Abstract:
A system for and a method of metering product includes an equalizing meter apparatus that more readily equalizes the distribution of product with uneven distribution systems. The metering system includes a meter roller assembly operable to meter granular product delivery between a meter box and a series of product distributors. The meter roller assembly includes a shaft in support of a series of roller sections rotatably mounted on the shaft. The roller sections include at least one fluted metering section having a series of fluted segments configured to meter granular product. The equalizing meter apparatus includes a split ring having a series of protrusions configured to engage the fluted segments of the metering section and enhance equalizing the distribution of granular product from the meter roller assembly. The split ring is operable to detach from and reconnect to the fluted metering section without disassembling the meter roller assembly.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The invention relates to an implement for metering product in an agricultural environment and, more particularly, relates to a metering roller assembly employing an equalizing device configured to enhance the metering of seed or other particulate material for application in an agricultural environment. 
   2. Discussion of the Related Art 
   Air seeders are commonly towed by tractors to apply seed, fertilizer, or micro-nutrients or any granular product to a field. It is generally advantageous to tow an air seeder in combination with a tilling implement, one behind the other, to place the seed and fertilizer under the surface of the soil. An air seeder has as its central component a wheeled seed cart which comprises one or more frame-mounted seed tanks for holding product, generally seed or fertilizer or both. Air seeders also generally include a volumetric metering system operable to measure a fixed volume of seed per unit of linear distance and a pneumatic distribution system for delivering the product from the tank to the soil. 
   The volumetric metering system is configured for distribution of product from the tank to the distribution headers of the seed tubes. The metering system typically includes a meter roller assembly employing augers or fluted cylinders (meter rollers) situated in a meter box assembly secured to below the tank. 
   Typically the meter box will have a series of outlets known as runs that each leads through the distribution lines of the pneumatic distribution system. The pneumatic distribution system generally includes an air stream operable to carry product metered by the meter roller assembly through the distribution lines to a series of secondary distribution manifolds (“headers”), which in turn distribute product to a group of ground openers mounted on the seeding implement operable to place seed in the ground. The ground openers are configured to evenly deliver the product to the span of ground (the “seedbed”) acted upon by the seeding implement. 
   The distribution headers ideally have product requirements proportional to the number of ground openers that they service. Since the number of ground openers is often not evenly divisible by the number of distribution headers, one distribution header may service a different number of ground openers than another header. Because a distribution header has one outlet port for each ground opener that it services, headers often have varying numbers of outlet ports. Therefore, in order to evenly distribute product across the width of the seeding implement, product seen by a secondary distribution header servicing ten ground openers, for example, should be less than (⅚) the amount of product seen by a secondary distribution header servicing twelve ground openers. It follows that a metering system associated with the secondary distribution header servicing fewer ground openers should therefore supply a lesser volume of product. 
   However, conventional air seeders are typically unable to properly ration product to secondary distribution headers, and therefore have problems maintaining an acceptable distribution of seed or fertilizer across the width of the seeding implement. Therefore, it is desirable to devise a metering system which can accommodate varying product requirements seen by individual meter roller assemblies which are driven by a common shaft. It is also desirable to devise a metering system which, in conjunction with a pneumatic distribution system and a seeding implement, provides substantially uniform product distribution across the seedbed. 
   Various approaches have been used in the past to meter product. One known attempt includes providing a metering system employing a meter roller assembly having metering sections that are divided between fluted (or active) segments and blank (or inactive) segments. Depending on the number of distribution headers, the meter roller assembly will consist of fluted metering sections corresponding to runs which are operational and blank roller spacers extending across the width of the runs which are not operational. Product is then delivered to the distribution headers which are connected to the runs containing the fluted metering sections, and no product is delivered from those runs which are, in effect, blanked off. 
