Abstract:
The transversely extending frame of a machine has a number of hingedly interconnected frame sections that may be raised and lowered by lift cylinders to convert the machine between a wide-spread working position and a folded-up transport position. Two lift cylinders for raising and lowering inner wing frame sections relative to the central main frame section are anchored at their inner ends to a hydraulically operated holding cylinder that effectively adjusts the positions of the anchor points of the lift cylinder in a lateral sense. Thus, when the holding cylinder is fully contracted, the inner wing frame sections may be lowered by their lift cylinders until the lift cylinders are fully extended, but the outer ends of the inner wing frame sections remain tilted upwardly to a certain extent. Thus, outer wing frame sections connected to the outer ends of the inner wing frame sections also remain slightly lifted off the ground until fully unfolded from the inner wing frame sections. Thereupon, the holding cylinder may be extended to gently lower all wing frame sections to the ground without damaging tools or mounting components for such tools.

Description:
TECHNICAL FIELD 
   The present invention relates to farm machinery and, more particularly, to machinery that utilizes a multiplicity of frame sections that are hingedly connected to one another for flexing in the field and for permitting fold up for transport, such as typically found in tillage equipment. 
   BACKGROUND AND SUMMARY 
   It is well known in the art to provide wing frame sections on farm machinery such as tillage and planting equipment wherein one or more wing frame sections can be folded up relative to a central main frame section to reduce the overall width of the machine for transport. In some five-section machines, for example, hydraulic cylinders fold outer wing sections almost 180° on top of inner wing frame sections and then other lift cylinders raise the inner wing frame sections into essentially upright positions to provide a compact piece of machinery for over-the-road travel or movement through gates and the like. It is also well known to provide lost motion couplings between the various lift cylinders and their wing frame sections so that, in the field-working position, the frame sections can be hinged relative to one another as need be to accommodate changes in ground contour encountered by the different sections of the machine. While this type of “flexing” action is important during field operations, it can also create problems during unfolding operations, particularly for the outer wing sections. 
   In this regard, the unfolding sequence of a five-section machine, for example, is that the inner wing frame sections are the first to unfold, followed then by the outer wing frame sections. As the inner wing frame sections are lowered down to their working positions and their tools come into ground engagement, their lift cylinders continue to extend an additional amount so as to position the lost motion coupling in an intermediate position, so that the inner wing sections can flex up and down to a certain extent relative to the main section. After the inner lift cylinders are thus fully extended, the outer lift cylinders unfold the outer wing frame sections and place them in the field working position as well. However, if the outer ends of the inner wing frame sections have dipped down slightly because their tools have sunk into soft ground or the ground is inclined, the tools on the outer wing frame sections near the hinge points may dig into the ground and bear an excessive amount of the load as the outer wing frame sections pivot down into their working positions. This is a particular problem where tools such as packer wheels project back from the rear of the outer wing frame sections and are supported by linkage that allows the packer wheels to drop down below the transport wheels on the outer wing frame sections. The gangs of packer wheels may tend to flip up and/or stress the mounting frames and pivot areas of the gangs. 
   The present invention provides a way of holding an inner wing frame section slightly raised while the outer wing frame section is lowered into its transport position, thereby keeping packer wheel gangs or other tools on the outer wing frame section from digging or dragging into the ground as the outer wing frame section approaches its unfolded condition. In a preferred embodiment, the inner end of the inner wing lift cylinder is not fixedly mounted to the main frame section as in conventional arrangements but is instead connected to a holding cylinder that adjusts the anchor point of the inner lift cylinder. Thus, when the holding cylinder is contracted, the anchor point of the inner wing lift cylinder is positioned more inboard that usual, preventing the inner wing frame section from swinging down to a completely horizontal position when the inner lift cylinder is fully extended during unfolding. Therefore, the hinge point for the outer wing section is held in a sufficiently elevated position that the tools of the outer wing section near the hinge point are not allowed to significantly contact the ground as the outer wing frame section unfolds. Once the outer lift cylinder has fully extended, the holding cylinder extends to allow both the inner and outer wing sections to settle down to the ground and place their lost motion couplings in intermediate positions to permit the desired flexing or floating action of the wings relative to the main frame section. 
