Patent Publication Number: US-2021168990-A1

Title: Articulated implement towing apparatus

Description:
This application claims the benefit under 35 U.S.C. 119 (e) of U.S. provisional application Ser. No. 62/945,615, filed Dec. 9, 2020. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a towing apparatus for connection between a towing vehicle and an implement to be towed which is articulated to allow the implement to be towed in a laterally offset relationship to the towing vehicle, and more particularly the present invention relates to an articulated towing apparatus which is able to transfer drive from the power take-off shaft of the towing vehicle to the implement. 
     BACKGROUND 
     When towing an implement behind a tractor, such as a mower deck driven by a power take-off of the tractor, it is desirable in some instances to tow the implement along a path which is laterally offset to one side relative to the towing vehicle, for example when it is desirable to tow a mower deck along an inclined ditch while the tractor remains along the adjacent road to prevent tipping of the tractor into the ditch. 
     In some instances, the mower itself is capable of being towed in an offset arrangement by being provided with a dedicated towing arm as described in U.S. Pat. Nos. 4,525,987 and 4,714,123 both by Kuhn, S. A. In each instance the offset arm is an integral part of the mower deck such that the mower deck cannot be used for direct connection to the towing vehicle as may be desired in some instances. Furthermore, the offset towing arm cannot be used with other implements. High clearance is provided by the dedicated towing arm, however, in each instance the frame includes a longitudinal frame member extending horizontally from the towing vehicle to the mower deck such that the rear end of the frame member obstructs the operator&#39;s view of the implement. 
     In other instances, an independent towing arm is provided for connection between the tractor and a towed implement. One such example is described in U.S. Pat. No. 2,421,044 by Vutz; however, this device is provided with low clearance which is problem when passing over any large ground contours and slopes. Other examples of towing arms which can be used between a tractor and an implement include U.S. Pat. No. 7,334,645 by Degelman Industries Ltd and U.S. Pat. No. 9,504,202 by Highline Manufacturing Ltd; however, in each instance high clearance is only provided by a longitudinal frame member extending horizontally from the towing vehicle to the mower deck such that the rear end of the frame member again obstructs the operator&#39;s view of the implement. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention there is provided an articulated towing apparatus for pulling a rotary driven implement in a forward working direction across a ground surface behind a towing vehicle having a power take-off member, the apparatus comprising:
         a longitudinal frame which is elongate in a longitudinal direction between a leading end and a trailing end;   a wheeled frame supported on wheels for rolling movement along the ground surface, the wheeled frame being pivotally coupled to the longitudinal frame in proximity to the trailing end such that the wheeled frame is pivotal relative to the longitudinal frame about a first upright axis, and the wheeled frame being adapted to releasably connect the rotary driven implement thereto in trailing relationship with the wheeled frame;   a coupling frame adapted to be connected to the towing vehicle, the coupling frame being pivotally coupled to the longitudinal frame in proximity to the leading end such that the coupling frame is pivotal relative to the longitudinal frame about a second upright axis;   a driveline including a longitudinal drive shaft supported on the longitudinal frame, the longitudinal drive shaft being operatively connected to an input member at a leading end of the driveline and being operatively connected to an output member at a trailing end of the driveline, the input member being adapted to connect to the power take-off member of the towing vehicle and the output member being adapted to connect to the rotary driven implement;   the driveline further comprising:
           a lower gearbox supported on the coupling frame, the lower gearbox having an input connected to the input member and an output;   an upright shaft connected to the output of the lower gearbox;   an upper gearbox supported on the longitudinal frame above the lower gearbox in proximity to the leading end of the longitudinal frame, the upper gearbox having an input connected to the upright shaft and an output operatively connected to the longitudinal drive shaft; and   a universal connection at the trailing end of the longitudinal frame, the universal connection operatively connecting the longitudinal drive shaft to the output member of the driveline;   the longitudinal drive shaft extending at a downward slope from the leading end to the trailing end of the driveline.   
               

     Preferably the longitudinal frame is hollow and receives the longitudinal drive shaft therein. The longitudinal frame may further include a tubular frame member spanning a majority of a length of the longitudinal frame, the tubular frame member extending at a downward slope from the leading end to the trailing end of the longitudinal frame and receiving the longitudinal drive shaft therein. 