   Known segmented meter roller systems for the metering of product have several drawbacks. U.S. Pat. No. 5,924,370 discloses a meter roller assembly that employs an equalizing disc to vary the amount of product by each fluted metering roller assembly. However, the equalizing disc is friction fit to the respective metering section. Therefore, the meter roller assembly must be taken apart to reconfigure placement of the equalizing disc on the desired metering section. U.S. Pat. No. 6,158,630 discloses a known segmented meter roller system that employs a meter roller assembly having an equalizing meter device operable to reduce the product flow in each distribution line. However, the configuration of the meter roller assembly needs to be known before assembling the meter roller sections and the respective equalizing meter device. Therefore, the known equalizing meter devices are not easily placed on a roller assembly after the meter roller assembly is factory assembled. Furthermore, the known equalizing meter devices are not detachable and re-attachable to the meter section after factory assembly. 
   Therefore, a need has arisen to provide an equalizing meter device and a method thereof that enables an operator to readily equalize a distribution of product by a meter roller assembly after factory assembly. 
   SUMMARY OF THE INVENTION 
   The present invention provides a system for and a method of metering product that more readily equalizes the distribution of product with uneven distribution systems. 
   In a first embodiment of the present invention, a meter roller assembly of an agricultural implement meters granular product delivery between a meter box and a series of product distributors. The meter roller assembly includes a shaft configured to rotate in the meter box and a plurality of roller sections rotatably mounted on the shaft. The plurality of roller sections includes at least one metering section that corresponds to at least one of the plurality of product distributors. At least one metering section includes a series of fluted segments configured to meter the granular product. The meter roller assembly also includes an equalizing apparatus having a series of protrusions configured to engage the fluted segments of the metering section. Thereby, the equalizing apparatus enhances the distribution of granular product from the meter roller assembly. The equalizing apparatus is selectively operable to detach from and reconnect to the metering section without disassembling the meter roller assembly. One embodiment of the equalizing apparatus includes a split ring having an opening operable to receive a fastener. The fastener is configured to extend through the opening to engage the fluted metering section, thereby securing the position of the equalizing apparatus on the split ring. 
   In another embodiment, the present invention provides an agricultural seeding implement that includes a frame operable to be towed by a tow vehicle, a product tank mounted on the frame and configured to retain a supply of granular product, a meter box is configured to meter the supply of granular product to a conveyance system. The conveyance system conveys the granular product to a granular product distributor configured to distribute the granular product in an agricultural setting. The implement further includes a metering assembly configured for metering granular product delivery between the meter box and the product distributors. The metering assembly includes a shaft configured to rotate in the meter box, and a plurality of roller sections rotatably mounted on the shaft. The plurality of roller sections includes at least one metering section corresponding to at least one of the plurality of product distributors. At least one metering section includes a series of fluted segments configured to meter delivery of granular product. The implement further includes an equalizing apparatus having a series of protrusions configured to engage the fluted segments of the metering section. The equalizing apparatus is selectively detachable from and reconnectable to the metering section without disassembly of the metering apparatus. 
   The present invention also provides a method of equalizing a flow of granular product by a metering system, the metering system including a pre-assembled plurality of meter roller sections secured on a shaft with a shaft fastener. The method includes the acts of attaching an equalizing meter apparatus to one of more plurality of meter sections pre-assembled on the shaft; securing a position of the equalizing meter apparatus; detaching the equalizing meter apparatus from the metering system without disassembling the metering system; and re-connecting the equalizing meter apparatus to the pre-assembled metering system. 
   Other objects, features, and advantages of the invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout. 
       FIG. 1  illustrates an air cart in accordance with the present invention. 
       FIG. 2  illustrates detailed cross-section view illustrating the meter box assembly of the air cart of  FIG. 1 . 
       FIG. 3  illustrates a detailed plan view of the metering system of  FIG. 1 . 
       FIG. 4  shows an exploded view of a meter roller assembly in accordance with the present invention. 
       FIG. 5  illustrates a detailed perspective view of an equalizing meter device of  FIG. 4 . 
