One-pass primary tillage machine

A one-pass primary tillage machine provides a combination of shallow and deep tillage, residue cutting and mixing, and clod size reduction and leveling of the field to prepare the field for the next planting season. A front group of flat coulters slice through the residue to reduce its size, followed by deep shanks that improve the tilth of the soil to a point below the intended planting depth. Following the shanks, a group of concavo-convex conditioning discs mix the residue with the soil, reduce clod size, and level the field.

RELATED APPLICATION

The present application is related to contemporaneously filed application Ser. No. 10/901,776 titled “Residue Managing Attachment for Primary Tillage Machine.”

TECHNICAL FIELD

The present invention relates to the field of agricultural tillage equipment and, more particularly, to a machine having particular utility as a primary fall tillage tool with the ability to leave the field suitably finished with minimal requirements for additional tillage prior to spring planting.

BACKGROUND AND SUMMARY

It is known in the art to provide single-pass tillage implements which perform both shallow and deeper, primary tillage in a single pass. Typically, gangs of concavo-convex discs are utilized to perform the shallow tillage, while behind the discs sturdy shanks with various types of points are utilized to perform the deeper tillage. The discs are also typically used to cut and bury residue, to varying degrees. Several conventional machines, in an effort to have the soil in a fairly level condition by the time of the next planting season, use cooperating pairs of discs behind the tillage shanks to fill in furrows left by the shanks. Such discs typically are positioned to engage the two ridges produced by each advancing shank and to converge the ridges back into the shank's furrow whereby to create a raised berm that will settle down to a more level condition over the winter months before the next spring planting season. Some conventional machines also provide coulters at the front of the machine for residue-cutting purposes.

In one aspect the present invention is intended to provide an improved single-pass primary fall tillage machine which leaves the field in better condition for spring planting operations than has heretofore been possible. The machine not only cuts and partially buries residue left from harvesting operations, but also provides both deep and shallow tillage while leaving a smoother, more level field with smaller clod size.

The present invention provides a number of novel features, both individually and in combination. In one preferred embodiment, the machine has a group of laterally spaced, deep tillage shanks that are preceded by a transversely extending group of flat, residue-cutting coulters. Following the shanks is a group of soil-conditioning, concavo-convex discs that pulverize, level, and smooth the soil. Preferably, although not necessarily, the coulters are preceded by a gang of freely rotating residue wheels that engage and orient residue transversely for better severance by the coulters. Preferably, the residue wheels are each independently mounted, free-floating, and gravity-biased downwardly. The coulters are pressed downwardly as a group by a hydraulic hold-down circuit that allows the coulters to penetrate the soil to the extent necessary to achieve a firm backstop against which the coulters may cut the residue. The depth of penetration of the coulters is thus made independent of the depth of the tillage shanks, which are controlled by transport wheels on the main frame of the machine.

The conditioning discs at the rear of the machine are preferably arranged in at least two transversely extending, parallel rows with the discs of a trailing row being more closely spaced and greater in number than those of the front row. Preferably, the spacing of the discs in the trailing row is less than the spacing between the shanks, while the spacing of the discs in the front row is the same as the spacing between the shanks. While the discs in the front row are indexed with the shanks and are located to move soil from the shank ridge laterally back into the furrow behind the shank, the discs in the trailing row, being more closely spaced and angled in the opposite direction, serve the function of reducing clod size, mixing, and leveling the soil to provide a finish suitable for spring planting. Preferably, the discs of the conditioner are all individually mounted on transverse beams by generally C-shaped mounts, with at least the mounts of the discs in the trailing row having their open ends facing forwardly to minimize plugging. Best results are obtained when the discs of the trailing row are fluted.

DETAILED DESCRIPTION

The present invention is susceptible of embodiment in many different forms. While the drawings illustrate and the specification describes certain preferred embodiments of the invention, it is to be understood that such disclosure is by way of example only. There is no intent to limit the principles of the present invention to the particular disclosed embodiments.

The tillage machine disclosed herein by way of example has a mobile main frame10that includes a pair of rearwardly diverging beams12,14and a generally rectangular in plan box frame16rigidly affixed to beams12,14beneath the same. Wheel assemblies18and20are secured to box frame16and support frame10for over-the-ground travel. Wheel assemblies18and20may be raised and lowered relative to frame10by hydraulic cylinders22and24for shifting the machine between a lowered, field working position as inFIG. 2and a raised transport position as inFIG. 3. Cylinders22,24are connected at their upper ends to a pair of respective, somewhat upwardly arched, fixed structural members26and28and at their lower ends to the wheel assemblies18,20.

