Abstract:
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. A residue managing unit in front of the coulters has individual floating residue wheels that reorient lengthwise stalks into transverse positions for severance by the coulters.

Description:
RELATED APPLICATION  
       [0001]     The present application is related to contemporaneously filed application Ser. No. ______ titled “One-Pass Primary Tillage Machine.” 
     
    
     TECHNICAL FIELD  
       [0002]     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  
       [0003]     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&#39;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.  
         [0004]     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.  
         [0005]     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.  
         [0006]     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. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a top plan view of a tillage machine constructed in accordance with the principles of the present invention;  
         [0008]      FIG. 2  is a side elevational view of such machine shown in its lowered, working position;  
         [0009]      FIG. 3  is a side elevational view of the machine similar to  FIG. 2  but illustrating the machine in its raised, transport position;  
         [0010]      FIG. 4  is an enlarged, top plan view of a bank of residue wheels that may be attached ahead of the residue cutting coulters of the machine to orient residue for most effective severance by the coulters;  
         [0011]      FIG. 5  is an enlarged cross-sectional view of one of the residue wheel assemblies taken substantially along line  5 - 5  of  FIG. 4 ;  
         [0012]      FIG. 6  is a view of a residue wheel assembly similar to  FIG. 5  and illustrating upper and lower limits of floating travel of the residue wheel;  
         [0013]      FIG. 7  is an exploded view of a portion of the gang of residue wheels illustrating details of construction;  
         [0014]      FIG. 8  is a fragmentary isometric view of the subframe that supports the conditioning discs at the rear of the machine;  
         [0015]      FIG. 8   a  is a fragmentary isometric view of the disc conditioner subframe taken from a different angle than  FIG. 8 ;  
         [0016]      FIG. 9  is a fragmentary isometric view of the front of the machine illustrating the manner in which the tool bar for the cutting coulters is mounted to the main frame and coupled with the hydraulic hold-down circuit;  
         [0017]      FIG. 10  is a schematic, top plan view of the various tools of the machine illustrating the manner in which they work the residue and soil to produce the desired field finish;  
         [0018]      FIG. 11  is a fragmentary cross-sectional view taken substantially along line  11 - 11  of  FIG. 10  and illustrating the condition of the field immediately behind the tillage shanks;  
         [0019]      FIG. 12  is a fragmentary cross-sectional view taken substantially along line  12 - 12  of  FIG. 10  and illustrating the condition of the soil immediately behind the first row of rear conditioning discs;  
         [0020]      FIG. 13  is a cross-sectional view taken substantially along line  13 - 13  of  FIG. 10  and illustrating the condition of the soil immediately behind the trailing row of soil conditioning discs; and  
         [0021]      FIG. 14  is a schematic diagram of the hydraulic hold-down circuit associate with the residue-cutting coulters of the machine. 
     
    
     DETAILED DESCRIPTION  
       [0022]     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.  
         [0023]     The tillage machine disclosed herein by way of example has a mobile main frame  10  that includes a pair of rearwardly diverging beams  12 ,  14  and a generally rectangular in plan box frame  16  rigidly affixed to beams  12 ,  14  beneath the same. Wheel assemblies  18  and  20  are secured to box frame  16  and support frame  10  for over-the-ground travel. Wheel assemblies  18  and  20  may be raised and lowered relative to frame  10  by hydraulic cylinders  22  and  24  for shifting the machine between a lowered, field working position as in  FIG. 2  and a raised transport position as in  FIG. 3 . Cylinders  22 ,  24  are connected at their upper ends to a pair of respective, somewhat upwardly arched, fixed structural members  26  and  28  and at their lower ends to the wheel assemblies  18 ,  20 .  
         [0024]     At the front end of frame  10  a generally triangular in plan hitch tongue  30  is pivotally connected to the beams  12  and  14  by horizontal pivots  32  to adapt hitch tongue  30  to swing upwardly and downwardly relative to main frame  10 . Hitch tongue  30  is provided with a clevis  34  or the like at its forwardmost end for coupling the machine to a towing tractor (not shown). A linkage  36  of known construction connects hitch tongue  30  with wheel assemblies  18 ,  20  to maintain main frame  10  level during raising and lowering thereof, while hitch tongue  30  pivots between level and inclined conditions as illustrated in  FIGS. 2 and 3 .  
