Patent Publication Number: US-2021161063-A1

Title: Trailing arm device and assembly with parallel linkage

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. Non-Provisional application No. 15/415,755 filed 25 Jan. 2017, now U.S. Pat. No. 10,798,870, issued 13 Oct. 2020, entitled “Trailing Arm Device and Assembly with Parallel Linkage,” which claims priority to U.S. Provisional Application No. 62/286,906 filed 25 Jan. 2016 entitled “Trailing Arm Device and Assembly With Parallel Linkage,” and U.S. Provisional Application No. 62/326,489 filed 22 Apr. 2016 entitled “Trailing Arm Device and Assembly With Parallel Linkage,” and U.S. Provisional Application No. 62/395,265 filed 15 Sep. 2016 entitled “Trailing Arm Device and Assembly With Parallel Linkage,” each of which is hereby incorporated by reference herein in their respective entireties. 
    
    
     TECHNICAL FIELD 
     The technical field relates to agricultural seed planters and drills. More specifically, the technical field relates to parallel linkage-connecting mechanisms between opening assemblies and closing assemblies on planters and drills. 
     BACKGROUND 
     Agricultural seed planting is typically accomplished by multi-row planters. Each planter may include multiple row units adapted for opening a seed furrow, depositing seeds within the furrow, and closing the seed furrow around the seeds. In some cases, each row unit of the planter may also open a fertilizer furrow adjacent to each seed furrow, deposit liquid fertilizer in each fertilizer furrow, and close each fertilizer furrow. 
     Some planters are equipped or retrofitted to be equipped with fertilizer depositing equipment (e.g., fertilizer furrow opener discs and fertilizer deposit tubes) located on a leading or front side of the planter. Planters so configured can have problems in fields with moist or wet soil. Specifically, disturbing the soil with the fertilizer equipment located in front of the planter gauge wheels can cause the moist or wet soil to accumulate on the gauge wheels. The soil accumulation increases the effective diameters of the gauge wheels and causes the planter to run too shallow with respect to the depositing of the seed in the seed furrows. 
     Planters are increasingly used in no-till situations, resulting in the planter traversing fields with substantial deviation in the field surface and a substantial amount of obstructions (e.g., debris, clods, stubble, old furrows, etc.). Furthermore, in certain Midwest farm areas, ditches must be plowed in fields between planting seasons to facilitate the drainage of spring showers from the fields. Most planters have proven ineffective in such rough field surface conditions. It is not unusual for the use of planters in rough field conditions to result in seed depths that radically range between too deep and too shallow. Also, it is not unusual for the use of planters in such field conditions to result in the planter components being damaged. 
     Traditional closing assemblies use standard swing arm tail sections, which can be found on many of the planters built today. But, these swing arm tail sections have a limited amount of travel up and down (roughly 4″) throughout full movement when planting. These tail sections are limited when there are ditches to cross or terraces to plant over, as the amount of travel is limited to 2″ both ways of center. Sometimes this isn&#39;t enough as it gives poor seed to soil contact by not closing the seed V properly or leaving seeds on top of the ground. Whenever the press wheels flex up the contact points on the press wheels get wider causing them to be toe out and they tend to over cover the width of the seed V. When the press wheels go down past center they under cover resulting in toe in, which causes the seed V to not close properly. Also when the wheels max out, the wheels on the top side can raise the planter unit out of the ground causing seed depth to change. By running extra spring pressure on the press wheels you create up pressure on the row units. Thus, swing arm tail sections have severe limitations. Furthermore, as the planter travels through the field at speeds above 5 MPH the swing arm closing systems are constantly moving or vibrating up and down along the planter unit itself causing uneven depth control. Also when planting up and over terraces, there are areas over the top of the terrace cause the double discs of the planter to lift out of the ground (planting the seeds on top of the ground). Or, in some instances cause the press wheels to carry the weight of whole planter on one side or other of the terrace, and then on the opposite side of the terrace, the double discs openers are totally bottomed out for depth and the press wheels are off the ground not closing the furrow. This leaves several feet of seeded area across a ditch or terrace that is blanked out due to poor seed to soil contact. 
     There is a need in the art for a planter capable of providing liquid fertilizer in rough fields without adverse impact on seed depth and damage to planter components. There is also a need in the art for a planter capable of maintaining a parallel relationship to the field with adequate but separate pressure adjustments between opener assemblies and closer assemblies. 
     A press wheel or firmer wheel is a wheel attachment on an agricultural unit for compacting the soil in the seeded furrows after the soil has been planted and, in some instances, after a closing wheel has deposited loose soil overtop of the seed. Traditional press wheels are frequently rubberized tires that are pulled across a furrow. This type of press wheel tire tends to smear the soil over the area on which they press. In response to a hot, windy day, the soil will crack and become like concrete over the seed trench area. 
     The use of press wheels on planters to compact soil around and over seeds deposited in the bottom of a seed furrow has been practiced for many years. The purpose of compacting the soil is to promote seed germination by minimizing air pockets, thus improving the capillary action of the moisture in the soil as well as reducing wind erosion of the soil over the seed. Traditional press wheels compress and mold the bottom of the furrow to establish an environment conducive to good germination, but they tend to displace the soil away from the furrow by smashing it with portions other than the tread of the wheel. Forcing the soil in undesired directions may result in soil conditions conducive to drying and cracking. 
     Some traditional press wheels, particularly in dry soil conditions, cause the sides of the furrow to cave in as the press wheels pass and the seeds are then covered by random depths of the soil. Movement of the press wheels through the furrow actually promotes collapse of the furrow sides. The sides of the furrows have little resistance to being washed in the first time it rains. The loosened condition of the sides of the furrows provides little resistance to wind erosion as well as to erosion from rain. 
     Some traditional wheels do not even compress over the top of the furrow but instead work the sides of the furrow again, leaving undesirable conditions on the top of the furrow. These wheels also may form rooster tails, kicking up dirt in random directions and leaving it uncompressed. 
     Another problem is that to avoid plugging of the press wheels. For heavy liquid fertilizers, it has been found that the liquid dispensing device in some instances functions most efficiently if the liquid fertilizer is diluted so that the fertilizer flows evenly and without plugging. However, the greater volume of liquid in the furrow additionally produces wetness in the furrow that can cause the press wheels to build up with mud, which, in turn, leads to closing problems with the press wheels. 
     SUMMARY 
     In one embodiment of an agriculture planter, the planter may include a planter frame, a seed hopper and a trailing arm assembly. The planter frame may include a hitch tongue extending forward from the planter frame. The trailing arm assembly may be coupled to a rear portion of the planter frame via a parallel linkage and extend rearward from the planter frame, and include separate, but adjustable, trailing arm assemblies for the opening implements and the closing implements. 
     In accordance with various embodiments, a trailing arm assembly may include a frame bracket attachable to a planter towing frame, a first frame, and a parallel linkage connecting the frame bracket and the first frame with a first pivot and a second pivot on the frame bracket and a first pivot and a second pivot on the first frame. The trailing arm assembly may also include an adjustable biasing member extending from the parallel linkage to the frame bracket. The parallel linkage may be connected between the first frame and the frame bracket such that the parallel linkage maintains a parallel orientation of the first frame. The orientation may be orthogonal to the resultant downward force Fl exerted by the adjustable biasing member on the parallel linkage. The adjustable biasing member is adjustably connected to a portion of the parallel linkage and adjustably engages a plurality of detents formed in the portion of the parallel linkage, wherein the adjustable biasing member is attached to the first frame below at least one pivot of the parallel linkage. The parallel linkage may be a four bar parallel linkage having an upper set of links and a lower set of links. The upper set of links in the four bar parallel linkage may be cross-braced with one or more plates forming a continuous frame between a first side and a second side of the upper link. The lower set of links in the four bar parallel linkage may be cross-braced with one or more plates forming a continuous frame between a first side and a second side of the lower link. 
     In accordance with various embodiments, the first frame forms a portion of an opener assembly including an opener disk and a gauge wheel. The first frame includes an adjustment mechanism operable to change the position of the gauge wheels relative to the first frame. The trailing arm assembly may include a second frame. The second frame may be a closer assembly frame having one or more closing wheels. The first frame and the second frame may be connected to one another such that they operatively move independently with respect to each other in the vertical direction and the second frame is connected to the first frame via a second parallel linkage. The second parallel linkage may be a four bar parallel linkage having a pair of upper links and a pair of lower links. The upper set of links in the four bar parallel linkage may be fixedly connected to one another by a plate. The second parallel linkage may include a second biasing member. The second biasing member may be adjustable. 
     In accordance with various embodiments, an adjustment lever may be connected to a first end of the biasing member with the second end of the biasing member connected to the first frame. Movement of the adjustment handle in a first direction causes the force from the biasing member to increase and movement of the adjustment handle in the opposite direction causes the force from the biasing member to decrease. The upper set of links in the four bar parallel linkage may be connected via a plate having an aperture defined therein with the aperture forming a plurality of separate detents which hold the adjustment lever movably in place, while allowing that the adjustment lever to be adjustable between the separate detents. The trailing assembly may include one or more gauge wheels adjustably connected to the first frame and connected to an adjustment handle such that movement of the adjustment handle changes the vertical relationship between the one or more gauge wheels and the first frame. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of an agriculture tractor pulling an agriculture planter towing a liquid fertilizer tank trailer. 
         FIG. 2  is a top-rear isometric view of the planter. 
         FIG. 3  is a top-rear isometric view of a trailing arm assembly forming part of the planter. 
         FIG. 4  is a top-rear isometric view of a closer trailing arm assembly forming a part of the trailing arm assembly of  FIG. 3 . 
         FIG. 5A  is a side view of a trailing arm assembly forming part of the planter. 
         FIG. 5B  is a side view of a closer trailing arm assembly forming a part of the trailing arm assembly of  FIG. 5A . 
         FIG. 5C  is a side view of a trailing arm assembly forming part of the planter with the closer trailing arm assembly in an articulated position relative to the position shown in  FIG. 5A . 
         FIG. 5D  is a side view of a closer trailing arm assembly forming a part of the trailing arm assembly of  FIG. 5C . 
