PATENT ABSTRACT
The flexible header has a subframe removably coupleable to a feeder housing of the harvester. A pivot assembly is supported by the subframe permitting first and second header sections to pivotably move between raised and lowered positions together or independently of the other by actuating a hydraulic actuator coupled to the first and second header sections to selectively position the header sections when the ground elevation changes as the combine advances through the field while harvesting.

PATENT DESCRIPTION
BACKGROUND 
     Combine harvesters or combines are equipped with removable heads or “headers” that are designed for harvesting particular types of crops. A “platform header” is typically used for cereal grains such as soybeans and various cereal crops such as wheat, oats and barley. A platform header is equipped with a reciprocating knife cutter bar and has a revolving reel which forces the cut crop into the header as the combine advances. A cross auger forces the cut grain into the feeder house of the combine where the grain is threshed and separated from the cut stalk and other crop chaff “Draper headers” are similar to platform headers in that they utilize a reciprocating cutter bar and a revolving reel. However, instead of a cross auger, the draper header uses a fabric or rubber apron to feed the cut grain into the feeder house. Headers for row crops, particularly corn headers, are equipped with forwardly extending conical snouts which extend between the corn rows. Where adjacent snouts of the corn header converge, instead of cutting the stalk like a platform or draper header, adjacent stalk rollers pinch and pull the stalk downwardly stripping the corn ear from the stalk, so that the stalks pass under the header leaving primarily only the ear and husk enter the feeder house. 
     When combining or harvesting different crops using any of the foregoing types of headers, the header is typically operated at a height sufficiently low to the ground to ensure that the lowermost grain across the width of the header is not missed. As the crop varies in height or as the terrain varies across the field, the combine operator must adjust the height of the header up or down to ensure that the lowermost grain is not missed while also ensuring that no portion of the header runs aground. 
     Platform and draper headers can extend up to forty or more feet in width. Accordingly, to account for variations in terrain across the width of the header, especially for harvesting soybeans and other crops that have pods close to the ground, flexible platform and draper headers have been developed which utilize a cutter bar that flexes to better follow the contours of the terrain. However, heretofore, no such “flexible” header has yet been developed for row crops, particularly corn headers. With advances in combine technology, twelve and sixteen row corn headers have become common place and even twenty four row headers are now available. As a result, with corn headers now approaching the widths of platform and draper headers, there is now a need for corn headers to flex, bend or articulate so as to more closely follow the contours of the terrain to avoid missing corn. 
     For example, referring to  FIG. 5 , when combining over the crest of a hill with a large header of twelve rows or more, it may not be possible to lower the header sufficiently to avoid missing ears at the far ends of the header without running the header aground at the middle of the header. Likewise, referring to  FIG. 6 , when combining in a trough or valley between hills, it may not be possible to lower the header sufficiently to avoid missing ears in the middle of the header without running the header aground on the upwardly sloping hills at the far ends of the header. 
     While lateral tilt headers serve their intended purposes for operating on relatively uniform or consistent grades, the ability of the header to tilt laterally from side-to-side is not much more beneficial than a conventional fixed or non-titling header for harvesting on rolling terrain. For example, referring back to  FIGS. 5 and 6 , it should be appreciated that having the ability to laterally tilt the header to one side or the other will provide little or no benefit when harvesting over the crest of a hill as in  FIG. 5  or in a valley as in  FIG. 6 . Similarly, referring to  FIGS. 7 and 8 , when combining along the base of a hill, even when the header is tilted laterally and in the lower most position without running the header aground at the far ends, the ears in the corn rows in the middle of the header may still be missed. 
     Accordingly, for harvesting row crops on rolling terrain, there is a need for a row crop header, particularly a corn header, that articulates or flexes so that sections of the header can be raised and lowered to more closely follow the terrain to avoid missing rows as the combine traverses the field. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of a conventional combine harvester with a conventional fixed corn head or a lateral tilt corn head in the horizontal position. 
         FIG. 2  is a side view of the combine and corn head of  FIG. 1 . 
         FIGS. 3 and 4  are front views of a conventional combine with a conventional lateral tilt. 
         FIG. 5  is an illustration of a conventional header in the horizontal position on the crest of a hill and showing how the ears in the corn rows at the ends of the header will be missed because the corn ears are below the stalk rollers. 
