Abstract:
A mechanical harvester for harvesting a produce with a stem/core planted in a field is provided. The mechanical harvester includes a chassis, and a cutting device and a transport assembly connected to the chassis. The cutting device is configured to cut the stem/core of the produce. The transport assembly is configured to transport the cut product using a movable first belt with a first set of produce grippers and a movable second belt with a second set of produce grippers. When the produce is held between the first set and second set of produce grippers, a portion of the first set of produce grippers opposes a portion of the second set of produce grippers. The opposing produce grippers are configured to compress and exert a force on the produce to hold the produce between the movable first and second belts.

Description:
BACKGROUND 
       [0001]    1. Field 
         [0002]    The present application relates to an apparatus and method for mechanically harvesting agricultural products and, more particularly, to a mechanical harvester for harvesting produce having a stem/core, which is planted in a field, such as iceberg lettuce, romaine lettuce, celery, and cabbage. 
         [0003]    2. Description of the Related Art 
         [0004]    Typically, harvesting of produce having a stem or core, such as romaine lettuce, iceberg lettuce, celery, and cabbage, in the field is predominately done by hand. The harvesting procedure involves several steps. These steps include a person cutting the stem/core of the produce while the produce is planted in the ground, and placing the cut produce on a moving platform for subsequent processing and packing. Further, in some instances, the core of the produce is removed or extracted from the leaves by hand. This step is often performed by packers that sell prepared lettuce or prepackaged salad mixes. 
         [0005]    Previously, harvesting systems have utilized conveyor belts for movement of produce from the field. However, these conveyor belts utilize gripping mechanisms, such as teeth or pins, attached to the conveyer belts. These gripping mechanisms may pierce and damage the produce as it is transported by the conveyor belt. Produce, particularly headed lettuces such as iceberg and romaine lettuces, are susceptible to damage by teeth or pins as gripping mechanisms for transport. 
       SUMMARY 
       [0006]    In one exemplary embodiment, a mechanical harvester for harvesting produce with a stem or core planted in a field is provided. The mechanical harvester includes a chassis, and a cutting device and a transport assembly connected to the chassis. The cutting device is configured to cut the stem or core of the produce. The transport assembly is configured to transport the produce cut by the cutting device. The transport assembly includes a movable first belt and a movable second belt. The movable first belt includes a first set of produce grippers and the movable second belt includes a second set of produce grippers. When the produce cut by the cutting device is held between the first set and second set of produce grippers, a portion of the first set of produce grippers opposes a portion of the second set of produce grippers. The opposing produce grippers are configured to compress and exert a force on the produce to hold the produce between the movable first and second belts. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0007]      FIG. 1  illustrates an exemplary embodiment of a mechanical harvester; 
           [0008]      FIG. 2  illustrates an exemplary cutting device of the mechanical harvester; 
           [0009]      FIG. 3  illustrates another exemplary cutting device of the mechanical harvester; 
           [0010]      FIG. 4  illustrates an exemplary plow along with an exemplary cutting device of the mechanical harvester; 
           [0011]      FIG. 5  illustrates a perspective view of movable belts of the mechanical harvester; 
           [0012]      FIG. 6A  illustrates an exemplary schematic of the movable belts of the mechanical harvester; 
           [0013]      FIG. 6B  illustrates another exemplary schematic of the movable belts of the mechanical harvester; 
           [0014]      FIG. 6C  illustrates another exemplary schematic of the movable belts of the mechanical harvester; 
           [0015]      FIG. 7  illustrates an exemplary view of produce before it is cut by the cutting device of the mechanical harvester; 
           [0016]      FIG. 8  illustrates an exemplary view of produce being held by the movable belts of the mechanical harvester; 
           [0017]      FIG. 9A  illustrates an example of holding produce between produce grippers of the mechanical harvester; 
           [0018]      FIG. 9B  illustrates another example of holding produce between produce grippers of the mechanical harvester; 
           [0019]      FIGS. 10A ,  10 B,  10 C, and  10 D illustrate an exemplary method of transporting produce with the mechanical harvester; and 
           [0020]      FIG. 11  illustrates an exemplary view of the backend of the mechanical harvester coupled to an elevator belt. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    To provide a more thorough understanding of the present invention, the following description sets forth numerous specific details, such as specific configurations, parameters, examples, and the like. It should be recognized, however, that such description is not intended as a limitation on the scope of the present invention, but is intended to provide a better description of the exemplary embodiments. 
