Abstract:
A combine having a mobile frame and a harvesting header for removing crop material from the field and feeding it to a central location. A threshing and separating system separates grain from crop material and a feeder housing receives crop material from the harvesting head and conveys it to the threshing and separating system. A grain tank has a conveyor for transferring separated grain to the grain tank. Either of the harvesting header or the feeder housing has a perforated floor section sufficiently coarse to permit passage of grain to a conveyor beneath the perforated floor section that receives the grain and delivers it to either downstream of the threshing and separating system or the separated grain conveyor.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to agricultural combines, and, more specifically to grain extraction in such machines. 
         [0003]    2. Description of the Related Art 
         [0004]    Combines are used to harvest agricultural crops such as corn, soybeans, wheat and other grain crops. As the combine is driven through crop fields, the combine cuts the crop, separates the desired crop from the undesired waste, also known as material other than grain (MOG), stores the crop and discards the waste. 
         [0005]    In a typical combine, a header is mounted to the front of the combine to gather the crop and feed the crop into the combine for processing. As the combine is driven through the field, the crop material is collected by the header and deposited into a feeder housing. The material is then transported upwardly and into the combine by a feed elevator located within the feeder housing. The crop material then passes through a threshing and separating system. In a rotary combine, the threshing and separating system usually includes a rotor, a threshing concave, a rotor cage and a separating grate. As crop material passes between the rotor, the threshing concave and the separating gate, the crop material is impacted and/or rubbed thereby causing the grain to separate from the stalk material. The stalk material that is separated from the grain is commonly referred to as MOG. Other types of combines are known that perform similar functions using different mechanisms. 
         [0006]    After passing through the threshing and separating system, the grain and MOG are deposited onto a grain cleaning system. The grain cleaning system of the typical combine includes a plurality of adjustable cleaning sieves often referred to as a chaffer sieve and a shoe sieve and sometimes a pre-cleaning sieve. These sieves are typically reciprocated back and forth in opposite directions along an arcuate path. This motion has the tendency to separate the grain from the MOG. To further separate the grain from the MOG, a cleaning fan or blower is positioned so as to blow air up through the cleaning sieves. This flow of air tends to blow the MOG, which is typically lighter than grain, rearwardly and out the back of the combine. Grain which is heavier than MOG is allowed to drop through the openings in the sieve. 
         [0007]    The clean grain that falls through the cleaning sieves is deposited on a collection panel positioned between the cleaning sieves. The collection panel is angled so as to promote the grain to flow, under the influence of gravity, onto a conveyor such as an auger trough positioned along the lower most edge of the collection panel. The auger trough is typically positioned near the forward end of the cleaning sieves and extends along the width of the sieves. The grain collected in the auger trough is then moved by an auger towards the side of the combine where it is raised by a grain elevator and deposited into a storage tank or grain tank. Other systems also exist that can utilize for example, a loop conveyor system which eliminates the need for a conventional cross auger. 
         [0008]    With the progression in the technology of the agricultural field, combines are being called on to be ever more efficient in the extraction of grain and the processing capacity for a given size. As the quantity of grain and MOG delivered to the threshing and separating system increases per unit of time, there is the tendency to locally exceed the capacity of the unit. It has been proposed, in an attempt to make the processing more efficient, to move some of the separating functions into the feeder housing and even the header for the combine. While these approaches have had some limited success, they do so at the expense of added complexity, cost and weight to the agricultural combine. 
         [0009]    What is needed in the art therefore is a more efficient extraction of grain within an agricultural combine. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention seeks to extract grain from the harvested material in a combine upstream of a threshing and separating function. 
         [0011]    In one form, the invention is a combine including a mobile frame having a power unit and a harvesting header mounted on the mobile frame for removing crop material from the field and feeding it to a central location. A threshing and separating system is mounted on the mobile frame for separating grain from the crop material and a feeder housing is mounted on the frame for receiving crop material from the harvesting header and conveying it to the threshing and separating system. A grain tank is mounted on the mobile frame and a conveyor transfers separated grain to the grain tank. One of the harvesting header and the feeder housing has a perforated floor section with perforations open sufficiently to pass grain therethrough. A grain collection housing and conveyor are positioned beneath the perforated floor section to receive grain and deliver it to one of downstream of the threshing and separating system and the separated grain conveyor. 
