Abstract:
An apparatus for facilitating steering, height adjustment and transport of a farm implement towed by a vehicle. The implement includes a main frame and a hitch that extends from the frame for linking to the vehicle. The apparatus comprises a wheel support member supported below the frame, at least a first ground engaging wheel supported by the wheel support member for rotation about a first wheel axis and to engage a ground surface below the frame thereby supporting the frame above the ground, a first hydraulic lift cylinder linked between the frame and the wheel support member and controllable to adjust the height of the frame above the ground, and a hydraulic steering cylinder mounted to the wheel support member and controllable to steer the first wheel independent of the state of the first lift cylinder.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to steering and lift mechanisms for agricultural implements and more specifically to an assembly that can be used to adjust the height of an implement main frame and to steer implement wheels. 
     Large agricultural planters typically include a central frame assembly that is supported by a plurality of ground engaging wheels, one or more long tool supporting booms or wing frame assemblies mounted to the central frame assembly and extending laterally there from to, as the label implies, support planter row units, and a hitch that extends in a forward direction from the frame to link the planter to a tractor or the like for transport. A typical row unit includes a disc or other ground engaging component for opening a seed trench of a certain depth in the ground as the planter is pulled through a field, a seed dispensing subassembly for dispersing seeds in a controlled fashion into the trench and, in many cases, other components for adjusting trench depth, seed dispersal rate, etc. Here, in some cases, the total length of the main frame and wing assemblies can be ninety feet or more so that wide swaths of a field can be planted during each pass there through. 
     While wide planters reduce the amount of time required to plant a field, planters with large widths make it difficult if not impossible to transport the planters to and from fields to be planted. For this reason wide planters have been designed that are typically reconfigurable to facilitate transport. For instance, in many cases wide planters have been designed with extendable hitches and with the long wing frame assemblies mounted to the central frame assembly to fold forward over a portion of the extended hitch prior to transport. In these cases the ground engaging wheels on the central frame assembly continue to support the central frame and folded wing frames for transport. 
     While row unit trenching discs and other row unit components have to contact or be very near ground surface level during a seeding activity, during transport row units have to be raised so that they clear ground surface level. To this end many planters have been designed that include systems for adjusting the height of wing frame assemblies above ground level so that row units can be positioned at various planting heights or a relatively high transport height. 
     In the case of folding wing planters where a hitch extends forward and wing assemblies fold forward over the hitch for transport, while planter width may be suitable for transport, the planter length is increased appreciably which can exacerbate the process of maneuvering the planter through turns. In this regard, when a planter hitch is extended and wing assemblies are folded into the transport position, the ground engaging wheels on the central frame assembly are far away from the end of the hitch linked to a tractor which means that the tractor/planter assembly has an extremely large turning radius in this configuration. A large turning radius can be particularly problematic when turning off a narrow road and through a narrow pass into a field or when maneuvering through other tight spots. 
     BRIEF SUMMARY OF THE INVENTION 
     It has been recognized that a combined steering/height adjustment assembly can be used to mount ground engaging wheels to a farm implement main/central frame assembly which can be used to both alter the height of the frame assembly and other components attached thereto above a ground level and to control steering of the ground engaging wheels to facilitate implement transport as well as steering when maneuvering through difficult turning activities. To this end, the present invention generally includes hydraulic cylinders for controlling wheel steering as well as frame height above ground. More specifically, the steering cylinder is mounted to a wheel support member and height adjust cylinders are linked between the frame assembly and the wheel support member. In this configuration, the steering cylinder only has to have enough force to change the direction of the wheels instead of having to alter the orientation of the entire wheel support member and height adjust cylinder assembly and therefore a relatively small steering cylinder is required. 
     At least some embodiments include a support assembly for facilitating steering, height adjustment and transport of a farm implement towed by a vehicle. The implement includes a main frame and a hitch that extends from the frame for linking to the vehicle. The assembly comprises a wheel support member supported below the frame, at least a first ground engaging wheel supported by the wheel support member for rotation about a first wheel axis and to engage a ground surface below the frame thereby supporting the frame above the ground, a first hydraulic lift cylinder linked between the frame and the wheel support member and controllable to adjust the height of the frame above the ground, and a hydraulic steering cylinder mounted to the wheel support member and controllable to steer the first wheel independent of the state of the first lift cylinder. 