     Use of a longitudinal drive shaft extending at a downward slope from an arrangement of gearboxes at the leading end of the frame enables high clearance at the leading end of the frame and a low elevation at the trailing end of the frame to maintain high clearance for the implement while also not obstructing the operator&#39;s view of the implement and the field conditions rearward of the implement. 
     Preferably the output member is rotatably supported on the wheeled frame, whereby the output member is pivotal about the first upright axis with the wheeled frame relative to the longitudinal frame. The output member may be rotatably supported on the wheeled frame at a location spaced rearwardly from the first upright axis. 
     The universal connection of the driveline may comprise an intermediate shaft operatively connected to the longitudinal drive shaft by a first universal joint ahead of the first upright axis and operatively connected to the output member by a second universal joint behind the first upright axis. 
     The wheeled frame preferably comprises a crossbar member pivotally coupled to the trailing end of the longitudinal frame for relative pivotal movement about the first upright axis, in which the crossbar member extends in a lateral direction between opposing ends and in which each opposing end supports a respective one of the wheels thereon. In this instance, the wheeled frame is preferably adapted to releasably connect the rotary driven implement thereto at a location spaced rearwardly of the first upright axis. 
     The driveline may further comprise a universal connection operatively connecting the longitudinal drive shaft to the output of the upper gearbox. In this instance, the coupling frame may comprises: (i) an intermediate portion supporting the lower gearbox thereon, the intermediate portion being connected to the longitudinal frame for relative pivotal movement about the second upright axis; and (ii) a coupling portion adapted to be connected to the towing vehicle, in which the coupling portion and the intermediate portion are pivotally coupled to one another for relative pivotal movement about a longitudinal roll axis oriented in the forward working direction. The coupling portion may be further adapted to be coupled to the towing vehicle so as to be pivotal relative to the towing vehicle about a lateral axis oriented transversely to the forward working direction. In this instance, the coupling portion may comprise a pair of coupling pins which are spaced apart along the lateral axis at diametrically opposing sides of the driveline. 
     The driveline is preferably supported in alignment with the longitudinal roll axis at the leading end of the longitudinal frame. 
     The apparatus may further comprise a latching mechanism operatively connected between the longitudinal frame and the wheeled frame, in which the latching mechanism includes a latch member which is movable between a latched position in which the latch member restricts relative pivotal movement between the longitudinal frame and the wheeled frame about the first upright axis and a released position in which the latch member does not restrict relative pivotal movement between the longitudinal frame and the wheeled frame about the first upright axis. 
     The latching mechanism is preferably operable to fix the wheeled frame relative to the longitudinal frame in a straight position in which the wheels are oriented for rolling in the longitudinal direction of the longitudinal frame. 
     The apparatus may further comprise a steering actuator operatively connected between the longitudinal frame and the wheeled frame such that the wheeled frame is pivoted relative to the longitudinal frame about the first upright axis under control of the steering actuator. Preferably the wheeled frame supports the wheels thereon for rolling movement about a wheel axis and the steering actuator comprises a linear actuator which is oriented substantially parallel to the wheel axis. 
     According to a second aspect of the present invention there is provided an articulated towing apparatus for pulling a rotary driven implement in a forward working direction across a ground surface behind a towing vehicle having a power take-off member, the apparatus comprising:
         a longitudinal frame which is elongate in a longitudinal direction between a leading end and a trailing end;   a wheeled frame supported on wheels for rolling movement along the ground surface, the wheeled frame being pivotally coupled to the longitudinal frame in proximity to the trailing end such that the wheeled frame is pivotal relative to the longitudinal frame about a first upright axis, and the wheeled frame being adapted to releasably connect the rotary driven implement thereto in trailing relationship with the wheeled frame;   a coupling frame adapted to be connected to the towing vehicle, the coupling frame being pivotally coupled to the longitudinal frame in proximity to the leading end such that the coupling frame is pivotal relative to the longitudinal frame about a second upright axis;   a driveline including a longitudinal drive shaft supported on the longitudinal frame, the longitudinal drive shaft being operatively connected to an input member at a leading end of the driveline and being operatively connected to an output member at a trailing end of the driveline, the input member being adapted to connect to the power take-off member of the towing vehicle and the output member being adapted to connect to the rotary driven implement;   wherein the output member is rotatably supported on the wheeled frame, whereby the output member is pivotal about the first upright axis with the wheeled frame relative to the longitudinal frame.       

