Hybrid disc cutting system having a knife mount for an agricultural vehicle

An agricultural vehicle includes a chassis and a header carried by the chassis. The header includes a cutterbar with at least one cutting unit. The at least one cutting unit includes a rotary driver; a rotatable disc coupled to the rotary driver; at least one knife mount coupled to a disc surface of the rotatable disc and including a locking portion biased toward the disc surface; and a knife locked in at least one direction by the locking portion, the knife defining at least one cutting edge.

BACKGROUND

Agricultural vehicles such as mowers, combine harvesters, windrowers, and forage harvesters, are equipped with one or more cutting elements to sever crops and other plant material in a field. Many different styles of cutting elements exist, depending on the application and desired cut characteristics. Mowers for cutting hay, for example, may be equipped with disc-type cutting elements that rotate to cut hay as the mower travels across the field. Alternatively, the mower may be equipped with sickle-type cutting elements that reciprocate to cut crop material as the mower travels across a field.

SUMMARY

The present disclosure relates to a header for an agricultural vehicle with a knife mount having a locking portion biased toward a disc surface of a rotatable disc to lock a knife.

In some exemplary embodiments disclosed herein, an agricultural vehicle, includes a chassis and a header carried by the chassis. The header includes a cutterbar with at least one cutting unit. The at least one cutting unit includes a rotary driver; a rotatable disc coupled to the rotary driver; at least one knife mount coupled to a disc surface of the rotatable disc and including a locking portion biased toward the disc surface; and a knife locked in at least one direction by the locking portion, the knife defining at least one cutting edge.

In some exemplary embodiments disclosed herein, a header for an agricultural vehicle includes: a header frame; a rotary driver carried by the header frame; a rotatable disc coupled to the rotary driver; and at least one knife mount coupled to a disc surface of the rotatable disc and having a locking portion biased toward the disc surface to lock a knife in at least one direction.

In some exemplary embodiments disclosed herein, a method of mounting a knife in a header for an agricultural vehicle is provided. The header includes a rotatable disc and a knife mount coupled to the rotatable disc. The method includes: forcing a locking portion of the knife mount away from a disc surface of the rotatable disc, the locking portion being biased toward the disc surface; placing the knife adjacent to the disc surface; and releasing the locking portion such that the locking portion travels toward the disc surface and locks the knife in at least one direction.

One possible benefit that may be realized by exemplary embodiments disclosed herein is the knife mount allows a knife to be quickly and easily installed or, if the knife dulls or breaks, replaced.

Another possible benefit that may be realized by exemplary embodiments disclosed herein is the knife may be pivotably locked in a knife slot so the knife does not pivot during cutting, which can improve cut quality.

DETAILED DESCRIPTION

Various terms relating to the methods and other aspects of the present disclosure are used throughout the specification and claims. Such terms are to be given their ordinary meaning in the art unless otherwise indicated. Other specifically defined terms are to be construed in a manner consistent with the definition provided herein.

The term “plurality” as used herein is defined as any amount or number greater or more than 1. In some embodiments, the term “plurality” means 2, 3, 4, 5, 6 or more.

The terms “left” and “right” are used herein as a matter of mere convenience, and are determined by standing at the rear of the machine facing in its normal direction of travel. Likewise, “forward” and “rearward” are determined by the normal direction of travel. “Upward” and “downward” orientations are relative to the ground or operating surface as are any references to “horizontal” or “vertical” planes or axes.

The terms “crops” and “crop material” are used herein to refer to any type of plant and/or vegetation that is intentionally planted for collection. Exemplary crops and crop material may include hay, wheat, and corn, but it should be appreciated that the embodiments disclosed herein are not limited to applications for collecting crops and crop material. Embodiments disclosed herein may be used, for example, to mow a field and sever other types of plant material such as grass, various varieties of weeds, etc.

