Abstract:
The ground wheels of a round baler are mounted on the chassis of the baler using a suspension system wherein a rigid axle of the system is spaced forwardly in offset relationship to spindles that journal the wheels for rotation. Fore-and-aft arms that connect the wheels with the axle are pivotally coupled with the axle in an independent manner so that each wheel can swing up and down relative to the chassis independently of the other wheel. Resilient cushion structure associated with the axle yieldably resists upward swinging of the wheel arms to thereby cushion the baler against jarring shock loads caused by abrupt terrain changes.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to round balers and, more particularly, to a way of providing a suspension system for such balers so as to cushion the machines against shock loads encountered during field operations and travel along roadways. 
       BACKGROUND AND SUMMARY 
       [0002]    Conventional round balers are typically provided with fixed, transverse axles that pass below the baling chamber and bolt solidly to the chassis. Thus, as the baler is being towed in the field or along the road, it is subject to jarring impact loads as the ground wheels encounter abrupt changes in the terrain. This can be damaging to the equipment and physically demanding on the operator. 
         [0003]    It would be desirable to provide a suspension system between the chassis and axle such that the wheel and axle assembly is essentially spring-loaded to cushion the baler against abrupt terrain changes. However, there are space and dimensional challenges to simply spring-loading the axle assembly that have heretofore not been overcome. For example, one challenge resides in the fact that the suspension system must not impede ejection of the finished bale from the baling chamber when the tailgate is raised and the bale falls out of the chamber by gravity. 
         [0004]    Accordingly, an important object of the present invention is to provide an axle suspension system on a round baler that provides the desired cushioning support for the chassis and other portions of the baler without impeding ejection of a bale from the chamber when the tailgate is raised at the end of a baling cycle. It is also important and desirable to achieve a satisfactory suspension system that permits the ground wheels to remain rearward of the center of gravity of the baler when the bale is full-size, e.g., rearward of the center of the full-size baling chamber so as to optimize load distribution. 
         [0005]    In achieving these objectives, the present invention contemplates an arrangement in which the load-supporting ground wheels are rotatable about axes of rotation disposed rearwardly of the fore-and-aft center of the baling chamber. However, instead of having a suspended axle that defines those axes of rotation, and which would interfere with the bale as it ejects from the baler, the present invention contemplates having a rigid, transverse axle that is spaced or offset forwardly from the axes of rotation of the wheels while permitting the wheels to have cushioned up and down swinging movement relative to the fixed axle. Offsetting the axle from the wheel rotation axes in this way clears space between the wheels for the ejecting bale to fall to the ground. 
         [0006]    The two wheels are rotatably supported on relatively short spindles that are, in turn, supported by forwardly extending wheel arms pivotally coupled at their front ends with the rigid axle. The axle is tubular and rotatably receives shafts fixed to the front ends of the wheel arms such that the shafts rotate within the axle as the wheel arms and wheels swing up and down. Resilient cushions strategically located within the axle engage the shafts so as to yieldably resist rotation of the shafts in a direction corresponding to upward swinging of the wheel arms and the wheels. Each wheel is mounted independently of the other so as to provide independent suspension of the two wheels. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a left, rear isometric view of a baler employing a suspension axle system in accordance with the principles of the present invention, the left ground wheel being shown in phantom and portions of the kicker assembly (it moves the ejected bale rearwardly to provide clearance for reclosing the tailgate) being broken away to reveal details of construction; 
           [0008]      FIG. 2  is an enlarged, fragmentary isometric view of the baler of  FIG. 1  illustrating details of construction; 
           [0009]      FIG. 3  is a longitudinal, vertical cross sectional view through the baler illustrating a full size bale in the baling chamber prior to ejection; 
           [0010]      FIG. 4  is an enlarged, fragmentary cross sectional view similar to  FIG. 3  but on a larger scale to reveal details of construction of the suspension axle system; 
           [0011]      FIG. 5  is a vertical cross sectional view through the baler similar to  FIG. 3  but illustrating the tailgate raised and the finished bale sitting on the ground immediately following ejection; 
           [0012]      FIG. 6  is an exploded isometric view of one embodiment of a suspension axle system in accordance with the present invention; 
           [0013]      FIG. 7  is an enlarged, schematic cross-sectional view of one end of the suspension axle taken substantially along line  7 - 7  of  FIG. 6 , the system being illustrated in an essentially no-load position wherein the wheels are essentially fully lowered relative to the axle; 
           [0014]      FIG. 8  is a cross-sectional view of the suspension axle similar to  FIG. 7  but illustrating the wheel arm in a nominal position under partial loading; 
           [0015]      FIG. 9  is a cross-sectional view of the suspension axle similar to  FIGS. 7 and 8  but illustrating the wheel arm in the highest (extreme shock) position; 
           [0016]      FIG. 10  is a fragmentary cross-sectional view of a prior art baler having a fixed, forwardly offset axle; and 
           [0017]      FIG. 11  is a fragmentary left rear isometric view of the prior art baler of  FIG. 10 . 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    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. 
