WO2012166666A1

WO2012166666A1 - Pivoting knife arm assembly for a sickle

Info

Publication number: WO2012166666A1
Application number: PCT/US2012/039728
Authority: WO
Inventors: Luke A. Schroeder
Original assignee: CNH Amercia LLC
Current assignee: CNH Industrial America LLC
Priority date: 2011-05-27
Filing date: 2012-05-25
Publication date: 2012-12-06
Anticipated expiration: 2013-11-27

Abstract

The knife arm assembly (66) for connecting an epicyclic sickle drive mechanism (62A, 62B) to the knife (58) of a sickle (30), has a pivoting knife arm (68) having a mounting end (70) connected to a shuttle element (98) of the epicyclical drive mechanism (62A, 62B) driven in a reciprocating linear motion by a pinion (102) of the mechanism (62A, 62B), a distal end (72) opposite the mounting end (70), and a pivot (74) at a location between the mounting end (70) and the distal end (72), the mounting end (70) being connected to the shuttle element (98) with an eccentric bearing arrangement (80) for translating reciprocating the linear movements of the shuttle element (98) into limited reciprocating pivoting movements of the knife arm (68).

Description

Description PIVOTING KNIFE ARM ASSEMBLY FOR A SICKLE

[0001] This application claims the benefit of U.S. Provisional Application No. 61/491,039, filed May 27, 2011.

Technical Field

[0002] This invention relates generally to a pivoting knife arm assembly for the sickle of a header of an agricultural cutting machine, such as a combine, windrower or other crop harvesting machine, or a mower, and more particularly, for connecting a sickle knife assembly to an epicyclic drive mechanism, which utilizes a multiple race eccentric bearing arrangement adapted for translating reciprocating linear motion of the epicyclic drive to a pivoting arc motion.

Background Art

[0003] The disclosure of U.S. Provisional Application No. 61/491,039, filed May 27, 2011, is hereby

incorporated herein in its entirety by reference.

[0004] Sickles typically including cutter bars supporting a row of knives, have been used to cut plants, including, but not limited to, hay, grasses, small grains and the like, for many years. The knives are composed of a plurality of knife or sickle sections which are mounted in side by side relation forming an elongate metal knife assembly. The elongate knife assembly is normally supported so as to slide

longitudinally along an elongate stationary bar that has forwardly projecting, spaced apart guards bolted to a structural beam. The knife assembly moves back and forth in a reciprocating movement to move the knives relative to the guards so that the leading knife edges of the knives cross over the guards or through slots in the guards . This produces a shearing or cutting action which severs plant stems and stalks or other material captured between the knives and the guards.

[0005] In a harvesting machine, such as a combine or windrower, the knife assembly and stationary bar are typically supported in connection with a cutting head or header, and are oriented so as to extend sidewardly along a forward edge portion of structure such as a floor or pan of the header, hereinafter sometimes referred to generally as the floor. The floor or pan defines the lower periphery of a cut crop or plant flow area, which can include conveying apparatus, such as one or more augers or belts, operable in cooperation with a reel in machines so equipped, for conveying the cut plant material and crops, for instance, to a feeder inlet of a combine or windrow forming apparatus of a windrower .

[0006] Historically, many known sickle drive

mechanisms have been located on the side end of the sickle, and connect to the knife assemblies utilizing connecting rods or Pitman arms, such as illustrated in Wanamaker, U.S. Patent No. 1,622,299, issued March 29, 1927, and Boyer, U.S. Patent No. 2,332,840, issued October 26, 1943. An observed shortcoming of these older drives, however, is that the drive rods or arms are obtrusively positioned in the cut plant flow area. The ball joints are advantageous as they accommodate misalignments of the knife assemblies relative to the stationary support structure, but they are inefficient for directing the motive power or drive forces in the desired direction longitudinally along the knife assemblies, that is, sidewardly along the length of the sickle. [0007] More recent known side located sickle drives are less obtrusive and connect to the end of the knife assembly with a connection that better directs the motive power longitudinally along the knife assemblies. Reference in this regard, Regier et al . , U.S. Patent No. 7,121,074 Bl issued October 17, 2006. An observed advantage of this drive it is that it utilizes

epicyclical motion translated to the sideward

reciprocating motion by connecting components that allow motion in one plane only, as opposed to the multiple plane motion afforded by the ball joints of the older drives, while allowing for or accommodating slight misalignment of the knife assemblies in the stationary supporting structure, the stationary bar.

