
Referring to FIG. 2, there is shown a perspective view illustrating
greater details of a prior art arrangement of a feeder house 11, a concave 24,
a
rotating cylinder 52, a rotating beater 56, and an upper auger. The cylinder
is
positioned in closely spaced relation to the concave 24 which is disposed
immediately below the cylinder and comprised of a pair of curved end brackets
54
(only one of which is shown in FIG. 2 for simplicity) and a plurality of
spaced bars 30
extending along the length thereof connected by welding or other permanent
secure
means to arcuate rods 32. The concave 24 further includes a plurality of
spaced,
curved members disposed along its length which are also not shown in the view
of
FIG. 2. As previously described, the combination of the rotating cylinder 52
and the
concave 24 effects separation of the grain from the leafy, or stock, portion
of the
plant. Disposed immediately forward of the cylinder is a conveyor-type feeder
assembly which delivers the crop directly between the cylinder and the open-
mouth
concave 24 as the cylinder rotates in the direction of the arrow in FIG. 2.
Disposed
immediately aft of the cylinder is a rotating beater 56 assembly which
displaces the
crop material and un-separated grain from the cylinder/concave 24 combination
for
further separation processing. An upper auger disposed above and slightly
forward of
the cylinder returns un-threshed grain which reaches the back of the cleaning
area to
the cylinder area for another pass between the cylinder and the concave 24.
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The cylinder shown in FIG. 2 is disclosed and claimed in Applicant's
U.S. Pat. No. 4,796,645, issued Jan. 10, 1989. The present invention is not
limited to
use with this particular cylinder, but will operate with virtually any type of
rotating
cylinder 52 intended for use in a combine 10. The cylinder includes a
plurality of hubs
60, or spiders, disposed in a spaced manner along the length thereof and
coupled by
means of an axle, or support shaft 58, inserted through a center of each of
the hubs
60. Each of the hubs 60 includes a plurality of spaced, upraised peripheral
portions
upon which are mounted raspbars 50 which extend substantially the entire
length of
the cylinder. Each of the raspbars 50 is securely mounted to an upraised
peripheral
portion of each of the hubs 60 in a spaced manner by conventional means such
as
mounting bolts 64 or the combination of a mounting bracket and a bolt, which
are not
shown for simplicity.
Positioned immediately adjacent to and attached to each of the raspbars
50 along the length thereof is a respective spacer or filler plate 44. Each of
the filler
plates extends over a portion of the gap 62 or space between adjacent raspbars
50
and is disposed over substantially the entire length of the cylinder and has a
curved
cross section. The filler plates may be securely coupled to each of the hubs
60 by
conventional means such as bolts 64.
Referring to FIG. 3, there is shown a sectional view of a portion of the
prior art concave 24, rotating cylinder 52, and rotating beater 56
arrangement. As
previously described, the rotating cylinder 52 includes a plurality of spaced
raspbars
50 disposed about its periphery, although only four raspbars 50 through are
shown in
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the figure for simplicity. The rotating beater 56 similarly includes a
plurality of spaced
wings 68, or extensions, and disposed about its periphery and extending the
length
thereof. The cylinder as well as the beater each rotate in a clockwise
direction as
shown by the direction of the arrows in the figure. The harvested portion of
the plant
including the grain and leafy portion is directed onto the lower, leading edge
of the
concave 24 by the combination of the rotating cylinder 52 and the previously
described feeder house 11 which is not shown in the figure. When engaged by
the
concave 24 as well as the raspbars 50 disposed about the rotating cylinder 52,
the
grain bearing portion of the plant, such as the corncob shown in the figure,
is urged
between the grate-like structure of the concave 24 in a downward direction.
The leafy
residue of the plant is displaced rearward and upward along the upper surface
of the
concave 24 by the rotating raspbars 50 of the cylinder. As the leafy residue
arrives at
the upper edge of the concave 24, it is positioned in the vicinity of the
rotating beater
56 which then displaces the leafy residue rearwardly over a short flat finger
grate 74.
The finger grate is positioned adjacent to the upper, aft edge of the concave
24 for
supporting the leafy residue and maintaining it in position for rearward
displacement
by the rotating beater 56. After exiting the concave 24, cylinder, and beater
assembly, the leafy residue is then further processed for the removal of
additional
grain therefrom and discharge from the combine 10.
The concave 24 includes a pair of curved brackets on each end thereof.
