Abstract:
A debris clearing apparatus for use in agricultural operations. It includes a pair of rotatable concave disks arranged in a generally V-shaped orientation to spread debris encountered during forward movement. The disks have a plurality of relatively deep backswept notches.

Description:
This application is a continuation-in-part of application Ser. No. 08/599,082, filed Feb. 9, 1996. 
    
    
     The present invention generally relates to debris clearing apparatus and more particularly relates to row crop debris clearing apparatus for agricultural usage. 
     The increased use of low-till and no-till farming techniques has produced a need for apparatus that can be attached to farm implements for clearing debris such as mulch., plant stalks, and the like from the ground, particularly during planting of a row crop such as corn. It is well known that the optimum emergence of corn plants is a function of the precision with which the corn seeds are planted. It is very important for desired emergence that the seed be planted at a precise depth and spacing during the planting operation. Since the depth of planting of the seed is controlled by rubber wheels of the planter unit, the presence of corn stalks or other mulch or debris in the row line during the planting operation can change the elevation of the wheels and therefore the planter itself. This then affects the depth of planting of the seeds which usually results in poor emergence of the crop. 
     It is also important that debris be cleared from the row line if herbicides are to be applied to the field during planting. It is well known that the herbicide will be less effective if it merely contacts the debris rather than the soil itself. For these reasons, there has been considerable activity in the development of debris clearing apparatus that can be attached to a planter or other implement, which operates to move the mulch and debris out of the path of the planter so that accurate planting can be carried out and effective use of herbicides is achieved. 
     Among the designs that exist are those disclosed in such patents as Williams et al. U.S. Pat. No. 4,425,973, and Martin U.S. Pat. No. 4,785,890, among others. The Martin patent discloses flat, sharply toothed wheels that are arranged in a true “V” to spread the debris that is engaged and move it out of the way of the planting unit in which it precedes. The Williams et al. patent discloses a similar V-shaped orientation for a pair of concave, shallow notched disks. While these designs are effective to a degree, they both exhibit a less than optimum clearing result in that they often exhibit a problem of the engaged debris not being effectively released from the wheels or disks because it tends to wrap on the disk and often ultimately fouls it. This requires the operator to stop his farming operation and remove the debris from the apparatus. 
     Another problem with prior art designs is that the clearing disks interfere with one another. If two clearing disks each contact a single item of debris at the same time, both disks pull the debris in opposite directions. Frequently, this results in the debris plugging up the apparatus or not being removed from the path. 
     Accordingly, it is a primary object of the present invention to provide an improved debris clearing apparatus for use in agricultural applications. 
     It is another object of the present invention to provide such an improved apparatus having a clean and uncomplicated design, which enables it to be manufactured with a relatively few number of parts, but which provides superior operation in clearing debris along a path without fouling. 
     It is another object of the present invention lies in the provision for a unique notch design for clearing disks, which by virtue of the angular orientation of the forward and rearward edges of the notch edges, uniquely utilizes the inertia of the debris as well as gravitational force to optimize the clearing operation and prevent the debris from wrapping on the disks. 
     It is another object of the present invention is to provide such an improved apparatus having a first clearing blade spaced apart from a second clearing disk along a longitudinal cleaning direction of a row path such that the two clearing disks do not interfere with one another by both contacting a common piece of debris. 
    
    
     These and other objects and advantages will become apparent upon reading the following detailed description, while referring to the attached drawings, in which: 
     FIG. 1 is a side illustration of the present invention and is shown together with other farm implements; 
     FIG. 2 is a top view of the application of the present invention; 
     FIG. 3 is a side elevation of the frame portion of the present invention; and, 
     FIG. 4 is a cross-section of a portion of a disk shown penetrating the ground by a distance of about 1 to 2 inches, and particularly illustrating the generally vertical orientation of the penetrating portion. 
    
    
     DETAILED DESCRIPTION 
     Broadly stated, the present invention is directed to a debris clearing apparatus for agricultural operations, and particularly for use in row crop applications such as planting corn or other row crops in a field where debris is usually present from a prior growing season. The apparatus has a simple and clean design and can be inexpensively fabricated, largely using relatively common readily available components. It is easily installed and adjusted to the desired depth and efficiently operates to clear mulch and other debris from the path of a following implement such as a corn planter or the like. 
