Patent Publication Number: US-2021161062-A1

Title: Rotating ground driven high speed precision vacuum planter with seed injection teeth

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of and priority to U.S. Provisional Application No. 62/943,227, filed Dec. 3, 2019, which is hereby incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to agricultural equipment, and more specifically, to agricultural seed planters with planting wheels having a plurality of teeth arranged around the periphery of the planting wheels. 
     BACKGROUND 
     Ground engaging opener designs for the purpose of placing seed in the soil has remained largely unchanged for the past 50 years. The disk opener has been the prevailing design concept, both in single disk and double disk configurations where there is a rotating blade that runs through the soil at a slight angle to the direction of motion creating a furrow in which the seeds are deposited into. Prior to this design, the runner or shoe-type planter was the dominant design. With shoe-type planters, a stationary shoe would slide through the soil creating a furrow that the seeds into which would be placed. The disk opener was a significant advancement over the shoe planter because the disk opener can be made to operate while doing less tillage to the soil and can cut through plant residue in the field. The disk opener also takes far less pressure to push into the ground and can operate at higher speeds. 
     Over the last century, a continuous trend towards planting in field conditions with less tillage and soil preparation at ever higher speeds has emerged. Recently trends have seen the increased adoption of heavy cover crops into so-called “no till” planting systems. In these types of agronomic systems, very heavy cover crops are maintained in the field at planting time. These cover crops are beneficial because they prevent weed growth and increase the health of the soil. However, it is much more difficult to achieve a high degree of planter performance in systems where a very thick mat of plant material is present in the area where the cash crop seeds are being planted. This is because the thick mat of cover crop makes it difficult to achieve consistent seed depth and seed to soil contact, which are the most important drivers of the yield of the crop. The gauge wheel systems on vee opener type planters run on top of the mat of residue causing erratic seed depth, and the disk openers themselves have difficulty coping with cutting through the often still green plant material. 
     SUMMARY 
     To try to combat problems associated with minimal tilling and uneven or erratic seed depth, more and more automatic controls are added to conventional double disk type planters. These automatic controls can partially make up for the deficiencies of the fundamental planter design. Since vee opener double disk planters fundamentally are more effective where fields are primarily tilled before seeding, the automatic controls are more of a patchwork solution. Furthermore, as more and more complex automatic control is added to the planter, the planter becomes less friendly from an operation and service standpoint for a farmer. 
     Embodiments of the present disclosure provide a mechanical agricultural seed planter with a different design that does not have the fundamental problems associated with conventional planters. The agricultural seed planter combines functions of a seed meter and a ground opener, which can greatly increase speed of planting seeds in a field. The agricultural seed planter injects seed at consistent depths based on a depth to which each teeth of the agricultural seed planter punctures the soil. Importantly, the seed planter herein is completely and 100% green in that it uses absolutely no fossil fuel or electrical energy to operate and produces zero emissions and requires zero emissions to be moved across a field. In some implementations, it can be pulled or pushed manually by a human or animals along a field to be planted, without the aid of a tractor or other fuel-burning or battery-operated machine. In some implementations, there are no power sources such as batteries or fuel tanks or any other components that are powered by electricity or electrical energy of any kind. Because the seed planter can be moved entirely by humans or animals, no fossil-burning or battery-operated machines are required. This seed planter can be used on any field anywhere in the world, but in particular in areas where there is no easy access to fossil fuels, batteries, or a charging source. And yet the seed planter herein has a seed hopper or chamber that singulates seeds accurately one at a time into the ground at spaced distances and depths just as accurately as a tractor-pulled seed planter with electrically powered components, but without using any energy source except muscle power to move the planter across the field. If the field has a sufficient decline, gravity can be leveraged to move the seed planter in a downward direction along the field without expending human or animal energy. 
     According to some implementations of the present disclosure, an agricultural seed planter includes a plurality of mechanical modules arranged around a center to form a planting wheel, a frame coupled to the planting wheel, and at least one gauge wheel coupled to the frame. Each of the mechanical modules includes a tooth for injecting a seed into the soil. The tooth includes a hole axial to the length of the tooth. Each of the mechanical modules further includes a pressure generator coupled to the tooth and configured to generate positive or negative pressure to control a position of the seed when the seed is received by the tooth. 
     According to some implementations of the present disclosure, an agricultural planter includes a plurality of agricultural seed planters. A respective agricultural seed planter in the plurality of agricultural seed planters includes discrete teeth arranged on a periphery of the respective agricultural seed planter. Each of the discrete teeth has a hole axial to a length of the tooth for communicating fluid pressure through the tooth. 
