Abstract:
A seeder ( 20 ) includes a seed hopper ( 22 ) that feeds seed by gravity to a seed dispenser ( 24 ). The seed feed wheels ( 38 ) of the seeder are mounted in a seed metering tube ( 30 ) so that rotation of the seed feed wheels meters the output of the seeds. The seed feed wheels can be formed in segments ( 50  and  60 ) so that by matching different segments, different sizes of seed receiving detents can be used for dispensing the seeds. An adjustment bracket ( 72 ) shifts the seed feed wheels so that different sizes of detents can register with the openings of the seed metering tube ( 30 ), thereby achieving the desired matching of sizes of detents with the sizes of the seeds.

Description:
FIELD OF THE INVENTION 
   This invention concerns a method and apparatus for aerating turf and other ground cover vegetation, and for dispensing seeds from a seed hopper carried with the aerator to the aerated turf. More particularly, the invention concerns a seed dispenser that can be expediently adjusted for dispensing seeds of different sizes. 
   BACKGROUND OF THE INVENTION 
   Various devices have been developed in the past that are used in the treatment and care of turf such as grass or other ground covers of lawns, ball fields, golf courses, and the like. It is desirable to aerate the turf so as to enable air, moisture and nutrients to reach the roots of the grass, etc. The aeration of turf generally is performed by forming a pattern of holes in the turf. The holes tend to disturb the soil and roots beneath the surface of the ground cover, and when moisture and fertilizer are applied to the turf, the root structure of the turf is able to directly absorb these nutrients and thereby the growth of the root structure is stimulated, making the turf healthier. 
   A typical aerator includes a rotary drum having spikes or tines mounted to and extending radially from the cylindrical surface of the drum. The drum is moved across the turf and the tines tend to penetrate the turf so that the drum and tines “walk” across the turf. The aerator is usually pulled behind a tractor with the aerator rotating against the turf in response to the forward motion of the tractor. 
   Some of the prior art aerators have had a plurality of hollow coring tines that penetrate the turf and cut a generally cylindrical core or plug in the turf. When the coring tines are pulled away from the turf, they usually lift the plug out of the ground, leaving a residue of cores of soil on the surface of the ground. The residue of cores of soil is undesirable on lawns and on playing fields such as golf courses and baseball fields where the condition of the surface of the turf is very important to the sports person. A type of core producing aerator is disclosed in U.S. Pat. No. 4,773,486. 
   An improvement over the aerators that utilize coring tines is described in U.S. Pat. No. 5,209,306, the disclosure of which is incorporated herein in its entirety. The tines of the aerator are solid so that no core of soil is formed, and the power take-off from the tractor is connected to the aerator so that the tines are moved in an oscillating motion so that they “wobble” as they rotate with the aerator. This wobbling movement tends to enlarge the holes in the turf that are formed by the tines, thereby enhancing the amount of aeration and the degree in which the moisture, fertilizer, etc. can penetrate the turf. 
   In many situations, it is desirable to simultaneously dispense seeds to the turf and simultaneously penetrate the turf with the aerator, so as to re-seed the turf. The usual method for applying seeds to the turf is to load a hopper with seeds and progressively feed the seeds from the hopper to a seeder at the exit of the hopper. The seeder may be in the form of a plurality of cylindrical wheels. The perimeter surface of each cylindrical wheel has a series of seed detents oriented circumferentially thereabout, and the seeds from the hopper fall into the detents and move with the seed feed wheels to an outlet where the seeds drop, usually through a conduit, to the ground below the apparatus. 
   The use of seed feed wheels in seeders is common and has been in wide use for a long time. However, when the type of seed is to be changed in the hopper, such as changing from a small seed like Centipede or Bent Grass seed or Bermuda seed to a larger seed such as Fescue seed, or vice versa, it is desirable to change the feed wheels so that the detents in the feed wheels are the right size to accommodate the seeds. 
   Another method to accommodate a change in seed size is to carry two seeders on one machine, one inactive while the other one operates. The different size seeds could be placed in the separate hoppers of the dual seeder. However, seeders are usually operated in environments where they dispense the same sized seeds over a long period of time, without requiring a more expensive dual hopper arrangement. Therefore, the more typical situation is to use a single hopper seeder with single sized seed feed wheels that must be changed out when the size of the seeds is changed. 
