WO2012167042A2

WO2012167042A2 - Grain processing apparatus, system and method

Info

Publication number: WO2012167042A2
Application number: PCT/US2012/040412
Authority: WO
Inventors: Erv LENTZ; Mounir NJAH; Roger SALWAY
Original assignee: Compatible Technology International
Priority date: 2011-06-02
Filing date: 2012-06-01
Publication date: 2012-12-06
Also published as: WO2012167042A3

Abstract

A grain processing system can include a stripper portion, a thresher portion, or a winnower portion. The stripper portion can use a coordinated roller assembly to receive a grain panicle or stalk via an in-feed hole. The stripper portion can separate the seed from the stalk of the received panicle. The thresher portion can include a compliant paddle and screen to separate the seed from the chaff. The winnower portion can include a feeder, an aspirator, and a separator. The feeder can introduce a metered mixture of seeds and chaff into the separator. The aspirator can be used to direct an airflow into the separator. The airflow and the orientation of the separator can be adjusted to optimize separation of the seeds and chaff. The grain processing system can be manually operated, such as using one or more crank arms

Description

GRAIN PROCESSING APPARATUS, SYSTEM AND METHOD

PRIORITY CLAIM AND RELATED APPLICATIONS

This application claims the benefit under 35 U.S. C 119(e) of the following United

States Provisional Patent Application, the contents of which is incorporated herein by reference in its entirety: US Provisional Patent Application Serial Number 61/492,598 filed June 2, 2011. TECHNICAL FIELD

The present invention relates to grain processing equipment and methods.

BACKGROUND

Cereals and grains are the cornerstones of many of the world's diets. To obtain edible portions of grains, many techniques can be used to separate seed from chaff. The techniques can include manual processes, automated processes, or some combination of manual and automated processes.

One particularly important cereal crop is pearl millet (Pennisetum glaucum), which is planted on some 14 million hectares in Africa and 14 million hectares in Asia. At least 500 million people depend on pearl millet for their daily lives. Pearl millet is perhaps the best of all "life-support" grains. It is easy to grow and thrives where conditions are particularly harsh, producing reliable yields in regions too hot and too dry to consistently support good harvests of maize, sorghum, or other crops. Also, pearl millet suffers less from disease than sorghum, maize, or other grains, and is less susceptible to insect infestation than some other grains. These characteristics of pearl millet allow it to grow in regions of Africa, among other regions, that are desperately in need of food aid and where agricultural development will have great humanitarian benefits. It is used mainly as ground flour, in dough, or as a rice-like grain. It is used in a variety of foods, including unfermented breads (e.g., roti), fermented foods (e.g., kisra, gallettes, etc.), thin and thick porridges (e.g., toh), and steam- cooked dishes (e.g., couscous).

It can be an extremely difficult, labor intensive, and time consuming to process cereal grains, such as pearl millet, into useable food. As an example, a pearl millet grain panicle contains a central rachis (stalk or shaft) with floral tissue ("florets") and grain attached to it. Manipulation of the panicle can often break the spikelets (florets and grain) off of the stalk. Traditional processing requires farmers and workers— often women— to manually dislodge the grain and florets from the stalk, and to manually separate the edible seed from other plant debris, generically referred to as chaff. If grains are broken or cracked during the process, oxidation of the unsaturated fatty acids in pearl millet can result in rancidity and off- flavors that can render the broken grain distasteful or inedible.

Traditional processing involves extensive manual labor that can include breaking the pearl millet apart by a manual mortar and pestle action, such as in a hollowed out log, or threshed out on the ground. In some instances pearl millet panicles may be lain across pathways traveled by humans and/or animals for threshing, relying upon this "foot" traffic to break the florets and grain away from the stalk. Using this approach, many health concerns are presented by unsanitary processing that can result in dirt and other debris, including animal feces, being mixed in with the pearl millet grain. Once separated from the stalk, the grain and florets are gathered up, along with attendant dirt and debris, and can be separated from the chaff by winnowing in the open air. In some cases, the person conducting the winnowing tosses the grain and debris into the air and uses wind to separate the chaff from the seed. With this practice, much of the grain can be lost, broken or contaminated.

Additional health concerns are presented by the worker breathing in the fines formed in the chaff and debris. Traditional grain processing methods have served the communities that employ them; but the traditional methods have low yields, are time consuming and inefficient, and present sanitation and health risks.

Some farmers may opt to take their grain to a commercial thresher, which can add significant expense and time to the process. Others may sell their grain because they lack the means to process the grain efficiently into flour, and may later buy, at significant expense, flour prepared from the very grain they grew.

At a cost, efficient modern equipment and methods are available to extract the grain from pearl millet; however, none previously existed that were suitable for independent use by small landholders or family farmers to process pearl millet by means other than the traditional labor and the time-intensive methods described above. While industrial-grade automated threshers can quickly process pearl millet, they are expensive, require a combustible fuel or electricity to run, and are subject to costly maintenance and repairs. Development of simple technologies to facilitate grain stripping, threshing, winnowing, and grinding can have a significant impact on crop yield, can increase farmer income and food production, and can help the farmers move from subsistence farming to establishing small businesses.

SUMMARY OF THE INVENTION

The invention provides components of a grain processing system, the grain processing system, and associated methods.

In an embodiment of the invention, a grain processing system is provided. The grain processing of this embodiment comprises a stripper portion, a thresher portion, or a winnower portion, or phrase alternatively, a stripper, a thresher and a winnower. The stripper portion can use a coordinated roller assembly to receive a grain panicle or stalk via an in-feed hole. The stripper portion can separate the seed from the stalk of the received panicle. The thresher portion can include a compliant paddle and screen to separate the seed from the chaff. The winnower portion can include a feeder, an aspirator, and a separator. The feeder can introduce a metered mixture of seeds and chaff into the separator. The aspirator can be used to direct an airflow into the separator. The airflow and the orientation of the separator can be adjusted to optimize separation of the seeds and chaff. The grain processing system can be manually operated, such as using one or more crank arms.

In an embodiment of the invention, a stripper or stripper portion is provided. The stripper of this embodiment comprises a roller assembly, a stripper crank arm, and a front plate roller. The roller assembly comprises a first roller having a first longitudinal axis and a second roller having a second longitudinal axis. The first and second longitudinal axes are substantially parallel, and the second roller is spaced apart from the first roller to form a longitudinal gap therebetween. The stripper crank arm is coupled to at least one of the first roller or the second roller, and the front plate includes at least one in-feed hole. The front plate is disposed near the first and second rollers such that the at least one in-feed hole is aligned with the longitudinal gap between the first and second rollers. An axis of the front plate is substantially parallel to the first and second longitudinal axes.

In some embodiments of the invention, the stripper portion may be: 1) configured to rotatably drive at least one of the first roller or second roller; 2) provide with a handle that is coupled to a stripper crank arm configured to rotatably drive the first roller in response to a manual cranking motion applied to the handle; 3) provided with a front plate that includes an in-feed hole that is sized to receive a grain panicle; 4) provided with a front plate that includes multiple in- feed holes that are aligned with the longitudinal gap between the first and second rollers; 4) provided with a front plating having multiple in-feed holes that have different diameters or that are otherwise differently sized or shaped; 5) provided with a roller assembly and front plate that are fixedly coupled together; 6) provided with a housing that is configured to at least partially surround the roller assembly; 7) provided with a shield assembly configured to substantially surround the front plate and that may be optionally configured to direct material stripped from a grain panicle toward a catch basin; or 8) provided with combinations of the previously listed stripper components or features.

