Patent Abstract:
A knife opener includes a pair of flared blades designed to cut spaced, but paired furrows. The knife opener is particularly well-suited for use in no-till or minimum-till agricultural operations primarily in conjunction with seed and/or fertilizer placement adjacent a soil cut-line generally in the direction of travel. In addition to being angled away from the main body of the knife, one of the blades is angled forward and the other blade is angled rearward. Seed and/or fertilizer dispensing receivers may be associated with each of the blades.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is a continuation application of U.S. Ser. No. 12/203,269, filed Sep. 3, 2008 now abandoned. 

   BACKGROUND OF THE INVENTION 
   The present invention relates to knife opener which may be used as part of no-till or minimum-till farming practices primarily for placement in the ground of seed and/or fertilizer and other materials. 
   Important advantages have been found in soil preparation, and seed and fertilizer delivery in employing no-tilling or minimum tilling methods which cause minimum disturbance to the soil. This is particularly important in drier soil conditions where the soil is subject to moisture and topsoil loss if conventional tilling methods are used. It is usually desirable when employing no-till farming practices to disturb the soil surface as little as possible. The surface will be covered with the residue from previous crops, and the surface layer will contain old root structure. This plant material can serve to retain moisture below the surface and to assist in securing the soil against runoff and erosion. 
   Fertilizer is commonly used to improve crop yields. Broadcasting the fertilizer on the surface is a method that does not disturb the surface, but it can be inefficient as much of the fertilizer can be lost due to runoff surface water. As such, a number of soil bed preparation tools have been developed that are designed to place fertilizer directly in the soil. An example of such a device is a double shoot air drill which enables seed and fertilizer to be deposited as a knife, coulter or other device is towed through the soil. 
   Zero till or minimum till devices have been developed to deposit high concentrations of fertilizer in the furrows formed by the knife or other furrowing tool. If the seed is placed in close proximity to a high concentration of fertilizer, burning of the newly germinated plant can result. Thus, with higher fertilizer concentrations, it is generally desired to space the fertilizer from the seed, either laterally and/or vertically. 
   As noted above, one type of furrow opening tool is a knife. To achieve adequate separation either vertically or horizontally with a knife has required the knife to occupy a relatively large amount of space either in the soil or above the soil. In the case of the former, the knife opens a relatively large furrow thereby resulting in greater soil disturbance. In the case of the latter, the flow of residue around the knife can be impeded. 
   If the flow of residue is impeded that residue tends to collect around the knife and is dragged with the knife as the implement is towed. Not only can this residue collection impair operation of the implement, it also removes the desired moisture retaining cover that may be provided by the residue. 
   Another type of furrowing device is a coulter or disk opener. While disk openers have the ability to cut through most residue, some crop residue, such as straw, may not cut easily, and as a result may be pushed into the furrow, a result commonly called hair-pinning. This can displace seeds, as well as drying out the seed bed. Additionally, effective no-till disc openers can be quite costly. 
   Thus, there remains a need for a knife opener that cuts a furrow with reduced soil disturbance yet provides the desired spacing for higher concentrations of fertilizer. There is also a need for such a knife opener which provides tilling and/or seeding, fertilizing, or weed clearing in a single pass without significant trash accumulation. 
   SUMMARY OF THE INVENTION 
   The invention provides a ground opening knife for use in no-till or minimum-till farming operations primarily in conjunction with seed and/or fertilizer placement adjacent a soil cut-line generally in the direction of travel. The knife opener has a pair of cutting members or blades flared in opposite directions from one another relative to a vertical axis of the knife. In addition to be angled away from the main body of the opener, one of the cutting members is angled forward of the main body. Conversely, the other cutting member is angled rearward of the main body. These forward and rearward cutting members are designed to cut respective furrows into which seed and/or fertilizer may be deposited. As such, in one embodiment, respective product dispensing tubes are mounted to the opener and are designed to deposit particulate matter, such as seed and fertilizer, in the furrow as the cutting members cut through the soil. 
   The invention also provides a no-till or minimum-till farm implement primarily for use in conjunction with cultivation or materials placement adjacent a plurality of soil cut-lines generally parallel and in the direction of travel comprising a support frame structure, a plurality of ground opening knives attached to the support structure spaced from each other in a direction transverse to the direction of travel of the implement and each adapted to cut the soil along adjacent cut-lines. Each knife has a pair of flared cutting members. 
