Abstract:
An automatic net and tube feeding system for a sod harvester having a conveyor upon which rolls of sod are formed includes a net feeder comprising a supply roll from which net is dispensed, a pair of feed rollers positioned to engage a portion of the net therebetween and a motor selectively operable to turn one of the feed rollers to eject a length of net onto the conveyor. Also included in the system is a net cutter having a cutting blade pivotally mounted parallel to the feed rollers and a stop bar for locking the supply roll. The system further includes a tube feeder for dispensing core tubes around which the sod rolls are formed, the tube feeder comprising a rack having a discharge opening and a tube dispenser selectively controlling the release of individual core tubes through the discharge opening and onto the conveyor.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to large roll sod harvesters, and in particular to a net and core tube feeding system for use on such sod harvesters. 
   2. Description of the Related Art 
   U.S. Pat. No. Re. 34,827, entitled “Method and Apparatus for Cutting Sod Which Rolls in a Semi-flaccid Sheet into Sod Roll,” and commonly owned with the present invention, discloses a large roll sod harvester wherein sod is carried onto a roll-forming conveyor on a layer of net. The conveyor rolls the sod and net into a sod roll which is formed around a core tube or mandrel which then comprises the core of the sod roll. As the roll is formed, the net is pulled from a supply roll mounted below the roll-forming conveyor. 
   In the disclosed embodiment, a length of the net must be manually pulled off of the supply roll and started onto the conveyor by hand before the sod cutting operation begins. The core tube is also manually placed on the conveyor and retained in position by a rod manually inserted through the center of the core tube. The sod is then manually bent around the core tube to start the roll. After the roll is completed, the net must also be manually cut loose from the supply roll and the process repeated before another roll can be started. 
   As is apparent from the above description, this original embodiment of the sod harvester required a great deal of manual intervention to form a roll of sod. In order to eliminate this need for human involvement, what is needed is an automatic system for starting and cutting the net, and also for placing the core tubes on the roll-forming conveyor. 
   SUMMARY OF THE INVENTION 
   The present invention is an automatic net and core tube feeding system for a sod harvester. The system includes a net feeder and a tube feeder which act in combination to supply net and core tubes to a roll forming conveyor where sod is formed into rolls. The system also includes a net cutter which cuts the net loose from the net feeder once the roll has reached its ultimate size. 
   The net feeder generally comprises a supply roll from which net is dispensed, a pair of feed rollers positioned to engage a portion of the net therebetween, and a motor selectively operable to turn one of the feed rollers to eject a length of net onto the conveyor. The net cutter includes a cutting blade mounted parallel to the feed rollers which is pivotable between a retracted position and a cutting position wherein the blade engages the net. The net cutter also includes a stop bar which is engageable with a radially extending tooth on the supply roll for locking the supply roll while the a cut is made. 
   The tube feeder includes a rack mounted above the conveyor and sized to hold a plurality of core tubes. The rack has a discharge opening and a tube dispenser selectively controlling the release of individual ones of the core tubes through the discharge opening and onto the conveyor. The rack preferable includes a removable rack portion which can be lifted off of the sod harvester with a fork lift and refilled with core tubes at ground level. The tube dispenser generally includes a pivot shaft rotatably mounted below the discharge opening, a plurality of distributing plates longitudinally spaced along the pivot shaft and an actuator connected to said pivot shaft and adapted to rotate said pivot shaft between a home position and a drop position. 
   Each of the distributing plates includes a finger extending radially outwardly from the pivot shaft and a heel having a top edge generally perpendicular to the finger, a bottom edge extending generally opposite the finger and a back edge forming an arcuate bumper extending between the top edge and the bottom edge. When the pivot shaft is in the home position, the fingers extend across the discharge opening and prevent any of the core tubes from passing therethrough. As the pivot shaft moves toward the drop position, one of the core tubes is lifted into a tube cradle formed between the fingers and the top edges of the distributing plates. Simultaneously, the bumper prevents any of the remaining core tubes from advancing toward the discharge opening. When the pivot shaft reaches its drop position, the core tube rolls out of the tube cradle, down the fingers, and drops onto the roll-forming conveyor. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1 . is a fragmentary, partially schematic side view of a sod harvester incorporating an automatic net and core tube feeding system according to the present invention. 
