Abstract:
A cornhead row unit is provided including first and second longitudinally extending stripper plates mounted on a frame and having opposed stripping edges which define a gap between them. The frame further includes a resilient device arranged and disposed to adjustably transversely urge the first stripper plate on the frame toward the second stripper plate to vary the width of the gap. An adjusting arrangement connecting the frame and the second stripper plate selectably and transversely moves the second stripper plate with respect to the first stripper plate to vary the width of the gap.

Description:
FIELD OF THE INVENTION 
     The invention relates in general to agricultural combines. It relates particularly to a corn harvesting header assembly for use with an agricultural combine. 
     BACKGROUND OF THE INVENTION 
     A corn harvesting header assembly or cornhead for an agricultural combine typically comprises a series of row units which are identical to each other. Each row unit includes a pair of snapping rolls having a snapping slot formed between them. Gathering chains having gathering fingers guide corn stalks into the snapping slot. The snapping rolls pull the corn stalks through the snapping slot and the ears are removed from the stalks as they come into engagement with opposed edges of stripper plates which bracket the slot between the gathering chains and the snapping rolls. 
     It is conventional for at least one of the two stripper plates to be mounted on the row unit frame for movement toward and away from the other plate. This movement permits the gap between the opposed stripping edges to be varied to accommodate different corn crops and crop conditions. Adjustment of the gap is typically accomplished by an adjusting mechanism including an actuation lever coupled to the adjustable stripper plate. 
     Coupling arrangements in use today vary, but typically, a tradeoff is made between part cost and durability. Durable or rugged designs normally result in increased part costs, but also provide increased service life. An example of a rugged actuation lever coupling arrangement presently in use is found in a corn harvesting header assembly produced by Deere &amp; Company. In the Deere construction, a longitudinally extending rod is welded to the underside of the adjustable stripper plate. A forked end on the actuation lever cooperates with the rod in a lost motion relationship while maintaining line contact to smoothly move the adjustable stripper plate transversely and, accordingly, vary the gap between opposed stripping edges of the stripper plates. 
     Whether insufficiently rugged or too expensive, actuation lever adjusting mechanism and coupling arrangements in use today do not completely satisfy the customer—the farm operator. The mechanism of the present invention was developed to provide the farm operator with a rugged, yet simple and inexpensive solution. 
     Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a cornhead row unit including first and second longitudinally extending stripper plates mounted on a frame and having opposed stripping edges which define a gap between them. The frame further includes a resilient device arranged and disposed to adjustably transversely urge the first stripper plate on the frame toward the second stripper plate to vary the width of the gap. A fluid ram connecting the frame and the second stripper plate selectably and transversely moves the second stripper plate with respect to the first stripper plate to vary the width of the gap. 
     The present invention further relates to a cornhead row unit including first and second longitudinally extending stripper plates mounted on a frame and having opposed stripping edges which define a gap between them. The frame further includes a resilient device arranged and disposed to adjustably transversely urge the first stripper plate on the frame toward the second stripper plate to vary the width of the gap. A fluid ram is connected to the frame. A mechanical device is connected between the fluid ram and the second stripper plate, so that in response to selective movement of the fluid ram with respect to the mechanical device, the mechanical device transversely moves the second stripper plate with respect to the first stripper plate to vary the width of the gap. 
     Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front-side perspective view of an agricultural combine mounting a corn harvesting header assembly. 
         FIG. 2  is a top-front-side perspective view of a row unit in the corn harvesting header assembly of  FIG. 1 , the row unit incorporating a stripper plate adjustment mechanism embodying features of the present invention. 
         FIG. 3  is a reverse top-front-side perspective view of a row unit in the corn harvesting header assembly of  FIG. 2  of the present invention. 
         FIG. 4  is a bottom view of the row unit of  FIG. 2  of the present invention. 
         FIG. 5  is an exploded top-front-side perspective view of a row unit in the corn harvesting header assembly of  FIG. 2  of the present invention. 
         FIG. 6  is a schematic of a portion of a hydraulic system of an agricultural combine mounting a corn harvesting header assembly of the present invention. 
         FIG. 7  is a schematic of a portion of a hydraulic system of a corn row unit of the present invention. 