         FIG. 6A  is a top-rear isometric view of a trailing arm assembly forming part of the planter having a fertilizer disc and a fertilizer distribution system. 
         FIG. 6B  is a side view of a trailing arm assembly forming part of the planter having a fertilizer disc and a fertilizer distribution system. 
         FIG. 6C  is a side view of a trailing arm assembly forming part of the planter with the closer trailing arm assembly in an articulated position relative to the position shown in  FIG. 6B . 
         FIG. 7A  is a top-rear isometric view of a trailing arm assembly forming part of the planter having a fertilizer disc. 
         FIG. 7B  is a side view of a trailing arm assembly forming part of the planter having a fertilizer disc. 
         FIG. 8  is a top-rear isometric view of a trailing arm assembly forming part of the planter having an alternate style of closer wheel. 
         FIG. 9  is a top-rear isometric view of a trailing arm assembly forming part of the planter having closer wheel connected to a walking arm. 
         FIG. 10A  is a side plane view of a trailing arm assembly forming part of the planter having closer wheel connected to a walking arm with the walking arm in a rear closing wheel down position and the rear four-link in a down position. 
         FIG. 10B  is a side plane view of a trailing arm assembly forming part of the planter having closer wheel connected to a walking arm with the walking arm in a rear closing wheel upper position and the rear four-link in an upper position. 
         FIG. 10C  is a side isometric view of a trailing arm assembly forming part of the planter having an alternate style of closer wheel. 
         FIG. 11A  is a side plane view of a trailing arm assembly connected to a planter with a connection in accordance with one embodiment. 
         FIG. 11B  is a side plane view of a trailing arm assembly connected to a planter with a connection in accordance with one embodiment. 
         FIG. 12  is a side plane view of a trailing arm assembly connected to a planter with a connection in accordance with one embodiment. 
         FIG. 13A  is a side view of a trailing arm assembly with an alternative embodiment of the biasing member. 
         FIG. 13B  is a side view of a linkage assembly with the alternative embodiment of the biasing member of  FIG. 13A . 
         FIG. 14A  illustrates a top-rear perspective view of an agricultural tractor pulling an agricultural planter with a press wheel in accordance with an embodiment of the present invention. 
         FIG. 14B  illustrates a rear view of the agricultural planter showing the press wheel in accordance with an embodiment of the present invention. 
         FIG. 15  illustrates a perspective view of a tail section having a closing wheel assembly in accordance with various embodiments. 
         FIG. 16A  illustrates a rear perspective view of a tail section having a closing wheel assembly on a walking arm in accordance with various embodiments. 
         FIG. 16B  illustrates a rear perspective view of a tail section having a closing wheel assembly on a walking arm in accordance with various embodiments. 
         FIG. 16C  illustrates a side perspective view of a walking arm having a biased axel in accordance with various embodiments. 
         FIG. 16D  illustrates a biased axel in accordance with various embodiments. 
         FIG. 16E  illustrates a biased axel in accordance with various embodiments. 
         FIG. 16F  illustrates a side perspective view of a walking arm having a biased axel in accordance with various embodiments. 
         FIG. 16G  illustrates a biased axel in accordance with various embodiments. 
         FIG. 16H  illustrates a side perspective view of a biased walking arm in accordance with various embodiments. 
         FIG. 16I  illustrates a top perspective view of a biased walking arm in accordance with various embodiments. 
         FIG. 16J  illustrates a side perspective view of a biased walking arm in accordance with various embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     Disclosed herein is an agriculture planter having one or more trailing arm assemblies  100 . Each trailing arm assembly  100  may be variously equipped with a fertilizer furrow opener assembly  200 . Each trailing arm assembly  100  may also be variously equipped with a trailing furrow closer assembly  300 . The furrow opener assembly  200  may include an opener disc  260 . The furrow closer assembly  300  may include a closer wheel  360 . 
     In accordance with one embodiment, the fertilizer furrow opener assembly  200  may be connected to a planter frame  60  via a parallel linkage  220 , such as a four bar parallel linkage. This configuration, along with the location of the trailing arm assemblies  100 , provides a number of advantages. For example, the parallel linkage  220  allows the furrow opener assembly  200  and the furrow closer assembly  300  to move vertically following the terrain (e.g., contours of the field), obstacles (e.g., debris or the like) or similar changes in the field. The may be connected by a pivoting hitch  530  (see  FIG. 9 ). The movement allows the trailing arm assemblies  100  to follow or oscillate up and down as the discs and wheels negotiate over or through an obstruction in a field surface  400  without adversely impacting seed deposit depth or resulting in damage to the planter components. The parallel linkage  220  allows the trailing arm assemblies  100  to operate in substantially the same orientation throughout its range of motion relative to the planter frame  60 . For example, the orientation may be parallel to the frame, the field or the original position of the trailing arm assembly. The position may be in a plane that is orthogonal to the downward force exerted on the trailing arm assemblies  100  by a biasing member. The orientation may be consistent through its entire range of motion. The ability of the trailing arm assemblies  100  to adjust to the contours of the field surface  400  facilitates the disc (e.g.,  260 ) being in consistent contact with the field surface  400  to improve opening a fertilizer furrow and the trailing furrow closer wheel  360  being in contact with the field surface  300  to improve closing the seed and fertilizer furrows. The ability of the trailing arms  100  to oscillate over variances in the field surface  400  allows for the discs  260 ,  360  and wheel  265  to maintain a force in a consistent downward direction. In other words, the trailing arms  100  have relatively constant downward pressure, which allows for continuous opening and closing of furrows due to the constant pressure, which limits the seed depth from becoming too shallow or too deep. 
     Also, the trailing arm  100  being located at the rear or trailing end of the planter eliminates the issues with soil buildup on the gauge wheels  265  caused by fertilizer equipment being located on the front or leading end of the planter. The following discussion may include components for opening a fertilizer furrow, delivering liquid fertilizer from the distribution tube into the furrow, and closing the seed and fertilizer furrows. 
     For a detailed discussion of the planter and its features, reference is made to  FIGS. 1 and 2 .  FIG. 1  is a side view of an agriculture tractor  50  pulling the agriculture planter  70  and  FIG. 2  is a top-rear isometric view of the planter  70 . 
     As shown in  FIG. 1 , the planter  70  may include a tongue or hitch  72  for hitching the planter  70  to the hitch  55  of the tractor  50 . The tractor  50  tows the planter  70  in the direction of arrow F and provides power to the planter  70  (e.g., via a power take off (“PTO”)) for powering the operations of the planter  70 . 
     As illustrated in  FIG. 2 , the planter  70  may include a frame  75  from which the hitch  72  extends and the various planter components are supported. The various components of the planter  70  may include a plurality of trailing arm assemblies  100 . The trailing arm assemblies  100  may function as row units for planting seeds and distributing liquid fertilizer. 
     For a discussion of the various components of the trailing arm assembly  100  and the operation of those components, reference is made to  FIGS. 3-8 . Each trailing arm assembly may include an opener assembly  200 . Each trailing arm assembly  100  may additionally or alternatively include a closer assembly  300 . The opener assembly  200  may include an opener frame  210 . One or more of a furrow opener disc  260 , a gauge wheel  265 , seed hopper, and fertilizer reservoir may be attached to the opener frame  210 . The seed furrow opener disc  260  creates a furrow in which the planter  70  deposits seed in a manner well known in the art. The gauge wheel  265  assists in determining the depth at which the planter opener assembly  200  deposits the seed. The gauge wheel  265  is mounted to the frame  210  via a gauge wheel lever arm, which is pivotally coupled to the frame  210 . 
     The opener trailing arm assembly  200  may be coupled to the frame  75  via a connection that allows the trailing arm to move relative to the frame  75 . In accordance with various embodiments, the connection may be configured such that the approximate relative orientation between the opener trailing arm assembly  200  and the frame  75  may be maintained through the range of motion of the trailer arm assembly  200 . Any mechanical connection operable to maintain this relationship may be used. For example, the opener trailing arm assembly  200  may connect to the frame  75  via a parallel linkage  220 . In various embodiments, the parallel linkage  220  may be a four bar parallel linkage. 
     While an opener four bar parallel linkage  220  is shown in the figures, other connection mechanisms may be used as well. In various other examples, a slide mechanism, rail mechanism or a similar mechanism may connect the trailing arm assembly to the frame. 
     As indicated above, in various embodiments, the trailing arm assembly  100  may include a closing trailing arm assembly  300 . The closing trailing arm assembly  300  may include a closer frame  310 . The closer frame  310  may be connected to one or more furrow closer discs  360 , fertilizer opener discs, fertilizer injectors or similar planter implements. The seed furrow closer disc  360  closes a furrow over a deposited seed in a manner well known in the art. Any type of implement may be used. For example,  FIGS. 1-7  show a typical closer wheel on the closing trailing arm assembly  300 .  FIG. 8  shows an alternate style mohawk closing wheel on closing trailing arm assembly  300 . 
     The closer trailing arm assembly  300  may be coupled to the opener frame  210  via a connection that allows the closer trailing arm  300  to move relative to the opener frame  210 . In accordance with various embodiments, the connection may be configured such that the approximate relative orientation between the closer trailing arm assembly  300  and the opener frame  210  may be maintained through the range of motion of the closing trailing arm assembly  300 . Any mechanical connection operable to maintain this relationship may be used. For example, the closer trailing arm assembly  300  may connect to the opener frame  210  via a parallel linkage  320 . In various embodiments, the parallel linkage  320  may be a four bar parallel linkage. 
     While a closing four bar parallel linkage is shown in the figures, other connection mechanisms may be used as well. In various other examples, a slide mechanism, rail mechanism, or the like may connect the trailing arm assembly to the frame. 
