System for cutterbar support having torsion device with elastic material and load limiting apparatus

A system for supporting a cutterbar of a crop harvesting header includes a first arm pivotably secured to the header. The first arm includes a first portion configured to support the cutterbar. The first arm includes a second portion including a torsion device having a mass of elastic material connected to an adjustment assembly. The second portion is configured to be pivotably rotatable about an axis by the adjustment assembly to selectably increase or decrease a force appliable to the first portion in order to raise or lower the first portion with respect to the header. A load limiting apparatus limits an amount of torsional force that is applied to the mass of elastic material by pivotable rotation of the second portion about the axis.

FIELD OF THE INVENTION

The present invention relates generally to crop harvesting headers for use with crop harvesting devices. It relates more particularly to a system for supporting a cutterbar of a crop harvesting header.

BACKGROUND OF THE INVENTION

The cutting assemblies of the known large headers of plant-cutting machines (e.g., combine, windrower) are typically driven by an oscillating drive, which can include, but is not limited to, an eccentric shaft on a rotating hub, a wobble drive, or a similar well-known commercially-available device. A cutting assembly is typically supported by a flexible cutterbar that spans the width of the opening of the crop harvesting header. The cutterbar is typically supported by arms that extend transverse to the cutterbar. Unfortunately, the weight of the cutting assembly is not uniformly distributed across the cutting width of the harvesting header, possibly causing bowing of the cutterbar, and the cutting assembly, resulting in uneven cutting height of the plant, as well as other undesirable results.

In response, Applicant has made great strides in this area through the use of a torsion device having elastic material, such as disclosed in U.S. Pat. No. 8,051,633, titled Cutterbar Adjustment Support For A Harvesting Header. However, further improvements are needed, such as maintaining performance while extending the service life of the elastic material.

What is needed is a system that provides substantially uniform support along the length of the cutting assembly by permitting selective adjustment of the forces the arms provide to the cutterbar, while maintaining performance and extending the service life of the system.

SUMMARY OF THE INVENTION

The present invention relates to a system for supporting a cutterbar of a crop harvesting header including a first arm pivotably secured to the header. The first arm includes a first portion configured to support the cutterbar, the first arm including a second portion including a torsion device having a mass of elastic material connected to an adjustment assembly. The second portion is configured to be pivotably rotatable about an axis by the adjustment assembly to selectably increase or decrease a force appliable to the first portion in order to raise or lower the first portion with respect to the header. A load limiting apparatus is operatively connected to the torsion device for limiting an amount of torsional force that is applied to the mass of elastic material by pivotable rotation of the second portion about the axis. The adjustment assembly includes a second arm interconnecting the torsion device and an adjustment device having a first segment, the adjustment device configured to movably receive a connecting adjustment device. The first segment of the adjustment device is configured to follow a predetermined path in a first direction with respect to the axis in response to movement of the adjustment device in a first direction with respect to the first adjustment device. The first segment of the adjustment device is configured to follow a predetermined path in a second direction with respect to the axis in response to movement of the connecting adjustment device in a second direction opposite the first direction with respect to the adjustment device.

The present invention further relates to a system for supporting a cutterbar of a crop harvesting header including a first arm pivotably secured to the header. The first arm includes a first portion configured to support the cutterbar, the first arm including a second portion including a torsion device having a mass of elastic material connected to an adjustment assembly, the second portion configured to be pivotably rotatable about an axis by the adjustment assembly to selectably increase or decrease a force appliable to the first portion in order to raise or lower the first portion with respect to the header. A load limiting apparatus is operatively connected to and contained inside the torsion device for limiting an amount of torsional force that is applied to the mass of elastic material by pivotable rotation of the second portion about the axis. The adjustment assembly includes a second arm interconnecting the torsion device and an adjustment device having a first segment, the adjustment device configured to movably receive a connecting adjustment device. The first segment of the adjustment device is configured to follow a predetermined path in a first direction with respect to the axis in response to movement of the adjustment device in a first direction with respect to the first adjustment device. The first segment of the adjustment device is configured to follow a predetermined path in a second direction with respect to the axis in response to movement of the connecting adjustment device in a second direction opposite the first direction with respect to the adjustment device.

An advantage of the present invention is a system applying a substantially uniform support force for the cutterbar, while maintaining performance and extending the service life of the system.