     
    
    
     Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and particularly to  FIG. 1 , an agricultural combine of generally conventional construction is seen at  10 . A corn harvesting header assembly, header assembly or cornhead  12  is mounted on combine  10 , cantilevered in front of combine  10  and connected to the combine by a feeder assembly  14 . 
     Header assembly  12  illustrated contains four row units  16 , which harvest four rows of corn simultaneously. In other embodiments, the number of rows of corn that may be harvested may be different than four. Ears of corn are stripped from each of the four rows by a row unit  16  and then carried by an auger  18  in a trough  20  of a header assembly  12  to a feeder assembly  14 . Feeder assembly  14  carries the collected ears rearwardly and upwardly into a threshing assembly (not shown) in the body of combine  10 . 
     Referring now also to  FIGS. 2 and 3 , a row unit  16  is shown removed from header assembly  12 . Row unit  16  gathers corn stalks as the row unit moves forwardly along a row of corn. 
     Each row unit  16  includes a U-shaped frame  22  having legs  24 ,  26  on which each leg  24 ,  26  a gathering chain assembly (not shown) is mounted for endless circulation in paths parallel to each other. See U.S. Pat. No. 6,237,342, filed Sep. 19, 2002 (Becker), which is incorporated by reference in its entirety. The gathering chain assemblies each of which includes a series of gathering fingers (not shown) are designed to draw the stalks into a gap  28  defined between opposed edges  30 ,  32  of plates or stripper plates  34 ,  36 , respectively. Snapping rolls  38  ( FIG. 4 ) beneath stripper plates  34 ,  36  pull the corn stalks downwardly through gap  28  and the ears of corn are stripped off of the stalks by plates edges  30 ,  32  as the stalks are pulled downwardly between them. 
     The gathering fingers of the gathering chain assembly (not shown) carry the stripped ears of corn rearwardly into to trough  20 . There the ears of corn are deposited and conveyed by auger  18  to feeder assembly  14 . The stripped corn stalks are pulled through row unit  16  as feeder assembly  14  moves on through the field, with the stalks being left in the field. 
     In an exemplary embodiment, stripper plates  34 ,  36  are of substantially identical construction. Their opposed edged  30 ,  32 , respectively, define gap  28 . Stripper plate  34  is bolted through slots  40  in leg  24  of U-shaped frame  22 . The bolted or otherwise mechanically fastened connections through respective slots  40  of plate  34  permit plate  34  to move in a substantially transverse direction to leg  24 , such as in a direction  54 . Edge  30  of plate  34  is urged toward edge  32  of plate  36  by resilient devices  42 , such as springs. Resilient devices  42  are each retained in position by a frame  44  extending outward from a sidewall of leg  24 . In one embodiment, frame  44  includes an end cap  46  through which an elongated member  48 , such as a bolt or screw, the head of which member  48  is shown in  FIG. 3  to help retain resilient device  42  in an installed position. In addition, respective tabs  50  may extend from an edge  52  facing in a direction that is opposite of edge  30 , which tabs  50  further aiding in securing resilient device  42  in its installed position. To provide further control of transverse travel direction  54  of plate  34 , in addition to the bolted connections through slots  40 , a protrusion  56  may be aligned with a slotted opening  58  formed in plate  34 . In an exemplary embodiment, protrusion  56  includes parallel opposed surfaces such as a square head of a mechanical fastener that corresponds to similarly parallel opposed surfaces of slotted opening  58 . 
     Movement of plate  34  in transverse direction  54  may result in response to forces applied to resilient devices  42 , which movement toward edge  32  resulting when the combined forces of resilient devices  42  are greater than friction and/or forces opposing retention forces generated by resilient devices  42 . Alternately, movement of plate  34  away from edge  32  results when the combined retention forces of resilient devices  42  and friction are less than forces opposing the retention forces generated by resilient devices  42 . 