         [0025]     The main frame  10  is provided with a group or squadron of deep tillage shanks  38  that are disposed at spaced locations across the machine. Shanks  38 , 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, shanks  38  are arranged in two primary ranks, namely a front rank of five shanks across box frame  16  generally ahead of wheel assemblies  18 ,  20  and a rear rank of four shanks across the rear of box frame  16  in alignment with the four ground wheels associated with wheel assemblies  18  and  20 . 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.  
         [0026]     Mounted on main frame  10  forwardly of shanks  38  is a gang of flat residue-cutting coulters  40 . In a preferred embodiment, each coulter  42  of the gang  40  has a diameter of 25 inches, and coulters  42  are arranged on 9 inch spacing with every other coulter  42  in line with one of the shanks  38 . Coulters  42  cut through residue and penetrate hard soils ahead of shanks  38  so as to properly size the residue, reduce its tendency to collect and build up on shanks  38 , and prepare a slit for the upper portions of shanks  38 . Coulters  42  are freely rotatable about a common transverse axis  44  and are preferably provided with double beveled peripheral edges that provide a relatively sharp periphery for slicing through the residue.  
         [0027]     Coulters  48 , as is well understood by those skilled in the art, are supported by a number of generally C-shaped mounts  46  secured to a common, transversely extending, tubular beam  48 . Beam  48 , in turn, is swingably secured to the front end of main frame  10  by a pair of lugs  50  and  52  as shown particularly in  FIG. 9 . Lugs  50 ,  52  are connected at their front ends to beams  12 ,  14  of main frame  10  by horizontal pivots  54  and  56  also shown in  FIG. 9 . To control up and down swinging movement of gang  40 , cross beam  48  is provided at its center with an upwardly projecting crank  58  operably coupled at its upper end with a down pressure hydraulic cylinder  60 . Hold-down cylinder  60  is connected at its rear end to box frame  16  and is operable not only to raise and lower gang  40  but to also maintain a constant live down pressure pushing gang  40  into the ground when the machine is in its working position of  FIG. 2 . Hold-down cylinder  60  is thus operable to maintain coulters  42  down in the soil to a depth of penetration determined by the hardness of the soil itself, regardless of the particular depth at which the shanks  38  are running. In other words, during field operations, the depth of coulters  42  is independent of shanks  38  in that shanks  38  are fixed to frame  10  and are depth-controlled by wheels  18 ,  20 , while coulter gang  40  is depth controlled by hold-down cylinder  60  that is operable to move gang  40  up and down relative to frame  10  and shanks  38 . A control circuit of which cylinder  60  is a part is illustrated in  FIG. 14  and will hereinafter be described in more detail.  
         [0028]     In a preferred embodiment of the invention, a residue managing attachment  62  is mounted on main frame  10  forwardly of coulter gang  40 . The primary function of attachment  62  is to engage and reorient residue if necessary so that stalks and other elongated items which might initially extend lengthwise of coulters  42  are turned sideways to facilitate severance by coulters  42 . Attachment  62  includes as its primary components a series of residue wheels  64 , one for each coulter  42 , which are arranged at an oblique angle relative to the path of travel of the machine and coulters  42 . Moreover, each residue wheel  64  is laterally offset with respect to the coulter for which it orients residue as shown in  FIG. 1 . It will be noted in that figure that while each residue wheel  64  is aligned fore-and-aft with one particular coulter  42 , it diverts residue to the next left adjacent coulter for severance.  
         [0029]     Details of construction of attachment  62  and residue wheels  64  are illustrated in  FIGS. 4-7 . As illustrated in those figures in particular, each residue wheel  64  is of generally flat, plate-like construction with a plurality of generally radially outwardly projecting fingers  66 . Each finger  66  tapers outwardly to a pointed tip  68  and is curved slightly rearwardly with respect to the normal direction of rotation of wheel  64  during ground engagement and forward motion of the machine. Wheels  64  rotate in a counterclockwise direction viewing  FIGS. 5 and 6 . It will be appreciated that wheels  64  may 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.  
         [0030]     The residue wheels  64  are all mounted for independent up and down swinging motion relative to one another but are carried by a common cross beam  70  that is suspended beneath the hitch tongue  30 . As illustrated particularly in  FIGS. 1 and 9 , cross beam  70  is immovably affixed to main frame  10  by a pair of fore-and-aft arms  72  and  74  (arm  74  only being visible in  FIG. 1 ), the rear ends of which are mounted on the pivots  32 . Each arm  72  has an upwardly and rearwardly projecting stabilizing ear  76  rigidly affixed thereto that is attached to mainframe  10  at pivot  54  so as to keep arms  72  from swinging up and down about pivots  32 .  