Each of the curved end brackets 54 is securely attached to a respective inner
wall of
the combine 10 by means of an upper mounting bolt 66 and a lower mounting bolt
70.
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Extending between and mounted to each of the curved end brackets 54 are a
plurality of linear, spaced crossbar. Each of the crossbars is further coupled
to a
plurality of spaced, curved intermediate bars 72 along the respective lengths
thereof
and to arcuate rods 32 welded into each of the cross bars 30 to secure the
spacing.
5 The combination of the crossbars and curved intermediate bars 72 forms a
grate-like
structure having a plurality of generally rectangular-shaped apertures
therein.
As shown in the figure, the curved end brackets 54 and curved
intermediate bars 72 are not formed in a true circular arc. Only portions of
each of the
curved end brackets 54 and intermediate barare formed in a circular arc. Thus,
the
10 concave 24 includes an upper generally linear portion, a lower generally
linear
portion, and an intermediate circular portion. Because only the intermediate
portion of
the concave 24 is formed in a circular arc about the rotating cylinder 52, the
cylinder's raspbars 50 and are displaced in a closely spaced, generally
parallel path
only along this portion of the concave 24. The displacement between the
cylinder's
15 raspbars 50 and the upper end portion and lower end portion of the
concave 24 is
greater than the close spacing between the raspbars 50 and the intermediate
portion
of the concave 24. In addition, the cylinder's raspbars 50 travel in a path
into, or
toward, the concave 24 adjacent to the lower portion thereof. Because the
spacing
between the cylinder's raspbars 50 and the concave 24 is not fixed, but
varies, along
these portions of the concave 24, reduced separation of the grain and leafy
residue
of the plant occurs in these areas of the concave 24. In addition, the
movement of the
cylinder's raspbars 50 into, or toward, the concave 24 adjacent to the lower
end
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thereof causes compressive forces to be applied to the grain resulting in
grain
damage and clogging of the lower, leading edge of the concave 24 with foreign
debris such as rocks and soil. Thus, the gaps between the three lowermost
crossbars
become clogged by foreign matter, preventing the passage of the separated
grain-
bearing portion of the plant therethrough. The uppermost crossbars are
ineffective in
the grain separation process because of their greater displacement from the
rotating
raspbars 50.
As shown in FIG. 3, a flat finger grate 74 is disposed adjacent to the
upper end of the concave 24. The flat finger grate 74 includes a plurality of
spaced,
cell grate 76 extending rearward from the concave 24. The bars are disposed in
a
spaced manner along the length of the concave 24, with their proximal ends
mounted
to a filler plate 44 by conventional means such as weldments. A crossbar
extends
between each adjacent pair of bars to form the finger grate. Each end of the
filler
plate 44, which also extends along the length of the concave 24, is securely
coupled
to a respective mounting bracket. Each of the mounting brackets 78 is attached
to an
adjacent inner wall of the combine 10 by means of a respective mounting pin
80. As
the leafy crop residue is displaced upward by the cylinder's rotating raspbars
50, the
finger grate is intended to provide support for the crop residue as it is
displaced
rearward by the wings of the rotating beater 56. However, because the upper
end of
prior art concaves as well as the finger grate attached thereto are disposed
directly
beneath the rotating beater 56, the crop residue is displaced to a location
directly
below and slightly forward of the beater resulting in some of the residue
being
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displaced forward of the beater and continuing around the rotating cylinder
52. This
is known as residue "backfeed" and results in the residue being recirculated
around
the rotating cylinder 52 so as to increase the likelihood of the residue
clogging the
concave 24 during its second pass, a reduction in the rate at which the
harvested
plants can be processed for grain separation within the concave 24-cylinder
combination, and imposition of a greater load on the rotating cylinder 52. In
an effort
to compensate for this increased load, some prior art combines have increased
the
rotational velocity of the cylinder but this has led to increased impact
damage to the
grain.