     According to some implementations of the present disclosure, an agricultural seed planter that singulates seeds, one at a time, into the ground at a predetermined depth and can produce positive and negative air pressure from the traction force of pulling the planter across the ground. The positive and negative pressure can be produced by the compression or extension of a cylinder or bellow-like device. The cylinder or bellow device can be caused to extend and retract by a cam that actuates the device as the planter rotates. The negative pressure can be used to cause the seed to stick to a tooth against gravity, and the positive air pressure can be used to discharge or eject the seed from the tooth and at the same time prevent buildup of soil in the hole in the tooth through which the seed passes. A sensor can detect whether the seed mechanism has a seed or foreign object in the seed area of the tooth. The diameter of the wheel can change so as to alter the distance between the seeds and changes in the seed population. 
     According to some implementations of the present disclosure, a ground-driven seed planting device has discrete teeth around a periphery of a wheel. Each of the teeth includes an axial through-going hole to allow communication of fluid pressure to keep the seed from falling out or to discharge the seed into the soil. 
     According to some implementations of the present disclosure, a ground-driven seed planter is arranged in a wheel configuration, and the wheel has numerous similar modular elements allowing multiple configurations and sizes of the planter. 
     According to some implementations of the present disclosure, a ground-driven planter has teeth that push the seed into the ground and can move a component in and out that fills an area between adjacent teeth so as to form a continuous surface on the outside of the assembly comprising the tooth. The surface is continuous and smooth to allow a ground driver wheel to pass through a chamber containing a seed such that the only place the seed can go to escape the chamber is in a recess at the end of the tip of the tooth. A separate cam profile can cause the arm that fills the space between the tooth to move in and out. 
     According to some implementations of the present disclosure, a ground-driven planter with teeth around the periphery of a wheel includes one or more wheels in contact with the ground to control depth and/or to reduce the weight of the mechanism on the ground. 
     According to some implementations of the present disclosure, an agricultural planter includes multiple planter units, each one having a toothed wheel design and means of changing the seeding population by altering the distance between the rows. In other words, instead of adjusting the space between the seeds, which is typically fixed, by adjusting the distance between the rows, the seeding population density can be easily adjusted. 
     According to some implementations of the present disclosure, an agricultural planting system that changes the spacing between the rows to change the seed population rather than changing the distance between the teeth from which the seeds are discharged into the soil. In an aspect of the design according to the present disclosure, the space between the teeth is fixed and the seeds are discharged at a rate that is proportional to the rotational speed of the wheel. For soybean population, for example, two or three wheels can be linked close together with the teeth slightly offset from one another to have a relatively short distance between adjacent planting rows. The distance between the rows can be adjusted as the planter is moved through the field. According to another aspect, the spacing or distance between the teeth can be adjusted including in real time as the planter is moved across the field. In this aspect, the wheel includes a planar linkage folding mechanism that expands and contracts like a planar folding linkage first proposed by Chuck Hoberman. The linkage arms, which fold radially, are sized and spaced so that the distance between the teeth can be varied to accommodate different seed population requirements, which are well known to those familiar with the agricultural planting art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other advantages of the present disclosure will become apparent upon reading the following detailed description and upon reference to the drawings. 
         FIG. 1  illustrates a right side view of an agricultural seed planter, according to some implementations of the present disclosure; 
         FIG. 2  illustrates a left side view of the agricultural seed planter of  FIG. 1 , according to some implementations of the present disclosure; 
         FIG. 3  illustrates a front perspective view of components of the agricultural seed planter of  FIG. 1 , according to some implementations of the present disclosure; 
         FIG. 4  illustrates an exploded view of the components of the agricultural seed planter of  FIG. 1 , according to some implementations of the present disclosure; 
         FIG. 5  illustrates two mechanical modules coupled to cams, according to some implementations of the present disclosure; 
         FIG. 6  illustrates the two mechanical modules of  FIG. 5  in a first configuration, according to some implementations of the present disclosure; 
         FIG. 7  illustrates the mechanical modules of  FIG. 5  in a second configuration, according to some implementations of the present disclosure; 
         FIG. 8  illustrates the mechanical modules of  FIG. 5  in a third configuration, according to some implementations of the present disclosure; 
         FIG. 9  illustrates the mechanical modules of  FIG. 5  in a fourth configuration, according to some implementations of the present disclosure; 
         FIG. 10  illustrates a top perspective view of the agricultural seed planter of  FIG. 1 , according to some implementations of the present disclosure; and 
         FIG. 11  illustrates a tooth on a mechanical module, according to some implementations of the present disclosure. 