At the front end of frame10a generally triangular in plan hitch tongue30is pivotally connected to the beams12and14by horizontal pivots32to adapt hitch tongue30to swing upwardly and downwardly relative to main frame10. Hitch tongue30is provided with a clevis34or the like at its forwardmost end for coupling the machine to a towing tractor (not shown). A linkage36of known construction connects hitch tongue30with wheel assemblies18,20to maintain main frame10level during raising and lowering thereof, while hitch tongue30pivots between level and inclined conditions as illustrated inFIGS. 2 and 3.

The main frame10is provided with a group or squadron of deep tillage shanks38that are disposed at spaced locations across the machine. Shanks38, including their lowermost points, may take a variety of different forms as well understood by those skilled in the art including, for example, parabolic deep till shanks, a combination of deep till and heavy-duty chisel shanks, or all chisel shanks. In a preferred embodiment, shanks38are arranged in two primary ranks, namely a front rank of five shanks across box frame16generally ahead of wheel assemblies18,20and a rear rank of four shanks across the rear of box frame16in alignment with the four ground wheels associated with wheel assemblies18and20. The shank pattern is such that the shanks of the rear rank are interposed between the shanks of the front rank on 18 inch spacing. No shank is closer than 36 inches on the same beam.

Mounted on main frame10forwardly of shanks38is a gang of flat residue-cutting coulters40. In a preferred embodiment, each coulter42of the gang40has a diameter of 25 inches, and coulters42are arranged on 9 inch spacing with every other coulter42in line with one of the shanks38. Coulters42cut through residue and penetrate hard soils ahead of shanks38so as to properly size the residue, reduce its tendency to collect and build up on shanks38, and prepare a slit for the upper portions of shanks38. Coulters42are freely rotatable about a common transverse axis44and are preferably provided with double beveled peripheral edges that provide a relatively sharp periphery for slicing through the residue.

Coulters48, as is well understood by those skilled in the art, are supported by a number of generally C-shaped mounts46secured to a common, transversely extending, tubular beam48. Beam48, in turn, is swingably secured to the front end of main frame10by a pair of lugs50and52as shown particularly inFIG. 9. Lugs50,52are connected at their front ends to beams12,14of main frame10by horizontal pivots54and56also shown inFIG. 9. To control up and down swinging movement of gang40, cross beam48is provided at its center with an upwardly projecting crank58operably coupled at its upper end with a down pressure hydraulic cylinder60. Hold-down cylinder60is connected at its rear end to box frame16and is operable not only to raise and lower gang40but to also maintain a constant live down pressure pushing gang40into the ground when the machine is in its working position ofFIG. 2. Hold-down cylinder60is thus operable to maintain coulters42down in the soil to a depth of penetration determined by the hardness of the soil itself, regardless of the particular depth at which the shanks38are running. In other words, during field operations, the depth of coulters42is independent of shanks38in that shanks38are fixed to frame10and are depth-controlled by wheels18,20, while coulter gang40is depth controlled by hold-down cylinder60that is operable to move gang40up and down relative to frame10and shanks38. A control circuit of which cylinder60is a part is illustrated inFIG. 14and will hereinafter be described in more detail.

In a preferred embodiment of the invention, a residue managing attachment62is mounted on main frame10forwardly of coulter gang40. The primary function of attachment62is to engage and reorient residue if necessary so that stalks and other elongated items which might initially extend lengthwise of coulters42are turned sideways to facilitate severance by coulters42. Attachment62includes as its primary components a series of residue wheels64, one for each coulter42, which are arranged at an oblique angle relative to the path of travel of the machine and coulters42. Moreover, each residue wheel64is laterally offset with respect to the coulter for which it orients residue as shown inFIG. 1. It will be noted in that figure that while each residue wheel64is aligned fore-and-aft with one particular coulter42, it diverts residue to the next left adjacent coulter for severance.

Details of construction of attachment62and residue wheels64are illustrated inFIGS. 4–7. As illustrated in those figures in particular, each residue wheel64is of generally flat, plate-like construction with a plurality of generally radially outwardly projecting fingers66. Each finger66tapers outwardly to a pointed tip68and is curved slightly rearwardly with respect to the normal direction of rotation of wheel64during ground engagement and forward motion of the machine. Wheels64rotate in a counterclockwise direction viewingFIGS. 5 and 6. It will be appreciated that wheels64may take other forms within the scope of the present invention, such as being of solid construction, but it has been found that spaced, rearwardly curved, pointed fingers work best.