In an embodiment of the invention, a method is provided for using or operating the stripper. The method of this embodiment includes the steps of: stripping grain from a panicle can be accomplished using the stripper portion by receiving an end portion of an unprocessed grain panicle, via an in-feed hole of a grain stripper, in a gap between a pair of rollers, rotating at least one of the rollers to draw the unprocessed grain panicle through the in-feed hole, and separating a grain portion from a stalk portion of the unprocessed grain panicle.

In another embodiment of the invention, a thresher or a thresher portion is provided. The thresher of this embodiments is comprised of a thresher hopper and a threshing assembly. The thresher hopper is coupled to the threshing assembly and configured to the feed contents of the thresher hopper into the threshing assembly. The threshing assembly can include, among other components, a wheel assembly, a thresher crank arm coupled to the wheel assembly, a paddle coupled to the wheel assembly, and a perforated screen. The paddle is oriented at an angle relative to the perforated screen.

In some embodiments of the invention, the thresher or thresher portion may be provided with: 1) a paddle that includes an angled portion that approaches and tapers toward the perforated screen; 2) a threshing assembly that includes two or more paddles coupled to the wheel assembly, wherein each of the paddles includes an angled portion that approaches and tapers toward the perforated screen; 3) a paddle that exerts a force against the perforated screen; 4) a paddle that includes a ridged portion on a side of the paddle that faces the perforated screen; 5) a paddle having a ridged portion having multiple ridges that are sized to accept individual grains (e.g., pearl millet) between the ridges; 6) a wheel assembly that is rotatably driven in response to a cranking motion applied at the thresher crank arm; 7) a handle coupled to the thresher crank arm, wherein the wheel assembly can be rotatably driven in response to a manual cranking motion applied to the handle; 8) a thresher assembly housing to contain the threshing assembly; 9) a thresher assembly housing that is at least partially open along a bottom portion, and the perforated screen is disposed at least partially over the bottom portion; 10) at least one paddle that is a compliant paddle assembly; or 11) combinations of the previously listed thresher components or features.

In another embodiment of the invention, a method is provided for using or operating the thresher or thresher portion. The method of this embodiment includes the steps of:

receiving a grain mixture in a thresher hopper, receiving the grain mixture in a threshing assembly via the thresher hopper, pressing the grain mixture against a first side of a perforated screen using an angled paddle inside of the threshing assembly, passing the grain mixture between the perforated screen and the angled paddle inside of the threshing assembly, and receiving a seed portion of the grain mixture on a second side of the perforated screen, wherein the second side is opposite the first side of the perforated screen.

In yet another embodiment of the invention, a winnower or a winnower portion is provided. The winnower of this embodiment is comprised of a feeder, an aspirator, and a separator. The feeder is coupled to the separator, and the feeder is configured to introduce a grain mixture into the separator. The aspirator is coupled to an end portion of the separator and the aspirator is configured to introduce an airflow into the separator.

In some embodiments of the invention, the winnower or winnower portion can be provided with: 1) a winnower crank arm coupled to the feeder and configured to

mechanically drive the feeder; 2) a winnower crank arm coupled to the aspirator and configured to mechanically drive the aspirator; 3) a winnower crank arm coupled to the feeder and the aspirator, wherein the crank arm mechanically drives the feeder and the aspirator such that a rate of operation of the feeder is different than a rate of operation of the aspirator; 4) a feeder having a portion that is substantially transparent; 4) a separator having a portion that is substantially transparent; 5) a feeder that comprises a winnower hopper and an auger conveyer configured to direct the grain mixture from the winnower hopper to the separator; 6) a coupling between the aspirator and the separator that includes a venturi to reduce turbulence of an airflow in the separator; 7) a coupling between the feeder and the separator that includes an overhang portion that facilitates distribution of the grain mixture into the separator; or 8) combinations of the previously listed winnower components or features

In a further embodiment of the invention, a method of using or operating the winnower is provided. The method of this embodiment comprises the steps of: receiving a grain mixture in a feeder of a winnower system, introducing the grain mixture into a separator of the winnower system using the feeder, and providing an airflow from an aspirator of the winnower system into the separator, wherein the airflow is introduced at a rate sufficient to expel a chaff portion of the grain mixture from the winnower system.

In yet a further embodiment of the invention a grain processing system includes a stripper portion, a thresher portion, or a winnower portion. The stripper portion of this embodiment includes a roller assembly that comprises a first roller having a first longitudinal axis and a second roller having a second longitudinal axis, and the first and second longitudinal axes are substantially parallel, and the second roller is spaced apart from the first roller to form a longitudinal gap therebetween. The stripper portion further includes a separator crank arm, coupled to at least one of the first roller or the second roller, and a front plate including an in-feed hole. The front plate is disposed near the first and second rollers such that the in-feed hole is aligned with the longitudinal gap between the first and second rollers. An axis of the front plate is substantially parallel to the first and second longitudinal axes. The thresher portion of this embodiment includes a thresher hopper and a threshing assembly. The thresher hopper is coupled to the threshing assembly and configured to feed contents of the thresher hopper into the threshing assembly. The threshing assembly includes a wheel assembly, a thresher crank arm coupled to the wheel assembly, a paddle coupled to the wheel assembly, and a perforated screen. The paddle is oriented at an angle relative to the perforated screen and is configured to substantially trap stripped grain between a face of the paddle and the perforated screen. The winnower portion of this embodiment includes a feeder, an aspirator, and a separator. The feeder is coupled to the separator and the feeder is configured to introduce a grain mixture into the separator. The aspirator is coupled to an end portion of the separator and the aspirator is configured to introduce an airflow into the separator. The grain processing system optionally includes a grinder portion configured to grind grain that has been separated from chaff.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description can be more completely understood and appreciated by referring to the following drawings, wherein:

FIG. 1 is a perspective view of a grain processing system according to an embodiment of the invention.

FIG. 2A is a perspective view of a stripper according to an embodiment of the invention. FIG. 2B is a side, cross-sectional view of a stripper according to an embodiment of the invention. FIG. 3A is a perspective view of a thresher according to an embodiment of the invention. FIG. 3B is a perspective view of a thresher according to an embodiment of the invention. FIG. 4 is a perspective view of a winnower according to an embodiment of the invention. FIG. 5 is a perspective view of a feeder section according to an embodiment of the invention. FIG. 6 is a perspective view of an aspirator section according to an embodiment of the invention.

FIG. 7 is a perspective of a separator section according to an embodiment of the invention. FIG. 8 is a perspective view of a grinder according to an embodiment of the invention.

FIG. 9 is a perspective view of a grinder according to an embodiment of the invention.

While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described or illustrated. The invention covers all modifications, equivalents, and alternatives.

