Abstract:
A row following apparatus that attaches to the forward portion of the frame of a tractor towed harvester or cultivator which operates to monitor and adjust the position of the harverster. The row following apparatus uses a pair of pivotally attached sensing feet for following the crop rows. These sensing feet are attached to the frame of the present invention by a pair of automotive style ball joints. The use of the ball joints allows the pivotal movement of the sensing feet in a 360 degree manor that is unattainable with other methods of attachment.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to an improvement in the methods used to control the position of farm implements, such as harvesters, relative to the location of the individual plants of a row crop within which the implement is being employed. More specifically, to a method of automatically adjusting the relative position of such implements in regards to the row crop without requiring the operator to make constant adjustments to the attitude of the towing vehicle. 
   The production of row crops such as sugar beets requires the use of specialized farm implements such as cultivators and harvesters that are drawn through the field during cultivating and harvesting operations. These procedures require that the farm implements be properly oriented at all times relative to the individual plants and their related rows comprising the row crop. This requirement creates difficulties as it is very hard for the operator of the towing vehicle to maintain the proper orientation as he travels up and down the row crop both because the rows are never completely straight and the towing vehicle may tend to wander relative to a straight line due to surface conditions or problems in the directional control apparatus of the towing vehicle. The potential wandering of the tow vehicle is transferred to the towed implement leading to positional variances in the horizontal plane between the implement&#39;s diggers the plants constituting the row crop. These horizontal variances often lead to damage to the crop as the diggers can be far enough off line to result in a destroyed or entirely missed plants. 
   Additionally, variances in the level or composition of the field surface can create problems in the vertical orientation of the towed implement causing the attached diggers to dig too deeply or to skip over entire sections of the row crop. Again, this misalignment in the vertical orientation can result in damage to the crop and implement or to a situation where sections of the row crop are left uncultivated or unharvested in the field, either of which are undesirable to the farmer. 
   In the past many possible solutions to these problems have been proposed, some of which are illustrated in the prior art. The most relevant of these for the purposes of the present invention is illustrated in U.S. Pat. No. 4,031,962 issued to Ellinger which describes an apparatus to control both the vertical and horizontal orientation of a harvester to which it is attached. The provided apparatus operates by the use of a pair of elongated sensing shoes that are positioned below the harvester so that they run along the surface of the ground during field operations in a manner so that each of the individual sensing shoes pass on opposite side of the row crops measuring changes in both the vertical and horizontal orientation of the row crop and making the appropriate adjustments to the relative position of the towed implement. 
   While the described apparatus accomplished its stated goals, a problem with its design results in deficits in its sensitivity and responsiveness that limit its overall effectiveness in the function for which it was designed. This problem is a result of the manner employed to pivotally attach the sensing shoes to the remaining portion of the apparatus in that they are not freely pivotal in all axises and therefore limited in their range of motion. This method of construction results in an apparatus that is less sensitive and responsive than is desirable and therefore, of limited value to the row crop farmer. 
   Therefore, it can be seen that it would be desirable to provide a mechanism which monitors the vertical and horizontal position of a towed implement and its attached diggers relative to the individual plants and rows of a row crop such as sugar beets. Additionally, that this apparatus be sensitive enough to accurately guide the harvester or other like implement through the rows of a row crop to maximize its operational potential in field operations. 
   SUMMARY OF THE INVENTION 
   It is the primary objective of the present invention to provide a method by which the position of a tractor drawn harvester or cultivator type farm implement, relative to the individual rows of a row crop such as sugar beets, can be constantly monitored and adjusted to ensure that the towed harvester is maintained in the proper position enabling it to perform its designed function at the highest degree of accuracy possible. 
   It is an additional objective of the present invention to provide such a method of positioning a towed farm implement that will automatically make the necessary adjustments in its position relative to the row crop without the need for any major corrective inputs from the operator of the towing tractor while working the field. 
   It is a further objective of the present invention to provide such a method of positioning a towed farm implement which is equipped with a pair of sensing feet that are pivotally mounted in a manner which allows for the greatest degree of pivotal flexibility providing them with a means by which they can be employed to monitor the position of the farm implement to the highest degree of accuracy possible which will translate to it operating at its greatest possible potential and result in higher crop yields. 