         [0012]    One benefit of the invention is a simplified configuration for separating grain from harvested crop material. 
         [0013]    Another benefit is a simplified mechanism for such separation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0015]      FIG. 1  is a side view of an embodiment of a combine with which the present invention may be utilized; 
           [0016]      FIG. 2  is a cross-sectional view of a grain cleaning system that may be used with the combine of  FIG. 1 ; 
           [0017]      FIG. 3  is a partial side view of the combine of  FIG. 1  showing one early grain extraction device; 
           [0018]      FIG. 4  is a perspective view of the combine of  FIG. 3 ; 
           [0019]      FIG. 5  is a side view of a header incorporating another early grain extraction device; 
           [0020]      FIG. 6  is still another arrangement of an early grain extraction device applied to a combine header; 
           [0021]      FIG. 7  is a side view of the header shown in  FIG. 5 ; and 
           [0022]      FIG. 8  is a perspective view of an alternate arrangement to  FIG. 4 . 
       
    
    
       [0023]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    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. 
         [0025]    Referring now to the drawings, and more particularly to  FIG. 1 , there is shown an agricultural harvester in the form of a combine  10 , which generally includes a mobile frame  12 , ground engaging wheels  14  and  16 , a header  18 , a feeder housing  20 , an operator cab  22 , a threshing and separating system  24 , a grain cleaning system  26 , a grain tank  28 , and an unloading auger  30 . It should be appreciated that while the agricultural harvester is shown as combine  10 , the agricultural harvester according to the present invention can be any type of construction that allows for crop material to be harvested such as a conventional combine (which does not have a rotor), rotary combine, hybrid combine, chopper harvester, etc. 
         [0026]    Front wheels  14  are larger flotation type wheels, and rear wheels  16  are smaller steerable wheels. Motive force is selectively applied to front wheels  14  through a power plant in the form of a diesel engine  32  and a transmission (not shown). Although combine  10  is shown as including wheels, is also to be understood that combine  10  may include tracks, such as full tracks or halftracks. 
         [0027]    Header  18  is mounted to the front of combine  10  and includes a cutter bar  34  for severing crops from a field during forward motion of combine  10 . A rotatable reel  36  feeds the crop into header  18 , and a double auger  38  feeds the severed crop laterally inwardly from each side toward feeder housing  20 . Feeder housing  20  conveys the cut crop to threshing and separating system  24 , and is selectively vertically movable using appropriate actuators, such as hydraulic cylinders (not shown). 
         [0028]    Threshing and separating system  24  is of the axial-flow type, and generally includes a rotor  40  at least partially enclosed by and rotatable within a corresponding perforated concave  42 . The cut crops are threshed and separated by the rotation of rotor  40  within concave  42 , and larger elements, such as stalks, leaves and the like are discharged from the rear of combine  10 . 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 concave  42 . 
         [0029]    Grain which has been separated by the rotor  40  and perforated concaves  42  falls onto a main grain pan  44  and is conveyed toward grain cleaning system  26 . Grain cleaning system  26  may include an optional pre-cleaning sieve  46 , an upper sieve  48  (also known as a chaffer sieve), a lower sieve  50  (also known as a shoe sieve), and a cleaning fan  52 . Grain on sieves  46 ,  48  and  50  is subjected to a cleaning action by fan  52  which provides an airflow through the sieves to remove chaff and other impurities such as dust from the grain by making this material airborne for discharge from straw hood  54  of combine  10 . Main grain pan  44  and pre-cleaning sieve  46  oscillate or reciprocate in a fore-to-aft manner to transport the grain and finer non-grain crop material to the upper surface of upper sieve  48 . Upper sieve  48  and lower sieve  50  are vertically arranged relative to each other, and likewise oscillate in a fore-to-aft manner to spread the grain across sieves  48 ,  50 , while permitting the passage of cleaned grain by gravity through the openings of sieves  48 ,  50 . 