     In some embodiments, the assembly includes at least a second ground engaging wheel supported by the wheel support member for rotation about a second wheel axis and to engage the ground surface below the frame thereby supporting the frame above the ground, and the first hydraulic steering cylinder is controllable to steer the second wheel independent of the state of the first hydraulic lift cylinder. In some embodiments, the wheel support member includes an elongated shoulder member including first and second oppositely directed ends where the first and second ground engaging wheels are mounted at the first and second ends of the shoulder member, respectively. 
     In some embodiments, the wheel support member includes an elongated neck member that includes first and second oppositely directed ends, the second end of the neck member is secured to the shoulder member between the first and second ends of the shoulder member, and the first end of the neck member is mounted to the frame for pivotal movement. In some embodiments, the first hydraulic lift cylinder is linked between the shoulder member and the frame. 
     In some embodiments, the wheel support members forms first and second wheel pivot channels, respectively, and the assembly further includes first and second wheel pivot assemblies. The first wheel pivot assembly includes a first pivot pin passing through the first wheel pivot channel and a first pivot arm that extends from and is substantially perpendicular to the first pivot pin. The second wheel pivot assembly includes a second pivot pin passing through the second wheel pivot channel and a second pivot arm that extends from and is substantially perpendicular to the second pivot pin. The steering cylinder is linked to distal ends of each of the first and second pivot arm members. 
     In some embodiments, the assembly includes an intermediate pivot member and first and second arm links. The intermediate pivot member is mounted to the wheel support member to pivot about an intermediate pivot axis, and the first and second arm links link the intermediate pivot member to each of the first and second pivot arms, respectively. A moveable end of the steering cylinder is linked to the intermediate pivot member such that when the steering cylinder is adjusted, distal ends of the first and second arm links move substantially in the same direction. 
     In some embodiments, the assembly includes a lift cylinder anchor member that extends above the frame, one end of the first hydraulic lift cylinder is linked to the lift cylinder anchor member and the other end of the first lift cylinder is linked to the wheel support member. In some embodiments, the frame includes a hitch boom having first and second lateral sides, and the assembly further includes a second hydraulic lift cylinder linked at one end to the lift cylinder anchor member and linked at the other end to the wheel support member, and the first and second lift cylinders are positioned on the first and second sides of the hitch boom, respectively. 
     In some embodiments, the steering cylinder resides below the frame. In some embodiments, the implement is a folding planter with foldable wing booms on either side of the frame. In some embodiments, the assembly includes a control terminal usable to alter the lengths of each of the hydraulic cylinders. In some embodiments, the control terminal is located within a cab of the vehicle. 
     At least some embodiments include an assembly for use with a farm implement towed by a vehicle. The implement includes a main frame and a hitch that extends from the frame for linking to the vehicle. The assembly comprises a T-shaped wheel support member including a neck member and two arm members, the neck member including first and second oppositely directed ends, the arm members extending from the second end of the neck member in substantially opposite directions, the first end of the neck member mounted to the frame for pivotal movement about a substantially horizontal axis, first and second ground engaging support wheels mounted at distal ends of the first and second arm members, respectively, an anchor member extending from the frame, a first hydraulic lift cylinder linked between the anchor member and the T-shaped support member proximate the arm members for adjusting a distance between the arm members and the frame, and a hydraulic steering cylinder mounted to the wheel support member below the frame and linked to the first and second support wheels for controlling steering of the wheels. 
     In some embodiments, the anchor member extends to a distal end on a side of the frame opposite the side on which the steering cylinder is mounted, and the first lift cylinder is linked to the distal end of the anchor member. In some embodiments, the assembly includes an elongated intermediate pivot member and first and second elongated links, the intermediate pivot member is mounted to the wheel support member for pivotal movement at a first end, and linked at a second end to the extendable end of the steering cylinder, the first elongated link is linked to a central portion of the intermediate pivot member at a first end and includes a second end that extends toward the first wheel, and the second elongated link is linked to a central portion of the intermediate pivot member at a first end and includes a second end that extends toward the second wheel. 