       FIG. 2  is a perspective view of the sod harvester of  FIG. 1  as seen from a position just behind the front conveyor thereof. 
       FIG. 2   a  is a partially schematic representation of a drive motor of a net feeder which forms a part of the present invention. 
       FIG. 3  is a fragmentary perspective view of the net feeder. 
       FIGS. 4   a – 4   c  are fragmentary perspective views of a core tube feeder which forms a part of the present invention. 
       FIGS. 5   a – 5   c  are schematic views showing operation of the tube feeder. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof. 
   Certain terminology will be used in the following description for convenience in reference only and will not be limiting. For example, the words “upwardly,” “downwardly,” “rightwardly,” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the embodiment being described and designated parts thereof. Said terminology will include the words specifically mentioned, derivatives thereof and words of a similar import. 
   Referring to the drawings in more detail, and in particular to  FIG. 1 , the reference number  1  generally designates a large roll sod harvester incorporating features according to the present invention. The harvester  1  includes a frame  3  and a pair of cutting heads  5  mounted on the frame  3  which cut sod loose from the ground. The cutting heads  5  are mounted generally as shown in U.S. Pat. Re 34,827, which is commonly owned with the present invention. A front conveyor  7  carries the sod rearwardly and upwardly from the cutting heads  5 . The front conveyor  7  has an exit end  9 . 
   The front conveyor  7  delivers the sod to a generally L-shaped rear conveyor  11  having a feed leg  13  and a roll-forming leg  15 . The feed leg  13  of the rear conveyor  11  has an entrance end  17 . Rolls of sod are formed on the rear conveyor  11  between the legs  13  and  15 . The sod is carried on net or mesh  19  which is fed into the rolls along with the sod by a net feeder  21 . Each roll of sod is formed around a core tube  23  which is dispensed onto the rear conveyor  11  by a tube feeder  25 . 
   The rear conveyor  11  is pivotally mounted to the frame  3  for movement about a generally horizontal transverse axis  27  and is selectively moveable about the axis  27  by linear actuators  29  which are operatively connected to a hydraulic system of the harvester  1 . The rear conveyor  11  has four operating positions: a feed position A wherein the entrance end  17  of the feed leg  13  is in general horizontal alignment with the exit end  9  of the front conveyor  7 , a net starting position B wherein the entrance end  17  of the feed leg  13  is dropped below the exit end  9  of the front conveyor  7 , a net cutting position C wherein the entrance end  17  of the feed leg  13  is raised above the exit end  9  of the front conveyor  7 , and a dump position D wherein the rear conveyor  11  is tipped over rearwardly such that the feed leg  13  is raised into a generally vertical or past vertical orientation. 
   Referring to  FIG. 2 , the net feeder  21  is generally located beneath the exit end  9  of the front conveyor  7  and includes a transverse supply roll  33  from which the net  19  is dispensed. Mounted above the supply roll  33  are first and second transverse feed rollers  35  and  37 , respectively, between which the net  19  passes. The first feed roller  35  is rotatably mounted to the frame  3  in a fixed position and selectively driven by a hydraulic motor  39  acting through a chain  40  and sprag clutch or one-way bearing  41  (see  FIG. 2   a ). The second feed roller  37  is rotatably and moveably mounted to the frame  3  for movement toward and away from the first feed roller  35 . An over-center latch mechanism  42  allows the second feed roller  37  to be drawn toward and clamped against the first feed roller  35 , capturing the net  19  therebetween. 
