Patent Publication Number: US-RE48572-E

Title: Planting unit for a seeding machine having blocking member to control hand-off of seed from a seed meter to a seed delivery system

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a reissue of U.S. patent application Ser. No. 14/215,182, filed Mar. 17, 2014, now U.S. Pat. No. 9,510,502, which is a Continuation of U.S. patent application Ser. No. 13/072,175, filed Mar. 25, 2011, now U.S. Pat. No. 8,671,856, which is a Continuation-in-part of U.S. patent application Ser. No. 12/363,968, filed Feb. 2, 2009, now U.S. Pat. No. 7,918,168. 
    
    
     FIELD 
     The following relates to a planting unit for a seeding machine and more particularly to a planting unit having a seed meter and seed delivery system. 
     BACKGROUND 
     Various types of seed meters have been developed that use an air pressure differential, either vacuum or positive pressure, to adhere seed to a metering member. The metering member takes seed from a seed pool and sequentially discharges single seeds. (In some cases, multiple seeds may be discharged at a time.) One common type of seed meter is shown in U.S. Pat. No. 5,170,909. There, a seed disk  48  contained in a housing is used to meter the seed. The seed pool is positioned on one side of the disk at a lower portion thereof while vacuum is applied to the opposite side of the disk. As the disk is rotated, individual seeds from the seed pool are adhered by the vacuum to apertures that extend though the disk. When the seed reaches a desired release position, the vacuum is terminated, allowing the seed to drop from the disk, through a seed tube to a furrow formed in the soil below. 
     Flexible belts have also been used in an air pressure differential seed meter. One example is shown in US patent application 2010/0192818 A1. There, a flexible belt having an array of apertures therein is movable along a path in a housing. A seed pool is formed on one side of the belt. Vacuum applied on the opposite side of the belt along a portion of the belt path adheres seed to the apertures, allowing the belt to move the seed to a release position where the vacuum is cut-off. The seed then falls or is removed from the belt. 
     When seed falls by gravity from the meter through the seed tube, it can be difficult to maintain accurate and consistent seed spacing at planting speeds greater than about 8 kph (5 mph). To maintain spacing accuracy, a seed delivery system that controls the seed as the seed moves from the seed meter to the soil is desirable. One such delivery system is shown in U.S. patent application 2010/0192819-A1. With such a delivery system, the hand-off of seed from the disk of U.S. Pat. No. 5,170,909 to the delivery system is difficult to achieve In a consistent manner. While the hand-off of seed may be improved with the use of a belt meter, there is still a need for a more consistent and reliable hand-of seed from the seed meter to the delivery system. 
     SUMMARY 
     A planting unit for a seeding machine is provided having a seed meter with a metering member that moves seed sequentially along a first path to a release position at which the seed is moving in a first direction and a delivery system adapted to take seed from the metering member at the release position and control movement of the seed from the seed meter to a discharge location adjacent a seed furrow formed in soil beneath the seeding machine. The delivery system, at the release position, moves seed in a second direction along a second path. A blocking member or guide located adjacent the first path immediately preceding the release position prevents movement of the seed in the second direction until the seed has passed the blocking member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a common agricultural planter; 
         FIG. 2  is a side perspective view of a planting unit frame, seed meter and seed delivery system; 
         FIG. 3  is an enlarged perspective view of the seed meter and delivery system drives; 
         FIG. 4  is a perspective view of the seed meter with the cover open illustrating the metering member; 
         FIG. 5  is an exploded perspective view of the seed meter of  FIG. 4 ; 
         FIG. 6  is a perspective view of the metering member of  FIG. 4 ; 
         FIG. 7  is side cross-section of the metering member of  FIG. 6  illustrating the orientation of the metering member installed in a seed meter mounted to a planting unit; 
         FIG. 8  is a fragmentary cross-section of an alternative metering member; 
         FIG. 9  is a elevational view of the inside of the metering member of  FIG. 6 ; 
         FIG. 10  is a side sectional view of the metering member and seed delivery system; 
         FIG. 11  is a sectional view of the hand-off of seed from the metering member to the delivery system including the delivery system brush belt; 
         FIG. 12  is a sectional view like  FIG. 11  without the delivery system brush belt; 
         FIG. 13  is a schematic illustration the direction of entry of seed into the brush belt; 
         FIG. 14  is a schematic illustration of the direction of travel of the seed on the metering member and in the delivery system at the release position of seed from the metering member; 
         FIG. 15  is side sectional view of the metering member and delivery system at the hand-off without the brush belt; 
         FIG. 16  is a perspective view of the inner side of the seed meter housing; 
         FIG. 17  is a side sectional view of the metering member and meter housing illustrating the seed pool formed by the metering member and housing; 
         FIG. 18  is side sectional view like  FIG. 17  illustrating a prior art seed meter with a disk metering member; 
         FIG. 19  is a perspective view of the lower end of the delivery system; 
         FIGS. 20 and 21  are perspective views of an alternative metering member; 
         FIG. 22  is a schematic side view of another arrangement of the seed meter and seed delivery system; 
         FIG. 23  is a perspective view of the seed meter of  FIG. 22  partially disassembled; 
         FIG. 24  is perspective view of the seed meter as seen along the line  24 - 24  of  FIG. 23 ;    
         FIG. 25  is a perspective view of the vacuum manifold of the seed meter of  FIG. 23 ; 
         FIG. 26  is a sectional view of the idler pulley mounting structure of the seed meter of  FIG. 23 ; 
         FIG. 27  is a plan view of a vacuum control member in the seed meter of  FIG. 23 ; 
         FIG. 28  is a perspective view of the seed meter housing cover of the seed meter of  FIG. 23 ; 
         FIG. 29  is perspective view of the upper end of the seed meter of  FIG. 23 ; and 
         FIG. 30  is a perspective view showing the seed meter of  FIG. 23  in relation to the seed deliver system. 