         FIG. 6  is an illustration of a conventional header in the horizontal position in a valley between hills and showing how the ears in the corn rows in the middle of the header will be missed because the corn ears are below the stalk rollers. 
         FIGS. 7 and 8  are illustrations of a conventional header at the base of a hill and showing how the ears in the corn rows in the middle of the header will be missed because the corn ears are below the stalk rollers. 
         FIG. 9  is a front view of the combine of  FIG. 1  but with an embodiment of a flexible header in accordance with the claimed invention in the normal or level position. 
         FIG. 10  is a front view of the combine and flexible header of  FIG. 9  with the right side of the header raised. 
         FIG. 11  is a front view of the combine and flexible header of  FIG. 9  with the right side of the header lowered. 
         FIG. 12  is a front view of the combine and flexible header of  FIG. 9  with the left side of the header raised. 
         FIG. 13  is a front view of the combine and flexible header of  FIG. 9  with the left side of the header lowered. 
         FIG. 14  is a front view of the combine and flexible header of  FIG. 9  with both the left end and right sides of the header raised. 
         FIG. 15  is a front view of the combine and flexible header of  FIG. 9  with both the left end and right sides of the header lowered. 
         FIG. 16  is an illustration of the flexible header of  FIG. 9  on the crest of a hill and showing how, with the left and right sides of the header lowered, no ears will be missed because all corn ears across all of the rows of the header are above the stalk rollers. 
         FIG. 17  is an illustration of the flexible header of  FIG. 9  in the valley between hills and showing how, with the left and right sides of the header raised, no ears will be missed because all corn ears across all of the rows of the header are above the stalk rollers. 
         FIGS. 18 and 19  are illustrations of the flexible header of  FIG. 9  at the base of a hill and showing how, with one side of the header raised and the other side level, no ears will be missed because all the corn ears across all of the rows of the header are above the stalk rollers. 
         FIG. 20  is a perspective view of a preferred embodiment of a center pivot assembly of the flexible header of  FIG. 9 . 
         FIG. 21  is a front view of the center pivot assembly of  FIG. 20  and header frame in the normal or level position. 
         FIG. 22  is a front view of the center pivot assembly of  FIG. 20  and header frame with the left and right ends in the lowered position. 
         FIG. 23  is a front view of the center pivot assembly of  FIG. 20  and header frame with the left and right ends in the raised position. 
         FIG. 24  is a perspective view of a preferred embodiment of the auger center mount of the header of  FIG. 9 . 
         FIG. 25  is a rear elevation view of the left side of the flexible header of  FIG. 9  illustrating a preferred embodiment of the top and bottom slide bracket assemblies. 
         FIG. 26  is a rear elevation view of the left side of the flexible header of  FIG. 9  in the raised position showing the relative movement of the top and bottom slide bracket assemblies with respect to the slide plate. 
         FIG. 27  is a rear elevation view of the left side of the flexible header of  FIG. 9  in the lowered position showing the relative movement of the top and bottom slide bracket assemblies with respect to the slide plate. 
         FIG. 28  is a cross-sectional view of the top slide bracket assembly and the slide plate as viewed along lines  28 - 28  of  FIG. 25 . 
         FIG. 29  is a schematic illustration of an embodiment of the hydraulic system for the flexible header of  FIG. 9  wherein the left and rights sides of the header are raised and lowered together. 
         FIG. 30  is a schematic illustration of an embodiment of the hydraulic system for the flexible header of  FIG. 9  wherein the left and right sides are raised and lowered independently of each other. 
     
    
    
     DESCRIPTION 
     Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views,  FIG. 1  illustrates a conventional combine harvester  10  with a conventional corn head or header  12  mounted thereto in a conventional manner. As is typical, the header  12  includes a plurality of fore-and-aft extending row units  14 . In the illustration of  FIG. 1 , the header  12  is illustrated as a twelve-row header, in that there are twelve channels or spaces  16  formed between adjacent row units  14  into which the corn stalks in each row are gathered as the combine advances. 
