Abstract:
A harvesting header includes a header frame, a cutterbar assembly mounted to the header frame, and a conveyor assembly supported behind the cutterbar assembly to receive crop severed by the cutterbar assembly. The conveyor assembly includes a pair of side conveyors and a fore-and-aft draper located between the side conveyors. The header further includes a central crop-conveying member that overhangs the rear margin of the fore-and-aft draper and a floor pan that at least partly defines a transition area. The floor pan presents a forwardmost edge adjacent to and rearward of the rear margin. The forwardmost edge is located above a lower run of the draper to direct severed crop materials from the upper run of the draper and to facilitate crop material flow through the transition area.

Description:
RELATED APPLICATION 
       [0001]    This application is a continuation of U.S. application Ser. No. 13/281,564, filed Oct. 26, 2011, which is a continuation of U.S. application Ser. No. 13/085,376, filed Apr. 12, 2011, which is a continuation of U.S. application Ser. No. 12/609,932, filed Oct. 30, 2009, which is a continuation of U.S. application Ser. No. 12/324,053, filed Nov. 26, 2008, which is a continuation application that is related to and claims the priority benefit of prior U.S. application Ser. No. 11/670,295, filed Feb. 1, 2007, which claims priority of prior Provisional Application No. 60/771,981, filed Feb. 10, 2006, all of which are hereby incorporated by reference into the present specification. 
     
    
     TECHNICAL FIELD 
       [0002]    This invention relates to harvesting equipment and, more particularly, to a draper header adapted for attachment to a combine harvester wherein the header is provided with a flexible cutterbar. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]      FIG. 1  is a left front isometric view of an embodiment of a draper header having a flexible cutterbar in accordance with the principles of the present invention; 
           [0004]      FIG. 2  is a left side elevational view thereof; 
           [0005]      FIG. 3  is a fragmentary, rear isometric view of the header; 
           [0006]      FIG. 4  is a fragmentary, front isometric view of a portion of the left end of the header illustrating details of construction; 
           [0007]      FIG. 5  is a fragmentary fore-and-aft cross-sectional view through the header illustrating the four-bar arm supporting linkage for the cutterbar; 
           [0008]      FIG. 6  is a left end elevational view of the header with drive mechanism and the end panel removed to reveal details of construction; 
           [0009]      FIG. 7  is a fore-and-aft cross-sectional view through the central portion of the header showing the center draper thereof; 
           [0010]      FIG. 8  is a fragmentary top plan view of the central portion of the header with structure removed to reveal details of construction; 
           [0011]      FIG. 9  is a bottom, right front isometric view of the center draper; 
           [0012]      FIG. 10  is a left, front isometric view of an alternative embodiment of a draper header having a flexible cutterbar and flexible draper in accordance with the principles of the present invention; 
           [0013]      FIG. 11  is a right, rear isometric view thereof; 
           [0014]      FIG. 12  is a fragmentary, top plan view of the header of  FIG. 10  with portions of the header removed and broken away to reveal details of construction; 
           [0015]      FIG. 13  is a transverse cross-sectional view through the header of  FIG. 10  taken substantially along line  13 - 13  of  FIG. 12  with the header in a fully lowered position; 
           [0016]      FIG. 14  is a transverse cross-sectional view through the header of  FIG. 10  similar to  FIG. 13  but showing the header in a fully raised position; 
           [0017]      FIG. 15  is a fragmentary, bottom isometric view of the right end of the cutterbar assembly showing details of construction; 
           [0018]      FIG. 16  is an enlarged, fragmentary, transverse cross-sectional view through the front of the header of  FIG. 10  illustrating the relationship between the draper assembly and the cutterbar assembly; 
           [0019]      FIG. 17  is a cross-sectional view through the attachment coupling between the front end of the draper assembly and the proximal ground skid taken substantially along line  17 - 17  of  FIG. 16 ; 
           [0020]      FIG. 18  is a transverse cross-sectional view through the header of  FIG. 10  taken along a sight line passing through the central conveyor thereof and showing the header fully lowered; 
           [0021]      FIG. 19  is an enlarged, fragmentary cross-sectional view similar to  FIG. 18  with the header fully lowered; 
           [0022]      FIG. 20  is a fragmentary, right front isometric view of the central conveyor of the header of  FIG. 10  with portions of the header removed to reveal details of construction; 
           [0023]      FIG. 21  is an enlarged, fragmentary, left rear isometric view of the header of  FIG. 10  showing the mounting adaptor frame of the header; and 
           [0024]      FIG. 22  is an enlarged, fragmentary cross-sectional view of one of the upright mounting members of the header frame and associated support arms of the header of  FIG. 10 . 