   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 FIGURES 
     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 side elevation view of an agricultural implement incorporating knife openers according to one embodiment of the present invention; 
       FIG. 2  is an isometric view of a knife opener for use with the implement shown in  FIG. 1  according to one embodiment of the present invention; 
       FIG. 3  is a front elevation view of the knife opener shown in  FIG. 2 ; and 
       FIG. 4  is a side elevation view of the knife opener shown in  FIG. 2 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows an air hoe drill  10  designed to form multiple furrows in a surface, e.g., farm field, and deposit seed and/or fertilizer in the furrows. The air hoe drill  10  is representative of one type of agricultural implement with which the present invention may be used. Generally, the drill  10  includes a frame  12  coupled in a known manner to a tow bar  14  that facilitates attachment of the frame  14  to a tractor (not shown) or other towing vehicle. The frame  12  is supported above the planting surface S by a series of forward wheels  16  and rear packing wheels  18 . As known in the art, the packing wheels  18  not only support the frame  12  but also serve to pack the furrows after seed and/or fertilizer has been deposited. In this regard, the packing wheels  18  are aligned with a series of knife openers  20  that are mounted in a known manner to the frame  12 . The depth of the knife openers  20  can be set and adjusted by raising and lowering the frame  12  relative to the wheels  16 ,  18  as known in the art. In one representative embodiment, the knife openers  20  are equally spaced from one another in a direction transverse to the path of travel of the drill  10 . The drill  10  further includes an air cart  22  that includes a tank  24  for carrying seed and/or fertilizer. The particulate is fed from the tank  24  to the furrows using seed tubes  26  that are associated with the knife openers. One skilled in the art will appreciate that the air hoe drill shown in  FIG. 1  is merely representative of one type of agricultural implement that can incorporate the present invention. For example, the invention may also be applicable with a precision air hoe drill where the frame is supported by a set of forward wheels and a set of rearward wheels, and having a series of trailing arms and/or parallel links to which knife openers such as those described herein may be substantially attached together with packer wheels. 
   Referring now to  FIG. 2 , a representative knife opener  20  according to the present invention is shown. While a single knife opener  20  will be described, it is appreciated that the other knife openers of the drill  10  shown in  FIG. 1  are similarly constructed. The knife opener  20  includes a shank  26  which may be mounted to the frame  12  in a known fashion. The shank  26  preferably has a pair of holes  28  adapted to receive fasteners (not shown), e.g., mounting bolts, for attaching the knife opener  20  to the frame  12 . 
   Knife opener  20  includes a forward biased blade  30  formed to penetrate the soil along a soil-cut line oriented in the direction of travel. Knife opener  20  further includes a rearward biased blade  32  that is formed to penetrate the soil along a separate soil-cut line oriented in the direction of travel. Each of the blades  30 ,  32  is flared away from the shank  26  and, as such, each blade penetrates the soil along respective, but generally parallel soil-cut lines. In this regard, the soil-cut lines are paired with one another but spaced to accommodate a desired spacing between fertilizer and seed. 
   Adjacent the respective backsides of blades  30 ,  32  are seed tube receivers  34 ,  36 , respectively. Receiver  34  has an inlet  38  adapted to receive a seed tube or hose (not shown) that is fluidly linked with the tank  24  of the air seeder  22 . The receiver  34  further has an outlet  40  or mouth that is disposed generally behind blade  30 . Particulate matter is fed, generally by forced air, from the tank through the seed tubes to the outlet  40  whereupon the matter is deposited in the furrow created by blade  30 . Similarly, receiver  36  has an inlet  42  adapted to receive a seed tube or hose (not shown) that is fluidly linked with the tank  24  of the air seeder  22 . The receiver  36  has an outlet  44  or mouth that is disposed generally behind blade  32 . Particulate matter is fed, generally by forced air, from the tank through the seed tube to the outlet  44  whereupon the matter is deposited in the furrow created by blade  32 . The receivers  32  and  36  are placed such that the respective outlets  40  and  44  are generally in plane with the lowermost surfaces of blades  30  and  32 , respectively. Placement of the receivers behind the blades also serves to protect the receivers, and the seed tubes received therein, from damage during the seeding or fertilizing process. 
   As described above, blades  30  and  32  are flared relative to shank  26 , as further illustrated in  FIG. 3 . In one representative embodiment, the shank  26  has an upper portion  26   a  and a lower portion  26   b  that are joined together by an angled portion  26   c . The lower portion  26   b  generally extends about a vertical axis  46  and the blades  30 ,  32  extend downwardly from the lower portion  26   b  and angled relative to the vertical axis  46 . As shown in  FIG. 4 , the profile of the lower portion  26   b  has an inwardly angled portion  26   b ′ and an outwardly angled portion  26   b ″; however, it is understood that the invention is not so limited. For example, in one alternate embodiment the lower portion  26   b  is faceted such that the leading edge of lower portion  26   b  is curved. 
