Patent Description:
Self-propelled combine harvesters are used by farmers to harvest a wide range of crops. Typically, a combine harvester cuts crop material, threshes grain therefrom, separates the threshed grain from the straw, and cleans the grain before storage in an onboard grain tank. Straw and crop residue is ejected from the rear of the combine harvester in the field.

Combine harvesters may have one or more threshing cylinders that rotate on axes parallel to a direction of travel of the combine harvesters and thresh the cut crop material. Grain and chaff separated in this process falls due to gravity through a grate onto an underlying thresher pan, which is driven in an oscillating manner to convey the grain and chaff rearward to a rear edge, where the grain and chaff falls into a cleaning unit. The straw by-product is ejected from the rear of the combine.

The cleaning unit of most combines operates according to a well-established process in which grain and chaff (also referred to in the art as material other than grain (MOG)) cascading down from the thresher and separator pans is subjected to an airstream created by one or more fans. A chaffer has a frame that supports a series of louvers, which are positioned to allow grain to fall downward through the chaffer while allowing a flow of cleaning air to pass upward and rearward through the chaffer. The cleaning air flow tends to force MOG rearward and restricts MOG from falling through the chaffer. The heavier grain falls through the chaffer and optionally through another cleaning sieve below before being conveyed to the grain tank.

The speed of the airflow through the chaffer may be selected to balance various operational parameters for agronomic benefit, such as percentage of chaff removed from the crop material, percentage of grain lost from the rear of the machine, mass throughput, and fuel usage.

Cleaning units in combine harvesters are described in more detail in, for example, <CIT>; <CIT>; and <CIT>. <CIT> discloses a cleaning system for a combine harvester, the cleaning system comprising a chaffer with a perforated base and a plurality of longitudinal lateral sidewalls.

The invention provides a cleaning system according to claim <NUM>. Preferred embodiments are provided in the dependent claims.

While the specification concludes with claims particularly pointing out and distinctly claiming what are regarded as embodiments of the present disclosure, various features and advantages of the disclosure may be more readily ascertained from the following description of example embodiments when read in conjunction with the accompanying drawings, in which:.

The illustrations presented herein are not actual views of any combine harvester or portion thereof, but are merely idealized representations to describe example embodiments of the present disclosure. Additionally, elements common between figures may retain the same numerical designation.

The following description provides specific details of embodiments.

From reading the following description it should be understood that the terms "longitudinal" and "transverse" are made in relation to the combine harvester's normal direction of travel. In other words, the term "longitudinal" equates to the fore-and-aft direction, whereas the term "transverse" equates to the crosswise direction, or left and right. Furthermore, the terms "axial" and "radial" are made in relation to a rotating body such as a shaft, wherein axial relates to a direction along the rotation axis and radial equates to a direction perpendicular to the rotation axis.

With reference to <FIG>, a self-propelled combine harvester <NUM> is configured to carry a harvesting header that cuts and gathers a strip of crop as the combine harvester <NUM> is driven across a crop field in a forward direction F. A feederhouse <NUM> conveys the cut crop material from the harvesting header into a threshing system <NUM> in the combine harvester <NUM>, in which the crop material is threshed and separated. The threshing system <NUM> may include, for example, an axial flow processing rotor <NUM> as described in <CIT>; a transverse flow rotor as described in <CIT>; a hybrid system; or any other selected design.

The axial flow rotor <NUM> may generally move crop materials axially and helically rearward, threshing and separating grain from MOG. Concave assemblies <NUM> and separator grate assemblies <NUM> enable the grain to escape laterally and/or downward into a cleaning system <NUM> below. Bulkier stalk and leaf materials are retained by the concave assemblies <NUM> and the grate assemblies <NUM> and are impelled out the rear of the threshing system <NUM> and ultimately out the rear of the combine harvester <NUM>.

The cleaning system <NUM> includes a blower <NUM> that can provide a stream of air throughout the cleaning system <NUM>, which is directed out the rear of the combine harvester <NUM> to carry lighter chaff particles away from the grain as the grain migrates downward toward the bottom of the cleaning system <NUM> to a grain auger <NUM>. The auger <NUM> delivers the clean grain to an elevator that carries the grain to a storage bin <NUM> on top of the machine, from which it is ultimately unloaded via an extendible unloading spout <NUM> (shown in a stowed position). A return auger <NUM> at the bottom of the cleaning system <NUM> may be used to recirculate partially threshed crop material into the front of the threshing system <NUM> for an additional pass through the threshing system <NUM>.