     In accordance with various embodiments, the parallel linkage  220  may have a first link  226  and a second link  228 . The first link  226  may have two pivots  230 ,  234 . The pivot  230  may be located on a frame bracket  110 . The pivot  234  may be located on the first frame  210 . In this arrangement, the first link  226  allows movement between the frame bracket  110  and the first frame  210 . The second link  228  may have two pivots  232 ,  236 . The pivot  232  may be located on a frame bracket  110 . The pivot  236  may be located on the first frame  210 . The first link  226  and the second link  228  may be positioned in parallel relative to one another, meaning planes passing through pivots  230 ,  232  and pivots  232 ,  236 , respectively, may be parallel to one another. Pivots  232  and  230  may be positioned relative to one another in positions that are the same or substantially similar to pivots  236  and  234 . In this relationship, as the first link  226  and second link  228  articulate through their range of motion, they remain parallel to one another. Pivots  236  and  234  also maintain their position relative to one another. This arrangement allows the frame  210  to generally maintain its angular orientation throughout its range of motion. As shown in  FIG. 9 , the pivots may be discontinues across the links. For example, each end of each link may have its own pivot as shown in the exemplary  FIG. 9 . 
     In embodiments wherein the parallel linkage  220  is a four bar parallel linkage, the linkage  220  may also include a third link  227  and a fourth link  229 . Links  227  and  226  have the same pivots  230 ,  234  and form a top linkage  222 . Links  228  and  229  have the same pivots  232 ,  236  and form a bottom linkage  224 . 
     In accordance with various embodiments, the frame bracket  110  may be fixedly attachable or removably attachable to a planter towing frame  75 . The frame bracket  110  may have an engagement portion  112 . The engagement portion  112  may be flat (see  FIG. 9 ) or C-shaped (see  FIG. 3 ) operable to engage around frame  75 . Such an engagement portion may provide stability proximal to the sides of the linkage  220  such that twisting of the trailing arm assembly  100  is minimized. The frame bracket  110  may also include a mounting plate  114  that connects to a biasing member  240 . The mounting plate  114  may be located above, below, or in between pivots  230  and  232 . As shown in the  FIGS. 3 and 5 , the plate  114  may be below the pivots  230 ,  232  and also extend out under the top and bottom linkages  222 ,  224 . By extending out and under the linkages  222 ,  224 , the plate  114  may be positioned to stop the linkages from operating beyond a certain point. For example, the plate may limit the bottom linkage  224  from extending beyond 10-80 degrees off of the horizontal plane by being positioned to contact the linkage at an angular orientation between 20-70 degrees off horizontal. In other examples, this angle may be between 20-70 degrees or more particularly between 30-60 degrees. In one example, this angle may be approximately 35 degrees. By anchoring the biasing mechanism on the plate  114 , which forms part of the bracket  110 , at least one end of the biasing mechanism may be anchored to the frame  75  such that that anchor point has limited or no movement relative to the frame  75 . 
     The plate  114  may also form an anchor point for the biasing mechanism  240  below the pivots  230 ,  232 . In such a position, a tension-based biasing mechanism  240  may be used. One example of such a biasing mechanism may be a tension spring. The plate  114  may also anchor the biasing mechanism  240  between the pivots  230 ,  232  with the biasing mechanism being a torsion spring, for example. The plate  114  may also anchor the biasing mechanism  240  above the pivots  230 ,  232  with the biasing mechanism being a coil spring, air bag, or similar type of extension mechanism, for example. In another example, the biasing mechanism may be a hydraulic cylinder operable to extend or contract. A person of ordinary skill in the art, based on these examples, will appreciate that any of a variety of biasing member may be used with the system. These various embodiments are discussed in more detail below. 
     In accordance with various embodiments, the upper set of links  222  in the four bar parallel linkage  220  may be cross-braced such that link  226  and link  227  are integrally formed. Such integral formation may increase the lateral rigidity of the linkage  220 . Similarly, the lower set of links  224  may be cross-braced such that links  228  and  229  are integrally formed. The integral formation of either or both the upper and lower links may be accomplished by a variety of means. For example, the links may be cast, molded, machined, stamped, welded or formed by any other method. In one example, one or more plates  223  may connect one side of the upper links  222  with the other side of the upper links  222 . Similarly, plates  225  may connect one side of the lower links  224  with the other side of the lower links  224 . The plates  222  and  225  may be welded in place or attached with fasteners. 
     In accordance with various embodiments, the adjustable biasing member  240  may extend from the parallel linkage  220  to the frame bracket  110 . The adjustable biasing member  240  may be anchored to either the upper or lower links  222 ,  224  on one end of the adjustable biasing member  240  and anchored to the frame bracket  110  on the opposite end of the biasing member  240 . The biasing member may be positioned such that the biasing member biases the linkage  220  in a downward direction. In one example, the plate  114  may be positioned below the pivots  230  and  232 , with the biasing member  240  anchored to the plate  114  on one end and the biasing member  240  being anchored to the upper link  222  on the opposite end. In such an embodiment, the biasing member may also be an extension spring operable to exert a downward force on the linkage  220  by pulling the upper link toward the plate  114 . While the biasing member may exert a force directly between the linkage  220  and the plate  114 , the resultant force when reacting with the structure of the linkage  220  may be represented as F 1 . 
     In accordance with various embodiments, the parallel linkage  220  may be connected between the first frame  210  and the frame bracket  110  such that the parallel linkage maintains an angular orientation of the first frame  210 . This angular orientation may be orthogonal to the effective downward force F 1  of the adjustable biasing member  240 . While the actual force exerted by the biasing member  240  may not be vertical, the interaction between the biasing member  240  and the parallel linkage  220  may result in a vertical force on the first frame  210 . This vertical force may drive the first frame  210  and all implements attached thereto (e.g., the opener wheel  260  and the gauge wheel  265 ) against the ground  400 . 
     In accordance with various embodiments, the biasing member  240  may be adjustable. For example, the biasing member  240  may be adjustably connected to a portion of the parallel linkage (e.g., the upper linkage  222 ). The adjustable connection may allow the biasing member  240  to move along the length of the parallel linkage, with a position on one end of the parallel linkage placing the biasing member  240  in greater tension than a position on the opposite end of the parallel linkage  220  or with the position on one end of the parallel linkage  220  providing the biasing member  240  with greater mechanical advantage relative to the frame  110 . For example, an adjustable connection  250  may connect the biasing member  240  to the parallel linkage  220  at any of a variety of positions along about 50% of the length of the parallel linkage  220 . In one example, the adjustable connection may be a plurality of detents  250  formed in the parallel linkage  220 . The adjustable connection  250  may be an aperture extending through one or more of the links  226 ,  227 ,  228 , or  229 . The aperture may be an elongated slot with shorter slots extending transversely therefrom. An anchor member  242  may engage the aperture and be operable to slide along the elongated slot between the shorter slots. The biasing mechanism may pull the anchor member into the shorter slots, thereby forming a plurality of detents, allowing adjustability between each of the plurality of shorter slots. In one example, the anchor member  242  may be a pin that may extend between link  226  and link  227 . Each link may have the adjustable connection aperture  250  formed therein with the pin  242  engaged on each side. The biasing mechanism may connect to the pin forming the anchor on one side of the biasing mechanism with the upper linkage  222 . The pin may then be adjustable between the plurality of detents defined by the aperture  250 . In other examples, adjustment control  250  may be similar or the same as those discussed below with regards to the closer trailing arm assembly  300 . 
     In accordance with various embodiments, the first frame may include an adjustment mechanism operable to change the position of the gauge wheels  265  relative to the first frame  210 . The trailing arm assembly  200  may include an adjustment lever  251 . This lever  251  may allow the downward force exerted by the gauge wheels  265  to be adjusted. A linkage may extend between a bottom end of the lever  251  and the opener frame  210 . The position of the lever  251  may be set to set the gauge wheels  265  at a desired position relative to the opener frame  210 . The relationship between the opener frame  210  and the frame  75  is influenced by the parallel linkage  220  and the biasing member  240 . The influence may cause a change in force against the gauge wheels as the lever  251  is adjusted. When the lever  251  is in the first position fully extending the gauge wheels away from the frame  210 , the resulting downward force on account of the biasing member  240  may be at a maximum for the particular detent in which the biasing member  240  is set. To fully maximize this downward force, the biasing member  240  may be located in the detent on the linkage  220 , which maximizes the bias. (For example, as shown in  FIG. 1 , the detent distal from the bracket  110  provides the greatest mechanical advantage for the biasing member  240  and therefore the greatest downward force.) With the force F 1  maximized in the distal detent, the lever  251  may be positioned such that the wheels are fully extended, maximizing the overall force. The force may also be minimized by positioning the biasing member  240  in the detent in the minimum force position (e.g., as shown in  FIG. 5A , the detent proximal to the bracket  110  which provides the least mechanical advantage for the biasing member  240  and therefore the least downward force). With the force F 1  minimized in the proximal detent, the lever  251  may be positioned such that the wheels are fully retracted to the frame  210 , minimizing the overall force. One of ordinary skill in the art may recognize that intermediate adjustments may be made between the linkage control  250  and the frame control  251 . It may also be noted that while the frame control  251  may have an effect on force, it may also be used to merely set the depth of the opener disc  260  by adjusting the gauge wheels  265  relative to the opener disc  260 . 
     As discussed above, and in accordance with various embodiments, the planter may also include a second trailing arm assembly  300 . The second trailing arm assembly  300  may include implements operable to close and/or fertilize a furrow. This second trailing arm assembly  300  may include a closer frame  310 . The closer frame  310  may include one or more closing wheels  360 . As shown in  FIGS. 6-8 , the closer frame  310  may also connect to a fertilizer disc  380  and/or a fertilizer distribution system  390 . 
     The opener frame  210  and the closer frame  310  may be connected to one another such that the closer frame  310  may operatively move independently with respect to the opener frame  210  in the vertical direction. As shown in  FIGS. 5A and 5B , the closing wheels  360  may generally operate at a similar level as the gauge wheels  265 . However, the closer trailing arm assembly  300  may articulate vertically relative to the opener trailing arm assembly  200  as shown in  FIGS. 5C and 5D . Here, the closer trailing arm assembly  300  operates on a higher level (due to, e.g., an obstacle or field  400  contour or the like) than the opener trailing arm assembly  200 . 