   In a preferred embodiment, the holding cylinder is connected between the anchor ends of the two inner lift cylinders of a five-section machine so that the holding cylinder helps both sides of the machine. Preferably, in addition to being interconnected by the holding cylinder, the anchor ends of the inner lift cylinders are also attached to the main frame section by swingable lever assemblies. Desirably, the holding cylinder is on a separate hydraulic circuit from the wing lift cylinders, or at least a circuit that can be isolated from other circuitry associated with the wing lift cylinders by sequence valves or the like so that the holding cylinder is always the first to contract during the folding sequence and the last to extend during the unfolding sequence. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a top left front isometric view of a multiple frame section piece of farm machinery constructed in accordance with the principles of the present invention; 
       FIG. 2  is a fragmentary, rear elevational view thereof showing the holding cylinder fully extended and the inner and outer wing lift cylinders also fully extended with their lost motion couplings in intermediate positions to permit independent flexing of the inner and outer wing sections relative to the main frame section; 
       FIG. 3  is a fragmentary rear elevational view of the machine similar to  FIG. 2  but showing the holding cylinder fully contracted while the inner and outer wing lift cylinders remain fully extended, thereby holding the inner wing frame sections in a slightly elevated or upwardly tilted condition; 
       FIG. 4  is a fragmentary rear elevational view of the machine similar to  FIGS. 2 and 3  with the holding cylinder fully contracted and the outer wing lift cylinder partially contracted with the tools of the outer wing frame section off the ground; 
       FIG. 5  is an enlarged, fragmentary top left isometric view of the machine illustrating one of the outer lift cylinders and its lost motion coupling with its outer wing frame section; 
       FIG. 6  is a fragmentary, top left front isometric view of the machine with parts removed for clarity, the holding cylinder being illustrated in its fully extended condition; and 
       FIG. 7  is a fragmentary, top front isometric view similar to  FIG. 6  but showing the holding cylinder fully retracted. 
   

   DETAILED DESCRIPTION 
   The present invention is susceptible of embodiment in many different forms. While the drawings illustrate and the specification describes certain preferred embodiments of the invention, it is to be understood that such disclosure is by way of example only. There is no intent to limit the principles of the present invention to the particular disclosed embodiments. 
   Machine  10  shown throughout the figures may take a variety of different forms. In the illustrated embodiment, the machine is provided with rows of openers  12  (with points removed) that are attached to the frame of the machine for making furrows in the soil as the machine passes over the ground. Gangs of packer wheels  14  are attached to the rear of the frame of the machine and are useful in closing furrows created by openers  12  after seeds or other substances have been deposited in such furrows utilizing delivery means not illustrated. The principles of the present invention are not limited to any particular type of winged machine, and have utility in connection with various types of planters, seeders, fertilizer depositing machines, and straight tillage machines. 
   Machine  10  is provided with a relatively long, transversely extending frame  16  that is supported along the front by a number of ground-engaging wheel assemblies  18 . The packer wheels  14  support the rear of the frame  16  during field operations, and a pair of rear transport wheel assemblies  19  support frame  16  during transport. During field operations, transport wheel assemblies  19  are disposed in raised, standby positions (not shown). Wheel assemblies  18  and packer wheels  14  can be vertically shifted relative to frame  16  so as to raise and lower the latter for depth control purposes during field operations. A tongue  20  extending forwardly from frame  16  has a hitch coupling  22  at its forwardmost end for connecting machine  10  with a towing vehicle (not shown). Wheel assemblies  18  and packer wheels  14  are raised and lowered relative to frame  16  by a number of hydraulic cylinders, including cylinders  24 ,  26 ,  28 ,  30 ,  32  and  34  shown in  FIG. 1 . Cylinders  35  ( FIGS. 6 and 7 ) raise and lower rear transport wheel assemblies  19 . 
   In the illustrated embodiment, frame  16  is divided into five frame sections, namely a center or main frame section  36 , a pair of inner wing frame sections  38  and  40  hingedly connected to opposite outer ends of main frame section  36 , and a pair of outer wing frame sections  42  and  44  hingedly connected to the outer ends of inner wing frame sections  38  and  40  respectively. Inner wing frame sections  38 ,  40  are secured to main frame section  36  by fore-and-aft aligned pivots  46 ,  48 , while outer wing frame sections  42 ,  44  are secured to inner wing frame sections by fore-and-aft aligned pivots  50 ,  52 . 
   Raising and lowering of outer wing frame sections  42 ,  44  relative to inner wing frame sections  38 ,  40  is carried out by a pair of outer lift cylinders  54  and  56  on each inner wing frame section  38 ,  40 . As illustrated in  FIG. 5 , for example, each outer lift cylinder  54 ,  56  is connected at its inner end to an upstanding member  58  on the inner wing frame section  38  or  40  and is connected at its outer end to a swingable, upright lever  60  that forms part of a lost motion coupling  62  with outer wing frame section  42  or  44 . A rigid link  64  is connected between lever  60  on the one hand and an upstanding lug  66  adjacent the outer end of outer wing frame section  42  or  44  on the other hand. Lever  60  is swingable about a fore-and-aft pivot  68  ( FIG. 5 ) between a pair of opposed stops (not shown) associated with the hinge mechanism of outer wing frame section  42  or  44 . Thus, during actuation of lift cylinders  54  and  56 , lost motion occurs as cylinder  54  or  56  moves lever  60  to one or the other of its opposite extremes to make engagement with the corresponding stop. Thereafter, the outer wing frame section  42  or  44  is raised or lowered as the case may be. Such lost motion coupling  62  permits flexing or flotation of outer wing frame sections  42 ,  44  relative to inner wing frame sections  38 ,  40 . 