         [0022]    With reference to  FIG. 1 , an exemplary mechanical harvester  100  is depicted. As described below, mechanical harvester  100  is configured to harvest produce having a stem, core, or root, such as romaine lettuce, iceberg lettuce, celery, cabbage, or the like. To harvest produce in the field, mechanical harvester  100  moves through the field of produce, while cutting the stems/cores of the produce or cutting the produce from its stem/core to release the produce, lifting the released produce from the ground, and transporting the released produce. The produce may be transported to a storage bin or container for future processing, or to a processing platform connected to mechanical harvester  100  for more immediate processing. Processing may include inspection, sorting, trimming, decoring, washing, and packaging, for example. 
         [0023]    As depicted in  FIG. 1 , mechanical harvester  100  includes a chassis  102 . A cutting device is coupled to chassis  102  to cut the stem/core of the produce. 
         [0024]      FIG. 2  depicts the cutting device as a flat blade  204 . In the embodiment shown in  FIG. 2 , flat blade  204  is configured to be fixed to mechanical harvester  100  ( FIG. 1 ). As mechanical harvester  100  ( FIG. 1 ) moves through the field, flat blade  204  moves with mechanical harvester  100  ( FIG. 1 ) cutting produce in the field. The position of flat blade  204  may be adjusted during harvesting to optimize the angle and height of flat blade  204  to cut a particular type of produce. Flat blade  204  may be adjusted to change the angle of flat blade  204  in relation to the ground and the angle of flat blade  204  in relation to the direction of motion of harvester  100  ( FIG. 1 ). 
         [0025]    In addition to flat blade  204 , the cutting device may be, but is not limited to, a decoring blade, a knife, a band saw, an ultrasonic knife, a vibrating knife, or a water jet-cutting device. For example,  FIG. 3  depicts the cutting device as a decoring blade  302 . Decoring blade  302  is configured to both cut the produce from its stem/core and decore the cut produce. Decoring during harvesting in the field can reduce handling of the produce. A reduction of handling increases efficiency and reduces the risk of damage to the produce. 
         [0026]    Although a single cutting device has been depicted, it should be recognized that multiple cutting devices may be used to harvest produce from multiple rows of produce at a time. For example, in the embodiment shown in  FIG. 2 , flat blade  204  cuts produce from a single row of produce at a time. As such, multiple flat blades  204  may be included in mechanical harvester  100  ( FIG. 1 ) to cut produce from multiple rows of produce at one time. In other words, mechanical harvester  100  ( FIG. 1 ) can harvest from at least an equal number of rows of produce as the number of flat blades  204  that are included in mechanical harvester  100 . 
         [0027]    As depicted in  FIG. 4 , mechanical harvester  100  ( FIG. 1 ) may also include a plow  402  positioned in front of a cutting device. In a position forward to the cutting device, plow  402  will reach the produce before the cutting device when mechanical harvester  100  ( FIG. 1 ) is moving. Plow  402  keeps vegetation and other debris from collecting on the cutting device. In addition, mechanical harvester  100  ( FIG. 1 ) may include more than one plow, such as plow  404 , in a position forward to a wheel of mechanical harvester  100  ( FIG. 1 ). Plow  404  keeps vegetation and other debris from collecting on the wheel of the mechanical harvester  100  ( FIG. 1 ). 
         [0028]    As depicted in  FIG. 1 , a transport assembly  104  is coupled to chassis  102 . As depicted in  FIG. 2 , transport assembly  104  includes movable belts  206  and  208  configured to hold, lift, and transport the produce after the produce is cut from its stem/core. As will be described in detail below, produce gripper  210  and opposing produce gripper  212  are coupled to movable belts  206  and  208 , respectively. Produce gripper  210  and opposing produce gripper  212  are used to hold, lift from the ground, and transport the produce. For example, with reference to  FIG. 7 , a head of iceberg lettuce  702  is depicted as having been cut from its stem/core. As depicted in  FIG. 8 , produce gripper  210  and opposing produce gripper  212  hold, lift from the ground, and transport iceberg lettuce head  702 . 
