Abstract:
An auger for a combine includes a central tube having an outer cylindrical surface and having a first diameter; flighting extends from the outer surface of the central tube. The flighting has an outer edge. An auger diameter is defined as the diameter extending from a top edge of the flighting to the bottom edge of the flighting. The first diameter is approximately 25 percent of the outer diameter.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of and claims the benefit of earlier U.S. patent application Ser. No. 09/575,509 filed May 22, 2000, now U.S. Pat. No. 6,561,896. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     FIELD OF THE INVENTION 
     This invention relates to an auger for a combine header, and, in particular, to an auger allowing longer length combine headers and lower maintenance combine headers. 
     BACKGROUND OF THE INVENTION 
     In the past, the maximum combine header length that was available was approximately 30 feet. It was found that once a header went beyond 30 feet, the auger used to convey cut crop stalks to the central portion of the header and thereafter into the separator machinery of the combine would not operate efficiently. In particular, the center auger tube of most of the combine headers in the past was at the very least approximately one third of the overall diameter of the auger. The overall diameter of the auger is the distance from the edge of the top of the flights of the augers through the center tube to the lower edge of the flights. More specifically, in a GLEANER combine header manufactured by AGCO, a header auger would have a 30-inch overall diameter. Sixteen inches of that overall diameter would be comprised of the diameter of the inner tube. Thus, the center tube of the GLEANER header would be approximately 53.3 percent of the overall diameter of the auger. In a Case International Harvester combine, with an overall auger diameter of 24 inches, the center tube would comprise approximately 14 inches of the overall diameter. Thus, in a Case International Harvester header, the center tube is approximately 58.3 percent of the overall diameter header. In a John Deere combine header having a 24-inch overall diameter, the central tube would comprise approximately sixteen inches of the overall diameter. Thus, in a John Deere combine the center tube comprised approximately 67 percent of the overall diameter. The structure of these prior art combine headers do not appear to allow the construction of combine headers beyond 30 feet. More specifically, in longer combine headers, oftentimes the crop stalks are not conveyed adequately to the central portion. In fact, some of the stalks with the heads still attached flow over the top of the auger and sometimes out of the header. Still further, oftentimes the stalks and headers are not conveyed in a continuous manner to the central portion, thus resulting in large clumps running to the central portion and being ingested into the separating cylinder portion of the combine, often resulting in “slugging” of the combine. 
     An additional disadvantage of prior art combines having long length is the maintenance associated with the retractable finger mechanisms in the very central portion of the auger. The fingers move in and out from the central portion of the combine auger tube in a retracting manner. There is a well-known mechanism within the auger tube which allows this retraction and extension. More specifically, the fingers will extend as the portion of the auger they are located on is rotated toward the bottom platform of the header. Thereafter, they will retract as they reach the farthest position away from the bottom of the header. The mechanism to accomplish this extension and retraction is rather complex and has a variety of bearings associated therewith. Additionally, the location of the retraction and extension mechanism in the center of the combine auger is often difficult to access in order to perform maintenance or repairs. 
     Therefore, a combine auger is needed which alleviates the problems with the prior art combine augers discussed above. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide a combine auger which allows increased length of combine headers. 
     Another object of the present invention is to provide a combine auger header which enhances the efficiency with which stalks and heads of crops are conveyed to the central portion of the header and fed into the separator portion of the machine. 
     A further object of the present invention is to provide a header auger for a combine which is easy to maintain and has a minimum of moving parts. 
     A still further object of the present invention is to provide a header auger for a combine which prevents carryover of crop stalks during the conveyance from the outer edges of the header to the interior portion wherein they are fed to the separator mechanism of the combine. 
     In order to accomplish the above objectives, a header auger for a combine is provided which is rotatably positioned in a combine header. The auger includes a central tube having an outer cylindrical surface and having a first diameter. The auger includes flighting extending from an outer surface of the central tube and the flighting has an outermost edge and a screw-type orientation around the central tube. An auger diameter is defined as the diameter extending from a top edge of the flighting to the bottom edge of the flighting. The first diameter of the central tube is approximately one-fourth of the overall auger diameter. 