     
    
    
     DETAILED DESCRIPTION 
     An agricultural seeding machine  10  is shown in  FIG. 1  as a row crop planter. Seeding machine  10  has a central frame  12  on which are mounted a plurality of individual planting units  14 . The seeding machine  10  has a fore-aft direction shown by the arrow  15  and a transverse direction shown by the arrow  17 . Each planting unit  14  is coupled to the central frame  12  by a parallel linkage  16  so that the individual planting units  14  may move up and down to a limited degree relative to the frame  12 . Large storage tanks  13  hold seed that is delivered pneumatically to a mini-hopper on each planting unit. Each planting unit  14  has a frame member  18  ( FIG. 2 ) to which the components of the planting unit are mounted. The frame member  18  includes a pair of upstanding arms  20  at the forward end of thereof. The arms  20  are coupled to the rearward ends of the parallel linkage  16 . Furrow opening disks (not shown) are attached to shaft  22  in a known manner to form an open furrow in the soil beneath the seeding machine into which seed is deposited. Closing and packing wheels (not shown) are also mounted to the frame member  18  in a known manner to close the furrow over the deposited seed and to firm the soil in the closed furrow. A seed meter  24  and a seed delivery system  400  are also attached to the frame member  18  of the planting unit. 
     The meter  24  includes a housing  30  ( FIG. 3 ) and a cover  34 . The housing  30  and the cover  34  are coupled to one another by complementary hinge features  36  and  38  (see  FIG. 5 ) on the housing and cover respectively. Hinge feature  36  includes a pivot pin  37  coupled to the housing while the feature  38  is an integrally formed hook that wraps around the pivot pin allowing the cover  34  to pivot about the axis of the pin  37 . An elastomeric latch member  40  is coupled to the housing  30  and has an enlarged portion  42  that is seated into a socket  44  formed in the cover to hold the cover in a closed position on the housing  30 . 
     The housing  30  is formed with a second hinge element in the form of a pivot pin  46  ( FIG. 3 ). Pivot pin  46  is seated into a hook member  48  ( FIG. 4 ) of the mounting frame  50  attached to the frame member  18 . This allows the seed meter  24  to pivot relative to the planting unit frame member  18  about an axis  52 . A drive spindle  54  is carried by the housing  30  and has a drive hub  56  ( FIG. 5 ) on the end thereof. The spindle  54  couples to the output shaft  58  of electric motor  60  to drive the seed meter when in the assembled position shown in  FIG. 3 . The seed meter  24  is coupled to the delivery system by a latch mechanism  68  including a metal rod  70  having a hook at one end seated into an aperture in the meter housing  30  when latched. The delivery system further has a mounting hook  72 , partially shown in  FIG. 2 , which attaches to the planting unit frame member  18  to support the delivery system. 
     The delivery system  400  is driven by an electric motor  80 , also carried by the mounting frame  50 . The output shaft of motor  80  is connected to the delivery system through a right-angle drive  82 . While electric motors have been shown to drive both the seed meter and the seed delivery system, it will be appreciated by those skilled in the art that other types of motors, such as hydraulic, pneumatic, etc. can be used as well as various types of mechanical drive systems. 