[0008] Other more recent sickle drives are adapted to be located in or below the floor or pan of a header or plant cutting machine, as shown in Priepke U.S. Patent Nos. 7,810,304; 7,805,919; 7,730,709; 7,520,118; and 7,401,458, and Bich et al . , U.S. Patent No. 8,011,272. Theses drives are compact, and theoretically provide an efficient manner of translating epicyclic motion to side to side sickle motion such that the motive forces are directed substantially longitudinally along the knife assemblies. However, these drives utilize knife arms that attach to the sickle knife assemblies and extend rearwardly to a connection to the drive, and in actual use are subjected to high loading conditions that can damage the knife arms. These damaging loading

conditions have been found to be at least in part a result of the required length of the knife arms.

[0009] Thus, what is sought is a knife arm assembly for connection of an epicyclic sickle drive to the knife assembly of a sickle which provides good power

transmission, and smooth operation, but in a manner that reduces potentially damaging loading conditions exerted against the knife arm, and which overcomes one or more of the shortcomings and limitations, set forth above.

Summary Of The Invention

[ 0010 ] What is disclosed is a knife arm assembly for connection of an epicyclic sickle drive to the knife assembly of a sickle which provides good power

[ 0011 ] According to a preferred aspect of the invention, the knife arm assembly includes a pivoting knife arm having a mounting end for connection to an output element of the epicyclical drive, a distal end opposite the mounting end, and a pivot at a location between the mounting end and the distal end, the mounting end carrying a multiple race eccentric bearing arrangement for translating reciprocating linear movements of the shuttle element into limited

reciprocating pivoting movements of the knife arm.

[ 0012 ] According to another aspect of the invention, the shuttle element is connected in driven relation to an eccentric output element of the epicyclic drive so to be capable of reciprocating linear motion. The pivot of the knife arm is at a fixed location such that the knife arm pivots about a fixed pivotal axis and the mounting end will travel along a known or predetermined arcuate path. The eccentric bearing arrangement connects the knife arm to the shuttle element, such that the shuttle element is limited to a predetermined path of

reciprocating linear movement or action while the knife arm is pivoted, with the bearing arrangement

automatically adjusting for a continuously changing distance between a path of linear movement or action of the shuttle element and the arcuate path of the mounting end of the knife arm. To facilitate or enable this, the bearing arrangement has eccentricity substantially equal to a maximum distance between the arcuate path of the pivotal movement of the mounting end of the knife arm and the path of the linear movement of the shuttle element .

[ 0013 ] According to another preferred aspect of the invention, the bearing arrangement comprises a triple race eccentric bearing sized to have the required eccentricity to compensate for the changing distance between the arcuate path of movement of the mounting end of the knife arm and the linear path of the shuttle element .

Brief Description Of The Drawings

[ 0014 ] FIG. 1 is a fragmentary side view of a harvester including a header having knife arm assemblies of the invention connected in reciprocating driving relation to a sickle of the header;

[ 0015 ] FIG. 2 is an enlarged fragmentary side view of the header and knife arm assemblies of the invention;

[ 0016 ] FIG. 3 is a front view of the harvester and header, showing the location of the knife arm

assemblies;

[ 0017 ] FIG. 4 is a fragmentary perspective view of the header, showing aspects of the sickle and the knife arm assemblies;

[ 0018 ] FIG. 5 is an enlarged fragmentary side view within the header, showing an enclosure containing a pair of epicyclical drives connected in driving relation to the knife arm assemblies, and showing the connection to the sickle;

[ 0019 ] FIG. 6 is an enlarged fragmentary top view of the enclosure and knife arm assemblies; and [ 0020 ] FIG. 7 is a further enlarged fragmentary top view of one of the knife assemblies.