     Movement of plate  36  in a transverse direction  60  is now discussed. Referring to  FIG. 5 , a mechanical device  62 , such as a mechanical linkage includes a shaft  64  that is secured to an arm  66 . At least one protrusion  68 , and as shown in  FIG. 5 , a pair of protrusions  68 , outwardly extend from shaft  64 . Protrusion  68  may be welded or otherwise bonded to shaft  64  or may be of unitary construction in an alternate embodiment. As further shown in  FIG. 5 , a pair of brackets  70  are secured to leg  26 , such as by mechanical fasteners  72  to permit rotation of shaft  64  about a longitudinal axis  82  (i.e., perpendicular to transverse direction  60 ) of mechanical device  62  to leg  26 . In an alternate embodiment, brackets  70  could be welded, adhered or otherwise affixed to leg  26  by other methods or techniques. When mechanical device  62  is assembled to leg  26 , protrusions  68  are aligned with cross-shaped opening  74 . More specifically, protrusions  68  are aligned with the transversely extending portions  76  of opening  74 , which provides a longitudinal retention feature of mechanical device  62 . That is, protrusions  68  extending through transversely extending portions  76  of opening  74  prevent movement of mechanical device  62  along axis  82 . 
     To bring about movement of plate  36  in transverse direction  60 , an end of arm  66  opposite shaft  64  is moved in a transverse direction  78  (see  FIGS. 2 and 4 ). In response to this transverse movement, shaft  64  rotates about its longitudinal axis  82 , similarly rotating protrusions  68  about axis  82 . Protrusions  68  and transversely extending portions  76  of corresponding openings  74  are sized such that in response to a predetermined movement of arm  66  in one direction  78 , resulting in a similarly predetermined angular rotation of shaft  64  about axis  82 , protrusions  68  are brought into contact with the ends  84  of transversely extending portions  76 . Further movement of arms  66  in the same direction  78  results in movement of plate  36  in transverse direction  60  in the opposite sense as that of arm  66 . To bring about movement of plate  36  in the opposite transverse direction  60 , the end of arm  66  opposite shaft  64  is moved in a transverse direction  78  that is opposite that previously applied, until protrusions  68  are brought into contact with the opposed ends  84  of the opposed transversely extending portions  76 , with further movement of arm  66  in that direction resulting in movement of plate  36  in the opposite sense as that of arm  66 . That is, a transverse direction correlates to right or left movement, sufficient movement of arm  66  in direction  78  to the left results in movement of plate  36  in direction  60  to the right, and vice versa. 
     As further shown in  FIG. 5 , an end  86  of an adjusting arrangement, such as a fluid ram (not shown) may be secured by fasteners  72  to arm  66  of mechanical device  64  to bring about transverse movement of plate  36 . Optionally, a linkage  88  may be utilized to interconnect arms  66  of adjacent row units so that movement of end  86  of the fluid ram would simultaneously result in transverse movement of each corresponding plate  36  of each head row unit. It is to be understood that the fluid ram may be in fluid communication with a fluid system operating at an adjustable pressure level that is capable of providing a range of forces as required by the field conditions. In one embodiment the fluid system pressure level may be controlled remotely from plates  34 ,  36 , such as the combine cab, for convenience of the operator. 
     It is to be understood that in an alternate embodiment, an adjusting arrangement includes an electrical linear actuator. In a further embodiment, an adjusting arrangement includes transversely oriented slots configured and disposed with mechanical fasteners, permitting selective and transverse movement to be performed manually. However, the term powered adjusting arrangement is intended to refer to devices or systems that do not involve manual adjustment, such as a fluid ram or electrical linear actuator or the like. 
       FIGS. 6-7  schematically show different portions of a hydraulic system usable in an exemplary embodiment to control spacing between stripper plates  34 ,  36  of the present invention. For example, fluid ram  94  may be utilized to increase adjustability of resilient devices  42  or springs of fixed length associated with transverse movement  90  of stripper plate  34 . That is, fluid ram  94  may selectively move a support member  98 , acting as an adjustable end cap  46  ( FIG. 2 ). Fluid pressure P 5  applied to fluid ram  94  urges support member  98  toward stripper plate  34 , while fluid pressure P 6  applied to fluid ram  94  urges support member  98  away from stripper plate  34 . A position sensor S 2  may be used to monitor the position of support member  98 . 