         [0029]    With reference again to  FIG. 2 , movable belts  206  and  208  are attached to wheels  214  that, when rotated, will move the movable belts  206  and  208 . Movable belts  206  and  208  can be conveyor belts. 
         [0030]    As depicted in  FIGS. 6A and 6B , movable belts  206  and  208  are in a substantially parallel configuration. As depicted in  FIG. 5 , movable belts  206  and  208  can also be inclined relative to the ground from the front end to the rear end of transport assembly  104 . In this way, movable belts  206  and  208  are configured to lift the cut produce and transport the cut produce to a platform for further processing or a storage bin. As also depicted in  FIG. 5 , transport assembly  104  may include multiple sets of movable belts for harvesting from multiple rows of produce. 
         [0031]    As depicted in  FIG. 6C , a spacing  612  is defined between movable belts  206  and  208 . Spacing  612  is adjusted for the produce that will be harvested with mechanical harvester  100  ( FIG. 1 ). In the substantially parallel configuration, as can be seen in the top view depicted in  FIG. 6C , spacing  612  is substantially consistent along the length of movable belts  206  and  208  so that the produce may be carried between movable belts  206  and  208  utilizing produce gripper  210  and opposing produce gripper  212 . 
         [0032]    Sets of produce grippers  210  and  212  are formed of a pliable material, such as a pliable plastic. The pliable material may be deformed such that the produce, when between movable belt  206  and movable belt  208 , will compress produce gripper  210  and opposing produce gripper  212 . 
         [0033]    Also, as depicted in  FIG. 6C  and  FIG. 10C , produce grippers  210  and  212  are aligned such that they directly oppose each other, particularly when the cut produce is disposed between them. Note, the intermeshing of produce grippers  210  and  212  seen in  FIG. 2  is the result of the produce grippers  210  and  212  being pliable and the short spacing of movable belts  206  and  208  in  FIG. 2 . However, if the spacing of movable belts  206  and  208  is sufficient for produce grippers  210  and  212  to not contact each other, then grippers  210  and  212  directly oppose each other, as depicted in  FIG. 6C . 
         [0034]    As depicted in  FIG. 8  and mentioned above, produce gripper  210  and opposing produce gripper  212  are compressed by lettuce head  702 , because they are formed of pliable material. The rigidity of the material of the produce grippers determines the force exerted on the produce. The force exerted on the produce by each of the produce grippers is preferably at least approximately the same as the weight of the produce. The force exerted on the produce by each of the produce grippers is preferably at most approximately 200% of the weight of the produce so that the produce is not damaged. 
         [0035]    In one example, as depicted in  FIG. 9A , produce gripper  210  and opposing produce gripper  212  may contact lettuce head  702  below the midline  910  of lettuce head  702  to lift and hold the lettuce head  702 . The force exerted by the produce gripper  210  may be approximately the weight of the produce. Similarly, the force exerted by opposing produce gripper  212  may be approximately the weight of the produce. Assume, for the purpose of this example, lettuce head  702  weighs one pound. As such, produce gripper  210  and opposing produce gripper  212  each exert approximately one pound of force on lettuce head  702  to hold lettuce head  702  between produce gripper  210  and opposing produce gripper  212 . 
         [0036]    In another example, as depicted in  FIG. 9B , produce gripper  904  and opposing produce gripper  906  may contact lettuce head  902  at about the midline  912  of lettuce head  902  to lift and hold the lettuce head  902 . In this example, the force exerted by both produce gripper  904  and opposing produce gripper  906  may be 200% of the weight of the produce so that lettuce head  902  is held between produce gripper  904  and opposing produce gripper  906 . The direction of the force exerted on lettuce head  902  is primarily a lateral direction, requiring a greater force exerted by produce gripper  904  and opposing produce gripper  906  to hold lettuce head  902  off the ground than when the force exerted by the produce grippers has a greater vertical component, as depicted in  FIG. 9A . 