         [0030]    Clean grain falls to a clean grain auger  56  positioned crosswise below and in front of lower sieve  50 . Clean grain auger  56  receives clean grain from each sieve  48 ,  50  and from bottom pan  58  of grain cleaning system  26 . Clean grain auger  56  conveys the clean grain laterally to a generally vertically arranged elevator  60 , which can also be referred to as a grain elevator, for transport to grain tank  28 . Tailings from grain cleaning system  26  fall to a tailings auger on  62 . The tailings are transported via tailings auger  64  and return auger  66  to the upstream end of grain cleaning system  26  for repeated cleaning action. A pair of grain tank augers  68  at the bottom of grain tank  28  convey the clean grain laterally within grain tank  28  to unloading auger  30  for discharge from combine  10 . The non-grain crop material proceeds through a residue handling system  70 . Residue handling system  70  may include a chopper, counter knives, a windrow door and a residue spreader. 
         [0031]    Referring now to  FIG. 2 , a grain cleaning system  26 , is shown in cross-section. Prior to the grain cleaning system  26 , the rotor  40  and perforated concave  42  (not shown in  FIG. 2 ) operates to create a mat of the crop material and pass it through a narrow gap between the rotor  40  and the perforated concave  42  to thresh or separate the grains from the larger elements of MOG such as stems, stalks, leaves, pods, and plant fragments, such that a flow of the grain will be discharged into the grain cleaning system  26 . This flow of grain will include some smaller elements of MOG, and falls on main grain pan  44 . A reciprocating motion causes the mixture of grain and residual MOG to move rearwardly until it passes over a fall step  100 . The mixture then falls on the pre-cleaning sieve  46 , where a certain volume of the mixture of grain and residual MOG are separated, again under reciprocal motion of the pre-cleaning sieve. Excess volume of the mixture of grain and residual MOG passes over the pre-cleaning sieve  46  onto the upper or chaffer sieve  48 . The grain cleaned by pre-cleaning sieve  46  and upper sieve  48  then falls through to lower or shoe sieve  50  for further cleaning, also under reciprocal motion. Because the pre-cleaning sieve  46  does not line up perfectly vertically with lower sieve  50 , a grain transfer pan  72  reciprocally moves the partially cleaned grain rearwardly to fall onto the lower sieve  50 . 
         [0032]    Throughout this movement of the mixture of grain and residual MOG, a cleaning fan  52  blows air up past the ends of the main grain pan  44  and the grain transfer pan  72 , and up through the pre-cleaning sieve  46 , the upper sieve  48 , and the lower sieve  50 , by way of fan main outlet  122  leading to fan upper outlet  106  and fan lower outlet  110 , guided by fan outlet air guide  112 . Air enters the cleaning fan  52  at fan inlet  120  and is accelerated radially and tangentially, further guided by fan wrapper  114 . Fan inlet  120  is partly defined by the terminus of fan wrapper  114 , which is referred to as wrapper cut-off point  118 , and by the terminus of fan outlet air guide  112 , which is referred to as vortex cut-off point  116 . In this way, the mixture of grain and residual MOG is suspended and separated as it passes through grain cleaning system  26 . Some MOG is blown rearward toward the residue handling system  70  (not shown) as it passes over fall step  100 . Clean grain falls through pre-cleaning sieve  46 , upper sieve  48 , and lower sieve  50  onto bottom pan  58  and descends into the clean grain auger  56 , while additional MOG separated by the pre-cleaning sieve  46 , the upper sieve  48 , and the lower sieve  50  again blows rearward towards the residue handling system  70 . Some grain and residual MOG that is difficult to separate passes over the pre-cleaning sieve  46 , the upper sieve  48 , and the lower sieve  50  and falls onto the tailings auger trough  62 . These difficult to separate portions, called tailings, then descend into the tailings auger  64 , where they are sent back through the threshing and separating system  24  by the return auger  66  (not shown). 