     Preferably the output member is rotatably supported on the wheeled frame at a location spaced rearwardly from the first upright axis. 
     By providing the output member of the driveline on the wheeled frame, the output of the driveline remains optimally aligned with the driven input on the implement throughout the range of offset movement of the apparatus relative to the towing vehicle and the implement. 
     According to a further aspect of the present invention there is provided an articulated towing apparatus for pulling a rotary driven implement in a forward working direction across a ground surface behind a towing vehicle having a power take-off member, the apparatus comprising:
         a longitudinal frame which is elongate in a longitudinal direction between   a leading end and a trailing end;   a wheeled frame supported on wheels for rolling movement along the ground surface, the wheeled frame being pivotally coupled to the longitudinal frame in proximity to the trailing end such that the wheeled frame is pivotal relative to the longitudinal frame about a first upright axis, and the wheeled frame being adapted to releasably connect the rotary driven implement thereto in trailing relationship with the wheeled frame;   a coupling frame adapted to be connected to the towing vehicle, the coupling frame being pivotally coupled to the longitudinal frame in proximity to the leading end such that the coupling frame is pivotal relative to the longitudinal frame about a second upright axis;   a driveline including a longitudinal drive shaft supported on the longitudinal frame, the longitudinal drive shaft being operatively connected to an input member at a leading end of the driveline and being operatively connected to an output member at a trailing end of the driveline, the input member being adapted to connect to the power take-off member of the towing vehicle and the output member being adapted to connect to the rotary driven implement;   wherein the coupling frame comprises:
           (i) an intermediate portion connected to the longitudinal frame for relative pivotal movement about the second upright axis; and   (ii) a coupling portion adapted to be connected to the towing vehicle, the coupling portion and the intermediate portion being pivotally coupled to one another for relative pivotal movement about a longitudinal roll axis oriented in the forward working direction.   
               

     Preferably the coupling portion is adapted to be coupled to the towing vehicle so as to be pivotal relative to the towing vehicle about a lateral axis oriented transversely to the forward working direction. 
     The configuration of the coupling frame described herein defines two axes of movement of the apparatus relative to the vehicle with a third axis of movement being optionally provided by the connection of the coupling frame to the towing vehicle. This allows the apparatus to be coupled to the towing vehicle for relative movement about pitch, roll and yaw axes to ensure that the implement closely follows contours and slopes of the ground regardless of the relative position of the towing vehicle. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       One embodiment of the invention will now be described in conjunction with the accompanying drawings in which: 
         FIG. 1  is a perspective view of the articulated towing apparatus; 
         FIG. 2  is a side elevational view of the articulated towing apparatus; 
         FIG. 3  is a top plan view of the articulated towing apparatus shown connected between a towing vehicle and an implement to be towed in a straight configuration; 
         FIG. 4  is a partly sectional view of a leading end of the apparatus along the line  4 - 4  in  FIG. 1 ; 
         FIG. 5  is a partly sectional view of a trailing end of the apparatus along the line  4 - 4  in  FIG. 1 ; and 
         FIG. 6  is a top plan view of the articulated towing apparatus shown connected between the towing vehicle and the implement to be towed in an offset configuration. 
     
    
    
     In the drawings like characters of reference indicate corresponding parts in the different figures. 
     DETAILED DESCRIPTION 
     Referring to the accompanying figures there is illustrated an articulated implement towing apparatus generally indicated by reference numeral  10 . The apparatus  10  is particularly suited for use with a rotary driven implement  12  such as a mower deck, to be towed by a towing vehicle  14  in a forward working direction  15  of the vehicle and the implement. 
     The towing vehicle  14  may be an agricultural tractor having a frame supported on wheels for rolling movement along the ground, powered by an engine on the frame which drives the wheels. The tractor includes a hitch, for example a three-point hitch having a pair of laterally spaced apart coupling arms  16  arranged to mount various implements thereon to be towed across a ground surface together with the towing vehicle in the forward working direction. The towing vehicle further includes a power take-off shaft  18  which is a rotary driven shaft that is powered by the engine of the tractor directly or indirectly, for example through a hydraulic system of the vehicle. 