     With reference to  FIG. 6 , a metering member  100  of the seed meter is shown in greater detail. These metering member  100  is shown as a single piece, concave bowl shaped body. The bowl shaped body has a base portion  102  from which extends a sidewall  104 . Sidewall  104  terminates in an outer edge  106 . The sidewall has a radially inner surface  108  and a radially outer surface  110 . Adjacent the outer edge  106 , the sidewall has a rim portion  112  shown by the bracket in  FIG. 6 . The rim portion  112  extends radially outwardly and axially toward the outer edge  106 . In the rim portion  112 , there is an annular array of apertures  114  that extend through the sidewall between the inner and outer surfaces  108  and  110 . The metering member  100  is mounted in the meter housing for rotation in the direction of the arrow  118  in  FIG. 6 . In operation, as the metering member rotates, individual seeds from a seed pool  120  located at a bottom portion of the metering member are adhered to the apertures  114  on the inner surface  108  of the sidewall and sequentially carried upward to a release position  164  at an upper portion of the metering member. Thus, the inner surface is also known as the seed side of the metering member. A series of raised features or projections, such as paddles  116 , extend from the inner surface  108  of the sidewall  104  typically with one paddle located behind each aperture  114  in the direction of rotation. Each paddle forms a confronting surface  124  behind the associated aperture in the direction of rotation to push the seed adhered to the aperture into the delivery system as described below. As explained above, it is the rim portion  112  of the metering member that performs the function of drawing individual seeds from the seed pool and sequentially moving seed to the release position to supply seed individually to the seed delivery system  400 . 
     The base portion  102  of the metering member contains a central drive aperture  130  ( FIG. 5 ) used to mount the metering member on a rotational drive hub  56  for rotation about the axis  132  in a manner similar to mounting a flat seed disk in a seed meter as is well known. When mounted to the housing  30 , the metering member  100  cooperates with the housing to form a trough to hold the seed pool  120  as described more fully below. The axis  132  is inclined to both a horizontal plane as well as to a vertical plane extending fore and aft of the seeding machine and a vertically plane extending transversely to the seeding machine. 
     With reference to  FIG. 7 , the metering member  100  is shown in a sectional view. The base portion  102  is a generally planar while the rim portion  112  of the inner surface of the sidewall  104  is outwardly flared, that is, extending both radially outward and axially. As shown in  FIG. 7 , the rim portion is frusto-conical. Alternatively, as shown in  FIG. 8  in connection with a metering member sidewall  104 ′, the inner surface of the sidewall rim portion  112  may be frusto-spherical in shape. Furthermore, while the rim portion  112  has been shown as being outwardly flared, the rim portion could be generally cylindrical without any outward flair, that is, extending only axially. The metering member  100  can be formed as one piece or constructed of multiple pieces. The metering member can be most easily molded of plastic such as polycarbonate, nylon, polypropylene or urethane. However, other plastics can be    used as well as other materials such as metal, etc. The metering member  100  is sufficiently rigid to be self-sustaining in shape without additional supporting structure. This is in contrast to the flexible belt metering member shown in U.S. Pat. No. 2,960,258 where it be belt member is preferably of a flexible elastomeric material and is supported within a support ring. Being self-sustaining in shape, the metering member does not need any supporting structure to hold a shape. As a self-sustaining, the metering member may be rigid or the metering member may be flexible to change shape when acted upon in a manner similar to the flexible seed disk of U.S. Pat. No. 7,661,377. 
     As previously mentioned, the metering member  100  can be mounted to a drive hub through the central drive aperture  130  in the base portion  102 . Mounting through the central drive aperture  130  provides both mounting support of the metering member as well as the rotational drive of the metering member. Alternatively, support for the metering member can be provided on the outer surface of the sidewall. A groove may be formed in the outer surface of the sidewall to receive rollers that support the metering member. If the groove is also formed with drive teeth, one of the rollers could be driven by a motor to rotate the metering member. With such alternative arrangements possible, it is not necessary that the metering member have a base portion. The function of metering seed is performed by the sidewall and thus, the sidewall is the only required portion of the metering member. 
     As shown in  FIG. 7 , the metering member  100 , when mounted in the meter housing, is oriented at an incline to the vertical as shown. In this orientation, the apertures  114  lie in a plane  150  inclined at an angle a relative to vertical. In this orientation, an upper portion  148  of the metering member overhangs or extends beyond a lower portion  154 . As described below, this allows access to the upper portion  148  of the metering member for the mechanical seed delivery system  400 . As shown, the angle a is approximately 24°. However, any angle will suffice as long as the upper portion  148  extends beyond the lower portion sufficiently for access for the seed delivery system from below the metering member at the seed release position. 
     The seed pool  120  is formed at the bottom of the metering member  100  as shown in  FIG. 9 . Vacuum is applied to the outer surface  110 , causing individual seeds to be adhered to the apertures  114  as the apertures travel through the seed pool. As the metering member rotates as shown by the arrow  118 , seed is moved upward to a release position  164  at the upper portion  148  of the metering member. The release position is slightly past the top or 12 O&#39;clock position on the circular path of travel of the seed such that the seed is moving somewhat downward at the release position. This facilitates the seed&#39;s entry into the delivery system as more fully described below. Also, by being past the top point of the path, the delivery system is off center relative to the metering member providing clearance between the delivery system and the seed meter drive. At the release position  164 , the inner surface of the rim portion of the metering member is facing downward such that seed is adhered beneath the metering member or is hanging from the metering member. See  FIG. 10 . The seed delivery system  400  is also positioned beneath the upper portion of the metering member at the release position  164  to take the seed from the metering member as shown in  FIG. 10 . 