Detailed Description Of The Invention

[ 0021 ] Turning now the drawings wherein a

preferred embodiment of the invention is shown, in FIGS. 1 through 5, a conventional, well known agricultural cutting machine, which is a combine 20, is shown including a header 22. Header 22 is shown supported in the conventional, well-known manner on a forward end 24 of combine 20, and is operable for cutting or severing crops such as, but not limited to, small grains such as wheat and soybeans, and inducting the severed crops into a feeder 26 for conveyance into combine 20 for threshing and cleaning, in the well known manner, as combine 20 moves forwardly over a field.

[ 0022 ] Header 22 includes a pan or floor 28 which is supported in desired proximity to the surface of the field during the harvesting operation, and an elongate, sidewardly extending sickle 30 along a forward edge portion 32 of floor 28, sickle 30 being operable for severing the plants or crop for induction into header 22, as will be explained. Header 22 additionally includes an elongate, sidewardly extending reel 34 disposed above sickle 30 and rotatable in a direction for facilitating induction of the severed plant material or crops into header 22. Here, header 22 is configured as a draper type, having a system of elongate, flat, sidewardly moving draper belts 36 and 38 having upwardly facing surfaces disposed just rearwardly of forward edge portion 32, operable in cooperation with reel 34 for conveying the severed plant material or crops toward an inlet opening of feeder 26 for induction into combine 20, in the well-known manner. [ 0023 ] Referring more particularly to FIG. 3, sickle 30 extends in a sideward direction along the width of floor 28, between a first side edge portion 40 of the floor, and an opposite second side edge portion 42.

Sickle 30 includes an elongate, sidewardly extending first cutter bar assembly 44, and an elongate,

sidewardly extending second cutter bar assembly 46 extending in end to end relation to cutter bar assembly 44, cutter bar assemblies 44 and 46 being supported in substantially longitudinally aligned relation adjacent to forward edge portion 32 of floor 28.

[ 0024 ] Referring more particularly to FIGS. 4 and 5, cutter bar assemblies 44 and 46 each include a plurality of sidewardly facing aligned slots 48 through a

sidewardly extending array of guards 50 which project forwardly from a stationary bar 52 at sidewardly spaced intervals therealong. Stationary bar 52 extends the length of sickle 30 just forwardly of forward edge portion 32 of floor 28, and guards 50 are mounted to bar 52 with fasteners 54. Bar 52, in turn, is mounted to a frame 56 of header 22 adjacent to forward edge portion 32 by fasteners 54, as best illustrated in FIG. 5. Each of cutter bar assemblies 44 and 46 supports an elongate knife assembly 58 for reciprocating longitudinal movement within slots 48, each knife assembly 58 having a row of knife sections 60 including oppositely facing, angularly related knife edges which, in conjunction with adjacent guards 50, effects a shearing or cutting action which severs plant stems and stalks or other material captured between the knives and the guards as the knife sections are reciprocatingly moved sidewardly, as denoted by arrow A in FIG. 4.

[ 0025 ] Knife assemblies 58 are reciprocatingly driven utilizing first and second epicyclic sickle drives 62A and 62B. First and second sickle drives 62A and 62B are illustrated in FIGS. 3 and 4 at a center location on header 22 between side edge portions 40 and 42 at the opposite ends of the header, although it should be noted that it is contemplated that sickle drives 62A and 62B could alternatively be utilized at other locations on a header, and that multiple sickle drives 62 could be used at multiple locations on a header. Sickle drives 62A and 62B are preferably located completely within or beneath floor 28, in a suitable enclosure or case, as best shown in FIG. 5, to reduce interruption of flow of cut plant material thereover and thereabout. Drives 62A and 62B can comprise a variety of epicyclical drive mechanisms operable to output purely linear motion. The disclosures and teachings of Priepke U.S. Patent Nos . 7,810,304; 7,805,919; 7,730,709; 7,520,118; and