   These objectives are accomplished by the use of an apparatus that attaches to the forward portion of the frame of a tractor towed harvester or cultivator which operates to monitor and adjust the position of the harvester or cultivator in relation to the orientation of the row crop. In this purpose, the present invention is comprised of a vertically oriented frame to which is pivotally attached at its lower end a pair of sensing feet which run along the surface of the field during harvesting or cultivating operations. 
   The pivotal attachment of the sensing feet to the frame of the present invention is accomplished through the use of a pair of automotive style ball joints. The use of the ball joints provides a degree of sensitivity and accuracy to the invention that is unattainable with other methods of attachment. The reason for this is that while the body, or socket portion, of the ball joint is fixedly attached the frame of the invention, the ball portion and the attached sensing feet are free to pivot in any direction below the lip of the body portion of the ball joint. This means that any deflection of the sensing feet either in their vertical orientation through their contact with inconsistencies in the surface of the field or in its horizontal orientation through their contact with the relevant row of the row crop will be identified and compensated for by the adjustment of the towed implement. 
   The methods used to make these adjustments to the orientation of the harvester or cultivator are accomplished through the use of a hydraulic system comprised of a pair of sensing valves that are each in turn connected to a corresponding hydraulic cylinder. The hydraulic pressure that is necessary to operate this system is supplied through a connection to the towing vehicle&#39;s hydraulic system and is transferred to the appropriate components through a plurality of hydraulic pressure and return lines. This hydraulic pressure is employed to operate the hydraulic cylinders which in turn make the required adjustments to the orientation of the harvester or cultivator in relation to the row crop. 
   These adjustments are made in the horizontal plane when the sensing feet are deflected to one side or the other as a result of their contacting an obstacle. The described deflection of the sensing feet is transferred through a linkage to the horizontal sensing valve which in turn directs the flow of hydraulic pressure to the horizontal hydraulic adjustment cylinder. The horizontal hydraulic cylinder then expands or contracts to alter the angle of attack of the harvester or cultivator in relation to the towing vehicle. This corrective action is constantly taking place to ensure that the implement is always in the proper orientation with respect to the row crop that is being harvested or cultivated. 
   Additionally, the vertical plane adjustments are accomplished through a detected variance in the vertical orientation of the sensing feet which is transferred to the vertical sensing valve through a connecting linkage. These vertical variances are then transferred to the vertical adjustment cylinder through the hydraulic pressure and return lines. The vertical adjustment cylinder then adjusts the vertical orientation of the harvester or cultivator through its expansion or contraction which raises or lowers the diggers attached to the implement frame in relation to the surface of the field. The use of this system ensures that the diggers are constantly maintained in the proper orientation with respect to the field enabling the harvester or cultivator to operate at its maximum potential at all times. 
   For a better understanding of the present invention reference should be made to the drawings and the description in which there are illustrated and described preferred embodiments of the present invention. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a generalized towed farm implement illustrating the manner in which the present invention is connected to it. 
       FIG. 2  is a top elevation view of a generalized towed farm implement illustrating the relative position of the present invention in relation to the major components of the farm implement. 
       FIG. 3  is a side elevation view of the farm implement of  FIG. 2  further illustrating the position of the present invention in relation to the major components of such an implement. 
       FIG. 4  is a side elevation cut-away view of the present invention taken along line  3  of  FIG. 2  illustrating the orientation of its major components and further detailing the method used to attach it to the pivot frame of the farm implement. 
       FIG. 5  is a reverse side elevation cut-away view of the present invention of  FIG. 4  and illustrates its components that are not visible in the previous illustration. 
       FIG. 6  is a top elevation view of the sensing feet components of the present invention illustrating their manner of construction and their orientation in the neutral or closed position. 
       FIG. 7  is a top elevation view of the sensing feet components of the present invention of  FIG. 6  and illustrating their orientation when in the open position. 
       FIG. 8  is a top elevation cut-away view of the sensing feet components of the present invention taken along line  4  of  FIG. 4  and illustrating their orientation when they are in the neutral horizontal position. 