Referring to FIG. 4. A perspective view of a concave 24 in accordance
with the principles of the present invention. A side elevation view is shown
in FIG 5
and partial front perspective view of the concave 24 is shown in FIG. 6. The
concave
24 includes a pair of curved end brackets 54 and a plurality of linear,
elongated
crossbars extending therebetween. Coupled to and extending through the
plurality of
cross bars 30 are a plurality of arcuate rods 32 and a plurality of curved
intermediate
bars 72. The curved intermediate bars 72 are arranged in a spaced manner
between
the two curved end brackets 54 and along the crossbars. Each of the curved end
brackets 54 and intermediate bars 84 is shaped in the form of a circular arc
over the
full length thereof. Thus, the concave 24 is disposed in closely spaced,
parallel
relation to the rotating raspbars 50 of the cylinder. The upper edges of each
of the
crossbars are similarly disposed in closely spaced relation and at the same
distance
from the displacement path of the rotating cylinder's raspbars 50. Also in
accordance
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with the present invention, the upper edges of each of the crossbars extends
above
the upper edges of the curved intermediate bars 72 as well as above the upper
edges of each of the curved end brackets 54. The fixed separation distance
between
the upper edge of each of the crossbars and the rotating cylinder's raspbars
50 as
they are rotationally displaced along the concave 24 can be seen in the
sectional
view of FIG. 5. This fixed, progressively, close spacing between the
rotationally
displaced raspbars 50 of the rotating cylinder 52 and the concave's crossbars
extends over the entire width of the concave 24 from its leading to its
trailing edge for
separating the grain bearing portion of the plant from its leafy residue.
The circular arc cross section of the concave 24 and the close, fixed,
progressive, spacing between the concave's crossbars and the rotationally
displaced
raspbars 50 allows the combine 10 to harvest at a faster rate and to reduce
damage
caused by friction and impact between the raspbars 50 and the crossbars.
While prior art concaves employ equally spaced crossbars, e.g.,
typically thirteen (13) crossbars spaced an equal distance apart. The
progressively
spaced concave 24 crossbars of the present invention provides improved
threshing
action and better grain separation. Entrance end -crossbar spacing in the
present
invention is on the order of 1 5/16" inch, progressing to 1 1/8" and then to
1" while a
spacing of on the order of 1-1/4 inch is typically used in the prior art.
Upper and lower mounting bolts 64 securely attach respective ends of
each of the curved end brackets 54 to an adjacent, inner wall of the combine
10 (not
shown in the figures for simplicity). A lower plate extends between the two
curved
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end brackets 54 and along the length of the concave 24. The lower plate is
positioned in contact with the first, or leading, crossbar. A trap is
positioned adjacent
to the forward edge of the concave 24 for removing foreign matter ingested by
the
combine 10 such as rocks, soil and trash. The close, fixed spacing between the
rotationally displaced raspbars 50 and the forward portion of the concave 24
allows
the raspbars 50 to force the grain bearing portion of the harvested crop
through the
spaces between adjacent crossbars and to maintain these spaces, or inter-
crossbar
gaps, unclogged.
Disposed adjacent to and in contact with the last, or uppermost,
crossbar is a filler plate 44. The filler plate 44 extends the length of the
concave 24
and is securely attached at respective ends thereof to the two curved end
brackets
54 by conventional means such as weldments. The filler plate 44 extends upward
from the last crossbar and is generally L-shaped. The filler plate 44 and the
lower
plate, as well as other components of the concave 24 and cylinder described
herein
are preferably comprised of high strength, corrosion resistant steel.
The orientation of the angled bars of the finger grate and their close
proximity to the last crossbar facilitates upward and rearward displacement of
the
plant residue by the rotating raspbars 50. This is in contrast to the
configuration and
positioning of the prior art finger bars shown in FIG. 3, which do not guide
the plant
residue to a location below and aft of the rotating beater 56. In the prior
art
arrangement of FIG. 3, plant residue is displaced upward by the rotating
raspbars 50
and into the rotating beater 56. Some of the plant residue is displaced by the
rotating
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raspbars 50 to a location forward of the rotating beater 56 which is then
unable to
rearwardly displace this plant residue, resulting in back feeding of the
residue onto
the rotating cylinder 52 and its displacement again between the cylinder and
concave
24. The rearward and upward slope of the angled bars of the finger grate of
the
5 present invention allows these bars to guide the plant refuse to a
location adjacent to
a lower, aft portion of the rotating beater 56 which facilitates further aft
displacement
of the plant residue by the beater and away from the cylinder-concave 24
threshing
combination.