7,401,458; and Bich et al . , U.S. Patent No. 8,011,272, are hereby incorporated by reference herein in their entireties, as representative non-limiting examples of drives and principles of operation that can be utilized with the present invention. It is desired to connect drives 62A and 62B with respective knife assemblies 58 in a manner that provides good power transmission, and smooth operation, and which reduces potentially damaging loading conditions exerted against the drives and connecting apparatus .

[ 0026 ] Referring also to FIGS. 6 and 7, drives 62A and 62B are connected in reciprocating driving relation to the respective knife assemblies 58 by knife heads 64, and a knife arm assemblies 66 constructed and operable according to the present invention. As shown in FIG. 6, each knife head 64 is an elongate member attached by an array of threaded fasteners to the associated knife assembly 58. Each knife arm assembly 66 includes an elongate knife arm 68 having a mounting end 70 that connects to an output element of the associated drive 62A or 62B, an opposite distal end 72 that connects to the associated knife head 64, and a pivot 74 disposed between ends 70 and 72 so as to allow only pivotal movement the knife arm, about an upstanding pivotal axis 76 through pivot 74.

[ 0027 ] As best shown in FIG. 7, mounting end 70 of each knife arm 68 includes a circular aperture 78 that contains a multiple race eccentric bearing arrangement 80, which is preferably a triple race eccentric bearing 82. Bearing 82 has an outer race 84 extending about a middle race 86, which extends about an inner race 88, with a outer bearing set 90 comprising a plurality of suitable bearing elements, e.g., balls, rollers or needles, disposed between and in contact with races 84 and 86, and an inner bearing set 92 between races 86 and 88. At least race 86 is eccentric, meaning that an outer bearing surface 94 thereof in contact with the outer bearing set 90 is eccentric to an inner bearing surface 96 in contact with bearing set 92. Outer race 84 is held, e.g., press fit, in aperture 78 and thus will move, or be moved, in fixed relation to the arm 68 in which it is located, and is retained by a suitable element such as a large internal snap ring receivable in a groove about the surface defining aperture 78 (deleted for clarity) . Inner race 88 is held, e.g., press fit, about an outer peripheral circumferential surface of a disk shaped shuttle element 98 of the associated drive 62A or 62B so as to rotate with shuttle element 98, and is similarly retained by an external snap ring or the like.

[ 0028 ] Because middle race 86 is eccentric as described above, shuttle element 98 is eccentric to aperture 78, and because the races are relatively rotatable, the orientation of the eccentricity within aperture 78 is variable. This and the use of two bearing sets with a middle race allow shuttle element 98 and knife arm 68 to relatively rotate, and to do so at different speeds. Arm 68 has a pivotal length PL measured between pivotal axis 76 and a center 100 of aperture 78, and center 100 will move along an arcuate path AP as arm 68 pivots about pivotal axis 76.

[ 0029 ] Shuttle element 98 is fixedly mounted

eccentrically on an output element of the drive 62A or 62B which is a pinion shaft 102 of a pinion gear 104 enmeshed with a fixed ring gear 106 of the drive 62A or 62B. Ring gear 106 has a pitch diameter about 4 times that of pinion gear 104. Pinion gear 104 is driven by the drive 62A or 62B so as to orbit around ring gear 106 in a direction Rl (clockwise as illustrated), and thus gear 104 will rotate counterclockwise as denoted by arrow R2. Because shuttle element 98 is fixed to pinion shaft 102, it too will rotate in the counterclockwise direction, as denoted by arrow R3. This arrangement, and the restraint in aperture 78, will result in reciprocating linear movement LM of shuttle element 98 along a linear path LP, which is the centerline of ring gear 104, while rotating in direction R3. The distance of the linear movement will be limited as determined by the geometry of the gear arrangement, mainly the diameter of ring gear 104.