The combine harvester <NUM> also typically includes an operator cab <NUM>, an engine, and wheels <NUM> and/or tracks. In some embodiments, the combine harvester <NUM> may include a controller <NUM> (represented in <FIG> simply as a rectangular box), typically located in the operator cab <NUM>, which the operator may use to control the combine harvester <NUM>.

The cleaning system <NUM> includes a series of pans or grates configured to separate grain from chaff. Crop material falls from the threshing system <NUM> onto a return pan <NUM> or a rear pan <NUM>, depending on the position in the threshing system <NUM> from which the crop material falls. The return pan <NUM> may deliver the crop material to a forward end of a stratification pan <NUM> located below the return pan <NUM>.

The stratification pan <NUM> conveys crop material rearward toward a chaffer <NUM> and a sieve <NUM>. The return pan <NUM>, rear pan <NUM>, stratification pan <NUM>, chaffer <NUM>, and/or sieve <NUM> may each be coupled to one or more motor(s) configured to shake the pans in an oscillating manner to help separate the crop material. The drive mechanism is conventional and is not described in detail herein. Less-dense material tends to move toward the top of the crop material, and more-dense material tends to move toward the bottom of the crop material. Air from the blower <NUM> blows rearward and upward through the chaffer <NUM> and sieve <NUM> and helps the chaffer <NUM> and sieve <NUM> separate grain from MOG. Thus, grain tends to fall through the chaffer <NUM> and sieve <NUM>, and MOG tends to be blown out the rear of the combine harvester <NUM>. The chaffer <NUM> and sieve <NUM> may operate as described in, for example, <CIT>; and <CIT>. The chaffer <NUM> and sieve <NUM> may also be referred to in the art as an upper sieve and lower sieve, respectively, because they may be of generally the same construction.

The cleaning system <NUM> is shown in <FIG>, and illustrates more detail of the chaffer <NUM> and sieve <NUM>. The chaffer <NUM> is shown in further detail in perspective view in <FIG>. The chaffer <NUM> has a perforated base <NUM>, which typically includes louvers <NUM> spaced along a length of a frame <NUM> of the chaffer <NUM>. Adjacent louvers <NUM> define openings through which air may flow upward and grain may fall downward.

The chaffer <NUM> has longitudinal lateral walls <NUM>, <NUM>, which may include left and right side walls <NUM> and one or more center walls <NUM> separating the chaffer <NUM> into multiple distinct sections (two sections are shown in <FIG>). The chaffer <NUM> may typically be divided into separate sections to limit the amount of material that can accumulate along the left or right side walls <NUM> when the combine harvester <NUM> is operating on a side hill (i.e., when the right side of the combine harvester <NUM> is higher or lower than the left side). That is, by separating the chaffer <NUM> into two sections, half of the crop material will be in each section.

To further limit accumulation of crop material along the lateral walls, the chaffer <NUM> may include a plurality of airbags <NUM> disposed adjacent to the walls <NUM>, <NUM>. <FIG> depicts just one airbag <NUM>, but another airbag <NUM> may be along the opposite side of the center wall <NUM>, and airbags <NUM> may be along each of the left and right side walls <NUM>. That is, the center wall <NUM> may be flanked by airbags <NUM> on both lateral sides.

Each of the airbags <NUM> may be a hose configured to lay flat against the walls <NUM>, <NUM> except when inflated by air. In some embodiments, the airbags <NUM> may be open to atmosphere, and the tendency of the airbags <NUM> to flatten may push air out of the airbags <NUM>. For example, and as shown in <FIG>, the forward end of each airbag <NUM> may be open to atmosphere. Each airbag <NUM> may be connected to an air supply <NUM>, represented in <FIG> as a pneumatic cylinder <NUM>. The air supply <NUM> may be configured to provide air to the airbag <NUM> to inflate the airbag <NUM>. Inflation of the airbag <NUM> may push accumulated crop material away from the wall <NUM>, <NUM> against which the airbag <NUM> is located. Because crop material may tend to accumulate toward one side or the other of each section of the chaffer <NUM>, the air supply(ies) <NUM> may be configured to only inflate airbags <NUM> on one side of each section at one time. In some embodiments, and as depicted in <FIG>, the air supply <NUM> may include a compressor <NUM>, and a valve <NUM> (e.g., a solenoid valve) may control flow from the compressor <NUM> to the airbag <NUM>. In some embodiments, the compressor <NUM> may be a compressor on-board the combine harvester <NUM> and configured to provide pressurized air for various combine operations.