There has thus been shown an improved cylinder and concave 24
10 arrangement for use in a combine 10 for separating the grain bearing and
leafy
portions of a plant. The progressively closer spacing of the cross bars 30
concave's
crop engaging members relative to the rotationally displaced cylinder's
raspbars 50
permits the full thrashing extent of the concave 24 to be used for grain
separation,
prevents impact damage of the grain by the moving raspbars 50, eliminates crop
15 residue back feeding onto the cylinder, and allows the cylinder to
rotate more slowly
with increased grain recovery and improved fuel efficiency.
While particular embodiments of the present invention have been
shown and described, it will be obvious to those skilled in the art that
changes and
modifications may be made without departing from the invention in its broader
20 aspects. Therefore, the aim in the appended claims is to cover all such
changes and
modifications as fall within the scope of the invention. The matter set forth
in the
CA 02599263 2014-05-29
21
foregoing description and accompanying drawings is offered by way of
illustration
only and not as a limitation
Referring to FIG.5, a preferred embodiment of the threshing or
separation mechanism 12 illustrating the crop entrance 48 point, the crop
pinch point
47 the crop exit 46 from a rear view. point. A corn cob 82 illustrates the
means that
various seeds and grains are positioned between the concave 24 and the
rotating
cylinder 52 as they travel through the combine's separation mechanism 12.
Concaves
can be adjustable at both the crop entrance 48 and crop exit 46 points as well
as at
the pinch point 47. Progressive spacing 88 of the bars 30 begins at the crop
entrance
48 point and diminishes in spacing of the bars 30 as the direction of the crop
exit 46
is obtained.
FIG. 6, each concave 24 includes opposite transversely extending side
frame members or ribs 34, which terminate along one end. Two intermediate
frame
members 84 also extend transversely along the cicumferential span of the
concave
24. A plurality of longitudinally extending frame members, configured as bars
30,
extend between and are connected to the opposite side frame members and
intersect
the intermediate frame members 84. The concave 24 inserts also include a
plurality
of longitudinally spaced arcuate rods 32 that extend between the ends of the
concave
24 insert through the plurality of bar members below a top edge thereof. The
spaces
or openings formed between the rods, bar members and frame members form
apertures through which the grain passes as the crop materials are threshed
between
the concave 24 and the adjacent, cooperating rotor 13. In various suitable
CA 02599263 2014-05-29
22
embodiments, the openings have a range of widths from about 1 1/2 inch to
about 1/4
inch and a length of from about 1 1/2 inch to about 3/4 inches, depending on
the type
of grain being threshed. The various concave 24 insert components, including
the
frames, rods, bearing plates and plates, are preferably made of a rigid
durable
material such as steel, although other materials would also work.
As best shown in FIG. 6, each concave 24 insert includes opposite
transversely extending side frame members or ribs 34, which terminate along
one
end in a downwardly extending hook portion. Two intermediate frame members 84
also extend transversely along the cicumferential span of the concave 24
insert. A
plurality of longitudinally extending frame members, configured as bar member,
extend between and are connected to the opposite side frame members and
intersect
the intermediate frame members 84. The lowermost frame member, which defines
an
end of the concave 24 insert, includes at least a pair of openings formed in a
lower
portion thereof. The concave 24 inserts also include a plurality of
longitudinally
spaced arcuate rods 32 that extend between the ends of the concave 24 insert
through the plurality of bar members below a top edge thereof. The spaces or
openings formed between the arcuate rods 32, bar members and frame members
form apertures through which the grain passes as the crop materials are
threshed
between the concave 24 insert and the adjacent, cooperating rotor 13. In
various
suitable embodiments, the openings have a range of widths from about 1/4 inch
to
about 1 1/2 inch and a length of from about 3/4 inch to about 11/2 inches,
depending
on the type of grain being threshed. The various concave 24 insert components,
CA 02599263 2014-05-29
23
including the frames, arcuate rods 32, bearing plates and plates, are
preferably made
of steel, although other materials would also work.