   The hydraulic motor  39  driving the first feed roller  35  is controlled by a valve  43  which is mounted on the frame  3 . The valve  43  has a plunger  45  which is engaged and depressed by the feed leg  13  of the rear conveyor  11  when the rear conveyor  11  moves into its net feeding position. When the plunger  45  is depressed, the motor  39  is engaged, rotating the feed rollers  35  and  37 . Rotation of the feed rollers  35  and  37  causes a length of the net  19  to be pulled off the supply roll  33  and ejected onto the feed leg  13  of the rear conveyor  11 . The motor  39  stops when the rear conveyor  11  is moved out of its net feeding position and back into its feed position, thereby releasing the plunger  45 . The rear conveyor  11  preferably remains in the net feeding position long enough for approximately one foot of the net  19  to be dispensed. 
   Pivotally mounted to the frame  3  above the feed rollers  35  and  37  is a net cutoff knife  47 . The knife  47  comprises a knife shaft  49  and a blade  51  which is secured to the shaft  49  and extends tangentially outward therefrom. The blade  51  includes an sharpened distal edge  53 . The knife  47  is pivotable between a retracted position wherein the edge  53  is angled rearwardly away from the net  19  and a cutting position wherein the edge  53  is brought into engagement with the net  19 . 
   Referring to  FIG. 3 , movement of the knife  47  is controlled by a lever arm  55  which extends radially outward from the shaft  49  and rearwardly therefrom. The knife  47  is urged into the cutting position by an extension spring  57  connected between the frame  3  and a lug  59  on the lever arm  55 . A roller  61  mounted proximate the distal end of the arm  55  is engageable by the feed leg  13  of the rear conveyor  11 . When the rear conveyor  11  is in its feed position or net starting position, the feed leg  13  acts downwardly on the lever arm  55  and counters the action of the spring  57  to move the knife  47  into its retracted position (see  FIG. 3 ). When the rear conveyor  11  moves upwardly into its net cutting position, pressure on the lever arm  55  is relaxed and the spring  57  acts to move the knife  47  into its cutting position (see  FIG. 2 ). 
   Connected to the lower edge of the lever arm  55  is an arcuate member  63  having a cam surface  65  formed by its lower edge. A stop bar  67  is pivotally connected to the frame  3  above the supply roll  33  and below the feed rollers  35  and  37 . The stop bar  67  has opposed first and second ends  69  and  71 , respectively. Selectively slidably mounted to the first end  69  of the stop bar  67  is an adjustable carrier  73  which carries a roller follower  75 . The roller follower  75  rollingly engages the cam surface  65  of the arcuate member  63 . The second end  71  of the stop bar  67  includes a pawl  77  which is engageable with a ratchet  79  on the supply roll  33  having radially extending teeth or fins  80 . The stop bar  67  is balanced such that the second end  71  is urged downwardly by its own weight. As the rear conveyor  11  moves between its various positions, the lever arm  55  also moves, causing the roller follower  75  to move along the cam surface  65  of the arcuate member  63 . 
   The arcuate member  63  is shaped such that the ratchet pawl  77  is held upwardly, away from the ratchet  79 , when the rear conveyor  11  is in its feed position or net starting position (see  FIG. 3 ), but as the rear conveyor  11  moves upwardly into its net cutting position, the first end  69  of the stop bar  67  pivots downwardly until the pawl  77  engages one of the teeth  80  and thereby locks the supply roll  33  (see  FIG. 2 ). As will be explained in more detail later, this causes the net  19  to be pulled tightly against the sharpened edge  53  of the knife  47 , cutting the net  19 . 
   Referring again to  FIG. 2 , a net splitter  81  mounted below the feed rollers  35  and  37  includes a transverse net splitter shaft  83  pivotally mounted to the frame  3  and a blade  85  which extends perpendicularly outward from the shaft  83  proximate a midline of the conveyors  7  and  11 . The shaft  83  is pivotable between a cutting position wherein the blade  85  is in engagement with the net  19  and a retracted position wherein the blade  85  is clear of the net  19 . The shaft  83  is selectively pivoted by a linear actuator  87  mounted between the frame  3  and a lever arm  89  extending radially outwardly from the shaft  83  proximate one end thereof. The net splitter  81  allows the operator to selectively form two half-width rolls of sod instead of a single full-width roll by splitting the net  19  in two. Pairs of half-length core tubes (not shown) are used in place of the full length tubes  23  when half-width rolls are desired. The sod itself does not need to be split since each of the cutting heads  5  naturally produces a respective strip of sod and only the net  19  and tube  23  normally hold the two strips together to form a single full-width roll. 