     As further shown in  FIG. 7 , fluid ram  92  may be utilized to bring about transverse movement  90  of stripper plate  36 . That is, fluid ram  92  selectively moves a mechanical device  62 , utilizing fluid pressure P 4  applied to fluid ram  92  to rotatably urge stripper plate  36  toward stripper plate  34 , while fluid pressure P 3  is applied to fluid ram  92  to rotatably urge stripper plate  36  away from stripper plate  34 . A position sensor S 1  is used to monitor the position of mechanical device  62 . 
       FIG. 6  shows a pair of fluid rams  96  connected in parallel with the fluid pressure P 2  that is used to lift a header, which includes cornhead  12  ( FIG. 1 ), while fluid pressure P 1  is used to lower the header. 
     Components described in  FIGS. 6-7 , in which each fluid pressure P 1 -P 5  includes a pressure sensor (not shown, but similarly designated respectively as P 1 -P 5 ) may be associated with a controller  100  to effectively control the gap between stripper plates  34 ,  36  during corn harvesting, including conditions in which the cornhead is not in the harvesting contact with a corn row. Such conditions occur when the combine has completed harvesting of a corn row and is turning around, typically referred to as a “headland turn”, to resume harvesting of the adjacent and previously unharvested corn row. During execution of a headland turn, if the transverse force associated with resilient devices  42  or springs is excessive, due to the gap between stripper plates  34 ,  36  being too close to each other, upon resumption of harvesting in the subsequent corn row, sometimes referred to as “re-entry into the crop”, the cornstalks of the initially encountered corn row may not slide between the facing edges of stripper plates  34 ,  36 , causing the cornstalks to “lay over”, forcing the operator to reduce combine speed, until an adjustment of the gap between the stripper plates occurs. 
     In one embodiment, the adjusting arrangement, such as fluid ram  92 , and pressure sensor P 4  is associated with controller  100  and stripper plate  36 . In response to a pressure sensed by pressure sensor P 3  being less than a first predetermined pressure, controller  100  selectably controls the adjusting arrangement, such as fluid ram  92 , until the pressure sensed by the pressure sensor P 3  is between a first predetermined range that is at least equal to the first predetermined pressure. Such an arrangement maintains a minimum force that is applied by stripper plate  36  to a corn row being harvested. 
     In another embodiment, the adjusting arrangement, such as fluid ram  92 , and pressure sensor P 3  is associated with controller  100  and stripper plate  36 . In response to a pressure sensed by pressure sensor P 3  being greater than a second predetermined pressure, controller  100  selectably controls the adjusting arrangement, such as fluid ram  92 , until the pressure sensed by the pressure sensor P 3  is between a second predetermined range that is less than the second predetermined pressure. Such an arrangement limits a maximum force that is applied by stripper plate  36  to a corn row being harvested. 
     In a further embodiment, a lifting device associated with controlling a vertical position of the corn head row unit, such as fluid rams  96 , is a communication with controller  100 . In response to an operating parameter associated with a lifting device corresponding to a condition in which the corn head row unit is not in harvesting contact with a corn row, such as a headland turn, controller  100  selectably controls the adjusting arrangement, such as fluid ram  92 , to move stripper plate  36  to a predetermined gap from stripper plate  34 . Such operating parameters may include an increase in pressure level of P 2  applied to fluid rams  96 . Alternately, the operating parameter corresponds to a decrease in pressure sensor P 3  or P 5 , either or both of which may be connected in parallel with controller  100 , at least in a figurative sense, since any of the operating parameters may be an indicator of a headland turn. 
     Alternately, controller may be configured to maintain a predetermined gap for a predetermined time. Such a predetermined time would correspond to the time normally associated with executing a headland turn, to avoid the laying over of corn stalks of the re-entry corn row described above. 
     In yet a further embodiment, due to a variance in time associated with executing a headland turn, controller  100  may be configured to discontinue maintaining a predetermined gap between stripper plates  34 ,  36  prior to expiration of the predetermined time (i.e., the time normally associated with executing a headland turn), in response to a sufficient increase in the pressure sensed by a pressure sensor, such as pressure sensor P 3  or P 5 , indicative of completion of the headland turn and re-entry into the adjacent corn row. 
     It is to be understood that other conditions such as flow rate, may also be measured and included as an operating parameter as indicative of a headland turn. For example, an increase in flow to the portion of the hydraulic circuit associated with P 2  may be indicative of a headland turn. 
     While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.