Abstract:
A tillage apparatus including a frame having tillers, land wheels supporting the frame, and press wheels on the frame is disclosed. In one form, the frame has a forward section and a rearward section supporting the press wheels. The rearward section can pivot radially with respect to the direction of movement of the forward section. In another form, the frame includes a linkage assembly connected to the rearward section. An inner wheel support gang having press wheels is attached to a pivoting mounting bracket of the linkage assembly such that the inner wheel support gang can pivot vertically. In another form, the apparatus includes a weight transfer device including a linkage connecting a boom and the forward section. A biasing means pivotally connected to the forward section and to the linkage distributes weight from the boom to the forward section to the rearward section and to the press wheels.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
       [0001]     Not Applicable.  
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH  
       [0002]     Not Applicable.  
       BACKGROUND OF THE INVENTION  
       [0003]     1. Field of the Invention  
         [0004]     The present invention relates to an agricultural tillage apparatus including rear press wheels, and more particularly, the invention pertains to an agricultural tillage apparatus that provides improved frame flexibility such that the rear press wheels can more closely follow the contours of the ground, that provides improved weight distribution for the rear press wheels, and that provides adjustable weight transfer to the rear press wheels.  
         [0005]     2. Description of the Related Art  
         [0006]     Typical agricultural seeders are wheeled implements which are towed by agricultural work vehicles such as tractors. A seeder has a frame structure which has containers for seeds and a number of seed insertion devices such as shank type seed drills. The seed drills are arranged in horizontal rows to provide uniform application of the seeds in rows in the soil. The seeder frame structure is supported by a number of wheels. Typically the frame structure has a number of front land wheels and rear press wheels. The rear press wheels stabilize the seeder and compact the soil over the planted seeds. Compaction immediately after planting is very beneficial to crop yields. When soil is packed around the newly-planted seed, moisture is retained in the soil by expelling the air in the soil. As a result, the seed does not dry out and can draw water up for growth.  
         [0007]     Various seeding and/or compaction devices for packing the soil after tilling are known in the prior art. In these devices, separate land wheels are provided to support the implement (including the drills and rear press wheels) when raised for turning or transport to a different location. In operation, the drills and press wheels are lowered so that the rear press wheels track a path behind the drills to compact the soil.  
         [0008]     Some known seeding and/or compaction devices suffer from uneven weight distribution on the land wheels and rear press wheels. This can cause seed insertion which is uneven and/or deeper or shallower than desired, and uneven soil compaction in seeded areas. U.S. Pat. No. 6,125,778 has proposed one solution to this problem by providing a seeder with a weight distribution system such that weight on the front wheels is distributed to the work vehicle via the tow hitch and the rear wheels.  
         [0009]     Some known seeding and/or compaction devices are also disadvantageous in that the rear press wheels are unable to independently follow the contours of the ground. This can result in uneven compaction in tilled areas. U.S. Pat. No. 4,519,460 has proposed one solution to this problem by providing a tillage implement in which the rear press wheels are able to independently follow the contours of the ground.  
         [0010]     While solutions has been proposed to the problems associated with uneven seed insertion and uneven soil compaction, there still exists a need for an improved agricultural tillage apparatus that provides rear press wheels that can more closely follow the contours of the ground, that provides improved weight distribution for the rear press wheels, and that provides adjustable weight transfer to the rear press wheels.  
       SUMMARY OF THE INVENTION  
       [0011]     The foregoing needs are met by a tillage apparatus according to the invention. The tillage apparatus includes a flexible frame such that rear press wheels can more closely follow the contours of the ground thereby providing more even seed insertion and soil compaction. The tillage apparatus also provides improved weight distribution for the rear press wheels thereby providing more even seed insertion and soil compaction. In addition, the tillage apparatus provides adjustable weight transfer to the rear press wheels thereby providing more even seed insertion and soil compaction.  
         [0012]     In one aspect, the tillage apparatus includes a frame including a forward frame section having a plurality of tillers and a rearward frame section having a plurality of tillers, and at least two rotatable land wheels supporting the frame. At least one wheel support gang is attached to the rearward frame section, and a plurality of rotatable press wheels are suspended from each wheel support gang. The forward frame section has an axis in a direction of movement of the apparatus when tilling the field and the rearward frame section can pivot radially with respect to the axis of the forward frame section such that a pitch of the forward frame section follows a contour of the field encountered by the land wheels and a pitch of the rearward frame section follows a contour of the field encountered by the press wheels when the tilling the field. Thus, the pitch of the forward frame section is controlled by land wheels and the pitch of the rearward frame section is controlled by press wheels. The flexible frame is provided so that rear press wheels can more closely follow the contours of the ground thereby providing more even seed insertion and soil compaction.  
