Abstract:
A pivot assembly is provided for attaching a closing wheel frame to a planter. The closing wheel frame has a pair of closing wheels attached at a rear end and a pair of mounting openings formed at a front end. The pivot assembly includes ball bearings having outer races fit loosely within each of the mounting openings of the closing wheel frame. The inner races of the ball bearings are secured to the planter frame using threaded nut and bolt assemblies. The closing wheel frame is pivotal relative to the planter frame during normal operation by relative movement between the inner and outer races of the bearing. Variations of the mounting openings in the closing wheel frame are disclosed, including a tubular part, heavy washer or other annular structure welded to an outside surface of the closing wheel frame, or a bearing housing formed integral with the closing wheel frame.

Description:
RELATED APPLICATIONS  
       [0001]    The Applicant claims priority under 35 U.S.C. §119( e ) of provisional U.S. Patent Application Serial No. 60/379,380 filed on May 8, 2002. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates generally to closing wheel assemblies for agricultural planters. In particular, the present invention relates to improved pivot assemblies for mounting closing wheel frames to planters.  
           [0004]    2. Description of the Prior Art  
           [0005]    The first “modern” planter was the John Deere 7000 series planter introduced in 1973. This planter is depicted in FIGS. 1, 2 and  3  of the accompanying drawings. This design utilized two opener disks  11  which contact at one point  12  and diverge at a small angle to form a furrow  13  in the ground. The depth of the furrow is determined by the adjustable position of the gauge wheels  14 . The seed is dropped into a seed tube  15  and falls into the furrow  13 .  
           [0006]    A pair of closing wheels  16 , which are mounted at an angle and are spring loaded to exert a downward force on the ground, then close the furrow  13  thereby covering the seed with soil. The closing wheels  16  are supported by a closing wheel frame  17 . The closing wheel frame  17  was constructed from 0.164″ thick sheet metal for many years until the introduction of the John Deere  1700  series planter.  
           [0007]    The closing wheel frame  17  on the original John Deere  7000  series planter was attached to the shank assembly  18  at a pivot point  19 . The pivot point  19  on each side of the closing wheel frame  17  consisted of a heat-treated 0.750″ diameter bushing  20  (FIG. 3) clamped to the shank assembly  18  and the support casting  21  by a bolt  29  going through holes  22  in the shank assembly  18  and support casting  21 . The outer bearing surface was a slightly larger than 0.750″ hole  23  in the sheet metal of the closing wheel frame  17 .  
           [0008]    Down pressure for the closing wheels  16  was provided by an extension spring attached at  24  to the support casting  21 . The spring pressure was adjusted by a bolt  25 . Because the moment arm  26  of the spring about the pivot point  19  was small relative to the moment arm  27  of the wheel reaction  28 , the spring pressure was necessarily large. This resulted in high pressure on the bearing surfaces of the bushing  20  and the sheet metal hole  23 , which in turn resulted in accelerated wear on both the bushing  20  and the hole  23 .  
           [0009]    Uneven wear on those components resulted in the closing wheels  16  pulling to one side and prevented them from closing the furrow  13  adequately. To alleviate this problem, John Deere increased the size of the bushing  20  to 1.00″ and changed the holes  22  to horizontal slots to allow the frame  17  to be adjusted to center the closing wheels  16  on the furrow  13 . The slots were ineffective because by the time adjustment was needed, the parts obviously were worn which made it impossible to accurately relocate the bushings.  
           [0010]    John Deere remedied this situation when they introduced the Model 7200 series planter in 1984. The bearing surface was increased to 1.562″ diameter, and a cam was introduced on the right-hand side. To accommodate these changes the new support casting was attached with two vertical bolts that go through holes in the top of the casting. The above changes did not adequately alleviate the problem and in 1992 John Deere changed the rear hole in the top of the support casting to a lateral slot to allow more adjustment.  
           [0011]    With the introduction of the Model 1700 series planters, John Deere improved the closing wheel frame pivot by increasing the frame bearing surface to 0.25″ width and making it a casting. However, the thicker bearing surface and using steel on cast iron has not proven to be a major improvement over the earlier design.  