         [0031]     Each residue wheel  64  is rotatably mounted to the outer end of a support arm  78  which is, in turn, swingably mounted at its inner end to the cross beam  70 . Pivotal mounting of each arm  78  to cross beam  70  is accomplished through a cooperating pair of generally triangular in plan brackets  80  that are spaced apart along cross beam  70  and project rearwardly therefrom. Each bracket  80  includes a triangular top wall  82  and a rectangular downturned sidewall  84  that lies in a plane disposed at an approximately 45° angle to the path of travel of the machine. Adjacent its inner end, each support arm  78  is provided with a generally S-shaped arm  86  that cooperates with the inner end of arm  78  to present a mounting yoke that receives a transverse pivot bolt  88  and a sleeve  90  encircling bolt  88 . Bolt  88  extends between the two sidewalls  84  of a pair of adjacent brackets  80  so as to swingably attach support arm  78  to cross beam  70 .  
         [0032]     Residue wheels  64  are gravity-biased downwardly by their own weight. To prevent excessive downward movement, each arm  78  is provided with a forwardly projecting extension  92  that is disposed to abut the underside of overhead top wall  82  after a predetermined amount of downward movement of the outer end of arm  78  such that top wall  82  serves as a limit stop for downward movement of wheel  64 . At least several of the residue wheels  64  along beam  70 , i.e., those directly under hitch tongue  30 , are provided with stops to limit upward travel of those wheels. In this respect as illustrated in  FIGS. 5, 6  and  7 , those particular brackets  80  may be provided with a generally L-shaped stop weldment  94  comprising a vertical plate  96  and a horizontal plate  98 . Vertical plate  96  has a hole  100  ( FIG. 7 ) adjacent its front end through which the bolt  88  passes, while horizontal plate  98  has a hole  102  adjacent its forward end through which a vertical bolt  104  passes. Pivot bolt  88  and vertical bolt  104  thus attach stop weldment  94  to bracket  80 , positioning horizontal plate  98  under extension  92  of arm  78  for engagement thereby at the end of the upward path of travel of wheel  64  as illustrated in  FIG. 6 .  
         [0033]     Each residue wheel  64  has a generally horizontally L-shaped shield  106  associated therewith that is adjustably secured to the rearmost end of the corresponding support arm  78 . Each shield  106  is formed from flat sheet material and has a forward leg  108  located between the wheel  64  and corresponding arm  78 . A hole  110  ( FIG. 7 ) in forward leg  108  receives the spindle  112  of the corresponding residue wheel  64  so that shield  106  can be pivoted upwardly and downwardly between adjusted positions. Retention in a selected position of adjustment is provided by a bolt  114  ( FIG. 7 ) at the forwardmost end of leg  108  that passes though an arcuate slot  116  in forward leg  108 . Manifestly, loosening of bolt  114  permits rocking adjustment of shield  106  about spindle  112  to the extent permitted by slot  116 , while tightening of bolt  114  effectively retains shield  106  in a selected position of adjustment. Each shield  106  further includes a rear leg  118  projecting rearwardly from the rearmost extremity of forward leg  108  parallel with the path of travel of the machine.  
         [0034]     As illustrated in  FIG. 1 , each shield  106  is generally aligned fore-and-aft with a corresponding one of the trailing coulters  42 . Thus, the shield is in position to receive residue from the next residue wheel to the right as viewed in  FIG. 1  and to prevent such residue from moving leftwardly past shield  106  to the next left adjacent coulter  42 . 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 wheel  64  directly in front of its coulter for effective severance. Further, each shield  106  tends to lie on top of and pinch down the residue to prepare it for severance by the coulter and to cooperate in such severance.  
         [0035]     Supported at the rear of the machine is a group  120  of concavo-convex conditioning discs that mix residue into the soil behind shanks  38 , reduce clod size, and level the field. The discs of the group are arranged in at least two transverse rows, namely a front row  122  and a trailing row  124 . In one preferred embodiment, the discs of front row  122  are 24-inch smooth discs on 18-inch spacing with the discs indexed with respect to shanks  38 . That is to say, as illustrated in  FIGS. 1 and 10 , each front disc  126  is disposed somewhat laterally offset from a corresponding, forwardly disposed shank  38  so 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 discs  126  of front row  122  are 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 discs  126  have been oriented to throw the soil toward the right as the machine is viewed in plan in  FIG. 1 , discs  126  could alternatively be angled in the opposite direction to throw the soil leftwardly, in which event the row  122  of discs would be displaced somewhat to the right of the position illustrated in  FIG. 1  so that the rightmost disc would be outboard of the rightmost shank  38 .  