       FIG. 9  is a top elevation cut-away view of the sensing feet components of the present invention taken along line  4  of  FIG. 4  and illustrating their orientation when they are in the activated horizontal position. 
       FIG. 10  is a side elevation view of the sensing feet components of the present invention illustrating their orientation when in the neutral vertical position. 
       FIG. 11  is a side elevation view of the sensing feet components of the present invention illustrating their orientation when in the engaged vertical position. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to the drawings, and more specifically to  FIGS. 1 ,  2 , and  3 , the positioning control apparatus  10  is a device that connects to towed farm implements such as a harvester  12  or other similar devices and is employed to keep the harvester  12  in the proper alignment when a farmer is working in a row crop. For the purpose of simplicity, the positioning control apparatus  10  herein illustrated is represented as used in conjunction with a harvester  12  but it must be noted that it would work equally well with any towed implement commonly used in the working of row crop fields. Additionally, the illustrated harvester  12  is intended to represent a generalized form of harvesters and is not intended as a depiction of a specific type of implement. 
   The harvester  12  is generally made up of two connected frames. The most forward of these is the primary frame  14  which is the portion of the harvester  12  employed to attach it to the towing vehicle and from which the second portion, the pivoting frame  16 , extends rearward from. The primary frame  14  consists of lower frame member  20  which is a horizontally oriented rectangular tube that extends across the most forward end of the harvester  12  in a perpendicular manner. The upper surface of the lower frame member  20  is equipped with a plurality of upwardly extending vertical frame members  24  which are in turn attached at their upper end to the lower surface of the upper frame member  22 . Thus, the lower and upper frame members,  20  and  22 , form a vertically oriented rectangular box which creates the base upon which the remaining components of the harvester  12  are constructed. 
   The center of the lower frame member  20  also serves as the attachment point for the harvester tongue  34  at the tongue pivot mount  40 . The harvester tongue  34  ties the harvester  12  to the towing vehicle and the tongue pivot mount  40  allows it to pivot from side to side in the horizontal axis. This pivoting motion allows the track of the harvester  34  to be adjusted independently from the track of the towing vehicle thus, providing a mechanism to maintain the proper orientation of the harvester  12  relative to the row crop during farming operations. Additionally, the ninety degree angle formed at the junction of the lower frame member  20  and the harvester tongue  12  is spanned at a forty five degree angle by the horizontal adjustment cylinder  36 . The horizontal adjustment cylinder  36  is pivotally mounted on either end to the lower frame member  20  and harvester tongue  34  by the use of a pair of cylinder mounts  38  that extend outward from the surfaces of these two components. The horizontal adjustment cylinder  36  operates through the activation of the harvesters&#39;s  12  hydraulic system (to be discussed in greater detail below) through its expansion and contraction which changes the tracking angle of the harvester  12  relative to the towing vehicle. This allows the operator of the towing vehicle to make adjustments in the track of the harvester  12  to compensate for variances in the track of the towing vehicle and anomalies in the rows of the crop being worked on. 
   The primary frame  14  also serves as the attachment point for the pivot frame  16  which extends rearward from this attachment. The attachment of the pivot frame  16  to the primary frame  14  is accomplished through the use of a plurality of pivot members  28  which extend rearward from the upper frame member  22  to the most forward upper surface of the pivot frame  16 . The pivot members  28  are pivotally mounted on either end to these surfaces by the use of the pivot member mounts  30  which allow them to freely pivot in the vertical plane while providing a secure method of attachment in the horizontal plane. This method of attachment allows the orientation of the pivot frame  16  to be altered in the vertical plane in relation to the orientation of the primary frame  14  which is critical to the operation of the harvester  12  as it allows the digging discs  18  to be engaged and disengaged with the surface of the ground  62  during the operation of the harvester  12 . 