           [0012]    Other manufacturers have experienced wear problems at the closing wheel frame pivot similar to John Deere but have basically stayed with a steel on steel bearing surface and have provided cams for adjustment. Several after-market repair kits have been available in recent years. Montezuma Welding and R K Products Inc. have provided a heat treated 0.250″ thick outer bearing surface along with heat treated cams. May-Wes Manufacturing Inc. markets a bushing kit (PERMA-FIXTM) that provides a substantial wear surface as well as the means for lubrication. A&amp;T Enterprises offers a repair kit (PRESS FIX™) that utilizes ball bearings mounted in conventional “flangette” mountings. The flangette mountings allow for misalignment and still allow the bearing outer race to be clamped tightly. The bearing used has a 1.00″ diameter bore that permits the use of a cam adjuster.  
         SUMMARY OF THE INVENTION  
         [0013]    The present invention provides two uniquely simple and effective applications of a ball bearing to provide an economical and very durable pivot between the closing wheel frame and the planter frame on several planters that have been manufactured since 1973. The majority of these planters have been manufactured by John Deere or Kinze Manufacturing.  
           [0014]    A first embodiment utilizes a simple tubular part as a housing for the ball bearing. The steel tubular housing is welded to the outside surface of the closing wheel frames, which are constructed from sheet metal. The tubular housing provides a mounting surface that loosely receives the outer race of the ball bearing. The tubular housing also permits the alternative use of a cam that can be applied interchangeably with the ball bearing.  
           [0015]    A second embodiment utilizes a heavy steel washer welded to the outside surface of the cast closing wheel frame of John Deere Model 1700 series planters. The inside diameter of the washer is essentially the same as that of the frame opening. The inside surface of the washer and the inside surface of the frame opening serve together as a housing for the ball bearing.  
           [0016]    The present invention provides the following advantages:  
           [0017]    1. Allows use of a small, popular, economical and durable ball bearing.  
           [0018]    2. Provides a simple and economical mounting for the ball bearing.  
           [0019]    3. Utilizes the fact that several models of planters have adjustment features that can be used effectively with this design. Adjustment is occasionally necessary to compensate for damage and manufacturing variation.  
           [0020]    4. Provides an interchangeable cam alternative to the ball bearing for those planter models that have no adjustment features but need to be adjusted.  
           [0021]    5. The ease of interchangeability between the ball bearing and cam makes it practical to initially use cams on those planter models that have no adjustment features but need adjustment and later upgrade to the more durable ball bearings when time is available to correct the problem. This might be done by repairing the row unit or by relocating one of the bearing housings on the closing wheel frame.  
           [0022]    6. The design of the second embodiment could be easily incorporated into future planters equipped with cast closing wheel frames. By making the cast closing wheel frame approximately 0.25″ thicker in the pivot area, an excellent bearing housing would be provided. No change in the machined diameter of the frame opening would be necessary.  
           [0023]    7. The design of the third and fourth embodiments could be easily incorporated into future planters equipped with sheet metal closing wheel frames. In these embodiments, a tubular bearing housing is formed integral in the sheet metal closing wheel frame for receiving the outer race of a ball bearing.  
           [0024]    8. The pivot assemblies are easy to install and require very little time in comparison to conventional ball bearing assemblies.  
           [0025]    9. Where ball bearings are used, wear and related maintenance is practically eliminated.  
           [0026]    Numerous other objects of the present invention will be apparent to those skilled in this art from the following description wherein there is shown and described two preferred embodiments of the present invention, simply by way of illustration of some of the modes best suited to carry out the invention. As will be realized, the invention is capable of other different embodiments, and its several details are capable of modification in various obvious aspects without departing from the invention. Accordingly, the drawings and description should be regarded as illustrative in nature and not restrictive. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0027]    The present invention will become more clearly appreciated as the disclosure of the invention is made with reference to the accompanying drawings. In the drawings:  
         [0028]    [0028]FIG. 1 is a side view of a planter unit and closing wheel assembly of a conventional agricultural planter.  
         [0029]    [0029]FIG. 2 is a rear view of the closing wheel assembly of the conventional planter shown in FIG. 1.  
         [0030]    [0030]FIG. 3 is an exploded perspective view of a conventional pivot assembly for the closing wheel frame of the conventional planter shown in FIG. 1.  
         [0031]    [0031]FIG. 4 is an exploded perspective view of a pivot assembly for a closing wheel frame according to a first embodiment of the present invention.  
         [0032]    [0032]FIG. 5 is an exploded perspective view of a pivot assembly for a closing wheel frame according to a second embodiment of the present invention.  
         [0033]    [0033]FIG. 6 is a cross section view of a frame opening formed in a sheet metal closing wheel frame according to a third embodiment of the present invention.  
