U.S. patent application number 13/614045 was filed with the patent office on 2014-03-13 for combine harvester sieve assembly with an integrated air cleaning system.
This patent application is currently assigned to CNH AMERICA LLC. The applicant listed for this patent is Herbert M. Farley, Jonathan Eugene Ricketts, Martin J. Roberge. Invention is credited to Herbert M. Farley, Jonathan Eugene Ricketts, Martin J. Roberge.
Application Number | 20140073380 13/614045 |
Document ID | / |
Family ID | 49230506 |
Filed Date | 2014-03-13 |
United States Patent
Application |
20140073380 |
Kind Code |
A1 |
Ricketts; Jonathan Eugene ;
et al. |
March 13, 2014 |
Combine Harvester Sieve Assembly with an Integrated Air Cleaning
System
Abstract
A combine harvester that employs a sieve assembly having a frame
structure with movement that facilitates pressurizing an air supply
connected thereto. Various aspects of the subject disclosure
provide for sieve elements having internal air passages that are
supported in the frame structure. A plurality of pressurized air
ports are disposed along the frame structure or sieve elements and
are oriented at an angle so as to direct pressurized air upwardly
through the sieve elements. The pressurized air supply is in
communication with the air ports.
Inventors: |
Ricketts; Jonathan Eugene;
(Coal Valley, IL) ; Farley; Herbert M.;
(Elizabethtown, PA) ; Roberge; Martin J.;
(Saskatoon, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ricketts; Jonathan Eugene
Farley; Herbert M.
Roberge; Martin J. |
Coal Valley
Elizabethtown
Saskatoon |
IL
PA |
US
US
CA |
|
|
Assignee: |
CNH AMERICA LLC
New Holland
PA
|
Family ID: |
49230506 |
Appl. No.: |
13/614045 |
Filed: |
September 13, 2012 |
Current U.S.
Class: |
460/101 |
Current CPC
Class: |
A01F 12/444
20130101 |
Class at
Publication: |
460/101 |
International
Class: |
A01F 12/32 20060101
A01F012/32; A01F 12/44 20060101 A01F012/44 |
Claims
1. A sieve assembly for a combine harvester, comprising: a frame
structure with movement driven by a reciprocating drive; sieve
elements supported in said frame structure; the sieve elements with
air passages that are internal thereto; a plurality of pressurized
air ports disposed along said frame structure and as part of the
sieve elements oriented at an angle so as to direct pressurized air
upwardly through said sieve elements into a space that has no
substantial increase in pressure over a surrounding thereof; and a
pressurized air supply that is pressured by the reciprocating
drive, wherein the pressurized air supply is in communication with
said air ports.
2. The sieve assembly as in claim 1, wherein said frame structure
defines internal air conduits in communication with said air ports,
said internal air conduits in communication with said pressurized
air supply.
3. The sieve assembly as in claim 2, wherein said internal air
conduits are defined in longitudinal and transverse components of
said frame structure so as to define an internal air conduit
grid.
4. The sieve assembly as in claim 2, wherein said air ports
comprise holes defined in said frame structure at an angular
orientation to direct pressurized air through said sieve
elements.
5. The sieve assembly as in claim 2, wherein said air ports
comprise nozzles connected to said frame structure, said nozzles in
communication with said internal air conduits.
6. The sieve assembly as in claim 1, comprising a plurality of
external air conduits attached to said frame structure, said air
ports defined in said external air conduits.
7. The sieve assembly as in claim 6, wherein said external air
conduits are attached to components of said frame structure so as
to define an external air conduit grid supported on said frame
structure.
8. The sieve assembly as in claim 6, wherein said air ports
comprise nozzles connected to said external air conduits.
9. The sieve assembly as in claim 6, wherein said air ports
comprise holes defined in said external air conduits at an angular
orientation to direct pressurized air through said sieve
elements.
10. The sieve assembly as in claim 1, wherein said pressurized air
supply comprises a connection to an air compressor source of the
combine harvester.
11. The sieve assembly as in claim 1, wherein said pressurized air
supply comprises an accumulator that discharges air to said air
ports in a continuous or pulsed manner in response to a control
signal from a controller.
12. The sieve assembly as in claim 1, further comprising a
reciprocating drive connected to said frame structure, said
pressurized air supply comprising a compressor mechanism driven by
said reciprocating drive.
13. The sieve assembly as in claim 12, wherein said compressor
mechanism is passively driven by return strokes of said
reciprocating drive.
