QUICK ADJUST SHEARBAR MECHANISM

Abstract: An adjustable shearbar apparatus for a forage harvester is disclosed wherein a pair of levers (32) pivotally supported to effect positional adjustments of the shearbar (20) are mounted such that the pivot axis is located in an offset relationship relative to the axis of the shearbar (20). An upper clamping member (24) is detachably connected to a lower support mechanism (23) by a threaded member (25) positioned in line with the shearbar axis to clamp the shearbar (20) therebetween. A connecting apparatus detachably affixing the shearbar (20) to each of the levers (32) includes a threaded fastener (41) received through an opening (43) extending through each lever (32) and threadably engaged with the shearbar (20). The connecting apparatus also includes cupped washer assemblies (45) to create a ball joint effect to facilitate the relative movement between the levers (32) and the corresponding fasteners (41), permitting the shearbar (20) to be moved linearly by a pair of pivotally movable levers (32).

Description: The present invention relates generally to precision type forage harvesters utilizing knives mounted to a cutterhead for cooperative action against a shearbar to chop crop material and, more particularly, to a quick adjust mechanism for facilitating the adjustment of the positional relationship between the shearbar and the moveable knives. Typically, quick adjust shearbar mechanisms utilize mechanical linkages to move the shearbar relative to the rotating knives. One such adjustable shearbar apparatus can be seen in U.S. Patent No. 4,436,248. The problems encountered in such shearbar adjustment mechanisms, i.e. mechanisms in which the mechanical linkages induce movement of a clamped in place shearbar, involve bowing of the shearbar, torque fluctuations encountered in the shearbar clamping bolts, and difficulties in the serviceability due to the general complexity of the adjustment mechanism. Accordingly, it is the objective of the present invention to overcome these problems. More specifically, it is the objective to provide a shearbar adjustment mechanism on a forage harvester with improved serviceability and which eliminates the shearbar bowing problems as well as the torque fluctuation problems in the shearbar clamping means. According to the invention a forage harvester is provided having a cutterhead assembly including a rotary cutterhead with a plurality of knives, which, upon rotation of the cutterhead, are cooperable with an elongated shearbar positioned at a minimal spacing from the cutterhead knife path so that crop material fed to the cutterhead is comminuted between the cutterhead knives and the shearbar; the cutterhead assembly further also including a shearbar adjustment mechanism for adjusting the spacing of the shearbar from the cutterhead knife path and which comprises adjacent each end of the shearbar : - support means for supporting the shearbar in an aperative position relative to the cutterhead knife path; - clamping means cooperable with the support means and the shearbar to urge the latter against said support means and held it in the operative position relative to the cutterhead knife path during normal operation; - a lever pivotally mounted proximate to the support means for pivotal movement relative thereto; - transmission means between the lever and the corresponding shearbar end; and - shifting means connected to the lever for pivotally moving said lever to effect adjustment movement of the shearbar relative to the cutterhead knife path; and the forage harvester further being characterized in that each transmission means detachably affixes a corresponding lever to a corresponding shearbar end and comprises a ball joint type coupling means permitting the shearbar (20) to be moved linearly by the pivotal movement of said lever (32). Preferably the support means adjacent both ends of the shearbar are formed by a single elongated support member of substantially the same length as the shearbar and which is connected to opposing side sheets of the cutterhead assembly and extends generally therebetween across the full width of the cutterhead and beneath the shearbar. The clamping means are formed by clamping members connected to the support member adjacent the corresponding shearbar ends and which are engageable with said corresponding shearbar ends to urge the shearbar against the support member. Preferably the clamping members are generally aligned with the longitudinal shearbar axis and are detachably connected to the support member by threaded members and dowels positioned in line with the shearbar axis. The clamping members clamp the shearbar to the support member in a direction at a right angle to the direction of adjustment movement of the shearbar. The clamping force exerted by the clamping members on the shearbar is such as to positionally retain the shearbar relative to the support member during normal operation of the harvester on the one hand and to permit adjustment movement of the shearbar relative to the cutterhead knife path upon actuation of the shifting means on the other hand. The pivotal mounting of each lever is located in