Abstract:
A ground opener that is allowed to caster in one direction is associated with a pair of arms connected by a pivot connection that allows one arm to move relative to the other arm. The movable arm is forced against the stationary arm when the ground opener impacts the soil as the ground opener is pulled along a relatively straight travel path. When the ground opener is turned radially from the straight travel path, the movable arm may cast away from the stationary arm. The disc opener is coupled to the movable arm through a central hub and, as such, the trailing edge of the disc opener will move away from the stationary arm as the disc opener is turned. When the disc opener has completed the turn, the torque on the disc opener will lessen thereby allowing the movable arm to move back toward the stationary arm.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to agricultural implements, and in particular, to a seed planting unit having disc reels that can freely caster in one direction. 
   BACKGROUND OF THE INVENTION 
   Conventional seed planting systems includes a series of spaced coulters or reels that prepare a seed bed and deposit seed into the seed bed as the seed planting system is pulled, by a tractor, for example, along a relatively straight path of travel. Customarily, when it is necessary to turn from the straight travel path, a lift mechanism must be operated to lift the coulters above the ground so that damage is not caused to the coulters during the turning. Once the seed planting system is realigned with the straight travel path, the lift mechanism can be operated to lower the coulters to the ground. 
   The need to lift the coulters during radial turns from the straight travel path is necessary to avoid the torque that would be applied on the coulters by the ground if the coulters were otherwise left engaged with the ground during turning. More particularly, conventional coulters are constructed to have a fixed position generally angled relative to an axis extending along the straight travel path. When the seed planting system turns, the leading edge of the coulter initially scrapes across the ground and then may effectively dig into the ground. This can place a significant amount of torque on the coulters and significantly stress the coulter or the coupling used to connect the coulter to the disc frame. 
   SUMMARY OF THE INVENTION 
   The present inventors have discovered that the torque placed on a coulter or ground opener may be alleviated if the coulter is free to pivot or caster in a direction opposite the direction of the applied torque during turning of the seed planting system. In this regard, the present invention is directed to a ground opener that is allowed to caster in one direction. The ground opener is associated with a pair of arms connected by a pivot connection that allows one arm to move relative to the other arm. The movable arm is generally forced against the stationary arm by the impact of the ground opener with the soil as the ground opener is pulled along a relatively straight travel path. When the ground opener is turned radially from the straight travel path, the pivot connection effectively serves a fulcrum against which the disc opener is leveraged. To relieve the torque, the movable arm may cast away from the stationary arm. The disc opener is coupled to the movable arm through a central hub and, as such, the trailing edge of the disc opener will move away from the stationary arm as the disc opener is turned. When the disc opener has completed the turn and returns to a generally straight travel path, the torque on the leading edge of the disc opener will lessen thereby allowing the movable arm to move back toward the stationary arm. 
   In one embodiment, the stationary arm carries a stud that extends toward the movable arm and thereby provides a seat for the movable arm when the disc opener is moving along the straight travel path. Additionally, the stud prevents the disc opener from casting toward the stationary arm. Thus, in this embodiment, the disc opener is free to cast in only one direction. 
   It is contemplated that the stud may be of fixed length or may be screw that is threaded through the stationary arm. Use of a screw or similar device allows some variability in the amount of caster that is possible. More particularly, as the distance the body of the screw extends past the stationary arm and toward the movable arm increases, the amount of caster possible for the movable arm and thus the disc opener is reduced. 
   In another embodiment, the present invention is directed to a seed planting assembly having multiple disc openers arranged in a row. The disc openers are arranged such that two sets of disc openers are provided. One set of disc openers are designed to caster only in a clockwise direction and the other set of disc openers are designed to caster only in a counterclockwise direction. 
   Accordingly, one object of the present invention is to provide a disc opener that is free to cast to reduce torque on the disc opener during radial turns from a straight travel path. 
   It is a further object of the present invention to provide a caster mounting assembly that allows variability in the amount of caster available to the disc opener during radial turns. 
   It is yet another object of the present invention to incorporate disc openers that are permitted to caster in only one direction into a seed planting assembly such that some of the disc openers are free to cast in one direction whereas others of the disc openers are free to caster in an opposite direction. 
   Therefore, in accordance with one aspect of the present invention, a ground opener for an agricultural planter movable along a direction of travel is presented. The ground opener includes an arm attachable to a frame of the agricultural planter and a disc mounted to the arm and adapted to form a furrow along the direction of travel. The ground opener further includes a stop pivotably mounted to the frame and adapted to allow the disc to caster in only one direction when the agricultural planter turns radially from the direction of travel. 