14. The sieve assembly as in claim 12, wherein said compressor
mechanism is actively driven by power strokes of said reciprocating
drive.
15. The sieve assembly as in claim 12, wherein said compressor
mechanism comprises an air piston in direct communication with said
air ports such that pulsating air jets are produced from said air
ports at a frequency corresponding to a drive frequency of said
reciprocating drive.
16. The sieve assembly as in claim 12, wherein said compressor
mechanism is in communication with an accumulator, wherein
discharge of pressurized air from said accumulator is controlled by
a controller so as to produced pulsed or continuous air jets from
said air ports.
17. A sieve assembly for a combine harvester, comprising: a frame
structure, said frame structure defining internal air conduits, the
frame structure with a return stroke that compresses air into a
pressurized air supply; sieve elements supported in said frame
structure, said sieve elements having internal air passages in
communication with said internal air conduits of said frame
structure; a plurality of pressurized air ports disposed along at
least a plurality of said sieve elements and internal thereto, the
oriented at an angle so as to direct pressurized air from internal
air passages into a space that has no substantial increase in
pressure over a surrounding thereof, to effect a cleaning of said
sieve elements; and the pressurized air supply being pressurized by
the return stroke, wherein the pressurized air supply is in
communication with said air ports via said frame structure and said
sieve elements.
18. The sieve assembly as in claim 17, wherein said sieve elements
have a generally hollow interior in communication with said
internal air conduits of said frame structure.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to agricultural
combine harvesters, and more particularly to a sieve assembly in a
combine cleaning unit.
BACKGROUND OF THE INVENTION
[0002] With conventional combine harvesters, the crops that are
severed by the header are conveyed to a threshing and separating
assembly where a rotor is rotated within a generally cylindrical
chamber to thresh the crops. Grain, seed, or the like, is loosened
and separated from the other crop material and falls onto a grain
pan of a cleaning assembly, which typically includes a pre-cleaning
sieve disposed above a second grain pan. The grain is then conveyed
to a pair of stacked sieves disposed one above the other. The grain
pans and sieves are generally oscillated in a back-and-forth motion
for transporting and spreading the grain across the sieves, which
separate or sift the grain from tailings and "material other than
grain" (MOG). The cleaned grain passes by gravity through the
apertures in the sieves to underlying clean grain collecting
troughs where the grain is directed to a clean grain auger.
[0003] During vibration of the sieves, a cleaning fan is typically
used to blow air upwardly and rearwardly through the sieves to
carry lighter elements of the MOG, or chaff, away. The heavier
elements and tailings that are too large to fall through the sieves
and too heavy to be blown away are moved by the vibrations of the
sieves generally rearwardly along the top surface of the sieves,
and towards and over the edges of the sieves to fall onto a
tailings pan, which is typically a plurality of tailings collecting
troughs that convey the tailings to a tailings auger trough. This
trough delivers the tailings to a return conveyor that carries the
tailings back to the cleaning and separating system for
reprocessing.
[0004] Often times, the air from the cleaning fan is inadequate to
break up clusters of grain and MOG that accumulate and roll on the
sieves. This material will eventually accumulate and overload the
cleaning system, whereby the sieves lose their ability to separate
the MOG from the grain. This situation often requires a shutdown
and manual cleaning of the system.
[0005] An improved separating and cleaning system that decreases
overloading of top and bottom sieves would be a welcome advancement
in the industry.
BRIEF DESCRIPTION OF THE INVENTION
[0006] Aspects and advantages of the invention will be set forth in
part in the following description, or may be obvious from the
description, or may be learned through practice of the
invention.
[0007] In accordance with aspects of the invention, a sieve
assembly is provided for a combine harvester. The sieve assembly
includes any manner of frame structure on which a plurality of
sieve elements are supported. The sieve elements may be, for
example, fixed or adjustable louvers, as is known in the art. A
plurality of air ports are operably disposed along the frame
structure and are oriented at an angle so as to direct pressurized
air upwardly through the sieve elements. The air ports are in flow
communication with a pressurized air supply and direct a continuous
or pulsed air jet through the sieve elements to aid in agitating
and separating the MOG from the grain.
[0008] In a conventional combine harvester utilizing an upper and
lower sieve element, either or both of the sieve elements may be
configured with the pressurized air ports, as set forth herein.
[0009] In a particular embodiment, the frame structure may include
any number and configuration of generally hollow members that
define internal air conduits in communication with the air ports.