     At least some embodiments include a support assembly for facilitating steering, height adjustment and transport of a farm implement towed by a vehicle, and the implement includes a frame. The support assembly comprises a wheel support member linked to the frame to pivot about a first axis, a first hydraulic lift cylinder linked between the frame and the wheel support member, at least a first ground engaging wheel, a first wheel pivot assembly that links to the first ground engaging wheel and defines a first wheel axis of rotation for the first ground engaging wheel, the first wheel pivot assembly being linked to the wheel support member to pivot about a second axis, the second axis being substantially perpendicular to the first axis, and a steering cylinder connected to the wheel support member and linked to the first wheel pivot assembly. 
     These and other objects, advantages and aspects of the invention will become apparent from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown a preferred embodiment of the invention. Such embodiment does not necessarily represent the full scope of the invention and reference is made therefore, to the claims herein for interpreting the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a perspective view of a farm implement including planter row units shown in a working position that is consistent with at least some aspects of the present invention; 
         FIG. 2  is a perspective partial view of the farm implement of  FIG. 1 ; 
         FIG. 3  is a side view of the farm implement of  FIG. 1  in a transporting position of the implement; 
         FIG. 4  is a detail view of the area defined by line  4 - 4  in  FIG. 3 ; 
         FIG. 5  is a detail view of the area defined by line  5 - 5  in  FIG. 6 ; 
         FIG. 6  is a side view of the farm implement of  FIG. 1  in a working position of the implement; 
         FIG. 7  is a top view of a wheel support member of the farm implement with wheel assemblies rotated for a left turn of the implement; and 
         FIG. 8  is a top view of a wheel support member of  FIG. 7  with wheel assemblies rotated for a right turn of the implement. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings wherein like reference numerals correspond to similar elements throughout the several views, and more specifically referring to  FIGS. 1-6 , the present invention will be described in the context of a work vehicle (not shown), such as a tractor, which is linked to a farm implement  10  by an extendable hitch  12 . In this description, the word ‘linked’ should be understood as a connection between components in which the components can rotate relative to one another. In addition to the extendable hitch  12 , the farm implement  10  includes a frame  14 , a lift cylinder anchor member  16 , hydraulic cylinders  36 , a wheel support member  18 , wheel pivot assemblies  44  and  44 ′, a boom support member  21 , and foldable wing booms  22  and  24 . Referring to  FIG. 1 , the foldable wing booms  22  and  24  are shown in dashed lines and may include various types of components that are well known in the art. For example, the foldable wing booms  22  and  24  may include seed planting units. The foldable wing booms  22  and  24  each link to the boom support member  21  to rotate about generally vertical axes to fold forward near the frame  14 . The extendable hitch  12  is provided to increase the distance between the work vehicle and the locations at which the wing booms  22  and  24  pivot so that, when folded forward, the booms can be accommodated between the pivot locations and the work vehicle. Thus, when the wing booms  22  and  24  are folded, the booms do not contact the work vehicle. 
     Referring to  FIGS. 1-6 , the frame  14  includes a hitch boom  23  and a hitch boom bracket  50 . The hitch boom  23 , in some embodiments, is an elongated hollow member with a generally rectangular cross section. The hitch boom  23  includes an upper surface  26 , a lower surface  28 , and lateral sides  30 . The hitch boom bracket  50  includes generally flat sections that connect to the hitch boom  23 , and in some embodiments, more specifically, the lateral sides  30  of the hitch boom  23 . 