offset relationship relative to the shearbar axis which preferably is rearwardly of said shearbar axis as seen in the direction of operative travel of the harvester. This offset pivotal mounting of the levers permits said levers to be positioned closer to the cutterhead chamber, thus reducing the span between the levers. This reduced span between adjustment levers reduces shearbar deflections. Each lever is pivotally mounted on a pivot member defining a pivot axis which preferably extends parallel to the shearbar axis. Each said pivot member is at least partially supported by the support member. Each transmission means includes a threaded fastener received through an opening extending through the corresponding lever and threadably engaged with the shearbar. The coupling of each transmission means to the corresponding shearbar end is positioned relative to the corresponding clamping member such that the lines of action of the adjustment force transmitted through said transmission means to the shearbar and of the clamping force exerted by the corresponding clamping member on said shearbar generally intersect each other, preferably at right angles. The opening through each lever is larger than the corresponding threaded fastener to accommodate relative movement therebetween when pivotal movement of said levers induces linear movement to said shearbar. The ball joint type coupling means of each transmission means includes at least one cup-and-ball washer assembly in register with the opening in the lever and through the openings of which the threaded lever extends to facilitate said relative movement while permitting the shearbar to be clamped tightly against the levers. preferably a cup-and-ball washer assembly is positioned on either side of the lever in register with the opening therein. Each fastener may be in the form of a capscrew received through the openings in each cup-and-ball washer assembly and which is operable to positionally fix the shearbar relative to the ball joint type coupling means. Each capscrew preferably is positioned in the plane defined by the pivotal movement of the corresponding lever. The shifting means for controlling the pivotal movement of the levers may comprise motor means which can be energized to adjust the shearbar. Another advantage of this invention is that accuracy of the shearbar adjustment is improved which in turn provides better machine operating efficiency. Also shearbar clamp bolt torque fluctuations are reduced and finally a quick adjust shearbar mechanism for a forage harvester is provided which is durable in construction, in expensive of manufacture, facile in assemblage and simple and effective in use. The advantages of this invention will become apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein: Fig. 1 is a partially side elevational view of a cutterhead assembly for a forage harvester, incorporating the principles of the instant invention; Fig. 2 is a partial cross-sectional view taken along lines 2-2 of Fig. 1 to show the apparatus for positionally supporting the shearbar; and Fig. 3 is an enlarged partial cross-sectional view of the shearbar support apparatus taken along lines 3-3 of Fig. 2. The terms "forward", "rearward", "left" and "right" etc. used in connection with the forage harvester and/or components thereof are determined with reference to the direction of forward travel of the machine but should not be construed as limiting. Referring now to the drawings and, particularly to Fog. 1, a partial side elevational view of a cutterhead assembly for a forage harvester, such as shown in U.S. Patent No. 4,436,248, the description of which is hereby incorporated herein by reference, can be seen. The forage harvester 10 includes a side sheet 12 which at least partially defines a cutterhead chamber 13 and rotatably supports a cutterhead 15 for rotation about an axis of rotation 16. The cutterhead 15 is provided with a plurality of knives 17 detachably affixed thereto in a conventional manner about the circumference of the cutterhead 15 for rotation in the direction indicated by arrow 18. A pair of feed rolls 19 feed a mat of crop material over a shearbar 20 positioned in a cooperative relationship with the rotating knives 17 to effect a comminuting of the mat of crop material by the shearing action between the knives 17 and the shearbar 20. Referring now to Figs. 1-3, the elongated shearbar 20 extends across the entire transverse width of the cutterhead 15 and is supported at either end 21 exteriorly of the side sheet 12 by a lower support member 23 and an upper clamping member 24. The end 21 of the shearbar 20 is clamped between the upper clamping member 24 and the lower shearbar support member 23 by a clamp bolt 25 extending through the upper clamping member 24 and threadably engaged with the lower support member 23. A dowel 27 positionally retains the upper clamping member 24 relative to the lower support member 23. Both the clamp bolt 25 and the dowel 27 at each end 21 of the shearbar 20 are positioned in line with the transverse axis of the shearbar 20. The adjustment mechanism 30 includes a lever 32 pivotally supported on each respective side sheet 12 