Abstract:
A farm implement convertible between a work position and a transport position is disclosed. In the transport position, a compact package is formed less than eight feet in width and less than 14 feet in height. Right and left wings connected to the main frame may be raised by pushing articulated arms a short distance to fold the wings above the main frame.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to transportable farm implements. Although the title designates the preferred embodiment of a disc harrow, the apparatus is suitable for suspending any number of work tools from the structure, such as sprayers, fertilizers, planters, tillers, etc. The apparatus is convertible from a working mode, in which wings are spread to a maximum width to permit farm operations to cover a wide swath with each pass, and a transport mode, in which the wings are folded into a compact width and height such that is can legally be transported on roads and highways without special permits, escorts, lighting, or hours of transporting.  
         BACKGROUND OF THE INVENTION  
         [0002]    The prior art contains numerous patents for farm implements that are convertible between a transport mode and a use mode. Thus, U.S. Pat. No. 5,715,893 discloses a towable farm implement having wings that are lifted on a turntable and rotated 90 degrees, so that the wings that extend laterally in the use mode are lifted and rotated to fore and aft positions extending from the turntable. FIG. 9 of that patent shows a long tongue member  24  for hitching to a tractor to tow the implement from a storage location to a use location. Such an apparatus could not be transported on a highway from a manufacturing site to a customer without special permits, escorts and hours of transportation. There is a need for a farm implement that can be shipped from manufacturer to farmer by common carrier on highways without the need for escorts, special permits, flashing lights or restricted hours of transport.  
           [0003]    U.S. Pat. No. 4,159,038 discloses an earthworking implement having foldable wings to allow movement of “implements that are over ten meters or more wide from one field to another” (column 1, lines 15-16). Road-legal limits vary from jurisdiction to jurisdiction, but commonly a load cannot be more than eight feet wide nor more that fourteen feet above the road, much less than the dimensions of the load in this patent. Similarly U.S. Pat. No. 3,692,121 shows liftable wings that can be raised to a position over the main frame, but the main frame is not road-legal, so the apparatus cannot be transported over the highway from the manufacturer to the user without special permits. Both of these prior art patents use fluid cylinders of long thrust to lift the wings (82 in the &#39;038 patent and 42 in &#39;121).  
           [0004]    Likewise, U.S. Pat. No. 4,479,554 has a main frame that is not road-legal, so lifting the wings cannot make it road-legal. Moreover, a piston cylinder  110  has a long thrust in this patent. There is a need for a road-legal apparatus that can be folded compactly by means of a short thrust cylinder.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention provides a road-legal farm implement that can be expanded to work a wide swath by activating a fluid pressure cylinder powered by the hydraulic system of the towing vehicle as is common in the art. A bridge above the main frame holds a fluid cylinder that pushes lifting arms to raise wings to a location above the main frame within a road-legal envelope. The basic frame is approximately eight feet in width with dependent work implements. The wings, when lowered to the work position, extend approximately eight feet each, one laterally extending forward of the main frame and the other extending laterally rearward from the main frame. Two sets of wings may be added to a tandem harrow on the main frame. Each wing is raised by a single small hydraulic cylinder with a stroke as short as eight inches and a bore of approximately three inches. When in the transport position, wheels located in width slightly less than the road-legal width provide maximum stability while being transported. All wings are folded above the wheels so that no part of the wings or other elements of the apparatus extends beyond the plane formed vertically from the outer edges of the wheels.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    [0006]FIG. 1 is an isometric view of the main frame that supports the apparatus.  
         [0007]    [0007]FIG. 2 is a front elevation view of the front wing assembly and main gang in the work position.  
         [0008]    [0008]FIG. 3 is an isometric view of the bridge assembly.  
         [0009]    [0009]FIG. 4 is a front elevation view of the front wing assembly and main gang in the transport position.  
         [0010]    [0010]FIG. 5 is an isometric view of the hitch assembly.  
         [0011]    [0011]FIG. 6 is an elevation view of an alternate hold-down assembly. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0012]    [0012]FIG. 1 illustrates the main frame  11  that rides on a sufficient number of wheels with pneumatic tires to support the weight of the apparatus. I have found that four 15″×18″ wheels  12 ,  13 ,  14  and  16 , mounted on axle  17  transversely to the main frame  11  are sufficient to support the weight of the apparatus in the transport mode. 9.5L tires are suitable. Axle  17  rides on axle blocks, one of which is shown at  18  in FIG. 1. Wheels  12 ,  13 ,  14  and  16  are rotatable from a tilling position in which the work implements engage the soil (the “up” position) and a transport position in which the wheels engage the surface being traversed (the “down” position). As shown in FIG. 1, axle block  18  carries blocks  19  which support rod  20 . Welded plates  15  engage rod  20  to permit rotation of rod  20  between the up position and the down position. Each wheel  12 ,  13 ,  14  and  16  rotates about an axle  17 , which is carried on plate  15  attached to rod  20 , which rotates in the series of blocks  19 , to place wheels and implements in the desired transport or work position.  