     The implement  12  typically comprises a frame that is also supported on wheels for rolling movement across the ground surface in the forward working direction. The implement  12  includes a hitch connector  20  at a leading end thereof which is typically adapted for connection to the hitch of the towing vehicle for direct towing in trailing relationship with the towing vehicle. The implement also includes a driven element, for example the rotating mower blades on a mower deck. A drive coupling  22  is supported on the mower deck in operative connection with the driven element, in which the drive coupling  22  is adapted for connection to the power take-off shaft  18  or other suitable drive output of a typical towing vehicle. 
     The apparatus  10  according to the present invention is intended to be coupled between the towing vehicle  14  and the towed implement  12  so as to enable the implement to be controllably positioned relative to the towing vehicle in a lateral direction perpendicular to the forward working direction. The articulation of the apparatus  10  allows the implement  12  to be displaced from a straight configuration shown in  FIG. 3  in which the apparatus  10  is parallel to the forward working direction so that the implement follows the path of the towing vehicle to an offset configuration shown in  FIG. 6  in which the apparatus is oriented transversely to the forward working direction so that the implement follows a path that is parallel to and laterally offset to one side of the path of the towing vehicle. 
     The apparatus  10  generally comprises (i) a coupling frame  24  at a leading end of the apparatus for coupling the apparatus to the towing vehicle, (ii) a wheeled frame  26  at the trailing end of the apparatus which is arranged for rolling movement along the ground, and (iii) a longitudinal frame  28  extending generally in the forward working direction between a trailing end which is pivotally coupled to the wheeled frame  26  for relative pivotal movement about a first upright axis  30  and a leading end which is pivotally coupled to the coupling frame  24  for relative pivotal movement about a second upright axis  32 . 
     In some embodiments, where no power transfer is required between the towing vehicle and the implement, the apparatus  10  may consist only of the coupling frame, the wheeled frame, and the longitudinal frame together with controls for steering the wheeled frame relative to the longitudinal frame. 
     In the illustrated embodiment, the apparatus  10  further includes a driveline for transferring power from an input member  34  of the driveline which is adapted for connection to the power takeoff shaft of the towing vehicle at the leading end of the apparatus to an output member  36  of the driveline which is adapted for connection to the drive input of the implement at the trailing end of the apparatus. 
     In the illustrated embodiment, the coupling frame  24  includes an intermediate portion  38  which is pivotally coupled to the leading end of the longitudinal frame to define the second upright axis  32 , and a coupling portion  40  which is adapted to be connected to the hitch connector of the towing vehicle. The coupling portion and the intermediate portion  38  of the coupling frame are coupled to one another for relative pivotal movement about a longitudinal rolling axis  42  that is oriented in the forward working direction of the vehicle. 
     The intermediate portion  38  of the coupling frame comprises a hollow housing  44  having an upper chamber  46  which is generally tubular in shape and which is open at the top end thereof, and a front chamber  48  which is also tubular in shape but is open to the front of the apparatus. The upper chamber and front chamber are openly connected to form a generally L-shaped interior space within the intermediate portion of the coupling frame. An outlet collar  50  is fixed to the top end of the housing with an opening therethrough aligned with the open top end of the upper chamber. A portion of the longitudinal frame is received about the outlet collar  52  so as to maintain relative rotation therebetween about the second upright access  32 . A retainer flange  52  is releasably fastened at the top end of the outlet collar  50  to retain the portion of the longitudinal frame rotatably supported about the outlet collar in an assembled configuration of the apparatus as described in further detail below. 
     Similarly, an inlet collar  54  is fixed at the front end of the hollow housing so that the opening through the collar is in open communication with the front chamber  48  of the intermediate portion of the coupling frame. 
     The coupling portion of the coupling frame in this instance includes a sleeve  56  having an inner diameter which closely fits about the outer diameter of the inlet collar  54  such that the sleeve  56  is rotatably supported about the inlet collar  54 . The mounting of the sleeve  56  onto the collar  54  defines the longitudinal rolling axis  42  of the coupling portion  40  relative to the intermediate portion  38  of the coupling frame. A retainer flange  58  is releasably fastened at the front end of the inlet collar  54  to retain the sleeve  56  in axial position along the collar  54  whereby the sleeve  56  is retained between the retainer flange  58  at the leading end and is retained by a front wall of the hollow housing  54  at the trailing end thereof. A layer of bushing material having a low efficient of friction or a layer of grease may be provided at the interface between the sleeve  56  and the collar  54  so that the sleeve readily rotates about the collar. 