The term “agricultural vehicle” is used herein to refer to an assembly of various elements that work in conjunction to travel and perform various tasks related to agriculture, such as removing crops, crop material, or other plant material from a field. Exemplary agricultural vehicles include, but are not limited to, vehicles that are commonly referred to as mowers, windrowers, spreaders, windrow inverters, and combine harvesters.

Many of the fastening, connection, processes and other components utilized in this disclosure are widely known and used in the field of the disclosure described, and their exact nature or type is not necessary for an understanding and use of the disclosure by a person skilled in the art, and they will not therefore be discussed in significant detail. Furthermore, the various components shown or described herein for any specific application of this disclosure can be varied and the practice of a specific application of any element may already be widely known or used in the art by persons skilled in the art and each will likewise not therefore be discussed in significant detail.

Referring now to the drawings and particularly toFIG. 1, an exemplary embodiment of a self-propelled agricultural vehicle100including a tractor110carrying a forwardly disposed header120is illustrated. While the agricultural vehicle100is illustrated in the form of a self-propelled vehicle, in some embodiments the header120is included in a vehicle that is pulled or otherwise carried by, for example, a user or another vehicle. Such agricultural vehicles are well-known in the art for offering a way to sever crops or other plants. The header120includes a cutterbar130disposed adjacent the forward end of the header120to sever standings crop or other plants from the ground. The cutterbar130is carried by a header frame140that connects to a chassis150of the tractor110to allow the tractor110to push the header120across terrain. While the header120is illustrated as being pushed by the tractor110, it should be appreciated that the header120operates similarly when pulled across terrain.

Referring now toFIG. 2, an exemplary embodiment of the cutterbar130is illustrated that includes a plurality of cutting units, with three cutting units210A,210B,210C illustrated. It should be appreciated that while three cutting units210A,210B,210C are illustrated, fewer than three cutting units, i.e., one or two cutting units, or more than three cutting units may be incorporated in the cutterbar130. In some embodiments, the cutting units210A,210B,210C are positioned side-by-side across a width of the header frame140, and therefore the header120, to sever crops or other plant material across the width of the header120. Each of the cutting units210A,210B,210C includes a respective rotatable disc220A,220B,220C that can rotate about a respective axis of rotation AA, AB, AC when driven by one or more coupled rotary drivers, illustrated as three rotary drivers230A,230B,230C. In some embodiments, the discs220A,220B,220C have a rounded shape, e.g., a circular shape or an ellipsoid shape. While each of the rotatable discs220A,220B,220C is illustrated as being coupled to a respective rotary driver230A,230B,230C, in some embodiments multiple discs may be rotatably driven by a single rotary driver. In some embodiments, the respective axes of rotation AA, AB, AC are aligned with one another on an alignment axis A spanning the width of the header frame140, with each axis AA, AB, AC extending generally vertically relative to the ground.

To cut crop material, and referring now toFIGS. 3 and 4as well, at least one of the rotatable discs220A,220B,220C carries one or more knives240A,240B,240C during rotation. In some embodiments, each of the discs220A,220B,220C carries at least two knives240A,240B,240C that are equally spaced apart from adjacent knives about the respective axis of rotation AA, AB, AC. Each of the knives240A,240B,240C has at least one cutting edge241A,242A,241B,242B,241C,242C to sever crops, crop material, or other plant material during rotation of the discs220A,220B,220C. In some embodiments, each of the knives240A,240B,240C has two cutting edges241A,242A,241B,242B,241C,242C, as illustrated, to extend the usable life of the knives240A,240B,240C, which is described further herein.