     
    
    
     While the present disclosure is susceptible to various modifications and alternative forms, specific implementations have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the present disclosure is not intended to be limited to the particular forms disclosed. Rather, the present disclosure is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims. 
     DETAILED DESCRIPTION 
     Embodiments of the present disclosure provide an agricultural planter that can be pulled along farmland by an individual. The planter can automatically plant seeds while being pulled along the farmland. The planter can be attached to an animal (e.g., an ox) or can be attached to a vehicle (e.g., a tractor). The planter can enable sustainable agriculture when an individual is pulling the planter long the farmland because, in some implementations, the planter operates without energy from burning fossil fuels or any other inputted energy apart from the pulling force from the individual. Although pulling is provided herein as an example, in some implementations, a pushing force can be applied to agricultural planters provided in the present disclosure. 
       FIG. 1  illustrates an average-sized human person  101  standing next to an agricultural seed planter  102 , according to some implementations of the present disclosure.  FIG. 1  illustrates a right side view of the agricultural seed planter  102 .  FIG. 2  illustrates a left side view of the agricultural seed planter  102 , according to some implementations of the present disclosure. The following discussion refers to numbered elements in  FIGS. 1 and 2 . The terms “left side view” and “right side view” are merely used as examples relative to a direction of motion of the agricultural seed planter  102 . Although the height of the agricultural seed planter  102  is depicted as being larger than the height of the person  101 , in some implementations, both heights are substantially the same or the person  101  is taller than the agricultural seed planter  102 . The person  101  and the agricultural seed planter  102  are positioned on soil  104 . In some implementations, the overall height of the seed planter  102  can range from about 36 inches to about 96 inches. 
     The agricultural seed planter  102  includes a planting wheel  116 , a seed chamber or hopper  106 , a frame  114 , and in some implementations, a handle  111  coupled to the frame  114 . The handle  111  includes a structural member  112  that couples to the frame  114  and an ergonomic interface  110  that allows the person  101  to pull the agricultural seed planter  102 . In some implementations, the ergonomic interface  110  can facilitate connecting the agricultural seed planer  102  to a vehicle or an animal. The seed chamber  106  is also coupled to the frame  114  so that as the agricultural seed planter  102  moves, the seed chamber  106  remains in the same position relative to the position of the frame  114 . 
     In some implementations, the frame  114  is coupled to one or more gauge wheels  108 .  FIG. 1  shows two gauge wheels  108 , a front gauge wheel closer to the person  101  and a rear gauge wheel farther from the person  101 . The gauge wheels  108  can be off-center from the planting wheel  116  such that the gauge wheels  108  are not directly in front of the planting wheel  116 . This arrangement can be beneficial in the situation where there is only one gauge wheel. In such a situation, the agricultural seed planter  102  still has at least two contact points to the soil  104 , enhancing stability of the agricultural seed planter  102 . Having two or more contact points to the soil  104  spreads the weight of the agricultural seed planter  102  across the multiple contact points so that the weight of the planting wheel  116  on the soil  104  is reduced at the locations where the planting wheel  116  makes contact with the soil  104 . For example, the gauge wheels  108  contact the soil  104 , taking off some of the load of the planting wheel  116  on the soil  104 . The planting wheel  116  contacts the soil  104  as well, thus, the distributed weight of the planting wheel  116  is shared between the gauge wheels  108  and the planting wheel  116 . 
     The planting wheel  116  includes a plurality of fingers or teeth  120  spaced around a periphery of the planting wheel  116 . The teeth  120  are configured to deposit seed in the soil  104  as the planting wheel  116  rotates or travels in a forward motion along the soil  104 . In some implementations, the teeth  120  are positioned so as to achieve an optimal spacing of seeds, thus, depending on a desired spacing, the location of the teeth  120  can be adjusted, thus affecting a diameter of the planting wheel  116 . The diameter of the planting wheel can range from 36 inches to 96 inches, for example. In some implementations, a smaller diameter planting wheel  116  injects seed with larger separation than a larger diameter planting wheel  116 . The planting wheel  116  can include a plurality of pressure generators coupled to the teeth  120 . The pressure generators can be cylinders or bellow devices. As examples, two bellow devices  130  are provided in  FIGS. 1 and 2  to illustrate a coupling of the bellow devices  130  to teeth  120 . For clarity, bellow devices are coupled to each of the teeth  120  in  FIGS. 1 and 2 , but are not shown for all the teeth  120 . The gauge wheels  108  elevate the frame  114  such that a depth of seed injection into the soil is based at least in part on the elevated distance of the frame  114 . 
