AU750343B2

AU750343B2 - In-line sub-surface seeding, fertilizing and watering device

Info

Publication number: AU750343B2
Application number: AU95255/98A
Authority: AU
Inventors: Noel D. Lempriere
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-10-16
Filing date: 1998-10-16
Publication date: 2002-07-18
Anticipated expiration: 2018-10-16
Also published as: EP1121011A1; CN1226910C; WO2000022913A1; BR9816051A; CN1314779A; EA200100450A1; AU9525598A; HK1040158B; EA002568B1; HK1040158A1

Description

WO 00/22913 PCT/CA98/00964 IN-LINE SUB-SURFACE SEEDING, FERTILIZING AND WATERING DEVICE Field of the Invention This invention relates to the field of no-tillage opening blades which may be partially submerged into earth, for example in a farmers field, so as to pass the blade at a submerged depth for delivery of seeds, fertilizer or water into the earth.

Backaround of the Invention This invention relates to blade delivery systems which have replaced tillage plows and the like. It is known that the use of plows or other devices having for example tillage discs for tilling the earth or otherwise opening and turning a furrow through the ground suffer from the disadvantage that the moisture in the soil is unnecessarily exposed to evaporation. In the past it was necessary to open the earth so that the ground beneath the surface could be seeded, fertilized and watered. Whether this was accomplished by machinery or done manually, prior art machines or manual systems also suffered from the disadvantage that fertilizer was typically delivered into close proximity to the seeds being sown occasionally resulting in the seeds becoming chemically burnt.

Thus there exists a need for, and it is an object of the present invention to provide, a blade which can be partially submerged into earth and translated therethrough, where the blade disturbs the earth minimally and without tillage and is adapted to deliver one or all of seeds, fertilizer or water from the blade in advantageous spaced apart relation as hereinafter described.

Summary of the Invention In summary, the sub-surface seeding, fertilizing and watering device of the present invention includes an opening blade having first and second sides extending between a WO 00/22913 PCT/CA98/00964 leading edge and an aft edge. The first and second sides are advantageously generally symmetrical to each other on either side of a first plane, where the first plane generally bisects the opening blade, and the leading edge and the aft edge lie generally in the first plane.

The opening blade has an upper surface and a lower surface extending between upper and lower edges respectively of the first and second sides of the blade. First and second wings are mounted to the first and second sides respectively in generally oppositely disposed relation so as to be cantilevered outwardly therefrom. The first and second wings extend between first and second forward wing edges and first and second aft-opening wing apertures in the first and second wings respectively. The first and second wings are mounted to the first and second sides at, respectively, first and second distances from the lower surface measured generally parallel to the first plane.

The opening blade has therethrough, and generally lying in the first plane, first and second conduits, extending from, and cooperating with, at uppermost ends thereof, first and second infeed ports in the upper surface. The first and second conduits cooperate with, at lowennrmost ends thereof, first and second wing ducts extending aft through the first and second wings respectively between the lowermost ends of the first and second conduits and the first and second aft opening wing apertures. The first and second conduits and the corresponding first and second wing ducts are thereby in material flow communication between the first and second infeed ports and the corresponding first and second aft opening wing apertures for seed, fertilizer or fluid flow, as fed from a material feeder, therethrough during the forward translation of the blade.

The opening blade is mountable to the material feeder so as to be generally vertically disposed, when mounted thereon, for partial submerging into soil to a first submerged depth advancing the leading edge through the soil. The first and second distances are less than the first submerged depth so that the first and second wings are submerged in the soil during the forward translation of the blade.

WO 00/22913 PCT/CA98/00964 In one preferred embodiment, the opening blade further includes a third conduit extending in material flow communication between a third infeed port in the upper surface and an aft opening blade aperture in a rearward position on the opening blade in proximity to the aft edge for seed, fertilizer or fluid flow therethrough, as fed from the material feeder.

Advantageously, the aft-opening blade aperture is centrally disposed relative to the first plane so as to lie generally symmetrically across the first plane, and may be positioned to aperture intersect the lower surface of the blade. Thus the aft-opening blade aperture is formed at the intersection of the lower surface and the aft edge of the blade. The aft-opening blade aperture may lie in a second plane at generally 30' inclined relative to a third plane generally containing the lower surface of the blade, wherein the third plane is generally orthogonal to the first plane.