DETAILED DESCRIPTION OF THE INVENTION

A combine20, which is a well-known agricultural cutting and harvesting machine, is shown inFIG. 1. Combine20includes a header22, which is configured to cut or sever crops, including (without limitation) small grains (e.g., wheat, soybeans), and to induct the cut or severed crops into a feeder26. Both functions can be performed as combine20moves forward over a crop field.

Header22is attached to a forward end24of combine20and includes a pan or floor28that is supported in desired proximity to the surface of a crop field. Header22includes an elongated sidewardly extending sickle30along a forward edge portion32(seeFIG. 2) of floor28. A cutter or sickle30is configured to cut or sever crops, in preparation for induction into a feeder26. Additionally, header22may include an elongate, sidewardly extending reel34disposed above sickle30. Reel34is rotatable in a direction suitable for facilitating the induction of cut or severed crops into feeder26. Header22further includes an elongate, rotatable auger36, which extends in close proximity to a top surface38of floor28and has helical flights therearound. Auger36is configured to cooperate with reel34in conveying cut or severed crops to feeder26, which is configured to convey the cut or severed crops into combine20for threshing and cleaning. Alternatively, instead of rotatable auger36, header22may include a draper header or other crop harvesting/gathering header.

Sickle30extends along a forward edge40of floor28, and generally is bounded by a first side edge42and an opposing second side edge44, both of floor28. Sickle30is supported by a cutterbar45(seeFIG. 3) which is likewise supported by a first portion46of an elongated member or first arm48that will be discussed in further detail below. During operation, sickle30reciprocates rapidly to effect a cutting or severing action that cuts or severs plant stems, stalks or other material present between the blades of the sickle. As denoted by arrow50, the sickle blades can reciprocate sideways.

As shown inFIGS. 3-5, a C-bracket or second portion52of member or first arm48is pivotably secured to header22about an axis56by a rod58having a non-circular periphery, such as a hexagonal periphery. Rod58further extends through openings formed in plates94,96that are secured to header22and laterally surround second portion52. In other words, rod58extends through each of plates94,96, apertures98formed in second portion52and a torsion device90forming part of a cutterbar support system300. That is, fasteners104are first inserted through respective aligned openings106in second portion52and apertures formed in torsion device90to secure the torsion device to the second portion (assembling the exploded view ofFIG. 4). Once the torsion device90is assembled to the second portion52, aperture98of second portion52is positioned between and aligned with openings (not shown) formed in plates94,96and their respective bushings100, rod58may then be inserted through plates94,96, bushings100, second portion52and torsion device90(seeFIG. 5). After insertion of rod58, the outer periphery of rod58and an inside surface80(seeFIG. 4) of torsion device90are placed in a non-rotating relationship, i.e., they become mated surfaces. Finally, opening108(seeFIG. 8) of second arm102is aligned and slid over rod58, with opening108and rod58defining mating surfaces and fastener110installed in rod58to secure rod58in its installed position. At this point, in response to first arm48being urged into rotational movement about axis56, by virtue of the mating surfaces between rod58and inside surface80of torsion device90and between opening108of second arm102and rod58, rod58and second arm102would each be urged into rotation about axis56.

Other operating details may be contained in U.S. Pat. No. 8,051,633, titled Cutterbar Adjustment Support For A Harvesting Header, which is incorporated by reference in its entirety.

FIGS. 6-7show a side view and a cross section, respectively, of torsion device90. Torsion device90includes a housing60includes a plurality of lobes64having corresponding apertures62formed in the lobes, permitting the housing to be secured to other structure, such as plate94,96(FIG. 5) by mechanical fasteners104extending through the other structure and apertures62. Housing60includes an inside surface66that may include a tapered surface82, such as shown inFIG. 7. A member68, which includes an inside surface70and an outside surface72, is comprised of a resilient material mass that is inserted inside of housing60. In one embodiment, member68is composed of a non-metal, such as a rubber material. Inside surface66of housing60is configured to receive outside surface72of member68and define a substantially non-rotational contact therebetween. Stated another way, subsequent to insertion of member68inside of housing60, in response to a rotational movement86applied in a clockwise direction about axis56to housing60and an opposed rotational movement88applied in a counter clockwise direction about axis56to member68, inside surface66and outside surface72should not rotatably move with respect to each other. Such non-rotational contact may be established by application of adhesives, interference-fit (due to the periphery of inside surface66being larger than the periphery of outside surface72), mating surface features, such as splines, or the like.

