Abstract:
A continuous track assembly having forward and rearward track engaging wheels with a intermediate track engaging wheel position between them. A continuous track extends over the wheels. A foldable frame journals the wheels and is displaceable between a position where the track engaging wheels are in substantially the same plane and another position in which they are in a triangular configuration.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to continuous track assemblies, and, more specifically, to continuous track assemblies having variable geometry. 
         [0003]    2. Description of the Related Art 
         [0004]    A recent trend in the farm implement business has been the increasing use of continuous tracks in place of wheels for farm implements. The continuous track offers the advantage of a lower unit pressure owing to the significantly larger ground engaging area when compared to a simple wheel assembly. This is especially advantageous in multi-row planters where the added weight of the overall assembly makes it important to provide ground support that is does not allow the planter to sink into the soil. 
         [0005]    While the continuous track assemblies provide a lower ground engaging unit pressure, they tend to be bulkier which is a problem when employed on planting implements that are articulated between a planting and transport position. The continuous track assembly can interfere with the planter frame elements as they are folded into a transport position. In addition, the continuous track assemblies, because of having a greater ground engaging area, make it harder to turn and maneuver the planter when it is in the transport position. 
         [0006]    Accordingly, what is needed in the art is a continuous track assembly that offers low ground engaging unit area pressure yet offers easy maneuverability in a transport position. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention seeks to achieve a solution to the above problems by providing variable geometry continuous track assemblies. 
         [0008]    The present invention also solves the above problems in a simplified and cost effective way. 
         [0009]    In one form, the invention is a continuous track assembly including a forward track engaging wheel and a rearward track engaging wheel. An intermediate track engaging wheel is positioned between the wheels and a continuous track extends around the wheels. A foldable frame journals the wheels and is displaceable between a first position in which the wheels are in substantially the same plane and a second position in which the wheels form a triangular configuration. 
         [0010]    In another form, the invention is a farm implement having a frame and a plurality of ground support assemblies. The ground support assemblies each includes a continuous track assembly with forward and rearward track engaging wheels and an intermediate track engaging wheel positioned between the wheels. A continuous track extends around the wheels and a foldable frame journals the wheels and is displaceable between a first position in which the wheels are in substantially the same plane and a second position in which the wheels form a triangular configuration. 
         [0011]    One advantage of the present invention is a lower ground engaging unit pressure in one configuration and another configuration offering easier maneuverability. 
         [0012]    Another advantage is the provision of a large surface area in one configuration. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    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 an embodiment of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0014]      FIG. 1  is a schematic side view of a farm implement with a ground support assembly embodying the present invention shown in a first position; and, 
           [0015]      FIG. 2  is a schematic side view of the ground support assembly of  FIG. 1  shown in a second position. 
       
    
    
       [0016]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates one embodiment of the invention and such exemplification is not to be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    Referring to  FIGS. 1 and 2 , there is shown a farm implement  10  with which the present invention may be used. Farm implement  10  is shown in abbreviated schematic fashion, but is intended to encompass self-propelled farm implements such as tractors, combines and the like and towed farm implements such as tillage assemblies and planters, among other things. The implements may be self-propelled or may be towed as is the nature of their duty cycle. Farm implement  10  has a plurality of continuous track assemblies  12 , only one of which is shown. Typically if the implement is self-propelled it would have a plurality of track assemblies such as 4. 
         [0018]    Each track assembly  12  includes a forward track engaging wheel  14 , a rearward track engaging wheel  16  and an intermediate track engaging wheel  18 . Forward track engaging wheel  14  is supported and journaled for rotation by a frame  20  and rearward track engaging wheel  16  is supported and journaled for rotation by a frame  22 . Frame members  20  and  22  are pivotally interconnected as illustrated at the rotational axis of intermediate wheel  18  so that the journaling component for wheel  18  also functions as the pivot point for frame members  20  and  22  which can be folded. A frame member  24  journals wheel  18 , supports it and interconnects the track assembly  12  to the farm implement  10 . Depending upon the function the interconnection  24  may be fixed or may be pivotable to provide maneuvering of the farm implement  10 . 
         [0019]    A continuous track  26  is received over wheels  14 ,  16  and  18  and provides contact with the soil over which the farm implement  10  moves. The exact nature of continuous track  26  is not shown, but it may be employed as a continuous toothed rubber belt or as interconnected pivotal links. A discreet number of links may be pivotally interconnected to form a continuous belt. Other forms of continuous track  26  may be employed and continue to use the benefits of the present invention. 
         [0020]    Tension assemblies  28  and  30  connected to frames  20  and  22 , respectively expand or contract to permit an appropriate level of continuous track tension for different geometries of the continuous track assembly  12 . Bogie wheels  32  and  34  are supported by forward bogie frame support  36  and rearward bogie frame support  38  to be journaled and to come in contact with the continuous track  26  for support when the assembly is in the configuration shown in  FIG. 1 . 
         [0021]    An actuator  40  having an extensible actuator rod  42  is pivotally connected to frames  20  and  22  through link connectors  44 . Actuator  40  is shown in  FIG. 1  in its extended configuration wherein the axis of wheels  14 ,  18  and  16  are substantially in the same plane. 
         [0022]    As shown in  FIG. 2 , the actuator  40  may be actuated to retract and to move the frames  20  and  22  into a triangular configuration during which the bogie wheels are displaced out of contact with the continuous track  20 . By displacing the track assemblies  12  between the configurations of  FIGS. 1 and 2 , the variable geometry provides optimum contact surface with the ground and at the same time provides increased maneuverability and flexibility. When the configuration is in that shown in  FIG. 1 , the farm implement is generally in a field position in which ground is tilled or seeds planted. In that position a maximum surface area with the ground is indicated by A is employed to result in unit pressure areas with respect to the ground that are within manageable limits. At this point, the ground clearance Al is at a minimum. When the implement  10  is placed in a transport position, the continuous track assemblies  12  are placed in the triangular configuration of  FIG. 2  so that the ground surface area shrinks from A to B while at the same time the ground clearance B′ increases. By reducing the unit area the maneuverability of the farm implement is enhanced because there is less resistance to turning movements by virtue of the lower surface area. In addition, the ground clearance B′ increases to increase the flexibility of movement over obstacles. Furthermore, when the continuous track assemblies  12  are utilized in a folding configuration planter, the triangular configuration of  FIG. 2  experiences less interference with the articulated members of the planter assembly. 
         [0023]    What has been described above is a towed farm implement. The implement  10  may be made in a self-propelled form by the use of a power unit  46  interconnected to one of the wheels  14 ,  16  and  18  to provide a driven track. As herein shown the intermediate wheel  18  is the driven wheel via a power train  48 . However, any of the other wheels may be driven as appropriate. It is to be noted that one or more of the continuous track assemblies  12  in the farm implement  10  may be driven to as needed for the particular function. 
         [0024]    When the continuous track assemblies  12  are in their in the position shown in  FIG. 1 , the bogie wheels  32  and  34  provide additional support between the various track engaging wheels. However, when the continuous track assembly  12  is pivoted to the position of  FIG. 2 , they are taken out of contact with the continuous track  26 . The tensioners  28  and  30  properly accommodate variations in length caused by the variable wrapping of continuous track  26  around the track engaging drive wheels. 
         [0025]    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.