   Accordingly, it can be seen that it would be desirable to produce an apparatus that performs the function of accurately seeding turf and, when appropriate, being adapted for expedient exchange of seed feed wheels when the size of the seeds being dispensed is to be changed. 
   Another desirable aspect would be that the quick change seed feed wheel assembly be utilized with an improved turf aerator such as disclosed in U.S. Pat. No. 5,209,306 that avoids depositing soil plugs on the surface of the turf and that forms the more desirable larger lateral dimensions in the openings below the surface of the turf for receiving the seeds from the seed hopper and inducing improved growth of the root structure of the ground cover. It is to these features that this invention is directed. 
   SUMMARY 
   Briefly described, the present invention comprises a seed dispensing apparatus for dispensing seeds of different sizes in a broadcast pattern on the soil. The apparatus includes a cylindrical seed metering tube defining at spaced intervals along its length a series of pairs of seed openings. Each pair of seed openings includes a seed entrance opening and a seed discharge opening, the seed entrance openings being positioned on one side of the seed metering tube and the discharge openings positioned diametrically opposite to the entrance openings. A plurality of seed feed wheels are positioned in the seed metering tube with each seed feed wheel positioned in alignment with a pair of seed openings of the seed metering tube. The seed feed wheels each include a pair of lines of seed detents oriented circumferentially about the seed feed wheel with the detents of one of the lines of seed detents being of greater size than the seed detents of the other line of seed detents for feeding seeds of different sizes through the dispenser. A feed wheel positioner is used for shifting the seed feed wheels along the length of the cylindrical seed metering tube. This permits one of the lines of seed detents of each seed feed wheel to be moved toward registration with the pairs of seed openings of the seed metering tube as the other lines of seed detents are moved out of registration with the pairs of seed openings. 
   With this arrangement, the operator of the seed dispensing apparatus can shift the seed feed wheels incrementally so as to expose more or less of the seed detents to the pairs of seed openings of the seed metering tube, thereby dispensing more or fewer seeds from the seed hopper. 
   Seed delivery conduits extend from each of the seed discharge openings of the cylindrical seed metering tube toward the turf for guiding the seeds from the seed discharge openings to the turf. 
   In one embodiment of the invention, the seed feed wheels each include wheel segments positioned side by side. The seed detents of one wheel segment are larger than the seed detents in the other wheel segment. The composite seed feed wheels made from the segments having different sized detents are capable of dispensing different sized seeds. 
   In an embodiment of the invention, the wheel segments each include a smooth cylindrical bearing surface positioned adjacent the line of seed detents. 
   The invention may also include the improved soil aerator, with the soil aerator mounted adjacent the seed metering tube of the seed dispenser, with the soil aerator including tines for penetrating and aerating the soil, and a following turf smoothing roller. The smoothing roller rolls over the aerated turf and smoothes the turf where the tines have been withdrawn from the turf. A rotary power means such as the smoothing roller that engages and rotates on the ground and a rotary drive means such as a chain and gear arrangement extends between the seed feed wheels, and the rotary power means rotates the seed feed wheels in timed relationship with the advancement of the invention over the ground. With this arrangement, when the forward motion of the apparatus pauses or changes velocity, the seeder will respond by changing its velocity so that its velocity corresponds directly to the rotational velocity of the smoothing roller. This avoids differences in the amount of seed dispensed to the turf. 
   With this arrangement, when the smoothing roller is lifted from the turf and terminates its rotation, the rotation of the seed feed wheels also terminates, thereby terminating the dispensing of seed. Thus, seed is dispensed only when the soil is being aerated. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic side elevational view of the seed dispensing apparatus, showing the hopper partially filled with seed, the seed feed wheels and a portion of the aerator. 
       FIG. 2  shows the drive mechanism extending between the smoothing roller and the seed feed wheels. 
       FIGS. 3 and 4  are isometric views of a segment of a seed feed wheel, with  FIG. 3  showing the right side of the segment and  FIG. 4  showing the left side of the segment. 
       FIG. 5  is a front elevational view of the right side of the seed feed wheel segment of  FIGS. 3 and 4 . 
       FIG. 6  is a perimeter view of the seed feed wheel segments of  FIGS. 3-5 . 
       FIGS. 7 and 8  are isometric views of a segment of a seed feed wheel, with the segment having smaller detents than the segments of  FIGS. 3-6 , with  FIG. 7  showing the right side of the seed feed wheel segment and  FIG. 8  showing the left side of the seed feed wheel segment. 