       FIG. 6  illustrates a detailed front view of the equalizing meter device of  FIG. 5 . 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   A wide variety of metering assemblies for metering product could be constructed in accordance with the invention defined by the claims. Hence, while preferred embodiments of the invention will now be described with reference to a seed product conveyed by an air cart, it should be understood that the invention is in no way so limited. The type of forced air conveying apparatus or machine (e.g., spreader, etc.) can vary. While the description refers to use of the present invention to convey seed product, the invention can be utilized to convey a wide variety of product (e.g., seed, fertilizer, herbicide, pesticide, micro-nutrients, etc.) and is not limiting on the invention. In addition, the type and size of the seed product (e.g., soybean, corn, cereal grains, oil seeds, etc.) can vary. 
   Referring to  FIGS. 1–3 , a metering system  20  in accordance with a first embodiment of the present invention is combined with an agricultural implement. The preferred agricultural implement shown is a conventional air cart  25 . The air cart  25  is of a known general configuration and comprises a tank  30 , or optionally a number of tanks (not illustrated), which may be mounted on a frame  35 , which is in turn carried on wheels  40 . The metering system  20  is mounted on the bottom  50  of the tank  30 . A blower  55  forces air past the outlet  60  of the metering system  20  to carry product P from the metering system  20  to appropriate runs to distribution headers on a soil working implement (headers and implement not shown). 
   A series of dividers  70  at the metering system outlet  60  define the series of runs which direct product P into a corresponding series of distribution lines  72  leading to the distribution headers on the soil working implement. In addition to dividers  70 , the metering system  20  includes a meter box  75  having an agitator  80  and a meter roller assembly  85  in accordance with the present invention. 
   Referring to  FIGS. 3 and 4 , one embodiment of the meter roller assembly  85  in accordance with the present invention includes a shaft  87  (preferably of hexagonal configuration) configured for rotation in the meter box  75  of the air cart  25 . The shaft  87  is preferably driven by a hydraulic motor, but the type of drive can vary. 
   The meter roller assembly  85  is configured for an air cart  25  having several runs, and the number of runs can vary. The metering roller assembly  85  includes one or more metering sections  95  in communication with a respective run  72 . The one or more metering sections  95  can include blank sections  100  and fluted metering sections  105 . The blank section  100  includes an outer spacer  115  and an inner spacer  120  and a pin  125  configured to blank out unused runs. Preferably, the unused runs are centrally grouped so that a single extended blank section  100  can be used across the unused runs. The fluted metering sections  105  include a plurality of extensions or flutes  130  radially configured to meter the delivery of product to the distribution lines. The fluted metering sections  105  include a coarse metering section  131 , a fine metering section (not shown), and an extra-fine metering section (not shown). The size and proportions of the flutes  130  and the type of metering sections  105  can vary depending on the type of metered product and the volume required. The disposition of the metering sections  105  can vary. 
   Referring to  FIG. 4 , a series of bearing seats  135  abut against the inner spacer  120  and include a hexagonal bore so that the bearing seats  135  rotate with the shaft  87 . The bearing seats  135  abut a machined shoulder within the outer spacer  115 . When bearings  137  are seated on the seats  135 , the outer races of the bearings  137  are in frictional engagement with the outer spacer  115 , thus allowing the inner spacer  120  to rotate, while the outer spacer  115  is held against rotation by virtue of the cap screw  138  abutting against a part of the top of the meter box  75 . A bearing shield  140  is forced against the surface of the bearing seat  135  to engage an 0-ring seal  145  between the two. 
   The metering sections  100  and  105  abut against the bearing shields  140 . Outer bearing seats  135  carry similar bearings  137  separated from the outer ends of the metering roller sections  100  and  105  by a second set of bearing shields  140 . The outer bearing seats  135  are pinned by associated pins  150  to maintain the position of the sections  100  and  105  between them. The outer bearings  137  receive the shaft  87 . The number of bearings  137  can vary from a roller assembly  85  without a center blank section to roller assembly  85  with a center blank section  100 . Thereby, the metering sections and the blank sections simply abut one another. 
   Still referring to  FIG. 4 , preferably the metering sections  100  and  105  somewhat compress together for sealing purposes. The outer seats  135  and their associated pins  150  generally maintain the compression across the metering roller assembly  85 . Covers  160  are applied at the end of the roller assembly  85  to seal the meter roller assembly  85  to the meter box  75 . 
