Abstract:
A pneumatic on-demand seed delivery system wherein seed from the auxiliary hopper enters the seed meter through an opening beginning rearward of the vertical axis of the seed meter. And a retrofit kit for existing on-demand seed delivery systems, and method of retrofitting such existing pneumatic on-demand seed delivery systems, so as to provide an auxiliary hopper that communicates seed to the seed meter through an opening beginning rearward of the vertical axis of the seed meter.

Description:
BACKGROUND 
   There is an increased awareness among the agricultural community as to the economic importance of planting accuracy. This increased awareness and the desire to improve seed meter accuracy is due in part to the recent increase in the price of corn. For example, with corn prices near $4 per bushel, improving the seed singulation accuracy of a seed meter by a single percentage point can translate into eight dollars ($8.00) more per acre. Accordingly, there is a significant need to provide a seed meter that will consistently produce seed singulation accuracies of 98% or above. 
   With respect to vacuum type seed meters, a number of factors can affect seed singulation accuracies. One such factor is the treatment applied to the seeds. The seed corn industry is applying new formulations and heavier treatments to the seed to protect the seed from new pests and other insects and disease, but which are also more environmentally friendly. These new treatments can make the seed surface rough, thereby affecting entrainment over the apertures of vacuum disks. Additionally, some of these new treatments can become sticky, requiring more aggressive agitation of the seeds within the seed pool of the meters in order to keep the seeds from sticking together. 
   One type of vacuum meter that has experienced commercial success in recent years is the John Deere Pro-Series™ Meter found on Deere&#39;s central-fill or bulk-fill planters such as disclosed in U.S. Pat. Nos. 6,581,533 and 6,935,255 both of which are incorporated herein by reference. While the Pro-Series™ Meter may serve its intended purpose certain factors can effect its performance. 
   For example, as previously identified, certain heavily coated seed treatments may cause the seed within the seed pool to stick together reducing the flowability of the seed. Thus, unless the seed is aggressively agitated by the seed disk as it rotates through the seed pool, the reduced flowability may result in poor loading of the seed onto the apertures of the seed disk, which translate into seek skips in the furrow. Deere&#39;s standard seed disks for the Pro-Series™ Meter do not provide very aggressive agitation. As a result, under some conditions when using Deere&#39;s standard disks, the performance or accuracy of the seed meter can be less than desirable. 
   In order to overcome this problem, farmers have attempted to replace Deere&#39;s standard seed disks with after-market disks that have larger or deeper ribs or fins to provide more aggressive agitation of the seeds. While these deeper ribs provide more aggressive agitation to keep the seed pool fluid, it has been found that some of these after-market disks can increase the likelihood for the seed meter to overfill which can lead to meter performance problems or failures. 
   It has been determined that the potential for overfilling of the Pro-Series™ Meter when using seed disks designed to provide greater seed pool agitation, is partially attributed to the size and position of the opening within the seed meter housing through which the seed enters the seed reservoir from the auxiliary hopper. As will be explained in more detail later, when using larger or deeper ribs, more seeds are scooped up by the larger ribs which, due to the size and position of the opening, the void created by the seeds scooped up by the larger ribs is replenished with new seeds entering from the auxiliary hopper. Thus, in such circumstances, more seeds continually enter the seed reservoir than are actually being discharged out of the seed meter. As the seed disk rotates, the extra seeds carried by the larger ribs are returned to the seed pool which further adds to the seed pool that has already been replenished. Accordingly, over time, the meter can overfill. 
   Deere made an attempt to eliminate the tendency of the Pro-Series™ Meter to overfill by positioning a brush as a sort of lid to hold back or prevent the seed from rising above the seed reservoir. This brush lid is shown in U.S. Pat. No. 6,581,533 (see FIG. 4 of &#39;533 patent at reference numeral 68). While Deere&#39;s approach was moderately successful, where more aggressive agitation on the disk is needed, the brush lid does not sufficiently prevent over filling. Additionally, the presence of the brush can have an adverse effect upon meter performance as some seed types and sizes of seeds are physically disturbed by the brush while the seeds are being loaded on the seed disk, thereby causing unwanted skips. 
   Accordingly, there is a need for a cost effective solution that will enable farmers to modify or retrofit their existing Pro-Series Meters to overcome the deficiencies described above while not having to replace the entire seed meter. Similarly, there is a need for a new design which can be adopted by original equipment manufacturers or after-market suppliers to overcome the deficiencies associated with the existing Pro-Series design with minimal retooling or changes to the seed meter and with minimal changes to the on-demand delivery system structure. 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a partial side elevation view of a conventional central-fill agricultural planter illustrating a conventional product-on-demand delivery system such as manufactured by Deere &amp; Company. 