DETAILED DESCRIPTION

The following Detailed Description is to be read with reference to the drawings, in which like elements in different drawings may have like reference numbers. The drawings, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of the invention. Skilled artisans will recognize that the given examples have many alternatives that fall within the scope of the invention.

The present invention includes various embodiments of one or more grain processing apparatuses and methods of processing grain using the apparatuses. The various

embodiments of the one or more grain processing apparatuses can be combined in multiple ways to provide a grain processing system.

Figure 1 shows a grain processing system 100 according to an embodiment of the invention that includes a stripper 110, a thresher 200, and a winnower 300. A grinder 400 (not shown) can optionally be included. In some embodiments, the stripper 110 is configured to receive a grain panicle 101 (e.g., comprising one or more grains coupled to a stalk 102). The stripper 110 is used to decouple one or more grains from a stalk portion of the grain panicle 101. The thresher 200 is configured to receive the decoupled grain. The thresher 200 separates a seed, or other edible portion of the grain, from a chaff portion of the grain. The seed and chaff mixture can be fed into the winnower 300. The winnower 300 uses air (e.g., introduced via a blower or fan) to further separate the seed and chaff. Seed separated from the chaff and obtained from the winnower 300 can be milled using a grinder. In Figure 1, a plurality of grain processing paths 10 through an embodiment of the grain processing system 100 illustrate generally a process flow or sequence of an embodiment of the invention that includes entering the stripper 1 10, passing from the stripper 110 to the thresher 200, and passing from the thresher 200 to the winnower 300.

Embodiments of the invention include any one or more of the stripper 110, the thresher 200, and the winnower 300, and may further include an optional grinder 400 (such as shown in Figure 9). For example, the stripper 110 and thresher 200 can be combined or configured such that grain separated from panicle 101 introduced to the stripper 110 can automatically pass to the thresher 200 for further processing. Any one or more of the stripper 110, the thresher 200, the winnower 300, or the grinder 400 can be manually operated (e.g., using a hand crank); or otherwise can be mechanically operated (e.g., with a bicycle-like system pedaled by an operator) or operated automatically as with a motor or engine (e.g., an electric or other motor).

In an embodiment, the stripper 110 minimally includes a roller assembly comprising at least two rollers 122, 124, a housing or plate with a grain in- feed hole 120, and a means for activating the rollers such as a hand crank 112. Referring to Figure 2 A, the stripper 110 is shown in perspective view. In some embodiments, the stripper 110 can be securely supported by or mounted to one or more brackets 115, or can be alternatively or additionally mounted or supported by a work station or table. The stripper 110 can be disposed above a catch basin (not shown) to collect stripped grain. The embodiment of Figure 2A further includes an optional shield assembly 111. The shield assembly 111 can be configured to direct stripped grain toward a catch basin or other vessel. In some cases, because grain stripped from a grain panicle using the stripper 110 can be removed at a high rate, the grain can travel at a high velocity, and/or in unpredictable directions. The shield assembly 111 can be provided to protect an operator of the stripper 110 from propelled grain during the stripping process or to facilitate efficient grain collection.

The embodiment of the stripper 110 of Figure 2A is configured for operation by hand. As illustrated, the stripper 110 can be operated using a stripper crank arm 112. The stripper crank arm 1 12 can be provided with a handle and coupled to a stripper crank shaft 113. An operator can rotate the stripper crank arm 112 to actuate the stripper crank shaft 113, which turns the roller assembly of the stripper 110, as further described in the discussion of Figure 2B below. By rotating the stripper crank arm 112, the roller assembly can engage and draw a grain panicle 101 through the stripper 110, e.g., as via the in-feed holes 120.

In an embodiment, the grain stripper 110 includes one or more grain in- feed holes 120. The in- feed holes 120 can be provided in a front panel of a stripper housing 114. The stripper housing 114 can be made of a rigid material, such as metal, wood, plastic, or other material that will not be deformed by the force of a grain panicle being drawn through a small opening in the material. The in-feed holes 120 can be differently sized to receive differently sized grain panicles. For example, a first in-feed hole can be about 1 cm in diameter, and a second (e.g., adjacent) in-feed hole can be about 2 cm in diameter. An operator can readily determine which of the in- feed holes will be most effective for grain stripping by matching a size of a grain stalk 102 to an appropriate in-feed hole.

As the grain panicle 101 is drawn through an appropriately-sized in-feed hole 120, the grains of the grain panicle 101 will encounter the front panel of the stripper housing 114 that surrounds the grain in-feed hole 120. Because of the force exerted on the individual grains (e.g., or florets or spikelets) of the grain panicle 101 as the grain stalk 102 is drawn through an in-feed hole, the individual grains can be stripped or removed from the grain stalk 102. The stripped material can be directed toward a catch basin, such as using the stripper shield assembly 111, if provided. Depending on the number and spacing of the grain in- feed holes 120, and the strength of the operator, among other factors, more than one grain panicle can be drawn through the stripper 110 at any given time.

In Figure 2B, a side, cross-sectional view of the stripper 110 is shown. In some embodiments, the stripper housing 114 can completely surround the roller assembly of the stripper 110 except for the in- feed holes 120 and an exit port, such as on a side of the stripper 110 opposite the in-feed holes 120. In the embodiment of Figure 2B, the stripper housing 114 can surround or provide five or less of the six sides of the stripper 110, such as to leave at least a rear portion of the stripper 110 open to facilitate removing used stalks from the stripper 110. In addition, leaving at least one side open can facilitate operator access in the case of a jam or other malfunction, or for routine maintenance, such as to lubricate

components of the roller assembly.

In the embodiment of Figure 2B, the stripper crank shaft 113 is coupled to a first sleeve bearing 134. The first sleeve bearing 134 is coupled to a first roller 124. Rotation of the stripper crank arm 112 can be translated into rotational motion of the first roller 124 via the first sleeve bearing 134 to which it is coupled. In some embodiments, a gear assembly can be interposed between the stripper crank arm 112 and the stripper crank shaft 113 or the first roller 124 to facilitate operation of the grain stripper 110, such as by making operation of the grain stripper 110 less physically demanding on the operator.

The embodiment of Figure 2B further includes a second roller 122 and a longitudinal gap 137. The longitudinal gap 137 can be provided between the first roller 124 and the second roller 122. The longitudinal axes of the first roller 124 and the second roller 122 can be substantially parallel (as shown), or the longitudinal axes can form a slight angle. For example, an angled orientation of the first and second rollers 124 and 122 may be desirable if the operator is attempting to concurrently process multiple grain stalks of different sizes.

The first roller 124 and the second roller 122 can be made of various materials, such as plastic or rubber of a moderate durometer (e.g., about 70 Shore A) or coated or covered with such materials. Those skilled in the art will be able to select materials of appropriate durometer or surface texture to grip and draw a grain stalk through the stripper 110 as the crank arm 112 is rotated. Importantly, the material for the rollers can be selected such that the rollers are resistant to extreme environmental conditions, such as extreme temperatures (e.g., in excess of 43 degrees Celsius) and temperature fluctuations.