       
    
    
     DETAILED DESCRIPTION 
       [0025]    The present invention is susceptible of embodiment in many different forms. While the drawings illustrate and the specification describes certain preferred embodiments of the invention, it is to be understood that such disclosure is by way of example only. There is no intent to limit the principles of the present invention to the particular disclosed embodiments. References hereinafter made to certain directions, such as, for example, “front”, “rear”, “left” and “right”, are made as viewed from the rear of the machine looking forwardly. 
         [0026]    Header  10  has a frame at the rear thereof that includes an upper beam assembly  12  extending across the entire width of header  10 , and a lower beam assembly  14  that likewise extends across the full width of header  10 . A number of upright channels  16  interconnect beam assemblies  12 ,  14  across the backside of header  10  at spaced locations thereacross. Upright rear panels  18  on the front sides of channels  16  define an upright rear wall of the header, while a centrally located opening  20  in such panels serves as a crop outlet from header  10  to the feeder housing (not shown) of a combine harvester upon which header  10  may be mounted. Header  10  is also provided with left and right end panels  19 . 
         [0027]    Lower beam assembly  14  carries a number of arm assemblies  22  that project forwardly from beam assembly  12  at spaced locations along the length thereof. Each arm assembly  22  could comprise a single arm or, in another form of the invention as shown, a four-bar linkage having an upper link  24  and a lower link  26  that are respectively connected at their front ends by pivots  28  and  30  to a skid plate  32 . Links  24 ,  26  are pivotally connected at their rear ends to support assemblies  23  by rear pivots  25  and  27 , respectively ( FIG. 5 ). Arm assemblies  22  are biased yieldably upwardly by suitable biasing means, which in the illustrated embodiment comprises a compression spring assembly  29  ( FIG. 5 ). 
         [0028]    In some instances, such as at the opposite ends of the header  10 , only a single one of the arm assemblies  22  is attached to a skid plate  32 , while in other portions of the header two or more of the arm assemblies  22  may be attached to a single skid plate  32 . As illustrated in  FIG. 4 , adjacent ones of the skid plates  32  are hingedly interconnected by a web  34  of flexible material that spans the interface between adjacent skid plates  32  and is secured to such skid plates by suitable fasteners. A-frame assemblies  36  ( FIG. 4 ) are provided in association with the two leftmost skid plates  32  to assist in providing structural support for sickle drive mechanism as hereinafter described. 
         [0029]    A continuous, full length, flexible cutterbar  38  constructed of flat plate metal extends across the front of header  10  for its full width. Cutterbar  38  is secured to the front extremities of skid plates  32  by mounting lugs  40 . Carriage bolts  42  at the front ends of lugs  40  attach the same to cutterbar  38 , while the rear ends of lugs  40  are secured to skids  32  by suitable fastening means not shown. 
         [0030]    A series of side-by-side sickle guards  44  are bolted to the front edge of cutterbar  38  and project forwardly therefrom along the full length cutterbar  38 . A representative number of sickle guards  44  are illustrated on the cutterbar  38  in  FIG. 1 . A reciprocating sickle assembly  46  is carried by guards  44  for severing standing crop materials from the ground as header  10  is advanced. 
         [0031]    Header  10  may be provided with either a single such full-length sickle assembly  46  or with a split sickle assembly comprising two separate sickle assemblies that are driven by two separate mechanisms at opposite ends of header  10 . As is well known in the art, sickle assembly  46  may include a generally rectangular in cross section sickle bar  48  on which are secured a number of side-by-side knife sections  50 . 