Referring specifically now toFIG. 3, an exemplary embodiment of a knife mount350for mounting a knife to the header120is illustrated. The knife mount350is coupled to a disc surface321of a disc, such as the disc220A, so the disc220A carries the knife mount350as the disc220A rotates about its axis of rotation AA. It should be appreciated that while a single knife mount350is illustrated inFIG. 3, some or all of the rotatable discs220A,220B,220C may have one or more knife mounts350coupled thereto for mounting knives240A,240B,240C to the rotatable discs220A,220B,220C. For example, in some embodiments one or more of the discs220A,220B,220C will have two or more knife mounts350for mounting two or more knives240A,240B,240C to the disc(s)220A,220B,220C. The knife mount350includes a locking portion351that is biased toward the disc surface321to lock a knife, such as the knife240A, in at least one direction. As illustrated inFIG. 3, for example, the locking portion351may lock the knife240A in a pull-out direction, signified by arrow D, that extends radially relative to the axis of rotation AA so the knife240A is not pulled away from the disc220A while moving. In some embodiments, the locking portion351directly compresses the knife240A against the disc surface321to lock the knife240A. It should be appreciated that the knife240A does not need to be compressed against the disc surface321to lock, as will be described further herein.

In some embodiments, the locking portion351is coupled to the disc surface321, which may be a bottom surface of the disc220A, by a deflectable portion352that is mounted to the disc surface321and connected to the locking portion351. It should be appreciated that the locking portion351may be mounted to a top surface322of the disc220A, rather than the bottom surface321. In some embodiments, the deflectable portion352includes a mounting portion353that is rigidly mounted to the disc surface321and an elastic portion354that connects to the locking portion351and comprises, for example, spring steel or another elastic material that is biased toward the disc surface321. In some embodiments, the elastic portion354is integrally formed with the locking portion351and the mounting portion353and, as illustrated in theFIG. 4, has a reduced width compared to the mounting portion353.

In some embodiments, and referring again toFIGS. 3-4, the locking portion351includes a locking projection355that is sized to fit within a locking opening421formed in the knife240A to lock the knife240A in at least one direction. The locking projection355may have a round or other shape to define a pivoting axis, illustrated as axis PA inFIG. 3, that can allow pivoting of the knife240A about the pivoting axis PA if the knife240A is unconstrained. In some embodiments, the knife240A may pivot up to 360° about the pivoting axis PA defined by the locking projection355.

To protect the knives240A,240B,240C and other components of the header120during operation, and referring specifically toFIGS. 2-3, each cutting unit210A,210B,210C may include a guard assembly260A,260B,260C held adjacent to the respective cutting disc220A,220B,220C of the cutting unit210A,210B,210C. Each guard assembly260A,260B,260C may include a plurality of extensions261A,261B,261C that extend from a base portion262, which may be connected to a bottom of the cutterbar130. Each guard assembly260A,260B,260C may include a bottom portion362and a top portion363connected to the bottom portion362to define a knife passage364therebetween. The knife passage364is sized, shaped, and oriented such that the knives, such as knife240A, are allowed to pass through the knife passage364during a full rotation of the disc220A,220B,220C carrying the knives. To allow passage of the knives240A,240B,240C through the knife passage364, the knife passage364of each guard assembly260A,260B,260C may be formed with a passage height PH that is greater than a knife thickness KT of the knives, such as knife240A. In some embodiments, the passage height PH is between about 1.5 to about 2.0 times greater than the knife thickness KT of the knives that rotate through the knife passage. For example, in some embodiments the knife thickness KT of the knife240A may be between about 1.5 mm and about 3.0 mm and the passage height PH may be between about 2.3 mm and about 6.0 mm. It should be appreciated that the previously described knife thickness and passage height values are exemplary only and may be modified depending on the desired cutting behavior of the knives.

During operation, each of the rotatable discs220A,220B,220C may rotate about its respective axis of rotation AA, AB, AC and carry the respective knives240A,240B,240C about the axis of rotation AA, AB, AC. As the knives240A,240B,240C rotate, one of the cutting edges of each knife, such as cutting edges241A,241B,241C, can engage and sever crop or other plant material. In some embodiments, the knives240A,240B,240C are allowed to pivot about their respective pivoting axes PA, which may extend generally vertical relative to the ground.

