Abstract:
An agricultural implement including a pair of support members and a pivot assembly coupled between the support members. The pivot assembly includes at least one resilient bushing and a side-play restraint system. The resilient bushing being in contact with a portion of the restraint system.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a non-provisional application based upon U.S. provisional patent application Ser. No. 61/901,097 entitled “AGRICULTURAL TANDEM PIVOT ASSEMBLY”, filed Nov. 7, 2013, which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to agricultural implements, and, more particularly, to a resilient bearing assembly used with a walking tandem axle on an agricultural implement. 
     2. Description of the Related Art 
     Farmers utilize a wide variety of tillage implements to prepare soil for planting. Some such implements include two or more sections coupled together to perform multiple functions as they are pulled through fields by a tractor. For example, a field cultivator is capable of simultaneously tilling soil and leveling the tilled soil in preparation for planting. A field cultivator has a frame that carries a number of cultivator shanks with shovels at their lower ends for tilling the soil. The field cultivator converts compacted soil into a level seedbed with a consistent depth for providing excellent conditions for planting of a crop. Grass or residual crop material disposed on top of the soil is also worked into the seedbed so that it does not interfere with a seeding implement subsequently passing through the seedbed. The depth of the implement is controlled by a system that uses wheels carried by a pivoting axle assembly. 
     The axle assembly may be in the form of a walking beam assembly, simply called a walking axle, or a walking tandem assembly. The walking tandem assembly includes two axles for wheels with a pivoting coupling located between the axles. The pivoting coupling is connected to a support structure of the implement, which transfers some of the weight of the implement to the wheels coupled to the axles. 
     The prior art pivoting couplings use tapered roller bearings, which require greasing and which have undesirable failure modes, such as, brinelling, contamination, and are subject to improper bearing setting. 
     What is needed in the art is a bearing assembly that can eliminate the need for tapered rolling bearings and their associated failure modes. And to make the assembly less prone to failure. 
     SUMMARY OF THE INVENTION 
     The present invention provides a tillage implement with walking tandem axle assemblies having resilient bearings and a side play restraint system. 
     The invention in one form is directed to an agricultural implement including a pair of support members and a pivot assembly coupled between the support members. The pivot assembly includes at least one resilient bushing and a side-play restraint system. The resilient bushing being in contact with a portion of the restraint system. 
     The invention in another form is directed to a pivot assembly for use with an agricultural implement having a pair of support members. The pivot assembly is coupled between the support members. The pivot assembly includes at least one resilient bushing and a side-play restraint system. The resilient bushing being in contact with a portion of the restraint system. 
     The invention in another form is directed to a method of securing a pivot assembly to support members of an agricultural implement including the steps of carrying at least one resilient bushing on a side play restraint system; and rigidly coupling the support members to the side play restraint system. 
     An advantage of the present invention is that it extends the life of the pivoting assembly. 
     Another advantage of the present invention is that it is applicable to a large number of tillage equipment platforms. 
     Yet another advantage is that the present invention can be applied to legacy equipment, thereby reducing retrofit costs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of an agricultural implement using an embodiment of a tandem axle assembly of the present invention; 
         FIG. 2  is a partially sectioned view of an embodiment of a pivot assembly used in the tandem axle assembly of  FIG. 1 ; 
         FIG. 3  is a partially sectioned view of another embodiment of a pivot assembly used in the tandem axle assembly of  FIG. 1 ; 
         FIG. 4  is a partially sectioned view of yet another embodiment of a pivot assembly used in the tandem axle assembly of  FIG. 1 ; and 
         FIG. 5  is a schematical representation of the agricultural implement presented in  FIG. 1 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate some embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and more particularly to  FIGS. 1 and 5 , there is shown an embodiment of a tillage implement  10  of the present invention, mainly shown in abstract as a block combined with details of the present invention. Tillage implement  10  includes a walking tandem axle assembly  12  connected to a support assembly  14  of implement  10 . Support assembly  14  is part of tillage implement  10  that is towed by a traction unit, such as by an agricultural tractor (not shown). Support assembly  14  has support members  16  and  18  that extend downward and connect to walking tandem axle assembly  12 . 