         [0036]     On the other hand, the discs  128  of trailing row  124  are preferably 24-inch fluted discs on 10-inch or 12-inch spacing and are angled oppositely to the front discs  126 . Discs  128  of trailing row  124  are thus more closely spaced than shanks  38  and front discs  126 , and there are more of the trailing discs  128  than the front discs  126 . While front discs  126  cut 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 discs  128  function to reduce clod size still further and to leave a level field finish. Both front and trailing rows of discs  122  and  124  mix and partially bury residue into the soil. In the illustrated embodiment, the group  120  of conditioning discs is also provided with a set of rear, transversely extending reels  130  that further level and smooth the field, although such reels  130  are purely optional.  
         [0037]     The discs  126  of front row  122  are 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 disc  126  has a generally C-shaped mount  132  that attaches the same to an overhead, tubular beam  134  extending perpendicular to the path of travel of the machine. Mounts  132  have open ends that face rearwardly with respect to the direction of travel of the machine.  
         [0038]     Similarly, the discs  128  of trailing row  124  are mounted for rotating movement about individual transversely oblique axes rather than being mounted on an obliquely disposed common spindle or shaft. Each disc  128  is rotatably supported by a generally reversely C-shaped mount  136  that is attached at its upper end to a tubular beam  138  common to all of the discs  128  and extending in perpendicular relationship to the path of travel of the machine. It is to be noted that in contrast to front mounts  132 , rear mounts  136  have their open ends facing forwardly while their closed ends face rearwardly. This unorthodox orientation of rear mounts  136  has been found to be especially beneficial in keeping the trailing row of discs  124  from plugging in spite of the narrow spacing thereof compared to front discs  126 . While the flutes of trailing discs  128  sometimes tend to carry soil upwardly and rearwardly as the discs rotate counterclockwise viewing  FIGS. 2 and 3 , the rearwardly disposed bodies of mounts  136  tend to block and deter further upward travel of soil and direct it back down to the ground. If the open ends of mounts  136  faced rearwardly as with the front row of discs  122 , there would be a greater tendency for uplifted soil from the closely spaced trailing discs  128  to be captured within the open areas defined by the C-shaped mounts  136 , contributing to plugging.  
         [0039]     The disc beams  134  and  138  are both part of a subframe denoted broadly by the numeral  140  that is swingably attached to the rear end of main frame  10  for up and down swinging movement. Detailed views of subframe  140  are shown in  FIGS. 8 and 8   a.  As illustrated therein, subframe  140  is generally rectangular in plan and has a pair of upstanding generally triangular mounting plates  142  and  144  rigidly affixed thereto adjacent its front end at widely spaced locations thereon. Mounting plates  142 ,  144  are provided with upper and lower corners  146  and  148  respectively which, in turn, are pivotally connected to upper and lower links  150  and  152  of respective four-bar linkages  154  and  156 . Each four-bar linkage  154 ,  156  has an upper rear pivot connection  158  with plate corner  146  and a lower rear pivot connection  160  with lower plate corner  148 . At its forward end, each linkage  154 ,  156  has an upper front pivot connection  162  with beam member  12  or  14  and a lower front pivot connection  164  with the same beam. Top links  150  are substantially the same length as lower links  152  such that as subframe  140  swings upwardly and downwardly, it remains generally level. Preferably, upper links  150  are in the nature of adjustable turnbuckles for selectively adjusting the length thereof.  
         [0040]     The four-bar linkages  154  and  156  are rigidly interconnected by a torque tube  166  that spans the lower links  152  adjacent their rear ends. Two pairs of upstanding plates  168  and  170  are rigidly affixed to torque tube  166  adjacent opposite ends thereof. Each pair of plates  168 ,  170  pivotally supports an inverted, generally L-shaped member  172  having a pivotal connection  174  with plates  168 ,  170  adjacent its lower end. A stop  176  spans each pair of plates  168 ,  170  adjacent their upper ends to limit forward swinging of L-member  172 . At its upper rear end, each L-member  172  is pivotally connected to the rod end of a hydraulic cylinder  178  that is pivotally connected at its anchor end to the subframe  140 .  
