Abstract:
The present invention is a seed metering disc for the distribution and planting of various sizes of seeds. The seed metering disc is defined by a set of seed cells which can accommodate various seed sizes in that each cell is defined by a recess, seed cell retention wall, and seed cell retention plate.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
       [0001]    This application is a continuation of U.S. patent application Ser. No. 09/952,405 filed Sep. 14, 2001, which claims priority to U.S. Provisional Application No. 60/232,735, filed on Sep. 15, 2000, the entire disclosures of which are incorporated herein by reference. 
     
    
     
       BACKGROUND OF INVENTION  
         [0002]    The present invention is directed to a universal seed metering disc. In particular, it relates to a seed metering disc with a seed retention plate defining a seed cell. It finds particular application in use with varying sizes of seeds.  
           [0003]    In many agricultural areas, large planters equipped with numerous row units are used to plant crop fields. The row units follow the planter and discharge seeds into the soil at a selected rate. In order to create uniformity and proper crop distance, seed meters are attached to the row units. Large seed reservoirs store the seeds as the planters move across the crop fields. Seeds are released from the seed reservoirs and are evenly dispersed between the row units. The seeds travel down the row unit and are discharged onto a rotating seed disc wherein the seeds gravitate into a series of specially-molded seed pockets, spaced to provide adequate crop distance. The seeds are retained in the seed pockets and then individually enter seed cells located at the periphery of the seed discs. The seed cells are typically sized to retain a single seed of a particular size and deliver it to the soil at a fixed point in the rotation of the seed disc. See, e.g., U.S. Pat. No. 5,058,766 assigned to Kinze Mfg. Due to the design of the seed cells, seed metering discs will only distribute seeds properly if the seeds are of the size the seed discs are designed to handle. Therefore, when planting more than one type of crop, and thus using different seed sizes, more than one set of seed metering discs must be purchased and installed to allow for proper seed metering. While the large size seed metering discs can be used for smaller seeds, the design of the seed cells for large discs does not allow for proper delivery of small seeds to the soil. Instead of falling at the designated seed delivery point, the smaller seeds slip from the seed cells at various points during seed disc rotation and are thus delivered in a non-uniform pattern. Typically, the smaller seeds fall out the backside of the seed cell and therefore fall to the soil outside the designated crop row.  
         SUMMARY OF INVENTION  
         [0004]    The present invention relates to a seed metering device and more particularly to an improved universal seed metering device which permits the planter to use one set of seed metering discs to properly deliver seeds of varying sizes to the designated crop rows. It provides a seed retention plate located on the backside of a seed metering disc for reducing seed loss through the backside of a seed cell, thereby allowing smaller seeds to be properly dispersed using larger seed metering discs.  
           [0005]    An advantage of the present invention is that seeds of varying sizes may be planted by one metering disc or one set of metering discs. Still further advantages of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of embodiments of the present invention. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0006]    In the accompanying drawings which are incorporated in and constitute a part of the specification, embodiments of the invention are illustrated, which, together with a general description of the invention given above, and the detailed description given below, serve to exemplify the principles of the invention.  
         [0007]    [0007]FIG. 1 is a front view of an improved universal seed metering disc; and  
         [0008]    [0008]FIG. 2 is a cross-sectional view of the disc of FIG. 1. 
     
    
     DETAILED DESCRIPTION  
       [0009]    The present invention is an improved seed metering disc for a seed planter which provides for universal seed use. Referring to FIG. 1 and FIG. 2, an exemplary improved universal seed metering disc  10  comprises a seed disc  20  and a seed retention plate  30 . Seed disc  20  has a front side  41  and a backside  42 , wherein the front side has a plurality of grooved seed pockets  50  and seed cells  55 . The seed pockets  50  are generally radially situated around the front side  42  of the seed disc  20 . Each of the seed pockets  50  comprise a channel which leads directly into a seed cell  55 . Each channel may be round and smooth to facilitate seed movement within the seed pockets  50 . Each seed cell  55  has a recess  66 , a seed delivery opening  67  and seed cell retention walls  68 . Each seed cell  55  is further defined by seed retention plate  30  affixed to the seed disc  20  such as to form a backside of each seed cell  55  where the recess  66  ends at break  69 .  
         [0010]    Seed retention plate  30  is substantially similar in shape and diameter as the seed disc  20  and is made from any suitable material, including a weather-safe durable material, such as a coated aluminum. The seed retention plate  30  can be affixed to the seed disc  20  by any appropriate fastening means, including a set of one or more fastening bolts  70  that pass through the front side  41  of the seed disc  20  and through the seed retention plate  30  where the bolts can be secured by one or more locking nuts. The locking nuts should be fastened tightly such as to provide contact or near contact between the seed disc  20  and the seed retention plate  30 , wherein the distance between seed disc  20  and seed retention plate  30  is small enough to prohibit seeds from sliding between the seed disc  20  and the seed retention plate  30 .  
         [0011]    In one embodiment, as shown in FIG. 2, a gasket  80 , comprised of either sponge, foam, or other suitable material, is placed between the seed disc  20  and the seed retention plate  30 . The gasket assists in holding the seeds in the seed cells  55  by increasing the friction force which the seed must overcome in order to slide from the seed cell  55 . The gasket  80  further provides a means for ensuring contact or near contact between the seed disc  20  and the seed retention plate  30 , and fills any space therebetween.  
         [0012]    Seeds stored in a seed reservoir of a planter are dropped onto the seed disc  20  which is rotating in a vertical plane along a shaft which contacts and retains the seed metering disc  10  through the shaft hole  85 . In an embodiment, more than one seed metering discs  10  are used by dividing the planter into a set number of row units, connecting one seed metering disc  10  per row unit, and evenly delivering seeds from the seed reservoir to each of the row units.  
         [0013]    The seed disc  20  rotates at a set speed creating a centrifugal force which, along with a brush system as described in U.S. Pat. No. 5,058,766, forces the seeds into the seed pockets  50 . The rotational force pushes the seeds along the channel of the seed pockets  50  until the seeds reach the seed cells  55 . The seeds then fall individually, or in small seed packets, into the recess  66  of seed cells  55  and are retained within the seed cells  55  by the seed retention walls  68  and the seed retention plate  30 . Smaller seeds that would otherwise slide out break  69  and out the backside  42  in the recess  66  of the seed cell  55  are held in place by the seed retention plate  30 . When the seed metering disc  10  reaches a fixed point in its rotation, the seeds are thrust from the seed cells  55  out the seed delivery opening  67  and into the corresponding crop row.  
         [0014]    While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in detail, it is not the intention of the applicant to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. Therefore, the invention, in its broader aspects, is not limited to the specific details and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of the applicant&#39;s general inventive concept.