Abstract:
A ground-engaging paired row furrow forming tool includes a tool body having fore and aft ends with an outer edge defined on each of two opposing sides of the tool body. A furrowing wing is located adjacent each of the opposing sides and protrudes from bottom portions of the tool body. The tool body has lower surfaces including a central front surface portion which is angled upwards towards the fore end and a center passage is defined between the furrowing wings. This passageway is in part defined by a central rear surface portion which is adapted to be substantially aligned fore to aft in a direction of travel T during operation of the ground engaging tool. This paired row opener works well without compromise in a broad range of soil conditions without fouling and enables planting of seed rows spaced widely apart while minimizing soil surface disturbance.

Description:
This is a divisional of co-depending application Ser. No. 09/538,170 filed on Mar. 30, 2000. 
    
    
     FIELD OF THE ART 
     This invention relates to an agricultural furrow opening tool for planting seeds in paired rows. 
     DESCRIPTION OF PRIOR ART 
     It is commonly desirable to perform seeding and fertilizing operations in one pass over a field to be planted. This trend has continued with advancements in low-till and no-till planting implements. Ground working tools have evolved for planting in these no-till and low-till conditions and for improving seed bed utilization. Presently a wide variety of types of ground working tools are available for planting in various soil conditions. These ground working tools are generally categorized as disc types or hoe types. Existing ground working tools designed for working well in certain conditions are not always suitable in other conditions. 
     For many types of crops such as cereals and oilseeds, planting of the seeds is efficiently achieved by bulk metering. The seeds become generally evenly spaced as seeds are distributed at a seeding rate through distribution lines to ground working tools by which they are planted in rows in the soil. The rows are spaced to achieve the best possible utilization of the soil area, however other factors effect row spacing, such as the need to allow field trash to pass between ground working tools while they are pulled through the soil for planting. This has led to the development of paired row seeding tools which each plant two rows of seed to achieve good seedbed utilization with fewer tools thus also allowing good field trash flow. It is also common that these tools are also designed to simultaneously place a fertilizer row between the seed rows. Research has shown that precise placement of seed at particular spacing along side an appropriate amount and type of fertilizer improves yields. 
     One such ground working tool is provided according to U.S. Pat. No. 5,025,736 by Anderson. A hoe ground working tool is disclosed which has a narrow leading end for opening a furrow for placement of fertilizer. Trailing the leading end is a press plate which tapers to a wider rearward end from a forward end centered behind the leading end. The press plate is also angled downwards and rearwards from the leading end. It acts to press down on an area wider than the furrow opened for fertilizer for closing the fertilizer furrow and preparing a firm seedbed. It has a wear strip along each side of the press plate which is claimed to extend beyond the rear end of the press plate so that grooves are formed in the seed bed. A seed distribution tube carries seed to a divider disposed behind the press plate which randomly divides the seed into two streams directing the seed to the sides of the seed bed and into the laterally spaced grooves. However it is known that in some soil conditions, particularly that known as heavy soil, more aggressive action is required to close the fertilizer furrow. If this furrow remains unclosed and no level seedbed is formed, then a large amount of seed falls into the fertilizer furrow rather than being placed to each side. Fertilizer too close to the seed is toxic to the seed as it germinates and they will die. 
     A similar hoe ground opener is disclosed in U.S. Pat. No. 4,674,419 by Kopecky. An auxiliary press plate is disclosed which has somewhat more aggressive wings for forming seed furrows. The press plate has a main flat central surface which in operation is also angled downwards and rearwards from a leading end to press down over a fertilizer furrow created by a preceding narrow opener. The wings have inner surfaces that taper laterally and downwardly from the central surface and outer surfaces that are generally vertical. The wings inner surfaces also converge toward the rear of the plate and thus in operation push some soil inwardly to close the fertilizer furrow. Such an arrangement of surfaces is more aggressive at closing a fertilizer furrow. However in conditions of heavy soil, when the soil is wet it tends to be bulldozed by opener surfaces that are too aggressive or restrict passage of the soil. The soil can bind to a furrow opener&#39;s surfaces. In these conditions ground tools do not properly cover the fertilizer furrow and seed and fertilizer are scattered ineffectively. A planting tools fertilizer delivery openings can even become blocked by soil that is pushed and builds up in front of the seed furrow forming surfaces. In fact, the Anderson patent discloses using low friction plastic as a press plate to prevent binding of soil. This can lead to a costly construction. 