   In accordance with another aspect, an agricultural implement movable along a direction of travel includes a drill and a first set of coulters mounted to the drill and a second set of coulters linearly spaced from the first set of coulters and mounted to the drill. The first set of coulters are operative to caster in a counterclockwise direction when the farm implement turns in a counterclockwise direction relative to the direction of travel and the second set of coulters are operative to caster in a clockwise direction when the agricultural implement turns in a clockwise direction relative to the direction of travel. 
   According to yet another aspect, the present invention includes a mounting assembly for coupling a rotating disc to a drill used to furrow a field. The mounting assembly includes a stationary arm adapted to be coupled to the drill and a movable arm adapted to be coupled to the rotating disc. A pivot connection interconnects the stationary arm and the movable arm in a manner that allows the movable arm to pivot about the first connection. 
   Other objects, features, and advantages of the invention will become apparent to those skilled in the art from the following detailed description and accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the present invention without departing from the spirit thereof, and the invention includes all such modifications. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings in which like reference numerals represent like parts throughout. 
     In the drawings: 
       FIG. 1  is a schematic perspective view of a seed planting assembly supporting a plurality of seed planting units constructed in accordance with a preferred embodiment of the invention; 
       FIG. 2  is a side elevation view of a seed planting unit illustrated in  FIG. 1 ; 
       FIG. 3  is a section view of the seed planting unit taken along lines  3 - 3  of  FIG. 2 ; 
       FIG. 4  is a section view similar to that of  FIG. 3  showing casting of a disc opener in one direction; 
       FIG. 5  is a schematic representation of a clockwise caster of some of the disc openers of the seed planting unit in response to a clockwise turn of the seed planning unit; and 
       FIG. 6  is a schematic representation of a counterclockwise caster of some of the disc openers of the seed planting unit in response to a counterclockwise turn of the seed planning unit. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIG. 1 , a seed planting assembly  10  includes a laterally extending toolbar  12  connected at its middle (or other location) to a forwardly extending tow bar  14 . Tow bar  14  includes a connector  16  disposed at its longitudinally forward end and configured to mate with a corresponding hitch, or the like, of a towing tractor (not shown). Toolbar  12  is supported by a chassis  18  that is connected to tow bar  14  via a hinged bracket assembly  20 . Chassis  18  is supported on the ground by two pair of wheels  22 . Outer portions of tool bar  12  are supported by outer wheels  24  having an adjustable height to thus control the height of the toolbar  12 . 
   A plurality of seed planting units (or row units)  26  extends longitudinally rearwardly from toolbar  12 . In particular, referring also to  FIG. 2 , each planting unit  26  includes a frame  28  that is connected at its front end  30  to toolbar  12  via a mounting assembly  32 . Mounting assembly  32  includes a pair of upper support beams  34  (one illustrated) and a pair of lower support beams  36  (one illustrated) that are hingedly connected to frame or drill  28  at one end, and to a mounting structure  38  at another end. Mounting structure  38  is, in turn, connected to tool bar  12 . 
   Frame  28  defines a front end  30  having a first pair of aligned apertures (not numbered) extending laterally therethrough. Corresponding apertures (not numbered) extend through the rearward ends  40  of each upper support beam  34 . A pin  42  extends through each pair of aligned apertures, and is fastened to provide a joint  44  that enables planting unit  26  to pivot about mounting assembly  32 . 
   Likewise, the front end  30  of frame  28  defines a second pair of laterally extending apertures (not shown) disposed below the first pair of apertures. The second pair of apertures is laterally aligned with corresponding apertures (not shown) extending laterally through the rearward ends  46  of each lower support beam  36 . A pin  48  extends through each pair of aligned apertures and is fastened to provide a joint  50  that enables planting unit  26  to pivot about mounting assembly  32 . 
   Each upper support beam  34  further defines a forward end  52  that defines corresponding apertures (not shown) extending laterally therethrough. Likewise, each lower support beam  36  defines a forward end  54  that defines apertures (not shown) extending laterally therethrough. Mounting structure  38  extends rearwardly from tool bar  12 , and defines laterally extending apertures (not shown) that are aligned with the apertures extending through forward ends  52  and  54 . Upper and lower pins  56  and  58  extend through the corresponding apertures and form corresponding joints  60  and  62  that pivotally connect the forward ends  52  and  54  of support beams  34  and  36  to mounting structure  38 . 