         [0032]    A pair of left and right, center delivery draper assemblies  52  and  54  are located behind cutterbar  38  in disposition for receiving severed crop materials from sickle assembly  46  and moving such materials toward the center of header  10 . Drapers  52 ,  54  are spaced apart near the center of header  10  to define a generally rectangular in plan receiving opening  56  for crop materials from drapers  52 ,  54 . Each draper assembly  52 ,  54  comprises a wide, flat, endless draper belt that is looped around a pair of fore-and-aft rollers at opposite ends of the assembly.  FIG. 6  illustrates such a draper belt  58  wrapped around an outboard roller  60  at one end of the endless belt  58 . The other, inboard roller of left draper assembly  52  is not visible in the drawings, but such an inboard roller  62  is visible in  FIG. 7  in connection with right draper assembly  54 . Each pair of rollers  60 ,  62  is supported at its front end by a formed, generally Z-shaped, transversely extending member  64  and at its rear end by a transversely extending formed member  66  secured to the rear frame of header  10 . In addition, header  10  has a full width, generally Z-shaped support channel  68  extending the full width of header  10 . A feather plate  70 , which may be constructed in one or more sections, is attached to the rear edge of cutterbar  38  and extends upwardly and rearwardly therefrom to provide a transition for severed crop materials from sickle assembly  46  to drapers  52  and  54 . The rear extremity of feather plate  70  is supported on a forwardly projecting portion of the Z-shaped support member  64  of each draper assembly  52 ,  54 . 
         [0033]    A relatively short, center draper assembly  72  is disposed within receiving opening  56  for taking delivery of severed materials from left and right draper assemblies  52 ,  54  and feeding the materials upwardly and rearwardly through central opening  20  into the feederhouse of the combine harvester. As illustrated particularly in  FIGS. 7 and 9 , center draper assembly  72  includes a pair of transversely extending rolls  74  and  76  that are spaced apart in a fore-and-aft direction and are wrapped by an endless draper belt  78 . Preferably, draper belt  78  is slatted, as are the draper belts  58  of left and right draper assemblies  52 ,  54 . A pair of laterally spaced apart, fore-and-aft extending channels  80  support the rolls  74 ,  76  and are, in turn, supported at their rear ends by lower beam assembly  14  and at their front ends by transverse support channel  68 . A downwardly and rearwardly inclined ramp plate  82  leads from the rear extremity of feather plate  70  in the region of receiving opening  56  into overlapping relationship with the front extremity of center draper  72  for assisting in guiding materials that have been severed by the central portion of sickle assembly  46  into the center draper assembly  72 . A center-gathering auger  84  spans receiving opening  56  above the latter and in front of discharge opening  20  at the rear of center draper assembly  72  for consolidating crop materials from draper assemblies  52 ,  54  and  72  into a relatively low profile mat that can be handled by the conveying mechanism of the feederhouse into which the materials are fed. 
         [0034]    Header  10  is preferably adapted to be attached directly to the front end of the feederhouse of a combine harvester. However, one alternative embodiment would be for header  10  to be mounted upon an adapter which is, in turn, attached to the feederhouse. Such an adapter would have its own center draper, as well as overhead auger, in which event the center draper  82  and overhead auger  84  associated with header  10  of the present invention would not be utilized. It is also contemplated that a draper header may be connected directly to the feederhouse and have a rigid cutterbar rather than a flexible cutterbar. 
         [0035]    As illustrated in  FIGS. 6 and 7 , upper beam assembly  12  is provided with downwardly opening mounting pockets  86  that are adapted to matingly receive corresponding upwardly projecting mounting structure on the feederhouse. Rests  88  on top beam assembly  12  are disposed rearwardly adjacent pockets  86  for engaging top surface structure on the feederhouse to assist in supporting header  10  on the combine harvester. A pair of rearwardly projecting guides  90  ( FIG. 3 ) are disposed adjacent rests  88  and slightly outboard therefrom for the purpose of embracing opposite sides of the feederhouse and aligning central opening  20  with the mouth of the feederhouse. Multiple sets of receiving sockets  92  are disposed below central opening  20  in association with lower beam assembly  14  for receiving mounting projections on the feederhouse in an arrangement that depends upon the particular brand of combine harvester to which header  10  is mounted. 