The frame structure is connected to a pressurized air supply such
that pressurized air flows through the internal conduits and
discharges from the air ports. In a certain embodiment, the
internal conduits may be defined in any pattern of longitudinal and
transverse components of the frame structure so as to define an
internal air conduit grid. The internal conduits may be defined in
only select members of the frame structure, such as the transverse
members that extend generally perpendicular to the direction of
grain flow along the sieve element.
[0010] The air ports may be variously configured. For example, the
air ports may simply be holes in the frame structure (or other type
of air conduits) that are defined at an angular orientation to
direct pressurized air upwards and through the sieve elements. In
an alternate embodiment, the air ports may be defined by adjustable
or fixed nozzles that are attached to the frame structure.
[0011] In a different embodiment, a plurality of external air
conduits may be attached to the frame structure, with the air ports
defined as holes or nozzles in the external air conduits. For
example, a tubular grid conduit may be separately formed and
attached to the frame structure and pressurized air supply. This
embodiment provides any desired number and location of air ports
relative to the surface area of the sieve regardless of the
existing frame structure.
[0012] In still another embodiment of a sieve assembly in
accordance with aspects of the invention, the sieve elements have
internal air passages that are in communication with the internal
air conduits of the frame structure. Air ports are defined at
suitable locations in at least a plurality of the sieve elements to
direct the pressurized air from the individual sieve elements at an
angle to effect cleaning of the sieve elements. In a particular
configuration, the sieve elements may have a generally hollow
interior that is in communication with the internal air conduits of
the frame structure. Alternately, external air passage structure
may be affixed to the sieve elements, for example along the edge of
the sieve elements.
[0013] Pressurized air may be provided from various sources in the
combine harvester. In one embodiment, the combine includes an
onboard air compressor that may be a dedicated source for the sieve
assembly, or may serve any number of other engine or systems
functions. This compressor may charge an accumulator (e.g., air
tank), wherein discharge from the accumulator is controlled by a
controller so as to direct pulsed or continuous air jets from the
air ports. For example, the controller may cycle a solenoid valve
that is operably disposed between the accumulator and air ports for
this purpose.
[0014] In a particular embodiment, the frame structure is driven in
a traversing motion by any suitable reciprocating drive. This
motion causes the grain/MOG to be conveyed along the sieve. The
reciprocating drive may also be connected to a compressor
mechanism, such as an air piston, to generate the pressurized air.
The piston may be actively driven by the reciprocating drive in a
power stroke that also drives the frame structure, which may
require a larger or more powerful drive mechanism. With
conventional drive systems, the frame structure typically returns
to a home position under its own weight and inertia after the power
stroke, which in turn causes the crank arm of the drive to return
to a corresponding home position. In a unique embodiment, this
passive return stroke of the drive mechanism is used as an energy
source to power a compressor mechanism. For example, a crank
attached to the reciprocating drive may be connected to an air
piston that generates pressurized air on the return stroke of the
drive. This piston may be connected directly in line with the
conduits and air ports such pulsating air jets are produced from
the air ports at a frequency corresponding to a drive frequency of
the reciprocating drive. Alternately, the piston may charge an
accumulator, as discussed above.
[0015] These and other features, aspects and advantages of the
present invention will become better understood with reference to
the following description and appended claims. The accompanying
drawings, which are incorporated in and constitute a part of this
specification, illustrate embodiments of the invention and,
together with the description, serve to explain the principles of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] A full and enabling disclosure of the present invention,
including the best mode thereof, directed to one of ordinary skill
in the art, is set forth in the specification, which makes
reference to the appended figures, in which:
[0017] FIG. 1 is a side view of a conventional combine
harvester;
[0018] FIG. 2 is a side and partial cut-away view of a combine
grain cleaning assembly incorporating aspects of the present
invention;
[0019] FIG. 3 is a perspective view of a sieve assembly
incorporating an embodiment of an air cleaning system;
[0020] FIG. 4 is a bottom and partial cut-away view of a sieve
assembly incorporating an embodiment of an air cleaning system;
[0021] FIG. 5 is an end cross-sectional view of an embodiment of a
sieve assembly incorporating an air cleaning system;
[0022] FIG. 6 is an end cross-sectional view of an alternate
embodiment of a sieve assembly incorporating an air cleaning
system;
[0023] FIG. 7 is a component view of an embodiment of a sieve
assembly incorporating an air cleaning system;
[0024] FIG. 8 is a component view of an alternate embodiment of a
sieve assembly incorporating an air cleaning system;
[0025] FIG. 9 is a component view of still another embodiment of a
sieve assembly incorporating an air cleaning system;
[0026] FIG. 10 is a partial top view of an alternate embodiment of
a sieve assembly incorporating an embodiment of an air cleaning
system;
[0027] FIG. 11 is a component view of another embodiment of a sieve
assembly incorporating an air cleaning system; and
[0028] FIGS. 12A through 12C are graphs of exemplary air blast
profiles for a sieve air cleaning system.