   It should thus be appreciated that while the right-hand side of mounting assembly  32  (taken with respect to a view from rear-to-forward) is illustrated as being mounted onto the right-hand laterally outer walls of frame  28 , the left-hand side of mounting assembly  32  is likewise mounted onto the left-hand laterally outer walls of frame  28  in a symmetrical and parallel manner with respect to the right-hand side of the mounting assembly. Accordingly, while the left support beams  34  and  36  are connected to the left side of planting unit  26  and mounting structure  38  such that both pairs of beams  34  and  36  are parallel to each other during operation. 
   As is well-known in the art, planting units  26  are mounted in a side-by-side (lateral) relation relative to each other along the toolbar  12 . While sixteen such row units are illustrated in  FIG. 1 , the present invention contemplates that more or less than sixteen row units can be assembled on a single toolbar  12  in accordance with a preferred embodiment. During operation, forward movement of the tractor causes row units  26  to ride along the ground, forming a plurality of seed trenches that receive seeds and are subsequently closed. 
   Referring again to  FIG. 2 , each planting unit  26  preferably includes a conventional seed trench opening assembly  64 , each of which including a pair of laterally spaced seed trench opener discs  66  (also referred to as reels or coulters) that converge forwardly and downwardly to define a convergence point  68 . A seed trench firming point  70  is disposed rearwardly from convergence point  68 , and an opener shoe  72  is disposed rearwardly from seed trench firming point  70 . Firming point  70  preferably extends slightly downwardly from the opener shoe  72 , and firms the seed trench that is formed by convergence point  68 . Firming point  70  and opener shoe  72  are preferably integrally connected. The depth of the seed trench can be controlled by a pair of gauge wheels (not shown) that are supported by gauge wheel arms  74  as understood by those having ordinary skill in the art. Alternatively, the planting unit  26  can be provided with a runner opener type for providing a seed trench in the ground as is appreciated by one having ordinary skill in the art. Planting unit  26  further includes a pair of seed trench closer discs  76  disposed rearwardly from opener shoe  72 . A press wheel  78  is disposed rearwardly from closure discs  76 . 
   A pair of screw and spring assemblies  80  (one shown) is displaced laterally from each other and extends downwardly from a first support member (not shown) extending laterally between the upper support beams  34  to a second support member (not shown) extending laterally between the lower support beams  36 . Assemblies  80  are angled with respect to support beams  34  and  36 , and can thus be actuated in a known manner to increase and decrease the down pressure exerted onto seed trench opening assembly  64  to control downward force on the opening discs  66 , as is well understood by those having ordinary skill in the art. A knob  82  extends rearwardly from frame  28 , and can be rotated to adjust the depth of gauge wheels (not shown) which control the desired seed trench depth as appreciated by one having ordinary skill in the art. 
   Planting unit  26  further includes a seed hopper  84  that provides storage for seed material that is to be gravitationally deposited into the seed trench that is formed as the seed trench opening assembly  64  moves across the field during operation. It should be appreciated, however, that a hopper container, smaller than container  84 , can alternatively be connected to a centralized bin or large hopper in a conventional manner. In the illustrated embodiment, seeds are delivered from seed hopper  84  to a seed metering assembly  86  that acts under vacuum received by connector  88 . The received seeds are then delivered into a seed tube  90  at a uniform rate. Seed tube  90  defines a conduit having an outlet end immediately downstream of firming point  70  and upstream of seed trench closer discs  76 . Seed tube  90  thus receives seeds from metering assembly  86  and defines a substantially vertical passage through which the seeds are delivered through the opener shoe  72  and into the seed trench. The components of seed metering assembly  86  are further described in U.S. Pat. No. 6,109,193, the disclosure of which is hereby incorporated by reference. In a similar manner, seed hopper  84  may also be used to deposit fertilizer to the seed bed. Alternately, a separate hopper (not shown) containing fertilizer may be used. 
   During operation, as the tractor pulls the tool bar  12  across and over the ground, the seed trench opening assembly  64  opens a seed trench in the ground. Seeds from the hopper  84  flow into the seed metering assembly  86  in bulk and are subsequently deposited into the seed trench via seed delivery tube  90  at a controlled rate. The seed trench closer discs  76  trail the seed trench opening assembly  64  and, as the seed planting unit  26  is drawn across the field, close the seed trench together and over the seed dispensed by the seed metering assembly  86 . The trailing press wheel  78  compacts the soil closed over the delivered seeds. 
