AU7156400A - Point nose cone - Google Patents

Description

P( LC~ A -icr0o(0 no 0 71,56 41 0 TITLE LAMINATED DIGGING TOOL

DESCRIEPTION

This invention relates to improvements in devices for digging soil.

Pasture and cropping soils in Australia are declining in productivity. Increasingly these soils have "collapsed", they have lost their "structure" or their ability to form "crumbs" and are being compacted.

Overstocking, heavy machinery and the soil inverting, mould-board plough type implements and the use of farm chemicals all combine to contribute to this problem.

Conventional farming techniques have deprived the top layer of soil of enough organic matter for the individual particles of sand, silt and clay to adhere together to form crumbs which are the basis of adequate soil structure. The "collapsed" soil particles are compacted by stock, machines and mould-board type implements eg. disc plough, scarifiers. The latter place a seal or smear or shear line under the inverted soil. The seal was part of the design of the mould-board plough which was developed in Northern Europe where the seal provided a drain for the high rainfall over the undulating landscape serviced by river systems that flowed quickly to the sea.

Mould board plough implements have been less successful in Australia due to our harsh climate, the flat landscape and rivers that for long periods do not flow.

Over time the seal forms a compacted layer 50 to 75 mm below the surface. Air, water, sunlight and plant roots cannot enter this compacted layer or hardpan. Plant roots are unable to obtain enough nutrients, minerals, air, water and energy for growth. Runoff washes soluble soil salts, from the collapsed soil in the top layer, over the hardpan to the low points. The water ponds, evaporates and leaves salty, unproductive soil.

Conventional farming response to this problem has been inadequate. Farmers are encouraged to plough less often ("minimum tillage") or not at all ("no till"). Fertilizers are increasingly used to supply nutrients and minerals. Fertilizer chemicals add to the problem. Fertilizers are salts and add to salt load in the soil. Superphosphate, used to supply phosphorus, is acidic. The acids, dilute sulphuric and hydrofluoric acid, attack the organic matter in the soil. Sulphuric acid comes from the manufacture of super phosphate and fluoride is an impurity which reacts with water to form the short lived hydrofluoric acid. Soil conditioners such as lime (a base) are added to neutralize the acid. Salt plus water results. These are flushed to the low points. Super mobilizes salts in the soil as it is 47% gypsum (CaSo 4 and the calcium mobilizes sodium (by ion exchange) which is washed to the low points. Similarly with nitrate fertilizers which mobilize chloride from the soil. Pesticides which are salts or degrade to salts are used to control weeds instead of ploughing..

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B1~ateh~~ f Conventional farming has not addressed the main issue of soil collapse and compaction. However the problem has been known about since early last century.

Subsoilers that broke the soil to 400 450 mm but did not turn it over have been used with success since that time. An example is the Rackheath Plough built mostly from timber in the 1830's (Refer to drawing 1) From A to B 6 feet.

Drawing I During the 1960's in Australia a new plough was developed. The "aeration" plough grew from the "chisel" plough. The latter is a spring steel tined implement, semi circular in shape built from rectangular section steel with a leading edge point.

0 *.0 0 .00:e 00.0• The tines are attached to the frame and are pulled through the soil at a depth greater than the Drawing 2 PERSPECTIVE hardpan. The chisel plough was ineffective due to the high resistance loads as the chisel plough tine presented its largest cross sectional dimension to the soil. Vibration of the tine tended to further compact the soil.

Drawing 3 VIEW OF AERATION PLOUGH The aeration plough was based on ancient wooden ploughs that consisted of a raking "leg" or "shank" with a detachable "shoe" or "point' The "aeration' plough presented its smallest shank dimension to the soil face and provided much less resistance than the chisel plough. The shank is rigidly supported to a frame by a point with a sacrificial shear pin (or "stump jump" mechanism) to account for immovable objects.

The "aeration" plough applies three load systems to the soil simultaneously at a depth just below the hardpan (150- 250mm). The first load system is imposed by two or more points side by side and acts on the soil ahead of the point as shown in the plan.

V.e.acItov fOres 4f soiI 4 4 4 L II Drawing 4 PLAN cleapeva#~ O sonil 4-lee, The "beam" of compacted soil is shattered by shear and tensile forces between the points.

Spacing of the points depends on the soil type, compaction and moisture content.

The second load system is imposed by the point lifting the soil as shown in the side elevation drawing.

ViecA-iot^ r I 'Shai-erec Si I Drawing 5 SIDE ELEVATION The third load system is imposed by the top of the point and cutting action of the shank as shown in the front elevation.

S'ekrea -Sd I P~;Y\t lUaraA"\ Drawing 6 FRONT ELEVATION (only single point shown) The simultaneous application of the load systems creates numerous forces on the soil that breaks the soil apart. The size of the resulting particles decides the success of the ploughing process.