     Delivery system  400  includes a housing  402  having a left sidewall  404  (see  FIG. 19 ) and a right sidewall  406  (see  FIG. 3 ). The terms left and right are used in relationship to the direction of travel of the seeding machine shown by the arrow  408 . Connecting the left and right sidewalls to one another is an edge wall  410 . An upper opening  416  is formed in the edge wall and sidewalls to allow seed to enter into the housing  402 . A lower opening  418  is provided at the lower end forming a discharge location  413  for the seed. A pair of pulleys  420  and  422  are mounted inside the housing  402 . The pulleys a support a belt  424  for rotation within the housing. One of the two pulleys is a drive pulley while the other pulley is an idler pulley. The belt has a flexible base member  426  to engage the pulleys. Elongated bristles  428  extend from the base member  426 . The bristles are joined to the base member at proximal, or radially inner, ends of the bristles. Distal, or radially outer, ends  430  of the bristles touch or are close to touching the inner surface of the housing edge wall  410 . 
     As shown at the top of  FIG. 10 , a seed  152  is at the release position on the metering member  100  and has just been inserted into the bristles  428  of the delivery system. At the release position, the rim portion  112  of the metering member sidewall  104  is generally tangent to the stationary inner surface  412  across which the brush bristles  428  sweep. The surface  412  is on a latch portion  66  of the housing  30 . The surface  412  is a continuation of the inner surface  414  of the delivery system housing  402 . Once the seed is captured in the delivery system, the seed moves in the direction of the belt, shown by the arrow  417 . The direction of travel of the seed immediately upon capture by the delivery system  400  is shown by the vector  438 . 
     Prior to release of the seed from the metering member, the seed is moving in the direction of vector  160  which is slightly downward into the bristles  428 . With reference to  FIG. 13 , the vector  160  of the seed direction is at an angle  161  of about 60° to the length of the bristles  428  shown by the arrow  176 . As shown in  FIG. 11 , the brush belt is positioned so that seed enters the bristles at the corner of the brush belt. The brush can be positioned so that the seed enters the brush through the distal ends of the bristles or through the side of the bristles. 
     The relationship between the seed direction vector  160  on the metering member and the seed direction vector  438  when the seed is first in the brush belt is shown in  FIG. 14  illustrating the two vectors in the plane containing both vectors at the release position  164 . The angle  163  between the vectors is at least 35° and preferably between 50° and 80°. This shows the cross-feed of the seed into the bristles, meaning that the seed, prior to the release position is moving substantially in a different direction than the brush bristles are moving. This is in contrast to the arrangement shown in FIG. 3 of the previously mentioned U.S. patent application 2010/0192819-A1 where the seed on the metering disk at the release is moving in substantially the same direction as the brush bristles. This is also the relationship by which the bristles sweep over the inner surface of the sidewall relative to the travel direction of seed. 
       FIGS. 11 and 12  show a blocking member  162  carried by the meter housing  30 . Blocking member  162  is positioned adjacent a path of travel of seed  152  leading to the release position  164  and prevents movement of seed from the metering member prior to reaching the release position. Once the seed has passed the end  174  of the blocking member  162 , the seed is free to move with the brush bristles in the direction of the vector  438  in  FIG. 10 . The blocking member ensures that the seed is consistently feed into the brush belt in the center of the belt, widthwise, rather than allowing the seed to enter the belt at random positions across the belt width. As shown in  FIG. 15 , the blocking member is located beneath the sidewall  104  of the metering member     100  between the paddles  116  and the outer edge  106  of the metering member. The confronting surfaces  124  of the paddles  116  push seed into the brush bristles. The paddles or projections  116  travel further into the brush bristles, that is deeper into the bristles from their distal ends, as the projections cross the width of the brush as seen in  FIG. 11 . Once seed is in the brush bristles, the seed is swept over the inner surface of the metering member, from the apertures  114  to the outer edge  106  of the metering member in the direction of the vector  438 . The delivery system could be arranged to sweep seed in the opposite direction, that is, away from the outer edge  106  of the metering member. 
     To further ensure consistent release of seed from the metering member and hand-off to the delivery system, an ejector  166 , carried by the cover  34  rides on the outer surface of the metering member rim portion. See  FIGS. 11, 12 and 15 . The ejector  166  is in the form of a star wheel having a number of projections  168 . The projections  168  extend into the apertures  114  from the outer surface  110  of the sidewall  104  and force seed out of the apertures  114 . The ejector is caused to rotate by rotation of the metering member  100  due to the projections  168  engaging in the apertures  114 . The ejector is mounted to the cover  34  via a pivot arm  170  and bracket  171 . The ejector  166  is biased against the metering member by a spring  172 . 
