Abstract:
A folding frame farm implement comprising: a) a cart ( 21 ), b) a multi-section rockshaft frame ( 20 ) mounted on said cart and oriented generally transversely in the working position, c) said rockshaft frame ( 20 ) having a central section ( 20   c ) and laterally disposed wing sections ( 20   a   , 20   e ), d) wheel means ( 2,3 ) supporting said rockshaft frame sections, e) said rockshaft frame sections being rotatable about a generally transverse axis between a 1st position and a 2nd position, f) a plurality of individual tool frame sections ( 27, 28 ) rotatably mounted to corresponding ones of said rockshaft frame sections about a generally transverse axis, g) individual wheel support means ( 29, 31 ) for each tool frame section, h) wherein said tool frame sections ( 27, 28 ) are supported at working positions at a variable height above the ground determined by the relative rotational position of the rockshaft frame ( 20 ) between said 1st position and said 2nd position and by the said wheel support means ( 29, 31 ), i) central tool frame section support means ( 31 ) associated with said central rockshaft frame section adapted to retain said central tool frame section ( 20   c ) in close proximity to the ground for transport, j) lift means to further rotate said wring frame tool sections ( 20   a   , 20   c ) from a generally horizontal position to a raised position for transport and k) said wind sections ( 20   a   , 20   c ) being foldable rearwardly for transport.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to tool bar implements used in agriculture to carry ground engaging tools for preparing the ground for planting or for carrying the planter units themselves for planting seed into the ground, and, more particularly, to a tool bar implement that converts from a wide, transversely extending working configuration to a narrow, longitudinally extending transport configuration. 
     BACKGROUND OF THE INVENTION 
     Modem farmers strive to improve the management of increasing amounts of farm acres. Improving management requires farmers to be able to quickly prepare the soil for each season&#39;s farming operations. This haste has driven the need for more efficient and larger farming equipment. 
     Implements such as harrows, packers, or combined harrow-packers were some of the earliest implements to be made with widths exceeding sixty feet in the field operating position. As tractor horsepower has increased over time, larger tillage implements have been made available. These larger implements require a mechanism for compactly folding the implement for practical and safe transport over the highway. 
     The conventional method of folding tillage implements is by folding wing sections along forward aligned axes such that the wings are folded to a generally upright position. Double folding wing sections may have outer sections that fold inwardly and downwardly from the ends of inner wing sections in five section winged implements. In the case of these conventional wing implements, the minimum implement width that can be achieved by such folding is limited by the width of the center section. As a result, road transport may still be somewhat restricted as these implements often exceed twenty feet or more in transport width. 
     Road transport standards in North America are beginning to follow the standards set in Europe in which maximum road transport widths and heights for agricultural implements are being defined. Large implements that have conventional folding wing sections are not able to be folded such that they fall within width and height limits that may be generally 3 meters wide and 4 meters high. Some U.S. states have adopted transport width limits of 13.5 ft. 
     Forward or rear folding implements provide some relief with respect to such transport limits. However, implements must also be made to function with the accurate seeding ability that conventionally folded implements have become capable of. Although some rear or forward folding multibar tillage implements have been developed, they do not demonstrate the accurate depth control required for farming operations. 
     It is therefor desirable to provide a folding tool bar implement that is operable to convert between transport and field operating configurations. 
     SUMMARY OF THE INVENTION 
     Accordingly, an important object of the present invention is to provide a folding tool bar implement that converts between transverse field operating configuration and a longitudinal transport configuration. 
     It is another object of the present invention to provide a folding tool bar implement having a rotatable rockshaft supported on one or more caster wheels. 
     It is a further object of the present invention to provide a caster wheel with a first caster axis and a second caster axis such that the caster wheel caster wheel pivots in all directions on a first caster axis when the implement is in a field operating configuration and may be steerably controlled on a second caster axis by an actuator. 
     It is yet another object of the present invention to provide a caster lock that engages and disengages by gravity. 
     It is a further object of the present invention to provide tool frames that pivot on the rockshaft to follow uneven ground and maintain depth of ground working tools. 
     It is an object of the present invention to provide a folding tool bar implement in which the tool frames are attached to the rockshaft via slotted members such that both pivotal motion and motion along the slot is allowed. 
     It is an advantage of the present invention that the tool frames are raised in sequence so that all the tool frames of all wing sections are not raised at once, thereby minimizing the stress of the rockshaft. 
     It is a further advantage of the present invention that the tool frames in one wing section are all raised at once to minimize the length of hose attachments for hydraulics or air-seed delivery. 