         [0013]    Frame  11  consists of two main parallel rails  21  and  22  inboard of the outer wheels  12  and  16  as the primary load bearing elements running longitudinally front to rear. At the front ends of rails  21  and  22  are hangers  26  and  27  from which a conventional hitch (not shown) depends for towing by a tractor or other towing vehicle. Outboard of the rails  21  and  22  are stabilizers  23  and  24 . Stabilizer  23  carries axle block  18  and encloses wheel  12  to provide maximum stability in the transport mode. Stabilizer  23  also supports the wing assemblies presently to be described in a manner to minimize roll in the transport mode. Stabilizer  24  operates in the same way as stabilizer  23 , but on the right side.  
         [0014]    Rails  21  and  22  are separated by forward cross member  28  and rear cross member  29 . Forward cross member  28  supports a center mount  31  for the hitch (not shown). Rail  21  supports gang attachment  32  for the forward gang of discs or other farm implements supported by the main frame. Multiple holes in gang attachment  32  allow for adjustable angles for the main gang relative to the direction of towing in the work position. A pin (not shown) permits the user to select the desired hole for the angle needed for the work task, as is conventional. Gang attachment  33  is mounted on the rear of rail  21  to accommodate the rear gang of work implements attached to the main frame. Following discs on tandem harrows typically require less adjustment, so rear gang attachment  33  has fewer holes.  
         [0015]    Between main rails  21  and  22  are inboard rails  36  and  37  that support a conventional wheel raising apparatus to lift the wheels from the lower transport position to the raised work position in which the discs or other farm implements can engage the soil. Wheel  13  rides between rail  21  and rail  36 , and wheel  14  rides between rail  37  and rail  22 . A conventional hydraulic wheel raising attachment (not shown) is mounted on rails  36  and  37  at rear mount  38  and forward mount  39 . Because the load in raising the wheels is primarily borne on the front mount  39 , there are additional wheel-raising cross members  41  and  42  to carry the load to the main rails  21  and  22 .  
         [0016]    [0016]FIG. 2 illustrates the front wing assembly  46  in the work position with wings  47  and  48  extended from main gang  49  in a continuous array of work implements. Each of wings  47  and  48  and main gang  49  has a desired number of discs or work implements dependent therefrom. FIG. 2 only shows two discs rotatable in blocks  51  and  52 , but it will be understood that any number of implements and blocks may be attached to gangs  47 ,  48  and  49 . As is conventional in tandem disc harrows, the forward discs turn soil over in one direction and rear discs turn the soil in the opposite direction. Accordingly, the rear wing assembly (not shown) is identical to the front wing assembly in FIG. 2 except that the discs are in the opposite direction.  
         [0017]    Wings  47  and  48  each have brackets  53  and  54 , respectively, welded to the beam to provide pivot pins  56  and  57 , respectively, for raising the wings  47  and  48 . Brackets  53  and  54  allow the main frame  11  (FIG. 1) to extend between brackets  53  and  54  above main gang  49 , which is releasably attached to the main frame (not shown in FIG. 2). Each of brackets  53  and  54  is attached by one or more bolts  58  and  59  to bridge assembly  61  spanning the space above main frame  11  and anchoring pivot pins  62  and  63  about which upper arms  64  and  66  pivot.  
         [0018]    Upper arms  64  and  66  are connected, through elbows  67  and  68 , respectively, to lower arms  69  and  71 , which are, in turn, attached to braces  72  and  73 , respectively, welded to wings  47  and  48 . Braces  72  and  73  have holes into which pins  74  and  76  are inserted to provide pivot points for lower arms  69  and  71 , respectively.  
         [0019]    Lifting of wings  47  and  48  is accomplished by hydraulic cylinders  77  and  78  for each wing connected to the hydraulic system of the towing vehicle. Cylinders  77  and  78  are relatively small, given the weight of the apparatus, and achieve the lifting task by pushing upper arms  64  and  66  upwardly about pivot points  62  and  63 . I prefer a hydraulic cylinder with a stroke of less than 12 inches, with an 8 inch stroke and 3 inch bore being optimum. The cylinders  77  and  78  are shown in FIG. 2 in a closed position, with the rod of cylinder  77  attached to pin  79  through a projection in upper arm  64 . Likewise, Cylinder  78  is attached to pin  81  in a projection of upper arm  66 . Cylinder  77 , at its lower end, is attached to pin  82  in bracket  53 . Cylinder  78  has a corresponding pin  83  in bracket  54 .  