         [0013]     A crossbar may be attached to the rearward frame section. The crossbar has an axis in a direction of movement of the apparatus when tilling the field. Each wheel support gang may be pivotally attached to the crossbar such that each wheel support gang can pivot radially with respect to the axis of the crossbar. The apparatus may include two outermost wheel support gangs attached to the crossbar with each of the outermost wheel support gangs having a plurality of rotatable press wheels suspended therefrom. In this arrangement, the pitch of the rearward frame section follows a contour of the field encountered by the press wheels of the outermost wheel support gangs when tiling the field. The apparatus may further include at least one inner wheel support gang attached to the crossbar between the outermost support gangs with each inner wheel support gang having a plurality of rotatable press wheels suspended therefrom.  
         [0014]     The frame may include a boom. The forward frame section can be mounted to the boom and the land wheels can be mounted under the boom. A rockshaft may be pivotally mounted to the boom with the forward frame section being attached to the rockshaft. The forward frame section may be attached to the rearward frame section, and an actuator may be connected to the rockshaft and the forward frame section such that movement of the actuator rotates the rockshaft thereby causing a vertical elevation change in the forward frame section and the rearward frame section.  
         [0015]     The apparatus may include land wheels, a central portion, a left wing portion pivotally mounted on the central portion, and a right wing portion pivotally mounted on the central portion. Both the left wing portion and the right wing portion may include one or more forward frame sections having a plurality of tillers and one or more rearward frame sections having a plurality of tillers. One or more wheel support gangs is attached to each rearward frame section, and a plurality of rotatable press wheels are suspended from each wheel support gang. A pitch of each forward frame section follows a contour of the field encountered by the land wheels when the tilling the field, and a pitch of each rearward frame section follows a contour of the field encountered by the press wheels mounted on each wheel support gang attached to the rearward frame section when tilling the field.  
         [0016]     In another aspect, the tillage apparatus includes a frame including a rearward frame section having a plurality of tillers. A crossbar is attached to the rearward frame section, and the crossbar has an axis in a direction of movement of the apparatus when tilling the field. An outermost wheel support gang is attached to the crossbar such that the outermost wheel support gang can pivot radially with respect to the axis of the crossbar. Rotatable press wheels are suspended from the outermost wheel support gang. A linkage assembly is connected to the rearward frame section and to the crossbar inward from the outermost wheel support gang. An inner wheel support gang is attached to a pivoting mounting bracket of the linkage assembly such that the inner wheel support gang can pivot radially with respect to the axis of the crossbar and can pivot in the direction of the axis of the crossbar. A plurality of rotatable press wheels are suspended from the inner wheel support gang. When the apparatus is pulled across the field during tilling, the press wheels of the outermost wheel support gang follow a contour of the field and the inner wheel support gang pivots radially with respect to the axis of the crossbar and pivots away or toward the direction of the axis of the crossbar such that the press wheels of the inner wheel support gang follow a contour of the field. Thus, the tillage apparatus provides improved weight distribution for the rear press wheels thereby providing more even seed insertion and soil compaction.  
         [0017]     The linkage assembly may include a compression strut connected to the mounting bracket and the rearward frame section, and the linkage assembly may include a frame arm connected to the mounting bracket below the compression strut and connected to the rearward frame section. As a result, pivoting of the mounting bracket toward the direction of the axis of the crossbar vertically raises the inner wheel support gang and vertically lowers the outermost wheel support gang and pivoting of the mounting bracket away from the direction of the axis of the crossbar vertically lowers the inner wheel support gang and vertically raises the outermost wheel support gang.  
         [0018]     A second outermost wheel support gang may also be attached to the crossbar such that the second outermost wheel support gang can pivot radially with respect to the axis of the crossbar. The second outermost wheel support gang is positioned on the crossbar on a side of the inner wheel support gang opposite the outermost wheel support gang, and a plurality of rotatable press wheels are suspended from the second outermost wheel support gang. The press wheels of the second outermost wheel support gang follow a contour of the field when the apparatus is pulled across the field. A pitch of the rearward frame section can also follow the contour of the field encountered by the press wheels of the outermost wheel support gang and the press wheels of the second outermost wheel support gang when the apparatus is pulled across the field. Thus, a mechanism is provided whereby the weight of the frame and the tillers can be applied to three press wheel gangs in even and proportionate amounts while allowing the center inner press wheel gang to change elevation independent of the outermost gangs.  
