Abstract:
Each row unit of a corn head can easily be converted between a first mode, wherein only ears are harvested, and a second mode, wherein ears together with stalks are harvested. In the first mode, a pair of snapping rolls is mounted for operation beneath each row unit frame for grasping corn stalks and pulling them downwardly through a narrow throat defined by a pair of laterally adjustable deck plates mounted to a top surface of the row unit frame. In the second mode, the snapping rolls are either removed or disabled and at least one stalk cutting disk is mounted on one of a pair of gathering chain drive idler shafts, mounted at the forward end of the row unit frame, for rotating above the frame. The snapping rolls are disabled by adjusting the deck plates toward each other to close the throat.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a row-crop combine harvester, and, more particularly, relates to a row unit arrangement for a corn head for such a harvester. 
     BACKGROUND OF THE INVENTION 
     Recently, designers have constructed row-crop combine harvesters so as to be able to collect a desired amount of crop residue (crop material other than grain) so that this residue can be used for conversion into fuel. However, during the normal process of harvesting corn, most of the stalk is left on the ground with the ears being removed from the stalk using snapping rolls and sent on into the separator and cleaning arrangements where kernels of corn are removed from the cob and other crop residue. U.S. Pat. No. 5,878,561 discloses a row crop harvester of this type. Recovering the stalk material left on the ground has required separate operations, for example, the use of a rotary cutter to sever the stalks from the ground and form a windrow, and the use of a baler to gather the stalks and form them into bales. It is also known to provide a conventional row crop harvester header with an attachment which cuts and windrows the stalks concurrently with the ears being snapped from the stalks. U.S. Pat. No. 4,148,175 discloses a device of this latter mentioned type. 
     In order to more efficiently gather the corn stalks, it would be desirable to collect them during the harvesting operation. While the row units of conventional combine harvesters for harvesting soy beans, milo or sunflowers are equipped with cutter arrangements for severing the stalks from the ground and with gathering devices including a grasping characteristic for grabbing the plant stalks and guiding the latter into cross-conveyors for narrowing the flow of crop to a width commensurate with that of a combine feeder house, these row units are not supplied with snapping rolls, and thus are not suitable for harvesting corn in situations where it is not desired to convey the entire stalk into the combine. U.S. Pat. No. 3,982,384 discloses a row crop harvesting header including row units designed for cutting and transporting the stalks of crops such as soybeans, milo or sunflowers into a combine for separation of the grain or seeds from the stalks and other crop residue. 
     Certainly it would be conceivable to construct a corn head for a combine with row units similar to those used for forage: harvesters, where a cutter or cutters is provided for cutting the corn stalks from the ground, but this would require one header to, be provided when it is desired to harvest only the ears and a completely separate header to be provided when it is desired to harvest stalks along with the ears, with the additional header being a substantial additional cost. 
     It is desired then to be able to provide a combine harvester with but a single header including row units designed for either collecting only ears from corn stalks or for collecting ears together with corn stalks during the harvesting operation. 
     SUMMARY OF THE INVENTION 
     According to the present invention, there is provided an improved combine harvester header including row units which can alternatively be used for removing the ears from corn stalks, which remain attached to the ground, or for severing corn stalks from the ground and conveying the stalks together with the ears to the separator of the combine. 
     An object of the invention is to provide a conventional combine harvester row unit equipped with stalk rolls and a gathering chain arrangement which cooperate for harvesting just the ears from corn stalks, and to provide optional equipment including at least a cutting arrangement adapted for being mounted to be driven together with the gathering chain arrangement in order to cut the corn stalks from the ground so that the stalks, together with the attached ears may be conveyed into the combine separator for processing. 
     A further object is to provide a harvester header arrangement, as stated in the foregoing object, wherein a shield arrangement is provided for covering the stalk rolls, or for covering the stalk roll drive shafts when the stalk rolls have been removed, when it is desired to harvest corn stalks along with the ears of corn. 
     Still another object of the invention is to provide a harvester header arrangement, as stated in one or more of the foregoing objects, wherein a gathering chain arrangement having an enhanced stalk grasping ability or characteristic is substituted for the row unit gathering chain arrangement, which may not have such a characteristic, when it is desired to harvest corn stalks. 
     These and other objects of the invention will become apparent from a reading of the ensuing description together with the appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of a conventional corn head for an agricultural combine, the corn head including row units which are particularly adapted for use with the present invention. 
         FIG. 2  is a left front perspective view of one of the row units. 
         FIG. 3  is a bottom view of the row unit shown in  FIG. 2 . 
