Abstract:
Disclosed is an automatic pallet presenter for agricultural equipment. The pallet presenter has a storage magazine for storing pallets and a rotatable table mechanism for bringing pallets into a desired location.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to an automatic pallet dispensing mechanism, and more particularly to an automatic pallet dispensing mechanism for agricultural equipment.  
       BACKGROUND OF THE INVENTION  
       [0002]     For a number of years there has been an awareness of a need for automatic stacking of agricultural products at the point of collection, or harvesting. The automatic stacking of the products allow for a single equipment operator to easily harvest a large volume of produce. These harvested stacked products must be of course transported from the field in a form which allows easy transportation to distributors and end consumers. Palletized skids are therefore often used for truck transport of these agricultural products from the field to centralized distribution points.  
         [0003]     The automated agricultural operations require the continuous packaging of a large number of such produce during any particular work shift. As such, typical agricultural operations require movement, positioning and temporary storage of large numbers of such stackable pallets at the harvesting location. Substantial distances causes problems for the movement and repositioning of both full and empty pallets or containers. Typically, empty storage pallets are moved by the farm worker into scattered positions about the harvesting locations where they can be filled either by hand or automated equipment. Due to the size and weight of these empty storage containers, significant ergonomic problems have arisen. Auto loading pallets eliminates the loss productivity and operator annoyance associated with getting out of the tractor cab each time a fresh pallet is required. Auto-stacking sod harvesters have been on the market for some time. One presently available commercial machine utilizes a stack of pallets located behind the area where the sod is loaded onto the pallet. When the pallet is full it is dropped to the ground and the sod harvesting machine pulls ahead leaving the filled pallet behind. When the machine has moved far enough ahead, a pallet dispenser pushes the bottom pallet from a stack of pallets onto the forks of the machine and another pallet proceeds to be loaded with rolls of sod.  
         [0004]     There are several disadvantages to this method. The stack of pallets needs to be stored high enough in the air over the vehicle to clear a full pallet of sod, thus causing a high machine center of gravity. Further, the height makes it difficult to reach the pallet dispenser if it is necessary to hand load pallets into the dispenser. The height also means the vehicle&#39;s forks must be configured to regularly raise beyond where they would be for normal loading to accept an empty pallet, thus requiring the operator to stop harvesting operations while the pallet loads. This disrupts productivity. Additionally, having the dispenser behind the sod loading area contributes at least the length of the pallet to the overall length of the machine, making it less stable and maneuverable. These less maneuverable machines are harder to operate, particularly in smaller sod fields where more turnarounds are required to harvest a given area of sod. Furthermore, a long machine may require outrigger wheels to hold up the extended mechanism. Such wheels require spring loading of the wheel or hinging of the machine to allow travel over undulations and contribute extra complexity.  
         [0005]     It is, therefore, desirable to provide an agricultural product container storage and delivery system which facilitates the delivery of fresh pallets or empty containers to an agricultural field as needed. It is also desirable to provide such a system which enables empty pallets or containers to be similarly transported to a desired location without operator or continuous service vehicle assistance. It is further desirable to provide such a system which stores empty agricultural produce containers as desired and which facilitates the storage, delivery, positioning and removal of a sufficient number of such containers to obviate the need for supplemental vehicle intervention over the entire work shift. It is also desirable to provide a system which enables agricultural workers to place containers within harvesting equipment as needed.  
       SUMMARY OF THE INVENTION  
       [0006]     It is the object of the present invention to overcome the disadvantages of a rear mounted pallet dispenser as detailed above. Disclosed is an agricultural harvester with a pallet delivering system mounted to the side of the sod harvesting machine. The pallet delivery system is positioned opposite the sod cutting and handling equipment, and fully mounted on the machine. A stack of pallets is loaded into the magazine and are supported by a first set of rotatable flanges affixed on opposite sides of the magazine. Below the magazine is a pallet carrying table which is configured to be rotatable in a horizontal plane with a second set of rotatable flanges configured to drop the pallet into a loading location.  