     Walking tandem axle assembly  12  includes a wheel axle  20 , a wheel axle  22  and a pivot assembly  24 . The axes of axles  20  and  22  and the axis of pivot assembly  24  may be substantially parallel. A structural member  26  serves as a housing  26  for elements of pivot assembly  24 . Three embodiments of pivot assembly  24  are separately illustrated in  FIGS. 2-4 , with the pivot assembly of  FIG. 3  being designated as pivot assembly  50 , for the sake of distinguishing between the embodiments.  FIG. 4  is a variation of the embodiment illustrated in  FIG. 2 . Each embodiment has a side play restraint system that is composed of a series of parts identified herebelow. 
     Pivot assembly  24  includes housing  26 , a flag pin  28 , a spacer plate  30 , a nut  32 , bushings  34 , and thrust washers  36 . A bolt  38  extends through a flag  40  of flag pin  28 . Flag pin also includes a shoulder  42 . Bushings  34  have a seal  44  to seal the bushings from moisture and from abrasive particles. Spacer plate  30  is secured to support member  18  and may be welded thereto. During assembly flag pin  28  is inserted through a hole in support member  16 , a thrust washer  36 , bearings  34  (positioned in housing  26 ), another thrust washer  36 , and support member  18 . Nut  32  is threaded onto an end of flag pin  28  drawing shoulder  42  against a part of spacer plate  30  to thereby rigidly affix an end of flag pin  28  to support member  18 . Bolt  38  is threaded into a threaded opening in support member  16 , thereby rigidly affixing flag pin  28  to support member  16 . This construct effects a rigidly defined spacing between support members  16  and  18 , thereby allowing housing  24  to have some lateral movement along flag pin  28 . The side play restraint system of this embodiment includes flag pin  28 , plate  30 , nut  32 , and bolt  38 , and of course relies on the presence of flag  40  and shoulder  42 . 
     Pivot assembly  50  includes housing  52 , a bolt  54 , a nut  56 , a key  58 , sleeve  60  and bushings  62 . Bushings  62  similar to bushings  34  may have a seal to seal the bushings from moisture and from abrasive particles. During assembly bolt  54  is inserted through a hole in support member  18 , sleeve  60 , a hole in support member  16 , and key  58  is inserted into a keyway, allowing key  58  to extend into a recess in sleeve  60 . Nut  56  is threaded onto an end of bolt  54  drawing support members  16  and  18  against opposite ends of sleeve  60  to thereby rigidly affix both support member  16  and support member  18  together. This construct effects a rigidly defined spacing between support members  16  and  18 , thereby allowing housing  52  to have some lateral movement along bolt  54 . Thrust washers  36  of the previous embodiment may be used in this embodiment as well, and are optional in the previous embodiment. The side play restraint system of this embodiment includes bolt  54 , nut  56 , and sleeve  60 , and of course relies on the presence of key  58  and a corresponding keyway and recess in sleeve  60 . 
     Key  58  and the keyway in support member  16  along with the recess in sleeve  60  serve to prevent sleeve  60  from rotating about bolt  54 . A feature of the second embodiment is that sleeve  60  allows the bearing surface of bushings  62  to have a larger internal diameter, which results in a larger bearing surface to carry larger loads. 
     In  FIG. 4  there is illustrated an embodiment of the present invention similar to the one illustrated in  FIG. 2 , with a housing  126  and flange bushings  134  as the different elements. Flange bushings  134  replace the combination of bushings  34 , thrust washers  36  and seals  44 . 
     An advantage of the present invention is that it extends the life of the bearing. Another advantage is that the present invention is applicable to a large number of tillage equipment platforms. Yet another advantage is that the present invention is easily applied to legacy equipment, thereby reducing retrofit costs. 
     While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.