         [0033]    In accordance with the present invention an early grain extraction device is illustrated in different forms in  FIGS. 3, 5 and 6 . Referring particularly to  FIG. 3  which shows a partial section view of the combine of  FIG. 1 , a grain collection housing  124  is positioned underneath the feeder housing  20  which has a perforated floor section  126  permitting passage of grain that has already been thrashed or separated into grain collection housing  124 . The openings in perforated floor section  126  are selected to be large enough to pass the grain for the particular crop selected. The grain collection housing  124  extends from the forward section of feeder housing  20  to its aft end. Within the grain collection housing  124 , an upper sieve  130  and lower sieve  132  are positioned to reciprocate and to move grain from the forward end of feeder housing  20  to its aft end. A blower  134  discharges air through the gap between upper sieve and lower sieve  130  and  132  to blow any tailings and chaff to and through a duct  140  past a flexible section  142  and through duct  144  to the duct  144  to the grain pan  44  to be acted on by the grain cleaning system  26 . Grain collection housing  124  has a laterally extending auger trough  136  which contains an auger  138  extending across grain collection housing  124  for collection of the grain that has passed into auger trough  136 . 
         [0034]    As shown in  FIG. 4 , the auger  138  discharges the grain to a pneumatic or mechanical conveyance device  146  which delivers it to a duct  48  leading to outlet  150  that deposits it in the cleaning system  26  of the combine  10 . It should be noted that the pneumatic or mechanical conveyance device  146  may be an auger or a blower. In similar manner the sieve elements  130  and  132  may be conveyors delivering the material that has passed through the perforated floor section  126  to the aft end of grain collection housing  124 . 
         [0035]    The provision of the perforated floor section  126  allows early extraction of grain to be handled in a parallel fashion to the threshing and separating system  24 . As a result, the capacity of the threshing and separating system  24  can be increased since it is not required to handle 100% of the crop material passing into the feeder housing  20 . In like fashion, the tailings and chaff that have passed through floor section  126 , also bypasses the threshing and separating system  24  to enable a further increase in capacity. 
         [0036]    The arrangement shown in  FIGS. 3 and 4  illustrate application of early grain to the feeder housing  20 . The arrangements illustrated in  FIGS. 5 and 6  show the application of this technique to the header  18 . Referring particularly to  FIG. 5 , header  18  has an auger  38  passing crop to the center and a grain collection housing  152  is positioned along and underneath auger  38  and has an auger trough  154  and auger  156  to move grain that falls through a perforated floor section  158  to one side of the header  18 . As shown in  FIG. 7 , a conveyance device  160  receives grain from auger  172  and directs it through duct  162  to the cleaning system  26  of combine  10 . As stated above, the conveyance device  160  may be pneumatic or mechanical. In this instance the early grain separation occurs even before the feeder housing  20 . 
         [0037]    Referring now to  FIG. 6 , the device is shown in connection with a corn head  164  that may be fitted to the combine  10 . The harvested corn is transferred laterally in the corn head to the center by auger  166  and a grain collection housing  166  is fitted underneath and along auger  166 . A perforated floor section  168  allows grain to pass there through into grain collection housing  166 . An auger trough  170  is formed in the bottom of grain collection housing  166  and an auger  172  passes the grain to one side of the corn head for delivery to the grain cleaning system as illustrated in  FIG. 7 . 
         [0038]    An alternative to the delivery of early extracted grain to the cleaning system is shown in  FIG. 8  in which the auger  138  in the feeder housing  20  connects to a conveyance device  146  connecting to a duct  174  leading to the grain elevator  160 . This may be used when the grain thus collected is particularly clean and free of debris. 
         [0039]    In all of the embodiments set forth and described above, the early extraction of grain is provided simply by a perforated floor section leading to a chamber and conveying devices within the chamber to move the grain to the appropriate system within the combine. The design has the benefit of a minimum of extra complexity and cost and allows a parallel path for grain to permit greater capacity in the threshing and separating system  24  of the combine  10 . 
         [0040]    While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.