     As discussed above, the closer trailing arm assembly  300  may be connected to the opener trailing arm assembly  200  in any manner known, especially in such a way as to provide the vertical articulating independence discussed above. In accordance with various embodiments, the closer frame  310  may be connected to the opener frame  210  via a second parallel linkage  320 . The parallel linkage  320  may have a first link  326  and a second link  328 . The first link  326  may have two pivots  330 ,  334 . The pivot  330  may be located on the opener frame  210 . The pivot  334  may be located on the closer frame  310 . In this arrangement, the first link  326  allows movement between the opener frame  210  and the closer frame  310 . The second link  328  may have two pivots  332 ,  336 . The pivot  332  may be located on the opener frame  210 . The pivot  336  may be located on the closer frame  210 . The first link  326  and the second link  328  may be positioned in parallel relative to one another, meaning planes passing through pivots  330 ,  332  and pivots  332 ,  336  respectively may be parallel to one another. Pivots  332  and  330  may be positioned relative to one another in positions that are the same or substantially similar to pivots  336  and  334 . In this relationship, as the first link  326  and second link  328  articulate through their range of motion, they remain substantially parallel to one another. Pivots  336  and  334  also maintain their position relative to one another. This arrangement allows the frame  310  to generally maintain its angular orientation throughout its range of motion. 
     In embodiments wherein the parallel linkage  320  is a four bar parallel linkage, the linkage  320  may also include a third link  327  and a fourth link  329 . Links  327  and  326  have the same pivots  330 ,  334  and form a top linkage  322 . Links  328  and  329  have the same pivots  332 ,  336  and form a bottom linkage  324 . 
     In accordance with various embodiments, the opener frame bracket  210  may include a bracket  316  fixedly attached or removably attachable thereto. The closer frame  310  may be movably attached to the bracket  316  via the parallel linkage  320 . The attachment may be such that it provides stability to the sides of the linkage  320  such that twisting of the trailing arm assembly  300  is minimized. The bracket  316  may also include a mounting plate  314  that connects to a biasing member  340 . The mounting plate  314  may be located above, below, or in between pivots  330  and  332 . As shown in the  FIGS. 3 and 5 , the plate  314  may be below the pivots  330 ,  332 . Similar to plate  214 , plate  314  may extend out under the top and bottom linkages  322 ,  324 . By extending out and under the linkages  322 ,  324 , the plate  314  may be positioned to stop the linkages from operating beyond a certain point similar to those discussed above. However, as shown in  FIGS. 3, 5 and 9 , the plate  314  may have lateral tabs, which perform a similar function. In this way, the plate  314  may limit the bottom linkage  324  from extending beyond a certain point. The plate  314  may also anchor the biasing member  340  below the rear lower pivot  332 . In one example, the plate  314  may support an anchor  315  for a biasing mechanism  340 . (See  FIG. 10A ) The anchor  315  may be an eye bolt located below the rear lower pivot  332  such that it can exert a downward force on the linkage  300 . 
     The plate may also anchor biasing mechanism  340 . By anchoring the biasing mechanism  340 , at least one end of the biasing mechanism  340  may be anchored to the opener frame  210  such that that anchor point has limited or no movement relative to the opener frame  210 . The plate  314  may form an anchor point for the biasing mechanism  340  below the pivots  330 ,  332 . In such a position, a tension-based biasing mechanism  340  may be used. One example of such a biasing mechanism may be a tension spring. Similar arrangements to those discussed above with regards to biasing mechanism  240  may be employed with the biasing mechanism  340 . A person of ordinary skill in the art, based on these examples, will appreciate that any of a variety of biasing members may be used with the system. 
     In accordance with various embodiments, the upper set of links  322  in the four bar parallel linkage  320  may be cross-braced such that link  326  and link  327  are integrally formed. Such integral formation may increase the lateral rigidity of the linkage  320 . Similarly, the lower set of links  324  may be cross-braced such that links  228  and  229  are integrally formed. The integral formation of either or both the upper and lower links may be accomplished by a variety of means. For example, the links may be cast, molded, machined, stamped, welded or formed by any other method. In one example, one or more plates  323  may connect one side of the upper links  322  with the other side of the upper links  322 . Similarly, plates  325  may connect one side of the lower links  324  with the other side of the upper links  324 . The plates  322  and  325  may be welded in place or attached with fasteners. 
     In accordance with various embodiments, the adjustable biasing member  340  may extend from the parallel linkage  320  to the opener frame  210 . The adjustable biasing member  340  may be anchored to either the upper or lower links  322 ,  324  on one end of the adjustable biasing member  340  and anchored to the opener frame  210  on the opposite end of the biasing member  340 . The biasing member may be positioned such that the biasing member biases the linkage  320  in a downward direction. In one example, the plate  314  may be positioned below the pivots  330  and  332 , with the biasing member  340  anchored to the plate  314  on one end and the biasing member  340  being anchored to the upper link  322  on the opposite end. In such an embodiment, the biasing member  340  may also be an extension spring operable to exert a downward force on the linkage  320  by pulling the upper link  322  toward the plate  314 . While the biasing member may exert a force directly between the linkage  320  and the plate  314 , the resultant force when reacting with the structure of the linkage  320  may be represented as F 2 . 
     In accordance with various embodiments, the parallel linkage  320  may be connected between the closer frame  310  and the opener frame  210  such that the parallel linkage maintains an angular orientation of the closer frame  310 . This angular orientation may be orthogonal to the effective downward force F 2  of the adjustable biasing member  340 . While the actual force exerted by the biasing member  340  may not be vertical, the interaction between the biasing member  340  and the parallel linkage  320  may result in a vertical force on the closer frame  310 . This vertical force may drive the closer frame  310  and all implements attached thereto (e.g., the opener wheel  360  and the gauge wheel  365 ) against the ground  400 . 
     In accordance with various embodiments, the biasing member  340  may be adjustable. For example, the biasing member  340  may be adjustably connected to a portion of the parallel linkage (e.g., the upper linkage  322 ). The adjustable connection may allow the biasing member  340  to move along the length of the parallel linkage  320 , with a position on one end of the parallel linkage placing the biasing member  340  in greater tension than a position on the opposite end of the parallel linkage or with the position on one end providing the biasing member  340  with greater mechanical advantage than the position on the other end. For example, an adjustable connection  350  may connect the biasing member  340  to the parallel linkage  320  at any of a variety of positions along about 50-80% of the length of the parallel linkage  320 . In one example, the adjustable connection  250  may be a plurality of detents  351  formed in the parallel linkage  320 . The adjustable connection  350  may be an aperture extending through one or more of the links  326 ,  327 ,  328 , or  329  similar to the structure discussed above with respect to linkage  220  and adjustable connection  250 . Or the adjustable connection may be an aperture  350  extending through the connecting plate  323 . The aperture may be an elongated slot  350  with shorter slots  351  extending transversely therefrom. An anchor member  342  may pass through the aperture  350  and be operable to slide along the elongated slot  350  between the shorter slots  351 . In one example, the anchor member  342  may be a lever that may extend through plate  323 . The biasing mechanism  340  may connect to the lever  342 , forming the anchor on one side of the biasing mechanism  340  with the upper linkage  322 . The pin may then be adjustable between the plurality of detents  351  defined along aperture  350 . 
     In accordance with various embodiments, the planter may have the first trailing arm section  200  attached to the planter frame  75  via a four bar parallel linkage  220  and the second trailing arm section  300  attached to the first trailing arm section  200  via the second four bar parallel linkage  320 . The first four bar parallel linkage  220  and the second four bar parallel linkage  320  may be biased toward the ground  400 . The first bias mechanism  240  may bias both the first trailing arm section  200  and the second trailing arm section  300 . The second bias mechanism  340  may only bias the second trailing arm section  300 . The first and second bias mechanisms may include their own individual adjustment systems  250  and  350 , respectively. These mechanisms may adjust the respective forces exerted by the bias mechanisms associated therewith. A third adjustment mechanism  251  may be included in the first trailing arm section  200 . The third adjustment mechanism  251  may adjust the position of the first trailing arm section  200  (more specifically, the frame  210  associated therewith) with respect to the ground. This adjustment may translate into an additional adjustment of force on the first biasing mechanism  240 . 
     It may be noted that the directions used herein may be generally stated, while in actual application in the field the conditions may vary the practical effect. For example, a tractor  50  pulling planter  70  up a hill may result in the forces F 1  or F 2  being non-vertical while still being generally normal to the ground or normal to the direction of travel of the system as a whole. Or, as debris or small hills may have a very temporary effect on the angle of the system as a whole, the overall effect or the larger average effect is that the effective force is generally normal to the average plane of the field  400  or generally normal to the average direction of travel of the system. 
     As shown in  FIG. 9  the closing assembly  300  may include staggered closing wheels  360   a  and  360   b  attached an articulating bracket  800 . The articulating bracket  800  may provide an additional degree of articulation relative to the closing assembly  300 . As indicated above, opener assembly  200  provides a first degree of articulation moving the components rearward of opener assembly  200 , e.g. the closing assembly  300  and the articulating bracket  800 . The closing assembly  300  provides a second degree of vertical articulation that is independent of the opener assembly  200 , but articulates the components rearward of the closing assembly  300 , e.g. the articulating bracket  800 . The articulating bracket  800  provides a third degree of vertical articulation that is independent of the opener assembly  200  and the closing assembly  300 . The articulating bracket  800  is operable to move components attached thereto without causing movement of forward components such as the opener assembly  200  and the closing assembly  300 . For example, staggered closer wheels or a fertilizer disc may be attached to the articulation bracket  800 . These components may articulate independent of the linkage of the closing assembly  300 . In accordance with one embodiment, the articulation bracket  800  may be a pivotable arm bracket as disclosed in any of the various embodiments of U.S. Pat. Pub. No. 2013/0263767, which is hereby incorporated by reference in its entirety. As shown, in  FIG. 9  the staggered closing wheels  360   a  and  360   b  may be v-tine closing wheels discussed in more detail below. 
     The articulation of the articulation bracket  800  may be limited by an upper stop  510 . The stop may limit the upward travel of the rear portion of the articulation bracket  800 . The stop  510  may part of or a protrusion extending from the closing frame  310 . As shown in  FIG. 9  the stop  510  may be a sheet metal bracket that connects the pivot  334  and pivot  336  forming a part of the parallel link suspension. 