     While the spacing or distance between the teeth  120  are shown as being fixed, in some implementations, the spacing or distance can be expanded or contracted in real time as the planter  102  is moved across the field. In such implementations, the wheel  116  includes a planar linkage folding mechanism that expands and contracts like a planar folding linkage first proposed by Chuck Hoberman. The linkage arms which fold radially are sized and spaced so that the distance between the teeth can be varied to accommodate different seed population requirements, which are well known to those familiar with the agricultural planting art. An example of constructing a radially foldable planar linkage can be seen in www.sciencedirect.com/science/article/pii/S0020768307000923, whose contents are incorporated herein in their entirety. It will be appreciated that these concepts are already known to the skilled person, so the citation to this article is only to demonstrate awareness in the art as to how to implement the mechanism and applying it to the wheel  116  in the present disclosure. 
       FIG. 3  illustrates a front perspective view of components of the agricultural seed planter  102 , according to some implementations of the present disclosure.  FIG. 4  illustrates an exploded view of the components of the agricultural seed planter  102 , according to some implementations of the present disclosure. A brief description of the operation of the agricultural seed planter  102  ( FIGS. 1 and 2 ) will be provided using components labeled in  FIGS. 1-4 . Briefly, the planting wheel  116  ( FIG. 1 ) rotates toward the person  101 . As the planting wheel  116  rotates, the teeth portions interfacing with the soil  104  deposit seed into the soil  104 . For example, the tooth  120   c  is moving toward the soil  104  to deposit a seed in the soil  104 , and the tooth  120   d  is moving away from the soil after depositing a seed in the soil  104 . The tooth  120   d  is moving toward the seed chamber  106  to collect another seed. The tooth  120   b  is depicted as being within the seed chamber  106 , and further rotation of the planting wheel  116  will move the tooth  120   b  out of the seed chamber  106 . The tooth  120   a  is depicted as being outside the seed chamber  106  after exiting the seed chamber  106 . 
     Between each of the teeth  120  there is a retractable tooth filler  118 . The retractable tooth filler  118  fills the gap between the teeth  120  so that there is a smooth continuous surface present when the teeth  120  pass through the seed chamber  106  as the planting wheel  116  rotates. For example, the tooth fillers  118   a  and  118   b  are flush with the tooth  120   a . The tooth filler  118   c  is shown to be retracting from the tooth  120   c  as the tooth  120   c  is moving towards the soil  104 . Similarly, the tooth filler  118   d  is shown to be extending towards the periphery of the planting wheel  116  to create a smooth surface for adjacent teeth  120  prior to the adjacent teeth  120  entering the seed chamber  106 . The seed chamber  106  includes guides  122  such that the tooth fillers  118  and the teeth  120  are positioned between the guides  122  when passing through the seed chamber  106 . The guides  122  essentially create a track for the teeth  120  and tooth fillers  118  to follow. At any given point, while the planting wheel  116  is in operation, some tooth fillers  118  will be fully extended toward adjacent teeth  120 , some tooth fillers  118  will be fully retracted from adjacent teeth  120 , and some tooth fillers  118  will be in the process of being extended toward or retracted from adjacent teeth  120 . Tooth fillers adjacent to teeth  120  in the seed chamber are fully extended, and tooth fillers adjacent to teeth  120  interfacing the soil  104  are fully retracted. 
     Referring to  FIG. 3 , the plurality of teeth  120  are located on a sagittal plane of the planting wheel  116 . Each tooth filler  118  that is extended to form the smooth surface is extended from a left side and from a right side. For example, the tooth filler  118   a  is extended from the right side to the sagittal plane, and the tooth filler  118   b  is extended from the left side to the sagittal plane, such that when the tooth  120   a  is within the seed chamber  106 , the tooth fillers  118   a ,  118   b  and the tooth  120   a  are positioned in the sagittal plane with the tooth fillers  118   a  and  118   b  flush against the tooth  120   a.    
     In some implementations, the rear gauge wheel  108  of the two gauge wheels  108  (shown in  FIG. 1 ) acts as a closing wheel, pushing soil down over the top of the seed that has been placed in the indentation made by the teeth  120 . In some implementations, the front gauge wheel  108  (shown in  FIG. 1 ) acts as a cover crop crimper. The front gauge wheel  108  can run over or crimp crops or weeds to prepare a portion of the soil  104  right before planting a seed in the area. Attaching the planting wheel  116  to the frame  114  allows vertical movement of the planting wheel  116  over the contour of the soil  104 . 