     It is another object of the present invention to provide a limiting linkage that pivots to an over-center position to lock the tool frames when they are fully raised to a transport position. 
     It is yet another object of the present invention to provide springs on the tool frames which abut members on the rockshaft when the tool frames are in the working configuration and which may be used to transfer weight from the rockshaft to the tool frames to bias the tool frames toward the ground. 
     It is a further object of the present invention to provide a transport lock that locks the wing sections adjacent the main section when they are rotated rearwardly for transport. 
     It is another object of the present invention to provide actuators for raising or lowering the wing sections in a range of working positions. 
     It is yet another object of the present invention to provide a link on the rockshaft that operates a hydraulic valve to allow operation of the caster wheels in transport configuration but not in the field operating position. 
     These and other objects, features, and advantages are accomplished according to the present invention by providing a folding tool bar implement that converts from a transversely extending operating configuration to a longitudinally extending transport configuration. The implement includes a rotating rockshaft having a pair of wing sections pivotally connected to the opposing lateral ends of a center section. A plurality of individual tool frames are pivotally connected to the rockshaft sections and extend rearwardly thereof. Each tool frame is also supported by a rearwardly positioned support wheel connected to the rockshaft by a connecting link. The conversion of the tool bar implement begins with the rotation of the rockshaft from a first position to a second position to re-orient the pivot axis connecting the wing sections to the center section into a vertical orientation. The tool frames corresponding to the wing sections are then raised into a vertical orientation so that the wing sections can be pivotally folded rearwardly with the vertical wing section tool frames being positioned over top of the center section tool frames. 
     The foregoing and other objects, features, and advantages of the invention will appear more fully hereinafter from a consideration of the detailed description that follows, in conjunction with the accompanying sheets of drawings. It is to be expressly understood, however, that the drawings are for illustrative purposes and are not to be construed as defining the limits of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein: 
     FIG. 1 is a schematic perspective view of a folding tool bar implement incorporating the principles of the instant invention, the representative tool frames being oriented in a lowered working position with the rockshaft rotated into the first position; 
     FIG. 2 is a schematic perspective view of the folding tool bar implement with the rockshaft rotated into an intermediate position to raise the tool frames into a raised headlands position; 
     FIG. 3 is a schematic perspective view of the folding tool bar implement with the rockshaft fully rotated into the second position and the tool frames being positioned in the non-working position, the tool frames corresponding to the center section of the rockshaft being oriented into a lowered non-working position for compact folding of the implement; 
     FIG. 4 is a schematic perspective view of the folding tool bar implement with the representative tool frames corresponding to the wing sections being raised into a vertical transport position; 
     FIG. 5 is a schematic perspective view of the tool bar frame depicting the left wing section being folded rearwardly into the longitudinal transport configuration such that the tool frames and the ground engaging tools mounted thereon are positioned at least partially over top of the tool frames of the center section; 
     FIG. 6 is a schematic side elevational view of a wing section tool frame and the associated wing section of the rockshaft rotated into the first position with the tool frames being oriented in the lowered working position, corresponding to the orientation depicted in FIG. 1; 
     FIG. 7 is a schematic side elevational view of the wing section tool frame and associated wing section of the rockshaft rotated into the intermediate position to place the tool frame into the headlands position, corresponding to the orientation depicted in FIG. 2; 
     FIG. 8 is a schematic side elevational view of the wing section tool frame and associated wing section of the rockshaft rotated into the second position to place the tool frame into the raised non-working position, corresponding to the orientation depicted in FIG. 3; 
     FIG. 9 is a schematic side elevational view of the center section tool frame and associated center section of the rockshaft rotated into the first position to place the tool frame into the lowered working position, corresponding to the orientation depicted in FIG. 1; 
     FIG. 10 is a schematic side elevational view of the center section tool frame and associated center section of the rockshaft rotated into the intermediate position to place the tool frame into the headlands position, corresponding to the orientation depicted in FIG. 2; 
     FIG. 11 is a schematic side elevational view of the center section tool frame and associated center section of the rockshaft rotated into the second position to place the tool frame into the raised non-working position, corresponding to the orientation depicted in FIG. 3; 