   An additional component tying the pivot frame  16  to the primary frame  14  is the vertical adjustment cylinder  42 . The vertical adjustment cylinder  42  extends in a diagonal orientation from the lower surface of the upper frame member  22  to the upper surface of the pivot frame disc mount frame  26  and is the mechanism of the harvester  12  employed to alter the vertical orientation of the pivot frame  16  to the primary frame  14 . The altering of this relationship is accomplished by the expansion and contraction of the vertical adjustment cylinder  42  (again by the activation of the harvester&#39;s hydraulic system) which increases or decreases the distance between the upper frame member  22  of the primary frame  14  and the pivot frame disc mount frame  26  of the pivot frame  16 . This variance is facilitated by the use of the pivot members  28  discussed above as they provide a mechanism by which the pivot frame  16  can pivot around their connection with the primary frame  14 . 
   The pivoting nature of the pivoting frame  16  is the mechanism which allows the operator to raise and lower the digging discs  18  attached to the lower surface of the pivot frame disc mount frame  26  by the use of the disc mounts  19 . The raising and lowering of the digging discs  18  is pivotal to the operation of the harvester  12  as it allows the operator to engage and disengage the digging discs  18  with the surface of the ground  62  as required by the nature of the operation being performed by the harvester  12 . 
   The body of the harvester  12  is primarily composed of the pivot frame  16  which is a cart like apparatus having vertical pivot frame members  32  at its most forward end connecting it to the pivot members  28  and the pivot frame disc mount frame  26 . The rearward end of the pivot frame  16  is equipped with a pair of harvester wheels  13  which allow the harvester  12  to be towed while providing an accurate tracking mechanism to apply the steering inputs supplied by the horizontal adjustment cylinder  36  as described above. 
   The attachment of the present invention to the harvester  12  is illustrated in  FIGS. 3 ,  4 , and  5  which detail its manner of construction and its relationship to the operational components of the harvester  12 . The present invention is fixedly attached to the upper surface of the pivot frame disc mount frame  26  by the use of the position apparatus mount  44 . The position apparatus mount  44  is a right angled frame member having a U-shaped vertical portion that engages the upper surface of the pivot frame disc mount frame  26  and from which has extending from it in a forward manner a horizontal section which provides the point of attachment for the position frame pivot mount  66 . Additionally, the upper surface of the position apparatus mount  44  has an additional right angled electric actuator mount  64  which extends out and forward. The electric actuator mount  64  serves as the point of attachment for the electric linear actuator  56  which is employed to adjust the relative height of the present invention in relation to the harvester  12  through its attachment to the position frame pivot mount  66 . 
   The position frame pivot mount  66  functions to tie the position apparatus mount  44  to the position apparatus frame  46  and consists of two pivot mount brackets  70 , one of which is attached to the forward surface of the position apparatus mount  44  and the other is attached to the rearward surface of the position apparatus frame  46 . The gap between the pivot mount brackets  70  is spanned by a plurality of pivot mount rails  68  which are rectangular bars each of which is pivotally fixed on either end to opposite pivot mount brackets  70  thus, forming a box-like configuration in which the two pivot mount brackets  70  are capable of moving in a vertical manner with respect to one another. This method of attachment of the position apparatus frame  46  to the position apparatus mount  44  allows the position apparatus frame  46  to be raised and lowered in relation to the body of the harvester  12 . 
   The raising and lowering of the present invention through the position apparatus frame  46  is accomplished through the operation of the electric linear actuator  56 . The electric linear actuator  56  operates in much the same fashion as a hydraulic cylinder except it functions through the use of electricity instead of hydraulic pressure which avoids the pulsating tendencies associated with the use of hydraulics. The expansion of the electric linear actuator  56  forces the position apparatus frame  46  in an outward and downward fashion through its connection with the position frame pivot mount  66 . This motion in turn lowers the present invention into the desired position on the surface of the ground  62  so that it can function to control the orientation of the harvester  12  relative to the primary and pivot frames,  14  and  16 . The present invention is positioned in this ground  62  engaged orientation during field operations to control the vertical and horizontal attitude of the harvester  12 . Conversely, during the transport or storage of the harvester  12 , the flow of hydraulic pressure is reversed thereby lifting the present invention off of the ground  62  through the raising of the position apparatus frame  46 . 
