Abstract:
A seed delivery system for use in a seeding machine that removes seed from a seed meter by capturing seed therefrom. The delivery system moves seed down to a lower discharge point and accelerates seed horizontally rearward to a speed approximately equal to the forward travel speed of the machine such that the seed, when discharged has a low or zero horizontal velocity relative to the ground. The delivery system uses a brush belt to capture, move and accelerate the seed. By capturing the seed and moving it from the meter to the discharge, each seed is held in place relative to other seeds and the planter row unit. As a result, the seeds are isolated from row unit dynamics thereby maintaining seed spacing.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a Divisional of U.S. application Ser. No. 12/364,010, filed 2 Feb. 2009. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention relates to a seeding machine having a seed metering system and a seed delivery system for delivering seed from the meter to the ground. 
       BACKGROUND OF THE INVENTION 
       [0003]    An agricultural seeding machine such as a row crop planter or grain drill places seeds at a desired depth within a plurality of parallel seed trenches formed in soil. In the case of a row crop planter, a plurality of row crop units are typically ground driven using wheels, shafts, sprockets, transfer cases, chains and the like or powered by electric or hydraulic motors. Each row crop unit has a frame which is movably coupled with a tool bar. The frame may carry a main seed hopper, herbicide hopper and insecticide hopper. If a herbicide and insecticide are used, the metering mechanisms associated with dispensing the granular product into the seed trench are relatively simple. On the other hand, the mechanisms necessary to properly meter the seeds, and dispense the seeds at predetermined relative locations within the seed trench are relatively complicated. 
         [0004]    The mechanisms associated with metering and placing the seeds generally can be divided into a seed metering system and a seed placement system which are in series communication with each other. The seed metering system receives the seeds in a bulk manner from the seed hopper carried by the planter frame or by the row unit. Different types of seed metering systems may be used, such as seed plates, finger plates, seed disks, etc. In the case of a seed disk metering system a seed disk is formed with a plurality of seed cells spaced about the periphery of the disk. Seeds are moved into the seed cells with one or more seeds in each seed cell depending upon the size and configuration of the seed cell. A vacuum or positive air pressure differential may be used in conjunction with the seed disk to assist in movement of the seeds into the seed cell. The seeds are singulated and discharged at a predetermined rate to the seed placement or delivery system. 
         [0005]    The most common seed delivery system may be categorized as a gravity drop system. In the case of the gravity drop system, a seed tube has an inlet end which is positioned below the seed metering system. The singulated seeds from the seed metering system merely drop into the seed tube and fail via gravitational force from a discharge end thereof into the seed trench. The seed tube may have a rearward curvature to reduce bouncing of the seed as it strikes the bottom of the seed trench and to impart a horizontal velocity to the seed in order to reduce the relative velocity between the seed and the ground. Undesirable variation in resultant in-ground seed spacing can be attributed to differences in how individual seeds exit the metering system and drop through the seed tube. The spacing variation is exacerbated by higher travel speeds through the field which amplifies the dynamic field conditions. Further seed spacing variations are caused by the inherent relative velocity difference between the seeds and the soil as the seeding machine travels through a field. This relative velocity difference causes individual seeds to bounce and tumble in somewhat random patterns as each seed comes to rest in the trench. 