         [0037]    As depicted in  FIG. 7 , produce gripper  210  and opposing produce gripper  212  are cog-like protrusions. The profile of the cog-like protrusions allows mechanical harvester  100  ( FIG. 1 ) to be self-feeding. Also, as mentioned above, movable belts  206  and  208  may be configured to be inclined to facilitate lifting of the cut produce from the ground. In other words, the produce does not need to be pushed or placed into the conveyer-type movable belts. The cog-like profiles of produce gripper  210  and opposing produce gripper  212  contact the cut produce on the ground and, as movable belts  206  and  208  move, the cut produce is pulled between produce gripper  210  and opposing produce gripper  212 . The cut produce deforms produce gripper  210  and opposing produce gripper  212 . Once deformed, produce gripper  210  and opposing produce gripper  212  exert a sufficient amount of force to hold the produce between produce gripper  210  and opposing produce gripper  212  as described above. The self-feeding process increases the speed of harvesting and minimizes the number of personnel needed to operate the mechanical harvester. Furthermore, the shape of produce gripper  210  and opposing produce gripper  212  reduces the damage to the produce. 
         [0038]    Produce gripper  210  and opposing produce gripper  212  are configured to not puncture the produce. In the embodiment shown in  FIG. 7 , the dimensions of produce gripper  210  and opposing produce gripper  212  are large enough, relative to the produce being harvested, to not damage the produce by puncturing or piercing. In one example, the heights of produce gripper  210  and opposing produce gripper  212  are at least approximately 50% of the height of a cut produce. For example, an average iceberg lettuce head is six inches in height. Produce gripper  210  and opposing produce gripper  212  for gripping iceberg lettuce may be three inches in height. However, it should be appreciated that, in other examples, the height of produce gripper  210  and opposing produce gripper  212  may be less than 50% of the height of the cut produce. 
         [0039]    After a cut produce is lifted onto movable belts  206  and  208  and held by produce gripper  210  and opposing produce gripper  212 , movable belts  206  and  208  are moved to transport the produce the length of the movable belt. In other words, the produce is held between produce gripper  210  and opposing produce gripper  212  to transport the produce from one end of movable belts  206  and  208  to the other end where the produce is deposited. 
         [0040]    The transporting process is illustrated in  FIGS. 10A ,  10 B,  10 C, and  10 D. As depicted in  FIGS. 10A and 10B , the direction of travel of mechanical harvester  100  ( FIG. 1 ) brings produce grippers  210  and  212  to the lettuce head  702 . As depicted in  FIGS. 10B and 10C , produce gripper  210  and opposing produce gripper  212  contact the lettuce head  702  to lift lettuce head  702  between produce gripper  210  and opposing produce gripper  212 . As depicted in  FIG. 10C , produce gripper  210  and opposing produce gripper  212  are configured to be compressed by lettuce head  702 , such that a sufficient force is exerted on lettuce head  702  to hold lettuce head  702  between produce gripper  210  and opposing produce gripper  212 . As depicted in  FIG. 10D , while mechanical harvester  100  ( FIG. 1 ) continues to travel through the field, movable belts  206  and  208  move so that lettuce head  702  between produce gripper  210  and opposing produce gripper  212  is transported toward the rear of mechanical harvester  100  ( FIG. 1 ). 
         [0041]    As depicted in  FIG. 11 , at the rear of mechanical harvester  100  ( FIG. 1 ), movable belts  206  and  208  may deposit the produce onto a moving platform or an elevator belt  1102  to be transported to a processing platform for further processing. Processing steps may include, but are not limited to, decoring, sorting, trimming, washing, and packaging. The moving belts  206  and  208  may also deposit the produce into a storage bin (not shown). 
         [0042]    Although the present invention has been described with respect to certain exemplary embodiments, examples, and applications, it will be apparent to those skilled in the art that various modifications and changes may be made without departing from the invention.