         [0041]     As a result of this arrangement, when cylinders  178  are in a retracted condition with L-members  172  away from stops  176 , subframe  140 , and thus the group of finishing discs  120 , is free to float up and down to a limited extent as front and trailing discs  126  and  128  engage the ground during forward movement of the machine. Front and trailing discs  122  and  124  thus are gravitationally biased into the ground at this time. If it is desired to raise subframe  140 , cylinders  178  are utilized for this purpose. However, initially, there is a certain amount of lost motion involved as the L-members  172  are swung forwardly until reaching the stops  176 . Thereafter, further extension of cylinders  178  results in the entire subframe  140  and four-bar linkages  154 ,  156  being raised upwardly relative to main frame  10 .  
         [0042]      FIG. 14  illustrates a hydraulic hold-down circuit broadly denoted by the numeral  180  that includes the hold-down cylinder  60  for maintaining constant down pressure against the coulter gang  40 . The rod end  182  of cylinder  60  is connected to coulter gang  40  via crank  58 , while the anchor end  184  of cylinder  160  is connected to main frame  10 . The geometry is such that fluid pressure attempting to contract cylinder  60  causes down pressure to be applied against coulter gang  40 . If coulter gang  40  is out of the ground as illustrated in  FIG. 3  when the machine is in its raised transport position, there is no resistance to downward swinging of coulter gang  40 , and cylinder  60  fully retracts to lower gang  40  to its fullest extent.  
         [0043]     As illustrated in  FIG. 14 , hold-down circuit  180  includes a pressure line  186  leading to the anchor end of cylinder  60  from a quick coupler  188  with the tractor hydraulic system (not shown). A return line  190  leads from the anchor end of cylinder  60  to another quick coupler  192  with the tractor hydraulic system. A control valve broadly denoted by the numeral  194  is interposed within supply line  186  between couplers  188  and cylinder  160  and is adapted to reduce the pressure of a constant supply of oil from the tractor. Valve  194  has an adjustable pressure reducing port  196  and internal valving that enables a portion of the flow that would otherwise pass through pressuring reducing port  196  to by-pass such port and exit valve  194  through by-pass line  198  that connects to return line  190  leading to tractor coupler  192 . Valve  194  also includes an internal relief valve and is fluidically connected to a gauge  200  for displaying the pressure of the fluid supplied to the rod end of cylinder  60 . One suitable valve for performing the desired pressure-reducing, by-pass, check and relief functions of valve  194  is available from Shoemaker Incorporated of Fort Wayne, Ind. as part no. 8136.  
         [0000]     Operation  
         [0044]     During field operations the machine is in the lowered operating position of  FIG. 2 . As the machine is drawn forwardly, the cross beam  70  associated with the residue managing unit  62  knocks down standing residue, and residue wheels  64  engage and orient stalks transverse to the trailing coulters  42 . Coulters  42 , under the influence of cylinder  60 , 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 coulters  42 . Shanks  38  enter the slits prepared by coulters  42  and deeply till and fracture the soil creating, as illustrated in  FIG. 11 , a series of furrows  202  bounded on opposite sides by ridges  204  of chunky soil and residue left by the wake of each shank  38 . This action is also illustrated in  FIG. 10 . At this stage, relatively large chunks or clods  206  exist in the ridges  204 .  
         [0045]     When the ridges  204  are engaged by the front row of conditioning discs  122 , the discs  126  thereof cut the clods  206  into smaller sizes to produce smaller clods  208  as illustrated in  FIG. 12 . Furthermore, the discs  126  throw the soil and residue from ridges  204  rightwardly into furrows  202  so as to produce a relatively level condition as illustrated in  FIG. 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 discs  128  as illustrated in  FIGS. 10 and 13 , the relatively closely spaced trailing discs  128  have the effect of further cutting the clods to produce yet smaller clods  210 , 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.  
         [0046]     It will be noted as illustrated particularly in  FIG. 13 , and as also seen in  FIG. 1 , that the discs  128  of trailing row  124  progressively taper toward smaller diameters as the right end of the row is approached. In the illustrated embodiment, the next-to-last disc  128  on the right is smaller than the other discs to the left, while the rightmost disc at the end of the row  124  is 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 discs  124 . It will be further appreciated that the addition of reels such as the reels  130  to the conditioning discs  120  aids in further reducing clod size and leveling the field.  
         [0047]     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.