         [0036]    The operating components of header  10  may be driven in any number of suitable ways. A variety of different mechanical and/or hydraulic drive systems could be utilized. In the particular illustrated embodiment, a transverse jackshaft  94  ( FIG. 3 ) at the rear of header  10  receives input driving power in an appropriate manner from the combine harvester upon which header  10  is mounted. Driving power from jackshaft  94  is brought to the front of the machine by a belt and pulley assembly  96  on left end panel  19 , which assembly  96  is operably coupled with a suitable mechanical sickle drive mechanism  98  as illustrated in  FIG. 2 . Sickle drive mechanism  98  is drivingly coupled with sickle assembly  46 . Although not illustrated herein, it will be understood that draper assemblies  52 ,  54  and  72 , as well as overhead auger  84 , may be hydraulically or mechanically driven by suitable drive systems. 
       Operation 
       [0037]    It is contemplated that in most operations header  10  will ride lightly along the ground with skids  32  engaging the surface of the ground. Suitable flotation springs (not shown) are preferably coupled with the feederhouse in such a way that the combined weight of the feederhouse and header  10  is carried in large measure by such flotation springs. Hydraulic means may be utilized in lieu of mechanical springs. On the other hand, if an adapter is used between the feederhouse and header  10 , such adapter may be attached rigidly to the feederhouse and the flotation means provided between the adapter and the header. It is also contemplated that header  10  might be locked in an elevated position off the ground for harvesting crops that do not require the sickle assembly  46  to sever the materials close to the ground. 
         [0038]    Assuming that header  10  is in its flotation mode rather than locked up for more elevated severance, skids  32  ride along the surface of the ground. As changes in terrain are encountered by different ones of the skids  32 , their respective support arm assemblies  22  swing downwardly or upwardly as the case may be to maintain the skid in contact with the ground. Cutterbar  38  flexes as necessary to accommodate such upward or downward ground-hugging action, as does sickle assembly  46 , without interfering with the reciprocating motion of sickle assembly  46  and the effective cutting action occurring between knife sections  50  and guards  44 . A typical range of flexing motion is illustrated in  FIG. 5 . 
         [0039]    As the crop materials are severed by sickle assembly  46 , they fall onto the drapers  52  and  54  to be delivered centrally in a gentle manner to receiving opening  56  and onto rearwardly moving center draper  72 . Although the particular disclosed embodiment contemplates that the front extremity of side drapers  52  and  54  will remain stationary relative to the flexing cutterbar  38 , it is within the principles of the present invention that the front extremities of side drapers  52  and  54  may likewise flex along with proximal portions of cutterbar  38 . 
         [0040]    As a result of the construction as herein above described, crops such as soybeans which require severance at the base of the plants can be readily handled by header  10 . Furthermore, once severed from the ground, they will be gently consolidated by drapers  52 ,  54  and  72  and presented to the feederhouse of the combine harvester for further processing. It will be appreciated that although not shown in the drawings, header  10  may be provided with an overhead reel for assisting in gently sweeping the crop materials into and against the reciprocating sickle  46  for severance. 
       Alternative Embodiment 
       [0041]      FIGS. 10-22  disclose details of a header  100  wherein the left and right draper assemblies, as well as the center conveyor assembly, flex up and down with the cutterbar assembly. Referring initially to  FIGS. 10 and 11 , header  100  has an upright frame  102  at the rear thereof that includes an upper, transverse beam  104  extending across the entire width of header  100 , and a lower, transverse beam  106  that is likewise full length and extends across the full width of header  100 . A plurality of upright frame members  108  interconnect beams  104 ,  106  at spaced locations across the back of header  100 . Upright panels  110  are secured to the front edges of members  108  to define an upright rear wall of header  100 . A centrally located opening  112  between a pair of the inboard upright frame members  108  serves as a crop outlet from header  100  to a combine feederhouse (not shown) upon which header  100  may be mounted. Header  100  is also provided with left and right end panel assemblies  114  and  116  respectively. 
         [0042]    A pair of left and right support arms  118 ,  120  project forwardly from upper beam  104  adjacent opposite ends thereof for supporting a harvesting reel (not shown for clarity) in overlying relationship to the front edge of header  100 . The reel is adjustably shiftable fore-and-aft along arms  118  as well understood by those skilled in the art and is driven by a drive assembly  122  carried on right arm  120 . 