         [0006]    Various attempts have been made to reduce the variation in seed spacing resulting from the gravity drop. U.S. Pat. No. 6,681,706 shows two approaches. One approach uses a belt with flights to transport the seeds from the meter to the ground while the other approach uses two belts to grip the seed and transport it from the meter to the ground. While these approaches control the seed path and reduce variability due to dynamic events, neither approach seeks to deliver the seed with as small as possible horizontal velocity difference relative to the ground. U.S. Pat. Nos. 6,651,57, 7,185,596 and 7,343,868 show a seed delivery system using a brush wheel near the ground to regulate the horizontal velocity and direction of the seed as it exits the seeding machine. However, there is still a gravity drop bet the seed meter and the brush wheel which produces variation in seed spacing. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention provides a seed delivery system that removes the seed from the seed meter by capturing the seed. The delivery system then moves the seed down to a lower discharge point and accelerates the seed rearward to a horizontal velocity approximately equal to the forward travel speed of the seeding machine such that the seed, when discharged, has a low or zero horizontal velocity relative to the ground. Rolling of the seed in the trench is reduced as a result of the near zero horizontal velocity relative to the ground. Furthermore, as the seed experiences a controlled descent from the point at which it is removed from the meter to a point very near the bottom of the trench, the system becomes nearly impervious to the field dynamics experienced by the row unit. The combination of controlled descent and discharge at a substantially zero horizontal speed relative to the ground reduces seed spacing variability. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a plan view of a planter having the seed delivery system of the present invention; 
           [0009]      FIG. 2  is a side view of a row unit of the planter of  FIG. 1 ; 
           [0010]      FIG. 3  is an enlarged side view of the seed delivery system of the present invention; 
           [0011]      FIG. 4  is a top view of a planter row unit showing the metering system orientation in one alternative arrangement of the metering system and delivery system of the present invention; 
           [0012]      FIG. 5  is a top view similar to  FIG. 4  illustrating the delivery system with the meter housing removed; 
           [0013]      FIG. 6  is a side view of the row unit of  FIG. 4 ; 
           [0014]      FIG. 7  is a perspective view of the seed disk used in the seed meter shown in  FIGS. 4-6 ; 
           [0015]      FIG. 8  is a sectional view along the line  8 - 8  of  FIG. 7  illustrating the orientation of the seed disk and brush or the seed delivery system of the present invention; 
           [0016]      FIG. 9  is a side view of a row unit showing the orientation of the delivery system of the present invention and a vacuum belt seed meter; 
           [0017]      FIG. 10  is a side view of another orientation of the seed delivery system of the invention with a vacuum belt seed meter; and 
           [0018]      FIG. 11  is a side view illustrating the orientation of the seed delivery system of the invention with a finger pick-up meter. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]    With reference to  FIG. 1  an example planter or seeding machine  101 , shown containing the seed delivery system of the present invention. Planter  10  includes a tool bar  12  as part of a planter frame  14 . Mounted to the tool bar are multiple planting row units  16 . Row units  16  are typically identical for agree planter but there may be differences. A row unit  16  is shown in greater detail in  FIG. 2 . The row unit  16  is provided with a central frame member  20  having a pair of upwardly extending arms  21  ( FIG. 4 ) at the forward end thereof. The arms  21  connect to a parallelogram linkage  22  for mounting the row unit  16  to the tool bar  12  for up and down relative movement between the unit  16  and toolbar  12  in a known manner. Seed is stored in seed hopper  24  and provided to a seed meter  26 . Seed meter  26  is of the type that uses a vacuum disk as are well known to meter the seed. Other types of meters can be used as well. From the seed meter  26  the seed is carried by a delivery system  28  into a planting furrow, or trench, formed in the soil by furrow openers  30 . Gauge wheels  32  control the depth of the furrow. Closing wheels  34  close the furrow over the seed. The gauge wheels  32  are mounted to the frame member  20  by arms  36 . The toolbar and row unit are designed to be moved over the ground in a forward working direction identified by the arrow  38 . 
         [0020]    The row unit  16  further includes a chemical hopper  40 , a row cleaner attachment  42  and a down force generator  44 . The row unit  16  is shown as an example of the environment in which the delivery system of the present invention is used. The present invention can be used in any of a variety of planting machine tapes such as but not limited to, row crop planters, grain drills, air seeders, etc. 
         [0021]    With reference to  FIG. 3 , the seed delivery system  28  is shown in greater detail. Delivery system  28  includes a housing  48  positioned adjacent the seed disk  50  of the seed meter. The seed disk  50  is a generally flat disk with a plurality of apertures  52  adjacent the periphery of the disk. Seeds  56  are collected on the apertures from a seed pool and adhere to the disk by air pressure differential on the opposite sides of the disk  50  in a known manner. The disk may have a flat surface at the apertures  52  or have seed cells surrounding the apertures  52 . The disk rotates clockwise as viewed in  FIG. 3  as shown by the arrow  54 . At the top of  FIG. 3 , seeds  56  are shown adhered to the disk. 