DETAILED DESCRIPTION OF THE INVENTION
[0029] Reference now will be made in detail to embodiments of the
invention, one or more examples of which are illustrated in the
drawings. Each example is provided by way of explanation of the
invention, not limitation of the invention. In fact, it will be
apparent to those skilled in the art that various modifications and
variations can be made in the present invention without departing
from the scope or spirit of the invention. For instance, features
illustrated or described as part of one embodiment can be used with
another embodiment to yield a still further embodiment. Thus, it is
intended that the present invention covers such modifications and
variations as come within the scope of the appended claims and
their equivalents.
[0030] Referring now to the drawings, wherein like numbers refer to
generally like items or features, FIG. 1 depicts a conventional
combine harvester 10 having a feeder house 14 on a front end
thereof, to which is connectable a header (not shown), operable to
sever a swath of crops from a field as the combine 10 moves forward
and to convey the severed crops to feeder house 14. Feeder house 14
includes an internal conveying system (not shown), for conveying
the crops upwardly and rearwardly into the body 12 of the combine
10 and into an inlet of a separating or threshing system 16.
Threshing system 16 generally includes a rotor at least partially
enclosed in a concave defining an arcuate space therebetween, and
in which space the crop material is processed for separating grain
and material other than grain (MOG) from straw, with the straw
being ejected rearwardly from the threshing system 16 through the
rear end of the combine 10 for deposit on the field, as is
well-known.
[0031] As threshing system 16 operates, crop material will fall
and/or be conveyed therefrom, as denoted generally by arrows "A" in
FIG. 1, onto an upper sieve 18 of a cleaning system 20 located
below threshing system 16 within the body of combine 10. Such
cleaning system 20 also includes a lower sieve 22 positioned below
upper sieve 18 in a stacked relationship therewith. The sieves 18
and 22 are configured to be reciprocally moved or vibrated relative
to one another to effect a sifting of material falling onto the
upper sieve 18, as indicated by arrow "B" in FIG. 1.
[0032] As the crop material from the threshing system 16 falls onto
upper sieve 18, air from a fan 26 is blown upwardly and rearwardly
through sieves 18 and 22, as indicted by arrow "C" in FIG. 1. In
conventional combines, this combination of air flow and the
vibratory movement of the sieves 18 and 22 is meant to cause the
lighter elements of the MOG (also referred to as chaff) to be blown
upwardly and rearwardly away from sieves 18 and 22. Such chaff is
typically blown into an optional chaff spreader (not shown),
operable for distributing the chaff over a desired swath of the
field from which the crop is cut, or directed into an optional
chopper (also not shown), operable for mixing the chaff with straw
for chopping and distributing such mix, or simply directed
downwardly onto the field through a rear opening of the combine,
all of which operations are well-known in the art.
[0033] The upper sieve 18 includes openings therethrough that are
sized to allow separated grain as well as some smaller elements of
MOG, sometimes referred to as tailings, to pass therethrough and to
fall onto lower sieve 22 of the cleaning system 20, thus sifting
the separated grain and tailings from larger elements of MOG. The
larger elements of MOG that are unable to pass through upper sieve
18 are moved to the rear peripheral edge portion of the sieve by
the vibratory movements of such sieve and fall either directly onto
the underlying field or onto or into other apparatus for further
processing, including chopping and/or spreading. Such further
processing of the larger elements of MOG may be accomplished in
various well-known manners.