       FIG. 2  is a more detailed perspective view of a portion of the central-fill planter of  FIG. 1  illustrating a conventional Pro-Series™ seed meter and auxiliary hopper. 
       FIG. 3  is a more detailed perspective view of the conventional Pro-Series™ seed meter and auxiliary hopper of  FIG. 2 . 
       FIG. 4  is a side elevation view of the interior of the conventional Pro-Series™ seed meter and auxiliary hopper of  FIG. 2 . 
       FIG. 5  is a perspective view from the same perspective as  FIG. 2  illustrating one embodiment of an auxiliary hopper assembly of the retrofit kit of the present invention and/or of the improved on-demand seed delivery system of the present invention wherein the vent is incorporated into the auxiliary hopper. 
       FIG. 6  is a side elevation view of the retrofit kit and/or improved on-demand seed delivery system of  FIG. 5  showing the reduced opening beginning rearward of the vertical axis of the seed meter in relation to the original opening of the Pro-Series™ Meter shown in phantom lines. 
       FIG. 7  is an exploded perspective view of the retrofit kit of  FIG. 6 . 
       FIG. 8  is an exploded perspective view of an alternative embodiment of the auxiliary hopper assembly of the retrofit kit of the present invention and/or of the improved on-demand seed delivery system of the present invention wherein the vent is incorporated into the inlet pipe of the auxiliary hopper. 
       FIG. 9  is an exploded perspective view of yet another embodiment of the retrofit kit of the present invention and/or of the improved on-demand seed delivery system of the present invention wherein the eSet® offset seed disk system is being utilized. 
   

   DETAILED DESCRIPTION 
   Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views,  FIG. 1  illustrates a conventional central-fill planter  10  such as manufactured by Deere &amp; Company, and which utilizes a Pro-Series™ Meter&#39;s as disclosed in U.S. Pat. Nos. 6,581,533 and 6,935,255 previously incorporated herein by reference. 
   The central fill planter  10  includes a main frame  12  having a main tool bar  28  from which a plurality of spaced row units  14  are supported by a parallel linkage  16 . The parallel linkage  16  enables the individual row units  14  to move vertically independently of one another to conform to terrain or upon encountering an obstacle during planting operations. Each of the individual row units  14  comprises a “mini-hopper” or “auxiliary hopper”  18 , the purpose of which will be described later. Additionally, each row unit  14  includes a seed meter  20 , a furrow opener  22  and a furrow closing assembly  26 . The main frame  12  also supports a main or central hopper  36  and an air pump or blower  38 . The main hopper holds a bulk supply of seed. 
   In operation, the blower  38  pneumatically transfers seed from the central hopper  36  via product supply hoses  48  to each of the individual auxiliary hoppers  18  as needed, hence this type of central fill system is referred to as a “product-on-demand” delivery system. The seed meter  20  meters seed received from the auxiliary hopper  18 . The furrow opener  22  forms the planting furrow in the soil surface into which the individual seeds metered at regularly spaced intervals by the seed meter  20  are deposited after being directed downwardly and rearwardly by the seed tube  24 . The closing assembly  26  pushes the soil back into the furrow covering the seed. 
   The on-demand delivery of seed to the auxiliary hoppers  18  is regulated or controlled through a venting system. As best illustrated in  FIG. 2 , each auxiliary hopper  18  includes a vent  50  disposed in a sidewall of the auxiliary hopper  18 . Within the auxiliary hopper  18  is a downwardly curving, perforated air separation tube  52 . As seed is communicated from the main hopper  36  to the auxiliary hopper  18  via the product supply hose  48 , air escapes through the perforations  54  thereby separating the seeds from the air stream. The seeds drop into the bottom of the auxiliary hopper  18  from the bottom of the perforated air separation tube  52  and the air escapes through the vent  50  in the sidewall of the auxiliary hopper  18 . As the auxiliary hopper  18  fills with seed, the perforations  54  in the perforated air separation tube  52  get covered with seed. As the perforations  54  are covered, the volume of air that can escape through the perforations is reduced, thus reducing the air flow through the tube  52 , which, in turn, reduces the amount of seed being carried to the auxiliary hopper  18  by the product supply hose  48 . As the seed within the auxiliary hopper  18  is consumed by passing into the seed meter  20 , the seed level will drop, exposing more of the perforations  54  and allowing more air, and thus more seed, to flow once more into the auxiliary hopper  18 , thereby maintaining a steady supply of seed within the auxiliary hopper  18 . 