     As shown in  FIGS. 10A and 10B , the closing assembly  300  may provide articulation to the closing wheels and/or fertilizer disc between a lower position shown by dotted line “a” in  FIG. 10A  and an upper position shown by line “a” in  FIG. 10B . When these articulation measurements are compared between the parallel linkage disclosed herein and the traditional swing arm linkage it is noted that the parallel linkage has, in one example, 7 inches travel compared to a similarly sized traditional setup of the swing arm linkage, which only achieves 4 inches of travel up and down. When measuring lateral movement is measured that a traditional swing arm linkage yields 2 inches of lateral movement when rotated from a down to an up position. This results in a wheel that is further away from center of Double disc openers in the 4 inches of travel. Whereas, the parallel linkage disclosed herein moves only ½ away from the center of Double Disc openers in the exemplary 7 inches of travel. The swing arm distance for closing wheels or press wheels through the range of motion is 1 inch wider when fully lifted than when down on ground contact. Whereas, the parallel linkage doesn&#39;t change throughout the 7 inches of travel. The reason is that due to the geometric configurations, the parallel linkage stays parallel, while the swing arm design makes an arch when moving up and down. By adding the parallel linkage to the closing wheels numerous unexpected benefits are realized. For example, blank areas through ditches and over the tops of terraces are limited, wheel travel can be approximately doubled over similar sized swing arm setups, the bounce in row units when planting above 5 MPH is limited, less down pressure can be run on row units, the press wheels lateral movement can be limited so the seed furrow is more consistent as the linkage flexes, there is even more depth control of planter unit, seed to soil contact is improved for uniform emergence, pinch points are minimized as the wheels travel, use with other moving devices such as the walking arms discussed herein is improved, and travel of parallel linkage can be kept parallel to the ground. 
       FIG. 10A  shows the trailing arm assembly  300  having the closer wheel  360   a  connected to an articulating bracket  800  with the closing wheel  360   a  in a down position and the rear four-link in a down position. In this position, both closing wheels  360   a, b,  may be positioned below the hitch  530 .  FIG. 10B  shows the trailing arm assembly  300  with the closer wheel  360   a  connected to an articulating bracket  800  in a wheel upper position and the rear four-link in an upper position. In this configuration, the rear closing wheel  360   a  may be close to or above the hitch  530  with the front closing wheel  360   b  being close to the same height as the hitch  530  or about the same height as the rear lower pivot  332 . The difference in height is illustrated as the comparison between line  332 H and line b. In some embodiments, the combination of the articulating bracket  800  and the rear parallel link may allow at least one of the closing wheels to articulate between at least half the wheel height and 1 and ½ wheel heights. 
     As shown in  FIGS. 10A-10C , the biasing member  340  may be adjustable via handle  342 . The  340  may be attached to the anchor  315  which is located below the rear lower pivot  332 . The biasing member may exert a down ward force on the upper linkage. The tension in the biasing member  340  may be adjusted via adjustment linkage  600 . The biasing member  340  may attached to a first end  612  of the adjustment linkage  600 . The adjustment linkage  600  may pivot about a pivot  622  that is connected to the upper linkage via bracket  620 . By moving the handle  342  backwards, the adjustment linkage  600  may pivot raising the first end  612  elongating the biasing member  340  and thereby creating more tension in the member. The tension may be communicated through the pivot  622  and bracket  620  into the upper linkage creating a downward force on the linkage. 
       FIG. 10A-C  illustrates various views of a trailing arm assembly connected to a planter with a connection in accordance with one embodiment. While the embodiments and examples provided below are described with respect to the trailing arm assembly connecting to a planter (e.g. a closing assembly connected to an opener assembly) it may be appreciated that the concepts are not so limited. For example, each of the embodiments and examples may similarly be applied to a trailing arm planter connected to the rear of a tractor or other farm implement as a person of ordinary skill in the art would understand based on the disclosure provided herein. As illustrated as an example in  FIGS. 10A-C , a trailing arm assembly  300  may forwardly connect to another farm implement such as a plantar assembly  200 . The plantar assembly  200  may also be a trailing arm assembly. In accordance with various embodiments, the trailing arm assembly may include frame bracket  316 . The frame bracket  316  may have a connecting bracket  1200  extending therefrom. The connecting bracket  1200  may be operable to attach the trailing arm assembly  300  to another implement such as plantar  200 . The connection bracket  1200  may be cantilevered from the frame bracket  316  toward the other implement such that, the connection bracket  1200  is suitably positioned to connect direct to the other implement. The connection bracket may be a plate suitable to mate flush against a planter unit (see e.g.  FIG. 16B ). The plate may have a thickness that allows it to be sandwiched between other plates  1220 ,  1230  above and below forming a double shear attachment. 
     In accordance with various embodiments, the connection bracket  1200  may extend from the frame bracket  316  at a location that provides suitable stability and flexibility between the trailing arm assembly (e.g. closer  300 ) and the other implement (e.g. planter  200 ). For example, the connection bracket  1200  extends from the frame bracket  316  above at least one pivot of the parallel linkage, such as the pivot  332  or the pivot  330  on the bracket  316 . In a preferred embodiment, the pivot is the lower pivot  332 . The connection bracket  1200  may be positioned closer to the lower pivot  332  than to the upper pivot  330 . In various embodiments, the cantilevered connection bracket  1200  includes a gusset  1205  positioned to support a lower portion of the connection bracket  1200 . In one example, the gusset  1205  extends from adjacent or around the lower pivot  332 . 
     In accordance with various embodiments, the connection bracket  1200  may provide lateral movement between the trailing arm assembly and the implement it is attached to. For example, the connection bracket  1200  may include a pivot attachment  1210  such the trailing arm assembly pivots relative to the plantar around the axis device by the pivot attachment  1210 . This axis may be vertical. 
     With respect to the various connecting brackets discussed herein, the connecting bracket (e.g.  1200 ) may be integrally formed with the frame bracket or it may be removably attached to the frame bracket. 
       FIG. 11A  is a side plane view of a trailing arm assembly connected to a planter with a connection in accordance with one embodiment. As illustrated as an example in  FIG. 11A , a trailing arm assembly  300  may forwardly connect to another farm implement such as a plantar assembly  200 . The plantar assembly  200  may also be a trailing arm assembly. In accordance with various embodiments, the trailing arm assembly may include frame bracket  1316 . The frame bracket  1316  may have a connecting bracket  1300  extending therefrom. The connecting bracket  1300  may be operable to attach the trailing arm assembly  300  to another implement such as plantar  200 . The connection bracket  1300  may be cantilevered from the frame bracket  1316  toward the other implement, such that the connection bracket  1300  is suitably positioned to connect direct to the other implement. The connection bracket may be a plate suitable to mate flush against a planter unit (see e.g.  FIG. 16B ) or against an adapter. 
     In accordance with various embodiments, the connection bracket  1300  may extend from the frame bracket  1316  at a location that provides suitable stability and flexibility between the trailing arm assembly (e.g. closer  300 ) and the other implement (e.g. planter  200 ). For example, the connection bracket  1300  extends from the frame bracket  1316  above at least one pivot of the parallel linkage, such as the pivot  332  or the pivot  330  on the bracket  316 . In a preferred embodiment, the pivot is the lower pivot  332 . The connection bracket  1300  may be positioned closer to the lower pivot  332  than to the upper pivot  330 . In various embodiments, the cantilevered connection bracket  1300  includes a gusset  1305  positioned to support a lower portion of the connection bracket  1300 . In one example, the gusset  1305  extends from adjacent or around the lower pivot  332 . 
     In accordance with various embodiments, the connection bracket  1300  may include plate  1307  positioned between the trailing arm assembly and the implement it is attached to. The connection bracket  1300  may include one or more features for cradling the adjacent implement. For example, the connection bracket  1300  may include one or more saddles  1311  for engaging the planter bracket. The saddle  1311  may be suitable to cradle one or more portions of the adjacent implement upon connection. For example, the saddle  1311  may be a concave notch formed within a tab extending up from the plate  1307  or the connection bracket  1300 . The saddle  1311  may receive a cylindrical member  1330  that extends from or passes through the adjacent implement. The plate  1307  may have apertures  1312  positioned to receive various fasteners. In one example the apertures  1312  may be formed on a secondary plate  1309  that is wider than plate  1307 . The apertures may be located to receive u-bolts  1310 . The u-bolts  1310  may extend over the protrusion  1330  and pass through the apertures  1312  to be fastened on the opposing side with a fastener. In this way, the saddle  1311  engages the horizontal cylinder  1330  extending from or through the planter and the u-bolt pulls the planter towards the saddle  1311 . 
     The connection bracket  1300  may further comprise a brace  1320  that extends from a first portion of the connection bracket  1300  longitudinally forward of the saddle  1311 . The brace  1320  forms a second attachment to the adjacent implement with the saddle  1311  forming a first attachment point. The two attachment points provide greater stability and limits rotational movement about an axis that is transverse to the direction of travel of the machine. In one example the brace  1320  extends from the farthest forward portion of the connection bracket  1300  at an angle upward to connect with the planter at a connection  1325 . In one example the brace may be connected approximately between the disc scrapers on the planter. In accordance with various embodiments, the brace  1320  and the saddle  1311  are integrally formed with a plate  1307 . The plate  1307  is then removably attachable to the connection brace  1300  such that the brace  1320  and the saddle  1311  are removable from the trailing arm assembly  300 . In this way, the trailing arm has flexibility to adapt to different connection points on different implements. For example, a John Deer planter may have a flat mounting surface whereas a Case IH planter may have an alternate mount. In accordance with various embodiments, the brace  1320  and the saddle  1311  are integrally formed with the connection bracket  1300 , which is integrally formed with the frame bracket  1316 . 