     FIG. 12 is a schematic side elevational view of the folding tool bar implement with the wing section tool frames being raised into the vertical transport position, corresponding to the orientation depicted in FIG. 4; 
     FIG. 13 is a schematic top plan view of the folding tool bar implement in the transverse field operating configuration with the tool frames lowered into the working position, corresponding to the orientation depicted in FIG. 1; 
     FIG. 14 is a schematic top plan view of the folding tool bar implement in the transverse field operating configuration with the tool frames raised into the non-working position, corresponding to the orientation depicted in FIG. 3; 
     FIG. 15 is an enlarged schematic view of the center section of the rockshaft rotated into the second position, the tool frames being removed for purposes of clarity; 
     FIG. 16 is a schematic left front perspective view of the folding tool bar implement in the transverse field operating configuration with the rockshaft in the first position, the left wing section caster wheel being turned as though the implement were making a left turn; 
     FIG. 17 is a schematic left front perspective view of the folding tool bar similar to that of FIG. 16, but with the rockshaft being rotated into the intermediate position to position the tool frames in the headlands position, the left wing section caster wheel being turned as though the implement were making a left turn; 
     FIG. 18 is an enlarged perspective detail view of the wing section caster wheel in a turned orientation as depicted in FIGS. 16 and 17; and 
     FIG. 19 is an enlarged perspective detail view of the wing section caster wheel with the rockshaft rotated into the second position with the caster lockout mechanism engaged to prevent the caster wheel from castering. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIGS. 1-3, an agricultural tool bar implement incorporating the principles of the present invention can best be seen. Any left and right references are used as a matter of convenience and are determined by standing at the rear of the implement and facing forwardly toward the hitch member connecting the implement to a prime mover and, therefore, into the direction of travel. 
     The draft frame  21  is supported for movement in the normal direction of travel indicated by arrow  22  by a conventional hitch mechanism  23  connectable to a prime mover (not shown), such as an agricultural tractor. At the rearward end of the implement frame  23 , a rockshaft  20  is pivotally connected to the draft frame  23  by pivots  24   a ,  24   b  to define a transverse pivot axis  24  about which the rockshaft  20  is pivotable. Conventional hydraulic cylinders (not shown) interconnect the draft frame  23  and the rockshaft  20  to control the pivotal movement of the rockshaft  20  about the axis  24 . 
     FIG. 1 shows the first rotated position of the rockshaft  20 , which corresponds to the lowered working position of the implement with the implement in a transversely extending field operating configuration. In the configuration depicted in FIGS. 1 and 13, the castering first axis  7  of each walking beam assembly  1 , which is described in greater detail below, is generally vertical, thus permitting the walking beam assemblies  1  to freely caster. The rockshaft  20  is formed as having a center section  20   c  supported on a pair of centrally located walking beam assemblies  1   a  and  1   b , as well as being pivotally supported on the implement frame  23 , and at least one wing section  20   a ,  20   b  positioned laterally of the center section  20   c  on each opposing side thereof. The wing sections  20   a ,  20   b  are also supported by walking beam assemblies  1 . 
     The rockshaft  20  is rotatable about the axis  24  to a partially rotated intermediate position depicted in FIG. 2 to raise the tool frames  27 ,  28  into a raised headlands position in which the ground engaging tools (not shown) carried by the tool frames  27 ,  28  are raised just slightly out of the ground to permit a turning of the implement, such as is needed at the headlands of a field. In this intermediate position of the rockshaft  20 , the castering axis  7  of the walking beams  1  is substantially tilted forwardly in the direction of travel  22 . When the rockshaft  20  has been fully rotated into the second position, as depicted in FIGS. 3 and 14, the castering first axis  7  of each walking beam assemblies  1  is turned to a horizontal orientation, whereupon the axis  7  is locked, as will be described in greater detail below, to prevent a castering of the walking beam assemblies  1 . 
     The rockshaft  20  may be configured into a three section member or a five section member, as shown in FIGS. 1-3. For the five section rockshaft  20 , the outermost wing sections  20   a ,  20   e  are pivotally connected by the pivot  25  to the corresponding innermost wing sections  20   b ,  20   d , which is generally horizontal and extending in a longitudinal direction when the implement is in the lowered working position. The innermost wing sections  20   b ,  20   d  are pivotally connected to the opposing ends of the center section  20   c  by a pivot  26  in the same manner in which the outermost wing sections  20   a ,  20   e  are connected to the innermost wing sections  20   b ,  20   d . As best seen in FIGS. 13 and 14, the wing sections  20   a ,  20   b ,  20   d ,  20   e  are retained in the transversely extending field operating position by supports  46  interconnecting the wing sections to the respective sides of the draft frame  21 . 