         [0022]    The seed delivery system housing  48  has spaced apart front and rear walls  49  and  51  and a side wall  53  therebetween. An upper opening  58  in the housing side wall  53  admits the seed from the metering disk  50  into the housing. A pair of pulleys  60 ,  62  are mounted inside the housing  48 . The pulleys support a belt  64  for rotation within the housing. One of the pulleys is a drive pulley while the other is an idler pulley. The belt has a base member  66  to engage the pulleys and elongated bristles  70  extending therefrom. The bristles are joined to the base member at proximal, or radially inner, ends of the bristles. Distal, or radially outer, ends  74  of the bristles touch, or are close to touching, the inner surface  76  of the housing side wall  53 . A lower housing opening  78  is formed in the side wall  53  and is positioned as close to the bottom  80  of the seed trench as possible. As shown, the lower opening  78  is near or below the soil surface  82  adjacent the trench. The housing side wall forms an exit ramp  84  at the lower opening  78 . 
         [0023]    Returning attention to the upper portion of  FIG. 3 , a loading wheel  86  is provided adjacent the upper opening  58 . The loading wheel is positioned on the opposite side of the seeds  56  from the brush  64  such that the path of the seeds on the disk brings the seeds into a nip  88  formed between the loading wheel and the distal ends  74  of the bristles  70 . At the location of the nip  88 , the air pressure differential across the seed disk  50  is terminated, freeing the seed from the apertures  52  in the disk. The bottom surface of the loading wheel, facing the seed disk  50 , has recesses  90  formed therein. The recesses  90  receive seed agitators  92  projecting from the seed disk  50 . The moving agitators, by engagement with the recesses in the loading wheel, drive the loading wheel in a clockwise rotation. 
         [0024]    In operation, the belt  64  is rotated in a counterclockwise direction. As the belt curves around the pulleys, the bristles will naturally open, that is, separate from one another as the distal ends of the bristles travel a larger circumferential distance around the pulleys than the inner ends of the bristle at the belt base member. This produces two beneficial effects as described below. The seeds are transferred from the seed meter to the delivery system as the seeds are brought by the disk into the nip  88 . There the seeds are pinched off the seed disk between the loading wheel and the bristles  70  to remove the seed from the seed disk and seed meter. The seeds are captured or entrapped in the bristles by insertion of the seed into the bristles in a radial direction, that is from the ends of the bristles in a direction parallel to the bristle length. This occurs just as the belt path around the pulley  60  ends, when the bristle ends are closing back together upon themselves, allowing the bristles to close upon, and capture the seeds therein. As the belt continues to move, the bristles more or convey the seeds downward to the housing lower opening. The side wall  53  of the housing cooperates with the bristles  76  to hold the seed in the brush bristles as the seed is moved to the lower opening. 
         [0025]    The lower opening  78  and the ramp  84  are positioned along the curved belt path around the pulley  62 . The bristle distal ends thus cause the linear speed of the seeds to accelerate relative to the speed of the belt base member  66  and the housing as shown by the two arrows  94  and  96 . The seeds are then propelled by the bristles over the ramp  84  and discharged through the lower opening  78  into the seed trench. The angle of the ramp  84  can be selected to produce the desired relationship between the seed vertical and horizontal speeds at discharge. The forward travel direction of the row unit is to the left in  FIG. 3  as shown by the arrow  38 . At the discharge, the horizontal speed of the seed relative to the ground is minimized to reduce roll of the seed in the trench. 
         [0026]    The belt shown in  FIG. 3  has relatively long bristles. As a result of the long bristles and the seed loading point being at the end of the curved path of the brush around the pulley  60  results in the seeds being loaded into the belt while the bristles have slowed down in speed. The bristle speed at loading is thus slower than the bristle speed at the discharge opening as the belt travels around the pulley  62 . This allows in the seed to be loaded into the belt at a relatively lower speed while the seed is discharged at the lower end at a desired higher speed. As described above, it is preferred that the horizontal velocity of the seed at the discharge be equal to the forward travel speed of the planter but in the rearward direction such that the horizontal velocity of the seed relative to the ground is close to or equal to zero. The long bristles can be used to increase the speed of the seed as it travels around the pulley. However, a short bristle brush can be used as well. With a short bristle brush, there will be little acceleration in the speed of the seed as the seed travels around the pulleys. The belt will have to be driven at a speed to produce the desired horizontal velocity of the seed at the discharge. Even with a short bristle brush, the seed is still accelerated in the horizontal direction. As the belt travels around the pulley, the direction of travel of the seed changes from the predominantly vertical direction, when the seed is moved downward from the seed meter, to a predominantly horizontal direction at the discharge. This produces an acceleration of the seed velocity in the horizontal direction. 