   As best illustrated in  FIG. 3 , the auxiliary hopper  18  is mounted to the back housing member  74  of the seed meter  20 . The meter/hopper assembly  18 / 20  is supported at a forward end by a bracket  56  disposed between the upright posts  58  of the row unit  14 . A base bracket  55  helps support the meter/hopper assembly  18 / 20  above the furrow opener  22 . A latch  57  secures the meter/hopper assembly  18 / 20  to the frame  59  of the furrow opener  22 . 
   A hex-shaft  60  is supported parallel to the tool bar  28  and is operably driven by the rotation of the ground wheels (not shown) as the planter is pulled through the field. The rotation of the hex-shaft  60  operably drives the seed meter  20  by rotating the seed meter drive shaft  62  which is, in turn, operably connected to the hex-shaft  60  via forward and rearward gearboxes  64 ,  66  and a flexible shaft  68 . The seed meter drive shaft  62  is substantially coaxial with the central axis of the seed meter  20 . 
   The Pro-Series™ meter  20  comprises a housing  72  which includes a back housing member  74  and a front housing member  76 . Disposed within the housing is a seed disk (not shown for clarity) such as disclosed in U.S. Pat. No. 5,170,909 to Lundie et al. (the “Lundie &#39;909 Patent”), incorporated herein by reference. The seed disk rotates within the housing  72  coaxially with the drive shaft  62 . As illustrated in the Lundie &#39;909 Patent, the seed disk includes a plurality of radially spaced apertures near its outer periphery. 
   In operation, seed is communicated from the auxiliary hopper  18  into the seed reservoir of the seed meter  20  through an opening  80 . A negative pressure source (not shown) draws air from the seed meter  20  from the side of the seed disk opposite the seed reservoir, thereby producing a pressure differential on opposing sides of the seed disk. This pressure differential causes the seeds within the seed reservoir to become entrained or “loaded” over the apertures as the disk rotates through the seed reservoir. As the disk rotates past a seal (not shown) disposed within the seed meter  20 , the source of the vacuum is isolated thereby eliminating the pressure differential causing the seeds to fall from the face of the disk. The falling seed is received within a seed tube  24  where it is directed downwardly and rearwardly into the seed furrow created by the furrow opener  22 . 
   Referring to  FIG. 4 , it can be seen that the opening  80  through which the seed is communicated from the auxiliary hopper  18  into the seed reservoir begins at approximately the 5 o&#39;clock position, or approximately ¾ inch forwardly of the vertical axis  82  of the seed meter  20 . The opening extends arcuately rearwardly as viewed in  FIG. 4  to approximately the 8:30 position. As previously described, it has been determined that with the opening  80  extending forwardly of the vertical axis  82  of the seed meter, excess seeds enter the seed reservoir when the seed disk rotates through the seed reservoir, particularly if a seed disk with more aggressive agitation ribs are utilized, which, over time, can result in overfilling of the meter  20 . 
   In order to minimize the chance of overfilling occurring even when utilizing seed disks with very aggressive agitation, while still utilizing much of the seed meter structure and the on-demand-delivery structure of the Pro-Series™ meter, one embodiment of the present invention is directed to a cost effective solution in the form of a retrofit kit. Additionally, rather than a retrofit kit, an original equipment manufacturer and/or an aftermarket supplier could incorporate the structural and functions features as disclosed herein to overcome the deficiencies associated with the existing Pro-Series™ meter design with minimal retooling or changes to the seed meter and with minimal changes to the existing on-demand delivery system structure. 
     FIG. 5  is a perspective view of one embodiment of a preferred retrofit kit  100  for a Pro-Series™ meter.  FIG. 6  is a side elevation view of the retrofit kit embodiment of  FIG. 5 .  FIG. 7  is an exploded perspective view of the retrofit kit embodiment of  FIG. 5 . The preferred retrofit kit  100  includes a replacement auxiliary hopper  102  which replaces the existing auxiliary hopper  18 . The replacement auxiliary hopper  102  includes appropriate mounting structure  104  that cooperates with the existing structure of the planter and which preferably utilizes or takes advantage of the same connection points on the back housing member  74  of the seed meter  20  as the auxiliary hopper  18  being replaced. As illustrated in  FIG. 7 , the mounting structure  104  includes a forward bracket  106  that cooperates with the bracket  56  on the planter  10  to support the forward end of the replacement auxiliary hopper  102 . In this embodiment, a perforated air separation tube  108  and vent  110  preferably substantially similar to the perforated air separation tube  52  and vent  50  of the original auxiliary hopper  18  are utilized. In comparing position of the replacement auxiliary hopper illustrated in  FIGS. 5-7  to the position of the original auxiliary hopper being replaced as illustrated  FIGS. 3 and 4 , it should be apparent that the replacement auxiliary hopper  102  of the retrofit kit  100  is positioned rearward of the seed meter drive shaft  62  as opposed to forward of the drive shaft  62  as in  FIGS. 3 and 4 . Accordingly, an extension pipe  112  is provided to connect the perforated air separation tube  108  to the product supply hose  48 . 