Advantageously, the first, second and third conduits are generally parallel and raked aft of their corresponding first, second and third infeed ports. The first, second and third conduits may be raked aft at an angle of approximately 55' relative to a fourth plane generally containing the upper surface of the blade if the upper surface is a planar generally horizontal surface, although this is not necessarily so.

In one embodiment, but not so as to be limiting, at least the first and second conduits are formed by mating of corresponding opposed facing channels in oppositely mounted side panels, oppositely mounted in, or mountable into, first and second sides of the blade.

In a further aspect of the invention, the third conduit is generally parallel and adjacent the aft edge and the leading edge is concavely curved and forms a pointed toe at the intersection of the leading edge and the lower surface of the blade. Advantageously, the pointed toe may be made of hardened material relative to the hardness of material forming the balance of the opening blade.

WO 00/22913 PCT/CA98/00964 In a further aspect, the opening blade may be defined as having a longitudinal length dimension and a height dimension, where the longitudinal length dimension is perpendicular to the height dimension and both dimensions lie in the first plane. Further, the opening blade has a lateral width dimension perpendicular to the first plane.

The longitudinal length dimension extends between the leading and aft edges of the blade, the height dimension extends between the upper and lower surfaces of the blade, and the lateral width dimension extends between the first and second sides of the blade. In the present invention, the length dimension is much, that is, significantly greater than the width dimension, as described hereinafter. The height dimension in one embodiment is greater than the submerged depth so that the blade is supported above the soil and the blade thus partially submerged during forward translation, although this is not intended to be limiting. That is, it is readily conceivable to mount the blade to a support that itself becomes partially submerged in the soil.

Further advantageously, the first and second wings are wedge-shaped and the forward wing edges are vertices of the wedge-shaped wings.

The sides of the blade may be thought of as having upper and lower portions respectively above and below the wings. Thus, the first and second sides have upper portions generally located between the first and second wings and the upper surface of the blade, and lower portions generally located between the first and second wings and the lower surface of the blade. On one aspect of this invention, the lower portions collectively form a waisted shape so that a forward width dimension of a forward flared portion of the lower portion of the opening blade and an aft width dimension of an aft flared portion of the lower portion of the opening blade, the forward and aft width dimensions extending between the lower portions of the first and second sides, are greater than an intermediate width dimension of a waisted portion longitudinally extending contiguously between the forward and aft flared portions.

WO 00/22913 PCT/CA98/00964 The first wing may be defined as being set back a first longitudinal distance from the leading edge and the second wing as being set back a second longitudinal distance from the leading edge. Thus, in one aspect of this invention, the first longitudinal distance may be greater than the second longitudinal distance. Correspondingly, the first wing mounted to the first side of the blade at a first longitudinal location generally corresponding to the aft flared portion of the blade, and the second wing may be mounted to the second side at a second longitudinal location generally corresponding to the waisted portion of the blade.

In the wing design of the present invention, an upper wing surface on the first and second wings extends aft over the corresponding first and second aft-opening wing apertures on aft cantilevered upper wing members. The lower wing surface on the first and second wings may form a first wedge angle of approximately 50 with the upper wing surface.

Further, laterally outer-most wing surfaces extend between the upper and lower wing surfaces.

The outer-most wing surfaces may advantageously intersect the corresponding first and second sides of the blade at their corresponding first and second forward wing edges. Further, the outer-most wing surfaces may form a second wedge angle of approximately 50 relative to the first and second sides of the blade respectively. Advantageously, the first and second wings may themselves also be inclined downwardly so that a pair of corresponding planes bisecting the wedge angle between the upper and lower wing surfaces on each of the first and second wings, where the pair of corresponding planes contain the corresponding forward wing edges, are inclined forwardly and downwardly at approximately 5' relative to a generally horizontal plane containing the lower surface, it being taken for the sake of this defined relationship that the lower surface is generally planar and. horizontal, although this is not intended to be limiting, and is not necessarily so, notwithstanding that the preferred embodiment hereinafter described is illustrated as such.

WO 00/22913 PCT/CA98/00964 Brief Description of the Drawings Figure 1 is, in exploded perspective view, the inline, subsurface seeding, fertilizing and watering device of the present invention.

Figure 2 is a cross-sectional view along line 2-2 in Figure 1.