       FIG. 11B  is a side plane view of a trailing arm assembly connected to a planter with a connection in accordance with another embodiment. Each of the brackets discussed with regards to this embodiment or other embodiments can have more or fewer components than those recited. For example, the embodiment shown in  FIG. 11B  includes a connection bracket  1300  having some similar features to those shown in the embodiment of  FIG. 11A . For example, the trailing arm assembly  300  may forwardly connect to another farm implement such as the plantar assembly  200 . The trailing arm assembly includes frame bracket  1316 . The frame bracket  1316  may have a connecting bracket  1300  extending therefrom. The connecting bracket  1300  may be operable to attach the trailing arm assembly  300  to another implement such as plantar  200 . The connection bracket  1300  may be cantilevered from the frame bracket  1316  toward the other implement, such that the connection bracket  1300  is suitably positioned to connect direct to the other implement. 
     The, the connection bracket  1300  may extend from the frame bracket  1316  similar to what is discuss and shown with regards to  FIG. 11A . The connection bracket  1300  may include plate  1307  positioned between the trailing arm assembly and the implement it is attached to. The plate  1307  may have one or more braces extending therefrom. For example, the plate  1307  may include a horizontal brace  1720  and a vertical brace  1710 . The combination of the two braces may limit rotation of the closer  300  relative to the planter  200 . Each brace may have a closer end proximal to the closer assembly and a planter end proximal to the planter. The closer end may be fixedly attached to the plate  1307 . The plate  1307  may be welded, fastened, or otherwise attached to the closer. The planter end of the braces may be removably attached to the planter. For example pins, bolts, or other attachment mechanisms (e.g.  1740  and  1730 .) may attach the braces  1710  and  1720  to the planter In some embodiments the connector may be fixedly attached to the planter and removably attached to the closer or removably attached to both. One or both of the braces  1710 ,  1720  may be configured to match the form, shape, profile or other characteristic of the planter or closer. For example, one brace (e.g.  1710 ) can be placed between two beams of the planter so that the brace is placed in double shear. In another example, one brace (e.g.  1720 ) may be split in a y-shape such that the planter can have a beam pass through the brace, such that the brace holds the planter beam in double shear. 
       FIG. 12  is a side plane view of a trailing arm assembly connected to a planter with a connection in accordance with one embodiment. In accordance with various embodiments, a connection bracket  1400  may include two rearwardly facing extensions. For example, a first bracket  1410  may be position above a second bracket  1418 . One or both portions may be cantilevered from the frame bracket  1416 . The first bracket  1410  may be near or above the lower pivot  332  with the second bracket  1418  below the first bracket. The first bracket  1410  and the second bracket  1418  are attachable to the adjacent implement via pivot points  1412  and  1413  respectively. The second bracket  1418  may connect to a bracket  1618  on the adjacent implement  1600 . One or more of the first bracket  1410  and the second bracket  1418  may be attachable to the planter in double shear. For example, the first bracket  1410  includes two cantilevered tabs positioned relative to one another to engage the planter in double shear. The second bracket  1418  includes two cantilevered tabs positioned relative to one another to engage the planter in double shear. These extensions may also take other forms than tabs. The second bracket  1418  extends from a mounting plate  1414  that is proximal to a biasing member  340 , wherein the second bracket  1418  and the biasing member  340  are mounted on opposite sides of the mounting plate  1414 . 
       FIG. 13A  is a side view of a trailing arm assembly with an alternative embodiment of the biasing member. As indicated above, the biasing mechanism may be any mechanism suitable to bias the furrow closer assembly  300  in either an upward or downward direction. For example, the biasing mechanism may be an extension spring, a coil spring, an air bag, a hydraulic cylinder, or similar types of mechanisms. Each of these biasing mechanisms may be structured such that they bias the furrow closer assembly  300  in a raised or lowered position. Each of these biasing mechanisms may be operable to extend or contract thereby biasing the closer assembly  300 . A person of ordinary skill in the art, based on these examples, will appreciate that any of a variety of biasing members may be used within the various embodiments of the planter systems discussed herein. 
     In accordance with one example, as illustrated in  FIG. 13A , the biasing member is a hydraulic cylinder  1560 . While the biasing member is further discussed herein by way of example, as a hydraulic cylinder, it will be appreciated that the associated structure and functionality may also be utilized with other embodiments having biasing members such as an air cylinder, air bag, coil spring or the like, which can be used as alternatives. The hydraulic cylinder  1560  includes an end that is fixed relative to the furrow opener assembly  200 . In  FIG. 13A , the furrow opener assembly  200  is represented by the connecting bracket  1300 , the frame bracket  1516 , or biasing bracket  1517 , which may also be fixed relative to the furrow opener assembly  200 . The hydraulic cylinder  1560  also includes an end that moves relative to the furrow opener assembly  200 . For example, the second end of the hydraulic cylinder  1560  moves with one or more of the links (e.g.,  326 ,  1528 ) or closer bracket  310 . This allows the hydraulic cylinder  1560  to bias the furrow closer assembly  300  by, for example, exerting a down pressure on the trailing arm assembly  300 . 
     In various examples, the end of the hydraulic assembly that is fixed with respect to the furrow opener assembly  200  may be a pivot  1564  attachment. In various examples, the end of the hydraulic assembly that moves with respect to the furrow opener assembly  200  may be a pivot  1566  attachment. The pivot  1564  may be positioned on, adjacent to, or in connection with the connecting bracket  1300  or the frame bracket  1516 . For example, the pivot  1564  may form a part of a biasing bracket  1517 . In various examples, the biasing bracket  1517  may extend from the frame bracket  1516 . The biasing bracket  1517  may be an integral extension of the frame bracket  1516  or the biasing bracket  1517  may be connected via fasteners or another bracket to the frame bracket  1516 . 
     In various examples, the pivot  1566  may be located on a portion of the linkage that is movable with respect to the furrow opener assembly  200 , such as one or more of the links (e.g.,  326 ,  1528 ) or closer bracket  310 . To maximize length and or leverage of the hydraulic cylinder  1560 , the pivot  1566  may be located on the lower link  1528  or the closer bracket  310 . As illustrated in  FIGS. 13A and 13B  and in accordance with various examples, the hydraulic cylinder  1560  extends between pivot  1564  on the biasing bracket  1517  and pivot  1566  on the lower link  1528 . 
     In various examples, the linkage assembly includes a variety of mounting positions for the pivot  1566 . The variety of mounting positions allows a user to adjust the leverage and stroke that the hydraulic cylinder inputs into the linkage assembly. The variety of mounting positions may be located on one linkage member or on more than one linkage member (e.g.,  1528 ,  310 , or  326 ). In one particular example, as shown in  FIGS. 13A and 13B , link  1528  may include a plurality of pivot locations such as pivot  1566  and pivot  1568 . These pivot locations may be apertures, fasteners, brackets, or the like suitable to form a pivotable attachment between the two components. The linkage system may have a distance L, as shown in  FIG. 13B , between connected link pivots such as  332  or  336 . In one example, the pivot  1566  may be positioned at a distance of M 2  that is less than ½ of L away from pivot  332 . In a more particular example, the pivot  1566  may be positioned at a distance of M 2  that is between ′/4 of L and ½of L away from pivot  332 . In still a more particular example, the pivot  1566  may be position at a distance of M 2  that is about ¼ of L way from pivot  332 . In one example, the pivot  1568  may be positioned at a distance of M 3  that is more than 1 of L away from pivot  332 . In a more particular example, the pivot  1566  may be positioned at a distance of M 3  that is between ½of L and ¾ of L away from pivot  332 . In still a more particular example, the pivot  1566  may be positioned at a distance of M 3  that is about % of L way from pivot  332 . 
     The lower link  1528  may be a straight link extending between pivots  332  and  336  as shown and described in other embodiments herein. In another example, lower link  1528  may be a have a curved shape with a convex side facing the side from which the hydraulic cylinder  1560  extends. This curved shape may be defined by a plurality of straight splines forming the curve or it may have a smooth curvilinear or arched shape. As illustrated in  FIG. 13B , the lower link  1528  may have a plurality of sections that provide the curved shape. For example, the low link may have a first section  1528   a  and a second section  1528   c  that support a third section  1528   b  that is substantially parallel with the link structure of the upper link  326 . In one example, the adjustable mounting locations  1566  and  1568  are positioned along the parallel section  1528   b.    
     In accordance with various embodiments, the pivot  1564  may be positioned relative to the one or more corresponding pivots (e.g.,  1566  or  1568 ) such that the relationship allows for maximum stroke length and or maximum leverage. In one embodiment, the pivot  1564  may have a distance M 1  from the line that passes through both link pivots  330  and  332 . In one embodiment, M 1  may be about the same as M 2 . In one embodiment, M 1  may be less than M 2 . In one embodiment, M 1  may be about the same as M 3 . In one embodiment M 1  may be between M 2  and M 3 . In one embodiment M 1  may be more than M 3 . 
     As shown in  FIGS. 13A and 13B  the hydraulic cylinder  1560  is in single shear pivot attachment with biasing bracket  1517  at pivot  1564 . However, it is appreciated that this system can also be structured in double shear by providing a second biasing bracket that corresponds to biasing bracket  1517  on the opposite side of the hydraulic cylinder  1560 . While discussed herein with respect to the two dimensional links shown (e.g.,  1516 ,  326 ,  310 , and  1528 ) in  FIGS. 13A and 13B , it should be appreciated that these various embodiments of the link system correspond to the other embodiments of the link system discussed throughout and as such while not discussed with respect to  FIGS. 13A and 13B , there may be corresponding links, not shown in  13 A and  13 B, that make this a four link system similar to the other embodiments discussed throughout. 
     In accordance with various embodiments, the biasing bracket  1517  may have a sufficient length to fit the hydraulic cylinder  1560  between the pivot  1564  and the corresponding movable link that the hydraulic cylinder  1560  is attached to. The length of the hydraulic cylinder  1560  is a length sufficient to allow the closing assembly to adequately navigate over debris in the field. As one example, the hydraulic cylinder  1560  has a stroke between about 11/2 inches and about 31/2 inches. Depending on the geometry of the hydraulic cylinder attachments and linkage geometry, this length can correspond to a closing assembly  300  that travels between about 51/2 inches and about 71/2 inches. In a preferred embodiment, the cylinder includes about a 21/inch stroke (about 8 inches over collapsed length) that corresponds to a closing assembly travel of about 6 ½ inches. 