   Each inner wing frame section  38 ,  40  is raised and lowered by a pair of inner lift cylinders  70  and  72 . The front pair of inner lift cylinders  70  are connected at their anchor ends to main frame section  36  by a rigid bracket  74  that is in turn rigidly affixed to frame  36  by an upstanding truss  76 . At its rod end, each front lift cylinder  70  has a lost motion coupling  78  with its inner wing frame section  38  or  40  so as to allow flexing of such inner wing section relative to main frame section  36 . In a preferred embodiment, each lost motion coupling  78  takes the form of a pair of fore-and-aft aligned, generally horizontal slots  80  in hinge mechanism associated with the inner wing frame section  38  or  40  and a fore-and-aft extending pin  82  in slots  80  that is associated with the rod end of cylinder  70 . Each cylinder  70  thus does not begin to apply a lifting force against its inner wing frame section until pin  82  is against the inner end of slots  80 ; likewise, it does not apply a pushing force against its inner wing frame section until pin  82  is against the outer end of slots  80 . 
   The anchor ends of the rear pair of inner lift cylinders  72  are adjustably, swingably coupled with main frame section  36  by a pair of lever assemblies  84 , each of which comprises a pair of generally upright levers  86  and  88  on opposite fore-and-aft sides of the anchor end of the corresponding cylinder  72 . The upper ends of levers  86 ,  88  are pivotally connected to the anchor end of the corresponding cylinder  72  while the lowers ends of the levers  86 ,  88  are pivotally connected to an upright truss  90  that is fixed to main frame section  36 . Cylinders  72  can thus be adjustably moved toward and away from one another to move their respective anchor ends more inboard or outboard. A double-acting holding cylinder  92  operably interconnects the two anchor ends of cylinders  72  for effecting such adjustment and for holding cylinders  72  in a selected inboard or outboard position. Links  94  pivotally connect the anchor end of cylinder  92  with the anchor end of the right lift cylinder  72 , while links  96  pivotally connect the rod end of cylinder  92  with the left lift cylinder  72 . 
   The outer, rod ends of the rear pair of lift cylinders  72  are connected to their respective inner frame sections  38  and  40  via lost motion couplings  98 . Each coupling  98  is closely similar to the couplings  78  associated with front lift cylinders  70 , comprising an aligned pair of horizontal, fore-and-aft spaced slots  100  in the hinge mechanism associated with the rear pivot  48  and a fore-and-aft extending pin  102  that rides within slots  100  and is fixed to the rod end of cylinder  72 . The limits of lost motion are defined by the opposite ends of slots  100 . 
   The holding cylinder  92  must be capable of operating independently of all of the lift cylinders  54 ,  56 ,  70  and  72 . One way of achieving this result is to have holding cylinder  92  on its own separate hydraulic circuit from that of the lift cylinders. Holding cylinder  92  could thus be actuated manually with its own separate control at the driver&#39;s seat of the towing vehicle. On the other hand, the desired independence could also be achieved by incorporating holding cylinder  92  within the same overall hydraulic circuit as the lift cylinders  54 ,  56  and  70 ,  72  but controlled by appropriate sequence valves or the like to assure that holding cylinder  92  is only extended or contracted at the appropriate times. In this respect, it is important that holding cylinder  92  be the first to contract during a lift sequence and the last to extend during an unfolding sequence. Holding cylinder  92  must be locked in the retracted position so that when the inner wing lift cylinders  70 ,  72  begin to lift on inner wing frame sections  38  and  40  during a fold up sequence, the holding cylinder  92  cannot be pulled out to its extended condition. If sequencing valves are utilized, they can be operated hydraulically, mechanically, or electrically, as well understood by those skilled in the art. The sequence could also be controlled by a computer using position sensors and electric operated valves in accordance with known technology. 