         [0043]    Referring now to  FIG. 12  and others, each upright frame member  108  has an arm  124  pivotally attached thereto about a transverse pivot  126  (see also  FIG. 22 ) and projecting forwardly therefrom to the front extremity of the header. At their front ends, arms  124  are coupled with a flexible cutterbar assembly  128  that extends the full width of the header and is adapted for severing standing crop materials from the ground while also flexing along its length to accommodate changes in the terrain as encountered by different portions of the header. By virtue of their pivots  126 , arms  124  are adapted to swing up and down with cutterbar assembly  128  as it flexes during harvesting operations. 
         [0044]    Cutterbar assembly  128  includes a long, flat cutterbar  130  extending across the full width of header  100  and capable of flexing along its length. Cutterbar  130  has a series of sickle guard assemblies  132  bolted thereto along its front edge by bolts  134  for reciprocably supporting either a single, full-length sickle bar  136  or a double sickle comprising a pair of half-length sickle bars that extend only approximately one-half the width of the header and overlap in the center, all in a well-known manner. In the particular illustrated embodiment, a double sickle is illustrated, with each sickle bar  136  being driven by its own separate drive mechanism at one end of the header. The right sickle bar half has its own drive  150  ( FIGS. 12 and 15 ), while the left sickle bar half has its own separate drive  151  ( FIGS. 13 ,  14  and  18 ). As is well known, the sickle bars  136  are provided with knife sections that cooperate with the guard assemblies  132  to sever standing crop as the header advances through the field. 
         [0045]    Cutterbar assembly  128  also includes a transversely extending series of fore-and-aft ground-engaging skids  138  across the width of header  100  that are connected at their front ends with guard assemblies  132  via the bolts  134 . Skids  138  extend rearwardly and downwardly from their connection points with the guard assemblies  132  and underlie the front ends of support arms  124 . Skids  138  are slightly spaced apart along the length of the header as shown in  FIG. 12  so as to assure their independent movement relative to one another as changes in terrain are encountered across the width of the header. Flexible hinging webs (not shown) may be used to interconnect adjacent skids  138  if desired. 
         [0046]    Each arm  124  is connected at its forward end with a corresponding skid  138  by a coupling  140  (shown in detail in  FIGS. 16 and 17 ), which serves as the means by which arms  124  are connected to cutterbar assembly  128 . Each coupling  140  includes amounting component  142  fixed to the corresponding skid  138  and having an inverted, U-shaped looped body portion having a rigid collar  144  fixed interiorly thereof. Coupling  140  further includes a pivot bolt  146  projecting forwardly from the front end of the corresponding arm  124  and received within the recess or bore of collar  144 . A resilient bushing unit  148  surrounds pivot bolt  146  within collar  144  so as to provide a limited amount of relative movement between the arm  124  and skid  138  in several directions during flexing of cutterbar assembly  128 . 
         [0047]    Cutterbar assembly  128  further includes a series of rectangular, sloping support panels  154  ( FIGS. 12 and 16 ) along the rear edge of cutterbar  130  over the full width of the header (with the exception of the center conveyor yet-to-be described). Panels  154  overlie the front ends of the arms  124  and are attached by bolts  156  along their front edges to a transverse series of generally Z-shaped, formed members  158 . Members  158 , in turn, are secured at their front extremities to the rear edge of cutterbar  130  by bolts  160 . Bolts  156  also serve to attach and support a series of slightly Z-shaped hold down elements  161  to the members  158  for the purpose of partially overlying and holding down the front edges of belts of the draper assemblies as hereinafter explained in more detail. 
         [0048]    Each of the arms  124  can pivot independently of the others about its own rear pivot  126 . However, all of the arms  124  are also floatingly supported by a common flotation system broadly denoted by the numeral  162  for lightening the load on the skids  138 . Such flotation system could take a number of different forms such as, for example, springs, air bags, or hydraulic cylinders. 
         [0049]    Each arm  124  has a rearwardly projecting extension  164  to which the selected type of flotation device may be attached. Extension  164  is fixed to a transversely extending hub  166  that receives pivot  126  and is fixed to the rear end of the arm  124 . A pair of end-to-end, resilient bushing units  167  ( FIG. 22 ) are housed within hub  166  and surround pivot bolt  126 . In the particular embodiment disclosed herein, extension  164  at its rearmost extremity has a hydraulic, fluid pressure flotation cylinder  168  secured thereto, which is, in turn, connected at its upper end to the corresponding upright member  108 . 