When the cutting edges241A,241B,241C initially engage material, which may be one or more plant stalks, the material will tend to deflect, i.e., bend, responsively. This deflection is more pronounced when the cut height is increased due to engagement between the cutting edges241A,241B,241C and the plant material taking place further from the ground, where the plant material is supported. In some cases, the material engaged by the cutting edges241A,241B,241C is also thinner, and thus more prone to bending, at greater heights from the ground. If the material being cut significantly bends when engaged by the cutting edges241A,241B,241C, the cutting edges241A,241B,241C may not cut the material evenly or cleanly.

As should be appreciated fromFIG. 2, crop slots264may be defined between opposing ledger surfaces263A,263B of each of the extensions261A,261B,261C along the width of the cutterbar130. As the vehicle100travels through a field to sever crops or other plant material, standing plants tend to travel into and accumulate in the crop slots264. The cutting edges241A,241B,241C, which travel through a portion of the crop slots264, engage accumulated material in the crop slots264as the knives240A,240B,240C rotate with the discs220A,220B,220C to sever the material. When the cutting edges241A,241B,241C engage the material during rotation of the knives240A,240B,240C, the material tends to bend in a direction of knife rotation, signified by arrow R. The ledger surface that is downstream from the material in the direction of knife rotation R, which may be the ledger surface263A, counteracts the tendency of the material to bend by supporting the material during contact. The ledger surface263A supporting the material allows the cutting edges241A,241B,241C to cleanly and evenly cut through the material for a consistent cut. In this sense, the ledger surfaces263A,263B of the extensions261A,261B,261C promote scissor-like cutting action by the knives240A,240B,240C, similar to a reciprocating sickle-type cutter, as the knives240A,240B,240C rotate.

In some embodiments, the extensions261A,261B,261C, and thus the ledger surfaces263A,263B, comprise a metal, such as steel, that may be hardened by induction hardening, or otherwise, to reduce the effects of abrasive wear and increase the effective lifespan of the extensions261A,261B,261C. In some embodiments, one or more of the ledger surfaces263A,263B may be coated with a high-strength material, such as tungsten carbide. To further promote scissor-like cutting action by the rotating knives240A,240B,240C, one or more of the ledger surfaces263A,263B may be modified. In some embodiments, one or more of the ledger surfaces263A,263B are sharpened, i.e., beveled, or otherwise angled. In some embodiments, one or more of the ledger surfaces263A,263B is formed with serrations, which may be in addition to or an alternative to sharpening the ledger surface(s)263A,263B.

In known rotary-style cutters, the carried knives are generally free to pivot about their mounting points as they rotate with their respective discs. Due to the relatively high rotational speed of the knives and low height from the ground, such known rotary-style cutters experience little, if any, performance loss due to this pivoting because the knives cut through material, which is spread across the width of the cutterbar, relatively easily.

In a header including extensions with ledger surfaces for supporting crop or other plant material during cutting, such as exemplary embodiments of the header120disclosed herein, allowing the knives to freely pivot about their pivoting axes may detrimentally affect cutting performance. Particularly, as crop or other plant material accumulates in the crop slots264, there is a relatively high density of material that is severed by each knife240A,240B,240C during a full rotation of its respective disc220A,220B,220C. The relatively high density of material substantially increases the resistance that the knives240A,240B,240C experience during cutting, increasing the chance that one or more of the knives240A,240B,240C will excessively pivot out of a position to engage and cut through the material. The knives240A,240B,240C freely pivoting also increases the risk that the knives240A,240B,240C pivot into a position where the knives240A,240B,240C may contact one or more of the extensions261A,261B,261C during operation.