   Referring to  FIG. 4 , the tube feeder  25  is mounted above the front conveyor  7  and includes a removable rack  91  and a fixed rack  93 . Both racks  91  and  93  may be constructed of square steel tubing. The fixed rack  93  has a forward compartment  95  and a rearward compartment  97 . The removable rack  91  generally comprises a box sized to hold a plurality of core tubes  23 , for example sixty tubes  23 . The forward compartment  95  of the fixed rack  93  is sized to receive the removable rack  91  and serves as a docking station for the removable rack  91 . The forward compartment  95  includes a side gate  99  through which the removable rack  91  can be removed and inserted using a forklift (not shown). The removable nature of the rack  91  allows it to be lowered to ground level for ease of loading with core tubes  23 . Once loaded, the removable rack  91  is then lifted by the forklift and reinserted into the forward compartment  97  through the side gate  99 . The side gate  99  is then closed to retain the removable rack  91 . 
   The forward and rearward compartments  95  and  97  of the fixed rack  93  share a floor  101  which slopes downwardly from front to rear. The removable rack  71  includes a rearward wall  103  having a discharge opening  105  positioned at its lower end. An upwardly pivotable tailgate  107  selectively covers the discharge opening  105 . The discharge opening  105  is sized such that, when the tailgate  107  is open, a single layer of the core tubes  23  will roll through the discharge opening  105  and into the rearward compartment  97 . 
   The rearward compartment  97  of the fixed rack  93  includes a rear wall  109  having an opening  111  equipped with a tube dispenser  113  designed to drop individual ones of the core tubes  23  onto the rear conveyor  11  at the proper intervals. The dispenser  113  includes a transverse pivot shaft  115  rotatably mounted to the fixed rack  93  below the opening  111 . A lever arm  117  is connected to the pivot shaft  115  proximate one of its ends and extends radially outwardly therefrom. A linear actuator  119 , such as a double acting hydraulic cylinder, is connected between lever arm  117  and a lug  121  extending outwardly from the fixed rack  93 . The actuator  119  is operable to rotate the pivot shaft  115  between a home position and a tube drop position. 
   Laterally spaced along the pivot shaft  115  are a plurality of distributing plates  123 . Each distributing plate  123  includes a finger  125  which extends generally radially outward from the pivot shaft  115  and a heel  127 . The heel  127  of each distributing plate  123  includes a bottom bar  129  which extends opposite the respective finger  125  and a top bar  131  which is generally perpendicular to the respective finger  125 . The bottom bar  129  and top bar  131  of each heel  127  are connected by an arcuate bumper  133 . A tube cradle  135  is defined by the fingers  125  and top bars  131  of the distributing plates  123 . Interposed between the distributing plates  123  are respective short arms  137  which are generally in alignment with the fingers  125 . 
   Referring to  FIG. 5   a , when the pivot shaft  115  is in the home position the fingers  125  are pointed upwardly and the top bars  131  of the heels  127  are positioned below the floor  101 . Due to the slope of the floor  101 , any core tubes  23  located in the rearward compartment  97  of the fixed rack  93  will roll rearwardly until a rearwardmost core tube  23   a  of the core tubes  23  is abutted against the fingers  125 . When the actuator  119  begins to extend, as in  FIG. 5   b , the fingers  125  will begin to move downwardly and the top bars  131  will begin to move upwardly, thereby urging the rearwardmost core tube  23   a  into the tube cradle  135 . Simultaneously, the bumper  133  will engage a second most rearward core tube  23   b  of the core tubes  23  and prevent it from rolling rearwardly. Referring to  FIG. 5   c , when the pivot shaft  115  reaches the tube drop position, the fingers  125  become downwardly and rearwardly sloped such that the core tube  23   a  will roll out of the tube cradle  135  and down the fingers  125  until it drops off the ends fingers  125  and onto the rear conveyor  11 . The pivot shaft  115  is then returned to the home position by retraction of the actuator  119 . Once the top bars  131  drop below the floor  101  the core tube  23   b  will roll up against the fingers  125  and will remain there until such time as the process is repeated. 