     In some implementations, the planting wheel  116  is composed of multiple mechanical modules (e.g., mechanical modules  416 ,  418  of  FIG. 4 ). Referring to  FIGS. 1 and 2 , The mechanical modules are rigidly connected to a plate  124  at connection points (e.g., connection point  126 ). The planting wheel  116  rotates about a center  128 . A single connection point rigidly connects two mechanical modules to the plate  124 .  FIG. 4  illustrates an exploded view of the agricultural seed planter  102  showing additional components, according to some implementations of the present disclosure. The frame  114  includes a frame attachment arm  402 . The frame attachment arm  402  is connected to a hub  404 . The hub  404  allows mounting of the planting wheel  116  ( FIG. 3 ) to the frame  114 . 
     A set of cams  406 ,  408  and  410  are provided in the agricultural seed planter  102 . A first set of cams  406  and  410  control bellow devices (e.g., the bellow device  130  of  FIG. 1 ) provided in the planting wheel  116 , and a second set of cams  408  control extending and retracting the tooth fillers  118  ( FIG. 3 ) of the planting wheel  116 . The set of cams  406 ,  408 , and  410  are rigidly connected to the hub  404  such that the set of cams  406 ,  408 , and  410  do not rotate while the planting wheel  116  rotates. An axle  412  that attaches to the plate  124  and connects to the frame attachment arm  402  freely rotates. The planting wheel  116  rotates, the plate  124  rotates, and the axle  412  rotates while the frame  114  is moved along the soil  104 . The cams  406 ,  408 , and  410  remain stationary with respect to the frame  114  and do not rotate. The cam  408  (the tooth fillers cam) connects to the hub  404 , and the cams  406  and  410  (bellow device cams) attach to the cam  408 . 
       FIG. 5  illustrates two mechanical modules  416  and  418  coupled to the set of cams  406 ,  408 , and  410 , according to some implementations of the present disclosure.  FIG. 6  illustrates a zoomed in version of the two mechanical modules  416  and  418  in a first configuration relative to the set of cams  406 ,  408 , and  410 , according to some implementations of the present disclosure. Components associated with the mechanical module  416  are labeled with “j” and components associated with the mechanical module  418  are labeled with “h”. The mechanical module  416  includes a rigid member  624   j , and the mechanical module  418  includes a rigid member  624   h . The rigid member  624   j  and the rigid member  624   h  are linked together at hollow portions  620   j  and  620   h . The hollow portions  620   j  and  620   h  not only allow linking together the mechanical modules  416  and  418 , but also allow liking both mechanical modules  416  and  418  to the plate  124  ( FIG. 1 ), at for example, the connection point  126 . Every two mechanical modules share a same connection point to the plate  124  ( FIG. 1 ). 
     The mechanical modules  416  and  418  have bellow devices  130   j  and  130   h , respectively, that are coupled to the teeth  120   j  and  120   h , respectively. The bellow device  130   j  is controlled by the mechanical module  418 , and the bellow device  130   h  is controlled by an adjacent mechanical module that is not shown. The mechanical module  416  controls an adjacent bellow device that is not shown. 
     The mechanical module  418  includes a tooth filler  118   h  that is shown in a retracted position in  FIG. 6 . The tooth filler  118   h  is connected to the rigid member  624   h  by a linkage that allows the tooth filler  118   h  to be retracted out of the way during the planting wheel  116  ( FIG. 1 ) rotating when the tooth  120   h  is in the area of the soil  104  ( FIG. 1 ). This linkage is connected to a push rod  612   h  that is connected at the other end to another link arm  614   h . The link arm  614   h  is a tooth filler actuator link that minimizes amount of side load applied to the push rod  612   h  as the planting wheel  116  ( FIG. 1 ) rotates. The link arm  614   h  has at one end a roller or follower device  607   h  and at the other end a pivot point  605   h . As the planting wheel  116  ( FIG. 1 ) rotates, the follower device  607   h  rolls against the cam  408 , resulting in an actuation of the tooth filler  118   h . The cam is designed to retract the tooth filler  118   h  out of the way as the tooth  120   h  enters the soil  104  ( FIG. 1 ) and to cause the tooth filler  118  to extend before the tooth  120   h  enters the seed chamber  106  ( FIG. 1 ). In some implementations, the link arm  614   h  is biased against the cam  408  with spring pressure. An example of a spring  622  is provided in  FIG. 6 . 