         [0019]    The baler  10  of  FIGS. 1-9  has a chassis broadly denoted by the numeral  12  that is supported by a pair of left and right ground wheels  14 ,  16  for travel across the field and along roads and highways. A tongue  18  projecting forwardly from chassis  12  adapts baler  10  for connection to a towing tractor (not shown). 
         [0020]    As well understood by those skilled in the art, baler  10  includes a pair of opposite side panels  20  and  22  that cooperate with a multiplicity of transversely extending rollers  24  and belts  26  to define an internal baling chamber  28 . In the illustrated embodiment, baling chamber  28  is a variable-size chamber wherein the chamber is relatively small at the beginning of a baling cycle and then progressively enlarges as the cycle continues until reaching a full size condition as illustrated in  FIG. 3  wherein a full size bale  30  is disposed therein. Belts  28  are maintained under tension during the baling cycle and are driven in such a direction that bale  30  rotates in a counterclockwise direction viewing  FIG. 3  during the cycle, thus causing the bale to be compacted as it turns and as additional crop material is introduced into chamber  28  throughout the cycle. The particular structure used to define chamber  28  is of no consequence insofar as the principles of the present invention are concerned, and chamber  28  could be a fixed-size chamber without departing from the principles of the present invention. 
         [0021]    Rear portions of the side panels  20 ,  22  and belts  26  define a tailgate  32  that may be raised as illustrated in  FIG. 5  to open chamber  28  at the completion of a baling cycle for the purpose of ejecting the bale  30  therefrom. With tailgate  32  raised, there is nothing to retain the bale within chamber  28 , and the bale simply drops out of the opened chamber onto the ground, whereupon a conventional kicker  34  may be actuated to engage bale  30  and move it rearwardly a sufficient extent to permit tailgate  32  to be closed. 
         [0022]    At the front of baler  10  generally below chamber  28  is disposed a pickup  36  that may be of conventional construction for the purpose of picking up the material from the ground as baler  10  is advanced and delivering such materials into the lower front portion of baling chamber  28 . A variety of such pickups  36  and associated mechanisms, such as a center-gathering auger  38 , may be utilized without departing from the principles of the present invention. 
         [0023]    The axes of rotation of the two wheels  14 ,  16  are disposed in mutual axial alignment. As illustrated best in  FIGS. 3 and 4 , such axes are denoted by the numeral  40  and are disposed rearwardly of the fore-and-aft center  42  of baling chamber  28  when chamber  28  is full-size. Thus, the center of gravity of bale  30  when full-size, which corresponds to baling chamber center  42 , is likewise disposed forwardly of the axes  40  of wheels  14 ,  16 . This provides significant load distribution benefits but also presents a problem during unloading of the finished bale if the wheel axes  40  are defined by a cross axle having its longitudinal axis coinciding with the axes  40 . Such an arrangement would most likely cause a bale ejecting from chamber  28  when tailgate  32  is raised to be caught by the axle and chassis instead of falling completely to the ground. 
         [0024]    In accordance with the present invention, wheel axes  40  are defined by a pair of relatively short spindles  44  that project laterally outwardly from opposite sides of the baler. Each spindle  44  rotatably supports a hub  46  at its outer end that is bolted to the corresponding wheel  14 ,  16 . At their inner ends, each spindle  44  is fixed to a forwardly extending wheel arm  48  located outboard of respective side panels  20  and  22 . At their forward ends, wheel arms  48  are fixed to a pair of inwardly extending, square shafts  50  ( FIG. 6 ) that are rotatably received within the opposite ends of a tubular square axle  52 . 
         [0025]    Axle  52 , shafts  50 , wheel arms  48 , spindles  44  and hubs  46  all comprise components of a suspension axle assembly broadly denoted by the numeral  54 . Suspension axle assembly  54  is rigidly affixed to chassis  12  via a pair of mounting brackets  56  fixed to axle  52  adjacent opposite ends thereof. Each bracket  56  is bolted to the underside of chassis  12  using a pair of bolt assemblies  58 . 
         [0026]    The tubular nature of axle  52  results in the sidewalls of axle  52  defining an internal chamber  60 . Although chamber  60  is the same square shape as shafts  50 , it is approximately one-third larger than shafts  50  such that there is space surrounding shafts  50  within chamber  60 . This space is, for the most part, occupied by resilient cushion structure in the nature of four resilient pads  62  for each shaft  50 . Pads  62  comprise a further part of suspension axle assembly  54  and are arranged between external surfaces of each shaft  50  and proximal internal surfaces of the sidewalls that define chamber  60 . 