       FIG. 9  is a side view of the seed feed wheel segment of  FIGS. 7 and 8 . 
       FIG. 10  is a perimeter view of the seed feed wheel segment of  FIGS. 7-9 . 
       FIG. 11  is an isometric view of a pair of seed feed wheels mounted on a central drive shaft, with the seed feed wheel segments having their detents juxtaposed. 
       FIG. 12  is an isometric view of the rectilinear cylindrical seed metering tube, showing openings in the tube for the passage therethrough of seeds toward the detents of the seed feed wheels. 
       FIG. 13  is an isometric view, similar to  FIG. 12 , but having a portion thereof broken away to expose more surfaces of the seed feed wheels. 
       FIG. 14  is a front elevational view of a wheel position adjustment means for shifting the drive shaft and its seed feed wheels incrementally along the length of the cylindrical seed metering tube, for exposing more of or less than the seed detents of each wheel segment. 
       FIG. 15  is an isometric view of the assembled seed dispensing apparatus, with parts broken away for revealing one of the seed feed wheels. 
   

   DETAILED DESCRIPTION 
   Referring now in more detail to the drawings, in which like numerals indicate like parts throughout the several views,  FIG. 1  illustrates a seeder  20  that includes a seed hopper  22  and seed dispenser  24  that are mounted on a framework towed behind a tractor or other self propelled vehicle (not shown). An aerator  25  is mounted to the same framework and seed can be dispensed from the seeder  20  in a broadcast pattern either before or after the aerator. 
   A supply of seed  26  is contained within the seed hopper  22  and the seed hopper has a lower seed outlet opening  28  that faces the seed dispenser  24 . 
   As shown in  FIGS. 1 ,  12 ,  13  and  15 , the seed dispenser  24  includes a rectilinear cylindrical seed metering tube  30  that receives seed from the seed hopper outlet opening and dispenses it in predetermined quantities to a plurality of seed delivery tubes  32 . The seed metering tube  30  has a series of pairs of seed openings, each pair including a seed entrance opening  34  that registers with the hopper seed outlet opening  28 , and a seed discharge opening  36  that registers with a seed delivery conduit  32 . 
   A plurality of seed feed wheels  38  are positioned in the seed metering tube  30 , with each seed feed wheel in registration with the pairs of seed entrance openings  34  and seed discharge openings  36 . The seed feed wheels  38  rotate as indicated by the arrows  40  and meter the seeds from the seed supply  26  through the seed metering to the seed delivery tubes  32 . 
   The aerator  25  includes an array of radially extending tines  42  that are mounted about an axle, with the tines being rotatable about the axle so that they “walk” across the turf  44 . The aerator is disclosed in greater detail in U.S. Pat. No. 5,209,306, such that a detailed explanation of its structure and function is not necessary. 
     FIG. 2  illustrates a chain drive  46  that extends between the rear smoothing roller  47  of the aerator  25  and the axle  70  of the seed dispenser  24 , whereby rotation of the smoothing roller  47  results in simultaneous rotation of the seed feed wheels  38 . In instances where the size of the seeds to be dispensed from the seeder is to be changed, it might be necessary to change the size of the sprockets of the chain drive. This might depend upon the capacity of the seed feed wheels  38 . A chart (not shown) is provided by the producer of the seeder to determine the best combination of sprockets and seed feed wheels to use with a specific seed. To facilitate the change of sprockets, the length of the chain of the chain drive is longer than necessary to make proper engagement with the teeth of all of the sprockets, and an idler sprocket assembly  48  is used to adjust the chain length. The sprockets  49 A and  49 B of the idler sprocket assembly are pivotable about a common axis on opposite sides of the drive chain as indicated by arrows  49 C and  49 D to take up the slack in the drive chain. This permits forming more slack in the chain while the sprockets are being exchanged, and then tightening the chain about the replacement sprockets. 
   While the smoothing roller  47  is disclosed as a rotary power source and the chain drive  46  is disclosed as a rotary drive means for imparting rotary motion to the seed feed wheels  38 , other rotary power means may be employed for the same purpose such as the aerator  25  or other ground engaging rotary device, and other rotary drive means may be employed such as belt and sheave drive extending between the ground engaging rotary device and the seed feed wheels. 