         FIG. 4  is a left front perspective view of the row unit frame shown in  FIG. 2 . 
         FIG. 5  is a right front perspective view of the row unit shown in  FIG. 2  after it has been converted for harvesting entire stalks of corn together with the ears, but showing only the meshed, stalk-grasping sections of the belts carried by the gathering chains. 
         FIG. 6  is a view like that of  FIG. 5 , but omitting the gathering chains and showing an exploded view of the components associated with the left gathering chain, including those added for converting the row unit for harvesting entire stalks of corn. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to  FIG. 1 , there is shown a corn head  10  including a transversely extending frame  12  across the width of which is attached a plurality of forwardly projecting row units  14  spaced in side-by-side relationship to each other a distance commensurate with that of the spacing between adjacent rows of corn to be harvested, with it being noted that it is conventional to mount the row units  14  for transverse adjustment in order to accommodate various corn row spacings. Mounted to the row units  14  and serving to separate comingled stalks of adjacent rows from one another are crop dividers including right and left dividers  16  and  18 , respectively, at the opposite ends of the corn head  10 , and seven identical central dividers  20 , with the crop dividers defining longitudinal passages  22  between them which are centered relative to rows to be harvested and relative to a central fore-and-aft extending relatively narrow throat  24  defined by each row unit  14 , as described below in further detail. 
     Referring now to  FIGS. 2-4 , it can be seen that each row unit  14  includes a U-shaped row unit frame  26  ( FIG. 4 ) including right and left, fore-and-aft extending legs  28  and  30 , respectively, having rear ends joined by a bight portion  32 . As can best be seen in  FIG. 2 , right and left planar deck plates  34  and  36  are respectively secured to the planar top surfaces of the frame legs  28  and  30 , with the plates  34  and  36  having parallel opposed inner edges spaced apart so as to define the aforementioned narrow throat  24  which is adapted for receiving corn stalks of an aligned row as the row unit  14  proceeds along the row. The deck plates  34  and  36  may contain laterally elongated openings (not shown) receiving fasteners so that the deck plates may be adjusted laterally so that the throat  24  is closed for a purpose explained below. 
     Mounted beneath the bight portion  32  of the row unit frame  26  is a gear box  38  containing a pair of bevel gears (not shown) having parallel, upwardly projecting right and left gathering chain drive shafts  40  and  42 , respectively, mounted therein and projecting upwardly through circular openings  44  and  46  provided in the bight portion  32 . Right and left drive sprockets  48  and  50  are respectively mounted to upper end regions of the drive shafts  40  and  42 . Located at forward regions of the frame leg  28  and  30  are right and left chain tensioning assemblies respectively comprising flat slide bars  52  and  54  (see  FIG. 6 ) having up turned rear ends  56  and  58 . Mounted for rotation in forward ends of the bars  52  and  54  are right and left idler shafts  60  and  62 , and respectively mounted on the shafts  50  and  52  are idler sprockets  64  and  66 . Forming an endless loop about the right set of drive and idler sprockets  46  and  64  is a right gathering chain  68 , while a similar left gathering chain  70  is looped about the left set of drive and idler sprockets  50  and  66 . The gathering chains  68  and  70  each include a plurality of outwardly projecting lugs  72  spaced along the length of the chains, with the lugs  72  at inner runs of the chains  68  and  70  projecting into the associated throat  24  so as to engage stalks of plants located there during harvesting operation. It is noted that the slide bars  52  and  54  are respectively guided for fore-and-aft movement by elongate structures  74  and  76  that are located within the loops defined by the chains and serve as chain guides to prevent the opposed inner runs of the chains from deflecting outwardly relative to the throat  24 . The chain tensioning assemblies further include right and left coil compression springs (not shown) located within cylindrical housings  78  and  80 , and together with the housings being carried on right and left guide rods  81  and  82 . The guide rods  81  and  82  are in the form of bolts and are respectively inserted forwardly through first eyes  84  and  86  fixed to the deck plates  34  and  36 , with forward ends of the guide rods being respectively inserted through openings provided in brackets  88  and  90  that are respectively fixed to forward end locations of the guide structures  74  and  76 , with the guides being secured to the brackets  88  and  90  by sets of nuts  92  and  94 . The right coil compression spring is compressed between the eye  84  and the back side of the slide bar up-turned end  56 , while the left coil compression spring is compressed between the eye  86  and the back side of the slide bar up-turned end  58 . 