<FIG> illustrates inflation of the airbag <NUM> by the air supply <NUM>. The air supply <NUM> may be configured to inflate the airbags <NUM> fast enough to cause the crop material accumulating near the airbags <NUM> to bounce outward toward the center of the respective sections of the chaffer <NUM>. In some embodiments, the air supply <NUM> may be configured to inflate the airbags <NUM> at the same frequency as the vibration frequency of the chaffer <NUM>. Thus, when the chaffer <NUM> reaches a preselected point in its vibration cycle, some of the airbags <NUM> may inflate. The timing of the inflation may be selected based on modeling or measurement of crop flow in the chaffer <NUM>. If the air supply <NUM> is controlled by mechanical means (e.g., the pneumatic cylinder <NUM>), movement of the chaffer <NUM> may drive movement of the control means. Though the air supply <NUM> is depicted near the rear of the chaffer <NUM> in <FIG>, the air supply <NUM> may be at any selected location in the combine harvester <NUM> with appropriate flow lines.

The chaffer <NUM> typically vibrates at a preselected frequency, such as a frequency in a range from about <NUM> to about <NUM>. For example, the chaffer <NUM> may vibrate at about <NUM>. The airbags <NUM> may be inflated at the top dead center position of the chaffer <NUM>, such that the crop material in the chaffer <NUM> is becoming mostly airborne at the time the airbags <NUM> inflate. This may enable the airbags <NUM> to more effectively spread the crop material across the width of the chaffer <NUM>.

In some embodiments, and as shown in <FIG>, each airbag <NUM> may be between and in contact with a corresponding wall <NUM>, <NUM> and a biasing member <NUM>, which biasing member <NUM> urges the airbag <NUM> toward the wall <NUM>, <NUM>. For example, the biasing member <NUM> may include a spring, a wire, a cord, etc. When the airbag <NUM> is inflated, the biasing member <NUM> may tend to push the air out of the airbag <NUM> and push the airbag against the wall <NUM>, <NUM>. Thus, the biasing member <NUM> in combination with the air supply <NUM> may cause deflation and reinflation of the corresponding airbag <NUM> with a preselected speed and regularity. In other embodiments, the biasing member <NUM> may be within the airbag <NUM> or surrounding the airbag <NUM>, yet still shaped and positioned to return the airbag <NUM> to a deflated position against the wall <NUM>, <NUM>.

As illustrated in <FIG>, the chaffer <NUM> may include movable rigid members <NUM>, and inflation of each airbag <NUM> may cause movement of a corresponding rigid member <NUM>. When the airbag <NUM> moves the rigid member <NUM>, the rigid member <NUM> in turn pushes the crop material outward. The use of a rigid member <NUM> may cause a preselected amount of movement of crop material with a relatively smaller airbag <NUM> (e.g., shorter, smaller diameter, etc.) than the use of an airbag <NUM> alone. The rigid member <NUM> may also perform the function of the biasing member <NUM> shown in <FIG>, such as due to the weight of the rigid member <NUM> leaning upon the airbag <NUM>. The rigid member <NUM> may be partially fixed to the chaffer <NUM>, such as at a hinged joint with the wall <NUM>, <NUM> or the base <NUM>. In some embodiments, the biasing member <NUM> and the rigid member <NUM> may be used together. The rigid member <NUM> may be any selected material, such as a metal (e.g., steel, aluminum, etc.), a polymer, or any combination of materials. For example, the rigid member <NUM> may be a generally planar metal plate.

<FIG> illustrates another embodiment of an airbag <NUM>' that is configured to have an uninflated shape that is rippled. When the airbag <NUM>' inflates, the ripples smooth out, pushing crop material outward across the chaffer <NUM>. In other embodiments, the rigid member <NUM> (<FIG>) may be a rippled sheet of material, and the airbag <NUM> or <NUM>' may push the rigid member <NUM> outward.