   As shown in  FIGS. 3-11 , the seed feed wheels  38  may be formed in pairs of segments such as segments  50  and  60 . The segments of each pair have the same diameter but have different sized seed detents so that segments of different sized detents can be matched together to dispense different sized seeds.  FIGS. 3-6  show one of the segments  50  of a seed feed wheel that has larger sized detents  58 . The rotary segment  50  with larger sized detents includes an annular bearing surface  52  and an adjacent annular detent surface  54 , both of which are coaxial with the non-circular drive shaft opening  56 . 
   The annular detent surface  54  includes an annular array of concave, radially outwardly facing detents  58 , with the detents being equally spaced about the perimeter of the segments, and the detents all being of the same size, both in depth and length. 
     FIGS. 7-10  illustrate the rotary segment  60  having smaller sized detents and that has an annular bearing surface  62  and an annular detent surface  64 , with both the annular bearing surface  62  and the annular detent surface  64  being coaxial with the drive shaft opening  66 . The annular detent surface  64  includes an annular array of concave, radially outwardly facing detents  68 . The construction of the small size rotary segment  60  and the large size rotary segment  50  are substantially the same, except for the sizes of the detents  58  and  68 . 
   As shown in  FIG. 11 , one of the large size rotary segments  50  is matched with one of the small size rotary segments  60  to make up one seed feed wheel  38 . The segments  50  and  60  are mounted coaxially on a drive shaft  70 . 
   As shown in  FIGS. 12 and 13 , the seed feed wheel segments  50  and  60  are mounted in abutment with each other on the drive shaft  70  and are telescopically fitted within the seed metering tube  30 . The detents of at least one of the seed feed wheel segment  50  or the seed feed wheel segment  60  are moved into registration with the seed entrance opening  34  and seed discharge opening  36  of the seed metering tube. 
     FIG. 14  illustrates the adjustment bracket  72  for the seed feed wheels  38  that functions as a feed wheel position adjustment means for moving the seed feed wheels  38  along the length of the seed metering tube  30 . The longitudinal movement of the seed feed wheels adjusts the amount of registration of the annular detent surfaces  54  and/or  64  that register with the entrance opening  34  and discharge opening  36  of the pairs of openings about the seed metering tube  30 . The feed wheel position adjustment bracket  72  includes an L-shaped bracket  74  that has one leg mounted to the frame of the apparatus and another leg that aligns the threaded screw  76  with the drive shaft  70  of the seed dispenser  24  through a nylon bearing  80 . Lock nuts  78  and  79  are used to engage the threads of the adjusting screw  76  on opposite sides of the bearing  80  of the bracket  74 . By repositioning the lock nuts along the length of the adjusting screw, the adjusting screw can move the drive shaft  70  with the seed feed wheels  38  axially through the seed metering tube  30 . This exposes more or less of the detents of the seed feed wheels, or exposes different detents of the seed feed wheels. 
   Typically, the seed feed wheels will be set up in accordance with size in anticipation of the types of seeds that are to be dispensed by the seeder.  FIG. 12  shows the set up for small seeds and  FIG. 13  shows the set up for large seeds. With this arrangement, when the first sized seed is to be dispensed, the appropriate sized seed feed wheel segment  50  will register with the seed entrance openings  34  and seed discharge openings  36  of the seed metering tube  30 . When the smaller sized seeds are to be dispensed from the hopper  22 , the lock nuts  78  and  79  of the adjustment bracket  72  are repositioned along the length of the threaded adjustment screw  76  to the extent necessary to make the proper repositioning of the seed feed wheel segments  50  and  60 . 
   It will be noted that the feed wheel segments  50  and  60  are oriented so that their annular detent surfaces  54  and  64  are juxtaposed each other, so that only a small amount of adjustment by the adjustment bracket  72  is required for changing the size of the annular array of concave radially outwardly facing detents  58  and  68 . 
   Further, the feed wheel segments  50  and  60  of the seed feed wheels  38  can be shifted longitudinally in the seed dispenser tube  30  so that portions of both of the detents of the feed wheel segments  50  and  60  can be exposed for fine adjustment of the quantity of seeds to be dispensed. 
   Although preferred embodiments of the invention have been disclosed in detail herein, it will be obvious to those skilled in the art that variations and modifications of the disclosed embodiments can be made without departing from the spirit and scope of the invention as set forth in the following claims.