     Referring to  FIGS. 1-3  and  6 , the anchor member  16  includes a first support member  25 , a cylinder attachment bracket  32 , a second support member  34 , a locking member  35 , and a spring  37 . The anchor member  16  is generally positioned above the hitch boom  23 . The first support member  25  has a generally rectangular cross section. The first support member  25  extends rearward and above the frame  14  from a first end that connects to the upper surface  26  of the hitch boom  23 . The cylinder attachment bracket  32  connects to a distal end of the first support member  25 . The second support member  34  is similar in structure to the first support member  25 . Unlike the first support member  25 , the second support member  34  extends forward and above the frame  14  from an end that connects to the upper surface  26  of the hitch boom  23 . A distal end of the second support member  25  connects to the cylinder attachment bracket  32 . The locking member  35  is a generally U-shaped member with sections near the upper surface  26  and the lateral sides  30  of the hitch boom  23 . The locking member  35  is linked to the end of the second support member  34  proximate the hitch boom  23 . The spring  37  biases the locking member  35  towards the configuration shown in  FIGS. 3 and 4 . The function of the locking member  35  and the spring  37  will be discussed in further detail below. 
     Referring to  FIGS. 3-6 , each of the hydraulic cylinders  36  includes an extending rod  58 . The hydraulic cylinders  36  are linked to the cylinder attachment bracket  32  and extend rearward and downward therefrom. A single hydraulic cylinder  36  is positioned on each lateral side  30  of the hitch boom  23 . The function of the hydraulic cylinders  36  will be discussed in further detail below. 
     Referring to  FIGS. 1-8 , and as most clearly shown in  FIG. 2 , the wheel support member  18  includes an elongated neck member  38 , an elongated shoulder member  40 , brackets  48  and  72 , two distal connection members  52 , two cylinder rod brackets  54 , two intermediate connection members  56 , a steering assembly  42 , and a linkage assembly  46 . The wheel support member  18  is generally positioned below the hitch boom  23 . In some embodiments, the elongated neck member  38  has a generally rectangular cross section and may be hollow. The elongated neck member  38  extends downward and rearward from a first end proximate the hitch boom  23 . The bracket  48  connects to the end of the elongated neck member  38  proximate the hitch boom  23 . The bracket  48  is linked to the hitch boom bracket  50  for pivotal movement of the wheel support member  18  about a generally horizontal axis below the hitch boom  23 . The bracket  72  connects to the elongated neck member  38  at a position near the distal end of the elongated neck member  38 . 
     Referring to  FIGS. 7 and 8 , the elongated shoulder member  40  of the wheel support member  18  includes two arm members  60  and  60 ′ and two brackets  76 , one of which is connected to each of the arm members. The arm members  60  and  60 ′ extend in generally opposite directions from a position in which the shoulder member  40  rigidly connects to the distal end of the elongated neck member  38 . The arm members  60  and  60 ′ are mirror images of one another, but are otherwise substantially similar components. Therefore, only the arm member  60  will be described here in detail. The arm member  60  may have a generally rectangular cross section and may be hollow. The bracket  76  forms a wheel pivot channel (not shown) and connects to the end of the arm member  60  opposite the distal end of the neck member  38 . 
     Referring to  FIG. 2  and as briefly described above, the wheel support member  18  includes, among other components, two distal connection members  52 , two cylinder rod brackets  54 , and two intermediate connection members  56 . The distal connection members  52  are substantially similar components. The same also applies to the cylinder rod brackets  54  and the intermediate connection members  56 . Therefore, only components on the left side of the farm implement  10  (the visible side as viewed in  FIG. 2 ) will be described here in detail. 
     The distal connection member  52  may have a generally rectangular cross section and may be hollow. The distal connection member  52  connects to the distal end of the elongated neck member  38  and extends in a generally vertical direction there above. As most clearly shown in  FIGS. 4 and 5 , the cylinder rod bracket  54  is a generally trapezoidal-shaped bracket. The cylinder rod bracket  54  rigidly connects to the distal connection member  52 , is linked to the extending rod  58  of the hydraulic cylinder  36 , and can engage the locking member  35 . The function of cylinder rod brackets  54  in connection with the locking member  35  will be discussed in further detail below. The intermediate connection member  56  may have a generally rectangular cross section and may be hollow. The intermediate connection member  56  rigidly connects to a center portion of the elongated neck member  38  and extends in a generally rearward and upward direction there above. The intermediate connection member  56  also rigidly connects to the cylinder rod bracket  54 . 