     Turning now to the drawings, and particularly FIG. 1, the apparatus of the present invention, indicated generally at  10 , is shown attached to a farm implement, which in this embodiment, is a fertilizer applying apparatus  12 . The apparatus  12  is in turn attached to a corn planter, indicated generally at  14 . It should be understood that other implements may profitably utilize the present invention for clearing a path during its operation. In the example shown in FIG. 1, the corn planter  14  has rubber tired wheels  16  which provides the reference surface elevation for planting disks  18  which cut a groove in the earth in which other components (not shown) plant seeds of corn or the like during operation. 
     If the field is full of corn stalks and other mulch, the tires  16  will ride up and down depending upon the thickness of the mulch and this will have an effect on the depth of planting of the seeds by the planter. As previously mentioned, if the planting depth is not correct, the emergence of the crop may be detrimentally affected and productivity of the producer will be decreased. 
     In the embodiment of FIG. 1, the apparatus  10  of the present invention is installed on the fertilizer applying apparatus  12 , which includes a bracket  20  in which a shank portion  22  of the present invention may be inserted. The bracket  20  has bolts or pins  24  which fit within apertures  26  and which can be tightened to hold the shank  22  at the appropriate depth. It should be understood that a farm implement may have many planters for simultaneously planting many rows of crops and for each planting unit, there may be provided a fertilizer unit  12  as well as a debris clearing apparatus  10  embodying the present invention. It is desirable that all of the rows have their implements set at the same depth so that consistency in planting, fertilizer applying and clearing is achieved. In this regard, the shank  22  also has a number of apertures  27  through which the bolts  24  may pass for setting the elevation of various ones of the apparatus  10  at a consistent depth from row to row. 
     The fertilizer applying apparatus  12  is the subject of a patent application entitled “Apparatus For Use In Applying Fertilizer”, Ser. No. 08/593,684, filed Jan. 29, 1996, which is assigned to the same assignee as the present invention and that application is specifically incorporated by reference herein even though it does not form a part of the present invention. Similarly, the planting unit  14  or other implement that may be used in combination with the apparatus of the present invention also does not form a part of the present invention. 
     The structure of the apparatus is relatively simple, and referring to FIGS. 2 and 3, the shank  22  is attached to a frame structure that also includes a support that comprises an elongated flat plate  28 , preferably by welding. The plate  28  is attached to a small front side wall  30  and a longer rear side wall  32 , preferably by welding. The plate  28  has an aperture  33  inside the shank  22  for draining water and the like. The side walls  30  and  32  have apertures  34  for mounting rearward and forward rotatable disks, indicated generally at  36  and  38 , respectively, to the side walls  32  and  30 . The disks are journaled for rotation utilizing a mount structure  39  that has internal bearings attached to axles  44  using a construction that is well known in the art. 
     In accordance with an important aspect of the present invention, the side walls  30  and  32  are preferably angled relative to vertical by about 15 degrees, as shown in FIG.  2 . Such angular orientation of the side walls results in a plane defined by the outer edges of each of the disks being angled relative to vertical, such that the top reach of each disk  36  and  38  extends outwardly farther than the lower reach. Such angular orientation of the disks results in the portion of the disks that penetrate the ground, which is less than about 2 inches, be generally vertical as is desired and as shown in FIG.  4 . It has been found that if the disks are angled more than about 15 degrees, the disks tend to push the trash to the side only a small distance and that the disks often fail to rotate well. Also, if the disks are angled less than 15 degrees relative to vertical, it has been found that the debris is pitched too far from the row path and may interfere with an adjacent row path. 
     As shown in FIG. 2, the disk  38  is mounted to the forward aperture  34 , while the disk  36  is mounted in the rearward one. This, together with different lengths of the front side wall  30  and the rear side wall  32 , enables the forward reach of the disk  38  (marked  40 ) to be ahead of the forward reach of the disk  36  (marked  42 ) by a sufficient distance that the two disks do not interfere with one another in the sense of competing for the same pieces of debris. However, as the apparatus moves forwardly through the field, both forward reaches  40  and  42  are generally on the same line in the direction of movement, so that no debris is missed during operation. 
     Specifically, according to the preferred embodiment of the present invention, the forward reach  40  of the disk  38  is within the range of about 3 to about 10 inches ahead of the disk  36 , and preferably about 4.5 inches. This spacing of the disks ensures that both disks are not interfering with each other by simultaneously engaging a single item of debris. It should be understood that the present invention would work equally well if the positioning of the disks were reversed. It is desirable that for implements that have multiple row or row path apparatus mounted thereon, that a generally equal number of the configurations shown in FIG. 2 be reversed configurations. This produces a balancing of lateral forces that are usually produced when one disk is forward of the other on each apparatus, and minimizes the unwanting sideways movement of the implement produced by the uneven lateral forces. 