   Planting unit  26  can also be equipped with a pesticide hopper  92  that is mounted towards a rear end of the planting unit. Hopper  92  preferably includes an insecticide and is provided with conventional dispensing apparatus for applying controlled amounts of insecticide where desired in combination with the planting of seeds by each planting unit  26 . 
   Referring again to  FIG. 1 , each planting unit  26  can be coupled to an air moving system  94  that includes one or more air moving units (collectively identified as  96 ) enclosed in one or more housings (collectively identified as  98 ). While air mover unit(s)  96  is configured to provide negative pressure, they can alternatively function as blower units if a positive pressure seed metering assembly is implemented in planting units  26 . Air moving system  94  includes a lower lateral tubing member  100  that is connected at its middle to one of the air moving units  96 , and extends laterally outwardly therefrom in both directions. A plurality of openings (not shown) are formed in tubing member  100  that connect to a forward end of a corresponding plurality of flexible intake tubes that, in turn, connect with the corresponding metering assembly connector  88 . 
   A bifurcated arrangement is illustrated with respect to a pair of upper lateral tubing members  102  that are connected at their laterally inner ends to one or more air mover units  96 . Tubing members  102  extend parallel to, and are disposed above, tubing member  100 , and are connected at their outer ends to outer tubing members  104 . Outer tubing members  104  are vertically aligned with lower tubing member  100 , and extend across those planting units  26  that are disposed laterally outwardly with respect to lower tubing member  100 . A plurality of openings (not shown) are formed in tubing members  104  that connect to a plurality of flexible intake tubes that, in turn, connect with the corresponding metering assembly connectors  88  of laterally outwardly disposed planting units  26 . 
   During operation, air moving units  96  draw air through the metering assemblies  86  of all planting units  26  to which the lateral tubes  100  and  104  are operably connected. The number of air mover units  96  implemented in a given seed planting assembly depends largely on the number of planting units  26  and the airflow rating of each air mover unit. 
   The present invention recognizes that certain seed types (for example, soybeans) are well suited to be planted in seed trenches that are laterally spaced a distance equal to the distance between adjacent seed trench opening assemblies  64  of all planting units  26  disposed on tool bar  12 . However, in order to accommodate other seed types (for example, corn) that require additional distance between adjacent seed trenches in order to grow properly, it is necessary, from time to time, to raise certain planting units  26  above the ground  106 . 
   It should thus be appreciated that the term “raised position” as used in the present application refers to a position whereby planting unit  26  has been translated upwardly to a height sufficient to cause at least the corresponding seed trench opening assembly  64  (and preferably closer disc  76  and press wheel  78 ) to become suspended above the ground  106 . Accordingly, raised planting units  26  will not form a seed trench in the ground  106  when the seed planting assembly  10  is driven across the ground  106 . In one preferred embodiment, alternating planting units can be raised from the ground  106 , thereby doubling the distance between adjacent seed trenches compared to the distance that is achieved when all planting units are engaged, such as described in U.S. Pat. No. 7,111,566, the disclosure of which is incorporated herein. Additionally, each planting unit  26  may include a vertical positioner assembly and associated linkages such as described in U.S. Pat. No. 7,111,566 to raise and lower the planting unit. 
   Referring now to  FIG. 3 , a disc opener  66  is shown coupled to a caster mounting assembly  108  that allows the disc opener  66  to caster freely in a single direction. The caster mounting assembly  108  includes a stationary arm  110  coupled to a movable or castering arm  112  by a pivot connection  114 . The stationary arm  110  is connected to a disc frame or drill  116  that is secured to the planting unit in a conventional manner. The stationary arm  110  may be secured to the disc frame  116  using one a number of known devices, such as a connector bracket or weld joint. 
   The movable arm  112  is coupled to shaft  116  extending centrally through the disc opener  66  and coupled to a center hub  118 . In a preferred embodiment, the disc opener  66  is angled by approximately five to seven degrees relative to axis  120 . The disc opener  66  also carries a scraper blade  122  mounted opposite of hub  118  as is known in the art. As is also known, the seed tube  90  extends between the scraper blade  122  and the disc opener  66  such that seed, fertilizer or other product is delivered into a trench through outlet  124 . 