     The center section  20   c  is provided with a central tool frame  27  pivotally connected thereto and extending rearwardly thereof for pivotal motion about a transverse axis  34 . The central tool frame  27  is also pivotally supported upon a rearward wheel assembly  31  which is pivotable relative to the tool frame  27  about a transversely extending axis  33 . Each wing section  20   a ,  20   b ,  20   d ,  20   e  may carry one or more tool frames  28  (representatively shown by the tool frames  28   a  and  28   b  in FIGS. 1-3 for each of the left side wing sections shown in these Figures). Each wing section tool frame  28  is pivotally connected to the corresponding wing section  20   a ,  20   b ,  20   d ,  20   e  of the rockshaft  20  for relative motion about the transversely extending axis  30  (representatively shown by the pivots  30   a ,  30   b  in FIGS.  1 - 3 ). Each wing section tool frame  28  is also supported by a rear mounted wheel assembly  29  (representatively shown by wheel assemblies  29   a ,  29   b  in FIGS. 1-3) for relative pivotal motion about a transversely extending axis  32  (representatively shown in FIGS. 1-3 as axes  32   a ,  32   b ). 
     Each wheel assembly  29  is connected at a connection point  40  to a link  35  extending forwardly thereof for pivotal connection to the rockshaft  20  at the connection point  39 . The link  35  serves as a four bar linkage to maintain the tool frame  28  generally horizontally and parallel to the ground throughout all working and non-working positions of the tool frame as depicted in FIGS. 1-3. The rotation of the rockshaft  20  from the first position toward the second position, as is shown in FIGS. 1-3 and  6 - 8 , raises the forward end of the tool frames  28  and pulls the tool frames  28  forwardly. The links  35  cause rotation of the wheel assemblies  29  about the axis  32  to raise the rearward end of the tool frames  28  correspondingly, thereby maintaining the tool frame  28  parallel to the ground. 
     Referring now to FIGS. 4 and 5, the wing section tool frames  28  may be further rotated about the axes  30  relative to the rockshaft  20  to orient the tool frames  28  into a vertical transport position, whereupon the support wheels  29  are lifted clear of the ground and will pivot about the axis  32  to lie adjacent to the tool frame  28 . The tool frames  27  corresponding to the center section  20   c  of the rockshaft  20  are not rotated vertically to convert the implement into a transport configuration. Instead, the tool frames  27  remain generally horizontally disposed in a lowered non-working position, as will be described in greater detail below. 
     Once the wing section tool frames  28  have been raised into the vertical transport position, the rockshaft  20  having been rotated into the second position to re-orient the axis  26  into a vertical orientation, the wing sections  20   a ,  20   b ,  20   d ,  20   e , can be folded rearwardly about the pivot axis  26  to orient the wing sections in a longitudinal direction so that the transport width of the implement is primarily determined by the transverse length of the center section  20   c  of the rockshaft  20 . Preferably, the support wheel assemblies  29  and wing section tool frames  28  are raised sufficiently in the transport position to clear over top of the central section tool frames  27 . 
     Referring now to FIGS. 6-8, the wing section tool frames  28  and the associated wing section  20   c  of the rockshaft  20  can best be seen. In FIG. 6, the lowered working position of the tool frame  28  is depicted. The rockshaft  20  is rotated to the first position. A hydraulic cylinder  36  interconnects the rockshaft  20  at connection point  37  and the tool frame  28  at the connection point  38 . As can be seen in FIGS. 7 and 8, the hydraulic cylinder  36  extends as the rockshaft  20  is rotated from the first position toward the second position, thus keeping the tool frame  28  in a generally horizontal orientation. The link  35  interconnecting the rockshaft  20  and the wheel assembly  29  also maintains the tool frame  28  in the generally horizontal orientation. Once the rockshaft  20  has pivoted into the second position, as depicted in FIG. 8, the hydraulic cylinder  36  has fully extended with the tool frame  28  in the raised non-working position. The movement of the tool frames  28  into the vertical transport position as shown in FIG. 12 is accomplished by a contraction of the hydraulic cylinder  36  after the rockshaft  20  has been rotated into the second position. 