     Turning attention once again to  FIG. 4 , a flexible seal  180  is shown on the inner side of the cover  34 . This seal bears against the outer surface  110  of the metering member  100  forming a vacuum chamber within the interior  182  of the seal. A first portion  184  of the seal is spaced radially further out on the metering member than is the second portion  186  of the seal. In the area of the seal first portion  184 , vacuum is applied to the apertures  114 , causing seed to adhered thereto. There is no vacuum applied to the apertures adjacent and outside of the seal second portion  186 . A port  188  in the cover  34  is adapted to connect the interior of the cover to a vacuum source in a known manner for a vacuum seed meter. The seed release position  164  is within the vacuum chamber. Thus, the brush belt and the ejector are working in opposition to the vacuum applied to the apertures  114  to release the seed from the metering member. 
     With reference to  FIG. 16 , The inside of the housing  30  is shown. The housing includes a central boss  302  for the drive spindle  54 . The housing also includes an opening  304  to receive seed from a mini-hopper, not shown, mounted to the outside of the housing and surrounding the opening  304 . Below the opening  304 , the housing wall forms a ramp  306  extending downward toward the lower end  308  of the housing. The ramp cooperates with the inner surface  108  of the metering member to hold the seed pool  120 . The housing includes an inward projection  310  forming a cavity  314  ( FIG. 17 ) on the outside of the housing into which the upper end if the delivery system  400  is placed. The projection is open at the upper end, forming a downward looking opening  312  from the interior of the housing to the exterior. This opening  312  allows the brush belt  424  to access the inner surface of the  108  of the metering member and carry seed from the housing. 
       FIG. 17  illustrates the orientation of the metering member and the cooperation of the housing  30  and metering member  100  to form a trough for the seed pool  120  at the lower end of the metering member.  FIG. 17  shows the orientation of the metering member when the seeding machine  10  is on level ground. At the lower end of the metering member, the sidewall  104  is inclined to the vertical such that the inner surface  108  is at an angle d to the vertical vector  126 . As illustrated in  FIG. 17 , the inner surface is approximately 21° from vertical. The orientation of the housing adjacent the metering member, forming the other side of the trough, is not critical. Seed from the seed pool  120  sits on top of the inner surface  108  and a component of the force of gravity is perpendicular to the inner surface  108 . When operating on a hillside, if the meter is tilted clockwise or counter-clockwise, as viewed in  FIG. 17 , the inner surface  108  remains inclined and gravity still has a component perpendicular to the inner surface. This is in contrast to a typical disk seed meter shown in  FIG. 18  with a vertically oriented disk  320  cooperating with a housing wall  322  for form a seed pool  324 . If this meter is tilted counterclockwise as viewed, seed from the pool will still bear against the disk. However, if the meter is tilted clockwise, seed from the pool will fall away from the disk, allowing for decreased metering performance in terms of seed being picked-up by the disk. Evaluation of the meter has shown improved meter performance on a hillside when the angle d is as small as 5° and as large as 75°. Better performance is achieved when the angle d is between 10° and 50° while the optimum performance is in the range of 20° to 40°. This last range provides considerable tilting of the seed meter on a hillside in any direction before performance begins to decrease. 
     At the upper end of the metering member, at the release position  164 , the inner surface  108  has an angle f to a downward vertical vector  128  in the range of 50° to 90° with the closer to 90° being the better for hand-off of seed from the metering member to the brush belt. As shown, the angle f is approximately 68°. The different orientations of the inner surface  108  relative to vertical at the seed trough and at the release position is accomplished with a metering member that is rigid. Such variation is not possible with the flat disk metering member shown in  FIG. 18 . 
     As described above, seed is adhered to the apertures  114  in the metering member due to the vacuum applied to the outer surface of the metering member creating a pressure differential on opposite sides of the metering member. As an alternative to vacuum on the outer side of the metering member, the pressure differential can be created by a positive pressure between the housing  30  and the metering member  100 . Such a system would require seals between the metering member  100  and the housing  30  to create a positive pressure chamber. In a positive pressure arrangement, the cover  34  only serves as a cover for the rotating metering member. 
     It is possible that more than one seed will be adhered to a given aperture  114 . To prevent more than one seed at a time from being transferred to the brush belt, a pair of doubles eliminators or singulators are attached to the housing  30  along the path of seed from the seed pool to the release position  164 . The singulators are in the form of brushes  330  and  332  ( FIGS. 5 and 9 ). Brush  330  has bristles extending substantially axially and brushes seed on the apertures  114  by extending inwardly from the outer edge  106  of the metering member. The bristles of brush  330  are of varying length, to engage the seed at several discrete locations along the length of the brush  330 . The brush  332  has bristles extending substantially radially and engaging the inner surface of the metering member sidewall inside of the paddles  116  and extend along the sidewall to the apertures  114 . Both brushes  330  and  332  act to slightly disturb seed on the aperture and cause excess seed to fall off. Once removed, the excess seed falls back to the seed pool  120 . The brushes can be fixed in position or they can be adjustable to change the degree to which the brushed disturb seed on the metering member. A third brush  334  is shown which extends generally radially of the metering member. The brush  334  serves to    define a boundary to the seed pool  120 . The brushes  330 ,  332  and  334  are mounted to the housing  30 . 