         [0027]    With the delivery system  28 , the seed is captured by the delivery system to remove the seed from the seed meter. The seed is then moved by the delivery system to the seed discharge point where the seed is accelerated in a rearward horizontal direction relative to the housing. From the seed meter to the discharge, the seed travel is controlled by the delivery system, thus maintaining the seed spacing relative to one another. 
         [0028]    In the embodiment shown in  FIG. 3 , the seed disk and the front and rear was  49 ,  51  of the housing  48  lie in planes that are generally parallel one another. As shown, the plane of the delivery system is generally parallel to the direction of travel of the row unit. Other relationships between the seed meter and delivery system are shown and described below. 
         [0029]    As shown in  FIG. 3 , the side wall  53  is divided by the upper and lower openings  58 ,  78  into two segments,  53   a  and  53   b . Segment  53   a  is between the upper and lower openings in the direction of belt travel while the segment  53   b  is between the lower and upper openings in the direction of belt travel. It is the gaps in the side wall  53  that form the upper and lower openings. It should be understood, however, that the delivery system will function without the segment  53   b  of the side wall. It is only the segment  53   a  that functions together with the belt bristles to deliver the seed from the meter to the seed trench. Thus, the term “upper opening” shall be construed to mean a open area before the side wall segment  53   a  in the direction of belt travel and the term “lower opening” shall mean an open area after the side wall segment  53   a  in the direction of belt travel. 
         [0030]    With reference to  FIGS. 4-7 , the delivery system  28  is shown in combination with the seed meter and row unit structure in an alternative arrangement of the seed meter and delivery system  28 . The seed meter  200  is shown mounted to the row unit with the seed disk  202  in a vertical orientation but at an angle to the forward travel direction shown by the arrow  38 .  FIG. 4  shows of the seed meter orientation in the row unit without the delivery system  28 . The seed meter includes a housing having two halves  204  and  206  releasable joined together in a known manner. The seed meter is driven through a transmission  208  coupled to a drive cable, not shown. 
         [0031]    In  FIG. 5  only the seed disk  202  of the meter is shown with the seed delivery system  28 . As previously mentioned, the seed disk  202  is in a vertical orientation but it does not lie in a plane parallel to the forward direction  38 . Instead, the meter is oriented such that the disk is at a 60° angle relative to the forward direction when viewed from above. The seed of delivery system  28  is generally identical to that shown in  FIG. 3  and is driven by a motor  65 . The delivery system, including of the brush belt  64 , is generally vertical and aligned with the fore and aft direction of the planter such that the angle between the brush and the seed disk is approximately 60°. The angle between the delivery system and a seed disk produces a partial “cross feed” of the seed into the brush. That is, the seed is fed into the brush at an angle to the lengthwise direction of the bristles. This is in contrast to  FIG. 3  where the seed enters the brush in a direction substantially parallel to the lengthwise direction of the brush bristles. If the brush and seed disk were oriented at 90° to one another, a total cross feed would be produced with seed entering the brush perpendicular to the bristles. 
         [0032]    The seed disk  202  is shown enlarged in  FIGS. 7 and 8 . The disk  202  has opposite sides, a vacuum side  216  and seed side  218 . The seed side  218  has a surface  219  near the periphery that defines a reference plane. The reference plane will be used to describe the features of the disk near the disk periphery. An outer peripheral lip  220  is recessed from the reference plane. The peripheral lip  220  creates a radially outward edge face  222 . A circumferential row of spaced apart apertures  224  is arranged around a circular path radially inward of the edge face  222 . Each aperture extends through the disk between the vacuum side  216  and the seed side  218 . Radially inward of each aperture  224 , there is a radially elongated recess  226 . The recess  226  is recessed axially into the disk from the reference plane. In operation, the disk rotates in a counterclockwise direction as indicated by the arrow  228 . During rotation, the recesses  226  agitate the seed in the seed pool. 