As further shown inFIGS. 6-7, inside surface70of member68is configured to receive a sleeve76having an outside surface78and inside surface80. Housing60and sleeve76are composed of substantially rigid materials, such as metals. When member68and sleeve76are assembled together, inside surface70of the member and outside surface78of the sleeve define a substantially non-rotational contact therebetween, as discussed above. Inside surface80of sleeve76defines a geometric shape that is configured to receive an object, such as a shaft, in a substantially non-rotational contact. As shown inFIG. 6, inside surface80defines a hexagonal profile, although other profiles may be used. In a further embodiment, sleeve76may not be required, if inside surface70of member68defines a hexagonal profile, for example.

As shown inFIG. 7, member68includes recessed ends74. In one embodiment, recessed ends74may be created during the normal cooling process of member68, which may be composed of rubber or another suitable resilient material. That is, member68may be heated to a liquid state and then installed while in the liquid state, such as by pouring or injection molding, into housing60between inside surface70and outside surface72. During cooling, member68bonds to each of inside surface70and outside surface72. In an alternate embodiment, member68may be press-fit between inside surface70and outside surface72. In yet another embodiment, member68may be secured between inside surface70and outside surface72by use of an adhesive.

In summary, by virtue of the collective substantially non-rotational contacts established between corresponding surfaces of housing60, member68, sleeve76and a shaft received by the sleeve, in response to a rotational movement86about axis56applied by a shaft58, and a counter rotational movement88about axis56applied to oppose the rotational movement applied by the shaft, the member68is subjected to a torsional force, which is the basis for the equalizing torsional force provided by the support system.

Referring toFIGS. 3,5, and8-10, adjustment assembly92is now discussed. Adjustment assembly92includes second arm102having an aperture114located distantly from opening108that is pivotably connected, such as by fastener118to a first segment116of a first adjustment device112. In one embodiment, first segment116includes an eyelet (seeFIG. 3) formed in first adjustment device112, with the first adjustment device being a threaded rod. First adjustment device112is movably connected with a second adjustment device120. In one embodiment, the second adjustment device is a threaded nut configured to mate with the first adjustment device. After assembly, second adjustment device120is placed in abutting contact with the portion of header22. In one embodiment, the portion of header22is a bracket122, in which the abutting contact occurs between a portion of the exterior surface of second adjustment device120and at least a portion of a surface of an aperture124. In one embodiment, at least a portion of second adjustment device120includes a tapered surface126. In one embodiment, tapered surface126is curved. Tapered surface126is configured to increase the amount of surface area of the abutting contact between the surface of aperture124of bracket122, thereby reducing the amount of resistance required to move second adjustment device120with respect to bracket122. In a further embodiment, the abutting contact surfaces between tapered surface126and aperture124define conformal surfaces. That is, the abutting contact surfaces substantially conform with each other to maximize the amount of shared surface area to reduce the amount of resistance between the contact surfaces in response to a given force directed perpendicular to the contact surfaces. To urge rotational movement of second adjustment device120with respect to bracket122, a region128is provided to receive a tool, such as a wrench, or in another embodiment, the region defines an opening to receive a lever arm.

By virtue of adjustment assembly92, such as shown in theFIG. 3, first portion46of first arm48can be selectively raised or lowered. In other words, in response to a rotational movement in a first rotational direction or a first tendency of second adjustment device120, second adjustment device120is placed in abutting contact with bracket122such that the length of first adjustment device112between bracket122and first segment or eyelet116is increased, urging second arm102to rotate about axis56. When sufficient rotation of second arm102has occurred, and has applied a sufficient torsional force to torsion device90, first portion46of first arm48is raised with respect to header22subject to the header encountering a stop132extending from the first arm. Stop132may also be employed to limit the lowest position of first portion46with respect to header22. Conversely, in response to a rotational movement in a second rotational direction or a second tendency of second adjustment device120, second adjustment device120is placed in abutting contact with bracket122such that the length of first adjustment device112between bracket122and first segment or eyelet116is decreased, urging second arm102to rotate about axis56. When sufficient rotation of second arm102has occurred, and has applied a sufficient torsional force to torsion device90, first portion46of first arm48is lowered with respect to header22. Depending upon the application, multiple first arms48may be used to provide support for the cutterbar.