         [0020]    When cylinders  77  and  78  are activated, they push upper arms  64  and  66  upwardly through pins  79  and  81 , respectively to cause arms  64  and  66  to rotate about pins  62  and  63 . Lower arms  69  and  71  also raise, pivoting about elbows  67  and  68 , at the upper end, and pins  74  and  76  at the lower end. The movement of only eight inches of the piston rods in cylinders  77  and  78  is sufficient to raise wings  47  and  48  to a position for transport inside the vertical plane defined by the outer limits of stabilizers  23  and  24  (FIG. 1).  
         [0021]    [0021]FIG. 3 is a detail of the bridge assembly  61  shown in FIG. 2. Bridge  61  has two parallel plates  85  and  86  of identical configuration. One or more holes  58  and  59  are formed in the outward ends of the plates  85  and  86  to adjustably attach to corresponding holes  58  and  59  in brackets  53  and  54  (FIG. 2). Plates  85  and  86  are connected by welded plates  87 ,  88  and  89  to keep them rigidly parallel. The pivot pins  62  and  63  of FIG. 2 are accommodated by tubes  91 ,  92 ,  93  and  94  aligned with holes  96  and  97  in plate  85 . Corresponding holes (not shown) are in plate  86 . This reinforcement serves to enhance the main load-bearing pivot pins  62  and  63 .  
         [0022]    [0022]FIG. 4 shows the assembly of FIG. 2 in a folded position for transport. Cylinders  77  and  78  have their rods  101  and  102  extended less than twelve inches. This raises upper arms  64  and  66  by pushing on pins  79  and  81  attached to projections on arms  64  and  66 . Lower arms  69  and  71  extend between elbows  67  and  68  and pins  74  and  76  in braces  72  and  73 , respectively. In the folded position, locking pins  103  and  104  pass through each of lower arms  69  and  71  and braces  72  and  73  to prevent wings  47  and  48  from accidentally jarring loose from the folded position.  
         [0023]    [0023]FIG. 5 illustrates the hitch assembly  105  for towing the apparatus in either the work position or the folded transport position. Parallel plates  106  and  107  are welded to cross member  108  forward of main frame  11  (FIG. 1). In FIG. 1, the left side is the forward end of the frame and the right side is the aft end of frame  11 . In FIG. 5, however, the left side is the aft end of the hitch assembly  105  and the right side is the front end, the opposite of FIG. 1. Thus, forward facing U-shaped brace  110  has holes  111  and  112  that permit a pin (not shown) to extend through each hole and tube  113  at the front end of hanger  26  (FIG. 1) to secure the left side of the hitch to the left side of the main frame  11 . Similarly, U-shaped brace  116  on hitch assembly  105  extends rearwardly to embrace hanger  27  and tube  114  (FIG. 1) to permit a pin (not shown) to extend between holes  117  and  118  through tube  114 , whereby the right side of hitch assembly is attached to hanger  27  of frame  11 . A plurality of holes  121  permit the hitch assembly  105  to be adjustably secured to the towing vehicle for the desired pitch of the working implements in relation to the ground. Hole  122  allows a pin to attach a tongue (not shown) connecting the hitch to the towing vehicle.  
         [0024]    [0024]FIG. 6 shows an alternate hold-down assembly to hold down wings in the work position, while permitting them to flex when being raised or lowered. As illustrated in FIG. 2, lower arm  71  is secured to brace  73  by means of pin  76 . While this configuration is suitable for work applications, it does not permit the wing  48  to flex as it is being folded up or down. In a preferred embodiment, I use an additional hold-down assembly  126  outboard of the brace  73 . Assembly  126  consists of an arm  127  extending between a riser  128  secured to wing  48 , as by welding. Arm  127  pivots on pin  129  extending through riser  128 . Arm  127  is in two parts separated by turnbuckle  131 , allowing the two parts to be adjusted in length. Arm  127  extends through box  132 , consisting of two parallel welded plates, only one of which is shown at  133 , secured to wing  48 , as by welding. Arm  127  slidably passes through the box  132  as the wing  48  flexes during raising and lowering. Box  132  is formed by the two plates  133 , upper pin  134  and lower pin  136  separating the plates  133 . Given the length of wing  48  and the flexibility of steel, arm  127  can be adjusted by turnbuckle  131  to allow arm  127  to pass through box  132  to the extent necessary. When the wing  48  is lowered to the work position, it may be held down solid and immovable by placing a pin (not shown) in hole  137 . The pin engages box  132  to prevent arm  127  from sliding through between plates  133 , making it immovable, barring the flexing of wing  48  in the work position.  
         [0025]    The road-legal requirements for transporting on roads and highways vary by jurisdiction. It is the intent of this invention to comply with the legal requirements of all jurisdictions. As an example, many jurisdictions will permit loads on roads without escorts, wide load signs, or special permits if they do not exceed eight feet in width nor fourteen feet in height. However, because these limitations may change over time, I do not want to be limited to this particular example.  
         [0026]    The embodiments described above have been described with particularity to enable one skilled in the art to make and use them. Modifications and changes from these embodiments may be made by one having ordinary skill in the art without departing from the inventive concepts defined in the claims.