   The replacement auxiliary hopper  102  preferably includes an opening  114  which, as best illustrated in  FIG. 6 , preferably begins rearward of the vertical axis  82  of the seed meter  20  (preferably at about the 7 o&#39;clock position) and extends arcuately rearwardly in toward the horizontal axis  83  (preferably to approximately the 8:30 position). As a result, the opening  114  through which seed enters the seed meter  20  is reduced, permitting the seed meter  20  to operate more like the type of meter disclosed in the Lundie &#39;909 Patent. 
     FIG. 8  illustrates an alternative embodiment of a retrofit kit  200  of the present invention. In this embodiment the replacement auxiliary hopper  202  is substantially similar to the previously described embodiment, in that the replacement auxiliary hopper  202  includes appropriate mounting structure  204  that cooperates with the existing structure of the planter  10  and which preferably utilizes or takes advantage of the same connection points on the back housing member  74  of the seed meter  20  as the auxiliary hopper  18  intended to be replaced. As illustrated in  FIG. 8 , the mounting structure  204  includes a forward bracket  206  that cooperates with the bracket  56  on the planter  10  to support the forward end of the replacement auxiliary hopper  202 . 
   Unlike in the previous embodiment, however, an air separation tube  208  is incorporated into the extension pipe  212 , thereby eliminating the need for the vent and perforated air separation tube within the auxiliary hopper. The air separation tube  208  includes slots  210  through which air escapes. A vent regulator  211  may be provided for positioning over the slots  210  to increase or decrease the amount of air flow through the slots  210 . In this embodiment, the auxiliary hopper  202  will maintain a level of seed at a height approximate the top of the aperture  213  in the sidewall of the hopper into which the extension pipe  212  is received. A vent cover  216  preferably mounts over the slots  210  in the air separation tube  208 . The vent cover  216  preferably includes a first set of slots  218  through which air can escape to atmosphere and a second set of slots  220  in communication with the interior of the seed meter  20  to ensure adequate air flow through the seed meter for proper performance. 
   As with the previous embodiment, the replacement auxiliary hopper  202  preferably includes an opening  214  which preferably begins rearward of the vertical axis  82  of the seed meter  20  (preferably at about the 7 o&#39;clock position) and extends arcuately rearwardly toward the horizontal axis  83  (preferably to approximately the 8:30 position). As a result, the opening  214  through which seed enters the seed meter  20  is reduced, permitting the seed meter  20  to operate more like the type of meter disclosed in the Lundie &#39;909 Patent. 
     FIG. 9  illustrates additional components that may be used for retrofitting an existing Pro-Series™ meter by taking advantage of the offset disk system as disclosed in Applicant&#39;s co-pending application Ser. No. 11/465,164 (Pub. No. US2007/0039529), which is incorporated herein by reference, the commercial embodiment of which is sold under the trademark eSet®. Although  FIG. 9  illustrates the replacement auxiliary hopper embodiment  202  as just described with respect to  FIG. 8 , it should be appreciated that the replacement auxiliary hopper embodiment  102  as illustrated in  FIGS. 5-7  may also be utilized with the eSet® system. The back housing member  74  to which the auxiliary hopper  202 / 102  mounts is not shown in  FIG. 9 . The eSet® system includes the offset disk  300 , a liner  302  which is received within the interior of the back housing member  74  and secured thereto by suitable fasteners  304 . The liner  302  includes an opening  306  which mates with the opening  214 / 114  of the auxiliary hopper  202 / 102 . The eSet® system further includes the singulator  308 , brush assemblies  310 ,  312  and fragment extractor  314  all as disclosed in the above-referenced &#39;164 application. 
   The foregoing description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment of the apparatus and the general principles and features described herein will be readily apparent to those of skill in the art. Thus, the present invention is not to be limited to the embodiments of the apparatus and methods described above and illustrated in the drawing figures, but is to be accorded the widest scope consistent with the spirit and scope of the appended claims.