Abstract:
A seed meter with a flat seed disk with seed apertures on the peripheral edge of the disk results is provided. The seed pick-up on the disk edge enables a more predictable seed trajectory thereby improving the accuracy of seed spacing. With seed pick-up on the disk periphery, the seed reservoir in the meter housing is located rearward of the disk as opposed to the side of the disk, resulting in a narrowing of the meter housing, making it easier to package two meters close together for twin row planting or to lower the meter in the row unit, reducing the seed drop distance. With improved seed placement accuracy, the planter travel speed can be increased. Further efficiency is gained by a vacuum clean-out of the seed meters, reducing the time required to change seed type or variety.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a seed meter for a planter or seeder and in particular to a seed meter having a metering disk with apertures on the peripheral edge of the disk to adhere seeds thereto. 
       BACKGROUND OF THE INVENTION 
       [0002]    A common form of planter utilizes a vacuum disk seed meter for each row unit of the planter. One example of such is shown in U.S. Pat. No. 5,170,909. There, a seed disk is rotated past a pool of seeds on one side thereof. A plurality of seed cells formed by recesses in the surface of the seed disk at one or more circumferential rows of holes adjacent the outer periphery of the seed disk mechanically accelerate and eventually capture therein individual seeds from the seed pool. The individual seeds are held within the cells by a pressure differential created by a vacuum source coupled to the inside of the housing on the opposite side of the seed disk until the cells reach a discharge area. At the discharge area, the effects of the vacuum are cut off so as to release the individual seeds from the cells for discharge through a chute at the bottom of the housing to a seed furrow below. A positive pressure on the seed side of the disk can be used in place of the vacuum on the opposite side. 
         [0003]    While such seed meters function well, improvements can be made that will help to improve the crop yields and improve the planting efficiency. For example, with some crops, precise spacing of the seeds in the seed trench can improve crop yields. How the seed is released from the seed disk impacts the seed trajectory through the seed tube and the seed&#39;s ultimate placement in the seed trench. Likewise, the distance the seed drops from the seed meter to the trench will also impact the seed spacing accuracy. The shorter the seed drop, the better the control in the seed placement. Yields can also be increased with different row spacings to plant with a higher seed population. One example is twin row planting with two closely spaced seed rows. The width of current seed meters make it difficult to place two meters close together for twin row applications. Increased efficiency of planting can be accomplished with higher travel speeds during planting. However, with current seed meters, higher travel speeds decrease the accuracy of seed spacing. 
       SUMMARY OF THE INVENTION 
       [0004]    The seed meter of the present invention has a seed disk with seed apertures on the peripheral edge of the disk. This avoids having the seed fall across a portion of the seed disk face upon release. The result is a more predictable seed trajectory, improving the accuracy of seed spacing. With seed pick-up on the disk periphery, the seed reservoir in the meter housing can be located to the front or rear of the disk as opposed to the side of the disk, this narrows the meter housing, making it easier to package two meters close together for twin row planting. The narrower meter can also be placed lower in the row unit, reducing the seed drop distance. With improved seed placement accuracy, the planter travel speed can be increased. Further efficiency is gained by a vacuum clean-out of the seed meters, reducing the time required to change seed type or variety. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a side view of a planter row unit with the meter of the present invention; 
           [0006]      FIG. 2  is a perspective view of the seed meter disk showing the peripheral edge of the disk; 
           [0007]      FIG. 3  is an enlarged, fragmentary perspective view of the opposite side of the seed disk from what is shown in  FIG. 2 ; 
           [0008]      FIG. 4  is a perspective view of the one member of the meter housing illustrating the vacuum channel and seal as well as the doubles eliminator; 
           [0009]      FIG. 5  is an enlarged side view of the disk together with the seed singulator illustrating the interaction therebetween; 
           [0010]      FIG. 6  is a side view of the seed singulator as viewed from the right in  FIG. 5 ; 
           [0011]      FIG. 7  is a perspective view of the seed meter illustrating the other housing member and vacuum clean-out; and 
           [0012]      FIG. 8  is a schematic illustration of the vacuum clean out system. 