Figure 3 is, in left side elevation view, the device of Figure 1.

Figure 4 is, in bottom perspective view, the device of Figure 1.

Figure 5 is, in rear elevation view, the device of Figure 1.

Figure 6 is the view of Figure 5 as the blade is passed through soil.

Figure 7 is the rear elevation view of Figure 6 with the device of the present invention removed for clarity so as to illustrate an approximation of the soil mechanics during an initial seed placing and fertilizing phase.

Figure 8 follows on as a time-elapsed view of the view of Figure 7, illustrating the collapse of the soil and lateral translation of the seeds following the initial phase.

Detailed Description of the Preferred Embodiment As may be seen in Figure 1, the no-tillage in-line sub-surface seeding, fertilizing and watering device of the present invention is depicted in one preferred embodiment as opening blade 10. Opening blade 10 has an upper, ported, mounting block 12 rigidly mounted atop a generally planar blade structure 14. Blade structure 14 has a trunk 16 WO 00/22913 PCT/CA98/00964 depending generally vertically beneath the upper ported mounting block 12. Formed as part of the lower end of trunk 16 is a foot structure generally indicated by numeral 18.

As also seen in Figures 2-5, mounting block 12 and blade 14, including trunk 16 and foot 18, are elongate in a generally vertical plane including longitudinal axis A. With the exception of wings 20 and 22, as better described below, the outer surface of trunk 16 smoothly merges into, so as to truncate in cross-section as, a waisted or luge shaped foot lower surface 24. In one embodiment access panels 26 and 28, which conformally mount onto the lateral side walls of trunk 16, are symmetrically shaped relative to the plane of symmetry of trunk 16.

Upper ported mounting block 12 has ports 30, 32 and 34 formed in its upper surface. The ports extend downwardly through block 12 in coopeiative alignment with corresponding conduits or channels 36, 38 and 40 extending downwardly in generally parallel spaced apart array through trunk 16. Channel 40 also extends downwardly through foot 18.

Channels 36 and 38 may, in one preferred embodiment not intended to be limiting, be formed by the alignment and snug adjacency of flanges 42 and 44 on the inner sides of access panels 26 and 28 respectively when the access panels are mounted conformally in opposed relation, to the lateral sides of trunk 16 so as to cover cavity 46 in trunk 16. Access panels 26 and 28 may be mounted onto trunk 16 by means of tab 48 on access panel 26 slidably engaging corresponding slot 50 in trunk 16, formed in the lower surface defining cavity 46, so as to protrude downwardly into foot 18. In a similar fashion, tab 52 slidably engages slot 50 when mounting access panel 28 onto the starboard side of trunk 16. The upper ends of access panels 26 and 28 may be secured by releasable fasteners for example a cooperating, flush-mounted nut and bolt pair 56 or the like.

With access panels 26 and 28 mounted onto trunk 16, so as to cooperatively align flanges 42 and 44, thereby completing channels 36 and 38, channels 36 and 38 form a WO 00/22913 PCT/CA98/00964 pair of chutes in cooperative alignment between ports 30 and 32 in mounting block 12 and corresponding lower outlet ports 58 and 60. Lower outlet ports 58 and 60 are directed laterally oppositely and open into the respective interior ducts 62 and 64 formed within respective wings 20 and 22. Interior ducts 62 and 64 open out into corresponding aft-facing apertures from under their respective wings 20 and 22 as better hereinafter described.

Toe 66, which may be of a different and hardened material relative to the material forming mounting block 12, trunk 16 and foot 18, is rigidly mounted, by bolting or other means known in the art, to the forward portion of foot 18 so as to form a forwardly extending point or snout 68, forwardly facing in the direction of forward translation B when the blade is translated in use. Advantageously, mounting block 12, trunk 16 and foot 18 may be made of austempered ductile iron (ADI) and toe 66 may be made of a chrome alloy.

Access panels 26 and 28 and wings 20 and 22 may also be made of ADI.

Channel 40 is formed within and along the rear or aft edge of trunk 16 and foot 18 so as to form a continuous generally linear conduit between port 34 and rear aperture Advantageously, the rear-most end of foot lower surface 24 is upturned for example as to provide aperture 70 with an opening generally perpendicular to the longitudinal axis of channel 40. Further advantageously, channels 36, 38 and 40 are generally parallel so as to be raked aft in a downward direction from ports 30, 32 and 34..