    
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     In the accompanying drawings which form a part of this specification and are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts of the various views: 
     FIG. 1 is a front elevational view of a combine header having a header auger according to the present invention with the header auger rotatably mounted in the combine header; 
     FIG. 2 is an enlarged view of the area designated by the numeral  2  in FIG.  1  and showing the very central portion of the auger according to the present invention wherein stalks cut by the combine header are conveyed into the separator mechanism of the combine; 
     FIG. 3 is a cross-sectional view taken generally along line  3 — 3  of FIG. 2, showing the saw-toothed central portion of the combine auger according to the present invention; 
     FIG. 4 is an enlarged view of the area designated by the numeral  4  in FIG.  3  and showing the orientation and relevant angles of the saw-toothed flighting in the central portion of the auger. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to FIG. 1, a combine header generally indicated by the numeral  10  is shown incorporating the header auger  12  according to the present invention therein. As will be apparent to one of ordinary skill in the art, the combine header  10  is attached to the separator mechanism and propelling mechanism of a combine. One of ordinary skill in the art will understand the general manner in which the crops that are cut by the header are conveyed into the separating mechanisms of the combine wherein the grain is separated from the rest of the stalk and positioned in a bin, and thereafter the stalks are jettisoned from the separator mechanism back onto the field. Additionally, one of ordinary skill in the art will understand that various other structures and orientation of the header, for instance, the sickle bar  14 , and the mounting of auger  12  to header frame  16 , are well-known. 
     Turning now to the construction of auger  12 , auger  12  is comprised of a central tube  18 , a right side smooth edged flighting  20 , a left side smooth edged flighting  22 , a right sized central saw-toothed edge flighting  24 , and a left side saw-toothed edge central flighting  26 . More specifically, right side flighting  22  conveys crops cut by sickle  14  toward the center of header  10 . Thereafter, right side saw-toothed flighting  24  feeds the cut crop through an opening  28  and into then relevant separator mechanism of the combine. Likewise, left side smooth edge flighting  22  conveys cut crops from the left side of the header and toward the center, and to the left side saw-toothed flighting  26  which conveys the crop through opening  28  and into the relevant separator mechanisms of the combine. Flights  20 ,  22 ,  24  and  26  all have a helical/screw configuration to accomplish the conveying to the central portion of the header, and into the separator mechanisms of the combine. With reference to FIG. 1, auger  12  has an overall diameter, D 1 , which is the diameter from a top edge of the flight to the bottom edge of the flight. In particular, the auger diameter could theoretically be thought of as the diameter of a cylinder which is wrapped around the outer edges of the flighting, and thereafter measured for its diameter. Auger  12  has a further center tube diameter, D 2 . 
     It has been found to be advantageous to have the diameter of central tube D 2  be approximately 50 percent or less of the overall auger diameter D 1 . In particular, it has been found advantageous to have the diameter D 2  be approximately 25 percent of diameter D 1 . For example, if the overall auger diameter D 1  is equal to 24 inches, it has been found advantageous to have central tube diameter D 1  equal to six inches or 25 percent of the overall diameter. This construction of the various diameters has been found to allow a longer length header utilizing a longer length auger  12 . In particular, having the smaller inner tube  18 , smaller than those found in the prior art, allows a pitch between flights as indicated by the numeral “P” in FIG. 1 to be larger, thus creating a larger open space between flights and thus allowing the accommodation of larger amounts of material to flow inwardly through the auger and into the machine. It has been found that having an auger with the above ratio unexpectedly results in increased performance of the header resulting in more efficient material handling of the header, and less clumping or clogging of the header. As also indicated above, the header construction having such a ratio allows for an increased pitch “P” of the flighting, such that the increased flighting can have, for example, a 27-inch pitch which is beyond those normally found in prior art augers. 
     Additionally, triangular brace members  30  can be optional and spaced along each of the flightings  20 ,  22 ,  24  and  26 . Brace members  30  allow supporting of the flightings to inner tube  18 . 
     With reference to FIG. 2, central saw-toothed flightings  24  and  26  will now be described. In contrast to flightings  20  and  22 , flightings  24  and  26  have a saw-toothed edge instead of a smooth edge. This saw-toothed edging propels the material as it enters the central portion of the header through opening  28  and into the separator mechanisms of the combine. 
     With reference to FIG. 4, the advantageous tooth configuration is shown which has been found to increase the material handling capability of the central flighting  24  and  26 . In particular, it has been found advantageous to have an asymmetrical saw-toothed configuration. In particular, the saw teeth are defined by a plurality of valleys  32  which form the various saw teeth  34 . Each valley  32  is comprised of two angles A 1  and A 2 . It has been found advantageous to have the angle A 1  associated with the leading edge  36  to be 48 degrees. Further, it has been found advantageous to have the angle A 2  associated with the following edge  38  to be approximately 66 degrees. Again, these relevant angles have been found to increase the material handling capability of the central flightings  24 ,  26 . 
     Another advantage of the present invention has been found to be the ease with which the auger can be additionally supported in the central section by an additional bearing to prevent sagging of the auger. In particular, a relevant bearing can be positioned anywhere along the auger to add support. The fact that central tube  18  is much smaller than conventional tubes allows the ease of positioning of a bearing at any relevant position along the length of the auger and not necessarily at the edges. In particular, any sort of intermediate bearing can be attached to the back surface of the header for additional support. 
     From the foregoing, it will be seen that this invention is one well-adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter forth or shown in the accompanying drawings is to be interpreted as illustrative and not in sense.