Abstract:
The crop lifters include a pair of rotatable disks with rims that converge towards each other below and to the rear of their centers and that diverge from each other above and forward of their centers. As the disks are carried forward by a harvester, each pair of disks gather plant material, grasp the plant material, lift the plant material and then release the plant material above an elevating conveyor. The disks remain above the surface of the ground and are rotated by crop material as the harvester moves forward or are driven by motors. Flexible disks have rims that are forced to converge by slide bearings. Semi-ridged disks are mounted on axes that extend toward each other, upward, and forward from each disk center. A plurality of pairs of disks can be carried by one harvester. A knife severs plants from their roots forward of the conveyor.

Description:
The disclosure incorporates the crop lifter and methods disclosed in provisional patent application No. 60/362,433, filed Mar. 7, 2002, whose priority is claimed for this application. 
    
    
     TECHNICAL FIELD 
     The crop lifter is employed on a vegetable harvester to lift plant material, that has been severed from the ground, and deposit the plant material on an elevating conveyor. 
     BACKGROUND OF THE INVENTION 
     Vegetables which grow on vines and bushes such as cucumbers, zucchini and squash have heavy green foliage and heavy dense fruit. The fruit can be harvested by hand or by mechanical harvesters. When the fruit is harvested by hand, the harvest involves manually removing fruit as the fruit reaches the desired size and ripeness. For some crops, fruit is removed from a given plant a number of times. The period of time between the first removal and the last removal can vary from several days to a number of weeks. The fruit of a few crops can be harvested over most of an entire growing season. 
     Fruit picked by hand is generally relatively expensive. Some vegetables are highly desired and customers will pay a premium price. Other vegetables will not command a premium price. For vegetables that will not be purchased at a premium price, people can grow them in their gardens or they can be harvested by mechanical harvesters. Cucumbers, for example, are generally harvested by mechanical harvesters. These harvesters are whole crop harvesters that remove the entire crop in one pass through the field. Such harvesters remove some fruit that is too mature or too large as well as fruit that is immature and too small. The fruit that is too mature as well as the fruit that is immature is discarded. Mechanical harvesters reduce the cost of harvesting by machine over the cost of hand picking by a sufficient amount to more than offset the losses due to discarding fruit that is too mature and fruit that is immature. 
     Grain crops such as barley, flax, dry beans, and wheat are frequently severed from their roots and left on the ground to dry for a few days. After these crops dry, they are picked up with a pick-up attachment on a grain harvester, thrashed and cleaned. The stocks, leaves and foliage are dead, dry and lightweight. The seeds are also dry. Due to the dryness and the relatively light weight, such crop material is easy to lift off the ground and convey into a harvesting machine. 
     Vegetable crops are generally harvested before the plant or the fruit lose an appreciable portion of their water content. Cucumbers for example that have remained in the field and lost a significant portion of their total water content are no longer suitable for human consumption. It is therefore necessary to gather such fruit and transport it to a processing facility as soon as possible after the plant has been severed from the ground. 
     Vegetable harvesters, that remove the whole crop from the ground, often have blades that separate plants and fruit from their root systems. A conveyor directly behind the blade or blades, that lifts the plant material from the ground, elevates the plant material and delivers the plant material to a cleaning station and to a fruit separation station. The heavy wet crop material and fruit tends to be pushed forward by the conveyor before it is lifted up onto the conveyor. As a result some fruit is damaged and some fruit is lost. The quantity of dirt, rocks and old crop residue conveyed into the harvester is increased. 
     U.S. Pat. No. 4,965,993 discloses a vine gripping convey that clamps some leaves and vines between pinch bars, elevates and carries the crop material on the upper run of a main conveyor. The pinch bars lift some crop material and drag other crop material up onto the main conveyor. This has reduced losses and permitted an increase in the ground speed of the harvester thereby increasing harvester capacity. The pinch bars must move down below the tops of the vegetation to engage and grasp leaves and vines. As pinch bars move down into the vegetation they tend to force some leaves, stalks and vines downward where they cannot be clamped between two bars. In some crop conditions the vines remain relatively close to the ground and most of the leaves remain relatively close to the ground. In these conditions, the pinch bars cannot engage large quantities of crop material and provide only minimal assistance in conveying crop material onto the main conveyor. 
     SUMMARY OF THE INVENTION 
     The crop lifters include a disk on each side of a row of plants. Each of these disks rotate about an axis that extends from positions to the side of a plant row inward toward the plant row, forward in the direction of movement and slightly upward from horizontal. Two adjacent disks on opposite sides of a row of plants form a crop lifter. The disks of a crop lifter diverge to the front and upward from their centers. The radially outer portions of each pair of the disks make contact with each other below their hubs and to the rear of their hubs. In this position the two adjacent hubs move crop material inward toward the center of a row, clamps crop material between the two adjacent disks and lift the crop material. The two disks move out of contact with each other at or slightly below the height of their hubs and to the rear of their hubs. As the disks separate, vegetation that was lifted is dropped onto the upper portion of the forward end of the main conveyor. 