The first roller 124 and the second roller 122 can be coupled to first sleeve bearing 134 and a second sleeve bearing 132, respectively. For example, the first roller 124 can be coupled to the first sleeve bearing 134 using a spring pin 123 such as is shown positioned in second roller 122, or the first sleeve bearing 134 can otherwise be secured, permanently or removably. The coupling between the first roller 124 and the first sleeve bearing 134 via the spring pin 123 can cause the first roller 124 to rotate when the first sleeve bearing 134 rotates.

In an embodiment, a location of the second roller 122 can be adjustable. A roller adjuster 130 can be used to change the location or relative position of the second roller 122, such as in the vertical plane of Figure 2B. One reason to change the location of the second roller 122 relative to the first roller 124 is to adjust the width of the longitudinal gap 137 to accommodate various grain stalk sizes or to provide an angled orientation.

In the embodiment of Figure 2B, the roller adjuster 130 is depicted as a pair of threaded eye bolts, coupled to a driven shaft 136 or bushing associated with the second roller 122. As an operator rotates the eye bolts, the second roller 122 can be caused to toward or away from the first roller 124. This adjustment can be performed with other adjustment means known to those skilled in the art. For example, the roller could be adjusted using adjustment means accessed from the side of the stripper housing 114. In some embodiments, the second roller 122 can be in a fixed location, and the first roller 124 can be adjustable. In some embodiments, the first roller 124 and the second roller 122 can each be adjustable.

Other mechanisms known to those skilled in the art can be used for the roller adjuster 130.

In an embodiment, a gear assembly 133 can optionally be coupled to the stripper crank shaft 113 or the driven shaft 136. The gear assembly 133 can cause the driven shaft 136 to rotate when the stripper crank arm 112 is rotated (e.g., by an operator or a motor) and imparts rotational motion to the stripper crank shaft 113. In some embodiments, the gear assembly 133 can be configured such that the first roller 124 and the second roller 122 operate at different rotational speeds for the same operator input at the stripper crank arm 112. A gear assembly can be positioned on either or both sides of stripper 110.

In some embodiments, the stripper 110 may have three or more rollers, such as corresponding to two or more rows of in-feed holes. In some embodiments, the stripper 110 can be configured to feed a processed stalk (e.g., a stalk from which grain has been removed) to another downstream process or device.

In another embodiment of the invention, a thresher is provided. Referring to Figure

3A, the thresher 200 is shown in a perspective view. The thresher 200 can be configured to separate chaff, e.g., seed coverings, florets, or other debris, from an edible portion of a grain, such as a seed. The thresher 200 includes a thresher housing 201, one or more thresher cover panels 202, and a thresher hopper 203. In the embodiment of Figure 3 A, the thresher housing 201 can optionally be secured to a seed catch basin 212 using a thresher mounting bracket 210, or it can be secured to a work table or other support. The thresher 200 can include a thresher crank arm 209, depicted with a handle, coupled to a thresher crank shaft 208, or otherwise configured for manual or automatic operation to impart rotational motion to the thresher crank shaft 208. The thresher crank shaft 208 can be coupled to a rotor and bushing assembly 206 to translate rotation of the thresher crank shaft 208 into rotational movement of a threshing wheel assembly 204 inside the thresher 200.

The thresher hopper 203 can be configured to direct stripped grain toward an internal portion of the thresher 200 that includes one or more paddles 207. In the embodiment of Figure 3 A, the thresher hopper 203 is configured to direct stripped grain through a side of the thresher 200 in a direction that is perpendicular to an axis of rotation of the threshing wheel assembly 204. The stripped grain is presented to an inner surface of a semi-circular perforated screen 205. The stripped grain is then threshed and pushed to an outer, opposing side of the perforated screen 205. Other configurations of a thresher hopper can be used. For example, the embodiment of Figure 3B shows a thresher 250 that includes a thresher housing 251, one or more thresher cover panels 252, and a thresher hopper 253. In the embodiment of Figure 3B, the thresher housing 251 can optionally be secured to the seed catch basin 212 using a thresher mounting bracket 260. The thresher hopper 253 can be configured to direct stripped grain toward an internal portion of the thresher 250 that includes one or more paddles. In the embodiment of Figure 3B, the thresher hopper 253 is configured to direct stripped grain through a side of the thresher 200 in a direction that is parallel to an axis of rotation of the threshing wheel assembly 204. The stripped grain is presented to an inner surface of a circular perforated screen 255. The stripped grain is then threshed and pushed to an outer, opposing side of the perforated screen 255. Among other benefits, the configuration of the thresher hopper 253 and the circular perforated screen 255 in the embodiment of Figure 3B can increase yield by increasing the surface area over which the incoming grain can be introduced to the thresher and threshed.

Referring again to the embodiment of Figure 3 A, a paddle can be mounted to the threshing wheel assembly 204. A paddle 207 can include a ridged or semi-ridged flap that can press up against a perforated screen 205. In some embodiments, the paddle 207 can be at least partially reinforced with a stiff material (e.g., a metal) to ensure the paddle 207 maintains a desired orientation relative to the perforated screen 205. An angular orientation of the paddle 207 relative to the perforated screen 205 can cause grains to be received between the perforated screen 205 and the paddle 207. A ridged portion of the paddle 207 can further encourage grain to be received between the perforated screen 205 and the paddle 207. In some embodiments, the paddle 207 can be spaced a particular distance from the perforated screen 205, or the paddle 207 can physically contact or come very nearly in physical contact with the perforated screen 205. Such distances can be preset, or adjustable, depending on the type or size of grain to be received.

In an embodiment of thresher 200, the paddle 207 can be a flexible, or compliant, paddle assembly, and can be coupled to the wheel assembly 204. A compliant paddle assembly can include a paddle portion that is not fully rigid, i.e., can bend toward or away from the perforated screen 205. A compliant or flexible paddle assembly can include a rubber paddle portion, and can optionally include a stiffening or supporting feature to increase the rigidity (e.g., to decrease compliance or flexibility) of the paddle assembly forming paddle 207 in some embodiments. A paddle 207 formed of compliant or flexible paddle assembly can exert a variable force on grain caught between the paddle 207 and the perforated screen 205. The variable force applied is in part a function of a displacement distance, the distance the paddle 207 is spaced away from the perforated screen 205. For example, when a larger grain is caught between the paddle 207 and the perforated screen 205, the paddle 207 can be displaced or spaced away a first distance, and a first force can be exerted upon the grain as the wheel assembly rotates. When a smaller grain is caught between the paddle 207 and the perforated screen 205, the paddle 207 can be displaced a second distance that is less than the first distance, and a second force that is less than the first force can be exerted upon the grain as the wheel assembly rotates.

In some embodiments of thresher 200, multiple paddles can be coupled to the threshing wheel assembly 204. The multiple paddles can be the same, or they can be differently sized or shaped. For example, a first paddle can include a ridged surface with spaced ridges, and a second paddle can include a ridged surface with differently spaced ridges. In an embodiment, the multiple paddles can be multiple compliant paddle assemblies, having the same or different levels of compliance or flexibility.