The residue wheels64are all mounted for independent up and down swinging motion relative to one another but are carried by a common cross beam70that is suspended beneath the hitch tongue30. As illustrated particularly inFIGS. 1 and 9, cross beam70is immovably affixed to main frame10by a pair of fore-and-aft arms72and74(arm74only being visible inFIG. 1), the rear ends of which are mounted on the pivots32. Each arm72has an upwardly and rearwardly projecting stabilizing ear76rigidly affixed thereto that is attached to mainframe10at pivot54so as to keep arms72from swinging up and down about pivots32.

Each residue wheel64is rotatably mounted to the outer end of a support arm78which is, in turn, swingably mounted at its inner end to the cross beam70. Pivotal mounting of each arm78to cross beam70is accomplished through a cooperating pair of generally triangular in plan brackets80that are spaced apart along cross beam70and project rearwardly therefrom. Each bracket80includes a triangular top wall82and a rectangular downturned sidewall84that lies in a plane disposed at an approximately 45° angle to the path of travel of the machine. Adjacent its inner end, each support arm78is provided with a generally S-shaped arm86that cooperates with the inner end of arm78to present a mounting yoke that receives a transverse pivot bolt88and a sleeve90encircling bolt88. Bolt88extends between the two sidewalls84of a pair of adjacent brackets80so as to swingably attach support arm78to cross beam70.

Residue wheels64are gravity-biased downwardly by their own weight. To prevent excessive downward movement, each arm78is provided with a forwardly projecting extension92that is disposed to abut the underside of overhead top wall82after a predetermined amount of downward movement of the outer end of arm78such that top wall82serves as a limit stop for downward movement of wheel64. At least several of the residue wheels64along beam70, i.e., those directly under hitch tongue30, are provided with stops to limit upward travel of those wheels. In this respect as illustrated inFIGS. 5,6and7, those particular brackets80may be provided with a generally L-shaped stop weldment94comprising a vertical plate96and a horizontal plate98. Vertical plate96has a hole100(FIG. 7) adjacent its front end through which the bolt88passes, while horizontal plate98has a hole102adjacent its forward end through which a vertical bolt104passes. Pivot bolt88and vertical bolt104thus attach stop weldment94to bracket80, positioning horizontal plate98under extension92of arm78for engagement thereby at the end of the upward path of travel of wheel64as illustrated inFIG. 6.

Each residue wheel64has a generally horizontally L-shaped shield106associated therewith that is adjustably secured to the rearmost end of the corresponding support arm78. Each shield106is formed from flat sheet material and has a forward leg108located between the wheel64and corresponding arm78. A hole110(FIG. 7) in forward leg108receives the spindle112of the corresponding residue wheel64so that shield106can be pivoted upwardly and downwardly between adjusted positions. Retention in a selected position of adjustment is provided by a bolt114(FIG. 7) at the forwardmost end of leg108that passes though an arcuate slot116in forward leg108. Manifestly, loosening of bolt114permits rocking adjustment of shield106about spindle112to the extent permitted by slot116, while tightening of bolt114effectively retains shield106in a selected position of adjustment. Each shield106further includes a rear leg118projecting rearwardly from the rearmost extremity of forward leg108parallel with the path of travel of the machine.

As illustrated inFIG. 1, each shield106is generally aligned fore-and-aft with a corresponding one of the trailing coulters42. Thus, the shield is in position to receive residue from the next residue wheel to the right as viewed inFIG. 1and to prevent such residue from moving leftwardly past shield106to the next left adjacent coulter42. This prevents an excessive amount of residue from being collected in front of any one coulter, which would impede the slicing ability of the coulter. The shield also has the effect of positioning the residue from the corresponding wheel64directly in front of its coulter for effective severance. Further, each shield106tends to lie on top of and pinch down the residue to prepare it for severance by the coulter and to cooperate in such severance.