         [0027]      FIG. 7  illustrates one of the wheel arms  48  in an essentially no-load situation in which pads  62  are yieldably retaining shaft  50  against rotation relative to axle  52  but are not exerting significant resistive rotational force. In this no-load position, shaft  50  is rotatively indexed approximately 45° degrees from axle  52  such that the broad, flat surfaces of shaft  50  are facing respective internal comers of chamber  60 . Pads  62  are generally triangular in transverse cross-sectional configuration and have their apexes matingly received within the comers of chamber  60  with their broad bases engaging the flat surfaces of shaft  50 . In this no-load position of  FIG. 7 , wheels  14 ,  16  are in their lowermost position relative to axle  52 . 
         [0028]      FIG. 8  shows wheel arm  48  raised to a nominal, load-bearing position rotated counterclockwise from its lowermost  FIG. 7  position. Shaft  50  is correspondingly rotated counterclockwise within axle  52 , causing pads  62  to be compressed and flattened out as the flat external surfaces of shaft  50  move toward a parallel relationship with the flat internal surfaces of chamber  60 . Pads  62  yieldably resist rotation of shaft  50  in the counterclockwise direction corresponding to upward swinging of wheel arm  48 . 
         [0029]      FIG. 9  illustrates wheel arm  48  in its uppermost position corresponding to the highest position of wheels  14 ,  16  relative to axle  52 . In this position pads  62  are in their most compressed state and are exerting their maximum resistive force against counterclockwise rotation of wheel arm  48 . This position corresponds to a shock load position such as occurring when the wheel associated with arm  48  encounters a sudden impact load from the ground or roadway. In stable, flat and relatively smooth conditions when the baler is fully loaded with a full size bale, it is contemplated that wheel arms  48  will be in their essentially horizontal, nominal load positions of  FIG. 8 . 
         [0030]    It is to be noted that the two shafts  50  are not connected to one another at their inboard ends. Thus, each shaft  50  is free to rotate independently of the other within axle  52 . This provides each of the wheels  14 ,  16  with an independent suspension, allowing each to react as needed to abrupt terrain changes that might be encountered by that particular wheel. 
         [0031]    It is also to be noted that axle  52  is offset a substantial distance forwardly of the wheel spindles  44 . Thus, the region under and across bale chamber  28  between wheel spindles  44  is open and unobstructed. As bale  30  exits the baler as shown in  FIG. 5 , the absence of axle  52  between spindles  44  enables bale  30  to drop to the ground rather than being caught by axle  52 . While the exiting bale  30  typically engages axle  52  as the bale leaves chamber  28 , its rolling motion and downward momentum is enough to carry it on past axle  52  and onto the ground without stopping. Thereupon, kicker  34  may be actuated to roll bale  30  rearwardly a sufficient distance that tailgate  32  can be closed. 
         [0032]    It has been found that one suitable axle assembly for serving as axle assembly  54  of the present invention is available from Off Highway Systems, Henschen Products Group of Jackson Center, Ohio. This axle assembly is marketed by such company under the trademark and name “Dura-Flex” Rubber Torsion Axle. 
         [0033]    It should be apparent from the foregoing that shafts  50  and pads  62  collectively comprise suspension apparatus  64  that is operably interposed between axle  52  and pivotal arms  48 . A baler  10  constructed in accordance with the present invention is thus provided with a suspension system that gently cushions the ride of the baler and eliminates damaging shock loads that would otherwise jar both the machine and the operator. As the baler  10  is towed across the field or along the road, wheels  14 ,  16  simply yield upwardly as needed under the cushioning resistance of the pads  62  to absorb bumps and other abrupt terrain changes to smooth out the ride. Having each wheel  14 ,  16  independently suspended permits each wheel to accommodate its own individual shock loads without affecting the other wheel, thus providing a steadier, more level ride for the baler than might otherwise be the case. Furthermore, all of these benefits are achieved without impeding the discharge of a finished bale from the bale chamber when the baling cycle has been completed. 
       Prior Art Baler of FIGS. 10 and 11 
       [0034]    The prior art baler  70  in  FIGS. 10 and 11  has no suspension system. Its ground wheels  72 ,  74  have their axes of rotation  76  disposed in axial alignment with one another below and behind the fore-and-aft center  78  of baling chamber  80 . A transversely circular, fixed axle  82  spans baling chamber  80  below the same and is rigidly affixed at its opposite ends to a pair of fore-and-aft beams  86 . Beams  84 ,  86  are secured to chassis  88  of baler  70  by bolts  90 . 
         [0035]    Wheel axes  76  are defined by a pair of spindles  92  disposed at the rear ends of beams  86  and projecting laterally outwardly therefrom. Axle  82  is thus offset forwardly from spindles  92  so as to clear out the area between spindles  92  and prevent interference with a discharging bale from chamber  80 . 
         [0036]    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.