     Returning again to  FIG. 10 , once seed is captured or trapped in the bristles  428 , the delivery system controls the movement of seed from the seed meter to the discharge location. The seeds are held in the bristles such that the seeds can not move vertically relative to the bristles  428  or relative to other seeds in the delivery system. Particularly, during travel of the seeds along the vertical side of the delivery system, the seeds are held on at least the top and bottom of the seeds to prevent any relative movement between the seed and the brush belt. Thus, the relative position of the seeds to one another is not affected by dynamics of the planting unit while moving across a field. The seed is carried by the bristles from the upper opening  416  to the lower opening  418  with the movement of the seed controlled at all times from the upper opening to the lower opening. 
     The lower opening  418  of the delivery system housing is positioned as close to the bottom  446  of the seed trench or furrow  448  as possible. As shown, the lower opening  418  is near or below the soil surface  432  adjacent the seed furrow. The bottom of the delivery system should be no more than one or two inches, (2.5-5 cm) above the soil surface  432 . If possible, the lower end of the delivery system should be below the soil surface  432 . The housing edge wall  410  forms an exit ramp  434  at the lower opening  418 . The lower opening  418  and the ramp  434  are positioned along the curve in the belt path around the pulley  422 . The seed, being carried by the bristle&#39;s distal ends, increases in linear speed around the pulley  422  as the distal ends of the bristles travel a greater distance around the pulley  422  than does the base member  426  of the belt. This speed difference is shown by the two arrows  440  and  442 . 
     At discharge, the seed has a velocity shown by the vector V. This velocity has a vertical component V V  and a horizontal component V H . The belt is operated at a speed to produce a horizontal velocity component V H  that is approximately equal to, but in the opposite direction of, the seeding machine forward velocity shown by arrow  408 . As a result, the horizontal velocity of the seed relative to the ground is zero or approximately zero. This minimizes rolling of the seed in the seed trench. 
     Seed can be inserted into the brush bristles at essentially an infinite number of positions. This enables the brush to be operated at the speed necessary to produce the desired horizontal velocity component to the seed, independent of the seed population. The seed meter, on the other hand, must be operated at a speed that is a function of both the forward travel speed of the seeding machine and the desired seed population. Because the belt  424  can be loaded with seed at essentially an infinite number of positions, the belt speed can be operated independently of the seed meter speed. This is not the case with other seed delivery systems, such as that disclosed in U.S. Pat. No. 6,681,706 where the delivery system of  FIG. 2  has a belt with flights to carry the seed. The belt speed must be timed to the seed meter speed to ensure that one or more flights pass the seed meter for each seed that is discharged from the meter. 
     While it is desirable to match the seed rearward velocity to the seeding machine forward velocity to minimize seed relative velocity to the soil, with some seed types, it may be necessary to operate the brush belt at a different speed to ensure the seed is discharged from the brush bristles. 
     The interior of the lower portion of delivery system housing is shown in  FIG. 19 . The delivery system housing  402  is a two-piece housing having an upper housing member  460  and a lower housing member  462 . The lower housing member carries the lower pulley  422 . The lower housing member has an upwardly extending rod portion  464  that slides within a channel formed by walls  466  and  468  in the upper housing member. Springs, not shown, push downward on the rod portion  464  to bias the lower housing member downward. The brush belt  424 , wrapped about the pulleys  420  and  422 , holds the upper and lower housing members together. The belt  424  is tensioned by the springs acting on the rod portion  464 . A U-shaped metal strip  470  is attached to the upper housing member  460  and bridges the gap  472  between the upper and lower housing members to provide a continuous surface for holding seed in the housing between the upper opening  416  and the lower opening  418 . The metal strip has a tab at the upper end thereof bent over and inserted into a slot  474  in the upper housing member  460  to hold the metal strip  470  in place. If needed, a fastener, such as a nut and bolt, may be placed through the rod portion  464  and the upper housing member  460  to fix the upper and lower housing members together. 
     Different metering members may be used for different seed types. The metering member  100  is intended for soybeans and other crops planted with a fairly close seed spacing. Corn, which is planted at a greater seed spacing uses a metering member  200  shown in  FIGS. 20 and 21 . Metering member  200  is constructed in a similar fashion as metering member  100  and like components are given the same reference numeral with the addition of  100 . However, metering member  200  has half the number of apertures  214  as the metering member  100 . To avoid the need to replace the ejector  166  when changing metering members, the metering member  200  has recess  226  extending into the sidewall  204  on the outer surface  210  of the sidewall between each aperture  214 . The recesses  226  provide clearance for the projections  168  of the ejector  166  that are arranged to be inserted in each aperture  114  of the metering member  100 . The recesses  226  are not open to the inner surface  208  of the sidewall  204 . Thus there are additional projections  228  on the inner surface of the sidewall  204  between the apertures  214 . Alternatively, the projections  228  and the paddles  216  can be formed as a single projections extending from the inner surface  208 . 