[0034] The lower sieve 22 has smaller openings than upper sieve 18,
such that the sieves 18 and 22 will act as a progressive sifting or
cleaning mechanism for separating and cleaning grain from the
tailings that were also able to pass through sieve 18. To
facilitate such sifting action and the flow of grain through the
stacked sieves 18 and 22, the sieves are vibrated or reciprocally
moved, typically in a fore and aft direction, as denoted by arrow
B. The grain that falls through lower sieve 22 into clean grain and
tailings systems 12 of the combine 10 is considered to be clean
grain that is desired to be collected and ultimately conveyed to a
grain tank 24. The tailings that are allowed to pass through the
upper sieve 18 often still contain some un-separated grain, and
retention of such tailings for further processing to effect
separation of the grain is generally desired. The tailings that are
unable to pass through the smaller openings on lower sieve 22 are
caused to move towards a rear peripheral edge portion 28 of sieve
22, and to fall by the vibratory movement of lower sieve 22 into
clean grain and tailings system 12 for further processing.
[0035] Referring to FIG. 2, certain elements of the cleaning system
20 are depicted in greater detail, as well as further details of
the clean grain and tailings conveying system 12. In this regard,
FIG. 2 illustrates the manner in which sieves 18 and 22 may be
suspended from a structural frame 30 of combine 10 by pivoting
support arms 32 and 34, respectively, for reciprocal fore and aft
movement denoted by arrow B. Such movement may be readily effected
by various suitable and well known reciprocating drive mechanisms
(not shown) that operate in well-known manners. Clean grain and
tailings conveying system 12 is depicted as being fixedly connected
or mounted below lower sieve 22 of cleaning system 20 to structural
frame 30 by brackets 36 and 38, so as to be immovable relative to
structural frame 30.
[0036] As indicated in FIG. 2 and explained in greater detail
below, in accordance with aspects of the present invention, the
sieves 18 and 22 may be configured with an assembly 100 for
directing pressurized jets air via ports 110 in a pulsating or
continuous manner through the sieve elements 18, 22 to enhance the
separating action.
[0037] The clean grain and tailings conveying system 12 of FIGS. 1
and 2, generally includes a pan 40 that is fixedly mounted to
structural frame 30 by brackets 36 and 38 so as to be located
directly beneath lower sieve 22. This pan 40 may include an array
of elongated, longitudinally extending collecting troughs 42
positioned side-by-side across the width of pan 40. Such collecting
troughs 42 generally extend in the fore and aft direction, between
a forward edge 48 and a rear edge 50 of trough 42. Each collecting
trough 42 has a clean grain receiving portion 52 located beneath
those regions of lower sieve 22 through which clean grain is
expected to fall, and a tailings receiving portion 54 positioned
beneath peripheral edge portion 28 of lower sieve 22. A deflector
shield 56 is preferably disposed beneath the rear end portion of
lower sieve 22 to deflect clean grain onto clean grain receiving
portion 52 of pan 40, as opposed to tailings receiving portion 54
located below the rear end.
[0038] A clean grain auger trough 58 is disposed generally
cross-wise to and in communication with the clean grain collecting
troughs 42 of clean grain receiving portion 52 such that clean
grain can be conveyed through the clean grain collecting troughs to
the clean grain auger trough. A tailings auger trough 60 is
disposed generally cross-wise to and in communication with the
tailings collector troughs 42 of tailings receiving portion 54.
[0039] An elongated, helical auger 62 is supported in each
collecting trough 42, with each auger 62 including a first helical
auger flight 64 extending in a first predetermined rotational
direction and a second helical auger flight 66 and third auger
flight 68 extending in a second rotational direction opposite the
first rotational direction. Each auger 62 is connected to a drive
mechanism, which may include a bevel gear 70 on the rear end of
auger 62 that meshes with a drive gear (not shown) rotated by any
suitable drive, such as a belt, chain or shaft, in connection with
a power plant of combine 10 (not shown).
[0040] When augers 62 are rotated in a predetermined rotational
direction, flights 64, 66, and 68 will convey clean grain and
tailings separately and simultaneously along collecting troughs 42,
with clean grain from the clean grain collecting troughs being
moved into clean grain auger trough 58 and tailings from the
tailings collector troughs being moved into tailings auger trough
60. Clean grain auger trough 58 preferably has a helical auger 76
associated therewith and tailings auger trough 60 preferably has a
similar auger 78 associated therewith, which augers are rotatable
in the conventional manner using suitable drives (not shown) for
conveying the clean grain and tailings, respectively, to a clean
grain elevator (not shown) and a tailings return system (also not
shown), in well-known manners.