about a pivot member 33 defining a pivot axis. The pivot member 33 is supported by a collar 34 affixed to the respective side sheet 12 and a bracket 36 detachably affixed to the lower support member 23 by a fastener 37 and a positioning pin 38. The levers 32 are then pivotally movable in generally a fore-and-aft direction generally parallel to and along the exterior of the side sheet 12. Each respective lever 32 is connected to the corresponding end 21 of the shearbar 20 by a capscrew 41 extending through an oversized opening 43 in the levers 32 into a threaded engagement with the corresponding end 21 of the shearbar 20. As best seen in Fig. 3, a pair of cooperable cup-­ and-ball washers 45 positioned on opposing sides of the respective levers 32 give a "ball joint" effect to permit a positional rotation of the levers 32 relative to the corresponding capscrews 41, allowing a generally linear motion of the shearbar 20 and engaged capscrews 41 while that the levers 32 are pivoted about their pivot members 33 defining the pivot axis thereof rearwardly of the shearbar 20. As best seen in Fig. 1, manipulation of the actuation linkages 47 caused movement of the levers 32 about the pivot members 33. The relative rotative movement between the cup-and-ball washer assemblies 45 creating a "ball joint" effect, permits the levers 32 to be rotatably moved about the pivot members 33 while effecting a substantially linear motion of the shearbar 20 between lower support members 23 and the upper clamping members 24 by pulling on the capscrew 41. This motion permits a positional adjustment of the shearbar 20 relative to the rotating knives 17 to selectively acquire the proper cooperation therebetween for effecting the most efficient chopping of crop material fed by the feed rolls 19. The positioning of the pivot members 33 for the levers 32 rearwardly of the lower shearbar support members 23, as seen in the direction of forward operative travel of the harvester, allows the levers 32 to be positioned closer to the cutterhead sidesheets 12 thereby reducing the span between the two levers 32 and thus reducing possible shearbar deflections. Furthermore, with the levers 32 pivotally positioned as described above, the upper clamping members 24 can be positioned so that the clamping loads exerted thereby on the shearbar are positioned within the generally vertical and fore-­ and-aft extending planes defined by the pivotal movement of the respective levers 32. Thereby any bending movement created from heretofore known offset clamping positions is avoided. In this respect it is remarked that for adjusting the position of the shearbar 20 relative to the cutterhead knife path it is not necessary to release the clamping bolts 25. Indeed, these clamping bolts 25 should be tightened sufficiently to positively hold the shearbar 20 in the operative position during normal operation on the one hand, but should not prevent the adjustment relative to the cutterhead knife path through pivotal movement of the pivot levers 32 on the other hand. This is made possible by orienting the clamping forces at right angles to the direction of shearbar adjustment relative to the cutterhead knife path. The positioning of the upper clamping members 24 so that the clamping loads are positioned within the vertical planes defined by the pivotal movement of the respective levers 32, minimizes torque variations on the clamp bolts 25 because the shearbar 20 and the upper clamping member 24 are both supported on the lower shearbar support 23. The positioning of the levers 32 behind the lower shearbar support 23 permits a connection between the shearbar 20 and the lever 32 to be accomplished with a single capscrew on each side of the cutterhead 15. This capscrew 41 clamps the shearbar 20 against ball joint effect washer assemblies 45 to allow the levers 32 to rotate while the shearbar 20 moves linearly. This simple clamp arrangement also allows for easier shearbar removal for replacement or turning. It will be understood that changes to the details, materials, steps and arrangement of parts which have been described and illustrated to explain the nature of this invention will occur to and may be made by those skilled in the art upon reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description may be employed in other embodiments without departing from the scope of the invention. As an example, in one arrangement the actuation linkages 47 may have threaded ends upon which nuts are provided in engagements with a frame member of the machine. Manipulation of the linkages 47 thus is accomplished using a wrench to turn said nuts against frame member whereby the linkages 47, cause the levers 32 to pivot. In an alternative arrangement the linkages 47 may be coupled to hydraulic or electric motors which can be energized e.g. from the operator's platform. Each linkage 47 may have its own motor, or, alternatively, both linkages 47 may be coupled to a single motor. As far as the cup-and-ball washer assemblies 45 are concerned, it will be clear to those skilled in the art that these assemblies can be substituted by other coupling means provided the "ball joint" effect is maintained.