         [0007]     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:  
         [0009]      FIG. 1  represents a side view of the agricultural equipment having a pallet storage container according to the teachings of the present invention;  
         [0010]      FIG. 2  represents a left rear perspective view of a sod harvester utilizing a pallet presenter according to the teachings of the present invention;  
         [0011]      FIGS. 3 and 4  represent side and right front views of the sod harvester shown in  FIG. 2 ;  
         [0012]      FIGS. 5-7  represent top, rear and bottom views of the sod harvester shown in  FIG. 2 ;  
         [0013]      FIGS. 8 and 9  represent right rear perspective and left views of the sod harvester shown in  FIG. 2 ;  
         [0014]      FIG. 10  represents a sod harvester shown in  FIG. 2  with a pallet presenter shown in its actuated position;  
         [0015]      FIG. 11  represents a sod presenter shown in  FIG. 2  with the pallet presenter shown in its fully actuated position;  
         [0016]      FIG. 12  represents a sod presenter shown in  FIG. 2  with the pallet storage mechanism in its stored transportation position;  
         [0017]      FIGS. 13-15  represent the indexing of a pallet stack; and  
         [0018]      FIGS. 17 and 18  represent the actuation of the table mechanism. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]     The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.  FIG. 1  is an overall isometric view of an agricultural harvester  20  having a harvesting mechanism  21  to harvest a crop, a transportation mechanism  22  configured to transport the crop to a first storage location  24 , a pallet storage container  26 , and a rotatable table mechanism  28  configured to move a pallet from the pallet storage container  26  to the first location  24 . The agricultural harvester  20  further has a wheeled chassis  30  for translating a sod field, and an operator occupied cab.  
         [0020]     The transportation mechanism  22  can take the form of a robot with an articulated arm  25  and a pick-up head  27 . In the context of the invention, a robot is defined as being a digitally controlled arm. Colloquially, a machine may be called a robot even if a human operator is controlling portions of its operations remotely. Reference numeral  34  designates a conveyor which delivers rolled sod to the rear of the sod harvester. The rolled sods are deposited from conveyor  34  onto an indexable accumulator conveyor  40 . Accumulator conveyor  40 , which is made of rubber having indexing lugs, advances every time a sod roll is moved onto it, until a sub-group of sod rolls is accumulated. At this time, a computer (not shown) controls the articulated arm  22  with pick-up head to pick up the sub-group of sod rolls and place them into a piling cavity  42 . In this regard, the piling cavity  42  has a pair of actuate forks, which support a sod supporting skid, or a skidless sod stack.  
         [0021]     The articulated arm is mounted on a base  44  for turning about a vertical axis X-X. One end of a first arm segment  46  is pivotally mounted to base  44  for turning about vertical axis X-X, and one end of a second arm segment  48  is pivotally mounted to the other end of segment  46  about a horizontal axis. A pick-up head  27  is mounted to the other end of segment  48  to turn about a vertical axis. Hydraulic cylinders drive all four of these pivoting actions. Electronic feedback tells the computer the exact location of each cylinder. The computer controls both the position and the speed of each cylinder. The computer can be programmed in a way to optimize the travel time of the pick-up head for maximum productivity.  
         [0022]     Further, the location of the arm is controlled by the computer using pressure transducer or encoder information from the gripping forks. The information is used to sense when the rolls are starting to land on the forks or on the previous row. This feature allows the robot to compensate the position of the rolls of varying diameter, which results in layers of different thickness. By sensing a reduction in pressure when the sod starts to land on the stack reduces cycle time.  
         [0023]     With general reference to  FIGS. 1-7 , shown is a sod harvester utilizing a pallet presenter according to the teachings of the present invention. The harvester  100  has a movable chassis  102  and a cabin portion  101 . Disposed on the first side  103  of the harvester  100  is a harvesting mechanism  104  which is shown as a horizontal sod cutter mechanism  106 . Disposed generally behind and on a second side  108  of the harvester is the pallet presenter mechanism  110 . For clarity, the robotic mechanism previously disclosed which moves the rolls of sod from the harvesting mechanism  104  to the pallet has been removed. While it is envisioned that the system is operable with a robot having an articulating arm, it. is equally possible to utilize the system utilizing an X-Y-Z fixed frame transport mechanism.  
         [0024]     The presentation mechanism  110  has a pallet magazine  112  which is configured to hold a plurality of empty agricultural storage containers. Shown, the magazine  112  is configured to hold a number or stack of empty pallets. When the pallet presentation mechanism  110  is located in its harvesting position  114 , three walls  116  form the pallet magazine  112 . An open side  118  forms an area which is used to load empty pallets into the magazine  112 . Located within the pallet magazine are a set of rotatable flanges  115  which are configured to support and lift the stack of pallets. The empty pallets can be loaded using either a standard fork lift or by hand.  
         [0025]     Disposed on the bottom pallet magazine  112  is a rotatable table mechanism  120  which is configured to remove pallets from the magazine  112  and move them to a first loading location  122 . As described below, the first loading location  122  is a position adjacent the table mechanism  120  where a pair of fork lift type forks are positioned. The first loading location  122  is at or is near where the forks are rotated to allow the disengagement of a filled pallet from the agricultural equipment.  