     Flexicoil Ltd. also discloses furrow openers as shown on pages 45-47 of their Product Book (volume 2). Two different openers are promoted for use in different soil conditions. For heavy soil an HS paired row opener is promoted having a main central surface that runs level in operation, and wings that form a seed furrow on each side of a fertilizer furrow. Since the main surface runs level, it does not tend to restrict passage of heavy wet soils. It produces paired seed rows that are spaced apart about 2.5 inches. However if such an opener is made with wings more widely spaced for wider space between seed rows, it has been found that this shape may not perform aggressively enough to properly close the fertilizer furrow in all conditions. An LS paired row opener is promoted for use in light soils. It does not include a central pressing surface and rather the wing surfaces converge at a central edge forming bottom surfaces in an inverted V arrangement. The central edge runs generally horizontal. The wings also have leading surfaces that face slightly inward and downward for gathering soil and directing it inwards and downwards as it passes beneath the opener, closing the fertilizer furrow. This shape however has found to be too aggressive for heavy soils which becomes stuck between the wings. 
     In heavy wet soils particularly, the soil tends to bind to seeding tool surfaces between paired furrowing wings when those surfaces intersect at small obtuse angles or have little or no radius between them so the intersection forms a more distinct edge. Soil binding is more problematic especially when the intersection of the soil deflecting surfaces is angled or transverse to the direction of travel, and even when the angle between surfaces is moderately obtuse. Even with a surface smoothly curved, if there is significant concave curvature in a plane in the direction of travel, the soil tends to bind in the concavity. 
     It is desirable to have a paired row opener that works well without compromise in a broader range of soil conditions without fouling, and one which plants seed rows spaced widely while minimizing soil surface disturbance. 
     It is desirable to have these paired rows spaced sufficiently wide, closer to rows of adjacent tools, so there are not large spaces between rows planted by adjacent tools. Thus, during harvest there is an even stand of stubble to support a swath of cut crop above the ground for proper drying. 
     The prior art openers are generally quite narrow for seeding pairs of seed rows that are spaced quite closely. Seedbed forming portions of these planting tools generally operate within a space following a fertilizer furrow opening portion in which field trash has been cleared by the fertilizer opening portion. The seedbed forming portions therefor generally operate in soil that is substantially clear of field trash. An additional challenge in designing seedbed forming sections that form wider spaced paired rows is that a wider paired row opener will encounter field trash at it&#39;s outer edges which must not become caught on the opener, fouling it&#39;s operation. 
     SUMMARY OF THE INVENTION 
     A basic object of the invention is to provide an improved paired row opener that works well without compromise in a broader range of soil conditions without fouling, and one which plants seed rows spaced widely while minimizing soil surface disturbance. 
     Thus, in one aspect, the invention provides a ground engaging paired row furrow forming tool comprising: a tool body having fore and aft ends, an outer edge on each of two opposing sides of the tool body; a furrowing wing adjacent each of the opposing sides and protruding from bottom portions of the tool body; the tool body having lower surfaces including a central front surface portion which is angled upwards towards the fore end and a center passage being defined between the wings and which passageway is in part defined by a central rear surface portion which is substantially aligned fore to aft in a direction of travel T during operation of the ground engaging tool. 
     In a further aspect the invention provides a ground engaging paired row furrow forming tool comprising: a tool body having fore and aft ends, said body having surface portions defining an outer perimeter extending on each of two opposing sides of the tool body; a furrow forming wing adjacent each of the opposing sides and protruding in spaced apart relation from bottom portions of the tool body; said tool body having lower surfaces including a central front surface portion which is angled upwards towards the fore end and which leads into a central passage extending rearwardly of the tool body between the wings, which passage is capable of being substantially aligned fore to aft in a direction of travel during operation of the furrow forming tool. 
     Other features and advantages of the invention will become apparent from the following description of a preferred embodiment and the appended claims. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 is a side view of a hoe planting tool used for one pass fertilizing and paired row seeding. 
     FIG. 1A is a perspective view of the planting tool in FIG.  1 . 
     FIG. 2 is a side view of a paired row furrowing and seeding tool. 
     FIG. 3 is a bottom view of the seeding tool in FIG.  2 . 