As an operator rotates the thresher crank arm 209 and causes the threshing wheel assembly 204 and paddle 207 to move, grain can be caught between the paddle assemblies 207 and the screen 205. An angular orientation of the paddle 207 can be adjusted or optimized depending on the size of the grain to be processed. In addition, a ridge depth on the screen-side of the paddle 207 can be adjusted or optimized. In an embodiment of a paddle that is optimized for threshing pearl millet, the ridge depth can be about 2 to 5 millimeters. Multiple different ridge depths can be accommodated on a single paddle, or different paddles can use different ridge depths to enable more efficient threshing of different sizes of grains.

In operation, as the threshing wheel assembly 204 rotates, the paddle 207 can be rotated and individual grains can be pressed against the perforated screen 205 by the paddle 207. As the grain is scraped across the perforated screen 205, the chaff can be removed, and the seed can pass through the perforated screen 205, generally with little to no breaking or cracking the grain. Some of the removed chaff may also pass through the perforated screen 205.

The configuration of the perforated screen 205 can be selected depending on the size of a grain to be processed. Those skilled in the art will readily identify an appropriate mesh size based on the size of a grain to be processed. By way of a non-limiting example, an 1/8 inch mesh screen can be selected for processing of pearl millet. The mesh size of the perforated screen 205 must be large enough to allow individual seeds or grain, when separated from the chaff, to pass through, but the perforated screen 205 is preferably not large enough to pass seeds which are still coupled to the chaff. In some embodiments, the thresher 200 can be configured to accommodate multiple different perforated screens, such as can be changed by an operator. In some embodiments, a perforated screen can include perforations or holes of various sizes.

In some embodiments, the perforated screen 205 can be easily changed by an operator. In the embodiment of Figure 3, the perforated screen 205 as illustrated is a mounted semicircular (180° arc) screen material that is secured within the thresher housing 201 using a pair of nuts and bolts 213 or other appropriate fastening means. In other embodiments, the perforated screen 205 can be formed of one or more sections of screen material, and can extend less than 180° (e.g., preferably at least about 90°) or can extend more than 180° (e.g., up to a full circle or 360°).

In the illustrated embodiment of the thresher 200, when the pair of nuts and bolts 213 is removed, the perforated screen 205 can be removed from the thresher 200, and a different, second screen can be installed in its place, such as to replace a used screen or to install a screen of a particular mesh size. Other mechanisms or other appropriate fastening means can be used to secure the perforated screen 205 within the thresher housing 201, such as a single nut and bolt installed parallel to an axis of the thresher 200. In some embodiments, the perforated screen 205 can be permanently affixed to the thresher housing 201. In some embodiments, the perforated screen 205 can include a burr or other structure at some or all of the perforations on the paddle-assembly side of the perforated screen 205. A burr can help to partially macerate the grain to separate a usable portion from the chaff.

Separated grain and chaff can fall through the perforations in the perforated screen 205 into a seed catch basin 212 or other receptacle. The seeds and some residual chaff are then available for additional processing, such as winnowing, to separate the chaff from a usable portion of the grain. After winnowing, the usable portion can be ground to produce flour, cracked, or otherwise prepared.

In Figure 4, an embodiment of the winnower 300 is shown. The winnower includes, among other components, a feeder section 301, an aspirator section 302, a separator section 303, and a collector 321. The winnower 300 separates the mixture of grain and chaff and can be manually operable (e.g., by a single individual) or automatically operable (e.g., by a motor or other machine). In some embodiments, the winnower 300 can be mechanically driven by a hand crank that simultaneously drives both an aspirator (blower) and an automatic feeder (auger). In an embodiment, a feeder provides a mixture of grain and chaff (e.g., obtained using the thresher 200 and collected in the catch basin 212) into a separator where an airflow from an aspirator or blower winnows the mixture. Lighter chaff can be carried up and out of the separator by air while heavier grain can fall down into the removable collector 321.

Figure 5 illustrates an embodiment of the feeder section 301. The feeder section 301 can include a hopper 304, a feeding chamber 305, and/or an auger conveyer 306. The hopper 304 can serve as a container to hold a mixture of grain and chaff. In an example, the hopper 304 can be funnel shaped, and can be configured to direct the mixture into the feeding chamber 305. In the embodiment of Figure 5, first and second differently sized reducers 307 and 308 are used to form the hopper 304. In some embodiments, a plurality of reducers can be removably included in the feeder section 301. For example, a larger reducer (e.g., the first reducer 307) can be removed when processing smaller amounts of grain and chaff. Larger hoppers can be formed by attaching any number of hopper reducers to reducer 308, or by replacing reducer 308 with a larger reducer to process larger amounts of grain.

A junction 309 is provided between the hopper 304 and the feeding chamber 305; and in some embodiments, it can be curved as shown in Figure 5 to minimize jamming at or before the feeding chamber 305. In an embodiment of the winnower 300, the feeding chamber 305 can include the auger conveyer 306. Once a mixture of grain and chaff has entered the feeding chamber 305, the auger conveyer 306 can feed the mixture into a separation chamber 323. In some embodiments, the separation chamber 323 and/or the feeding chamber, among other components, can be made in whole or in part of a transparent material (e.g., a transparent plastic material). If a transparent material is used, an operator can visually observe material flow within the apparatus during operation, for example to identify a clog, or to adjust a speed of the airflow.

The auger conveyer 306 includes an auger fin portion (e.g., a helical metal auger) and an auger shaft 311. A hand crank 316 can be configured to drive the auger conveyer 306 via the auger shaft 311 and, optionally, a series of pulleys. In an embodiment, the auger shaft 311 can be fixedly coupled to a first auger pulley 312 and to a blower pulley 313, any one or both of which can be coupled to and driven by the hand crank 316. Any two or more pulleys can be connected by a belt 314 or series of belts such that when the hand crank 316 is turned, the pulleys rotate the auger shaft 311 and drive the auger conveyer 306. The auger pulley 312 and the blower pulley 313 can be selected such that a mixture of grain and chaff can be introduced into the separation chamber 323 at a rate that is proportional or otherwise adapted to the velocity or magnitude of the airflow generated by a blower 317. A junction 315 between the feeding chamber 305 and the separation chamber 323 can be made of a transparent material in whole or in part so the operator can observe or monitor the rate of feeding and adjust the speed of operation accordingly.

Figure 6 shows an embodiment of the aspirator section 302. The aspirator section 302 can include, among other components, the blower 317 and one or more airflow conduits 318. The blower 317 can be operated using the hand crank 316, as previously described using the same hand crank 316 used to operate the auger conveyer 306. In an embodiment, when the hand crank 316 is turned, the blower 317 can be caused to generate or introduce an airflow into the airflow conduits 318. In yet another embodiment, the blower 317 may be actuated using a first hand crank, and the auger conveyor 306 can be actuated by another hand crank or actuator. The airflow conduits 318 can direct at least a portion of the generated airflow into a grain collection conduit 319. A screen 320 (shown in Figure 6 as a dashed line), can be optionally disposed in one or more of the airflow conduits 318, can partition an outlet of an airflow conduit 318 at its junction with the grain collection conduit 319. The screen 320 can be configured to permit an airflow to pass from the blower 317, through the airflow conduit 318, and into the grain collection conduit 319. The screen 320 can prevent grain and/or chaff from entering the airflow conduits 318 by selecting an appropriately-sized mesh that would be of smaller mesh than the mesh used for perforated screen 205 or smaller than the grain or seed being processed (e.g., about 1/16 inch).