     As disclosed in U.S. Pat. No. 5,195,309 to Mossman, which is incorporated herein in its entirety by reference, each row unit  14  comprises a semi-conical rearwardly converging snout  18  and a semi-cylindrical rearward portion or hood  20 . The snout  18  is typically made of polyethylene and includes a hardened or impact resistant point or tip. The snout  18  is pivotally mounted by bolts or pins (not illustrated) to the semi-cylindrical hood  20  which is fixed relative to the rest of the header. In operation, if the snout tip contacts the ground surface, the snout  18  will pivot upwardly about the pins to avoid damage to the snouts. A stop (not shown) prevents the snout  18  from pivoting downwardly past the general angle of the hood  20 . 
     In operation, the combine  10  and header  12  are positioned such that each snout is between adjacent corn rows. As the combine advances in the direction indicated by arrow  21 , the corn stalks are gathered between the rearwardly converging snouts  18 . Stalk rolls (not visible) positioned below adjacent sides of the hoods  20  pinch and pull the stalk downwardly to strip the ear from the corn stalk. Gatherer chains (not visible), also positioned below adjacent sides of the hoods  20  act as conveyors to move the stripped loose ears rearwardly into the rotating left and right cross augers  22 ,  23 . The cross augers  22 ,  23  move the ears toward the feeder house inlet opening  24  in the back wall  25  of the header  12 . The ears then pass into the feeder house opening  24  and into the feeder house  26  which conveys the ears into the interior of the combine for threshing and shelling. The husks, the shelled cobs, and other unwanted crop debris are discharged out the rear of the combine while the shelled corn kernels are augured up into the holding tank until being unloaded. 
     As illustrated in  FIGS. 3 and 4 , some combines are adapted to permit the header to be tilted from side-to-side. These “lateral tilt headers,” such as disclosed in U.S. Pat. No. 5,415,586 to Hanson et al. or U.S. Pat. No. 7,191,582 to Bomleny, both of which are incorporated herein in their entirety by reference, are well known in the art. Fixed headers and lateral tilt headers are referred to throughout this specification as “conventional headers” and are both designated by reference numeral  12 . 
     When harvesting under normal conditions, the header  12  is usually operated at a height where the bottom of the snouts  18  are a short distance above the ground surface to ensure that the stalk rolls and gathering chains are positioned below the ears as the combine advances and as the stalks are gathered between the snouts. However, when harvesting on rolling terrain, particularly with wide headers of twelve rows or more, it is often difficult, if not impossible, to position the header without missing some of the ears in some rows across the width of the header while not running one side or the other aground, or the middle of the header aground. 
     For example,  FIG. 5  is an illustration of a conventional header on the crest of a hill and showing how the ears in the corn rows at the ends of the header will be missed because the corn ears are below the stalk rollers. Similarly,  FIG. 6  is an illustration of a conventional header in a valley between hills and showing how the ears in the corn rows in the middle of the header will be missed because the corn ears are below the stalk rollers.  FIGS. 7 and 8  are illustrations of a conventional header at the base of a hill and showing how, even with the header  12  tilted laterally, the ears in the corn rows in the middle of the header will still be missed because the corn ears are below the stalk rollers. 
       FIG. 9  is a front view of the combine of  FIG. 1  but illustrating a preferred embodiment of a flexible corn head  100  coupled thereto in place of the conventional corn head  12 . Except as described in detail later, the preferred flexible corn head  100  is substantially identical to the conventional header  12 , including the manner and method of coupling it to the combine  10 , except that the flexible header  100  preferably includes an additional subframe  200 , a pivot assembly  300  which cooperates with one or more actuators to move sections of the header between raised and lowered positions, together or independently, and a modified auger center suspension assembly  400 . The flexible header  100  may be readily adapted from a conventional header  12  or it may be an original equipment manufacture (OEM). 
     In comparing  FIGS. 16-19  to  FIGS. 5-8  it should be appreciated that having the ability to move sections or wings of the header up and down permits the header to more closely follow the contours of the terrain thereby avoiding missed corn rows that occur with conventional headers  12 . When corn rows are missed, the operator is required to turn around in the field to separately pick the previously missed rows, resulting in wasted fuel and time, and thus, reducing profits. 