     In some implementations, the bellow devices  130   h  and  130   j  are positioned concentric with the teeth  120   h  and  120   j , respectively. The bellow devices  130   h  and  130   j  allows transmission of positive or negative air pressure to the teeth  120   h  and  120   j . For simplicity and clarity in description, the bellow device  130   j  is referred to here, but a similar description can be provided for the bellow device  130   h . The bellow device  130   j  on one end is connected to the tooth  120   j . The interface  606  provides a structure for the bellow device  130   j  to be secured to the rigid member  624   j  such that the positive or negative air pressure can be communicated to the tooth  120   j . The rigid member  624   j  includes a curved member  604   j  and a portion  602   j  for interlocking with an adjacent mechanical module (not shown). 
     The bellow device  130   j  is controlled by the mechanical module  418 . The bellow device  130   j  is connected to a bellow actuation linkage  616   h . The linkage  616   h  allows the bellow device  130   j  to be compressed and decompressed with approximately linear motion. A flat portion  618   h  connected to the linkage  616   h  compresses and decompresses the bellow device  130   j , preventing the bellow device  130   j  from pinching. The linkage  616   h  pivots about the rigid member  624   h  at pivot points  615   h . Although the linkage  616   h  includes two different arms with two pivot points  615   h , in some implementations, the linkage  616   h  can include one or more pivot points  615  with one or more respective arms. In some implementations, an air cylinder can be used in place of the bellow device  130   j . The bellow actuation linkage  616   h  is connected to an actuation rod  608   h , which is then connected to another actuation link  610   h . The actuation link  610   h  includes a roller follower device  611   h  at one end and the other end having a pivot point  609   h . This follower device  611   h  rolls against the cam  410 . 
     As the planting wheel  116  ( FIG. 1 ) rotates the cam  410  causes the bellow device  130   h  to begin retracting and causing air to be sucked into the tooth  120   j , right as the tooth  120   j  is entering the seed chamber  106  ( FIG. 1 ). The bellow device  130   j  continues to retract aggressively as the tooth  120   j  passes through the seed chamber  106  ( FIG. 1 ), causing a seed to get sucked onto the tooth  120   j . As the tooth  120   j  passes out of the seed chamber  106  ( FIG. 1 ) the bellow device  130   j  continues to retract at a slower rate so as to hold the seed in the end of the tooth  120   j.    
     The continuous negative pressure from the bellow device  130   j  continues until the tooth  120   j  is just about to reach the maximum bottom point where the tooth  120   j  is deepest in the soil  104  ( FIG. 1 ). The negative pressure keeps the seed from falling out of the tooth  120   j  due to gravity as the wheel  116  is turning. At this point a sharp change in curvature of the cam  410  causes the bellow device  130   j  to compress rapidly. Compressing the bellow device  130   j  generates positive air pressure that releases or ejects the seed into the soil at approximately bottom dead center and prevents soil buildup on the tooth  120   j . The bellow device  130   j  then continues to be compressed at a slower rate to maintain airflow out of the tooth  120   j  as the tooth  120   j  exits the soil  104 . The maintained airflow out of the tooth  120   j  prevents soil buildup or prevents soil from becoming packed into the end of the tooth  120   j . The idea here is that continuous negative pressure holds the seed in place once it has left the seed chamber in opposition to gravity and centrifugal forces that want to dislodge the seed from the tooth until the seed is in position at approximately bottom dead center relative to earth to be discharged into the soil, at which the positive pressure is automatically employed to eject the seed at a depth into the soil. 
     The curved member  604   j  provides a larger surface area compared to the tooth  120   j  so that in some implementations, the curved member  604   j  rests upon the soil  104  ( FIG. 1 ) or contours the field while the tooth  120   j  is in soil  104 . For example, in  FIG. 1 , two bottom-most teeth (not shown) are not visible because the teeth are within the soil  104 . The two bottom-most teeth may not be visible, but the circular shape of the planting wheel  116  is visible because curved members (e.g., the curved member  604   j ) contour surface of the soil  104  when in contact with the soil  104 . 
     The mechanical module  416  has similar components to the mechanical module  418 . In some implementations, the mechanical module  418  is substantially a mirror image of the mechanical module  416  when viewed from the sagittal plane of the planting wheel  116 . Both the mechanical modules  416  and  418  share the same cam  408  for actuating tooth fillers  118   h  and  118   j  (see  FIG. 7 ). The mechanical module  418  uses the cam  410  for actuating the neighboring bellow device  130   j , and the mechanical module  416  uses the cam  406  for actuating a neighboring bellow device which is not shown. The linkage  616   j , the flat portion  618   j  of the linkage  616   j , etc., perform similar functions as those described for the linkage  616   h , the flat portion  618   h  of the linkage  616   h , etc. Using the directional convention of  FIGS. 1-3 , the mechanical module  418  is on the right side of the sagittal plane of the planting wheel  116 , and the mechanical module  416  is on the left side of the sagittal plane of the planting wheel  116 . That is, the mechanical module  416  is positioned closer to the frame  114  ( FIG. 1 ) when compared to the mechanical module  418 . 
