Sieve arrangements for a cleaning system in an agricultural harvester

A cleaning system for an agricultural combine harvester includes a sieve having a periphery and an interference member located at the periphery. A chaffer frame carries the sieve, and includes a clamp with a pair of spring fingers positioned on either side of the interference member, thereby retaining the sieve within the chaffer frame.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a non-provisional application based upon U.S. provisional patent application Ser. No. 62/196,071, entitled “SIEVE ARRANGEMENTS FOR A CLEANING SYSTEM IN AN AGRICULTURAL HARVESTER”, filed Jul. 23, 2015, which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to agricultural harvesters such as combines, and, more particularly, to cleaning systems used in such combines.

2. Description of the Related Art

An agricultural harvester known as a “combine” is historically termed such because it combines multiple harvesting functions with a single harvesting unit, such as picking, threshing, separating and cleaning. A combine includes a header which removes the crop from a field, and a feeder housing which transports the crop matter into a threshing rotor. The threshing rotor rotates within a perforated housing, which may be in the form of adjustable concaves, and performs a threshing operation on the crop to remove the grain. Once the grain is threshed it falls through perforations in the concaves onto a grain pan. From the grain pan the grain is cleaned using a cleaning system, and is then transported to a grain tank onboard the combine. The cleaning system includes a cleaning fan which blows air through oscillating sieves to discharge chaff and other debris toward the rear of the combine. Non-grain crop material such as straw from the threshing section proceeds through a straw chopper and out the rear of the combine. When the grain tank becomes full, the combine is positioned adjacent a vehicle into which the grain is to be unloaded, such as a semi-trailer, gravity box, straight truck, or the like; and an unloading system on the combine is actuated to transfer the grain into the vehicle.

More particularly, a rotary threshing or separating system includes one or more rotors which can extend axially (front to rear) or transversely within the body of the combine, and which are partially or fully surrounded by a perforated concave. The crop material is threshed and separated by the rotation of the rotor within the concave. Coarser non-grain crop material such as stalks and leaves are transported to the rear of the combine and discharged back to the field. The separated grain, together with some finer non-grain crop material such as chaff, dust, straw, and other crop residue are discharged through the concaves and fall onto the grain pan where they are transported to the cleaning system. Alternatively, the grain and finer non-grain crop material may also fall directly onto the cleaning system itself.

The cleaning system further separates the grain from non-grain crop material, and typically includes a fan directing an air flow stream upwardly and rearwardly through vertically arranged sieves which oscillate in a fore and aft manner. The air flow stream lifts and carries the lighter non-grain crop material towards the rear end of the combine for discharge to the field. Clean grain, being heavier, and larger pieces of non-grain crop material, which are not carried away by the air flow stream, fall onto a surface of an upper sieve (also known as a chaffer sieve) where some or all of the clean grain passes through to a lower sieve (also known as a cleaning sieve). Grain and non-grain crop material remaining on the upper and lower sieves are physically separated by the reciprocating action of the sieves as the material moves rearwardly. Any grain and/or non-grain crop material remaining on the top surface of the upper sieve are discharged at the rear of the combine. Grain falling through the lower sieve lands on a bottom pan of the cleaning system, where it is conveyed forwardly toward a clean grain auger.

The cleaning system can include a sieve which is mounted within a chaffer frame, and the chaffer frame is oscillated in a fore-to-aft direction to clean the grain. The sieve can be removable from the chaffer frame for cleaning and repair, but removal of the sieve can be difficult.

What is needed in the art is a cleaning system with a sieve which can be more easily removed from and installed within a chaffer frame, and securely held in place during oscillations of the chaffer frame.

SUMMARY OF THE INVENTION

The present invention provides a cleaning system with a chaffer frame having a clamp, and a sieve with an interference member which interacts with the clamp to guide the sieve into place within the chaffer frame, and hold the sieve within the chaffer frame.

The invention in one form is directed to a cleaning system for an agricultural combine harvester, including a sieve having a periphery and an interference member located at the periphery. A chaffer frame carries the sieve, and includes a clamp with a pair of spring fingers positioned on either side of the interference member, thereby retaining the sieve within the chaffer frame.