[0041] Referring again to FIG. 2, a sieve assembly 100
incorporating aspects of the present invention is depicted. Either
or both of the upper sieve 18 and lower sieve 22 are configured
with a plurality of air ports 110 disposed along the respective
frame structure 102 (FIG. 3) of the sieve elements. The air ports
110 are distributed in a pattern and are oriented at an angle so as
to direct pressurized air upwardly through the sieve elements, as
graphically depicted in FIG. 2. The air ports 110 are in
communication with a source of pressurized air, as discussed in
greater detail below. The air ports 110 are preferably provided in
a number and arranged in a pattern so as to provide generally
uniform coverage over the surface area of the respective sieves 18,
22. The pressurized air discharged from the ports 110 may be
continuous in one embodiment, or may be pulsed in another
embodiment. The air may be in addition to the air provided by the
fan 26 (FIG. 1) or, in certain embodiments, the assembly 100 may
replace the fan 26.
[0042] The air jets from the ports 110 serve to break up the
clusters of grain and MOG that may accumulate and roll on the
sieve, as discussed above.
[0043] Referring to FIGS. 3 and 4, embodiments of a sieve assembly
100 are depicted. The sieve assembly 100 includes a frame structure
102 typically comprised of longitudinal members 106 and transverse
members 104 that define a grid-type configuration. Sieve elements
108 are supported by the frame structure 102. The invention is not
limited by any particular type of sieve element 108 or frame
structure 102. Typical sieve elements 102 may be louver elements,
as is generally well-known in the art and need not be described in
detail herein.
[0044] Still referring to FIGS. 3 and 4, the frame structure 112
may be defined by internal air conduits 114 within the frame
structure elements 104, 106. For example, the structural elements
104, 106 may be generally hollow tubular elements that are in
communication with a pressurized air source via a connection 105.
FIG. 4 is a bottom view of this particular embodiment and
illustrates that the frame member elements 104, 106 define an
internal conduit grid 116 below the sieve elements 108. Air ports
(not visible in FIG. 4) are in communication with the internal air
conduits 114 for directing the pressurized air from the internal
air conduit grid 116 at the desired angular orientation relative to
the sieve elements 108.
[0045] For example, referring to FIG. 5, an end cross-sectional
view of a particular embodiment of a sieve assembly 100 is depicted
wherein the air ports 110 that direct the pressurized air from the
internal air conduits 114 are defined simply as holes 118 in the
structural frame members 106. The holes 118 are defined at a
desired angular orientation so as to direct the pressurized air
upwards and through the respective sieve elements 108, as generally
depicted by the flow arrows in FIG. 5.
[0046] In the embodiment of FIG. 6, the air ports 110 are defined
by nozzles 120 that are mounted onto the structural frame members
106. These nozzles 120 may be fixed in position or adjustable and
serve to direct the pressurized air upwards through the sieve
elements 108.
[0047] FIG. 7 depicts an embodiment wherein a grid configuration
124 of external conduit members 122 is provided for attachment to
the structural members 104, 106 of the frame structure 102 by any
suitable means. The external conduits 122 may be, for example,
tubular members that are also defined into a grid 124 that may
essentially compliment or match the grid configuration of the frame
structure 102 so as to be securely mounted to the underside of the
frame structure elements 104, 106. In an alternate embodiment, the
external conduits 122 may be spaced between the structural members
106, 104 of the frame structure 102. The external conduits are
provided with a plurality of air ports 110 in a number and pattern
so as to define a desired degree of coverage below the surface area
of the sieve elements 108. It should be appreciated that the
invention is not limited to any particular number of air ports 110
or pattern. In the embodiment depicted in FIG. 7, the air ports 110
are nozzles 120, which may be fixed or adjustable. The air ports
110 may, in an alternate embodiment, be defined simply as holes 118
(FIG. 5) defined in the external conduits 122.
[0048] The sieve assembly 100 may be provided with a source of
pressurized air via any suitable existing system on the combine 10
(FIG. 1). For example, referring to FIG. 8, the combine 10 may
include an air compressor 126 that serves various engine and/or
other operational functions. This compressor 126 may be used to
charge an accumulator or tank 128 that supplies pressurized air to
the frame structure 102 (or external conduit grid 124). Discharge
from the air tank 128 may be controlled by a controllable valve
130, such as a solenoid valve, that is cycled by a system
controller 132 to provide either continuous or pulsed air through
the sieve assembly 100, as discussed above.
[0049] It should be appreciated that, in an alternate embodiment, a
dedicated air compressor or other pressurized air source may be
provided within the combine 10 for supplying the sieve assembly
100.