Wings 20 and 22 are each shaped as truncated wedges or otherwise as what may be described as irregular pyramid shapes wherein the vertex of each wedge or pyramid is aligned so as to be forward facing (in direction B) with the wedge diverging aft so as to form correspondingly shaped interior ducts 62 and 64 opening aft through the base of the wedges.

In one preferred embodiment, the acute angles alpha (cx)and beta formed at the vertex of the wedges forming wings 20 and 22, are approximately 5 degrees. For sake of certainty, in the preferred embodiment upper surfaces 20a and 22a, lateral surfaces 20b and 22b, and lower surfaces 20c and 22c of wings 20 and 22 respectively are each generally planar. The upper WO 00/22913 PCT/CA98/00964 surfaces 20a and 22a are inclined forwardly slightly downwardly relative to the plane containing foot lower surface 24 advantageously at an angle of approximately Upper surfaces 20a and 22a extend aft and are cantilevered outwardly over the aft apertures of interior ducts 62 and 64. The aft apertures of interior ducts 62 and 64 are advantageously formed by reducing the longitudinal length of lateral side walls 20b and 22b and raking the rearmost edge of lower surfaces 20c and 22c so as to extend them contiguously aft from the rear edge of lateral side walls 20b and 22b respectively to blend with foot 18. In'the preferred embodiment, foot 18 is curvaceously waisted along its longitudinal length so as to form between curved side walls a forward expanded lateral dimension 72 smoothly tapering into a reduced lateral dimension 74 corresponding to the waisting and, progressing aft, a gentle flaring to an aft expanded lateral dimension 76. In the preferred embodiment the waist of foot 18 approximately corresponds in the longitudinal direction of axis A to the position of the forward ends of wings 20 and 22.

In use, blade 16 is translated in direction B through soil 78 as seen in Figure 6.

Blade 16 is driven forwardly and positioned so as to maintain wings 20 and 22 submerged at a shallow depth below the surface of soil 78. Such motion opens the soil from point 68 upwardly along the leading edge of foot 18 and blade 16 causing a small lifting and separating of soil 78 in opposite directions C. As blade 16 translates through the soil, material fed into ports 30, 32 and 34 flows under the force of gravity through respective channels 36, 38 and Material flowing through channel 40 exits through aperture 70 at the lowermost position of the narrow furrow 80 formed in soil 78 by the passing of blade 14 therethrough. The passing of wings 20 and 22 through soil 78 form shelves 82 in the soil as the soil is displaced by the wings so as to form shoulders 84 approximated in the illustration of Figure 7.

The forward movement of blade 14 through soil 78 draws material such as fertilizer 86 from aperture 70, and also draws material such as seeds 88 from ducts 62 and 64 as the seeds are fed from channels 36 and 38 through outlet ports 58 and 60 respectively.

WO 00/22913 PCT/CA98/00964 It has been found that the passing of wings 20 and 22 and the passing of foot 18 in their form as described herein, causes a fluid-like circulation in direction D of soil 78 aft of wings 20 and 22. It is understood that the view of Figure 7 is an approximation of the crosssection through the soil immediately behind blade 14 as it is translating through the soil. The soil, acting in a fluid manner, collapses so as to drop down shoulders 84 as the soil beneath shelves 82 is circulated in counter-rotation in direction D. Applicant has found that this circulation transports seeds 88 laterally outwardly along shelves 82 so as to facilitate advantageous lateral spacing apart of seeds on either side of furrow 80 separated both laterally and vertically from fertilizer 86 so as to inhibit chemical burning of the seeds for example by reason of the spacial relationship approximated by the illustration of Figure 8.

It is understood that the order and type of materials introduced into ports 30, 32 and 34 may be changed as would be known to one skilled in the art so as to introduce, for example, seeds through ports 30 and 32 and water through port 34. A person skilled in the art would also understand that ports 30, 32 and 34 would have to be attached by appropriate conduits to corresponding hoppers or reservoirs.