The invention in another form is directed to an agricultural combine harvester, including a chassis and a cleaning system carried by the chassis. The cleaning system includes a sieve having a periphery and an interference member located at the periphery. A chaffer frame carries the sieve, and includes a clamp with a pair of spring fingers positioned on either side of the interference member, thereby retaining the sieve within the chaffer frame.

DETAILED DESCRIPTION OF THE INVENTION

The terms “grain”, “straw” and “tailings” are used principally throughout this specification for convenience but it is to be understood that these terms are not intended to be limiting. Thus “grain” refers to that part of the crop material which is threshed and separated from the discardable part of the crop material, which is referred to as non-grain crop material, MOG or straw. Incompletely threshed crop material is referred to as “tailings”. Also the terms “forward”, “rearward”, “left” and “right”, when used in connection with the agricultural harvester and/or components thereof are usually determined with reference to the direction of forward operative travel of the harvester, but again, they should not be construed as limiting. The terms “longitudinal” and “transverse” are determined with reference to the fore-and-aft direction of the agricultural harvester and are equally not to be construed as limiting.

Referring now to the drawings, and more particularly toFIG. 1, there is shown an agricultural harvester in the form of a combine10, which generally includes a chassis12, ground engaging wheels14and16, header18, feeder housing20, operator cab22, threshing and separating system24, cleaning system26, grain tank28, and unloading auger30.

Front wheels14are larger flotation type wheels, and rear wheels16are smaller steerable wheels. Motive force is selectively applied to front wheels14through a power plant in the form of a diesel engine32and a transmission (not shown). Although combine10is shown as including wheels, is also to be understood that combine10may include tracks, such as full tracks or half tracks.

Header18is mounted to the front of combine10and includes a cutter bar34for severing crops from a field during forward motion of combine10. A rotatable reel36feeds the crop into header18, and a double auger38feeds the severed crop laterally inwardly from each side toward feeder housing20. Feeder housing20conveys the cut crop to threshing and separating system24, and is selectively vertically movable using appropriate actuators, such as hydraulic cylinders (not shown).

Threshing and separating system24is of the axial-flow type, and generally includes a rotor40at least partially enclosed by and rotatable within a corresponding perforated concave42. The cut crops are threshed and separated by the rotation of rotor40within concave42, and larger elements, such as stalks, leaves and the like are discharged from the rear of combine10. Smaller elements of crop material including grain and non-grain crop material, including particles lighter than grain, such as chaff, dust and straw, are discharged through perforations of concave42. Threshing and separating system24can also be a different type of system, such as a system with a transverse rotor rather than an axial rotor, etc.

Grain which has been separated by the threshing and separating assembly24falls onto a grain pan44and is conveyed toward cleaning system26. Cleaning system26may include an optional pre-cleaning sieve46, an upper sieve48(also known as a chaffer sieve), a lower sieve50(also known as a cleaning sieve), and a cleaning fan52. Grain on sieves46,48and50is subjected to a cleaning action by fan52which provides an air flow through the sieves to remove chaff and other impurities such as dust from the grain by making this material airborne for discharge from straw hood54of combine10. Grain pan44and pre-cleaning sieve46oscillate in a fore-to-aft manner to transport the grain and finer non-grain crop material to the upper surface of upper sieve48. Upper sieve48and lower sieve50are vertically arranged relative to each other, and likewise oscillate in a fore-to-aft manner to spread the grain across sieves48,50, while permitting the passage of cleaned grain by gravity through the openings of sieves48,50.

Clean grain falls to a clean grain auger56positioned crosswise below and toward the front of lower sieve50. Clean grain auger56receives clean grain from each sieve48,50and from bottom pan58of cleaning system26. Clean grain auger56conveys the clean grain laterally to a generally vertically arranged grain elevator60for transport to grain tank28. Tailings from cleaning system26fall to a tailings auger trough62. The tailings are transported via tailings auger64and return auger66to the upstream end of cleaning system26for repeated cleaning action. A pair of grain tank augers68at the bottom of grain tank28convey the clean grain laterally within grain tank28to unloading auger30for discharge from combine10.