     The pairs of adjacent disks that rotate about axes that intersect at a point midway between the two disks, forward of the disk centers and above the disks axes can be driven by the crop material and forward movement of the harvester. The disk could also be positively driven if desired. 
     The crop lifters for a row of plants can also include two disks that are spaced apart and mounted on a horizontal transverse shaft. The horizontal transverse shaft is driven. Both of the disks are made from flexible material. Closure arms force the rim portions of the flexible disks together behind and below the axis of the driven shaft. Contact between the rims occurs for up to 35° about the axis of the driven shaft. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The presently preferred embodiment of the invention is disclosed in the following description and in the accompanying drawings, wherein: 
     FIG. 1 is a perspective view of a vegetable harvester with crop lifting disks mounted on a common shaft; 
     FIG. 2 is an enlarged side elevational view of crop lifting disks of FIG. 1, a cutter blade and a primary conveyor with parts broken away; 
     FIG. 3 is a top plan view of the crop lifting disks mounted on a common shaft; 
     FIG. 4 is a perspective view of a single crop lifting disk on an independent spindle; 
     FIG. 5 is a front elevational view of crop lifting disks for two plant rows mounted on independent spindles; 
     FIG. 6 is an enlarged elevational view of crop lifting disks grasping plant material with parts broken away; and 
     FIG. 7 is a schematic side elevational view of the crop lifting disks, the knife blade and the primary conveyor lower end. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The crop lifter disks  10  and  12 , as shown in FIG. 1, are part of a cucumber harvester  14 . The harvester  14  has a frame  16  supported by wheels (not shown). A tongue  18  of the frame  16  includes a hitch member  20  for attaching the crop harvester  14  to the drawbar of a tractor. The harvester  14  carries a harvesting assembly  22  for separating plant material from plant roots, cleaning conveyors  24  for separating soil and rocks from the plant material, processing assemblies (not shown) for separating fruit such as cucumbers from the vines, and a fruit storage bin  26 . A discharge conveyor  28  is provided for discharging fruit from the storage bin  26 . 
     The crop lifter disks  10  and  12 , as shown in FIGS. 1-3 are mounted on a transverse horizontal shaft  30 . The shaft  30  is driven by a hydraulic motor  32 . The shaft  30  is journalled on bearings  34  and  36  that are supported by the harvester  14  and are vertically adjustable by screws  38 . 
     A cutter blade  40  is moved forward under the ground and severs plants from their roots. As shown in FIG. 7, the cutting edge of the blade  40  is slightly forward of the shaft  30 . The position of the blade  40  relative to the shaft  30  is adjustable by adjusting the screws  38  and the bearings  34  and  36  to raise or lower the shaft  30 . 
     Disk spreaders  42  are clamped to crossbeams  44  and  46  by U-bolts  48 . The crossbeams  44  and  46  are adjustably connected to fore and aft support beams  50  and  52 . The support beams  50  and  52  are pivotally connected to a conveyor frame  54  by pins  56  and uprights  58 . The uprights  58  are connected to the support beams  50  and  52  as well as to the conveyor frame  54 . The conveyor frame  54  is pivotally attached to the harvester frame  16 . A front beam  60  is secured to the forward ends of the support beams  50  and  52 . Hydraulic cylinders  62  are connected to the uprights  58  and to the frame  16 . The cylinders  62  control the height of the forward conveyor end  64  of the primary conveyor  66  and the blade  40 . 
     Slide bearings  68  on the lower ends of the spreaders  42  engage the back sides of the flexible crop lifter disks  10  and  12  and force the peripheries  72  and  74  toward clamping engagement with each other. The disks  10  and  12  first engage each other or pinch foliage at a point  76 . The disks  10  and  12  separate from each other at a point  78  and drop the foliage and fruit connected to the foliage onto an upper run  80  of the primary conveyor  66 . The point  78  is about 35° from the point  76  about the axis of the shaft  30 . The rear ends of the spreader arms  42  are adjustably attached to the crossbeams  44  and  46  to permit adjustment of row spacing. The positions of the slide bearings  68 , the first engagement at  76  and the separation at point  78  are adjustable by threaded support members  82  and their location along the length of the spreaders  42 . Slide bearings  68  are mounted on balls  84  that permit the bearings to pivot and maintain a maximum contact area on the disks  10  and  12 . 
     Deflection of the peripheries  72  and  74  of the disks  10  and  12 , by the spreaders  42  and slide bearings  68 , into engagement between points  76  and  78  tends to deflect the peripheries away from each other on the opposite side of the shaft  30 . When the rows of plants that are being harvested are close together, the outer periphery  72  of one disk  10  may contact the outer periphery  74  of a disk  12  on an adjacent row unit crop lifter  90 . Each contact will occur generally above the shaft  30  and generally forward of the shaft. However, if two adjacent crop lifter row units  50  are close together, the contact between the outer edges  86  and  88  may extend more than 35° about the shaft  30 . 