         [0034]    [0034]FIG. 7 is a cross section view of a frame opening formed in a sheet metal closing wheel frame according to a fourth embodiment of the present invention.  
         [0035]    [0035]FIG. 8 is an exploded perspective view of a support casting and pivot assembly for a closing wheel frame according to a fifth embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0036]    A closing wheel frame pivot assembly according to the first embodiment of the present invention will now be described with reference to FIG. 4 of the accompanying drawings. It should be noted that only the left hand parts of a complete pivot assembly are shown in the drawing. An identical set of parts is provided on the right side of the pivot assembly.  
         [0037]    The first embodiment permits the use of a small, economical and very durable ball bearing  31  as a pivot for the closing wheel frame on most planters. The ball bearing  31  is mounted in a very unconventional manner. The bearing housing  32  is an annular structure in the form of a simple steel tubular part welded to the outside surface of planter closing wheel frames  33 , which are made from sheet metal. The housing  32  is machined to provide approximately 0.005″ to 0.040″, and preferably about 0.015″, clearance between the inner surface of the housing  32  and the outside surface of the outer race of the bearing  31 . Such clearance provides a loose fit of the outer race within the housing  32  and allows for misalignment.  
         [0038]    The inside surface of the inner race of the bearing  31  is clamped to the planter shank assembly  18  and/or the support casting  21  with a carriage bolt  34  and a nut  35 . A clip (not shown) can be used to adapt the carriage bolt head and neck to the support casting  21  in some cases. Several 1″ outside diameter flat washers  36  position the bearing  31  approximately in the center of the bearing housing  32 . After the installation is complete, a thread deforming locking jam nut  37  is installed and tightened against the regular nut  35 . On planters that originally had a 0.75″ or 1.00″ hole in the frame to serve as the outer bearing surface, the worn bole must be enlarged. This is to provide clearance between the flat washers  36  and the hole in the frame  33 .  
         [0039]    It should be noted that even if the ball bearing  31  would fail and lock up, the housing  32  would slip on the outer race of the bearing  31 . This loose fit of the outer race of the bearing  31  within the housing  32  provides an excellent secondary pivot in case the primary pivot between the inner and outer races of the ball bearing  31  fails.  
         [0040]    [0040]FIG. 4 also shows a new type of cam  38  that can be used interchangeably with the ball bearing  31 . The cam  38  can be used to provide an adjustment when necessary to keep the closing wheels aligned properly. The outside diameter of the cam  38  is approximately 0.030″ to 0.050″, and preferably about 0.040″, less than the inside diameter of the housing  32 . This clearance permits adequate misalignment between the cam  38  and housing  32  to avoid putting the cam  38  in a bind when the cam  38  is adjusted.  
         [0041]    The cam  38  is made from steel and is heat treated. The bolt hole is drilled off center, preferably by about 0.150″. The cam adjustment is provided by rotating the cam  38  about the bolt  34 . The cam  38  has several features that make it uniquely different from cams used in similar applications in the past. Other cams have a rectangular or hex boss to accept a wrench to be used for adjustment. In contrast, the Applicant&#39;s cam  38  shown in FIG. 4 has a milled slot  39  that accepts a screw driver for adjustment. Other cams have an unnecessary shoulder at the outer end of their bearing surface. The purpose of this is presumably to prevent the outer bearing surface of the frame from slipping off of the cam. The Applicant&#39;s cam  38  shown in FIG. 4 has no such shoulder. Because of the two features mentioned above, the length of the bearing surface provided by the cam  38  has been increased to approximately twice that of other conventional cams while actually shortening the overall length.  
         [0042]    A closing wheel frame pivot assembly according to the second embodiment of the present invention will now be described with reference to FIG. 5 of the accompanying drawings.  
         [0043]    [0043]FIG. 5 shows the ball bearing  31  as it is applied to a John Deere Model 1700 series planter according to the Applicant&#39;s invention. In this case, an annular structure in the form of a heavy metal washer  41 , e.g., a 1.562 I.D.×2.19 O.D.×0.250″ thick washer, is welded to the outside surface of the cast closing wheel frame  42 . The 0.250″ thick cast material of the closing wheel frame  42  and the heavy washer  41  together make an excellent bearing housing. The tubular housing  32  shown in FIG. 4 could be used with the cast closing wheel frame  42 , but the heavy washer  41  is more desirable. When the washer  41  is welded to the outer surface of a worn cast frame  42 , the washer  41  may contact the bearing  31  only at the outer end. This is acceptable in this lightly loaded application. It should be noted that the bearing  31  could be used on new John Deere Model 1700 series planters in place of the current pivot parts without the heavy washer  41 , but the appearance would be unusual. A more desirable approach to incorporate the Applicant&#39;s invention into new John Deere planters would be to increase the thickness of the casting of the cast frame  42  around the bearing  31 , e.g., by 0.250″.  