     FIG. 4 is a view of a cross section taken through a line of symmetry of the seeding tool in FIG.  5 . 
     FIG. 5 is a rear view of the seeding tool in FIG.  2 . 
     FIG. 6 is a top perspective view of the seeding tool in FIG.  2 . 
     FIG. 7 is a bottom perspective view of the seeding tool in FIG.  2 . 
     FIG. 8 shows agricultural implement on which a seeding tool as shown in FIG. 2 is typically used. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     A hoe planting tool  1  has a mounting portion  14  for securing to a shank  2 . A plurality of planting tools  1  and shanks  2  are typically attached to a tillage implement  7  to fore and aft spaced toolbars as can be seen in FIG. 8 with a plurality of them spaced transversely on each toolbar. The spaced arrangement is selected to allow the best passage of field trash between adjacent tools yet minimize soil ridging. Three to five toolbars are typically provided, depending on the spacing desired between planted rows. The implement  7  includes a hitch  9  for attachment to a vehicle such as a tractor for pulling the implement across a field. A product cart  8  can be towed behind the tillage implement  7 , or alternately between the tractor and implement  7 . The product cart delivers seed and fertilizer through distribution headers  5 , 6  and distribution lines  3 , 4  to the planting tools  1  for planting in the soil. 
     As seen in FIG. 1 the planting tool  1  comprises a narrow soil opener  10  and a paired row opener  20 . Possibly these could be made as an integral opener, but narrow opener  10  is useful alone or in combination with other openers. The hoe planting tool  1  is a combination tool for one pass fertilizing and paired row seeding. It operates in the soil at a set depth controlled by the tillage implement  7 . In such operation the soil opener  10  places fertilizer while the paired row opener  20  places seed. The opener  10  includes a furrowing tip  13  secured to the frontal lower body portion  15  of the opener  10 . The upper body portion  14  of opener  10  is adapted for securing to a previously noted shank  2 , in a well known manner. The opener  10  receives fertilizer at inlet  11  and directs it from a lower outlet  12  into a fertilizer furrow formed by furrowing tip  13 . 
     The paired row seeding tool  20  includes two furrowing wings  30  as best seen in FIGS. 4 and 5, protrude below the main body of seeding tool  20 . Seeding tool  20  receives seed at an inlet  21  and directs it from outlets  22  into paired furrows formed by lower surfaces of wings  30 . A passage from inlet  21  within seeding tool  20  divides into two passages having outlets  22  and randomly and evenly separates seed into a pair of streams to be placed in the paired furrows. The seeding tool  20  is fastened to the rear of the opener  10  by fasteners  19  in well-known manner. 
     The body of the seeding tool  20  generally includes lower surfaces and upper surfaces, certain of which converge together to form outer edges  35  extending along the left and right sides of the seeding tool. These outer edges  35  are curved inwardly and upwardly toward the front of the seeding tool  20 . This curvature provides for shedding of field trash which might otherwise become caught on the seeding tool, in which event its operation is fouled and proper furrows are not formed. Left and right tool body upper surfaces  34  are angled upwards and inwards from outer edges  35  to the narrower central body of the seeding tool  20  and extend generally straight fore and aft in the direction of operation. Rearward portions of the outer edges  35  are straight and the seeding tool  20  is operated with these straight portions generally horizontal and at a depth in the soil at which the soil surface is at or above the edges  35  and along the upper surfaces  34 . The upper surfaces  34  in operation slip below the soil surface with minimum disturbance of the soil surface. 
     Seeding tool  20  is also suitable in sizes that have a width exceeding the trash cleared zone created by the soil opener  10 . The outwardly curved outer edges  35  prevent trash being pulled into and under the furrowing wings  30 , and prevent trash from remaining caught on the edges  35 . Moving along edges  35  from front to rear it will be seen that they gradually curve into general alignment with the direction of travel, so the parts of the outer edges  35  that are subject to field trash are generally aligned with the direction of travel and tend to shed off the trash. 