In the preferred embodiment, although not intended to be limiting, certain planes assist in defining the relationship of the elements of the present invention relative to one another as described above and claimed hereinbelow. Firstly, blade structure 14 is generally bisected by a first plane, referred to above as the plane of symmetry of trunk 16, which contains the cross-sectional view reference line 2-2 seen in Figure 1. The cross-sectional view of Figure 2 is a view through a cutaway along that first plane. A second plane E is the plane containing the edges of aperture 70 at the lowermost end of channel 40. A third plane F is the plane containing foot lower surface 24. A fourth plane G is the plane containing the upper surface of mounting block 12. Lastly, a wing bisecting plane H bisects wing 20 by bisecting angle beta and a corresponding parallel wing bisecting plane bisects wing 22 by bisecting the corresponding angle beta on wing 22.

WO 00/22913 PCT/CA98/00964 As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.

Claims

1. A sub-surface seeding, fertilizing and watering device comprising: an opening blade, said opening blade having first and second sides extending between a leading edge and an aft edge, said first and second sides generally symmetrical to each other on either side of a first plane, said first plane generally bisecting said opening blade, said leading edge and said aft edge lying generally in said first plane, said opening blade mountable to a material feeder so as to be generally vertically disposed when mounted thereon for partial submerging into soil to a first submerged depth during forward translation advancing said leading edge through the soil, said opening blade having an upper surface and a lower surface extending between upper and lower edges respectively of said first and second sides, first and second wings mounted to said first and second sides respectively in generally oppositely disposed relation so as to be cantilevered outwardly therefrom, said first and second wings extending between first and second forward wing edges and first and second aft-opening wing apertures in said first and second wings respectively, said first and second wings mounted to said first and second sides at, respectively, first and second distances from said lower surface measured generally parallel to said first plane, WO 00/22913 PCT/CA98/00964 said opening blade having therethrough, and generally lying in said first plane, first and second conduits, said first and second conduits extending from, and cooperating with, at uppermost ends thereof, first and second infeed ports in said upper surface, said first and second conduits cooperating with, at lowermost ends thereof, first and second wing ducts extending aft through said first and second wings respectively between said lowermost ends of said first and second conduits and said first and second aft opening wing apertures, said first and second conduits and corresponding said first and second wing ducts thereby in material flow communication between said first and second infeed ports and corresponding said first and second aft opening wing apertures for seed, fertilizer or fluid flow, as fed from said material feeder, therethrough during said forward translation, wherein said first and second distances are less than said first submerged depth so that said first and second wings are submerged in the soil during said forward translation.

2. The device of claim 1 wherein said opening blade further comprises a third conduit extending in material flow communication between a third infeed port in said upper surface and an aft opening blade aperture in a rearward position on said opening blade in proximity to said aft edge for seed, fertilizer or fluid flow, as fed from said material feeder, therethrough during said forward translation.

3. The device of claim 2 wherein said aft-opening blade aperture is centrally disposed relative to said first plane so as to lie generally symmetrically across said first plane. WO 00/22913 PCT/CA98/00964

4. The device of claim 3 wherein said aft-opening blade aperture intersects said lower surface.

The device of claim 4 wherein said aft-opening blade aperture is formed at the intersection of said lower surface and said aft edge.

6. The device of claim 5 wherein said aft-opening blade aperture lies in a second plane at generally 300 inclined relative to a third plane generally containing said lower surface, wherein said third plane is generally orthogonal to said first plane.

7. The device of claim 2 wherein said first, second and third conduits are generally parallel and raked aft of corresponding said first, second and third infeed ports.

8. The device of claim 7 wherein said first, second and third conduits are raked aft at an angle of approximately 550 relative to a fourth plane generally containing said upper surface.

9. The device of claim 7 wherein at least said first and second conduits are formed by mating of corresponding opposed facing channels in oppositely mounted side panels, oppositely mounted in said first and second sides.

The device of claim 9 wherein said third conduit is generally parallel and adjacent said aft edge.

11. The device of claim 1 wherein said leading edge is concavely curved and forms a pointed toe at an intersection of said leading edge and said lower surface.

12. The device of claim 11 wherein said pointed toe is made of hardened material relative to the hardness of material forming the balance of said opening blade. WO 00/22913 PCT/CA98/00964

13. The device of claim 11 wherein said opening blade has a longitudinal length dimension and a height dimension, said longitudinal length dimension perpendicular to said height dimension and both lying in said first plane, and wherein said opening blade has a lateral width dimension perpendicular to said first plane, said longitudinal length dimension extending between said leading and aft edges, said height dimension extending between said upper and lower surfaces, and said lateral width dimension extending between said first and second sides, wherein said length dimension is much greater than said width dimension, and wherein said height dimension is greater than said submerged depth, and wherein said first and second wings are wedge-shaped and said forward wing edges are vertices of said wedge-shaped wings.