Figure 7 illustrates an embodiment of the separator section 303 according to the invention. The separator section 303 can include, among other components, a collector or collection jar 321, a grain collection conduit 319, an optional venturi 322, the separation chamber 323, an exhaust conduit 324 and an exhaust area 325. In an embodiment according to the invention, an airflow from the aspirator section 302 can be provided to the grain collection conduit 319 and directed upward toward the separation chamber 323. The grain collection conduit 319 and the separation chamber 323 can be similarly or differently sized. For example, they can be of the same or different internal diameters or cross-sectional areas. To minimize turbulence in the airflow entering the separation chamber 323, the optional venturi 322 can be used. The venturi 322 can be a device inserted at the junction of the conduit 319 and separation chamber 323 or incorporated into either of these components. The venturi is configured to reduce airflow turbulence that may be introduced into the winnower at junctions between airflow conduits that have different cross-sectional areas. The venturi 322 can be formed using a pair of cone-shaped conduits that have different cone angles (e.g., using an entry cone with a 30 degree mouth or an exit cone with a 5 degree mouth). An orifice plate can optionally or alternatively be used. However, the venturi 322 is preferred because significant energy losses can be suffered using an orifice plate.

As described above, the feeder section 301 can be used to introduce a mixture of grain and chaff into the separation chamber 323. In some embodiments, the auger conveyor 306 can be provided with an overhang 326 to facilitate introduction of the grain and chaff mixture from the feeding chamber 305 into separator chamber 323. The overhang 326 can, for example, help to prevent or minimize blow-back of the mixture into the feeding chamber 305. The overhang 326 can be an extension of the feeder section 301 or feeding chamber 305 into the separation chamber 323, such as a ledge.

An airflow in the separation chamber 323 (e.g., provided using the aspirator section 302 and the blower 317) can carry a lighter chaff portion of the grain and chaff mixture up and out of the separator section 303, and the chaff portion may further pass through the exhaust conduit 324. The heavier grain can fall through the grain collection conduit 319 and into the collector or collection jar 321. In an embodiment, the separation chamber 323 and/or the grain collection conduit 319 can, at least in part, be made of a transparent material to permit an operator to monitor the winnowing process and, in some examples, to adjust a rate of operation. For example, if an operator observes that grain is being blown out of the separation chamber 323 along with the chaff, then the speed of the airflow can be reduced (e.g., by more slowing rotating the hand crank 316 or other actuator) to prevent further loss of grain. Conversely, if an operator observes that chaff is entering the grain collection conduit 319, then the speed of the airflow can be increased to prevent the chaff from entering the collection jar 321. By appropriately scaling lengths or portions of the grain collection conduit 319 and/or the separation chamber 323 that is made of a transparent material, an operator can be afforded time to observe the winnowing process and adjust operation of the hand crank 316 and the blower 317.

The exhaust conduit 324 can be configured to direct the exhaust air and chaff away from the separation chamber 323. In some embodiments, the exhaust conduit 324 can be curved, such as to prevent chaff from falling back into separation chamber 323. In the embodiment of Figure 7, for example, the exhaust conduit 324 is curved or arched. The exhaust air and chaff can be directed into the optional exhaust area 325 for collection or isolation of the chaff or other lightweight particulate matter. In some embodiments, the exhaust area 325 is comprised of an exhaust screen or gas-permeable bag-like component to catch or direct exhaust materials for collection. Isolating the chaff and particulate matter can protect an operator, who may be sensitive or allergic to the chaff and particulate matter, from inhaling the particulate matter. Further, isolating the chaff and particulate matter may permit an operator to remain attentive to the winnowing process and speed of the blower 317 instead of being concerned with protecting himself or herself from the exhaust. If an exhaust screen or exhaust bag is used, the screen or bag can be at least partially open at one end to minimize a buildup of pressure in the winnower. A pressure buildup can cause undesirable winnowing inefficiencies by increasing turbulence in the separation chamber 323. In an embodiment, an exhaust screen or exhaust bag can be made of a breathable material that can permit air to pass through it (e.g., a mesh or loose cloth material).

Figure 8 illustrates an embodiment of a grinder 400. The grinder 400 can optionally be used to grind grain, such as after the grain is separated from chaff using the winnower 300. Any of a variety of grinders known to those skilled in the art can be used, including but not limited to manual grinders such as a mortar and pestle, or mechanical grinders, such as can be human-powered or otherwise automated or motorized, such as using an electrical or gas- powered motor. By way of illustration, a non-limiting example of a manual grinder 400 is shown in Figures 8 and 9.

In the embodiment of Figures 8 and 9, the grinder 400 comprises a housing 410 including a hopper 412, a front plate 414, a rear plate 416, and a cover plate 418. The grinder of Figures 8 and 9 has a helical shaft 420 disposed through the housing, from the front plate 414, across the hopper 412, and through the rear plate 416 and the cover plate 418. An end of the shaft 420 extends through and out of the cover plate 418, and can be rotatably secured by a first clamp 422. An opposite end of the shaft 420 extends out of the front plate 414, and can be rotatably secured in position with a second clamp 424. A crank arm 426 is attached to the shaft 420. The crank arm 426 can be coupled to a crank handle 428. As shown in Figure 9, the grinder 400 includes one or more adjustable burrs 430. The burrs are configured to receive grain and grind the grain into smaller pieces of various sizes. The spacing between the one or more adjustable burrs 430 can be adjusted to provide a coarsely or finely ground final product, i.e., a meal or powder.

In an embodiment of a grain processing system 100 of the invention, the system is comprised of two or more grain processing components may be mounted to a work table or work station or other support structure. For example, two or more of the stripper 110, the thresher 200, and the winnower 300 can be secured to a work table. Grain removed from a grain panicle, such as removed using the stripper 110, can be collected and removed, for further processing at a later time or at a separate grain processing station. In an embodiment, the stripper 110, the thresher 200 and the winnower 300, with or without the grinder 400, can be co-located and secured to the same work area; and they may be configured or additionally equipped so that material being processed moves along processing paths 10 with minimal handling by operators. Further, in some embodiments, the system can be configured with multiple pulleys and/or gear assemblies, such as to enable rotation of multiple crank arms. In yet other embodiments, the system 100 can be configured such that a single crank arm drives the thresher crank shaft 208 and the stripper crank shaft 113. That is, when a single operator turns the stripper crank arm 112, the grain stripper 110 and the thresher 200 can be concurrently operated. These and other configuration alternatives can improve system usability by enabling a single operator to concurrently operate multiple components of a grain processing system 100. In some embodiments, crank arms of the various system components can be driven by other means, such as by a motor or a pulley system driven by a bicycle.

Various modifications, adaptations and alterations of this invention will be apparent to those skilled in the art without departing from the scope and spirit of this invention. It should be understood that this invention is not to be unduly limited to the illustrative embodiments set forth herein.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A grain processing system, comprising a stripper, a thresher, and a winnower.