<FIG> are simplified cross-section views of a portion of another chaffer <NUM>' having rigid members <NUM> adjacent to a center wall <NUM>. It should be understood that a similar arrangement could be adjacent to the left and right side walls <NUM>, with just one rigid member <NUM> next to each side wall <NUM>. Each rigid member <NUM> is associated with an actuator <NUM> configured to move that rigid member <NUM> away from and/or toward the wall <NUM>, <NUM>. For example, the actuator <NUM> is depicted as a rotating camshaft. When a lobe of the camshaft rotates toward the rigid member <NUM>, as shown in <FIG>, the rigid member <NUM> moves outward in a direction X. In some embodiments, the rigid members <NUM> may be hinged to the wall <NUM>, <NUM>, or to the perforated base <NUM> of the chaffer <NUM>'. The actuators <NUM> may operate independent of one another, such that the rigid member s158 move independent of one another. That is, the rigid member <NUM> on one side of the center wall <NUM> may move, while the rigid member <NUM> on the other side of the center wall <NUM> remains stationary.

In some embodiments, the sieve <NUM> may also include airbags <NUM> and/or rigid members <NUM> to promote even distribution of crop material across the sieve <NUM>, as described above with respect to the chaffer <NUM>.

Whether in the chaffer <NUM>, the sieve <NUM>, or both, the airbags <NUM>, <NUM>' and/or rigid members <NUM> may promote improved separation of crop material. In particular, by keeping the crop material spread across the width of the chaffer <NUM> and/or the sieve <NUM>, the cleaning system of the combine harvester <NUM> may operate closer to its design capacity even on sidehills. Thus, the combine harvester <NUM> may travel through and harvest hilly agricultural fields at a faster speed than conventional harvesters. This may yield agronomic benefits in the form of fewer operators and machines required to harvest fields, lower fuel use, higher quality grain, etc..

The inflation of the airbags <NUM>, <NUM>' and/or movement of the rigid member <NUM> may be controlled by a control system including the controller <NUM> of the combine harvester <NUM>. For example, sensors <NUM> (<FIG>) may be disposed under or over the chaffer <NUM> and/or sieve <NUM> to detect the flow of air and/or solid material, or may be disposed anywhere on the combine harvester <NUM> to detect the angle of the combine harvester <NUM> with respect to gravity. The controller <NUM> may use information about flow rates or the angle of the combine harvester <NUM> to adjust which airbags <NUM>, <NUM>' inflate and/or which rigid members <NUM> move to achieve a selected material distribution within the cleaning system <NUM>. The controller <NUM> may also adjust the timing of inflation of the airbags <NUM>, <NUM>' and/or movement of the rigid members <NUM>.

<FIG> is a simplified flow chart illustrating a method <NUM> of using the combine harvester <NUM> to harvest a crop in an agricultural field. In block <NUM>, cut crop material (e.g., grain mixed with chaff) is passed to a chaffer. Typically, the cut crop material is harvested with a harvesting header, and threshed in the threshing system <NUM> before being passed to the chaffer <NUM> (see <FIG>).

As indicated in block <NUM>, air is directed upward and rearward through the chaffer. The chaffer is also vibrated, indicated by block <NUM>.

Block <NUM> represents inflating at least one airbag with an air supply to distribute the cut crop material laterally across the chaffer. In some embodiments, this act may be performed only when the combine harvester <NUM> is on a sidehill. In other embodiments, this act may be performed even when the combine harvester <NUM> is level.

In blocks <NUM> and <NUM>, respectively, the grain is passed downward through the chaffer, and the chaff is transferred rearward, and ultimately, out of the combine harvester <NUM>.

Though depicted as a flow chart, the actions in <FIG> may be performed concurrently, and in some embodiments, some actions may be omitted.

All references cited herein are incorporated herein in their entireties. If there is a conflict between definitions herein and in an incorporated reference, the definition herein shall control.

Claim 1:
A cleaning system (<NUM>) for a combine harvester (<NUM>), the cleaning system (<NUM>) comprising:
a chaffer (<NUM>) comprising:
a perforated base (<NUM>); and,
a plurality of longitudinal lateral walls (<NUM>); characterised in that the chaffer further comprises:
a plurality of airbags (<NUM>), each disposed adjacent to a lateral wall of the plurality;
a blower (<NUM>) configured to direct air rearward and upward through the chaffer (<NUM>); and
an air supply (<NUM>) configured to inflate at least one of the airbags (<NUM>).