         [0019]     Pivoting of the mounting bracket toward the direction of the axis of the crossbar vertically raises the inner wheel support gang and vertically lowers the outermost wheel support gang and the second outermost wheel support gang and pivoting of the mounting bracket away from the direction of the axis of the crossbar vertically lowers the inner wheel support gang and vertically raises the outermost wheel support gang and the second outermost wheel support gang.  
         [0020]     The mounting bracket may include means for adjusting the spacing between a junction of the compression strut and the mounting bracket and a junction of the frame arm and the mounting bracket thereby adjusting distribution of loads on the inner wheel support gang and the outermost wheel support gang and the second outermost wheel support gang when the apparatus is pulled across the field.  
         [0021]     In yet another aspect, the tillage apparatus includes a frame having a boom, a plurality of tillers, a forward frame section, and a rearward frame section connected to the forward frame section. At least one wheel support gang is attached to the rearward frame section, and rotatable press wheels are suspended from each wheel support gang. The apparatus includes a weight transfer device including a linkage connecting the boom and the forward frame section. The weight transfer device includes biasing means pivotally connected to the forward frame section and to the linkage. The biasing means distributes weight from the boom to the forward frame section to the rearward frame section and to the press wheels by applying a downward force on the linkage. The forward frame section can be moved from a raised position in which the biasing means does not apply a downward force on the linkage to a lower working position in which the biasing means applies a downward force on the linkage.  
         [0022]     In one form, the biasing means includes a pivoting bolt connected to the forward frame section and a spring positioned over the bolt between an upper end plate connected to the bolt and a pin attached to the linkage such that the spring applies the downward force on the linkage. The biasing means may further comprise means for adjusting a position of the upper end plate with respect to the pin attached to the linkage such that the downward force can be varied by varying a length of the spring.  
         [0023]     The linkage may include a first link pivotally connected to the boom and a second link pivotally connected to the first link and the forward frame section wherein the biasing means is pivotally connected to the second link. The linkage may further include means for adjusting the position of the second link with respect to the forward frame section such that the downward force can be varied.  
         [0024]     Thus, a mechanism is provided whereby the weight of the front boom can be adjustably transferred to rear press wheels by creating torsional force about their connecting pivot.  
         [0025]     These and other features, aspects, and advantages of the present invention will become better understood upon consideration of the following detailed description, drawings, and appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0026]      FIG. 1  is a top front perspective view of a tillage apparatus according to the invention with the right wing portion omitted.  
         [0027]      FIG. 2  is a top rear perspective view of one frame section of the tillage apparatus of  FIG. 1 .  
         [0028]      FIG. 3  is a top rear perspective view of the frame section of  FIG. 2  with the rearward frame section radially pivoted with respect to the forward frame section.  
         [0029]      FIG. 4  is partial perspective view of a linkage assembly for mounting the inner press wheel gang to the rearward frame section of the frame of  FIG. 2 .  
         [0030]      FIG. 5  is a partial top rear perspective view of the frame section of  FIG. 2  with the inner press wheels in their uppermost vertical position and the outer press wheels in their lowermost vertical position.  
         [0031]      FIG. 6  is a partial top rear perspective view of the frame section of  FIG. 2  with the inner press wheels in their lowermost vertical position and the outer press wheels in their uppermost vertical position.  
         [0032]      FIG. 7  is a view taken along lines  7 - 7  of  FIG. 2  showing an adjustable tillage apparatus weight transfer device according to the invention in an upward position.  
         [0033]      FIG. 8  is a view similar to  FIG. 7  showing the adjustable tillage apparatus weight transfer device according to the invention in an lowered position. 
     
    
       [0034]     Like reference numerals are used to depict like parts throughout the Figures.  