[ 0030 ] The above described linear movement, in combination with the ability of arm 68 to only pivot about pivotal axis 76; the eccentricity of bearing 82; and ability of races 84, 86, and 88 to relatively rotate, results in the translation of the linear movement LM of shuttle 98 in the direction shown to pivotal movement PM of arm 68 also in the direction shown. When shuttle element 98 reaches the limit of its linear movement LM, it will automatically reverse direction (although rotational directions R1-R3 will remain the same), to also reverse the direction of pivotal movement PM. As a result, the drive 62A or 62B will reciprocatingly drive pivot arm 68, for

reciprocatingly moving the attached knife head 68 and associated knife assembly 58 sidewardly for performing the desired cutting action.

[ 0031 ] Here, it should be noted that the degree of eccentricity E of bearing 82 will be desirably a function of the distance between path AP and path LP, which changes continuously during the operation of the drive. Bearing 82 is configured to rotate as required to compensate for this distance such that binding is minimized and smooth operation occurs. The maximum value of eccentricity E will correspond at least substantially to the maximum distance or difference between paths AP and LP, as denoted by distance D. It should also be noted that drives 62A and 62B are preferably counter driven in opposite directions, such that the directions of rotation R1-R3 of drive 62A will be the opposite of those described above in regard to drive 62B and illustrated in FIG. 7. It can also be noted that at the end of its travel from the position shown in FIG. 7, knife arm assembly 66 attached to drive 62B will be essentially oriented as shown by knife arm assembly 66 attached to drive 62A as shown in FIG. 6. In this regard, it should be noted that although a triple race eccentric bearing is preferred, other multiple race eccentric bearing constructions that can compensate for the differences between the linear path of the drive and pivotal arcuate path of the drive knife arm can be used according to the invention.

[ 0032 ] As a result of the pivotal support of the knife arm assemblies relatively close to the sickle, and the drive and bearing arrangement described above, satisfactory power transmission and smooth operation are achieved, with reduced potentially damaging loading conditions exerted against the knife arm.

[ 0033 ] In light of all the foregoing, it should thus be apparent to those skilled in the art that there has been shown and described a novel pivoting knife arm assembly for connecting a sickle knife to a

reciprocating drive mechanism. However, it should also be apparent that, within the principles and scope of the invention, many changes are possible and contemplated, including in the details, materials, and arrangements of parts which have been described and illustrated to explain the nature of the invention. Thus, while the foregoing description and discussion addresses certain preferred embodiments or elements of the invention, it should further be understood that concepts of the invention, as based upon the foregoing description and discussion, may be readily incorporated into or employed in other embodiments and constructions without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown, and all changes, modifications, variations, and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is limited only by the claims which follow .

Claims

What is claimed is: 1. A knife arm assembly (66) for connecting a sickle knife (30) to an epicyclical drive mechanism (62A, 62B) , including a pivoting knife arm (68) having a mounting end ( 70 ) configured for connection to the epicyclical drive mechanism (62A, 62B) for reciprocating sideward movement therewith, a distal end (72) opposite the mounting end (70) configured for connection to the sickle knife (30) ;

characterized by the mounting end (70) of the knife arm (68) including a multiple race eccentric bearing arrangement (80) for connection to the epicyclic drive mechanism (62A, 62B) in a manner for translating linear movements of the epicyclic drive mechanism (62A, 62B) into arcuate movements of the knife arm (68) .

2. The knife arm assembly (66) of claim 1, wherein the multiple race eccentric bearing arrangement (80) comprises a triple race eccentric bearing (82) .

3. The knife arm assembly (62A, 62B) of claim 1, further characterized by the multiple race eccentric bearing arrangement ( 80 ) includes an inner race (88) mounted about a shuttle element (98) moved linearly by rotational and orbital movements of a pinion (102) relative to a ring (106) of the epicyclic drive

mechanism (62A, 62B) .