     Referring to  FIGS. 7 and 8 , the steering assembly  42  of the wheel support member  18  includes a hydraulic steering cylinder  64 , an intermediate pivot member  66 , and first and second elongated links  68  and  70 . The hydraulic steering cylinder  64  includes an extendable rod  74  and is linked to the rear surface of the arm member  60 ′. The intermediate pivot member  66  includes first and second ends and a central portion. In some embodiments, the intermediate pivot member  66  is generally flat and is shaped so that the intermediate pivot member  66  does not contact the distal connection member  52 , as most clearly shown in  FIG. 7 . The first end of the intermediate pivot member  66  is linked to the bracket  72  connected to the elongated neck member  38 . The second end of the intermediate pivot member  66  is linked to the extendable rod  74  of the hydraulic steering cylinder  64 . In some embodiments, the first and second elongated links  68  and  70  are generally identical rod-like members, except the first link  68  is shorter than the second link  70 . Therefore, only the first link  68  will be described here in detail. A first end of the first elongated link  68  is linked to the central portion of the intermediate pivot member  66 . A second end of the first elongated link  68  extends generally in the direction of the arm member  60 . 
     Referring to  FIGS. 2 ,  7 , and  8  and as briefly discussed above, the wheel support member  18  includes, among other components, a linkage assembly  46 . The linkage assembly includes a first link  62 , a second link  84 , and an intermediate member  86 . As most clearly shown in  FIGS. 7 and 8 , the first link  62  is generally trapezoidal and tapers from an end that links to the arm members  60  and  60 ′ to a distal end. As most clearly shown in  FIG. 2 , the second link  84  is generally H-shaped and includes two generally flat side sections connected by an intermediate section. A first end of the second link  84  pivotally connects to the distal end of the first link  62 , and a second end of the second link  84  generally extends towards the hitch boom  23 . The intermediate member  86  is fixed to the second link  84  and engages the first link  62  as shown in  FIG. 2 . The intermediate member  86  permits part of the weight of the farm implement  10  to be supported through the linkage assembly  46 . 
     Referring to  FIGS. 7 and 8 , the wheel pivot assemblies  44  and  44 ′ are mirror images of one another, but are otherwise substantially similar assemblies. Therefore, only the wheel pivot assembly  44  will be described here in detail. The wheel pivot assembly  44  includes two ground engaging wheels  20 , a pin  78 , a pivot arm  80 , and a wheel bracket  82 . The wheel pivot assembly  44  is connected to the wheel support member  18  by the pin  78  that passes through the wheel pivot channel (not shown) of the bracket  76 . The pivot arm  80  extends from the pin  78  and defines a surface that is generally perpendicular to the longitudinal axis of the pin  78 . A distal end of the pivot arm  80  is linked to the second end of the first elongated link  68 . The wheel bracket  82  connects to the pivot arm  80 . The wheel bracket  82  also defines an axis of rotation for, and rotatably connects to, the two wheels  20 . In at least some embodiments, the two wheels  20  rotatably connected to the wheel bracket  82  are offset from one another in the travel direction of the farm implement. 
     Referring to  FIGS. 3 and 6 , boom support member  21  includes elongated members  88 , an upper member  90 , and a lower member  92 . The upper member  90  is fixed to the upper surface  26  of the hitch boom  23 . The lower member  92  is positioned below the lower surface  28  of the hitch boom  23  and is fixed to the upper member  90 . The elongated members  88  are fixed to the lower member  92  and link to the second end of the second link  84 . As discussed above, the boom support member  21  links the foldable wing booms  22  and  24  to the frame  14 . 