     The coupling portion  40  of the coupling frame further comprises two side frames  60  protruding outwardly from diametrically opposing sides of the sleeve  56  in fixed relation therewith such that the side frames  60  rotate with the sleeve relative to the collar  54 . The side frames are defined by a pair of plates  62  which are fixed to the sleeve  56  and which are coupled by transverse end plates such that the two plates  62  form a rigid frame. The plates  62  are oriented perpendicularly to the axis of the sleeve  56  at axially opposing leading and trailing ends of the sleeve for abutting the inner surface of the retainer flange  58  at the leading end of the sleeve and for abutting the forward face of the front wall of the housing  54  at the trailing end of the sleeve. 
     The side frames  60  which extend radially outward from opposing sides of the sleeve serve to support a pair of connecting arms  64  which protrude forwardly from the side frames respectively in parallel relation to one another and to the longitudinal rolling axis. The connecting arms are mounted on the side frames respectively such that the connecting arms are diametrically opposite one another relative to the longitudinal rolling axis while also being at diametrically opposing sides of the driveline which is received concentrically through the inlet collar  54  at the leading end of the apparatus. A pair of transverse pins  66  are fixed at the leading end of the connecting arms  64  respectively to extend laterally outward therefrom along a common lateral pitch axis  68  relative to one another. The transverse pins  66  are laterally spaced apart from one another and suitably oriented for being received within mating mounting locations on the two lower hitch arms  16  of the towing vehicle. The transverse pins are arranged to be pivotally coupled to the hitch arms  16  of the towing vehicle so that the pivoting movement of the coupling frame relative to the hitch connector of the towing vehicle defines the lateral pitch axis  68 . 
     The wheeled frame  26  of the apparatus includes a crossbar member  70  which extends in a lateral direction between opposing ends of the crossbar member. Two wheels  72  are mounted on the opposing ends of the crossbar member  70  respectively such that each wheel is rotatable relative to the wheeled frame about a common lateral axis of the wheels, wherein the lateral axis is oriented parallel to the crossbar member  70 . The wheels are fixed in orientation relative to the crossbar with the lateral axis of rotation of the wheels being generally centred in the longitudinal direction of the apparatus relative to the crossbar. 
     The wheeled frame further includes a trailing member  74  which is fixed onto the crossbar member  70  at a laterally centred location to extend rearwardly in a trailing relationship with the crossbar member. The trailing member is fixed to the crossbar to extend rearward to a rear end supporting a hitch tongue  76  thereon in the form of a generally horizontal plate with a mounting aperture extending therethrough. The mounting aperture serves for attachment of a hitch, for example a hitch ball or hitching ring or other suitable hitch connector that is capable of coupling the implement thereon while allowing some relative movement of the implement relative to the wheeled frame. 
     The wheeled frame  26  further includes a pivot coupling at a laterally centred location within the crossbar member which defines the first upright axis of pivotal movement of the wheeled frame relative to the longitudinal frame. The pivot coupling includes top and bottom pivot support plates  78  mounted at top and bottom sides of the crossbar member with respective openings therein which are aligned with one another along the upright axis. A pivot shaft  80  extends along the first upright axis fully through the pivot support plates  78  at the top and bottom sides of the crossbar member so that the pivot shaft is freely rotatable relative to the wheeled frame. Retainer flanges  82  are fixed to the pivot shaft  80  at opposing top and bottom end thereof for abutting corresponding upper and lower faces of the top and bottom pivot support plates  78  respectively to axially locate the pivot shaft  80  relative to the crossbar while the pivot shaft remains freely rotatable relative to the crossbar member. The longitudinal frame is coupled to the pivot shaft  80  as described in further detail below to enable the longitudinal frame to be pivotal relative to the wheeled frame  26  about the first upright axis  30 . 