     The hydraulic cylinder  1560  may be a single action cylinder with a small hydraulic accumulator  1565 . The hydraulic cylinder  1560  may be a self-contained system with the accumulator  1565  mounted on or near the linkage assembly such as proximal to the frame bracket  1516 . The accumulator may be connected with the hydraulic cylinder  1560  in such a way as to allow the hydraulic cylinder  1560  to have a spring action that corresponds to an expandable fluid charge in the accumulator. For example, the accumulator can be charged with dry nitrogen gas that exerts a pressure on the hydraulic fluid in the hydraulic cylinder  1560  forcing the closing assembly  300  toward the ground. Other gases may be used as well. The system is adjustable with a hand pump and a quick attach hydraulic port that allows a change in the gas pressure or an increase of hydraulic fluid to increase or decrease the amount of down pressure on the closing assembly  300 . In a preferred embodiment, the system produces about 100 lbs. of down force on the closing assembly  300 . However, this force can be adjustable depending on the field conditions, the type of crops, or user preference. The system may be adjustable to each row or as a gang to all the row unites. 
     In accordance with other embodiments, the biasing mechanism may be a unit that only utilizes compressible fluids such as an air cylinder or an air bag. The structure of the system is similar to the structure discussed above. An air cylinder system utilizes similar type of cylinder and mount as the hydraulic system, but it uses air pressure to increase and or decrease the force needed to close the seed furrow. An air system ties into the farmers or planters existing air system. This air system is used to control down pressure of each row unit as an individual entity or the gang as a whole. An air system allows a user to tap into the present air system or down force system of the existing front parallel linkage system or air bag systems that many typical planters or drills have. This also allows the air system on the closing assembly  300  to maintain a substantially uniform pressure on both the opener discs. In some situations an increased air supply can provide an increase pressure on the closing system over the plantar unit. For example, when planting in a rough terrain or up and over terraces or through ditches, the pressure on the opener discs when topping a terrace will decrease, forcing air to be transferred from the front system to the back system where the press wheels need more pressure to close the seed furrow properly. Air can also be transferred from the back to the front when the closing assembly  300  bottoms out and the disc opener assembly  200  need more pressure to stay in the ground. The maximum amount of pressure may be controlled by a regulating adjustable valve on each individual row unit in line from the opener parallel down pressure system into the air cylinder. This will let the operator regulate the amount of down force or up force with this valve thus customizing each row for each and every differing planting condition in the field. 
     As indicated above the planter unit may utilize multiple articulating trailing arm assemblies. These assemblies may assert a uniform downward force that is generally perpendicular to the ground. This force may be beneficial to utilizing press wheels and closing wheels as they typically bring up the rear of the mechanism. In accordance with various embodiments these wheels may be a v-tined wheel suitable to condition the soil as press wheels, closing wheels, or some other implement. 
     Aspects of the subject matter discussed herein include the use of a wheel on the rear of an agricultural seed planter and drill. The wheel includes a center rim and tines extending from the rim. The rim may also extend radially beyond the tines such that when pressing down on top or side of the closed furrow, the rim makes small cuts into the soil to aid in the sprouting of the plant. The tines are arranged on the exterior portion of the rim such that at least a portion of at least one tine may be in contact with the soil during a full rotation of the wheel. The rim and tines press down on top of the closed furrow over the planted seed or the side of an open furrow to close the furrow. As the press wheel rotates, the tines contact the soil proximal to the location over or near the seed. As the wheel continues to rotate the tines begin to engage the soil outwardly. 
     In accordance with various embodiments, as shown in the top-rear perspective view of  FIG. 14A , an agricultural seed planter and drill  1200  may include a tongue or hitch  1215  for hitching the planter  1200  to the hitch  1220  of the tractor  1205 . The tractor  1205  tows the planter  1200  in the direction of arrow F and provides power to the agricultural seed planter and drill  1200  via a power take-off for powering the operations of the planter  1200 . 
     As illustrated in  FIG. 14A , the agricultural seed planter and drill  1200  may include a frame  1245  from which the hitch  1215  extends and the various planter components are supported. The various components of the agricultural seed planter and drill  1200  may include row units  1250  and a liquid fertilizer distribution tube  1255 . The distribution tube  1255  distributes the liquid fertilizer to the various row units  1250 . 
     In accordance with various embodiments, the agricultural seed planter and drill  1200  may have a series of the row units  1250 . Each row unit may include a furrow opener disc  1260 , a gage wheel  1265 , a frame  1270 , and a seed hopper  1275 . The seed furrow opener disc  1260  creates a furrow in which the planter  1200  deposits seeds. The gage wheel  1265  assists in determining the depth at which the planter  1200  deposits the seed. The agricultural planter  1200  may have a series of trailing arm assemblies  300  each equipped with a trailing furrow closer wheel  1315  (while not shown as the wheels described herein the wheels  315  may also be the wheel  1100 ) followed by a press wheel assembly  1100 . This configuration allows for treating the soil after the furrow has been closed by the closing wheel. In accordance with various embodiments, the wheel  1100  may form part of the main agricultural seed planter assembly  1200  or the wheel  1100  may extend off of the main agricultural seed planter assembly via a trailing arm frame  1320  or another bracket. 
     In various embodiments, the planter  1200  may include a fertilizer furrow opener disc  1305  operable to cut a furrow proximal to the seed furrow  1280  for depositing fertilizer at the time of planting. In various embodiments, the planter  1200  may include a fertilizer furrow opener disc  1305  leading the furrow closer wheel  1315  (which can be wheels  1100  as shown in  FIGS. 15 and 16 ) and/or the press wheel assembly  1100 . 
     As described herein, the wheel  110  may be described as a press wheel however it may also be utilized as a closing wheel or other such implement suitable to condition the soil  400  in different ways. For example, the press wheel assembly  1100  may condition soil over the area affected by the closed fertilizer furrow in addition to the seed furrow  1280 . Reference to wheel assembly  1100  does not limit it to such a use as other embodiments are discussed herein and a person of ordinary skill in the art understands the general application as a farm implement based on the disclosure provided herein. 
     In one embodiment, the closing wheels  1315  include an exterior radial surface  1340  which contacts the soil closing the open furrow. As the closing wheels  1315  close the open furrow  1280 , a closed furrow seam  1281  is formed as the walls collapse against one another. In accordance with various embodiments, as illustrated in  FIG. 14B and 3A -B, the press wheel  1100  may follow the closing wheels  1315  and condition the closed furrow seam  1281 . In doing so, the press wheel  1100  applies a downward pressure on the closed furrow  1281 . The pressure against the soil may come from tread portions  1120  and/or a rim. The pressure may be applied without applying pressure from webbing or other material linking the tread portions  1120  at any point other than that proximal to a center plane. In one example, the tread portions  1120  may extend from each side of a center plane, which as shown in  FIG. 14B  may be a rim. Each tread wheel may include a plurality of tread portions  1120   a,    1120   b,  and  1120   c  as shown in  FIGS. 16-17 . 
     In accordance with various embodiments, the press wheel  1100  may be approximately centered on the closed furrow seam  1281 . This position may be independent of the location of either the opening wheels  1260  or the closing wheels  1315 . But, the closing wheels  1315  may be positioned on the sides of the open furrow  1280  in order to close the furrow. As such, additionally or alternatively the press wheel  1100  may be centered between the closing wheels. However, in embodiments with a single closing wheel or offset closing wheels, the press wheel may be positioned on the side of the closing wheel which directs soil into the open furrow. In accordance with various embodiments, the press wheel  1100  may be positioned relative to the opening wheel (or opening wheels)  1260  regardless of the presence or position of closing wheels. In such an embodiment, the press wheel  1100  may follow the opening wheel  1260 . The press wheel  1100  may be positioned so that the press wheel  1100  is centered in line with or approximately in line with the location at which the opening wheel  1260  engages or is designed to engage the soil. In other embodiments, the press wheel  1100  may be offset from the location of engagement between either the opening disk and the soil or the closing disk and the sides of the furrow  1280 . For example, the press wheel  1100  may be aligned such that one set of tines  1120  may extend from one side of the press wheel  1100  and may engage or press on the closed furrow seam  1281 . 
     As the press wheel  1100  creates a downward pressure, the press wheel  1100  and the tread portions  1120  may imprint a tread pattern  1183  on the ground. The tread pattern  1183  may resemble a chicken track. The imprint pattern may be formed because the volume between tread portions  1120  may not contact the soil, limiting contact to either or both of the rim and the tread portion  1120 . In one example, two lines may extend from and at an angle to a line passing at or close to the closed furrow seam  1281 . The two lines may be angled in the same direction. The lines may be symmetric, having a common point meeting proximal to the center plane and pointing away from the direction of travel of the tractor  1205 . In another example, the lines may be non-symmetric but still have a common point meeting proximal to the center plane and pointing away from the direction of travel of the tractor  1205 . In another example, the lines may be staggered, not having a common point proximal to the center plane but still angled such that the imprint points away from the direction of travel of the tractor  1205 . 
     U.S. patent application Ser. No. 14/835,553, filed Aug. 25, 2015, is incorporated herein by reference in its entirety and it illustrates various examples of a press wheel (e.g.  1100 ) that is contemplated herein and may be used in accordance with the various embodiments and examples disclosed herein. 
       FIG. 15  illustrates a perspective view of a tail section having a closing wheel assembly in accordance with various embodiments. In this embodiment the wheels  1100   a  and  1100   b  are positioned as closing wheels. They are staggered along an articulating bracket similar to those discussed above. The wheels are positioned on either side of a furrow and are angled with respect to the ground. In this way the outer tines, e.g.  1120  engage the soil and churn it pushing the soil into the furrow. The wheels  1100   a  and  1100   b  may be positioned at angles offside from the perpendicular with respect to the ground. The top of the wheels may extend out such that the outside tines point more directly at the soil than the inside tines do. 