         [0026]     As best seen in  FIGS. 3 and 5 , the pallet magazine  112  has a top surface  124  which is positioned lower than the tallest position  126  of the cabin  101 . This position lowers the overall center of gravity of the system and reduces the likelihood of inadvertent tipping of the equipment. Additionally as best seen in  FIGS. 3 and 5 , the pallet magazine  112  is stored behind the wheels  132  of the chassis  122 .  
         [0027]      FIGS. 8 and 9  represent right rear perspective and left views of the sod harvester shown in  FIG. 2 . Shown is the harvesting mechanism  104  which is described in co-pending patent application Ser. No. 10/624,462 entitled Robotic Sod Stacker, filed on Jul. 22, 2003, which is herein incorporated by reference. Generally shown is an accumulator mechanism  136  which is indexed and collects rolled sod from a sod cutter (not shown). Generally, the weight and position of this mechanism offsets the weight of the pallet magazine.  
         [0028]      FIG. 10  is a rear perspective view of the sod harvester shown in  FIG. 2  with the pallet presenter shown in its semi-actuated position. As can be seen, the rotatable table mechanism  120  carries an empty skid onto the forks  140 . The table mechanism  120  is rotated about a pivot point in a manner to allow the positioning of the skid in the proper orientation with respect to the forks  140 . Integral to the table mechanism  120  is a pair of releasable rotatable flanges  142  which are used to suspend the empty pallet while the pallet is being moved from the magazine  112  to the first loading location  122 .  
         [0029]     As best seen in  FIG. 11 , the table mechanism  120  is configured to rotate about the pivot point to position the skid onto the forks  140 . Upon releasing the skid onto the forks  140 , the table mechanism  120  is configured to rotate back beneath the pallet magazine  112  and to receive another empty pallet. At this point, the system is configured to lift the pallet using the forks to its proper location for loading of the rolls of sod.  
         [0030]     The pivot axis  152  of the rotary table mechanism  120  is located such that the pallet is centered over the pallet forks when the table mechanism  120  is rotated over the pallet forks and has the front of the pallet toward the front of the forks. When rotated under the pallet magazine  112 , the side  130  of the table mechanism  120  toward the forks is located such that it, along with the magazine  112 , forms a wall defining the space within which a pallet of sod is to be loaded.  
         [0031]     The entire pallet dispensing mechanism  116  is rotatable to a working position and to a transport position. In the transport position, the entire pallet dispensing mechanism is rotated substantially within the overall width of the rest of the sod harvesting machine to reduce the width to allow for easier transport on roads, through gates and over bridges and the like than if it were fixed in place.  
         [0032]      FIG. 12  represents a view of the pallet dispenser in a narrowed transport position. The entire sod presenter mechanism  110  including the pallet magazine  112  and rotatable mechanism  120  is rotated about a pivot line  152  to bring the presentation mechanism  110  between the wheels of the associated chassis  102 .  
         [0033]     The pallet dispensing mechanism is controlled by the sod harvesting machine such that when activated it goes through its cycle automatically without requiring an operator to direct each step.  
         [0034]     In practice, as best seen in  FIGS. 13-16 , a stack of pallets is loaded into the pallet magazine  112  either as a stack with a fork truck or individually, one at a time, by hand. The pallets rest on the second set of releasable flanges  115  connected to a pair of shafts in the magazine  112 . The first pair of shafts are rotated to open the tray formed by the second set of flanges  115  allowing the stack of pallets to drop onto the first set of flanges  142  supported by the rotatable table  120 . The shafts then rotate back to their original position. In doing so, the second flanges  115  connected to them pick up the stack of pallets as they rotate except for the bottom one which now rests on the first set of flanges  142 . The pallet stack is above the bottom of the magazine portion of the pallet presentation mechanism  110 , allowing clearance for the rotatable table  120  to rotate out from under the magazine  112  and over the forks of the sod harvester. As seen in  FIGS. 17 and 18 , when the rotatable table mechanism  120  is aligned over the pallet forks, the second set of shafts rotates to open the tray formed by the first set of flanges  142 , dropping the pallet onto the forks. The table mechanism  120  then rotates back under the magazine  112  ready to start the next cycle.  
         [0035]     When a full pallet of sod is dropped off, the forks only have to raise slightly on their way back to the stacking position to accept a pallet and would not interfere with the sod stacking arm beginning a stacking cycle. The pallet dispensing mechanism is off to the side and does not contribute to the overall length of the machine.  
         [0036]     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.