     Specifically, comparing  FIG. 5  to  FIG. 16 , where the combine is traveling along the crest of a hill, with the conventional header  12  ( FIG. 5 ) at its lower most position without running aground in the middle of the header, the ears at the far ends of the header will be missed because the ears are below the stalk rollers. However, with the flexible header  100  ( FIG. 16 ), the left and right wings of the header can be lowered to more closely follow the crest of the hill, thereby ensuring that the ears of the corn rows at the far ends of the header are above the stalk rollers and will not be missed. 
     Likewise, comparing  FIGS. 6 and 17 , where the combine is traveling in a valley between hills, with the conventional header  12  ( FIG. 6 ) at its lower most position without running aground at the far ends of the header, the ears in the middle of the header will still be missed because the ears are below the stalk rollers. However, with the flexible header  100  ( FIG. 17 ), both sides or wings of the header can be raised to more closely follow the converging sides of the hill, thereby ensuring that the ears of the corn rows in the middle of the header are above the stalk rollers and will not be missed. 
     Similarly, comparing  FIGS. 7 and 8  to  FIGS. 18 and 19 , where the combine is traveling along the base of a hill, with the conventional header  12  ( FIGS. 7 and 8 ) at its lower most position without running aground at the far ends of the header, the ears in the middle of the header will be missed because the ears are below the stalk rollers. However, with the flexible header  100  ( FIGS. 18 and 19 ), one side of the header can be raised while the other remains horizontal, to more closely follow the slope of the hill on the corresponding side of the combine, thereby ensuring that the ears of the corn rows in the middle of the header are above the stalk rollers and will not be missed. 
     Referring now to  FIGS. 20-24 , a preferred embodiment of a flexible corn header  100  is illustrated. As previously stated, the flexible corn header  100  is preferably substantially identical to the conventional header  12 , including the manner and method of coupling it to the combine  10 , except that the flexible header  100  preferably includes an additional subframe  200 , a pivot assembly  300  and a modified auger center suspension assembly  400  each of which is discussed in detail below. 
     As previously stated, the header  100  is preferably adapted from a conventional header  12 , although the header  100  could be an OEM manufacture. For purposes of this disclosure, the header  100  is hereinafter described and illustrated as a retrofit of an existing John Deere twelve row conventional header  12  that utilizes a central auger suspension system such as disclosed in U.S. Pat. No. 4,300,333 which is incorporated herein in its entirety by reference. The retrofitted header  12 , includes a top beam  102  (best viewed in  FIGS. 21 and 24 ), as well as an intermediate beam  104  ( FIG. 20 ), bottom beam  106  ( FIG. 20 ) and row unit support beam  108  ( FIG. 20 ), all of which extend the full width of the header. Posts  110  extend between the top beam  102  and the intermediate beam  104 . The header  12  also includes a back wall  25  that encloses the back side of the header except at the feeder house inlet  24 . Those of ordinary skill in the art will understand that depending on the header make and model being retrofitted (or if it is an OEM manufacture) particular structural components of the header referred to in this description may not be present or may have a different configuration than shown and described. 
     As best illustrated in  FIGS. 20 and 24 , a section of the top beam  102  is removed to accommodate the subframe  200  (discussed below) and a section of the intermediate beam  104 , bottom beam  106  and the row unit support beam  108  are removed to accommodate the pivot assembly  300  (discussed later). Because a section of the intermediate and bottom beams  104 ,  106  is removed, a stiffening plate  112  is preferably added to maintain the vertical spacing between the beams and the structural integrity of the header. 
     The subframe  200  preferably comprises a top member  202 , left and right vertical members  204 ,  206  and a bottom member  208  welded together to define an interior frame opening having dimensions preferably corresponding in size to the feeder house inlet  24  of the header  100 . Although not shown, the subframe  200  preferably includes or incorporates recesses to receive lugs and latch pins typical of conventional quick-connect header mounts. 
       FIG. 25  is a rear view of the left side of the subframe  200 . The right side is a mirror image of the left side. A slide plate  210  extends outwardly from the left vertical member  204  and includes upper and lower arcuate edges  212 ,  214 . A wear plate  216  such as high molecular weight (HMW) polyethylene or like material is preferably secured by countersunk tapping screws (not shown) or other suitably secure connection, to the front face of the slide plate  210 . The wear plate  216  reduces wear and friction between overlapping surfaces (described later) as the header sections or wings are raised and lowered as best illustrated in  FIGS. 26-27 . 