       FIG. 6  illustrates the two mechanical modules  416  and  418  and the cams  406 ,  408 , and  410  in the first configuration. In some implementations, the first configuration denotes a full retraction or close to a full retraction the bellow devices  130   h  and  130   j . That is, the teeth  120   h  and  120   j  are ready or close to being ready to inject seed into the soil  104 . The teeth  120   h  and  120   j  are likely within the soil  104  for the seed injection. 
       FIG. 7  illustrates the mechanical modules  416  and  418  in a second configuration, according to some implementations of the present disclosure. In some implementations, the second configuration denotes a full compression or near full compression of the bellow devices  130   h  and  130   j . The tooth fillers  118   h  and  118   j  are fully extended. In some implementations, the second configuration indicates that the teeth  120   h  and  120   j  are close to being received in the seed chamber  106  ( FIG. 1 ). 
       FIG. 8  illustrates the mechanical modules  416  and  418  in a third configuration, according to some implementations of the present disclosure. The third configuration indicates an intermediate position of the bellow devices  130   h  and  130   j . The third configuration can indicate that the bellow devices  130   h  and  130   j  are being retracted to maintain a negative pressure that holds seeds in the teeth  120   h  and  120   j  in place. The tooth fillers  118   h  and  118   j  are fully extended. The third configuration indicates that the teeth  120   h  and  120   j  can be within the seed chamber  106  ( FIG. 1 ), about in a similar position as the position where the tooth  120   a  is depicted in  FIG. 1 , or another position prior to the position where the tooth  120   c  is depicted in  FIG. 1 . 
       FIG. 9  illustrates the mechanical modules  416  and  418  in a fourth configuration, according to some implementations of the present disclosure. The fourth configuration indicates an intermediate position of the bellow devices  130   h  and  130   j . Since the tooth fillers  118   h  and  118   j  are retracted, the fourth configuration can indicate that the teeth  120   h  and  120   j  are in a position similar to the position of the tooth  120   d  depicted in  FIG. 1 . 
     Referring back to  FIG. 1 , the bellow devices  130  allow providing either a positive or a negative air pressure communicated through the teeth  120 . The cycle where positive air pressure is provided is shorter than the cycle where negative air pressure is provided. For example, for a respective tooth  120 , negative air pressure is communicated through the tooth from right before the tooth enters the seed chamber  106  until right before the tooth is in position to inject the seed into the soil  104 . In the indicated positions on  FIG. 1 , the teeth  120   a ,  120   b  and  120   c  all communicate negative air pressure to keep seed in place. The negative air pressure produces a vacuum suction that keeps the seed in place relative to the tooth  120 . The tooth  120   d  communicates positive air pressure while its respective bellow device  130  is being compressed in preparation for entering the seed chamber  106 . 
     Therefore, the cams  410  and  406  have irregular shapes (e.g., ovoid) and are not circular. The cams  410  and  406  provide a show retraction of bellow devices  130  to maintain the negative air pressure for a longer time period when compared to the positive air pressure. The positive air pressure is used to inject seed into the soil  104  and also prevent soil buildup while the teeth  120  leaves the soil  104 . The air being released from the teeth  120  prevent soil from building up at the tips of the teeth  120 . In some implementations, a series of brushes can be positioned to clean soil off of the teeth before entering the seed chamber  106 . In some implementations, the series of brushes can be driven so that the brushes rotate so enhance cleaning the teeth  120  before the teeth  120  enter into the seed chamber. 
       FIG. 10  illustrates a top perspective view of the agricultural seed planter  102  of  FIG. 1 , according to some implementations of the present disclosure.  FIG. 10  provides a view of the inside of the seed chamber  106 . The tooth fillers  118  provide a smooth continuous outer surface about the periphery of the planting wheel so that as the teeth  120  pass through the seed chamber  106 , only positions available for seed to be captured are at the teeth  120 . There is only one seed per tooth at a time. Negative air pressure being communicated through the teeth  120  in the seed chamber  106  attract seed and hold attracted seed to the teeth  120  until the attracted teeth is injected in the soil  104  ( FIG. 1 ). In some implementations, a series of fingers, bars, or brushes can be provided proximate to the seed chamber  106  as the teeth  120  exit the seed chamber  106 . The series of fingers, bars, or brushes can knock extra seeds off a tooth, should more than one seed become attached to the tooth. 