     The blocking member or guide is shown in another arrangement of the seed meter and delivery system described in connection with FIGS. 22-31 from the parent application, U.S. patent application Ser. No. 12/363,968, filed Feb. 2, 2009. with reference to  FIG. 22 , a belt meter  1200  is shown schematically to illustrate the relationship of the belt  1250  relative to the row unit structure. The belt  1250  lies in a plane that is inclined relative to all three axes, that is the plane of the belt is inclined relative to a vertical fore and aft plane, inclined relative to a vertical transverse plane and inclined relative to a horizontal plane. Furthermore, the seed pickup region  1206  is positioned at the lower end of the belt  1250  while the seed release position or location  1208  is located at the upper end of the belt  1250 . In the embodiment shown in  FIG. 22 , the seed is removed from the belt  1250  at the release location by a seed delivery system  1210 . The seed delivery system  1210  is like seed delivery system  400  described above containing a brush belt  1312  to grip and carry seed. The seed delivery system  1210  moves the seed from the seed meter belt to the lower end of the row unit between the furrow opening disks where it is deposited into the furrow formed in the soil. The seed meter  1200  is described fully below with reference to  FIGS. 23-30 . 
     The seed meter  1200  has a frame member  1220  in the form of a plate which is mounted to the row unit frame in a suitable manner. The frame member  1220  supports the upper    idler pulley  1256  and the lower drive pulley  1260  about which the belt  1250  is wrapped. A gearbox and drive motor (not shown) are coupled to the shaft  264  to drive the pulley  1260  and belt counterclockwise as viewed in  FIG. 23  and shown by the arrow  1261 . The frame member  1220  also carries a vacuum manifold  1262  having a hollow interior vacuum chamber  1266 . A vacuum port  1263  extends from the opposite side of the vacuum chamber through the frame member  1220 . The manifold  1262  has an outer wall  11268  ( FIG. 25 ) containing a main slot  1270  extending the length of the outer wall. A secondary slot  11272  extends only a short portion of the length of the outer wall. 
     The belt  1250  has an outer seed engaging face or side  11251 . The belt  1250  includes a row of first apertures  11252  which overlie the slot  1270  in the manifold  1262 . The apertures  11252  to extend through the belt, allowing air to flow through the belt. The belt further has a plurality of features  11254  formed as ribs extending from the seed face  1251 . The features  1254  each for a confronting face  1255  shown in  FIG. 29  facing in the travel direction of the belt. In this embodiment, the feature  1254  forms the confronting face  1255  extending outward from the seed side  1251  of the belt. In the embodiment shown, the features  1254  do not extend laterally to both side edges of the belt, but leaves a flat edge zone  1257  along one edge of the belt. An optional second row of apertures  1258  in the belt are positioned to pass over the secondary slot  1272  in the manifold outer wall  1268 . The apertures  1258  are only in communication with the vacuum chamber  1266  for the short portion of the path of the apertures  1258  over the slot  1272 . 
     A housing  1276  is attached to the frame member  1220  and closely positioned to the belt  1250 . A portion  1277  of the housing  1276  overlies the flat edge zone  1257  of the belt. The housing  1276 , the belt  1250 , and a cover  1278  (shown in  FIG. 28 ) form a small chamber  1279  which holds a pool of seed  1280 . A brush  1282  mounted to the housing  1276  sweeps across the face  1251  of the belt and seals the chamber  1279  at the location where the belt enters the chamber to prevent seed from escaping the chamber  1279 . Seed enters in the chamber  1279  through a suitable port, not shown, in the housing  1276  or housing cover  1278 . 
     The belt  1250  and housing  1276  form a V-shaped trough for the seed pool that extends uphill in the direction of belt travel. The confronting faces  1255  formed by the features  1254  of the belt engage the seed in the pool to agitate the seed creating a circular flow of seed as shown by the broken line  1284  of  FIG. 24 . Since the belt forms one side of the V-shaped trough, seed will always remain in contact with the belt regardless of tilt or inclination of the planter, as long as sufficient seed is present in the seed pool. An advantage of the seed meter is that when the vacuum shut off, seed on the belt falls back into the seed pool. This is in contrast to disk meters where a portion of the seed on the disk above the seed tube will fall to the ground upon vacuum shut-off. 