         [0050]    In a preferred embodiment, flotation cylinders  168  are single-acting cylinders arranged such that as cylinders  168  are extended by hydraulic pressure, they force extensions  164  downwardly and thus the front ends of arms  124  upwardly, tending to lift or lighten cutterbar assembly  128 . In one preferred embodiment, flotation cylinders  168  are connected in a parallel fluid flow relationship with a source of hydraulic pressure (not shown) such that, while all of the cylinders  168  are exposed to the same pressure, movement of one cylinder such as during flexing of the cutterbar assembly  128  does not necessarily result in movement of a neighboring cylinder  168 . The flotation system may be such that arms  24  may be hydraulically locked in a raised position as shown in  FIGS. 14 and 16  with skids  138  off the ground to permit crop severance at an elevated level. As an alternative to the hydraulic lock, suitable mechanical means may also be provided. 
         [0051]    As illustrated, for example, in  FIG. 10 , draper mechanism for header  100  includes a pair of left and right, center discharge draper assemblies  170  and  172  located between cutterbar assembly  128  and frame  102 . Draper assemblies  170 ,  172  are driven in opposite directions in such a manner that they are adapted to feed severed crop material laterally in an inboard direction toward a central discharge opening  174  between opposite inboard ends of draper assemblies  170 , 172 . 
         [0052]    Using right draper assembly  172  as an example, each draper assembly  170 ,  172  includes a pair of opposite end rollers  176  and  178  ( FIG. 12 ) extending generally fore-and-aft between the rear wall panels  110  and cutterbar assembly  128 . Rollers  176 ,  178  lie in the same plane as, extend parallel to, and are supported by their next adjacent arms  124 . For example, with respect to inboard roller  178 , the adjacent arm  124  has a pair of front and rear brackets  180  and  182  adjacent opposite fore-and-aft ends thereof that rotatably support roller  178 . At the outer end of draper assembly  172 , the outermost arm  124  supports drive  150 , but the next inboard arm  124  has a pair of transversely extending, telescopically adjustable, cantilevered bars  184  and  186  that rotatably support opposite ends of roller  176 . Bars  184 ,  186  can be adjustably lengthened or shortened by appropriately turning an operating rod  190  having a rack and pinion type coupling with bars  184 ,  186 , all of which is for the purpose of adjusting the tension of draper assembly  172 . 
         [0053]    The outboard roller  176  is driven by a drive mechanism  192  that includes a pair of intermeshing bevel gears  194  and  196  that permit roller  176  to swing up and down with its supporting arm  124  about the pivot  126  of that arm without disengaging drive mechanism  192 . Drive mechanism  192  is operably coupled with an input drive shaft  198  that extends across the right rear portion of header  100 , which drive shaft  198  is also operably coupled with sickle drive  150  for the purpose or providing operating power to right draper assembly  172  and the right sickle bar half. A similar drive shaft  200  extends across the left rear half of header  100  ( FIG. 11 ) for supplying driving power to left draper assembly  170  and the left sickle bar half. 
         [0054]    Each draper assembly  170 ,  172  further includes an endless, flexible draper belt  202  entrained around opposite end rollers  176 ,  178  and presenting an upper run  202   a  and a lower run  202   b.  The upper run  202   a  of each belt  202  overlies all of the arms  124  associated with the draper assembly (except for the most outboard arm  124  that supports the drive for the corresponding sickle bar half), while the lower run  202   b  underlies such arms  124 . Thus, all of the arms  124  associated with each draper assembly are disposed within the draper belt  202 , with the exception of the most outboard arm  124 . The support panels  154  underlie the front portions of the draper belt  202  to assist in keeping belt  202  from sagging between arms  124  to a detrimental extent. 
         [0055]    Draper belt  202  has a plurality of elongated, laterally spaced apart, fore-and-aft extending slats  204  thereon for increasing the feeding ability of belt  202 . An upstanding, continuous rib  206  ( FIGS. 16 and 19 ) is formed on the exterior surface of belt  202  adjacent the leading edge thereof and forwardly of the terminations of slats  204  for assisting in keeping belt  202  positioned properly in a fore-and-aft sense on rollers  176 ,  178 . It will be seen that the hold down elements  161  overlie the front edge of belt  202  as illustrated in  FIGS. 16 and 19  to likewise assist in properly maintaining the position of belt  202  on rolls  176 ,  178  and for providing a cover or shield over the front edge of belt  202  where crop materials might otherwise enter and fall through. 