     It should be appreciated that because the center of gravity of the header is forward of the subframe  200 , and because the top beam  102  is no longer supported directly by the feeder house, the header  100  will tend to tip forwardly which would exert substantial bending stress on the pivot pins of the pivot assembly  300  (discussed later). Accordingly, to reduce the amount of bending stress on the pivot pins, upper and lower slide brackets  220 ,  222  are provided to prevent the header from tipping forwardly. As illustrated in  FIGS. 25-27 , these slide brackets  220 ,  222  receive the arcuate edges  212 ,  214  of the slide plate  210  respectively.  FIG. 28  is a cross-sectional view of the slide brackets  220 ,  222  as viewed along lines  28 - 28  of  FIG. 25 . Each of the slide brackets  220 ,  222  include a rear plate  224  that is secured by a plurality of threaded connectors  226  to a threaded spacer block  228  welded to the face of the fill plate  230 . Continuing to refer to  FIG. 28 , a wear member  216  is also secured to the inside face of the rear plate  224  thereby sandwiching the slide plate  210  between front and back wear plates  216 . As the wings of the header pivot about the pivot pins as illustrated in  FIGS. 26-27 , the arcuate edge  212 ,  214  slide within the arcuate upper slide bracket  220  and the lower slide brackets  222 , respectively. 
     Referring to  FIG. 20 , the pivot assembly  300  preferably comprises two rotatable or pivotable bushings  310 ,  312  disposed over parallel pins  314 ,  316  fixedly secured at their rearward end to the bottom member  208  of the subframe  200 . Sleeves  318 ,  320  are disposed over the forward ends of the pins  314 ,  316  and are secured to a base plate  322  by vertical supports  324 ,  326  thereby retaining the bushings  310 ,  312  on the pins  314 ,  316 . A lateral spacing plate  328  is also secured to the retainer sleeves  318 ,  320  and to the base plate  322  thereby maintaining the lateral spacing and parallel relationship of the pins  314 ,  316  and bushings  310 ,  312 . The bushings  310 ,  312  are thus able to freely pivot about the stationary pins  314 ,  316 . End caps  334 ,  336  are secured to the cut ends of the row unit supports  108  and to the bushings  310 ,  312 . The rearward ends of the bushings  310 ,  312  are secured to the stiffener plate  112 . Additionally, gussets  338  are welded to the bushings  310 ,  312  and to the intermediate and bottom beams  104 ,  106 . Accordingly, it should be appreciated that as viewed in  FIG. 20 , and as best illustrated in  FIGS. 21-23 , the left and right ends of the header  100  are pivotable, respectively, about the longitudinal axis  330 ,  332  of pins  314 ,  316  by actuation of the left and right actuators  302 ,  304 . 
     In a preferred embodiment, the pins  314 ,  316  are preferably fabricated from two 2½ inch diameter machined steel rods. The bushings  310 ,  312  are preferably comprised of four inch outside diameter sleeves having a ¾ inch wall thickness. The forward end sleeves  318 ,  320  are preferably comprised of 3½ inch outside diameter sleeves having ½ inch wall thickness. The pins  314 ,  316  are preferably press fit into 2½ inch diameter spaced holes drilled through bottom member  208  of the subframe  200 . The bottom member  208  is preferably fabricated from eight inch by 1½ inch thick steel plate. 
     It should be appreciated that in order for the left and right sections of the header  100  to pivot about the axis  330 ,  332 , the auger pan (not shown) must also be cut or split. However, in order to prevent the corn ears and other crop debris from falling through and passing under the split auger pan when one end of the header is raised relative to the other, a vertical baffle plate  340  is provided which projects a short distance above the auger pan. 
     Referring to  FIGS. 21-23 , it should also be appreciated that the hood  20  of the center row unit spans the pivot assembly  300 . Thus, the hood  20  of the center row should also be cut along its centerline to allow the respective sides of the hood to move relative to the other as each side of the header is raised or lowered. To prevent the corn ears and other crop debris from falling through the cut hood  20  of the center row, a hood cover plate (not shown) may be provided that is supported by the stationary vertical baffle plate  340  and which extends over the cut edges of the center row hood  20 , thereby ensuring the cut edges of the center hood remain covered as they move below the stationary cover plate. 