     The bottom side of seeding tool  20  comprises a central surface, the profile of which can be seen in the cross section of FIG.  4 . The central surface includes a central front portion  24  and a central rear surface portion  23  (FIG. 3) extending rearwardly therefrom in alignment with the direction of travel T. (FIGS.  3  and  7 ). Rear surface portion  23  is preferably at least about ¾ inch wide. The central rear surface  23  preferably is generally flat and level when in operation and the central front surface  24  is preferably angled slightly upwards and forwards relative to central rear surface  23 . These surface portions  23 ,  24  are preferably blended together by a smoothly curved transition region  25  (FIG. 4) between them rather than having a distinct edge at which they intersect. This curvature is generally convex fore to aft and helps prevent soil from binding. The central front surface  24  presses soil downwards at a decreasing rate as it passes beneath the surface so that soil is not simultaneously subject to pressure from the wings  30  in a combination of forces that may otherwise cause relative movement of the soil to stall. The tool is normally oriented in operation so the central front surface  24  is angled upwards from the horizontal. There is preferably about ⅜ inch rise in the central front surface  24  from the rear to the front edge. 
     A furrow forming wing  30  as previously noted is positioned to each side of the central surfaces  23 ,  24  as seen in FIG.  3  and FIG.  5 . Each wing  30  includes a forward lower surface  31 , an inner surface  32 , and an outer surface  33 . The dihedral angle between inner surfaces  32  of wings  30  is shown as being approximately 90° although this angle can be varied somewhat. The wing forward surfaces  31  are arranged in flanking relation to the central front surface  24  and each surface  31  extends laterally, rearwards and downwards from the central front surface  24 . The forward surfaces  31  are therefore inclined such as to slightly face each other, and they taper inwards and rearwards so in operation they direct some soil inwards and downwards over the fertilizer furrow formed by the soil opener  10 . The wing inner surfaces  32  extend outwards and downwards from the central rear surface  23 , and intersect with the forward surface  31 . The wing outer surfaces  33  extend inwards and downwards from outer edges  35  to intersect with surfaces  31  and  32  and defining furrows forming edges  36  which are angled inwardly from fore to aft before reaching the extension edges  36 , which are parallel to each other and to the travel direction T. In FIG. 5 rear view it can be seen that wing inner surfaces  32  and outer surfaces  33  converge to form V-shape profiles which operate to form corresponding V-shaped furrows. The tips of the V-shapes (which are defined by the extension edges  36 ) are preferably spaced apart, at least about 3 inches. The wing inner and outer surfaces  32 ,  33  extend generally parallel to the direction of travel T thus giving the wings  30  a longer wear life in which they maintain their furrow forming profile. A forward part of each wing outer surface  33  is curved to follow the associated curved outer edge  35 . Preferably the forward surface  31  is curved toward the rear to blend with inner surface  32  so there is no distinct edge along the intersection of these surfaces. The central front and rear surfaces  23 ,  24  also blend along curved intersections with wing forward surfaces  31  and wing inner surfaces  32  so there are no distinct edges of intersection. This promotes smooth soil flow and prevents soil binding which often is evident where surface intersect at edges, particularly at sharper angles. 
     The edges  36  of the forward surfaces  31  appear as substantially straight in a side profile as can be seen in FIG.  2  and FIG.  4 . This is generally the same across the forward surfaces  31  and through the intersections with the central front surface  24  so that there is little to no concave curvature or angles in a plane in the direction of travel, in which soil can hang up and bind. Central rear surface  23  provides a free central passage between wings  30  where the soil is not simultaneously subject to downward deflection as the V-shaped furrows are being formed. Preferably the central rear surface  23  provides a space of about ¾ inch minimum between the bases of the wings  30  to provide a free passage for soil flow. (This is in contrast to certain prior art designs in which a surface between furrow forming wings continues to deflect soil downwards during furrow formation.) A small fillet or radius is formed between the wing surfaces  32  and central rear surface  23  to provide free passage of soil. 
     Seed passage outlets  22 , best seen in FIG. 5, are positioned behind each wing  30  with the outlets terminating above the lowermost edge  36  of each wing, preferably a distance of ¾ inch, which provides good control of material placement and prevents soil from blocking the outlets. 
     In operation, the seeding tool  20  is generally oriented with central rear surface  23  substantially horizontal (see FIG.  4 ). It may be slightly trimmed from this orientation with central rear surface  23  angled one or two degrees upward or downward from front to rear, depending on soil conditions. This can be achieved by adjusting a stop on a tripping device supporting the shank  2 , or by using shims in mounting the ground engaging tool  1  to change its angle relative to the shank  2 . 
     Although the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes may be made without departing from the spirit and scope of the invention.