     The wheeled frame  26  further includes a mounting plate  84  supported on the top side of the trailing member  74  at a location which is spaced rearwardly from the crossbar and from the first upright axis. The mounting plate  84  is generally parallel to the crossbar and perpendicular to the forward working direction. The mounting plate  84  includes a central opening supporting a bearing therein which in turn supports the output member  36  of the driveline rotatably therein. The output member is supported by the bearing in fixed orientation relative to the mounting plate such that an axis of the output member of the driveline remains oriented in the rolling direction of the wheels of the wheeled frame corresponding approximately to the forward working direction. 
     An additional cover plate  86  is mounted at the top end of the mounting plate  84  to protrude both forwardly and rearwardly from the mounting plate for shielding a portion of the driveline immediately ahead of and rearward of the mounting plate  84 . 
     A pair of poles  88  extend upward from the ends of the crossbar member  70  respectively for supporting respective navigation lights  90  thereon. 
     The longitudinal frame  28  comprises a tubular frame member  92  which extends in a respective longitudinal direction to span a majority of the length of the longitudinal frame, and a majority of the length of the overall apparatus. The tubular frame member  92  extends at a downward slope from a leading end to a trailing end thereof. A mounting arm  94  is fixed to the leading end of the tubular frame member  92  to extend forward at a downward inclination to a front end of the mounting arm which is fixed externally onto a sleeve  96 . The sleeve  96  has an inner diameter which closely fits about the outer diameter of the outlet collar  50  of the coupling frame at the leading end of the apparatus. The retainer flange  52  is fixed to the top end of the outlet collar in a manner which restricts the axial position of the sleeve  96  along the outlet collar while enabling the sleeve to remain freely rotatable about the outlet collar  50 . A layer of bushing material having a low coefficient of friction may be provided between the inner surface of the sleeve and the outer surface of the outlet collar, or alternatively a layer of grease may be provided therebetween, to ensure that the sleeve  96  is freely rotatable about the outlet collar. The sleeve  96  may be further provided with end flanges  98  which extend radially outward from top and bottom ends of the sleeve  96  respectively. The outer end faces of the end flanges  98  are abutted in rotatable engagement with corresponding surfaces at the inner side of the retainer flange  52  thereabove and on the end face of the top wall of the housing  44  of the intermediate portion of the coupling frame therebelow. The rotatable connection thus supports axial loads and radial loads between the intermediate frame and the coupling frame, similarly to the other pivot connections of (i) the longitudinal frame to the wheeled frame, and (ii) the intermediate portion of the coupling frame to the coupling portion of the coupling frame. 
     An input housing  100  is provided at the leading end of the longitudinal frame. The input housing as a hollow interior which is open at the rear side to the hollow interior of the tubular frame member  92  upon which it is fixedly supported. The hollow interior of the input housing is also open at the bottom end thereof to the hollow interior of the outlet collar while the input housing  100  of the longitudinal frame remains pivotal relative to the outlet collar about the second upright axis  32 . 
     An upper gearbox  102  is located within the input housing  100  of the longitudinal frame. The gearbox has a housing which is fixed relative to the input housing. The upper gearbox comprises a right-angle gearbox having an input shaft  104  and an output shaft  106  which are offset 90 degrees from one another and which are connected internally to one another using beveled gears in meshing relationship with one another in the usual manner of a right-angle gearbox. The input shaft  104  is coupled to an upright shaft  108  which is vertically oriented and is substantially concentric with the second upright axis  32  as well as being concentric with the sleeve  96  and the outlet collar  50 . 
     The bottom end of the upright shaft  108  is coupled to the output shaft  110  of a lower gearbox  112 . Similarly to the upper gearbox, the lower gearbox has a housing which is fixed relative to the corresponding housing within which it is received, that is the housing  44  of the intermediate portion of the coupling frame in this instance. In addition to the output shaft  110 , the lower gearbox  112  includes an input shaft  114  which is offset from the output shaft by 90 degrees while being connected internally to one another using beveled gears in meshing relationship with one another in the usual manner of a right-angle gearbox. The input shaft  114  of the lower gearbox is concentrically aligned with the longitudinal rolling axis  42  and with the sleeve  56  rotatably supported about the inlet collar  54 . 