Supported at the rear of the machine is a group120of concavo-convex conditioning discs that mix residue into the soil behind shanks38, reduce clod size, and level the field. The discs of the group are arranged in at least two transverse rows, namely a front row122and a trailing row124. In one preferred embodiment, the discs of front row122are 24-inch smooth discs on 18-inch spacing with the discs indexed with respect to shanks38. That is to say, as illustrated inFIGS. 1 and 10, each front disc126is disposed somewhat laterally offset from a corresponding, forwardly disposed shank38so as to be in position to receive one of the ridges from such shank and displace it laterally back toward the furrow left by the shank. As illustrated, the discs126of front row122are all obliquely disposed with respect to the path of travel of the machine so as to effect such lateral soil displacement action. In this respect, although discs126have been oriented to throw the soil toward the right as the machine is viewed in plan inFIG. 1, discs126could alternatively be angled in the opposite direction to throw the soil leftwardly, in which event the row122of discs would be displaced somewhat to the right of the position illustrated inFIG. 1so that the rightmost disc would be outboard of the rightmost shank38.

On the other hand, the discs128of trailing row124are preferably 24-inch fluted discs on 10-inch or 12-inch spacing and are angled oppositely to the front discs126. Discs128of trailing row124are thus more closely spaced than shanks38and front discs126, and there are more of the trailing discs128than the front discs126. While front discs126cut clods and perform an initial leveling action by shifting some of the soil from a shank ridge into the furrow left by the shank, the trailing discs128function to reduce clod size still further and to leave a level field finish. Both front and trailing rows of discs122and124mix and partially bury residue into the soil. In the illustrated embodiment, the group120of conditioning discs is also provided with a set of rear, transversely extending reels130that further level and smooth the field, although such reels130are purely optional.

The discs126of front row122are all individually mounted for rotation about individual, transversely oblique axes rather than journalled on a common long shaft that is obliquely disposed. In this respect, each disc126has a generally C-shaped mount132that attaches the same to an overhead, tubular beam134extending perpendicular to the path of travel of the machine. Mounts132have open ends that face rearwardly with respect to the direction of travel of the machine.

Similarly, the discs128of trailing row124are mounted for rotating movement about individual transversely oblique axes rather than being mounted on an obliquely disposed common spindle or shaft. Each disc128is rotatably supported by a generally reversely C-shaped mount136that is attached at its upper end to a tubular beam138common to all of the discs128and extending in perpendicular relationship to the path of travel of the machine. It is to be noted that in contrast to front mounts132, rear mounts136have their open ends facing forwardly while their closed ends face rearwardly. This unorthodox orientation of rear mounts136has been found to be especially beneficial in keeping the trailing row of discs124from plugging in spite of the narrow spacing thereof compared to front discs126. While the flutes of trailing discs128sometimes tend to carry soil upwardly and rearwardly as the discs rotate counterclockwise viewingFIGS. 2 and 3, the rearwardly disposed bodies of mounts136tend to block and deter further upward travel of soil and direct it back down to the ground. If the open ends of mounts136faced rearwardly as with the front row of discs122, there would be a greater tendency for uplifted soil from the closely spaced trailing discs128to be captured within the open areas defined by the C-shaped mounts136, contributing to plugging.

The disc beams134and138are both part of a subframe denoted broadly by the numeral140that is swingably attached to the rear end of main frame10for up and down swinging movement. Detailed views of subframe140are shown inFIGS. 8 and 8a. As illustrated therein, subframe140is generally rectangular in plan and has a pair of upstanding generally triangular mounting plates142and144rigidly affixed thereto adjacent its front end at widely spaced locations thereon. Mounting plates142,144are provided with upper and lower corners146and148respectively which, in turn, are pivotally connected to upper and lower links150and152of respective four-bar linkages154and156. Each four-bar linkage154,156has an upper rear pivot connection158with plate corner146and a lower rear pivot connection160with lower plate corner148. At its forward end, each linkage154,156has an upper front pivot connection162with beam member12or14and a lower front pivot connection164with the same beam. Top links150are substantially the same length as lower links152such that as subframe140swings upwardly and downwardly, it remains generally level. Preferably, upper links150are in the nature of adjustable turnbuckles for selectively adjusting the length thereof.

The four-bar linkages154and156are rigidly interconnected by a torque tube166that spans the lower links152adjacent their rear ends. Two pairs of upstanding plates168and170are rigidly affixed to torque tube166adjacent opposite ends thereof. Each pair of plates168,170pivotally supports an inverted, generally L-shaped member172having a pivotal connection174with plates168,170adjacent its lower end. A stop176spans each pair of plates168,170adjacent their upper ends to limit forward swinging of L-member172. At its upper rear end, each L-member172is pivotally connected to the rod end of a hydraulic cylinder178that is pivotally connected at its anchor end to the subframe140.