   The position apparatus frame  46  is C-shaped section of tubular frame with the open portion of the C facing towards the body of the harvester  12 . Further, the top portion of the position apparatus frame  46  extends through the gap between the lower and upper frames,  20  and  22 , of the primary frame  14  and the lower end of the position apparatus frame  46  terminates below the lower surface of the lower frame member  20 . Additionally, the lower portion of the position apparatus frame  46  forms the point of attachment for the position apparatus feet  48  which are the components of the present invention used to monitor the relative position of the surface of the ground  62  and which provide the inputs necessary to make the alterations to the orientation of the harvester  12 . 
   The position apparatus feet  48  are attached to the lower surface of the position apparatus frame  46  by the use of the feet mount pin  80  which extends through the body of the position apparatus frame  46  down to its T connection with the feet cross bar  110  (not shown in these FIGURES). At either end of the feet cross bar  110  there is attached a feet ball joint  50  which provides a mounting mechanism for the position apparatus feet  48  that is freely pivotal in all rotational planes. Additionally, each of the two position apparatus feet  48  are independently mounted to the invention through the use of the feet ball joints  50  which means that they are both fully and independently pivotal. 
   The position apparatus feet  48  are connected to a vertical sensing valve  52  and a horizontal sensing valve  54  through the vertical linkage assembly  58  and the horizontal linkage assembly  60  respectively. The vertical linkage assembly  58  transfers vertical inputs from the position apparatus feet  48  to the vertical sensing valve  52  which imparts correcting impulses to the harvester through the hydraulic system (to be discussed in detail below). The vertical linkage assembly  58  is made up of two identical vertical pivot bracket  78  which are mounted on opposite sides of the lower end of the position apparatus frame  46  in their centers by the use of the pivot pins  79 . The vertical pivot brackets  78  are relatively short sections of flat metal having an angled lower section that is offset by forty five degrees in a rearward manner from the longitudinal axis of the vertical pivot brackets  78 . The upper ends of the vertical pivot brackets  78  are pivotally attached to the outer ends of the vertical linkage T-rod  83  which spans the space between the upper ends of the vertical pivot brackets  78  above the upper surface of the position apparatus frame  46 . The vertical linkage T-rod  83  is in turn connected at its center to the forward end of the vertical actuator valve rod  84  which engages the vertical sensing valve  52  at its rearward end. Finally, the lower ends of the vertical pivot brackets  78  are pivotally attached to the upper ends of the vertical linkages  82  which are in turn attached at their lower ends to the position apparatus feet  48 . Thus, when the position apparatus feet  48  are forced upwards or downwards, the vertical pivot brackets  78  rotate around the pivot pins  79  forcing the vertical linkage T-rod  83  to move forward or rearward which is transferred to the vertical sensing valve  52  through the vertical actuator valve rod  84 . 
   The horizontal linkage assembly  60  transfers horizontal inputs from the position apparatus feet  48  to the horizontal sensing valve  54  which imparts correcting impulses to the harvester through the hydraulic system to be discussed in detail below. The horizontal linkage assembly  60  is made up of the horizontal valve actuator rod  104  which is pivotally connected at its forward end to the upper surface of the feet cross bar  110  and at its rearward end to the horizontal sensing valve  54 . Thus, any change in horizontal attitude of the position apparatus feet  48  is transferred to the horizontal sensing valve  54  through the horizontal valve actuator rod  104 . 
   The positional inputs of the position apparatus feet  48  are transferred to the harvester&#39;s  12  horizontal adjustment cylinder  36  and vertical adjustment cylinder  42  through the present invention&#39;s hydraulic system. The hydraulic pressure necessary to operate these components of the invention is supplied from a connection with the towing vehicle&#39;s hydraulic system through a connection at the main pressure port  98  located on the pressure manifold  96  which is in turn connected to the horizontal sensing valve  54 . The pressure manifold  96  operates to divide the flow of hydraulic pressure into two separate systems. The first of these provides hydraulic pressure to the horizontal sensing valve  54  and its related components which is initially facilitated by the connection between the two. The hydraulic pressure contained within the horizontal sensing valve  54  can then be diverted to the harvester&#39;s  12  horizontal adjustment cylinder  36  by the action described above through the cylinder pressure hose  72  which runs from the upper surface of the horizontal sensing valve  54  to the horizontal adjustment cylinder  36 . Additionally, a cylinder return line  74  runs from the opposite end of the horizontal adjustment cylinder  36  to the horizontal sensing valve  54  to complete the system. The hydraulic pressure is returned to the towing vehicle by means of the horizontal valve return hose  86  which connects to the return manifold  76  located on the other side of the invention. Finally, the connection between the horizontal sensing valve  54  and the horizontal valve return hose  86  contains a one-way valve that will not allow the hydraulic pressure to back flow into the horizontal sensing valve  54  during its operation. 