         [0056]    The discharge opening  174  between left and right draper assemblies  170 ,  172  is provided with a fore-and-aft conveyor  208  that receives severed materials from draper assemblies  170 ,  172  and transports them rearwardly toward outlet opening  112  in header frame  102 . Conveyor  208  is disposed lower than draper assemblies  170 ,  172  so severed materials always drop onto conveyor  208  upon leaving draper assemblies  170 ,  172 . Conveyor  208  is adapted to move up and down at its front end with the flexing cutterbar assembly  128  and proximal portions of draper assemblies  170 ,  172  so as to maintain a constant recessed relationship with the proximal inboard ends of draper assemblies  170 ,  172 , notwithstanding changes in the terrain. 
         [0057]    Conveyor  208  includes a pair of fore-and-aft extending, laterally spaced apart side plates  210  ( FIGS. 18 ,  19  and  20 ) that rotatably support a pair of front and rear rollers  212  and  214  respectively. Additionally, conveyor  208  includes an endless, flexible belt  216  entrained around rollers  212 ,  214  and having a series of crop-engaging slats  218  thereon. A formed metal panel  220  spans the two side plates  210  between rollers  212 ,  214  and inside of conveyor  208  to help rigidify the assembly and to prevent untoward sagging of the top run  216   a  of belt  216 . The rear drive shaft  222  associated with rear roller  214  is rotatably supported in a fixed position relative to lower beam  106  by mounting lugs  224  ( FIG. 20 ) fixed to beam  106 . Bearing assemblies  226  in the two side plates  210  rotatably receive drive shaft  222  and permit conveyor  208  to pivot up and down about the axis of drive shaft of  222 . A floor panel  228  of conveyor  208  extends between side plates  210  below the lower run  216   b  of belt  216  and projects forwardly beyond side plates  210  for connection with a number of the ground skids  138  via sliding connections  230  ( FIG. 19 ). Thus, when the skids  138  associated with the front end of conveyor  208  encounter terrain changes, conveyor  208  swings up or down as the case may be about the axis of rear drive shaft  222 . 
         [0058]    The rear end of conveyor  208  terminates just forwardly of the discharge outlet  112  within header frame  102  ( FIGS. 18 and 20 ). A stationary floor pan  232  ( FIG. 18 ) within discharge outlet  112  extends rearwardly from the rear end of conveyor  208  to a point rearwardly of header frame  102 . Pan  232  thus serves as a transition surface for flow of crop materials from header  100  into the front end of a feederhouse (not shown) on the combine to which header  100  is attached. A center-gathering, transverse auger  234  is disposed within outlet opening  112  and partially overlies both the rear end of conveyor  208  and transition floor pan  232  to help compress and feed the flow of materials rearwardly through outlet opening  112  and into the feederhouse. Left and right, oppositely inclined vanes  236  and  238  on the tube  240  of auger  234  help with these functions and also help consolidate the materials centrally. A drive shaft  242  within tube  240  of auger  234  is operably connected with a drive line  244  ( FIGS. 11 and 21 ) carried by a pair of the upright members  208  on the left side of outlet opening  112 , which drive line  244  is in turn operably coupled with the left input drive shaft  200  across the rear of header frame  102 . 
         [0059]    Header  100  is adapted for attachment to the feederhouse of a combine through the provision of an adaptor frame or bracket  246  ( FIGS. 2 ,  20  and  21 ) that is permanently attached to the rear of header frame  102  in generally surrounding relationship to outlet opening  112 . Adaptor bracket  246  is of rectangular, open box-like construction, presenting a horizontally extending top beam  248 , a horizontally extending bottom beam  250 , and a pair of left and right, generally upright side beams  252  and  254  respectively. Side beams  252 ,  254  rigidly interconnect top and bottom beams  248  and  250 . Side beams  252 ,  254  are situated on opposite lateral sides of outlet opening  112 , while top and bottom beams  248 ,  250  are situated above and below opening  112 . 