       DETAILED DESCRIPTION OF THE INVENTION  
       [0035]     Looking at  FIG. 1 , there is shown a shank type seed drill apparatus  10  having a central portion  14  and having a left wing portion  16  having two frames  20 . The apparatus  10  has a right wing portion (not shown) that is a mirror image of the left wing portion  16 . The left wing portion  16  may be upwardly folded for transport using arm  18 . Likewise, the right wing portion may be upwardly folded for transport. Each frame  20  includes a forward frame section  30  with tillers  12  and a rearward frame section  40  with tillers  12 . The apparatus  10  is connected to a tractor in a conventional manner and has an axis A in a direction of movement of the apparatus  10  when tilling a field.  
         [0036]     In  FIGS. 2 and 3 , there is shown one frame  20  of the apparatus  10 , with the tillers removed for clarity. The forward frame section  30  includes a front transverse tube  31  and a rear transverse tube  32  connected by supports  33 . Angled frame members  35  and  36  are connected to the top of the front transverse tube  31  and the rear transverse tube  32  to form the forward frame section  30 .  
         [0037]     The forward frame section  30  also features lugs  38  at the front end for mounting to a rockshaft  24 , which in turn is mounted to boom  22 , so that motion of a hydraulic cylinder  26  rotates the rockshaft  24  resulting in vertical elevation change of the frame  20 . A link  27  is attached to a lever  28  on the rockshaft  24  to translate motion of press wheel gangs  50 ,  57 ,  64  at rear (which are described below) so this vertical motion is parallel with the ground and synchronized front to rear. A journal  39  at the rear of the triangle formed by the forward frame section  30  is oriented horizontally and parallel to the direction of travel. The mount for the hydraulic cylinder actuator  26  is positioned near the vortex of the triangle.  
         [0038]     The rearward frame section  40  includes a front transverse tube  41  and a rear transverse tube  42  connected by supports  43 . It can be seen that the front transverse tube  31 , the rear transverse tube  32 , the front transverse tube  41  and the rear transverse tube  42  are constructed in two sets to mount ground-working tools (such as tillers  12 ) in typical staggered configuration. The rearward frame section  40  attaches to the forward frame section  30  on the journal  39  so it can rotate relative to the forward frame section  30  in radial directions R 1  (see  FIG. 3 ) approximately 10 degrees in either direction.  
         [0039]     Links  37  attach pivotally to lugs on both the forward frame section  30  and the rearward frame section  40 . As the apparatus  10  is working, draft loads are carried through these links  37  as well as through the thrust surfaces of the connecting journal  39 . The action of the forward frame section  30  and the rearward frame section  40  is not dependent on these links  37 ; they are present as a stabilizer and companion draft link.  
         [0040]     Referring to  FIG. 3 , press wheel gangs  50 ,  57 ,  64  are connected to the rearward frame section  40  by crossbar  44  and bars  45 ,  46  and  47 , which pivot about journals  54 ,  61 ,  68  on rear transverse tube  42 , when actuated by the rockshaft  24 . Crossbar  44  has an axis B in direction of movement of the apparatus in a field. As even contact with the soil is necessary for successful planting, a section of this size includes three separate press wheel gangs. Left outer press wheel gang  50  includes mounting arm  51  and press wheels  53  suspended from the mounting arm  51  by mounting brackets  52 . Middle press wheel gang  57  includes mounting arm  58  and press wheels  60  suspended from the mounting arm  58  by mounting brackets  59 . Right outer press wheel gang  64  includes mounting arm  65  and press wheels  57  suspended from the mounting arm  65  by mounting brackets  66 .  
         [0041]     Mounting arms  51  and  65  are attached to the crossbar  44  at pivot journals  55  and  68  respectively so the outer press wheel gangs  50  and  64  can oscillate about these journals  55  and  68  in radial directions R 2  shown in  FIG. 5 . Outer press wheel gangs  50  and  64  set the vertical elevation of the rearward frame section  40  and the pitch in radial directions R 1  of the front transverse tube  41  and the rear transverse tube  42  of the rearward frame section  40  as the crossbar  44  stays parallel with the front transverse tube  41  and the rear transverse tube  42  of the rearward frame section  40  following the contour of the field. The middle press wheel gang  57  oscillates about a journal  71  similar to the outer press wheel gangs  50  and  64 . At the same time, the pitch of the forward frame section  30  and the rearward frame section  40  is controlled by the forward frame section  30  following the contour of the field encountered by land wheels  29  castering under the boom  22  (see  FIG. 1 ) and the rearward frame section  40  following the contour of the field under the outer press wheel gangs  50  and  64 .  
