referring to fig1 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 . 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 . 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 . 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 fig1 . 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 fig1 in its extended configuration wherein the axis of wheels 14 , 18 and 16 are substantially in the same plane . as shown in fig2 , 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 fig1 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 fig1 , 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 a1 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 fig2 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 fig2 experiences less interference with the articulated members of the planter assembly . 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 . when the continuous track assemblies 12 are in their in the position shown in fig1 , 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 fig2 , 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 . 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 .