2. The system of claim 1, wherein:

the stripper comprises a roller assembly, the roller assembly comprising a first roller having a first longitudinal axis and a second roller having a second longitudinal axis, the first and second longitudinal axes are substantially parallel, and the second roller is spaced apart from the first roller to form a longitudinal gap therebetween; a stripper crank arm coupled to at least one of the first roller or the second roller; and a front plate including an in-feed hole; and the front plate being disposed near the first and second rollers such that the in-feed hole is aligned with the longitudinal gap between the first and second rollers and an axis of the front plate being substantially parallel to the first and second longitudinal axes;

the thresher comprises a thresher hopper and a threshing assembly, the thresher hopper being coupled to the threshing assembly and configured to feed contents of the thresher hopper into the threshing assembly; and the threshing assembly comprising a wheel assembly, a thresher crank arm coupled to the wheel assembly, a paddle coupled to the wheel assembly, and a perforated screen; and the paddle being oriented at an angle relative to the perforated screen; and

the winnower comprises a feeder, an aspirator, and a separator; and

wherein the feeder is coupled to the separator; the feeder is configured to introduce a grain mixture into the separator; the aspirator is coupled to an end portion of the separator; and the aspirator is configured to introduce an airflow into the separator.

3. The system of claim 1, wherein the stripper comprises a roller assembly, the roller assembly comprising a first roller having a first longitudinal axis and a second roller having a second longitudinal axis, the first and second longitudinal axes are substantially parallel, and the second roller is spaced apart from the first roller to form a longitudinal gap therebetween; a stripper crank arm, coupled to at least one of the first roller or the second roller; and a front plate including an in- feed hole; and wherein the front plate is disposed near the first and second rollers such that the in-feed hole is aligned with the longitudinal gap between the first and second rollers and an axis of the front plate is substantially parallel to the first and second longitudinal axes.

4. The system of claim 1, wherein the thresher comprises a thresher hopper and a threshing assembly, the thresher hopper being coupled to the threshing assembly and configured to feed contents of the thresher hopper into the threshing assembly; and the threshing assembly comprises a wheel assembly, a thresher crank arm coupled to the wheel assembly, a paddle coupled to the wheel assembly, a perforated screen; and the paddle is oriented at an angle relative to the perforated screen.

5. The system of claim 1, wherein the winnower comprises a feeder, an aspirator, and a separator; and wherein the feeder is coupled to the separator, the feeder is configured to introduce a grain mixture into the separator; the aspirator is coupled to an end portion of the separator ;and the aspirator is configured to introduce an airflow into the separator.

6. The system of any one of claims 2 and 3, wherein the stripper crank arm is configured to rotatably drive at least one of the first roller or second roller.

7. The system of any one of claims 2, 3 and 6, wherein the threshing assembly further comprises a stripper handle that is coupled to the stripper crank arm, and the stripper crank arm is configured to rotatably drive the first roller in response to a manual cranking motion applied to the stripper handle.

8. The system of any one of claims 2, 3, 6 and 7, wherein the front plate includes an in- feed hole that is sized to receive a grain panicle.

9. The system of any one of claims 2, 3 and 6 to 8, wherein the front plate includes multiple in- feed holes that are aligned with the longitudinal gap between the first and second rollers.

10. The system of claim 9, wherein the multiple in-feed holes have different diameters.

11. The system of any one of claims 2, 3 and 6 to 10, wherein the roller assembly and the front plate are fixedly coupled together.

12. The system of any one of claims 2, 3 and 6 to 11, wherein the stripper further comprises a housing that is configured to at least partially surround the roller assembly.

13. The system of any one of claims 2, 3 and 6 to 12, wherein the stripper further comprises a shield assembly configured to substantially surround the front plate.

14. The system of claim 13, wherein the shield assembly is configured to direct material stripped from a grain panicle toward a catch basin.

15. The system of any one of claims 2 to 14, wherein the paddle includes an angled portion that approaches and tapers toward the perforated screen.

16. The system of any one of claims 2 to 15, wherein the threshing assembly includes two or more paddles coupled to the wheel assembly, and each of the paddles includes an angled portion that approaches and tapers toward the perforated screen.

17. The system of any one of claims 15 and 16, wherein the paddle exerts a force against the perforated screen.

18. The system of any one of claims 2 to 17, wherein the paddle includes a ridged portion on a side of the paddle that faces the perforated screen.

19. The system of claim 18, wherein the ridged portion of the paddle includes multiple ridges that are sized to accept individual pearl millet grains substantially between the ridges.

20. The system of any one of claims 2 to 19, wherein the wheel assembly is rotatably driven in response to a cranking motion applied at the thresher crank arm.

21. The system of any one of claims 2 to 20, wherein the wheel assembly further comprises a thresher handle that is coupled to the thresher crank arm, and the wheel assembly is configured to be rotatably driven in response to a manual cranking motion applied to the handle.

22. The system of any one of claims 2 to 21, further comprising a thresher assembly housing to contain the threshing assembly, wherein the thresher assembly housing is at least partially open along a bottom portion, and the perforated screen is disposed at least partially over the bottom portion.

23. The system of any one of claims 2 to 22, wherein the thresher has a plurality of paddles and at least one paddle is a compliant paddle assembly.

24. The system of any one of claims 2 to 23, further comprising a winnower crank arm coupled to the feeder and configured to mechanically drive the feeder.

25. The system of any one of claims 2 to 23, further comprising a winnower crank arm coupled to the aspirator and configured to mechanically drive the aspirator.

26. The system of any one of claims 2 to 23, further comprising a winnower crank arm coupled to the feeder and the aspirator, wherein the crank arm mechanically drives the feeder and the aspirator such that a rate of operation of the feeder is different than a rate of operation of the aspirator.

27. The system of any one of claims 2 to 26, wherein at least a portion of the feeder is transparent.

28. The system of any one of claims 2 to 27, wherein at least a portion of the separator is transparent.

29. The system of any one of claims 2 to 28, wherein the feeder further comprises: a winnower hopper; and an auger conveyer configured to direct the grain mixture from the winnower hopper to the separator.

30. The system of any one of claims 2 to 29, further comprising a coupling between the aspirator and the separator includes a venturi to reduce turbulence of an airflow in the separator.

31. The system of any one of claims 2 to 30, further comprising a coupling between the feeder and the separator includes an overhang portion that facilitates distribution of the grain mixture into the separator and inhibits air in the separator from entering the feeder.

32. The system of any one of claims 1 to 31, further comprising a grinder portion configured to grind the grain separated using the winnower portion.

33. A grain processing method, comprising the steps of:

receiving an end portion of an unprocessed grain panicle, via an in-feed hole of a stripper, in a gap between a pair of rollers;

rotating at least one of the rollers to draw the unprocessed grain panicle through the in-feed hole;

separating a grain mixture from a stalk portion of the unprocessed grain panicle;

receiving the grain mixture in a thresher hopper of a thresher;

receiving the grain mixture in a threshing assembly via the thresher hopper;

pressing the grain mixture against a first side of a perforated screen using an angled paddle inside of the threshing assembly;

passing the grain mixture between the perforated screen and the angled paddle inside of the threshing assembly;

receiving a seed portion of the grain mixture on a second side of the perforated screen, wherein the second side is opposite the first side of the perforated screen;

receiving the seed portion in a feeder of a winnower;

introducing the seed portion into a separator of the winnower using the feeder; and providing an airflow from an aspirator of the winnower into the separator, wherein the airflow is introduced at a rate sufficient to expel a chaff portion of the seed portion from the winnower.