Referring to FIG. 7. A front inside and side view of a most preferred
embodiment of a concave 24 in accordance with the principles of the present
invention. The concave 24 includes a pair of curved end brackets 54 and a
plurality
of linear, elongated crossbars or bars 30 extending therebetween. Coupled to
and
extending through the plurality of cross bars 30 are a plurality of flush
mounted
arcuate rods 90. Each of the curved end brackets 54 and is shaped in the form
of a
circular arc over the full length thereof. Thus, the concave 24 is disposed in
closely
spaced, parallel relation to the rotating raspbars 50 of the cylinder. The
upper edges
of each of the crossbars are similarly disposed in closely spaced relation and
at the
same distance from the displacement path of the rotating cylinder's raspbars
50. Also
in accordance with the present invention, the upper edges of each of the
crossbars is
flush with the upper edges of each of the curved end brackets 54 as are the
arcuate
rods 32. The fixed separation distance between the upper edge of each of the
crossbars and the rotating cylinder's raspbars 50 as they are rotationally
displaced
along the concave 24 can be seen in the sectional view of FIG. 5. This fixed,
progressively, close spacing between the rotationally displaced raspbars 50 of
the
rotating cylinder 52 and the concave's crossbars extends over the entire width
of the
concave 24 from its leading to its trailing edge for separating the grain
bearing
portion of the plant from its leafy residue.
CA 02599263 2014-05-29
24
The circular arc cross section of the concave 24 and the close, fixed,
progressive, spacing between the concave's crossbars and the rotationally
displaced
raspbars 50 allows the combine 10 to harvest at a faster rate and to reduce
damage
caused by friction and impact between the raspbars 50 and the crossbars. This
occurs in part, from the ability of the concave 24 to provide various spacings
to better
fit the separation characteristics presented by the toughness or ease of seed
and
grain separation characteristics offered by the crop.
While prior art concaves employ equally spaced crossbars, e.g.,
typically thirteen (13) crossbars spaced an equal distance apart. The
progressively
spaced concave 24 crossbars of the present invention provides improved
threshing
action and better grain separation. Entrance end -crossbar spacing in the
present
invention is on the order of 1 5/16" inch, progressing to 1 1/8" and then to
1" while a
spacing of on the order of 1-1/4 inch is typically used in the prior art.
Upper concave hanger 92 brackets and lower mounting bolts 64
securely attach respective ends of each of the curved end brackets 54 to an
adjacent,
inner wall of the combine 10 (not shown in the figures for simplicity). A
lower plate
extends between the two curved end brackets 54 and along the length of the
concave
24. The lower plate is positioned in contact with the first, or leading,
crossbar.
The orientation of the angled bars of the finger grate and their close
proximity to the last crossbar facilitates upward and rearward displacement of
the
plant residue by the rotating raspbars 50. This is in contrast to the
configuration and
positioning of the prior art finger bars shown in FIG. 3, which do not guide
the plant
CA 02599263 2014-05-29
residue to a location below and aft of the rotating beater 56. In the prior
art
arrangement of FIG. 3, plant residue is displaced upward by the rotating
raspbars 50
and into the rotating beater 56. Some of the plant residue is displaced by the
rotating
raspbars 50 to a location forward of the rotating beater 56 which is then
unable to
5
rearwardly displace this plant residue, resulting in back feeding of the
residue onto
the rotating cylinder 52 and its displacement again between the cylinder and
concave 24 . The rearward and upward slope of the angled bars of the finger
grate of
the present invention allows these bars to guide the plant refuse to a
location
adjacent to a lower, aft portion of the rotating beater 56 which facilitates
further aft
10
displacement of the plant residue by the beater and away from the cylinder-
concave
24 threshing combination.
There has thus been shown an improved concave 24 arrangement for
use in a combine 10 for separating the grain bearing and leafy portions of a
plant.
The progressively closer spacing of the cross bars 30 concave's crop engaging
15
members relative to the rotationally displaced cylinder's raspbars 50 permits
the full
thrashing extent of the concave 24 to be used for grain separation, prevents
impact
damage of the grain by the moving raspbars 50, eliminates crop residue back
feeding
onto the cylinder, and allows the cylinder to rotate more slowly with
increased grain
recovery and improved fuel efficiency.
20 While
particular preferred embodiments of the present invention have
been shown and described, it will be obvious to those skilled in the art that
changes
and modifications may be made without departing from the invention in its
broader
CA 02599263 2014-05-29
26
aspects. Therefore, the aim in the appended claims is to cover all such
changes and
modifications as fall within the scope of the invention. The matter set forth
in the
foregoing description and accompanying drawings is offered by way of
illustration
only and not as a limitation.
Since other modifications and changes varied to fit particular operating
requirements and environments will be apparent to those skilled in the art,
the
invention is not considered limited to the example chosen for purposes of
disclosure,
and covers all changes and modifications which do not constitute departures
from the
scope of this invention.
Having thus described the invention, what is desired to be protected by
Letters Patent is presented in the subsequently appended claims.