Claims: 1. A forage harvester (10) having a cutterhead assembly including a rotary cutterhead (15) with a plurality of knives (17) which, upon rotation of the cutterhead (15), are cooperable with an elongated shearbar (20) positioned at a minimal spacing from the cutterhead knife path so that crop material fed to the cutterhead (15) is comminuted between the cutterhead knives (17) and the shearbar (20); the cutterhead assembly further also including a shearbar adjustment mechanism (30) for adjusting the spacing of the shearbar (20) from the cutterhead knife path and which comprises adjacent each end (21) of the shearbar (20) : - support means (23) for supporting the shearbar (20) in an operative position relative to the cutterhead knife path; - clamping means (24) cooperable with the support means (23) and the shearbar (20) to urge the latter against said support means (23) and hold it in the operative position relative to the cutterhead knife path during normal operation; - a lever (32) pivotally mounted proximate to the support means (23) for pivotal movement relative thereto; - transmission means (41, 43, 45) between the lever (32) and the corresponding shearbar end (21); and - shifting means (47) connected to the lever (32) for pivotally moving said lever (32) to effect adjustment movement of shearbar (20) relative to the cutterhead knife path; characterized in that each transmission means (41, 43, 45) detachably affixes a corresponding lever (32) to a corresponding shearbar end (21) and comprises a ball joint type coupling means (45) permitting the shearbar (20) to be moved linearly by the pivotal movement of said lever (32). 2. A forage harvester according to claim 1, characterized in that the support means adjacent both ends (21) of the shearbar (20) are formed by an elongated support member (23) of substantially the same length as the shearbar (20) and which is connected to opposing side sheets (12) of the cutterhead assembly and extends generally therebetween across the full width of the cutterhead (15) and beneath said shearbar (20). 3. A forage harvester according to claim 2, characterized in that the clamping means are formed by clamping members (24) connected to the support member (23) adjacent the corresponding shearbar ends (21) and engageable with said corresponding shearbar ends (21) to urge the shearbar against said support member (23). 4. A forage harvester according to claim 3, characterized in that the clamping members (24) are generally aligned with the longitudinal shearbar axis. 5. A forage harvester according to claim 3 or 4, characterized in that the clamping members (24) are detachably connected to the support member (23) by threaded members (25) positioned in line with the shearbar axis. 6. A forage harvester according to any of the claims 3 to 5, characterized in that a dowel (27) positionally retains each clamping member (24) relative to the support member (23); said dowel (27) being positioned in line with the shearbar axis. 7. A forage harvester according to any of the claims 3 to 6, characterized in that the clamping members (24) clamp the shearbar (20) to the support member (23) in a direction at a right angle to the driection of adjustment movement of the shearbar (20); the clamping force exerted by the clamping members (24) on the shearbar (20) being such as to positionally retain the shearbar (20) relative to the support member (23) during normal operation of the harvester on the one hand and to permit adjustment movement of the shearbar (20) relative to the cutterhead knife path upon actuation of the shifting means (47) on the other hand. 8. A forage harvester according to any one of the preceding claims, characterized in that the pivotal mounting of each lever (32) is located in offset relationship relative to the shearbar axis. 9. A forage harvester according to claim 8, characterized in that each lever (32) is pivotally mounted on a pivot member (33) defining a pivot axis; each said pivot member (33) being at least partially supported by the support member (23) rearwardly of the shearbar axis as seen in the direction of operative travel of the harvester. 10. A forage harvester according to claim 9, characterized in that the pivot axis of each pivot member (33) extends parallel to the shearbar axis. 11. A forage harvester according to any of the preceding claims, characterized in that each transmission means (41, 43, 45) includes a threaded fastener (41) received through an opening (43) extending through the corresponding lever (32) and threadably engaged with the shearbar (32). 12. A forage harvester according to claim 11 when appended to any one of the claims 3 to 7, characterized in that the coupling of each transmission means (41, 43, 45) to the corresponding shearbar end (21) is positioned relative to the corresponding clamping member (24) such that the lines of action of the adjustment force transmitted through said transmission means (41, 43, 45) to the shearbar (32) and of the clamping force exerted by the corresponding clamping member (24) on said shearbar (32) generally intersect each other. 13. A forage harvester according to claim 12, characterized in that the said lines of action intersect each other at right angles. 14. A forage harvester according to anyone of the claims 11 to 13, characterized in that the opening (43) through each lever (32) is larger than the corresponding threaded fastener (41) to accommodate relative movement therebetween when pivotal movement of said levers (32) induces linear movement to said shearbar (20). 15. A forage harvester according to claim 14, characterized in that the ball joint coupling means of each transmission means (41, 43, 45) includes at least one cup-and-­ ball washer assembly (45) in register with the opening (43) in the lever (32) and through the openings of which the threaded fastener (41) extends to facilitate said relative movement between the lever (32) and the corresponding fastener (41) while permitting the shearbar (20) to be clamped tightly against the levers (32). 16. A forage harvester according to claim 15, characterized in that the ball joint coupling means of each transmission means (41, 43, 45) comprises cup-and-ball washer assemblies (45) positioned on either side of the lever (32) in register with the opening (43) therein and through the openings of which the threaded fastener extends. 17. A forage harvester according to claim 16, characterized in that the fastener is a capscrew (41) received through the openings in each cup-and-ball washer assembly (45) and which is operable to positionally fix the shearbar (20) relative to the ball joint coupling means. 18. A forage harvester according to claim 17, characterized in that each capscrew (41) is positioned in the plane defined by the pivotal movement of the corresponding lever (32). 19. A forage harvester according to anyone of the preceding claims, characterized in that the shifting means (47) comprise motor means which can be energized to adjust the shearbar (20).

Inventors: MARTENAS, WAYNE B.
Applicants: FORD NEW HOLLAND, INC. (A DELAWARE CORP.)
Application year: 1986
Main classification: A01F29
IPC codes: A01F29