   Operation 
   During field operations the transport wheel assemblies  19  are in their raised, standby positions (not shown) and operating depth is determined by front wheel assemblies  18  and packer wheels  14 . The holding cylinder  92  and the lift cylinders  70 ,  72  and  54 ,  56  are all in their fully extended positions such as illustrated in  FIGS. 1 and 2 . The machine is set up so that with such cylinders fully extended and frame  16  in a level condition as illustrated in  FIG. 2 , the lost motion assemblies  62  for outer wing frame section  42 ,  44  and lost motion assemblies  78 ,  98  for inner wing frame sections  38 ,  40  are in their intermediate positions. For example, pins  82  and  102  of inner lost motion assemblies  78 ,  98  respectively are midway between opposite ends of their slots  80  and  100  respectively. This enables outer wing frame sections  42 ,  44  to flex up and down about their hinges  50 ,  52  relative to inner wing frame sections  38 ,  40  without contracting or extending their lift cylinders as outer wing frame sections  42 ,  44  encounter terrain having different contours than that encountered by inner wing frame sections  38 ,  40 . Similarly, inner wing frame sections  38 ,  40  can flex up and down about pivots  46 ,  48  to a limited extent relative to main frame section  36  without extending or contracting their lift cylinders to accommodate terrain changes not experienced by main frame  36 . 
   When it is time to fold the machine for transport, the front wheel assemblies  18  and packer wheels  14  are fully extended to lift the frame  16  and raise openers  12  out of the ground. Transport wheel assemblies  19  are then lowered to lift the rear of the machine. Holding cylinder  92  is then retracted, until it is totally contracted as illustrated in  FIGS. 3 and 7 . This causes the anchor ends of the rear pair of inner lift cylinders  72  to be pulled closer together, causing pins  102  to be moved to the inboard limits of slots  100  and lifting inner wing sections  38  and  40  slightly off the ground. Because the outer ends of inner wing frame sections  38 ,  40  are tilted upwardly to a certain extent at this time, the lost motion levers  60  associated with outer lost motion couplings  62  move to the outer extremes of their range of travel as outer wing frame sections  42 ,  44  droop downwardly as illustrated in  FIG. 3 . 
   The next step in the sequence is for outer lift cylinders  54 ,  56  to retract, which causes the lost motion levers  60  to be pulled to their inner limits of travel and for outer wing frame sections  42 ,  44  to pivot upwardly about their hinge pivots  50 ,  52  as illustrated in  FIG. 4 . Such contraction of outer lift cylinders  54 ,  56  continues as outer wing frame sections  42 ,  44  swing upwardly into an essentially upright position and then pass over center through an almost 180° arc of travel to lie essentially flatly in an inverted position on top of the inner wing frame sections  38  and  40 . Thereafter, inner lift cylinders  70 ,  72  are retracted to raise inner wing frame sections  38 ,  40  and the superimposed outer wing frame sections  42 ,  44  into an essentially upright position such that the machine becomes generally U-shaped in overall configuration as viewed from the front or the rear. Packer wheels  14  and wheel assemblies  18  on the inner and outer wing frame sections may be retracted at this time to provide a more compact unit. 
   During a subsequent unfolding sequence, holding cylinder  92  remains fully contracted until all of the lift cylinders have been fully extended. Thus, the first step in the unfold sequence, after extending packer wheels  14  and wheel assemblies  18  on the inner and outer wing frame sections, is for inner lift cylinders  70 ,  72  to gradually extend, lowering inner wing frame sections  38 ,  40  with outer wing frame sections  42 ,  44  superimposed thereon, until inner wing frame sections  38 ,  40  are tipped up only slightly above horizontal as illustrated in  FIGS. 3 and 4 . At this time, although inner lift cylinders  70 ,  72  will be fully extended, pins  102  of lost motion assemblies  98  will be at the inboard ends of slots  100 . Next, outer lift cylinders  54 ,  56  are extended to unfold outer wing frame sections  42  and  44 , as illustrated for example in  FIG. 4 . Inner wing frame sections  38 ,  40  remain slightly lifted up at this time so that outer wing frame sections  42 ,  48  completely unfold without inboard tools on the outer frame sections, such as packer wheel  14   a  closest to pivot  52  in  FIG. 4 , contacting the ground and dragging or digging into the soil during the unfolding action. With the outer ends of inner wing frame sections  38 ,  40  held in a slightly raised condition at this time by holding cylinder  92 , the outer ends of outer wing frame sections  42 ,  44  can actually dip down past horizontal to a certain extent as illustrated in  FIG. 3 . 
   Finally, after all of the lifting cylinders  54 ,  56 ,  70  and  72  have been fully extended, holding cylinder  92  extends to allow inner wing frame sections  38 ,  40  to settle down onto the ground into a level condition as illustrated in  FIG. 2 . Preferably, holding cylinder  92  continues to extend sufficiently as to move the pins  102  to midway positions within the slots  100  so as to permit a free floating action on the part of the inner wing frame sections  38  and  40 . Thereafter, transport wheel assemblies  19  are raised and the machine is ready to resume field operations. 
   The inventor(s) hereby state(s) his/their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of his/their invention as pertains to any apparatus not materially departing from but outside the literal scope of the invention as set out in the following claims.