It is also to be understood that while adjustment assembly92may be used to selectively raise or lower first portion46of first arm48, the same techniques and interaction between components previously discussed may also be used to selectively increase or decrease a force that may be applied to first portion46of first arm48in order to raise or lower first portion with respect to header22. That is, for example, stop132extending from first arm48may be in abutting contact (not shown) with header22such that first arm48cannot be further lowered with respect to header22. For purposes of discussion only, and not intending to be limiting, a force of X pounds may be required to raise first portion46with respect to header22. By moving second adjustment device120in a first tendency, without raising/lowering first portion46with respect to header22, a force of Y pounds (Y<X) may then be required to raise first portion46with respect to header22. Conversely, by moving second adjustment device120in a second tendency, instead of a first tendency, also without raising/lowering first portion46with respect to header22, a force of Z pounds (Z>X) may then be required to raise first portion46with respect to header22. In other words, for purposes of comparison only, X, Y and Z correspond to magnitudes of forces each being applied in the same direction with respect to the header in order to raise or lower the header. In one embodiment, the magnitude of force required to raise or lower the first portion of each first arm would be the same.

By virtue of the arrangement of adjustment assembly92, due to first adjustment device112being located between second arm102and second adjustment device120, during operation of the adjustment assembly, first segment or eyelet116of first adjustment device112is configured to follow a predetermined path with respect to axis56. In the exemplary embodiment as shown inFIG. 10, a predetermined path of first segment or eyelet116corresponds to the radius defined by axis56and aperture114of second arm102. As a result of this arrangement, over the operating range of adjustment assembly92, bending forces that could otherwise be applied to first adjustment device and cause damage to the first adjustment device are virtually eliminated. That is, by virtue of the movable abutting contact between tapered surface126and the surface of aperture124of bracket122over the operating range of angular movement of second arm102about axis56, including different positions as shown in respectiveFIGS. 8 and 9and as shown inFIG. 10by a centerline representation130of first adjustment device112, first adjustment device112can pivot with virtually no lateral forces associated with the abutting contact.

Referring toFIGS. 11 and 12, alternative embodiments of second adjustment device220,320are shown, in which opposed tapered surfaces are combined into a single component. For second adjustment device220, the larger ends of the tapered surfaces face each other, which would normally require removal of the second adjustment device from the mating first adjustment device if the rotational direction or tendency were to be reverse. For second adjustment device320, the smaller ends of the tapered surfaces face each other, which should not require removal of the second adjustment device from the mating first adjustment device if the rotational direction or tendency were to be reversed. However, the aperture124of bracket122would need to be “opened up” to form a slot in order to receive second adjustment device320. Adjustment regions128configured to receive tools could be located as shown or in other locations.

As will be shown in an exemplary embodiment below, a load limiting apparatus, such as load limiting apparatus394(FIG. 14) may be utilized with a cutterbar support system. The load limiting apparatus is provided in order to limit the extent of torsional flexure of elastic or resilient member68operatively connected to torsion device90as a result of forces generated by adjustment assembly92in order to raise or lower cutterbar45as previously discussed.FIG. 3shows cutterbar45in a raised position178versus a lowered position180. Raised position178corresponds to stop132being positioned at an upper extent of a slot184formed in bracket182of frame22. Lowered position180corresponds to stop132being positioned at a lower extent of slot184formed in bracket182of frame22. The different positions may be used for different kinds of crops. For example, raised position178is generally the preferred position for harvesting wheat, while lowered position180is generally the preferred position for harvesting soybeans. Prior to utilization of a load limiting apparatus, such as load limiting apparatus394, which will be discussed in further detail below, in order to raise cutterbar45from its lowered position180to raised position178, it had been required to subject elastic or resilient member68of torsion device90to the entire torsional load generated by the downward force applied by first adjustment device112and second arm102about axis56. This extended load resulted in a reduction in performance and service life.

That is, while permitting support and the normal range of movement of cutterbar45about axis56between lowered position180and raised position178, the positions corresponding to appropriate positions for cutting different types of crops, the load limiting apparatus prevents further rotational movement of elastic or resilient material68relative to housing60(FIG. 6), thereby limiting the extent of torsional flexure of elastic or resilient member68. This limitation of rotational movement provides several benefits including, substantially preventing damage to elastic or resilient member68associated with such excessive rotational movement of the resilient member relative to its housing, as well as substantially preventing premature loss of structural performance of elastic or resilient member68, sometimes referred to as “spring characteristics”. In addition, the load limiting device may provide structural support of the cutterbar components in some instances or positions, including a reduction or removal of torsional loads normally applied to the resilient material. By reducing or removing torsional loads applied to the resilient material when possible by virtue of the load limiting apparatus, service life, sometimes referred to as fatigue life of the resilient material, as well as the time duration at which high levels of structural performance can be maintained, may be significantly improved.