   In order to start a roll of sod, the rear conveyor  11  is pivoted downwardly into its net starting position. The feed leg  13  contacts the plunger  45 , opening the valve  43  and causing the motor  39  to turn the first feed roller  35  and thereby advance approximately one foot of net  19  onto the feed leg  13  of the rear conveyor  11 . Simultaneously, the rear conveyor  11  is started so that the net  19  is drawn flat onto the conveyor  11 . The rear conveyor  11  then stops and tips upwardly into the feed position, releasing the plunger  45  and closing the valve  43  such that rotation of the motor  39  ceases. 
   When the rear conveyor  11  reaches the feed position a conveyor position sensor (not shown) sends a signal to a controller (not shown), causing the controller to extend the actuator  119  on the tube dispenser  113  to pivot the fingers  125  downwardly, thereby dropping a core tube  23  onto the feed leg  13 . After the core tube  23  drops and the pivot shaft  115  reaches its drop position and, a pivot shaft sensor (not shown) sends a signal to the controller which then retracts the actuator  119 , moving the pivot shaft  115  back into the home position and the fingers  125  into an upward orientation. 
   At this point in the cycle, both the front conveyor  7  and rear conveyor  11  are started and the harvester  1  is advanced to cut a strip of sod. The sod comes off the front conveyor  7  and onto the rear conveyor  11  on top of the net  19 . The net  19  and sod are both advanced by the action of the feed leg  13  of the rear conveyor  11 . The sprag clutch  41  allows the feed rollers  35  and  37  to freewheel as the net  19  is pulled through them, without resistance from the then inactive motor  39 . The roll forming leg  15  turns the sod and net  19  upwardly such that they both wrap around the core tube  23  to form a roll. The sod continues to feed onto the rear conveyor  11  and into the roll until a predetermined length of sod is accumulated and a cut end of the sod reaches the exit end  9  of the front conveyor  7 . (The sod is cut by a sod cutting mechanism which is not part of the present invention.) At this time, forward progress of the harvester  1  is halted and both the front conveyor  7  and rear conveyor  11  are stopped. 
   In order to wrap the sod roll in net  19 , the rear conveyor  11  only is restarted, for 1–2 revolutions rotating the sod roll  11  and pulling additional net onto the sod roll. The rear conveyor then stops and is pivoted upwardly into its net cutting position. As this happens, the knife  47  pivots into its cutting position and the ratchet pawl  77  engages one of the teeth  80  of the ratchet  79  to stop rotation of the net supply roll  33 . With the supply roll  33  locked and the feed leg  13  of the rear conveyor  11  tipping upwardly, the net  19  is pulled tightly across the cutting edge  53  of the knife  47  and thereby severed. The rear conveyor is then restarted briefly to wrap the loose end of the net  19  onto the sod roll. When the sod roll is completely wrapped, the rear conveyor  11  stops and is then pivoted upwardly into the dumping position, causing the sod roll to be deposited over the end of the roll forming leg  15  and to the rear of the harvester  1 . In order to move the sod roll out of the way of the next pass of the harvester  1 , a cart (not shown) having a turntable thereon may be hitched behind the harvester  1  to catch the sod rolls as they come off of the rear conveyor  11  and turn them ninety degrees about a vertical axis. The sod rolls can then be dumped off the outboard side the cart such that they roll away from the remaining uncut sod. 
   Once the sod roll is dumped, the rear conveyor moves back into its net starting position and the process is repeated for the next sod roll. All of the movements of the rear conveyor  11  and other components of the harvester  1  may be automatically controlled such that the cutting and baling process takes place with minimal input from the operator. 
   It is to be understood that while certain forms of the present invention have been illustrated and described herein, it is not to be limited to the specific forms or arrangement of parts described and shown.