     The disk  36  is journaled to axle  44  which is attached to the side wall  32  by attachment through the rearward aperture  34 , and the disk  38  is journaled to axle  46  which is attached to the side wall  30  by attachment through the forward aperture  34  by conventional means not shown. The side wall  32  is longer than the side wall  30  to properly position the forward reaches  40  and  42  relative to one another as shown and previously described. The disks are mounted so that the inner sides are attached to their associated axles and the outer sides are presented for contact for engagement with the debris. It should be understood that the construction of the journals may be such that they fit within an opening in the disk and are therefore technically attached to both sides of the disk. However, for purposes herein, the axles are attached to one of the side walls  30 ,  32  and are on the inside of the disks as shown in the drawings. 
     The outside surface of each of the disks is concave and the generally circular outer periphery of each disk also contains relatively deep backswept notches, indicated generally at  48 , that are spaced from one another around the periphery. While the size of the disks arc not critical, they are preferably at least 13 inches in diameter and may even be up to about 20 inches in diameter in some applications. A major consideration in having larger sized disks is the clearance requirements of the apparatus in relation to other components of other implements, including drive shafts and the like. Also, while the number of notches in each disk is not particularly critical, it is preferred that there be at least nine and preferably about 12 of such notches per disk for a disk diameter of about 13 inches. The depth of the notches, while also not particularly critical, should be deeper than the shallow notches disclosed in the aforementioned Williams et al. patent, and are preferably at least 1¾ inches deep from the outermost diameter of the disk to the deepest point of the notch. If the disk size is larger, i.e., approaching the 20″ diameter, it is preferred that the number of notches be increased proportionately, and that the depth of the notches stay about the same. Thus, a 20″ diameter disk would preferably have about 20 notches of 1¾″ depth. 
     In accordance with an important aspect of the present invention, and as best shown in FIG. 1, the configuration of the notches  48  is extremely important in the superior operation of the present invention and cach of the notches  48  has a forward edge  50  and a rearward edge  52 . The forward edge  50  is preferably slightly curved but is oriented generally in the radial direction from the outer periphery to the deepest point of the notch, where it meets the rearward edge  52  which extends to the outer periphery at a much different angle that is more tangential than radial. In this regard, the angle between the forward and rearward edges  50  and  52  is preferably within the range of about 50° to about 70° and in the preferred embodiment is about 60°. 
     As shown in FIG. 1, the forward edge  50  is the edge of the notch that first engages the ground during rotation during movement of the implement in the forward direction, as shown by the arrow marked FWD. As the forward edge  50  engages the ground, the disk  36  will tend to move clockwise as shown in FIG. 1, so that as the forward edge  50  begins to move out of contact with the ground, the rearward edge  52  is the last edge to lose contact with the ground and as the disk continues to rotate, the orientation of the rearward edge  52  is generally vertical as shown at location  54  in FIG.  1 . This is important in minimizing the tendency for debris to wrap on the disk and this occurs because with the vertical orientation, there is very little resistance holding the debris on the disk as it begins to move away from the ground. 
     The combined effect of inertia which will tend to separate the debris from the rotating disk and gravitational forces acting on the debris coupled with the absence of any retaining surface of the disk tend to result in the material being passed aside as is desired. It is also important to note that the concavity of the outside of the disks and the use of inertia also contributes to the separation of the mulch and other debris and cast it aside as is desired. 
     The apparatus is preferably set so that the disk does contact and move the dirt and no attempt is made to minimize the tilling of the dirt, for that is believed to be desirable. It has been found that minimum tilling of the dirt tends to contribute to the separation of the dirt from the mulch and the combination of the configuration of the notches  48  with the concavity of the disks results in superior operation in clearing the debris without experiencing undesirable wrapping. 
     While various embodiments of the present invention have been shown and described, it should be understood that other modifications, substitutions and alternatives are apparent to one of ordinary skill in the art. Such modifications, substitutions and alternatives can be made without departing from the spirit and scope of the invention, which should be determined from the appended claims. 
     Various features of the invention are set forth in the appended claims.