   Referring to  FIGS. 2–4 , the other end of the meter roller assembly  85  includes an identification disk  170  operable to identify the type of metering roller assembly  85  (e.g., metering extra fine, fine, or coarse granular product). A cam arrangement  175  is fixed to the end of the shaft  87  by a pin  180  and is operable to drive the agitator  80  ( FIG. 2 ) to ensure smooth flow of product P from the product tank  30  into the meter box  75 . 
   Referring to  FIGS. 2 and 3 , the combined width of the fluted metering sections  105  and the blank sections  100  is essentially the same as the width of the meter box  75 . In a typical air cart  25 , there might be eight runs emanating from the meter box  75  and thus up to eight metering sections. Typically a run is about three inches wide, so that the metering roller assembly  85  would then be about twenty-four inches long. The variety of fluted metering sections  105  and blank sections  100  are interchangeable on the shaft  87 . 
     FIGS. 3 and 4  illustrate that the meter roller assembly  85  includes a large number of compressed pieces that is difficult to manufacture and assemble due to the possibility of the tolerances on each piece adding together in the assembly process. Although compression of the meter roller assembly  85  eliminates bearing contamination by the product, a drawback is that the compression causes difficulty in assembling the meter roller assembly  85  without specific tooling. 
   To reduce inventory and re-assembly costs, the meter roller assembly  85  of the present invention includes an equalizing meter apparatus  190 . The equalizing meter apparatus  190  is configured to mount on one or more of the flutes  130  of the fluted metering sections  105  of the metering roller assembly  85  after the configuration of the seeding implement is known and the metering roller assembly  85  is pre-assembled. 
     FIGS. 5 and 6  illustrate detailed views of a preferred embodiment of the equalizing meter apparatus  190 . The preferred equalizing meter apparatus  190  includes a disc-shaped split-ring  192  having a series of protrusions  195  and valleys  197  configured to engage or mate with the flutes  130  of the fluted metering sections  105  of the meter roller assembly  85 . The equalizing meter apparatus  190  further includes a first free end  200  and a second free end  205  configured to be separable by an applied force to selectively detach and attach the equalizing meter apparatus  190  without disassembling the meter roller assembly  85 . The spring tension of the equalizing meter apparatus  190  then brings to free ends  200  and  205  together to attach the apparatus  190  to the fluted meter section  105 . 
   A preferred embodiment of the free end  205  includes an extension  206  that is trapezoidal-shaped having a free end wider relative to a coupled end. The free end  200  includes a trapezoidal-shaped notch  207  having a narrowing opening relative to a wider base. The trapezoidal shaped notch  207  of end  200  is configured to receive the trapezoidal shaped extension  206  of end  205 , forming a dovetail joint  208 . The dovetail joint  208  secures a position of the equalizing meter apparatus  190  on a fluted metering section  105 . The ends  200  and  205  are further configured to include an opening  210  extending through the dovetail joint  208  coupling the free ends  200  and  205  and fluted meter sections  105 . The opening  210  is preferably a hole operable to receive a fastener  215  to secure the dovetail joint  208 . The fastener  215  and dovetail joint  208  secure the equalizing meter apparatus  190  in position on the fluted metering section  105 . 
   A preferred fastener  215  is a self-tapping threaded screw. One end  220  of the fastener  215  is configured to insert flush with a tapered portion  217  of the opening  210  at the exterior edge of the disc-shaped apparatus  190 . The other end  225  of the fastener  215  is configured to extend beyond the opening  210  and engage or embed into the meter section  105 , thereby securing the equalizing apparatus  190  in position on the fluted meter section  105 . The type of opening  210  (e.g., threaded or unthreaded) and the type (e.g., bolt, threaded screw, etc.) of fastener  215  can vary. Furthermore, the fastener  215  can be secured to the fluted meter section  105  using other types of securing means (e.g., latch, clamp, etc.). Another embodiment of the equalizing meter apparatus can include a split ring having a first leg and a second leg pivotal about a hinge. 