         [0033]    Surrounding each aperture  224  is a tapered recess, or shallow seed cell,  232  that extends axially into the disk from the reference plane. Seed cell  232  begins at a leading edge  234  in the direction of rotation of the disk and is progressively deeper into the seed side  218  to a trailing edge formed by an axially projecting wail  236 . The tapered recess or seed cell  232  reduces the vacuum needed to pick-up and retain seed in the apertures  2 ,  4 . The seed cell also enables the seed to sit lower relative to the seed side  218  of the disk, allowing the seed to be retained while the seed singulator removes doubles or multiples of seed from the apertures  224 . In addition, the recess well  236  agitates seed in the seed pool, further aiding in seed pick-up. The wall  236  extends lengthwise in a predominately radial direction as shown by the dashed line  238 . The walls  236 , while predominately radial, are inclined to the radial direction such that the inner end of the wall  236  is leading the outer end of the well in the direction of rotation. Immediately following each well  236 , as the disk rotates, is a projection, or upstanding peg  240  extending axially from the disk seed side. The pegs engage seed in the seed pool for agitation to aide in seed pick-up. The pegs  240  are located slightly radially inward of the circular path of apertures  224  to avoid interference with the seed singulator. 
         [0034]    With reference to  FIG. 8 , the disk  20   e  is shown in operation and in position relative to the belt  64  in the delivery system  28 . As seeds  244  are carried by the disk  202  into the bristles of the brush  64 , the wall  236  and the pegs  240  act to push the seed  244  into the bristles of the brush  64  and assist in keeping the seed from being knocked of the disk upon the seed&#39;s initial contact with the brush bristles. Once the seed is inserted into the brush bristles, the vacuum from the opposite side of the disk is cut-off, allowing the brush to sweep the seed off the disk in a predominately radial direction relative to the disk. An insert  246  overlies the lip  220  at the point of seed release to hold the seed in the brush bristles in the transition between the disk and the side wall  53  ( FIG. 3 ) of the delivery system housing. The disk  202  is inclined to the length of the brush bristles at approximately a 60 degree angle. This produces the partial cross-feed of the seed into the brush bristles. 
         [0035]      FIG. 9  shows the brush belt seed delivery system  28  in combination with a vacuum belt metering system having a metering belt  302 . The vacuum belt meter is fully described in co-pending U.S. patent application Ser. No. 12/363,968, filed Feb. 2, 2009, now U.S. Pat. No. 7,918,168 and incorporated herein by reference. The belt  302  picks-up seed at a pick-up region  304  at a lower, front location of the belts path and transports it to the delivery system at a release region  306  at an upper, rear location of the belt&#39;s path. In this arrangement of the belt meter and the brush delivery system, the delivery system is again partially cross fed with seeds from the meter. 
         [0036]    Another arrangement of the delivery system together with a vacuum meter belt is shown in  FIG. 10 . The delivery system  28  is in-line with the belt meter  124 . This allows the distal ends of the brush bristles to sweep over the surface of the metering belt  126  to capture the seed therefrom. The meter belt  126  is wrapped around pulleys  128 . The metering belt  124  is similar and functions as the belt  302  mentioned above. 
         [0037]    The delivery system of the present invention can also be used with seed meters other than air pressure differential meters. For example, with reference to  FIG. 11 , a finger pick-up meter  130  is shown, such as that described in U.S. Pat. No. 3,552,601 and incorporated herein by reference. Seed is ejected from the meter through an opening  132 . The delivery system  134  has a brush belt  136  wrapped about pulleys  138  and  140 . As shown, the belt pulley  138  shares a common drive shaft with finger pick-up meter  130 . A hub transmission such as a spherical continuously variable transmission or a three speed hub can be used to drive the belt  135  at a different speed from the meter  130 . The delivery system housing includes a side wail  142 . A ramp  146  is formed at the lower end of the wall  142  adjacent the lower opening  148 . At the upper end of the delivery system, the upper opening is formed in the housing rear wall adjacent the opening  132  through which seeds are ejected from the seed meter. The seeds are inserted laterally into the brush bristles in a complete cross-feed. As in the other embodiments, the seed is captured in the brush bristles, moved downward to the lower opening, accelerated rearward and discharged through the lower opening  148 . 
         [0038]    The endless member of the delivery system has been described as being a brush belt with bristles, in a broad sense, the bristles form an outer periphery of contiguous disjoint surfaces that engage and grip the seed. While brush bristles are the preferred embodiment, and may be natural or synthetic, other material types can be used to grip the seed such as a foam pad, expanded foam pad, mesh pad or fiber pad. 
         [0039]    Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.