         [0044]    Closing wheel frame pivot assemblies according to the third and fourth embodiments of the present invention will now be described with reference to FIGS. 6 and 7 of the accompanying drawings.  
         [0045]    The third and fourth embodiments of the present invention provide integral designs that can be incorporated into future planters having sheet metal closing wheel frames. In these integral designs, the tubular bearing housings  32  shown in FIG. 4 are replaced with bearing housings  32   a ,  32   b  that are formed integrally in the sheet metal frames  33   a ,  33   b.    
         [0046]    In FIG. 6, the bearing housing  32   a  is formed integral with the sheet metal closing wheel frame  33   a  and has an inside diameter which is slightly smaller at its center and flared at its ends. This flared configuration allows a closer fit between the housing  32   a  and a cylindrical bearing  31   a , while allowing the bearing  31   a  to pivot slightly within the housing  32   a  for alignment.  
         [0047]    In FIG. 7, the bearing housing  32   b  is formed integral with the sheet metal closing wheel frame  33   b  and has a generally cylindrical inside diameter. The outer surface of the outer race of the ball bearing  31   b  is spherical to facilitate alignment of the bearing  31   b  with the bolt and other parts of the closing wheel frame as described above.  
         [0048]    In the embodiments of FIGS. 6 and 7, the outer surface of the bearings  31   a ,  31   b  fit within the integral bearing housings with a loose fit. However, since either the inner surface of the bearing housing ( 32   a  in FIG. 6) or the outside surface of the outer race of the bearing ( 31   b  in FIG. 7) are curved, a closer fit, e.g., 0.005″ clearance, can be provided between the bearing  31   a ,  31   b  and the housing  32   a ,  32   b  while still allowing the bearing to pivot slightly for alignment.  
         [0049]    A closing wheel frame pivot assembly according to a fifth embodiment of the present invention will now be described with reference to FIG. 8 of the drawings. In FIG. 8, a support casting  50  and pivot assembly  51  for attaching a closing wheel frame  52  to a planter are shown. The support casting  50  shown in FIG. 8 is similar to the later (1992 and up) John Deere Model 7200 series planters and allows adjustment of the support casting  50  relative to the shank assembly (not shown) of the planter frame. The support casting  50  is attached to the shank assembly of the planter frame by two vertical bolts  53 ,  54 . The adjustment is provided by a lateral slot  55  in the top of the support casting  50  for the rear bolt  53 . The front bolt  54  passes through a round hole  56  in the top of the support casting  50 . This arrangement allows the support casting  50  to be pivoted laterally without loosening the bolts  57  that clamp the bearings  58  to the sides of the support casting  50 . The lateral adjustment provided by the lateral slot  55  minimizes or eliminates the possibility of misalignment between the ball bearings  58 .  
         [0050]    The ball bearings  58  are located by holes  59  in the sides of the support casting  50  and bolted in place within the respective bearing housings  60  of the cast closing wheel frame  52  using carriage bolts  57 . The bearing housings  60  are formed integrally in the cast closing wheel frame  52  and have a width that corresponds to the width of the ball bearings  58 . As in the embodiments described above, flat washers  62 ,  63  are used to position the ball bearings  58  approximately in the center of the bearing housings  60 , threaded nuts  64  cooperate with the threaded bolts  57  to secure the inner races of the bearings  58  to the support casting  50 , and threaded locking jam nuts  65  are used to keep the threaded nuts  64  locked in place. With this arrangement, the ball bearings  58  remain aligned with each other during lateral adjustment of the closing wheel frame  52 , and a tighter fit between the bearings  58  and housings  60  is possible. However, a fairly loose fit is still desirable to facilitate removal of the bearings  58  from the housings  60  and to provide a secondary pivot in case the ball bearing  58  fails.  
         [0051]    While the invention has been specifically described in connection with specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and the scope of the appended claims should be construed as broadly as the prior art will permit.