In some embodiments, and referring again toFIG. 4, a pair of knife stops471A,471B are mounted to the disc surface321to define a knife slot472therebetween in order to minimize pivoting of the knives240A,240B,240C. The locking portion351of the knife mount350may be biased toward the disc surface321such that the locking portion351at least partially resides in the knife slot472normally. A knife, such as knife240A, may be held in the knife slot472between the knife stops471A,471B and locked by the locking portion351. The locking portion351can prevent the knife240A from being pulled in the pull-out direction D while the knife stops471A,471B substantially prevent the knife240A from pivoting about its pivoting axis PA, which may be a vertical axis defined by the locking projection355, or otherwise moving in a direction parallel to the disc surface321. As used herein, the knife240A is “substantially prevented” from pivoting in the sense that the knife240A is free to pivot by no more than 1° clockwise or counterclockwise relative to its pivoting axis PA. The knife slot472may define a knife slot width KSW that is similar to a knife width KW of the knife240A to limit the ability of the knife240A to move during operation. In this respect, the disc surface321, the locking portion351, and the knife stops471A,471B can work in conjunction to rigidly lock the knife240A to the disc220A during rotation of the disc220A so the knife240A minimally translates or pivots, if at all, relative to the disc surface321during rotation. Thus, the knife stops471A,471B can allow the knives240A,240B,240C to be pivotally locked as the discs220A,220B,220C rotate to maintain the knives240A,240B,240C in a generally fixed position relative to the guard assemblies260A,260B,260C.

In some embodiments, and referring now toFIG. 5, a support surface580may be connected to one or both of the knife stops471A,471B to act as a vertical support for a knife, such as the knife240A. The support surface580may also have a back surface581connected thereto that extends toward the disc surface321to act as a backstop, which will be described further herein. The support surface580defines a clearance C, relative to the disc surface321, that may be slightly greater than the knife thickness KT of the knife240A to limit the distance between the knife240A and the disc surface321, and thus the vertical tilting freedom of the knife240A. To allow locking of the knife240A by the locking portion351, the support surface580may be formed with a through-hole that aligns with the locking opening421of the knife240A when the knife240A is properly oriented and allows at least a portion of the locking portion351, such as the locking projection355, to extend through both the through-hole and the locking opening421to lock the knife240A.

Referring now toFIG. 6, an exemplary embodiment of a method600for mounting a knife, such as the knife240A, in a header, such as the header120, is illustrated. The header120includes a rotatable disc, such as the rotatable disc220A, and a knife mount, such as the knife mount350, coupled to the rotatable disc220A. The method600includes forcing601a locking portion351of the knife mount350away from a disc surface321of the rotatable disc220A. The locking portion351is biased toward the disc surface321and thus resists being forced away from the disc surface321. In some embodiments, the locking portion351may be forced away from the disc surface321by a user grasping and pulling the locking portion351away from the disc surface321or by a user using a tool to pry open the locking portion351. In some embodiments, the locking portion351may be angled at its front such that pushing a surface, such as a portion of the knife240A, against the front of the locking portion351forces the locking portion351away from the disc surface321. The locking portion351may be biased toward the disc surface321by a deflectable portion352, as previously described.

The method600further includes placing602the knife240A adjacent to the disc surface321and releasing603the locking portion351such that the locking portion351travels toward the disc surface321and locks the knife240A in at least one direction, such as a pull-out direction D. In some embodiments, placing602the knife240A includes positioning the knife240A in a knife slot472defined between a pair of knife stops471A,471B that are mounted to the disc surface321. The knife240A may be supported on its bottom by a support surface580and pushed into the knife slot472until the knife240A contacts a back surface581connected to the support surface580, which prevents further advancement of the knife240A in the knife slot472. The knife stops471A,471B substantially prevent pivoting of the knife240A about a vertical pivoting axis PA, relative to the ground, when the knife240A is positioned in the knife slot472, as previously described. It should be appreciated that, after mounting the knife240A, the knife240A may be removed by forcing601the locking portion351away from the disc surface321and pulling the knife240A away from the disc surface321. The knife240A may then be flipped so different cutting edges, such as cutting edges242A,242B,242C, are utilized during operation or, alternatively, the knife240A may be replaced by a new knife.