     It should also be appreciated that in order for the left and right sides or wings of the header  100  to pivot about the axis  330 ,  332 , the left and right cross auger sections  22 ,  23  must also move with their respective left and right header sections. Accordingly, referring to  FIGS. 21-24 , to permit the auger sections  22 ,  23  to move with the header sections, an auger center suspension assembly is required that moves with the respective left and right header sections. A preferred embodiment of a auger center suspension assembly  400  is best illustrated in  FIG. 24  in conjunction with  FIGS. 21-23 . 
     The preferred auger center suspension assembly  400  preferably comprises left and right top beam extensions  402 ,  404  ( FIG. 24 ) welded to the cut top beam  102  and extending inwardly toward the center of the header. Center support brackets  406 ,  408  are secured to the inward opposing ends of the beam extension  402 ,  404 . The center support brackets  406 ,  408  preferably include a dogleg to minimize the distance between the opposing end of the left and right auger sections  22 ,  23 , thereby minimizing axial interruption of the auger flighting, while at the same time preventing the brackets  406 ,  408  from interfering with each other as the header sections are raised and lowered as best illustrated between  FIGS. 22 and 23 . Other than the dogleg, each center support bracket  406 ,  408  preferably features the elements disclosed in U.S. Pat. No. 4,300,333 previously incorporated herein by reference. 
     Continuing to refer to  FIGS. 21-24 , the edge  410  of the fill plate  230  adjacent the feeder house inlet  24  is preferably cut at an angle, so that when the left and right header sections are raised, the edge  410  aligns with the inside edge of the subframe  200  (see  FIG. 23 ). It should be appreciated that when comparing  FIGS. 21-23 , if the edge  410  of the backwall was not cut at an angle, the feeder house inlet opening would be partially blocked by the inside edge of the backwall when either or both sides of the header is raised. 
       FIG. 29  schematically illustrates one method of coupling the actuators  302 ,  304  to the combine&#39;s hydraulic system. Hydraulic lines  502 ,  504  are coupled at one end to the combine&#39;s hydraulic system  500  and at the other end to a flow control valve  506 . Left and right cylinder lines  508 ,  510  and left and right return lines  512 ,  514  are coupled between the flow control valve  506  to the left and right actuators  302 ,  304 , respectively. With the hydraulic circuit of  FIG. 29 , both cylinders  302 ,  304  are actuated simultaneously such that both wings of the header raise and lower together as illustrated in  FIGS. 14 and 15 . However if the combine includes a lateral tilt feeder house, the feeder house can be tilted to cause the opposite wing of the header to be level while the other wing is raised or lowered such as illustrated in  FIGS. 10-13 . 
       FIG. 30  schematically illustrates another method of coupling the actuators  302 ,  304  to the combine&#39;s hydraulic system. The hydraulic circuit of  FIG. 30  is identical to the circuit of  FIG. 29  except that first and second open/close valves  516 ,  518  are disposed along the cylinder feed lines  508 ,  510 . By inserting the valves  516 ,  518 , each wing of the cylinder is able to raise and lower independently of the other wing. 
     Those of ordinary skill in the art will appreciate that although the forgoing disclosure is particularly directed toward a corn header, the teachings herein could be applied to any row crop header. Furthermore, those of ordinary skill in the art will appreciate that although the preferred pivot assembly disclosed and illustrated herein utilizes two laterally spaced pins disposed along the center axis of the header, the pivot assembly may be disposed anywhere along the length of the header, or there may be multiple pivot assemblies disposed along the length of the header. Additionally, those of ordinary skill in the art will appreciate that the pivot assembly may comprise a single pivot pin supporting two rotatable bushings as opposed to two parallel pins each supporting a rotatable bushing. Furthermore, those of ordinary skill in the art will appreciate that the header may utilize a single actuator to raise and lower the header sections together or independently. 
     The foregoing description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment of the apparatus, and the general principles and features of the system and methods described herein will be readily apparent to those of skill in the art. Thus, the present invention is not to be limited to the embodiments of the apparatus, system and methods described above and illustrated in the drawing figures, but is to be accorded the widest scope consistent with the spirit and scope of the appended claims.