     As can best be seen in  FIG. 3 , a pair fore-and-aft extending snapping rolls  92  and  94  are mounted to a pair of snapping roll drive shafts  95  projecting forwardly from the gear case  38  and having forward ends respectively supported from the frame arms  28  and  30 , the snapping rolls thus being located beneath the deck plates  32  and  34  and being configured for drawing corn stalks down through the throat  24 , defined by the deck plates  32  and  34 , so as to cause the ears, which are too large to pass downwardly through the throat, to become detached from the stalks. 
     To this point, what has been described is conventional. 
     Referring to  FIGS. 5 and 6 , there is shown a row unit  14 ′ which results after converting one of the row units  14  in accordance with the principles of the present invention, with structure previously described being denoted with the same reference numerals used above. Instead of the gathering chains  58  and  60 , gathering chains  96  and  98  are provided which have a stalk grasping characteristic brought about by vertically disposed flat belts  100  and  102  being attached to vertical legs of L-shaped mounting clips  104  secured to each of alternate links of the respective chains so as to define a plurality of belt loops along the chain, with the loops of one chain intermeshing with the loops of the other chain at the inner opposed runs of the chains. Because the belts  100  and  102  have a vertical height greater than that of the gathering elements  72  of the gathering chains  68  and  70  of the row unit  14 , right and left elongate spacers  106  and  108 , respectively, are secured beneath the elongate guide members  74  and  76  so as to provide additional clearance for permitting the belts to travel over the deck plates  34  and  36 . Idler sprockets  110  and  112 , respectively, are substituted for the sprockets  64  and  66  and differ from these in that each is provided with four threaded bores spaced equally about the sprocket. Right and left cutter disks  114  and  116  each contain a set of four mounting holes  118  arranged in alignment with the threaded holes in the sprockets  110  and  112 , with the disks  114  and  116  being respectively connected for rotation with the sprockets  110  and  112  by bolts (not shown) inserted upwardly through the holes  118  and threaded into the sprockets. So that the sprockets  110  and  112  operate at the correct height above the deck plates  34  and  36 , a cylindrical spacer  120  (only one visible) is provided on each of the idler shafts  60  and  62  at respective locations above the slide bars  52  and  54 . 
     It is noted that the right and left cutter disks  114  and  116  are of a size and are mounted such that their respective scalloped cutting edges overlap slightly in a zone which is centered relative to a respective row of corn being harvested. Since the left cutter disk  116  passes over the top of the right cutter disk  114 , a spacer ring  122  is provided between the bottom of the disk  116  and an enlarged top of the cylindrical spacer  120 . The sprockets  110  and  112  and the associated cutter disks  114  and  116  are each secured in place by a nut  124  threaded onto the tops of each of the idler shafts  60  and  62  and tightened against a respective washer  126  engaged with top surfaces of the idler sprockets  110  and  112 . 
     The operation of the row units  14  and  14 ′ is similar in that the power for operating the row units is delivered by way of the gear housing  38  to the gathering chain drive shafts  40  and  42  supported by and projecting from the gear housing. However, although the snapping rolls  92  and  94  are likewise driven by power delivered by way of the gear housing  38 , these snapping rolls are not required for the function of the row units  14 ′ and may be disabled by removing the snapping rolls from their respective drive shafts and/or by adjusting the deck plates  34  and  36  towards each other so as to remove the throat  24 , thereby shielding the snapping rolls or their drive shafts from the stalks being cut by the cutter disks  114  and  116   
     Thus, it will be appreciated that in order to convert the corn head  10  for harvesting the entire stalk of corn together with the corn ear, it is possible to provide a conversion kit for each row unit  14  that includes tapped idler sprockets  110  and  112 , cutter disks  114  and  116 , gathering chains having a stalk grasping characteristic, such as the gathering chains  96  and  98  having stalk grasping belts  100  and  102 , and the various spacers  106 ,  108 ,  120  and  122 . 
     It is, to be noted that it might be possible to replace the gathering chains  68  and  70  with gathering chains constructed so as to have a stalk grasping characteristic by using stalk grasping elements that have a height substantially equal to the gathering elements  72  in which case all but the spacer  122  may be dispensed with. 
     Further, instead of providing a pair of cutter disks to perform the cutting function, it is possible to provide a single star-shaped cutter disk together with an idler sprocket for driving it and to provide a fixed counter knife and attaching hardware for securing the fixed counter knife to the frame legs  28  and  30  so as to span the space between the legs. The aforementioned U.S. Pat. No. 3,982,384 discloses such a cutter disk and knife, but differs from the instant application in that the cutter disk operates below the deck plate instead of above it as is necessary to accomplish the convertible aspect of the present invention. 
     Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.