[0050] FIG. 9 depicts an embodiment of a sieve assembly 100 in
accordance with aspects of the invention wherein the pressurized
air source 112 is functionally provided by the reciprocating drive
134 used to drive the sieve frame structure 102 in its vibratory
to-and-fro motion, as discussed above. Any type of suitable
reciprocating drive 134 may be utilized, as is well known by those
skilled in the art. In a typical configuration, the reciprocating
drive 134 utilizes a cam to drive a crank arm 136 connected to the
frame structure 102. With these type of systems, the frame
structure 102 typically returns to a home position under its own
weight and inertia after the power stroke of the crank arm 136,
which in turn causes the crank arm 136 or cam to return to a
corresponding home position. In certain known systems, this return
stroke must be buffered or dampened. In the embodiment depicted in
FIG. 9, the energy of the return stroke of the drive mechanism 134
is harnessed to drive a compressor mechanism 140, such as an air
piston. As schematically indicated in FIG. 9, the drive mechanism
134 is mechanically connected to the compressor mechanism 140
through any manner of suitable linkage in order to drive the
mechanism 140. For example, in the embodiment depicted in FIG. 9, a
second crank arm 138 may be operably connected to the drive
mechanism 134 so that on the return stroke of the drive mechanism,
the crank arm drives piston within an air piston embodiment of the
compressor mechanism 140. The output of this mechanism 140 may be
used to charge an accumulator or tank 128, which then supplies the
pressurized air via a control valve 130 to the frame structure 102
under the control of a controller 132.
[0051] It should further be appreciated that an embodiment similar
to that depicted in FIG. 9 may be provided within the drive
mechanism 134 also charges the air tank 128 via a compressor
mechanism 140 on the positive drive stroke of the drive mechanism
134, instead of on the passive return stroke as discussed
above.
[0052] FIG. 10 depicts an embodiment of a sieve assembly 100
wherein the air ports 110 are defined on the individual sieve
elements 108 instead of or in combination with ports defined on the
frame structure 102. For example, the frame structure 102 may
define internal air conduits 114 in the transverse members 104 and
longitudinal members 106 that are supplied with pressurized air via
any suitable air supply 112 (including those discussed above). The
individual sieve elements 108 include internal air passages 115
that are in flow communication with the internal air conduits 114
such that pressurized air is conducted from the frame members 102
to the sieve elements 108. For example, the sieve elements 108 may
be defined by shell members that define a generally hollow interior
volume that is in flow communication with the internal conduits 114
such that pressurized air is introduced directly into the
individual louvers of the sieve elements 108. In an alternate
embodiment, any manner of external or internal conduit members,
such as tubing or piping, may be configured within or external to
the sieve elements, with such conduit members being in flow
communication with the internal conduits 114 of the frame members
102.
[0053] Still referring to FIG. 10, it should be appreciated that
any pattern of ports 110 may be defined along any one or
combination of the sieve elements 108. It is not necessary that
every louver of the sieve elements have a port 110. The ports 110
are supplied in a number and pattern to provide an effective
cleaning of the sieve elements 108.
[0054] FIG. 11 depicts an embodiment of a sieve assembly 100
similar to the embodiment of FIG. 8 discussed above wherein an air
compressor 126 that serves various engine and/or other operational
functions is used to charge an accumulator or tank 128 that
supplies pressurized air to the frame structure 102 (or external
conduit grid 124) via connections 105. Discharge from the air tank
128 may be controlled by multiple controllable valves 130, such as
solenoid valves, that are cycled by a system controller 132 to
provide either continuous or pulsed air through the sieve assembly
100. The use of multiple valves 130 allows for different control
parameters for different parts or sections of the sieve assembly
100. For example a front blast pattern may be generated that is
different from a rear blast pattern, and so forth. It should be
appreciated that various configurations of valves 130 and different
control patterns are within the scope and spirit of the
invention.
[0055] FIGS. 12A through 12C depict various air blast frequency and
period patterns that may be utilized in any one of the sieve
assemblies 100 in accordance with aspects of the invention. The
nozzles may blow air jets at any designed frequency or period
(e.g., by appropriate control of valves 130) depending on any
number of factors, such as type of crop being harvested, and the
like. FIG. 12A depicts a relatively long air blast period relative
to sieve motion as compared, for example, to FIG. 12B. FIG. 12C
depicts a random air blast period relative to sieve motion.
[0056] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they include structural elements that do not
differ from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
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