         [0060]    Adaptor bracket  246  is permanently attached to the rear of header frame  102  by a pair of left and right pivots  256  and  258  extending between side beams  252 ,  254  and the upright frame members  108  adjacent outlet opening  112 . Pivots  256 ,  258  are located generally midway between the upper and lower extremities of side beams  252 ,  254 . One or more turnbuckles or the like (not shown) may be provided between lugs  260  on top beam  248  and lugs  261  on upper beam  104  of header frame  102  for the purpose of allowing the angular relationship between adaptor frame  246  and header frame  102  to be adjusted. Thus, when adaptor frame  246  is secured to the feederhouse of a combine, the tilt of the header  100  can be adjusted relative to the feederhouse by correspondingly adjusting the turnbuckles. 
         [0061]    Top beam  248  is provided with mounting pockets  263  ( FIG. 18 ) similar to the mounting pockets associated with the first embodiment for matingly receiving corresponding upwardly projecting mounting structure on the feederhouse. A pair of rearwardly projecting guides  262  are fixed to respective ones of the side beams  252 ,  254  just below top beam  248  for the purpose of embracing opposite sides of the feederhouse and aligning outlet opening  112  with the mouth of the feederhouse. Multiple sets of receiving sockets  264  ( FIG. 21 ) are located within bottom beam  250  for receiving corresponding mounting projections on the feederhouse in an arrangement that depends upon the particular brand of combine harvester to which header  100  is attached. 
       Operation 
       [0062]    Header  100  may be operated either in a lowered position ( FIG. 13 ) in which ground skids  138  ride lightly along the ground, or in a raised position ( FIG. 14 ) in which skids  138  are out of contact with the ground. In the raised condition, which is more suitable for harvesting taller, small grain crops, the flexibility of cutterbar assembly  128  is not an issue as all parts of cutterbar assembly  128  are maintained constantly at the same height. Left and right draper assemblies  170 ,  172 , and center conveyor  208  are disposed in raised positions like cutterbar assembly  128  inasmuch as the front ends of draper assemblies  170 ,  172  and conveyor  208  are all connected to cutterbar assembly  128 . As noted earlier, cutterbar assembly  128  may be held in its selected raised position either hydraulically through suitable hydraulic lock mechanism in association with flotation cylinders  168  or mechanically through means not illustrated, or a combination of both. 
         [0063]    Assuming that header  100  is being operated in its lowered position with skids  138  engaging the ground, the flotation system  162 , including cylinders  168 , lightens the load on skids  138  to the extent selected by the operator. As skids  138  encounter rises or depressions, they are either lifted by the rise or allowed to drop into the depression as the case may be. Different portions of cutterbar assembly  128  are allowed to react to changes differently than other portions inasmuch as support arms  124  are free to pivot upwardly about the rear pivots  126  generally independently of one another. Corresponding portions of the left and right draper assemblies  170 ,  172  also flex upwardly or downwardly in concert with proximal portions of the cutterbar assembly  128  so as to maintain a constant height relationship between cutterbar assembly  128  and left and right draper assemblies  170 ,  172 . The front end of central conveyor  208  also flexes upwardly and downwardly with its corresponding portions of the cutterbar assembly  128  to stay in a constant height relationship therewith. 
         [0064]    Consequently, draper assemblies  170 ,  172  and center conveyor  208  are always in an appropriate position to receive materials cut by sickle bar  136  or materials that might be knocked free of their stems during severance and engagement by the reel. Moreover, it will be appreciated that the distance between the cutoff point at sickle bar  136  and the front edge of draper assemblies  170 ,  172  is shorter than is the case, for example, with respect to a construction wherein the draper assemblies do not flex with the cutterbar. In the header  100 , the transition area between sickle bar  136  and draper assemblies  170 ,  172  can be relatively short because cutterbar assembly  128  and draper assemblies  170 ,  172  are all moving up and down together. Thus, less crop loss can be expected, better feeding and control of the severed materials can be obtained, and productivity is increased. Moreover, the overall front-to-rear dimensions of header  100  can be decreased compared to conventional designs, which provides numerous efficiencies in manufacturing and transport. 
         [0065]    The inventor(s) hereby state(s) his/their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of his/their invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set out in the following claims.