As a result of this arrangement, when cylinders178are in a retracted condition with L-members172away from stops176, subframe140, and thus the group of finishing discs120, is free to float up and down to a limited extent as front and trailing discs126and128engage the ground during forward movement of the machine. Front and trailing discs122and124thus are gravitationally biased into the ground at this time. If it is desired to raise subframe140, cylinders178are utilized for this purpose. However, initially, there is a certain amount of lost motion involved as the L-members172are swung forwardly until reaching the stops176. Thereafter, further extension of cylinders178results in the entire subframe140and four-bar linkages154,156being raised upwardly relative to main frame10.

FIG. 14illustrates a hydraulic hold-down circuit broadly denoted by the numeral180that includes the hold-down cylinder60for maintaining constant down pressure against the coulter gang40. The rod end182of cylinder60is connected to coulter gang40via crank58, while the anchor end184of cylinder160is connected to main frame10. The geometry is such that fluid pressure attempting to contract cylinder60causes down pressure to be applied against coulter gang40. If coulter gang40is out of the ground as illustrated inFIG. 3when the machine is in its raised transport position, there is no resistance to downward swinging of coulter gang40, and cylinder60fully retracts to lower gang40to its fullest extent.

As illustrated inFIG. 14, hold-down circuit180includes a pressure line186leading to the anchor end of cylinder60from a quick coupler188with the tractor hydraulic system (not shown). A return line190leads from the anchor end of cylinder60to another quick coupler192with the tractor hydraulic system. A control valve broadly denoted by the numeral194is interposed within supply line186between couplers188and cylinder160and is adapted to reduce the pressure of a constant supply of oil from the tractor. Valve194has an adjustable pressure reducing port196and internal valving that enables a portion of the flow that would otherwise pass through pressuring reducing port196to by-pass such port and exit valve194through by-pass line198that connects to return line190leading to tractor coupler192. Valve194also includes an internal relief valve and is fluidically connected to a gauge200for displaying the pressure of the fluid supplied to the rod end of cylinder60. One suitable valve for performing the desired pressure-reducing, by-pass, check and relief functions of valve194is available from Shoemaker Incorporated of Fort Wayne, Ind. as part no. 8136.

Operation

During field operations the machine is in the lowered operating position ofFIG. 2. As the machine is drawn forwardly, the cross beam70associated with the residue managing unit62knocks down standing residue, and residue wheels64engage and orient stalks transverse to the trailing coulters42. Coulters42, under the influence of cylinder60, penetrate the residue and soil until encountering sufficient resistance to preclude further downward movement thereof, thus being provided with an anvil-like backstop against which the residue can be cleanly severed into shorter lengths by the coulters42. Shanks38enter the slits prepared by coulters42and deeply till and fracture the soil creating, as illustrated inFIG. 11, a series of furrows202bounded on opposite sides by ridges204of chunky soil and residue left by the wake of each shank38. This action is also illustrated inFIG. 10. At this stage, relatively large chunks or clods206exist in the ridges204.

When the ridges204are engaged by the front row of conditioning discs122, the discs126thereof cut the clods206into smaller sizes to produce smaller clods208as illustrated inFIG. 12. Furthermore, the discs126throw the soil and residue from ridges204rightwardly into furrows202so as to produce a relatively level condition as illustrated inFIG. 12, at the same time performing a degree of mixing of the residue into the soil. When the soil is then engaged by the trailing row of conditioning discs128as illustrated inFIGS. 10 and 13, the relatively closely spaced trailing discs128have the effect of further cutting the clods to produce yet smaller clods210, to further mix the residue and soil, and to significantly smooth and level the soil. Ideally, no ridges or berms are left when the machine of the present invention has completed its work within a field.

It will be noted as illustrated particularly inFIG. 13, and as also seen inFIG. 1, that the discs128of trailing row124progressively taper toward smaller diameters as the right end of the row is approached. In the illustrated embodiment, the next-to-last disc128on the right is smaller than the other discs to the left, while the rightmost disc at the end of the row124is even smaller than its next adjacent disc to the left. This helps prevent the formation of a berm at the right end of the trailing row of discs124. It will be further appreciated that the addition of reels such as the reels130to the conditioning discs120aids in further reducing clod size and leveling the field.

The inventor(s) hereby state(s) his/their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of his/their invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set out in the following claims.