     Row units  90  shown in FIGS. 4 and 5 have a disk  94  and a disk  96 . Each disk  94  and  96  has a concave side  98  that faces toward the other disk in a row unit  90 . The axis  100  of each disk  94  and  96  is formed by a bolt  102  that clamps a disk to a support arm  104  which is fixed to the crossbeams  44  and  46  of the harvester  14 . The axis of rotation  100  of each disk  94  and  96  extends upward, forward and inward from the support arm  104  and toward the other disk of a row unit  90 . If the support arms  104  are not sprung out of shape, the axis of rotation  100  of the disks  94  and  96  of a row unit  90  will intersect each other at the vertical center of the row unit. The intersection will also be forward and above the locations in which each axis of rotation  100  passes through a support arm  104 . 
     The disks  94  and  96  of a row unit  90  are rotated about their intersecting axes  100  by the engaged vegetation C and forward movement of the harvester  14 . The disks  94  and  96  move leaves and some vines toward the center of a row unit  90  and then clamp the vines between the two disks as the vines and to leaves enter the area where the disks are close to each other. Continued rotation of the disks  94  and  96  lifts the vines and the attached fruit. In the area where the edges  106  of the disks  94  and  96  separate from each other, the clamping forces are released and the vines and foliage drop onto a harvester conveyor like the conveyor  66  shown in FIG.  3 . 
     The disks  94  and  96  could be rotated by hydraulic motors  108  if desired. There would most likely be a separate motor  108  for each disk  94  and  96 . 
     The front end of the conveyor  66  passes along the surface of a field and attempts to pick up fruit that is not lifted by the crop lifters  10  and  12  or  94  and  96 . The action of lifting and dragging vines and fruit up the forward end  64  of the primary conveyor  66 , as the disks  10  and  12  do or the disks  94  and  96  do, tends to carry some fruit onto the conveyor that might otherwise be lost. 
     The disks  10  and  12  are substantially flat and are somewhat flexible. The disks  94  and  96  with concave sides  98  are also flexible. However, the disks  94  and  96  with a concave side  98  are less flexible than the substantially flat disks  10  and  12 . The concave disks  94  and  96  will generally engage each other between points  76  and  78  as shown in FIG.  7 . The concave disks  94  and  96  have sufficient flexibility to accommodate such contact. However, the crop material to be lifted may hold the disks  10  and  12  as well as the disks  94  and  96  out of contact with each other. If the crop material to be lifted is thick and dense, it may be desirable to space the disks from each other slightly as shown in FIG.  5 . 
     The disks  10  and  12  have peripheries  72  and  74 . The disks  94  and  96  have peripheral rims  110  and  112 . Small diameter flexible tubing  114  is threaded through apertures  116  and across the periphery of the disks  10 ,  12 ,  94  and  96  as shown in the drawing. The tubing  114  tends to grasp crop material C and limit movement of the disks  10 ,  12 ,  94  and  96  relative to the crop material. 
     The cutter blade  40  is attached to the bottom of arms  118  attached to the fore and aft support beams  50  and  52 . The blade  40  has upturned ends  120  and  122  which are pivotally attached to the arms  118  by bolts  124 . A second bolt  126  passes through a bore  128  through one of a plurality of bores  128  through each of the arms  118  and a bore through one of the upturned ends  120  and  122 . 
     During operation of the harvester  14 , the cylinders  62  lower the blade  40  into the ground so that it moves under the surface, severs the roots from the rest of the plants and leaves the fruit such as cucumbers on top of the soil. In most conditions, the blade  40  is about two inches below the surface. If the soil top surface is flat the depth of the blade  40  can be reduced. The forward conveyor end  64  of the primary conveyor  66  is just above the surface of the ground. In practice the forward end of the primary conveyor  66  is in contact with the ground at least part of the time. The disks  10  and  12  as well as the disks  94  and  96  are above the ground and above fruit such as cucumbers that might be on the ground. The disks  10  and  12  are driven at a speed which is about the same as ground speed of the harvester  14 . At this speed, the disks  10  and  12  gently gather foliage and some vines, grip the crop material, raise the crop material and attached fruit and deposit the foliage and vines and the attached fruit on the primary conveyor  66 . 
     The disks  94  and  96 , when driven by hydraulic motors  108  function the same as the disks  10  and  12 . However, due to reduced disk flexing, the disks  94  and  96  have a longer useful life than the disks  10  and  12 . 
     The disks  94  and  96  gather and grasp foliage. As the harvester  14  moves forward, the stationary crop material clamped between the disks  94  and  96  causes the disks to rotate, lift foliage and fruit and then release the raised foliage and fruit on top of the upper run  80  of the primary conveyor  66 . This lifting of fruit with the foliage reduces or eliminates the bunching of fruit and foliage in front of the conveyor  38  and reduces separation of the fruit from the vines and stems thereby reducing fruit loss and fruit damage. Reducing the buildup of material in front of the primary conveyor  66  also reduces the forces on the conveyor thereby increasing the life of the conveyor. The quantity of dirt and stones carried onto the conveyor  66  is also reduced. 
     The disclosed embodiment is representative of a presently preferred form of the invention, but is intended to be illustrative rather than definitive thereof. The invention is defined in the claims.