14. The device of claim 13 wherein said first and second sides have upper portions generally located between said first and second wings and said upper surface, and lower portions generally located between said first and second wings and said lower surface, and wherein said lower portions collectively form a waisted shape so that a forward width dimension of a forward flared portion of said opening blade and an aft width dimension of an aft flared portion of said opening blade, said forward and aft width dimensions extending between said lower portions of said first and second sides, are greater than an intermediate width dimension of a waisted portion longitudinally extending contiguously between said forward and aft flared portions.

WO 00/22913 PCT/CA98/00964 The device of claim 14 wherein said first wing is set back a first longitudinal distance from said leading edge and said second wing is set back a second longitudinal distance from said leading edge, and wherein said first longitudinal distance is greater than said second longitudinal distance, said first wing mounted to said first side at a first longitudinal location generally corresponding to said aft flared portion and said second wing mounted to said second side at a second longitudinal location generally corresponding to said waisted portion.

16. The device of claim 14 wherein an upper wing surface on said first and second wings extends aft over corresponding said first and second aft-opening wing apertures on aft cantilevered upper wing members.

17. The device of claim 16 wherein a lower wing surface on said first and second wings forms a first wedge angle of approximately 50 with said upper wing surface.

18. The device of claim 17 wherein laterally outer-most wing surfaces extend between said upper and lower wing surfaces on said first and second wings, and wherein said outer- most wing surfaces intersect corresponding said first and second sides at corresponding said first and second forward wing edges.

19. The device of claim 18 wherein said outer-most wing surfaces form a second wedge angle of approximately 5' with said first and second sides respectively. The device of claim 16 wherein said first and second wings are inclined downwardly so that a pair of corresponding planes bisecting a wedge angle between upper and lower wing surfaces on each of said first and second wings, said pair of corresponding planes containing corresponding said forward wing edges, are inclined forwardly and downwardly at approximately 50 relative to a generally horizontal plane containing said lower surface.

WO 00/22913 PCT/CA98/00964

21. The device of claim 1 wherein said first and second wings are wedge-shaped and said forward wing edges are vertices of said wedge-shaped wings, wherein said first and second sides have upper portions generally located between said first and second wings and said upper surface, and lower portions generally located between said first and second wings and said lower surface, and wherein said lower portions collectively form a waisted shape so that a forward width dimension of a .forward flared portion of said opening blade and an aft width dimension of an aft flared portion of said opening blade, said forward and aft width dimensions extending between said lower portions of said first and second sides, are greater than an intermediate width dimension of a waisted portion longitudinally extending contiguously between said forward and aft flared portions.

22. The device of claim 21 wherein said first wing is set back a first longitudinal distance from said leading edge and said second wing is set back a second longitudinal distance from said leading edge, and wherein said first longitudinal distance is greater than said second longitudinal distance, said first wing mounted to said first side at a first longitudinal location generally corresponding to said aft flared portion and said second wing mounted to said second side at a second longitudinal location generally corresponding to said waisted portion.

23. The device of claim 21 wherein an upper wing surface on said first and second wings extends aft over corresponding said first and second aft-opening wing apertures on aft cantilevered upper wing members.

24. The device of claim 23 wherein a lower wing surface on said first and second wings forms a first wedge angle of approximately 5' with said upper wing surface.

WO 00/22913 PCT/CA98/00964 The device of claim 24 wherein laterally outer-most wing surfaces extend between said upper and lower wing surfaces on said first and second wings, and wherein said outer- most wing surfaces intersect corresponding said first and second sides at corresponding said first and second forward wing edges.

26. The device of claim 25 wherein said outer-most wing surfaces form a second wedge angle of approximately 50 with said first and second sides respectively.

27. The device of claim 23 wherein said first and second wings are inclined downwardly so that a pair of corresponding planes bisecting a wedge angle between upper and lower wing surfaces on each of said first and second wings, said pair of corresponding planes containing corresponding said forward wing edges, are inclined forwardly and downwardly at approximately 50 relative to a generally horizontal plane containing said lower surface.