     The longitudinal frame member supports a longitudinal driveshaft  116  therein which extends the full length of the tubular frame member within which it is received. The longitudinal driveshaft  116  is generally concentric with the tubular frame member  92  such that the longitudinal driveshaft  116  also extends at a downward slope from the leading end to the trailing end thereof. The driveshaft  116  is supported rotatably relative to the tubular frame member by a plurality of bearings  118  mounted about the driveshaft and supported relative to the surrounding tubular frame member by respective mounting plates at longitudinally spaced positions along the length of the tubular frame member  92 . 
     The driveshaft  116  is connected to the output shaft  106  of the upper gearbox by a universal connection. The universal connection includes a first universal joint  120  coupled to the output shaft  106  and a second universal joint  122  connected to the leading end of the longitudinal driveshaft, with an intermediate shaft  124  being connected between the first and second universal joints. The intermediate shaft  124  is slightly angularly offset from the output shaft of the upper gearbox by the first universal joint  120  while the driveshaft  116  is similarly angularly offset from the intermediate shaft by the second universal joint  122 . 
     At the trailing end of the longitudinal frame, a further mounting arm  126  is mounted in fixed relation to the tubular frame member  92  to extend rearwardly from the bottom of the tubular frame member at a downward slope to a rear end of the mounting arm. The rear end of the mounting arm  126  is forked to define an upper portion  128  extending above the crossbar member of the wheeled frame and a lower portion  130  extending below the crossbar member of the wheeled frame. The upper portion  128  and the lower portion  130  are fixedly coupled to the top end and bottom end respectively of the pivot shaft  80  of the pivot coupling on the wheeled frame  26 . 
     A steering actuator  132  is provided for controlling pivotal movement of the wheeled frame relative to the longitudinal frame about the first upright axis  30 . The steering actuator is a linear hydraulic actuator which is supported at a location spaced rearward of the crossbar so as to extend generally parallel to the crossbar in the lateral direction of the crossbar. A first crank  134  is fixed onto the crossbar towards one of the ends of the crossbar for mounting a first end of the steering actuator pivotally thereon. A second crank member  136  is fixed relative to the longitudinal frame to extend rearwardly from the upper portion  128  of the mounting arm at the trailing end of the longitudinal frame. The second crank member  136  pivotally couples a second end of the steering actuator thereon. In this manner extending and retracting the overall length of the actuator causes the wheeled frame to be pivoted between the straight configuration shown in  FIG. 3  and the offset configuration shown in  FIG. 6 . 
     In the straight configuration, the wheeled frame and the implement connected thereto follow the path of the vehicle by orienting the longitudinal frame to extend perpendicularly to the crossbar of the wheeled frame and parallel to the forward working direction. The wheels are oriented for rolling in the forward working direction parallel to the longitudinal frame in this instance. 
     In the offset configuration, the wheeled frame and the implement connected thereto follow a path which is parallel and laterally offset to one side of the path of the vehicle by orienting the longitudinal frame to extend transversely to the forward working direction and non-perpendicularly to the crossbar. The wheels are oriented for rolling in the forward working direction transversely to the longitudinal frame in this instance. 
     The driveline further comprises a universal connection between a rear end of the longitudinal driveshaft  116  at the trailing end of the tubular frame member  92  and the output member  36  that is rotatably supported on the wheeled frame. The universal connection at the trailing end of the driveshaft includes a first universal joint  138  coupled to the rear end of the longitudinal driveshaft at a location spaced forwardly of the first upright axis  32  and a second universal joint  140  coupled to the leading end of the output member  36  at a location spaced rearwardly of the first upright axis  32 . An intermediate shaft  142  is coupled between the first and second universal joint  138  and  140 . 
     In order to couple the driveline of the apparatus to the power takeoff shaft  18  of the towing vehicle, the input member  34  is a shaft supported by respective bearings coaxially within the inlet collar  54  at the leading end of the apparatus. A leading universal connection  146  may be coupled at the leading end of the input shaft  34  which forms the connection to the shaft  18  of the towing vehicle. The universal connection  146  may comprise an intermediate shaft connected between first and second universal joints similarly to the universal connections described above. 
     In order to couple the driveline of the apparatus to the drive input of the implement, a similar output universal connection  148  may be connected between the output member  36  at the trailing end of the apparatus and the drive input of the implement. The output universal connection  148  may comprise an intermediate shaft connected between first and second universal joints similarly to the universal connections described above. 
     Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.