       
    
    
     DESCRIPTION 
       [0013]    With reference to  FIG. 1  a planter row unit  16  is shown mounted to transversely extending tool bar  12  in a conventional manner. The row unit  16  is provided with a central frame member  20  coupled to the tool bar by a parallelogram linkage  22  to enable vertical relative movement between the row unit and the toolbar in a known manner. Seed is stored in seed hopper  24  and provided to a seed meter  26 . The seed meter singulates seed from a seed pool and drops the individual seeds through a seed tube  28  into a planting furrow. The furrow is formed in the soil by furrow opener disks  30 . Gauge wheels  32  control the depth of the furrow and closing wheels  34  close the furrow over the seed. The gauge wheels  32  are mounted to the frame member  20  by arms  36 . The row unit  16  further includes a chemical hopper  40 , a row cleaner attachment  42  and a down force generator  44 . The toolbar and row unit are designed to be move over the ground in a forward working direction identified by the arrow  38 . Multiple row units  16  are transversely spaced along and mounted to the toolbar  12 . The row unit  16  is shown as an example of the environment in which the meter of the present invention is used. The seed meter of the present invention can be used in any of a variety of planting units. 
         [0014]    The seed meter  26  includes a seed disk  48  formed of circular member  50  ( FIG. 2 ). The circular member  50  has a first or vacuum side  52  ( FIG. 3 ) and a second or opposite side  54 . (The use of the terms “vacuum side” and “opposite side” as applied to the disk is used solely to distinguish the two sides from one another and are not intended to limit the scope of the invention. For example, as described below, a vacuum is used to adhere seed to the circular member. A positive pressure could be used in place of the vacuum.) A peripheral edge  56  at the circumference of the circular member extends axially relative to the vacuum and opposite sides of the circular member. The circular member includes a central hub portion  58  by which the disk  48  is mounted to the meter drive for rotation about an axis  60 . A plurality of apertures  64  on the peripheral edge  56  are formed by passages  65  that extend through the circular member  50  to openings  66  on the first, or vacuum, side  52  of the circular member. See  FIGS. 2 and 3 . A rib  70  is disposed in each passages to partially block the associated aperture  64  to prevent smaller seeds from lodging in the apertures. 
         [0015]    On the vacuum side  52  of the circular member there is an intermediate portion  72  extending radially from the drive hub to an outer annular portion  74  adjacent the peripheral edge. The outer annular portion  74  is axially raised from the intermediate portion  72  ( FIG. 3 ). The openings  66  are located in the raised outer ring or annular portion  74  forming an circular array of openings on the vacuum side of the circular member. Between each of the openings  66 , a recess  78  is formed in the raised outer annular portion. Likewise, between each aperture  64  in the peripheral edge  56 , a recess or groove  82  is formed. The circular member  50  rotates in the direction shown by the arrow  84 . Features on the second side of the circular member, shown in  FIG. 2  a fins  80  extending axially form confronting faces  81  in the direction of rotation. The confronting faces engage and agitate seed in the seed reservoir. In the embodiment show, the fins continue around the corner  88  at the connection of the peripheral edge and the second side forming a feature  89  radially extending from the peripheral edge. The features  89  follow the apertures  64  in the direction of rotation  84  at the forward edge  91  of each recess  82 . As an alternative, the features forming the confronting faces  81  could be recesses in the second side of the circular member  50 . 
         [0016]    The seed meter housing consists of the first and second members  90 ,  150 , the first member  90  is shown in  FIG. 4 . The first housing member carries a drive hub  92  that mates with the central hub  58  of the circular member  50 . Drive hub  92  is coupled to a drive mechanism (not shown). The circular member  50  is mounted to the first housing member  90  with the vacuum side  52  facing the inner surface  94  of the first housing member. The first housing member  90  is formed with an arcuate vacuum channel  96  which is open to the circular array of openings  66  in the circular member  50 . A resilient seal  98  around the perimeter of the vacuum channel  96  engages the axially raised outer annular portion  74  of the circular member  50  to prevent or reduce air flow therebetween. The vacuum channel has radially spaced inner and outer sides  102  and  104 . A leading end  106  and a trailing end  108 , relative to the direction of rotation, join the inner and outer sides of the vacuum channel. The leading and trailing ends of the vacuum channel are inclined or angled relative to the radial direction as shown by the broken lines  110 . The angled ends of the vacuum channel allow for a transition of the vacuum pockets over the seal at the ends of the vacuum channel. This eliminates harmonic vibration of the seal  98  that occurs with radially oriented channel ends, parallel to the radial sides of the openings  66 . The seal  98  is formed to fit the vacuum channel and has first and second arcuate segments along the radially spaced inner and outer sides  102  and  104  of the vacuum channel and first and second end segments therebetween that are inclined to the radial direction defined by the arcuate segments. The vacuum channel  96  he is coupled to a vacuum port  100  which in turn is connected to a vacuum pump to provide a vacuum or lower pressure in the vacuum channel  96 , creating a pressure differential across the apertures  64  in the seed disk. 