As shown collectively inFIGS. 13-14, an exemplary embodiment of torsion device390includes a load limiting apparatus394contained inside or substantially inside of torsion device390. Torsion device390includes a housing360having an inside surface366that is configured to rotatably receive an inner hub350having an outside surface348. A clearance342is provided between inside surface366and outside surface348to permit inner hub350to rotate about an axis56relative to housing360. Inner hub350and housing360have respective abutting features346,344to limit rotation relative to one another in at least one rotational direction about axis56. As further shown inFIG. 14, abutting feature346,344defines a tooth in each of respective inner hub350and housing360. As shownFIG. 14, a rotational movement range338is provided between corresponding abutting features346,344, which is sized to permit an amount of relative rotational movement of respective inner hub350relative to housing360prior to achieving abutting contact between the corresponding abutting features346,344. As shown inFIG. 14, sufficient rotational movement in a clockwise rotational direction, such as by rod58(not shown) which is configured to be received by inside surface336of inner hub350, achieves abutting contact between abutting features346,344. Upon achieving abutting contact between abutting features346,344, additional rotational movement in a clockwise rotational direction such as by rod58results in inner hub350and housing360rotating in unison, acting as a single mechanical assembly.

That is, as shown collectively inFIGS. 13-14, rotational movement range338provided between corresponding abutting features346,344permits relative rotational movement of respective inner hub350in a clockwise direction relative to housing360, and therefore results in an amount of torsional flexure of elastic or resilient member68prior to achieving abutting contact between the corresponding abutting features346,344. However, once abutting contact between corresponding abutting features346,344is achieved, further rotation of inner hub350in a clockwise direction relative to housing360results in inner hub350and housing360rotating in unison. Prevention of further relative rotation of inner hub350in the clockwise direction relative to housing360likewise prevents further torsional loading of resilient or elastic member68. The amount of rotational movement range338provided between corresponding abutting features346,344can be sized such that the amount of torsional flexure of elastic or resilient member68achieved can range anywhere between zero and an amount sufficient to raise the cutterbar. In other words, one having ordinary skill in the art appreciates that in the arrangement described, torsional flexure of elastic or resilient member68has the effect of reducing the amount of force associated with raising first portion46, and therefore, the cutterbar (FIG. 3). In one embodiment, the amount of torsional flexure of elastic or resilient member68(associated with an amount of rotational movement range338) can equal the force associated with raising first portion46. In yet another embodiment, the amount of torsional flexure of elastic or resilient member68(associated with an amount of rotational movement range338) can exceed the force associated with raising first portion46, although this construction would tend to reduce the beneficial effects the load limiting apparatus.

As further shown inFIG. 13, inner hub350and a sleeve376extend along axis56of torsion device390. In one embodiment, sleeve376and inner hub350are of unitary or one-piece construction. An elastic or resilient member330is either inserted or formed between a portion332of inside surface366of housing360and outside surface334of sleeve376, in which elastic or resilient member330(partially shown inFIG. 13) forms a non-rotational contact between surfaces366,334in a similar manner as previously discussed. In one embodiment, inner hub350may be safely positioned at one end of torsion device390along axis56. In another embodiment, inner hub350may be located at any position within or substantially within torsion device390. In yet another embodiment, multiple inner hubs350may be located at any position within or substantially within torsion device390.

In an alternate embodiment as shown inFIG. 13, torsion device390optionally includes a housing portion340that can be aligned and positioned relative to housing360as shown. One having ordinary skill in the art can appreciate that a second inner hub (not shown) can be configured with abutting features similar as shown inFIG. 14, with the exception that the relative rotational movement between the inner hub and the housing portion340would be opposite to that shown inFIG. 14. That is, in such a construction, abutting features between corresponding inner hubs and the inside surfaces of corresponding housing portions define a movement limiting apparatus in each opposed rotational direction of the inner hubs relative to the corresponding housing portions.