34. The method of claim 33, further comprising the step of providing the grain processing system of any of claims 2 to 31 prior to the step of receiving an end portion of an

unprocessed grain panicle.

35. A thresher, comprising: a thresher hopper; and a threshing assembly, the thresher hopper coupled to the threshing assembly and configured to feed contents of the thresher hopper into the threshing assembly; wherein the threshing assembly comprises: a wheel assembly; a thresher crank arm coupled to the wheel assembly; a paddle coupled to the wheel assembly; and a perforated screen; and the paddle is oriented at an angle relative to the perforated screen.

36. The thresher of claim 35, wherein the paddle includes an angled portion that approaches and tapers toward the perforated screen.

37. The thresher of claim 36, wherein the grain threshing assembly includes two or more paddles coupled to the wheel assembly, and each of the paddles includes an angled portion that approaches and tapers toward the perforated screen.

38. The thresher of claim 35, wherein the paddle exerts a force against the perforated screen.

39. The thresher of claim 35, wherein the paddle includes a ridged portion on a side of the paddle that faces the perforated screen.

40. The thresher of claim 37, wherein the ridged portion of the paddle includes multiple ridges that are sized to accept individual pearl millet grains substantially between the ridges.

41. The thresher of claim 35, wherein the wheel assembly is rotatably driven in response to a cranking motion applied at the thresher crank arm.

42. The thresher of claim 41, further comprising a thresher handle that is coupled to the thresher crank arm; and wherein the wheel assembly is configured to be rotatably driven in response to a manual cranking motion applied to the handle.

43. The thresher of any one of claims 35 to 42, further comprising a thresher assembly housing to contain the threshing assembly, wherein the thresher assembly housing is at least partially open along a bottom portion, and the perforated screen is disposed at least partially over the bottom portion.

44. The thresher of claim 35, having a plurality of paddles coupled to the wheel assembly and wherein the at least one of the plurality of paddles is a compliant paddle assembly.

45. A grain threshing method, comprising the steps of:

receiving a grain mixture in a thresher hopper;

receiving the grain mixture in a threshing assembly via the thresher hopper;

passing the grain mixture between the perforated screen and the angled paddle inside of the threshing assembly; and

receiving a seed portion of the grain mixture on a second side of the perforated screen, wherein the second side is opposite the first side of the perforated screen.

46. The method of claim 45, further comprising the step of providing the thresher of any one of claims 35 to 44 prior to the step of receiving a grain mixture in a thresher hopper.

47. A winnower, comprising: a feeder; an aspirator; and a separator;

wherein the feeder is coupled to the separator, the feeder is configured to introduce a grain mixture into the separator, the aspirator is coupled to an end portion of the separator, and the aspirator is configured to introduce an airflow into the separator.

48. The winnower of claim 47, further comprising a winnower crank arm coupled to the feeder and configured to mechanically drive the feeder.

49. The winnower of claim 47, further comprising a winnower crank arm coupled to the aspirator and configured to mechanically drive the aspirator.

50. The winnower of claim 47, further comprising a winnower crank arm coupled to the feeder and the aspirator, wherein the crank arm mechanically drives the feeder and the aspirator such that a rate of operation of the feeder is different than a rate of operation of the aspirator.

51. The winnower of any one of claims 47 to 50, wherein at least a portion of the feeder is transparent.

52. The winnower of any one of claims 47 to 51 , wherein at least a portion of the separator is transparent.

53. The winnower of any one of claims 47 to 52, wherein the feeder further comprises: a winnower hopper; and an auger conveyer configured to direct the grain mixture from the winnower hopper to the separator.

54. The winnower of any one of claims 47 to 53, further comprising an aspirator coupling between the aspirator and the separator, the aspirator coupling including a venturi to reduce turbulence of an airflow in the separator.

55. The winnower of any one of claims 47 to 53, further comprising a feeder coupling between the feeder and the separator, the feeder coupling including an overhang portion that facilitates distribution of the grain mixture into the separator and inhibits air in the separator from entering the feeder.

56. A winnower method, comprising the steps of:

receiving a mixture of grain and chaff in a feeder of a winnower;

introducing the mixture into a separator of the winnower using the feeder; and providing an airflow from an aspirator of the winnower into the separator; wherein the airflow is introduced at a rate sufficient to expel a chaff portion of the mixture from the winnower.

57. The method of claim 56, further comprising the step of providing the winnower of any one of claims 47 to 55 prior to the step of receiving a mixture of grain and chaff in a feeder of a winnower.

58. A grain stripper, comprising:

a roller assembly, the roller assembly comprising a first roller having a first longitudinal axis and a second roller having a second longitudinal axis, the first and second longitudinal axes are substantially parallel, and the second roller is spaced apart from the first roller to form a longitudinal gap therebetween;

a stripper crank arm, coupled to at least one of the first roller or the second roller; and a front plate including an in- feed hole;

wherein the front plate is disposed near the first and second rollers such that the in- feed hole is aligned with the longitudinal gap between the first and second rollers and wherein an axis of the front plate is substantially parallel to the first and second longitudinal axes.

59. The stripper of claim 58, wherein the stripper crank arm is configured to rotatably drive at least one of the first roller or second roller.

60. The stripper of claim 58, further comprising a stripper handle that is coupled to the stripper crank arm, wherein the stripper crank arm is configured to rotatably drive the first roller in response to a manual cranking motion applied to the handle.

61. The stripper of any one of claims 58 to 60, wherein the front plate includes an in-feed hole that is sized to receive a grain panicle.

62. The stripper of any one of claims 58 to 60, wherein the front plate includes multiple in- feed holes that are aligned with the longitudinal gap between the first and second rollers.

63. The stripper of claim 62, wherein the multiple in- feed holes have different diameters.

64. The stripper of any one of claims 58 to 63, wherein the roller assembly and the front plate are fixedly coupled together.

65. The stripper of any one of claims 58 to 64, further comprising a housing that is configured to at least partially surround the roller assembly.

66. The stripper of any one of claims 58 to 65, further comprising a shield assembly configured to substantially surround the front plate.

67. The stripper of claim 67, wherein the shield assembly is configured to direct material stripped from a grain panicle toward a catch basin.

68. A grain stripping method, comprising the steps of:

receiving an end portion of an unprocessed grain panicle, via an in-feed hole of a grain stripper, in a gap between a pair of rollers;

rotating at least one of the rollers to draw the unprocessed grain panicle through the in-feed hole; and

separating a grain portion from a stalk portion of the unprocessed grain panicle.

69. The method of claim 67, further comprising the step of providing the stripper of any one of claims 58 to 67 prior to the step of receiving an end portion of an unprocessed grain panicle.