         [0017]    With reference to  FIGS. 4 ,  5  and  6 , a seed singulator  120  is shown and described. The seed singulator includes three rotating members such as rollers or wheels  122  rotatably mounted to a carrier  124 . The carrier  124  is movably mounted to a support arm  126  at the pivot  128 . This allows the carrier to adjust itself such that all three of the rollers  122  remain in contact with the circular member  50 . The support arm  126  is in turn movably mounted to the housing member  90  at the pivot  130 . This allows the rollers  122  to adjust for runout of the circular member  50 . That is, to adjust for the circular member not being perfectly round and/or the axis of rotation  60  not being perfectly in the center of the circular member  50 . As shown in  FIG. 5 , the peripheral edge  56  of the circular member  50  is not cylindrical about the axis  60  but is inclined radially inward from the first, or vacuum, side  52  toward the second, or opposite, side  54 . The inclined edge  56  is preferred but the benefits of the invention can be obtained with a cylindrical peripheral edge as well. The rollers  122  have a main portion  136  that is generally cylindrical in shape. The bottom side  138  of the rollers engage the peripheral edge  56  of the disk member. The roller partial covers the apertures  64  to push the seeds slightly off the apertures so that if two or more seeds are adhered to any one aperture, the extra seeds are removed. A conically shaped projection  140  extends from the bottom side  138  of the rollers  122  and forms a groove  142  into which the corner  144  of the circular member is seated. By positioning the disk corner in the groove, the disk and rollers maintain engagement regardless of the tolerances of the disk and meter housing and regardless of dynamic conditions of the planter row unit. Also, in  FIG. 5 , a lip  99  of the seal  98  is shown engaging the vacuum side of the circular member  50 . 
         [0018]    With reference to  FIG. 6 , the engagement between the rollers  122  and the circular member  50  is shown in greater detail. The rollers are mounted at slight incline to the circular member  50  such that the leading edge  132  of the roller, that is the first edge of the roller to contact the circular member relative to the direction of rotation, is closer to the circular member than the trailing edge  134  of the rollers. This results in a noticeable gap  135  between the roller trailing edge and the disk  48  that is not present at the leading edge. This orientation of the roller relative to the disk reduces the likelihood of seed fragments becoming lodged between the roller and circular member by providing an increasing gap between the two in the direction of rotation. 
         [0019]    The assembled seed meter housing is shown in  FIG. 7  with the housing second member, or cover,  150 . The cover  150  includes a seed supply chute  152  through which seed is supplied to the meter. The lower end  154  of the seed supply chute forms a seed reservoir along the peripheral edge and partially on the side  54  of the circular member. A brush or other seal member (not show) is carried by the cover along the line  156  and engages the second side of the circular member to return seeds removed by the seed singulator back to the seed reservoir. After the seed is released from the meter disk, the seed drops through the discharge chute  158  into the seed tube  28  and to the furrow in the soil below. 
         [0020]    A removable door  160  is located at the bottom of the seed reservoir to assist in cleaning unused seed from the reservoir when the operator wishes to change seed type or variety. The door edges fit into slots  161  formed in the housing cover. By removing the door  160 , remaining seed will fall from the reservoir. The door  160  is shown with an optional vacuum port  162  that can be connected to a vacuum source to remove the excess seed without the need to manually remove the door  160  from each seed meter of each row unit. The schematic drawing of  FIG. 8  illustrates the vacuum system. The vacuum pump  170  is connected to a valve  172  that is selectively switched between normal planting operation and clean-out. During normal planting operation, the valve directs the vacuum to line  174  which in turn is in communication with the vacuum ports  100  of each seed meter. This supplies vacuum, or reduced air pressure, to the vacuum channels of each meter and thereby to the apertures  64  in the circular members to allow the pick-up of seeds from the seed reservoir. For clean-out, the valve  172  is switched, connecting the vacuum to line  176  which is in communication with vacuum ports  162  in the doors  160 . The vacuum thus removes the seed from the reservoirs. If the vacuum pump  170  does not have sufficient capacity to clean all meters simultaneously, the line  174  can be coupled to a manifold with multiple valves to sequentially clean out groups of meters at a time. 
         [0021]    As with other pressure differential seed meters; while the present invention has been shown and described as using a vacuum, it is possible to use a positive air pressure to retain the seeds on the circular member  50  and the claims which follow should be interpreted to include a positive pressure system wherein the pressure in the seed reservoir is higher than the pressure in the vacuum channel unless specifically precluded by the claim language. 
         [0022]    Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.