       FIG. 11  illustrates a tooth  120  on a mechanical module  1100 , according to some implementations of the present disclosure. The mechanical module  1100  is similar to or the same as the mechanical modules  416  and  418  of  FIGS. 6-9 . The tooth  120  has a small dimple  1102  (or recess) and an even smaller hole  1104  passing through the entire length of the tooth  120 . The dimple  1102  provides a place for the seed to sit in, and the small hole  1104  allows positive or negative air pressure to be transmitted to the seed. The seed sticks to the tooth  120  because of the negative air pressure. In some implementations, the dimple  1102  is deeper than a size of the seed such that the seed is not directly compressed when the tooth  120  interfaces with the soil  104  ( FIG. 1 ). Avoiding direct compression can reduce risk of mechanical damage to the seed as the seed is being pushed into the ground. The planting wheel  116  is formed by linking multiple mechanical modules  1100  together. In some implementations, a sensor (not shown) is coupled to each of the mechanical modules of the planting wheel  116  to determine whether the tooth of each module includes a seed. The sensor can be powered by electrical energy that is harvested from the rotation of the wheel using a dynamo generator or the like having a commutator that turns with the rotation of the wheel so that no battery or other electrical power source is required to power the sensor or any other electrical component, such as an LED light, on the seed planter  102 . 
     Although the tooth  120  as depicted in various implementations is shown to extend orthogonally from the periphery of the planting wheel  116 . In some implementations, the tooth  120  can be provided at an angle such that a radial line drawn from the center  128  ( FIG. 1 ) of the planting wheel  116  to the tooth  120  intersects a major axis of the tooth at an angle. 
     Although only one agricultural seed planter is discussed herein, two or more agricultural seed planters can be joined together in parallel to plant seeds in rows. For example, the ergonomic interface of two or more agricultural seed planters can be linked together so that the different agricultural seed planters can be pulled or driven in unison to plant seeds in parallel. For example, two or three or four or five or six or seven or eight or nine or ten or eleven or twelve or thirteen or fourteen or fifteen or sixteen or seventeen or eighteen or nineteen or twenty seed planters can be linked together and moved together as a single unit to seed the same number of rows. As the number of planters increases, the moving force will increase but not linearly with each additional planter. While one or two planters can be moved by a single human, for example, when a larger number of planters are linked together, one or more draft horses or similar animals can be employed to move all of the planters down the rows on a field. 
     Embodiments of the present disclosure provide a purely mechanical agricultural seed planter. The mechanical agricultural seed planter has a built-in seed meter. That is, seed is injected based on separation between the teeth, and each teeth punctures the soil to a specific depth thus reducing erratic seed depths between adjacently planted seeds. The teeth allow seed to be injected into the soil without having to till the soil. Thus, the agricultural seed planter combines both functions of opening space for seed to be injected into the ground and also a spacing for seeds being planted. Thus, the agricultural seed planter itself is a seed meter. Conventional planters, on the other hand, have opener devices that are separate from meter devices. 
     A reason why a combined opener device-seed meter functionality is valuable is because one of the hardest problems to solve is how to get seed onto the end of a planter&#39;s tooth at high speed. Most farmers will not want to plant slower than 5 miles per hour. In recent years, the trend is to plant at higher and higher speeds, so as to plant as much of the crop as possible in as small of a window as possible when soil conditions are optimal. The beauty of making the entire opener device act as the seed meter is that having a large diameter slows down angular velocity of the individual teeth as the seed gets sucked onto the individual teeth. The slower angular velocity makes it easier to get the seed onto the end of the tooth. By being purely mechanical, agricultural seed planters, in some embodiments, free farmers of the burden of having to try to maintain the operation of complex electronic and hydraulic systems. Furthermore, a modular design of agricultural seed planters as provided herein are easier to service. 
     One or more elements or aspects or steps, or any portion(s) thereof, from one or more of any of claims  1 - 20  below can be combined with one or more elements or aspects or steps, or any portion(s) thereof, from one or more of any of the other claims  1 - 20  or combinations thereof, to form one or more additional implementations and/or claims of the present disclosure. 
     While the present disclosure has been described with reference to one or more particular embodiments or implementations, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present disclosure. Each of these implementations and obvious variations thereof is contemplated as falling within the spirit and scope of the present disclosure. It is also contemplated that additional implementations according to aspects of the present disclosure may combine any number of features from any of the implementations described herein.