     The idler pulley  1256  is supported by a bearing set  1285  on a tube  1286  ( FIG. 26 ). A flange  1288  welded to the tube  1286  is attached to the frame member  1220  by bolts  1290 . A spacer  1292  is positioned between the flange and frame member  1220 . The idler pulley  1256  has a groove  1294  in its outer periphery which is in line with the belt apertures  1252 . Channels  1296  extend radially through the pulley  1256  to an annular chamber  1298  surrounding the tube  1286 . An opening  1300  in the tube  1286  provides communication between the chamber  1298  and the hollow interior  1302  of the tube. The tube is connected to the vacuum source whereby the vacuum is applied to the apertures  1252  in the belt as the belt travels over the pulley  1256 . A fork  1304  is attached to the frame member  1220  with tines  1306  seated in the groove  1294  in the idler pulley. The tines filled the groove  1294  to cut off the vacuum and create the seed release location  1208 . The tines  1306  extend from the seed release location to the vacuum manifold in the direction of rotation of the idler pulley to seal the vacuum chamber and the groove in the idler pulley. 
     The housing cover  1278  mounts to the manifold and covers the open side of the housing  1276  as shown in  FIG. 29 . A doubles the eliminator  1310  is mounted to the housing cover and, when assembled, lies on top of the belt  1250 . The doubles eliminator  1310  is roughly wedge-shaped and progressively increases in width in the travel direction of the belt to increase its coverage over the apertures  1252 . The doubles eliminated  1310  causes doubles or multiples of seed to be removed from the belt resulting in a single seed covering each aperture  1252 . 
     In operation, as the belt rotates, the confronting face  1255  engage and agitate seed in the seed pool at the bottom of the housing  1276 . Seed from the seed pool will be adhered to the belt at each aperture  1252  due to the vacuum applied to the apertures from the interior of the manifold  1262  or by positive air pressure on the seed side of the belt. By virtue of the main slot  1270 , the seeds will continue to be retained on the belt as the belt travels from the seed pick-up region  1206  to the idler pulley  1256 . Due to the groove in the idler pulley, the vacuum is maintained on the apertures as the belt travels around the pulley until the seed and the aperture reaches the tine  1306  of the fork  1304 . Upon reaching the tine  1306 , the vacuum is terminated and the seed is released from the belt  1250 . Alternatively, the seed can be mechanically removed from the belt or removed by a combination of vacuum termination and mechanical removal or the seeds can be removed mechanically while the vacuum is still applied. 
     The second row of apertures  1258  will also operate to retain a seed therein while the aperture  1258  travels over the shorter slot  1272 . By picking up seed, the apertures  1258  act to further agitate the seed pool. In addition, when the apertures  1258  reach the downstream end  273  of the secondary slot  1272 , the seed is released from the belt. The release location from the aperture  1258  causes the seed to pass over one of the apertures  1252  as the seed falls. If the aperture  1252  failed to pick-up a seed and is empty, the falling seed may be retained thereon. If the aperture  1252  is not empty, but instead picked-up multiple seeds, the falling seed may collide with the multiple seeds and assist in removing one or more of the multiple seeds. In this fashion, the falling seed operates to avoid errors in terms either no seed or multiple seeds on an aperture  1252 . 
     At the seed release position  1208 , the seed is transferred from the metering belt  1252  to the seed delivery system  1210 . The seed delivery system  1210  includes an endless member also wrapped around pulleys and contained within a housing  1322 . The housing has an upper opening  1324  through which seed is admitted into the delivery system. The endless member is shown in the form of a brush belt  1312  having bristles  1314  that sweep across the face  1251  of the belt  1250  to remove the seed therefrom. At the seed release position  1208 , a transition plate  1316  is positioned adjacent the belt  1250 . The transition plate has a curved first edge  1318  abutting the edge of the belt as the belt travels around the idler pulley. The brush belt bristles will engage a seed in the aperture  1252 A at the location shown in  FIG. 19  and will sweep the seed off the belt and across the face  1320  of the transition plate  1316  in the direction of the arrow  1321 . The confronting face  1255  behind the aperture  1252 A serves as    a back stop to prevent the brush from knocking the seed off the metering belt. The confronting face  1255  pushes the seed into the brush bristles. The downward extending tab portion  1323  of the transition plate projects into the housing of the delivery system  1210  to allow the brush to continuously trap seed as the seed moves off the belt  1250 , over the transition plate  1316  and into the interior of the delivery system housing where the seed is trapped by the brush bristles and the interior surface of the delivery system housing  1322 . A guide  1325  projects from the surface of the transition plate to guide the seed and keep the seed from being swept off the meter belt prematurely. The guide forms an upstanding wall having a first portion  1326  adjacent the path of seed on the belt  1250  immediately prior to the release position  1208 . A second portion  1328  of the upstanding wall extends in the direction of seed travel in the brush belt  1312 . Seed must pass the corner or bend  1330  in the upstanding wall before it can be moved off the meter belt  1250  by the seed delivery system. 
     The guide  1325  and blocking member  162  ensure seed entry into the brush belt in a consistent manner and in the same location across the width of the brush belt. This consistent hand-off of seed from the seed meter to the seed delivery system helps to improve placement accuracy of the seed in the furrow in the soil. 
     Having described the seed meter and delivery system, it will become apparent that various modifications can be made without departing from the scope of the accompanying claims.