     Referring now to FIG. 9, the center section tool frame  27  also moves between a lowered working position when the rockshaft  20  is rotated into the first position; a headlands position (shown in FIG. 10) when the rockshaft  20  is rotated into an intermediate position; and a raised non-working position when the rockshaft  20  is rotated into the second position. The center section tool frame  27 , however, is connected at a pivot point  41  carried by the center section of the rockshaft  20  within a slot  42 . A link  44  interconnects the pivot  41  to the draft frame  21  to control the position of the pivot  41 , and thus the tool frame  27 , within the slot  42 . Accordingly, the rotation of the rockshaft  20  into the second position moves the center section tool frame  27  into a raised, non-working position that is oriented lower than the corresponding non-working positions of the wing section tool frames  28 . The link  35  is also mounted on the rockshaft  20  for movement corresponding to the movement of the pivot  41  within the slot  42  so as to effect pivotal movement of the support wheel assembly  31  to maintain the tool frame  27  parallel to the ground. 
     Thus, when the wing sections  20   a ,  20   b ,  20   d ,  20   e , are folded rearwardly with the wing section tool frames  28  raised into the vertical transport position, the center section tool frame  27  is lowered to permit the wing section tool frames  28  to locate over top of the center section tool frame  27 . However, as best seen in FIG. 10, the rotation of the rockshaft  20  into the intermediate position to move the tool frames  27 ,  28  into the headlands position does not move the pivot point  41  sufficiently in the slot  42  to cause a substantial difference in height for the center section tool frame  27  as compared to the counterpart wing section tool frames  28 . As depicted in FIG. 12, the wing section tool frames  28  are raised into the vertical transport position while the center section tool frame  27  is maintained at the lowered non-working position. 
     The details of the rockshaft  20  can best be seen in FIG. 15 wherein the center tool frame section  20   c  is shown in its fully rotated second position. In this position the center section tool frame  27  would be supported in the lower extremity of slot  42 . Preferably, the rockshaft  20  may be locked into this second position by the interaction of a locking arm  48  with an abutment  47  carried by the draft frame  21 . The position of the locking arm  48  is controlled by the arm  49  of an L-shaped rotatable member  50  connected to a manually operated control lever  52  by a linkage  51 . 
     The details of the walking beam assembly  1  are best seen in FIGS. 16-19. The walking beam assembly  1  includes a pair of wheels  2 ,  3  supported in walking arrangement on a common axis of rotation  4 . Each of the wheel axles  2   a ,  3   a  are offset from the axis of rotation  4  by an equal amount. All axes of rotation  2   a ,  3   a ,  4  are coplanar. The walking beam assembly  1  is supported on a first member  5  for rotation about the axis  4 . The first member  5  is pivotally supported on a second member  6  for rotation about the castering first axis  7 . In the various working positions, including the headlands position, of the tool frames  27 ,  28 , the castering first axis of rotation  7  is maintained substantially vertical, wherein the support member  5  is permitted to freely caster about the castering axis  7  while supporting the second member  6  on the walking beam assembly  1 . 
     Preferably, the second member  6  is L-shaped so as to provide adequate clearance for the wheels  2 ,  3  to flip over in the working position without interference from either the first or second members  5 ,  6 . The second member  6  is further rotatably supported on the rockshaft  20  for rotation about a second axis  10 . In the working positions, shown in FIGS. 16-18, the second member  6  is hydraulically locked by the hydraulic actuator  11  interconnecting the rockshaft  20  and the second member  6  through the flange  12  to prevent rotation about the second axis  10  which remains substantially horizontally oriented throughout the working positions of the tool frames  27 ,  28 . Furthermore, throughout the working positions of the tool frames  27 ,  28 , the castering action of the first member  5  about the castering axis  7  is unimpeded. 
     Rotation of the rockshaft  20  into the second position, as depicted in FIG. 19, brings the castering axis  7  into a substantially horizontal position next to the ground and moves the second axis  10 , corresponding to the leg of the second member  6 , into a generally vertical orientation. A latch tongue  14  is rotated about its pivotal attachment  16  to the first member  5  by gravity so as to engage the latch  15  to prevent rotation of the first and second members  5 ,  6  about the castering axis  7 . The second member  6  is capable of rotation about the now vertical axis  10  to steer the wheel assembly  1  as will be necessary for reorientation of the walking beam assembly  1  when the wing sections are folded into a longitudinally extending transport configuration. The rotation of the rockshaft  20  back into the first position reorients the castering axis  7  into a vertical orientation and the second axis  10  into a horizontal orientation and causes the latch tongue  14  to disengage the latch  15  by gravity to permit movement of the first and second member  5 ,  6  about the castering axis  7 . 
     The invention of this application has been described above both generically and with regard to specific embodiments. Although the invention has been set forth in what is believed to be the preferred embodiments, a wide variety of alternatives known to those of skill in the art can be selected within the generic disclosure. The invention is not otherwise limited, except for the recitation of the claims set forth below.