Referring now toFIGS. 2-6, there is shown an embodiment of a sieve arrangement100of the present invention, including a sieve102which can be part of the cleaning system26shown inFIG. 1, such as at a sieve location corresponding to sieves46,48and/or50.

Current sieve designs clamp the sieve at the top and bottom of the sieve, and restrain the sieve at the sides. In contrast, the sieve102of the present invention loads as a cartridge into the chaffer frame104, and rests on rails106within the chaffer frame104. Thus, there is no rigid vertical or lateral fixation of the sieve102within the chaffer frame104.

More particularly, the sieve102has a periphery108and an interference member110located at the periphery108. In the illustrated embodiment, the interference member110is in the form of a rectangular block which is mounted to and extends from a peripheral frame member112of the sieve102. In more detail, the interference member110protrudes outwardly, e.g. substantially transverse, from the surface of the peripheral frame member112of the sieve102. However, the interference member110could be differently configured, such as a disk shaped member, rod, etc.

The chaffer frame104carries the sieve102, and includes a pair of rails106upon which the sieve102rests. The sieve102can be loaded into the chaffer frame104as a cartridge. The chaffer frame104also includes a clamp116with a pair of spring fingers118positioned on either side of the interference member110, thereby retaining the sieve102within the chaffer frame104. Each spring finger118contacts onto each respective side of the interference member110, and in this regard the sieve102can be loaded into the chaffer frame104as a cartridge. The clamp116inhibits movement of the sieve102within the chaffer frame104in two axes. The spring loaded fingers118of the clamp116can also act as a guide to guide the sieve102into position within the chaffer frame104during loading. To that end, the spring fingers118can include a beveled end (not numbered, but shown, e.g., inFIG. 5) that assists in guiding the sieve into position within the chaffer frame.

Referring now toFIGS. 7-9, there is shown another embodiment of a sieve arrangement120of the present invention, including a sieve122which can be part of the cleaning system26shown inFIG. 1, such as at a sieve location corresponding to sieves46,48and/or50.

The sieve arrangement120can oscillate back and forth at 4.5 hz or higher. This subjects the sieve arrangement120, including the sieves122, to cyclical loads. Conventional sieves may not meet reliability goal with welded rear corner gussets and welded dividers due to the low allowable cyclical fatigue life of welds. In order to meet goals, allowable cyclical fatigue limits of welds would need to be approximately/−3.2 ksi or less. The allowable cyclical fatigue limit of non-welded joint is approximately/−12 ksi. By eliminating welds, the life expectancy of the sieve122is greatly improved. Since the front and rear structural members of the sieves are tubes, simply bolting the gussets and dividers creates a problem since bolting through a tube doesn't create a tight bolted joint. Also, bolts consume a large area and hinders permeable area needed for maximum cleaning of grain.

The sieves122are configured so rear corner gussets124and/or dividers126can be riveted using rivets128. Rivets128are easy to install, and take the place of welded joints to increase the reliability. Each rivet128takes the place of at least one bolt and nut and/or welded connection. The rivets128are quicker to install than bolts and nuts. Additionally, no torquing of the joint is required, as is the case if a bolted connection was used.

More particularly, the sieve122can include a plurality of peripheral frame members130, and a plurality of adjustable finger plates132mounted within the frame members130. At least two of the frame members130are interconnected with each other via a gusset124and rivets128. The peripheral frame members130can include a rear frame member130A and a pair of side frame members130B, with the rear frame member130A being attached to each of the side frame members130B via a respective gusset124and a plurality of rivets128. The peripheral frame members130can also include a front frame member130C. One or more dividers134can extend in a fore/aft direction between the front frame member130C and the rear frame member130A. Each divider134can be attached to the rear frame member130A via a respective gusset124and a plurality of rivets128.

In the illustrated embodiment, the rivets128are configured as standard rivets. However, the rivets128can also be configured as specially configured rivets, such as rivnuts.