         [0042]     Turning now to  FIG. 4 , there is shown a mechanism by which the middle press wheel gang  57  may move vertically in directions R 3  in order to maintain contact with the soil, while maintaining its share of the total weight carried by the press wheels and cross bar  44 . Specifically, there is provided a parallel arm linkage assembly indicated generally at  70 . Weldment  72  is journalled to crossbar  44  with pins  73  (the left pin not being shown). Compression strut  74  applies pressure through pin  75 , causing weldment  72  to rotate and apply downward pressure to packer mount journal housing  76  through pin  77 . In journal housing  76 , pin  80  mounts a sleeve  81  that is arranged in hole  82  in mounting arm  58 . The distance between pin  73  and  75  centerlines can be varied by adjusting bolt  79 , so that middle press wheel gang  57  can receive its correct share of the total packer load regardless of its width (at times it is not exactly ⅓ of the total press wheel set width, depending on spacing configurations). The relationship of the distance between pins  73  and  75  and pins  73  and  77  is such that the majority of the thrust load from strut  74  results in a vertical load on the press wheel frame, while a proportionate amount is applied the middle press wheel gang  57  throughout its allowed vertical travel.  FIGS. 5 and 6  show the wheel gangs  50 ,  57  and  64  at their extremes of vertical travel.  
         [0043]     A further feature of the apparatus  10  is the adjustable weight transfer device  86  shown in  FIGS. 7 and 8 . There is shown a side view of the support  33  and the front transverse tube  31  of the forward frame section  30 , which is connected to the boom  22  by rockshaft  24 . The rockshaft  24  is connected to the boom  22  at journal  87 , and the forward frame section  30  is connected to the rockshaft  24  at journal  88 , so retraction of the cylinder  26  results in lowering the forward frame section  30  from its upward position as shown in  FIG. 7  to its working position as shown in  FIG. 8 .  
         [0044]     The apparatus  10  has a heavy boom  22 . At times, it is advantageous to apply heavy packing pressure to the press wheels  53 ,  60 ,  67 , so the device  86  is used to transfer the weight of the boom  22  to the rear press wheel gangs  50 ,  57  and  64 . This is done by creating a link that induces a high lateral force between journal  89  on boom flange  90  and pivot pin  91  that is connected to the forward frame section  30 . As rockshaft  24  lowers forward frame section  30  to its working position, linkage  92  and linkage  93  approach but do not reach alignment.  
         [0045]     A spring assembly  94 , which serves as a biasing means and includes spring  106 , is mounted at its lower end  102  by pin  96  to a lug  34  that is attached to the front transverse tube  31  of the forward frame section  30 . Bolt  104  extends through the spring assembly  94 . A flange  101  extends downward from linkage  93  and is journaled by pivot pin  95  to the lower end  102  of the spring assembly  94 . The spring  106  exerts a growing pressure on linkage  93  by way of pivot pin  95  and flange  101  as rockshaft  24  lowers forward frame section  30  to its working position. This downward spring pressure translates to a high net lateral force through flange  90  and pivot pin  91 . As a result, the left wing section  16  tries to rotate about journal  87  on the boom  22 . This force in turn applies weight to the hitch of the tractor and to the press wheels  53 ,  60  and  67 .  
         [0046]     To adjust the amount of force, the length of spring  106  can be changed with adjustment nut  97  on top of compression plate  111 , stopped bolt  98  can be adjusted, or the relationship of the linkages  92  and  93  can be lowered to close to parallel as this ratio determines the lateral force component. A stop is also provided to limit the linkage of going into a locking position as this could cause damage when the wing is raised out of working position. The linkage is arranged so that the force diminishes when raising the apparatus at headlands, going to zero when winging up for transports, and does not cause any extra loading on the rockshaft, while providing the operator with a range of adjustment to optimize the packing pressure of the apparatus.  
         [0047]     Therefore, the present invention provides a tillage apparatus that provides improved frame flexibility such that the rear press wheels can more closely follow the contours of the ground, that provides improved weight distribution for the rear press wheels, and that provides adjustable weight transfer to the rear press wheels. The tillage apparatus thereby provides for more even seed insertion and soil compaction.  
         [0048]     Although the present invention has been described in detail with reference to certain embodiments, one skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which have been presented for purposes of illustration and not of limitation. Therefore, the scope of the appended claims should not be limited to the description of the embodiments contained herein.