   In one preferred embodiment, the inside edge  48  of blade  30  is angled relative to the vertical axis  46  at angle of approximately 25 degrees; but it is understood that the blade  30  could be formed to extend at other angles. However, it is generally preferred that the angle α be between approximately 15 degrees and approximately 60 degrees. Blade  32  is angled relative the vertical axis, as defined by its inner edge  50 , at a preferred angle α of 30 degrees but it is understood that the blade  32  could be formed to be angled at other angles. However, it is generally preferred that the angle β be between approximately 15 degrees and approximately 60 degrees 
   Referring now to  FIG. 4 , in addition to its flared orientation, shanks  30  and  32  are also biased in a forward direction and a rearward direction, respectively. More particularly, the backside of the shank generally defines a vertical axis  50  and the angle γ defined between the vertical axis  50  and the leading edge  52  of the blade  30  is preferably approximately 35 degrees, but other angular orientations are possible. Preferably, the angle γ is between approximately 15 degrees and approximately 60 degrees. As illustrated in  FIG. 4 , the leading edge  52  of blade  30  has a tip portion  54  and the angle γ is measured between the tip portion  54  and the vertical axis  50 . 
   As illustrated in  FIG. 4 , preferably the cutting edge  52  of blade  30  is significantly in advance of the lower portion  26   b  of the shank  26 . Deeper soil is cut and lifted in advance of cutting the surface soil allowing the surface to be cut more easily and without undue lateral disruption. In addition, vertical motion is limited. Moreover, the blade  30  cuts through the surface and trash layers without accumulating trash on the shank  26 . 
   The rearward extending blade  32  also has a leading edge  56  and the leading edge  56  extends along an imaginary axis  58  that is angled relative to the vertical axis  50  at an angle δ. In one preferred embodiment, the angle δ is approximately 60 degrees; however, other angles are possible. It is generally preferred however that the angle δ fall between approximately 15 degrees and approximately 75 degrees. 
   As further illustrated in  FIGS. 3-4 , in a preferred embodiment, the bottom edge  60  of blade  30  sits lower than the bottom edge  62  of blade  32 . Thus, blade  30  cuts a furrow that is deeper than the furrow cut by blade  32 . This allows a stratification in the vertical plane of seed and fertilizer in the paired furrows. It is appreciated however that the blades  30 ,  32  could be oriented so that the bottom edges  60 ,  62  are in the same plane and thus cut furrows of substantially the same depth. 
   In one representative embodiment, the width of the furrow cut by blade  30  is the same as that cut by blade  32 , but it is contemplated that the blades  30 ,  32  could be sized such that different sized furrows are cut. 
   Referring again to  FIG. 4 , not only are the blades  30  and  32  flared with respect to vertical axis  46  and angled with respect to vertical axis  50 , the blades also have respective pitch angles or “rake angles”. In a preferred embodiment, blade  30  has a rake angle ε between approximately 0 degrees and approximately 15 degrees, and preferably 2 degrees. Similarly, blade  32  has a rake angle θ between approximately 0 degrees and approximately 15 degrees, and preferably 2 degrees. 
   The flared blades  30 ,  32  are designed such that each blade temporarily lifts a flap of soil then the flaps are lowered gently back after the knife opener is passed. Seed and/or fertilizer is deposited and is preferably covered as the flap settles back. As a result, the layers of the soil are preserved, during seeding and fertilizing. Thus, it is possible to plant seed or lay fertilizer without disturbing the stratification of the soil. It may be noted that the press wheels  18  may press the flaps back down, and assist in the maintenance of the stratification. 
   It is further understood that the invention is not limited to the exact shapes, sizes and orientations shown and described herein. For example, the blades may be shaped to have a rounded or blunted leading tip rather than the pointed tip shown in the figures. Similarly, the leading edge of the shank may be rounded, planar, or other geometrical shape. In addition, it is contemplated that one or more known or to be developed manufacturing techniques may be used to construct the soil preparation tool shown and described herein. For example, the blades could be welded to the shank or the blades and shank could be cast as a single unitary structure. It is also recognized that the individual components of the knife openers described herein may be coupled in a known manner whereby the individual components can be removed and/or replaced as desired. 
   Maintenance of soil stratification is important in currently-favored minimum-till farming regimes because moisture in the layers a few centimeters down is not dissipated, weed seeds on the surface remain on the surface and do not germinate, and stalks and vegetation at the surface remain intact providing cover and moisture retention. 
   Various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.

Technology Classification (CPC): 8