   If the air cart  25  is connected to a different seeding implement with a different distribution system, the equalizing meter apparatus  190  can be detached and easily re-connected when required without disassembly and re-assembly of the meter roller assembly  85 . In contrast, known meter roller assemblies must be re-configured (i.e., disassembled and re-assembled) to attach and/or remove a known equalizing meter apparatus and equalize uneven distribution of different types of products to different soil implements with different distribution line configurations. The equalizing meter apparatus  190  of the invention also saves a farmer from having to purchase additional roller sections to minimize the workload. 
   Referring to  FIGS. 4 and 5 , the equalizing meter apparatus  190  is preferably placed toward a center of the metering section  105  to normalize metering efficiencies with different products. The dovetail joint  208  and the fastener  215  secure and hold the position of the equalizing meter apparatus  190  on the meter section  105 . If the equalizing meter apparatus  190  were to drift to one side of the fluted metering section  105 , the characteristics of the metering operation would change. 
   One embodiment of the fluted metering sections  105  and the equalizing meter apparatus  190  are comprised of polyurethane material, but the composition of the equalizing meter apparatus  190  can vary. Any suitable adhesive may be used for joining the fluted metering sections of the meter roller assembly  85  where the sections  105  are molded separately and then joined. However, the equalizing meter apparatus  190  allows variations in the construction of the fluted metering sections  105  and blank sections  100  as a single molded unit. This has the advantage that metered product is prevented from contaminating the meter roller assembly and the metering system. In contrast, known meter roller assemblies  85  are assembled at individual blank sections  100  in order to attach and detach known equalizing meter devices. 
   In operation, one aspect of the equalizing meter apparatus  190  is to allow the meter roller assembly  85  to operate at an increased rotational speed, as measured in rotations per minute (rpms). At the increased rotational speed, any given meter roller assembly  85  is operable to deliver a larger quantity of product P. 
   The equalizing meter apparatus  190  of the present invention is configured to decrease the capacity of the fluted metering section  105  of the metering roller assembly  85  in delivering product to the distribution system. Thereby, the shaft  87  can be operated at higher rotational speed while delivering the same amount of product P to the distribution header at the soil implement as would have been delivered under a full-width fluted metering section. This aspect of the equalizing meter apparatus  190  allows product P to be readily handled which could not have been handled at a lower rotational speed. A drawback of known meter roller assemblies in delivering product P at a lower rotational speed (e.g. 2 rpm) is causing significant time periods when no flow of product P is moved during a pass of the flute  130 . These time periods of not product flow results in an undesirable pulsing effect in the delivery of product P. Known meter roller assemblies are particularly known to cause time periods of no-flow in the delivery of large-size, low-volume product P (e.g., corn) at a sufficiently low rpm (e.g., 2 to 3 rpm) to efficiently deliver proper amounts of the product P. The equalizing meter apparatus  190  of the invention is configured to allow the meter roller assembly  85  of the present invention to operate at an increased rotational speed, (e.g., 4 to 6 rpm), thereby enhancing the ability of the meter roller assembly  85  to more readily handle the larger-sized, low-volume types of product P. The equalizing meter apparatus  190  also enhances efficient operation of variable rate hydraulic drives at the increased rotational speed. 
   The embodiments of the metering system  20  and meter roller assembly  85  described above is described in combination with the standard air cart  25  having the central hopper tank  30  and the pressurized air source  55 . However, it is understood that the metering system  20  of the present invention is adaptable for use with a stand-alone blower and/or a product storage tank, as well as adapted for incorporating with other types of agricultural implements mounted on a planter (e.g., no air cart). Furthermore, each of the above described embodiments of the metering system  20  of the invention can be constructed integrally with an air cart  25 , or as a modular unit that can be coupled to a pre-assembled standard air cart structure. 
   Furthermore, one skilled in the art will recognize that the present invention is not limited to the conveyance of seed product. The present invention can be used to convey numerous types of products (e.g., seed, fertilizer, herbicides, pesticides, micro-nutrients, etc.) that exhibit suitable properties for forced air conveyance. 
   Many changes and modifications could be made to the invention without departing from the spirit thereof. The scope of these changes will become apparent from the appended claims.