   The second hydraulic system contained within the present invention supplies the vertical sensing valve  52  which is connected to the pressure manifold  96  through the vertical valve pressure hose  102 . The hydraulic pressure contained within the vertical sensing valve  52  can then be diverted to the harvester&#39;s  12  vertical adjustment cylinder  42  by the action described above first through the vertical adjustment cylinder pressure hose  90  which runs to the forward end of the pressure manifold  96 . From this point, the hydraulic pressure exits the lift cylinder pressure port  100  which has connected to it a cylinder pressure hose  72  which in turn supplies the vertical adjustment cylinder  42  with hydraulic pressure. Additionally, a cylinder return hose  74  runs from the opposite end of the vertical adjustment cylinder  42  to the vertical adjustment cylinder return port  92  located on the return manifold  76  to complete this portion of this system. The hydraulic pressure is then returned to the towing vehicle through the main return port  94  located on the return manifold  94 . 
   The manner of construction of the position apparatus feet  48  is further detailed in  FIGS. 6 and 7  which illustrate their ability to adjust to row crops of varying sizes without affecting the performance of the present invention. The use of the feet ball joints  50  to connect the position apparatus feet  48  to the feet cross bar  110  allows each of them to move independently from one another. In order to tie their motion more closely together, the invention employs a pair of open springs  106  attached to their rearward most ends and a centrally located open spring tab  108  that place a opening force on the forward points of the position apparatus feet  48 . Additionally, the inner area of the position apparatus feet  48  at their midway point at a pair of inwardly extending spring brackets  114  are equipped with a pair of close springs  112  which place a closing force on them. These forces act to maintain the position apparatus feet  48  in a neutral position unless an object is encountered that tends to force them open. 
   The operation of the horizontal sensing valve  54  is further detailed in  FIGS. 8 and 9  which illustrate the manner in which horizontal variations in a row crop are sensed by the position apparatus feet  48 .  FIG. 8  illustrates the orientation of the position apparatus feet  48  in the neutral position. Conversely,  FIG. 9  illustrates the orientation of the position apparatus feet  48  when a force has deviated them in one direction or the other. The deviation of the position apparatus feet  48  is transferred to the feet cross bar  110  which in turn changes the lateral orientation of the connected horizontal valve actuator rod  104 . The change in the orientation of the horizontal valve actuator rod  104  activates the horizontal sensing valve  54  which in turn makes the appropriate adjustments in the hydraulic system to return the harvester  12  to the proper orientation with respect to row crop. Once these adjustments have been accomplished, the position apparatus feet  48  return to their neutral position and the inputs of the horizontal sensing valve  54  are ceased. 
   The operation of the vertical sensing valve  52  is further detailed in  FIGS. 10 and 11  which illustrate the manner in which horizontal deviations in the surface of the ground  62  are sensed and transferred to the appropriate components of the present invention.  FIG. 10  illustrates the position of the position apparatus feet  48  when they are in their neutral orientation in respect to the vertical plane. Conversely,  FIG. 11  illustrates the orientation of the pertinent components of the invention when an irregularity  61  is encountered by the position apparatus feet  48 . The change in attitude in the position apparatus feet  48  caused by the irregularity  61  is transferred to the vertical sensing valve  52  through the vertical linkage assembly  58  as described above. This engages the vertical sensing valve  52  which in turn activates the hydraulic system to make appropriate height adjustments in the attitude of the harvester  12  to bring the position apparatus feet  48  back to their neutral position. 
   Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.