     As shown in  FIGS. 3 and 6 , the farm implement  10  can be positioned in different positions that are appropriate for transporting the farm implement  10  and moving components of the farm implement  10  into a working position. The farm implement  10  moves between the transport and working positions by actuating the hydraulic cylinders  36 . Referring to  FIG. 6 , the hitch boom  23  is positioned in a relatively low working position when the extending rods  58  of the hydraulic cylinders  36  are retracted. The working position is suitable for permitting the seed planting units or other components attached to the foldable wing booms  22  and  24  to engage the ground or enter an otherwise appropriate working position. Referring to  FIG. 3 , the hitch boom  23  is elevated further above the ground when the extending rods  58  of the hydraulic cylinders  36  are extended. Extending the rods  58  causes the hitch boom  23  to rotate clockwise slightly as viewed from  FIG. 3 . Similarly, the first link  62  of the linkage assembly  46  rotates clockwise slightly, and the elongated neck member  38  and the second link  84  rotate counter-clockwise slightly when the rods  58  are extended. The elevated position is suitable for elevating components attached to the foldable wing booms  22  and  24  above the ground and transporting the farm implement  10  on a surface other than a field, such as a road. In addition, the elevated position is also a position in which the foldable wing booms  22  and  24  may be folded toward the frame  14  as discussed above. 
     Referring to  FIGS. 3-6 , in some embodiments of the present invention, the cylinder rod brackets  54  engage the locking member  35  when the farm implement is in the elevated/transport position. In some embodiments of the present invention, the locking member  35  must be moved in a clockwise direction, as shown in  FIG. 5 , to permit the hydraulic cylinders  36  to retract and thereby lower the farm implement  10 . The locking member  35  may be rotated by any suitable actuating mechanism, such as a cable that pulls the top section of the locking member  35  and extends toward the work vehicle. 
     In some embodiments of the present invention, the locking member  35  engages the cylinder rod brackets  54  in a manner such that part of the weight of the farm implement  10  is supported through the locking member  35  and the cylinder rod brackets  54  during transport. Therefore, the hydraulic cylinders  36  do not solely support the weight of farm implement  10  in the elevated/transport position. However, the hydraulic cylinders  36  must be extended slightly to disengage the locking member  35  from the cylinder rod brackets  54  before the farm implement  10  is lowered. 
     As discussed above, maneuvering of a farm implement can be difficult when the distance between a work vehicle and the steering wheels of the implement is large. The steering assembly  42  is provided to assist in turning the farm implement  10 . Actuation of the hydraulic steering cylinder  64  results in substantially similar motion of the wheel pivot assemblies  44  and  44 ′. Therefore, only motion of the wheel pivot assembly  44  will be described here in detail. Referring to  FIG. 7 , retracting the rod  74  of the hydraulic steering cylinder  64  causes the first elongated link  68  to move such that the wheel pivot assembly  44  rotates in a clockwise direction (as viewed from above farm implement  10 ). Rotation of the wheel pivot assembly  44  in a clockwise direction leads to a left turn if the farm implement is traveling forward. Referring to  FIG. 8 , extending the rod  74  of the hydraulic steering cylinder  64  causes the first elongated link  68  to move such that the wheel pivot assembly  44  rotates in a counter-clockwise direction. Rotation of the wheel pivot assembly  44  in a counter-clockwise direction leads to a right turn if the farm implement  10  is traveling forward. Operation of the steering assembly  42  advantageously reduces the turning radius of the farm implement  10 . Therefore, the farm implement  10  can be maneuvered through narrow areas. 
     Those skilled in the art will recognize that additional components are needed in conjunction with the hydraulic cylinders  36  and the hydraulic steering cylinder  64 , such as a pump (not shown) and hydraulic conduits (not shown). Any appropriate pump and conduits may be used, provided the pump meets the output requirements to lift and turn the appropriate components of the farm implement  10 . In addition, in at least some embodiments, the hydraulic components are provided such that the hydraulic cylinders  36  may be actuated independently of the hydraulic steering cylinder  64 . 
     In addition, in at least some embodiments, a control terminal (not shown) is provided to control the hydraulic cylinders  36  and  64 . In at least some embodiments, the control terminal is inside a cab (not shown) of the work vehicle. 
     The foregoing description was primarily directed to a preferred embodiment of the invention. Although some attention was given to various alternatives within the scope of the invention, it is anticipated that one skilled in the art will likely realize additional alternatives that are now apparent from disclosure of embodiments of the invention. Accordingly, the scope of the invention should be determined from the following claims and not limited by the above disclosure.