4. The knife arm assembly (66) of claim 1, wherein the bearing arrangement (80) has eccentricity substantially equal to a maximum distance between an arcuate path of the knife arm (68) and a path of linear movement of a shuttle element (98) of the epicyclic drive mechanism (62A, 62B) .

5. The knife arm assembly (66) of claim 1, wherein the epicyclic drive mechanism (62A, 62B) is incorporated in or below a floor (28) of a plant cutting machine (20), the knife arm (68) is mounted by a pivot (74) between the mounting end (70) and the distal end (72) for pivotal movement relative to the floor (28), and the multiple race eccentric bearing arrangement (80) is mounted about a linearly reciprocating shuttle element (98) of the epicyclic drive mechanism (62A, 62B) such that reciprocating linear movements of the shuttle element (98) will be translated into limited pivoting movements of the knife arm (68), and the distal end (72) of the knife arm (68) is connected to the sickle knife (30) along a forward edge (32) of the floor (28) such that the pivoting movements of the knife arm (68) will move the sickle knife (30) in a reciprocating side to side motion along the forward edge (32) .

6. A knife arm assembly connecting a sickle knife to an epicyclical drive mechanism, comprising a pivoting knife arm having a mounting end connected to a shuttle element of the epicyclical drive mechanism, a distal end opposite the mounting end, and a pivot at a location between the mounting end and the distal end, the mounting end being connected to the shuttle element with a multiple race eccentric bearing arrangement .

7. The knife arm assembly of claim 6, wherein the multiple race eccentric bearing arrangement comprises a triple race eccentric bearing carried in an aperture in the mounting end of the knife arm, the shuttle element is connected to an eccentric pinion of the epicyclic drive mechanism, such that when the eccentric output element is rotated the shuttle element will be moved in a generally linear reciprocating motion and the eccentric bearing will relatively rotate to translate the linear reciprocating motion of the shuttle element to a limited reciprocating arcuate motion of the mounting end of the knife arm to reciprocatingly pivot the knife arm.

8. The knife arm assembly of claim 6, wherein the epicyclic drive mechanism is incorporated in or below a floor of a plant cutting machine, the pivot of the knife arm is mounted for pivotal movement of the knife arm relative to the floor, the sickle knife is disposed along a forward edge of the floor, and the eccentric bearing arrangement is mounted about the shuttle element of the epicyclic drive mechanism below the floor, and reciprocating linear movements of the shuttle element will translate into limited pivoting movements of the knife arm to move the sickle knife in a reciprocating manner along the forward edge.

9. The knife arm assembly of claim 6, wherein the bearing arrangement has eccentricity substantially equal to a maximum distance between a predetermined arcuate path of pivotal movement of the mounting end of the knife arm and a predetermined path of linear movement of the shuttle element.

10. A knife arm assembly connecting a sickle knife to an epicyclical drive mechanism, comprising a pivoting knife arm having a mounting end connected to a shuttle element connected to an eccentric pinion of the epicyclical drive mechanism, a distal end opposite the mounting end, and a pivot at a location between the mounting end and the distal end, the mounting end being connected to the shuttle element by a triple race eccentric bearing arrangement configured and operable in cooperation with the shuttle element for translating reciprocating linear movements of the shuttle element to limited reciprocating pivoting movements of the knife arm.

11. The knife arm assembly of claim 10, wherein the epicyclic drive mechanism is incorporated in or below a floor of a plant cutting machine, the pivot of the knife arm is mounted for pivotal movement of the knife arm relative to the floor, the sickle knife is disposed along a forward edge of the floor, and the triple race eccentric bearing arrangement is mounted about the shuttle element of the epicyclic drive mechanism below the floor such that the limited pivoting movements of the knife arm will move the sickle knife in a reciprocating manner along the forward edge.

12. The knife arm assembly of claim 10, wherein the bearing arrangement has eccentricity substantially equal to a difference between an arcuate path of the pivotal movement of the mounting end of the knife arm and a path of the linear movement of the shuttle element.