       FIG. 16A  illustrates a rear perspective view of a tail section having a closing wheel assembly on a walking arm in accordance with various embodiments. In this embodiment the wheels  1100   a  and  1100   b  are positioned as closing wheels. They are staggered along an articulating bracket  800  with the rear wheel  1100   a  proximal to the rear end  830  of the bracket  800  and the front wheel  1100   b  proximal to the front end  820  of the bracket. The bracket  800  may pivot between the two wheels at pivot  810  which is connected to the body of the trailing arm assembly. The bracket  800  may be similar to those discussed above and those in the application incorporated by reference. The wheels are positioned on either side of a furrow and are angled with respect to the ground. The front wheel may have an angle of W and the rear wheel  1100   a  may have an angle of Z. The angles W and Z may be optimized to so that the outside tines engage the furrow and provide the best seed cover. In this way the outer tines, e.g.  1120  engage the soil and churn it pushing the soil into the furrow. The wheels  1100   a  and  1100   b  may be positioned at angles offside from the perpendicular with respect to the ground. The top of the wheels may extend out such that the outside tines point more directly at the soil than the inside tines do. The bracket  800  may be a part of a parallel linkage as discussed above. 
       FIG. 16B  illustrates a rear perspective view of a tail section having a closing wheel assembly on a walking arm without a fertilizer opening disc in accordance with various embodiments. In accordance with various embodiments, a walking beam  1800  may be configured to keep substantially constant pressure on both press wheels and also keep trash and rocks from making the back of the planter bounce up and down as it travels through the field. The walking beam  1800  may be configured to do this with minimal down pressure. By combining a parallel linkage trailing assembly  300  with a walking beam  1800  bouncing and up draft on the planter units is limited. By staggering the wheels (as shown here the wheel mounting points  1820 ,  1830 ) forward and back of the center pivot  1810 , a better closing action of the seed furrow is created. By having the press wheels separated so that there is minimal or no lateral overlap with one another, the competition between press wheels (i.e. the force they interact on one another) is limited. This allows, the front wheel at connection  1820  can push the soil further across or beyond the center of the furrow and when the back closing wheel at connection  1830  comes along, it pushes the soil back across tying the soil together eliminating or limiting the air pockets and the seam that cause the cracking of the closed furrow. Thus, the furrow does not open in the center of the seed V and exposing seeds. The economic loss of the furrow cracking open in less than ideal weather conditions can be devastating and can lead to having to replant acres or loss of yield at the end of the growing season. The stagger reduces this. This configuration can also reduce premature wear and tear on the bearings, making the life expectancy longer than with traditional closing wheel setups. Additionally, the walking arm  1800  allows less pressure on the planter up front because the pivoting arm is able to climb over debris in the field with its swinging action in conjunction with the four-bar linkage and have less feedback from the debris reach the planter. By providing a walking arm  1800  without a fertilizer disc, the staggered closing wheels at  1830  and  1820  are better balanced for improved performance as shown in  FIG. 16B . 
       FIG. 16C  illustrates the walking arm  1800  having an additional biasing mechanism  1890  suitable to level out the walking arm  1800  when the closing assembly is not on the ground. Specifically, this example shows a walking arm  1800  having a biased axle. As described herein with regards to  FIGS. 16C-16G  the axle may be a solid axle for mounting a bracket thereon, a threaded aperture for receiving a fastener to mount to a bracket, or similar structure allowing the walking arm  1800  to pivot relative to the bracket. The biased axle may include a protrusion or aperture  1920  for mounting to bracket. The protrusion or aperture may form a part of a biasing element such as block  1922 . As shown in  FIG. 16D  the block  1922  may be cylindrical. Whereas, in another example shown in  FIG. 16E  the block  1922  may be more cubic. The block  1922  may be inserted into housing  1910 . One or more biasing elements (e.g.,  1914   a,    1914   b,    1914   c,  and  1914   d  in  FIG. 16D and 1924   a,    1924   b,    1924   c,  and  1924   d  in  FIG. 16E ) and may fit between the block  1922  and the housing  1910 . The fit is a very tight fit that limits or prevents rotation of the block  1922  relative to the housing  1910  except by flexing the biasing elements. In this way the axle  1920  only rotates relative to the housing by flexing the biasing elements. This allows the axle to remain fixed relative to the rest of the trailing arm assembly  300  while the walking arm  1800  rotates relative thereto. However the biasing elements will bias the walking arm  1800  back to its original shape when ground pressure is removed from the wheels attached to the walking arm. The biasing elements may be elastomeric cords that extend through the housing  1910 . For example, the biasing elements may be rubber cords that are about 2-3 inches long in a square tube. The square tube in one example is about 2 inches by 2 inches but may be larger or smaller or other shapes. The axel shaft  1920  can be tapped for a bolt on each end for holding it in place. The biasing elements may be selected to obtain a biasing force that is greater to equal to the weight of implements mounted onto each end of the walking arm  1800 . For example, the biasing elements together may provide a biasing force of between 5 lbs. and 10 lbs. of centering ability. In one example, the walking beam moves up about 2 ½ inches from center and about 2 ½ inches down from center for a total of about 5 inches of overall travel. This torsion assembly can be used to center up the assembly when the planter is raised. 
       FIG. 16F  illustrates another embodiment of the walking arm  1800  having an additional biasing mechanism  1890  suitable to level out the walking arm  1800  when the closing assembly is not on the ground. In this embodiment bout the housing  1910  and a biasing block  1934  are round. A round axle  1920  then fits within the round biasing block  1934 . In this embodiment, an oversized round rubber bushing may be used as the biasing block  1934 . The biasing block  1934  has a metal tube or shaft  1920  molded into it for mounting with an exterior bracket. The shaft  1920  may be the size of bolt with bolt type threads or no threads. Alternatively the shaft  1920  may be a shaft with a hole in the center for a bolt to be threaded into it. This shaft  1920  holds the biasing mechanism in place on the closing assembly  300 . The biasing block  1934  is over sized for the aperture that defines the housing  1910 , which can be a cylindrical shaped tube. The biasing block  1934  is pressed into the housing  1910 . The rubber bushing could be made to flex allowing the shaft  1920  to pivot relative to the housing  1910 , which in turn allows the walking beam to pivot up and down relative to the closing assembly  300  with minimal pressure exerted by the press wheels when engaged in the soil. The pivot bushing gives a range of motion both ways from center when engaged in the soil and then when the planter was picked up it would center itself. The bushing is strong enough to center everything on the walking beam  1800  back up when the planter was raised. 
       FIGS. 16H  and I illustrate a flat spring biasing mechanism for walking beam  1800 . The flat spring  1960  may contact the top of the walking beam  1800  on each side of its pivot. However, the flat spring  1960  may be formed over an offset  1950  such that the pin will not pivot around the same axis as the walking beam  1800 . This allows a first end  1962  of the flat spring to exert a force against the walking beam on a first end when the beam presses into it and also allows the flat spring to exert a force against the walking beam on a second end  1964  when the beam on that side presses into it. The spring may bend up at bends  1968  and  1966  and the fold back at inflection  1961 . This shape places the point the spring  1960  would pivot (i.e. at offset  1950 ) at a point offset from the pivot of the walking beam  1800 . The spring may be support at the offset  1950  by a pin. This spring set up would be like having a balanced teeter totter so it would cause the walking beam  1800  to rest and return to a neutral position when no force is exerted on the beam  1800 . In one example, the flat spring may be from about ½ inch to about ⅝ inch. In one example, the spring is suitable to exert from about 10 pounds to about 12 pounds of pressure to center the walking beam axle. 
       FIG. 16J  illustrates wire spring  1970  biasing mechanism for walking beam  1800 . The wire spring  1970  includes a wire that extends to either side of the walking beam  1800  pivot. One side of the wire spring  1970  has a hook  1974  that retains the top of the walking beam  1800  and the other side of the wire spring  1970  has a hood  1972  that retains the bottom of the walking beam. The middle portion of the wire spring  1970  includes two wire portions  1978  and  1976  that engage either side of an offset  1971 . The offset is positioned above or below the walking beam  1800  pivot. The engagement between the offset  1971  and the two wire portions biases the hook portions of the wire  1974  and  1972 , which in turn biases the walking beam into a neutral position. The spring is sufficiently strong to bias the walking beam  1800  into a neutral position when it is fully loaded with implements such as closing wheels, opening wheels, fertilizer discs or the like. 
     While discussed with respect to the various embodiments discussed herein as two parallel linkage assemblies, it is understood that only the planter may be a parallel linkage assembly, only the closer may be a parallel linkage assembly, both may be parallel linkage assemblies, or in various embodiments employing the various wheel structures discussed herein or other inventive laments as understood from the disclosure provided herein, neither the planter or closer are parallel linkage assemblies. As illustrated in these alternative examples, the various embodiments, aspects, or examples may be variously combined with other embodiments, aspects, or examples of the various inventive concepts disclosed herein. 
     Although various representative embodiments of this invention have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the spirit or scope of the inventive subject matter set forth in the specification and claims. The various embodiments discussed herein are not exclusive to their own individual disclosures. Each of the various embodiments may be combined with or excluded from other embodiments. All directional references (e.g., upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are only used for identification purposes to aid the reader&#39;s understanding of the embodiments of the present invention, and do not create limitations, particularly as to the position, orientation, or use of the invention unless specifically set forth in the claims. Joinder references (e.g., attached, coupled, connected, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. As such, joinder references do not necessarily infer that two elements are directly connected and in fixed relation to each other. 
     In some instances, components are described with reference to “ends” having a particular characteristic and/or being connected with another part. However, those skilled in the art will recognize that the present invention is not limited to components which terminate immediately beyond their points of connection with other parts. Thus, the term “end” should be interpreted broadly, in a manner that includes areas adjacent, rearward, forward of, or otherwise near the terminus of a particular element, link, component, part, member or the like. In methodologies directly or indirectly set forth herein, various steps and operations are described in one possible order of operation, but those skilled in the art will recognize that steps and operations may be rearranged, replaced, or eliminated without necessarily departing from the spirit and scope of the present invention. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the spirit of the invention as defined in the appended claims.