   In a preferred embodiment, the caster mounting assembly  108  includes a screw  126  extending through stationary arm  110 . The screw  126  has a threaded body  128  extending from head  130 . The stationary arm  110  has a threaded bore  132  adapted to securely receive the screw  126  when the threaded body  128  is threaded therein. The threaded body  128  terminates in a flat end  130  against which the movable arm  112  may seat. Moreover, since the screw  126  has a threaded body  128 , the amount of body extending past the stationary arm  110  toward the movable arm  112  can be varied. This effectively allows for variations in the angle of the disc opener  66  relative to axis  120 . More particularly, the greater the amount of threaded body  128  extending past the stationary arm  110 , the larger the offset of the disc opener  66  relative to axis  120 . 
   The stationary arm  110  and the movable arm  112  are oriented such that the pivot connection  114  is forward of hub  118  relative to the direction of travel  127 . The pivot connection  114  and its position allows the movable arm  112  to caster away from the stationary arm  110  when the seed planting assembly  10  turns counterclockwise from the direction of travel  127 . More particularly, when the seed planting assembly  10  turns counterclockwise the leading edge  128  of the disc opener  66  will drive into the soil and the torque placed on the leading edge  128  will be countered by movement of the movable arm  112  away from the stationary arm  110 , as indicated by arrow  129 , to relieve the torque applied on the disc opener  66 , as illustrated in  FIG. 4 . The greater the angle of the disc opener  66  relative to axis  120 , the greater amount of caster that will be available during turning of the seed planting assembly  10 . 
   In one application, a seed planting unit  10  will have two sets of disc openers. More particularly, as shown in  FIG. 5 , the seed planting unit  10  may have a first set  134  of disc openers operative to caster in a clockwise direction and a second set of disc openers  136  operative to caster in a counterclockwise direction. The disc openers are mounted to a disc frame or drill  138 . As schematically illustrated, when the seed planting unit  10  turns clockwise, shown by arrow  140 , about turning point  142 , the disc openers of the first  134  each caster clockwise. The degree of caster of the disc openers increases with those disc openers farthest from the center  144  of the drill  138 . 
   The second set  136  of disc openers are designed to caster in a counterclockwise direction and thus do not caster when the seed planting unit turns clockwise. Since these disc openers are farthest from the turning point  142 , they will have a larger turning radius than disc openers of set  134 . As a result, the amount of torque on set  136  is less than that on set  134 . 
   Similarly, when the seed planting unit  10  makes a counterclockwise radial turn, as represented by arrow  146 , so as to turn about turning point  148 , the set  136  of disc openers will caster in a counterclockwise direction whereas the set  134  of disc openers will not caster. Since the disc openers of set  134  are farthest from the turning point  148 , they will have a larger turning radius than disc openers of set  136 . As a result, the amount of torque on set  134  is less than that on set  136 . The degree of caster of the disc openers of set  136  increases with those disc openers farthest from the center  144  of the drill  138 . 
   Therefore, in accordance with one embodiment of the present invention, a ground opener for an agricultural planter movable along a direction of travel is presented. The ground opener includes an arm attachable to a frame of the agricultural planter and a disc mounted to the arm and adapted to form a furrow along the direction of travel. The ground opener further includes a stop pivotably mounted to the frame and adapted to allow the disc to caster in only one direction when the agricultural planter turns radially from the direction of travel. 
   In accordance with another embodiment, an agricultural implement movable along a direction of travel includes a drill and a first set of coulters mounted to the drill and a second set of coulters linearly spaced from the first set of coulters and mounted to the drill. The first set of coulters are operative to caster in a counterclockwise direction when the farm implement turns in a counterclockwise direction relative to the direction of travel and the second set of coulters are operative to caster in a clockwise direction when the agricultural implement turns in a clockwise direction relative to the direction of travel. 
   According to yet another embodiment, the present invention includes a mounting assembly for coupling a rotating disc to a drill used to furrow a field. The mounting assembly includes a stationary arm adapted to be coupled to the drill and a movable arm adapted to be coupled to the rotating disc. A pivot connection interconnects the stationary arm and the movable arm in a manner that allows the movable arm to pivot about the first connection. 
   While the present invention has been described with respect to a seed planting unit, it is understood that the invention could be used with other agricultural implements. 
   Many changes and will modifications could be made to the invention without departing from the spirit thereof. The scope of these changes will become apparent from the appended claims.