The smaller the particle size the better. The larger the particles the greater the number of extra passes needed to further break these down. The smaller the particle the quicker air, water, sunlight and plant roots act to form soil structure.

The inventor has extensively researched "aeration" ploughs and found that there are some problems with their use. In attempting to overcome these problems the inventor developed the laminated digging tool.

The main problem of all existing points is that they wear very quickly. From the drawings it is obvious that the maximum load is at the tip. The inventor has found that the sharpness of the tip is the most important factor in the efficiency of the shattering process. The tip has to be sharp and retain its sharpness. All points available commercially wear very quickly as they are too soft.

The tip becomes rounded especially in plan so that shattering of the soil is ineffective. The resulting particles are too big. Points need to be replaced twice a day which is costly and time consuming (typically a point costs $40 and an average plough would have 15 shanks replacement costs of $1 200 per day). To reduce wear, ploughing is often carried out in soil that is too wet. Shattering does not occur and more compaction can occur due to the water acting as a lubricant. Large clods in excess of 300mm diameter can also be formed if the soil is not dry enough. If the soil is too dry the rate of wear, fuel and maintenance costs rapidly increase using commercially available points.

The laminated digging tool has been designed to operate under the driest conditions i.e. for maximum shattering effect resulting in the smallest particles. Dry conditions require maximum strength and maximum resistance to wear.

The inventor has found that for a point to retain its sharpness it has to: have high strength at high temperatures have high surface resistance to wear, not chip or crack retain its shape with uniform resistance to wear be ductile rather than brittle dissipate heat The invention applies to all forms, shapes and configurations of the tip. However for agricultural applications these factors are constrained by the need for the tip to: concentrate the applied loads and so apply maximum breaking and lifting forces on the soil at ()minimize resistance or drag forces by being compact and have a low surface area.

not impose a seal or smear under it that could lead to hardpans forming at greater depth.

The inventor found the truncated triangular pyramid shape to be the most efficient for agricultural use. Refer to drawing.

SIlDE A IZc,4T f'pOIf E1LEVATIOP -L4kTO PERPE CT 14 Drawing 7 I 4 Solid tips of steel and tungsten were trailed but were found to be too brittle the tip rapidly chipped or broke off.

Horizontal layers of tungsten were then trailed with the laminations connected with silver solder.

The connections failed. However when nickel bronze was used the tip proved to be effective.

Any connections can be used in the laminated digging tool including welds, solder, bronze, glue, fusing, rivets, bolts, shear connections or interlocking shapes or any combination of these. An example of the laminated digging tool is shown below.

Anle of nxvoe SI4Q- FLEVATto &I cTi 0 0to* 9* a PLAN F Drawing 8 ~EVb~T~o 14 The laminated digging tool laminations can be of any material including metal(s), ceramic(s), alloy(s), fibre(s), compound(s) or combination of any of the above.

For the trial models recycled tool tungsten was used. The laminations were approx. 5mm thick and were isosceles triangle shape with a base width of 15mm and a height of cutting tip to base of approx. A further improvement has been a larger, slightly protruding bottom lamination and the top slightly smaller recessed laminations as shown.

SItDE. ELEJVATIoW4 ?a 1Z 5I F 1% F PLA M Drawing 9 VIOIT FLEVATIog4 The protruding bottom lamination initiates the cutting and lifting process and is subjected to the maximum amount of wear and is the first to need replacing. On heavily compacted, dry soil annual replacement may be necessary versus two to three years for the other laminations.

The top recessed lamination "streamlines" the digging process as the particles that are lifting from the bottom are allowed room to move. The recessing minimizes wear.

The most efficient angle of rake of the leading edge of the laminated digging tool was found to be 200 when used as a tip for a "Wallace" point. However the invention is not constrained to this angle of rake as the invention applies to all angles of rake.

The thickness of laminations used in the trial models of the laminated digging tool varied from 6mm to 4mm. However the invention is not constrained to these thicknesses. The laminations can be of any thickness and there can be any number of laminations to construct a laminated digging tool.

The preferred option of the invention for agricultural use is to combine it with a reinforced "Wallace" plough point. The invention is applicable as a tip or point for all other agricultural digging, ploughing, tilling and scarifying tools that require sharp points.

The "Wallace" plough point is constructed from three pieces of steel plate and has not been patented. The inventor, besides combining the "Wallace" point with his laminated digging tool has made improvements to this point which are part of this application. The "Wallace" point is a triangular pyramid shape as shown in the drawing.

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SEiof -LEVAT0o-4 Drawing ~AF LF-VATIC>4 The inventor chose the "Wallace" point as it has proven to be the most efficient at breaking and lifting soil. The inventor has reinforced the "Wallace" point along all its edges with tungsten cutting tool blocks, magnesium bronzed to the point, with a tungsten laminated digging tool at the tip as shown in the drawing.

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-SrIDE -LEVAC1orlO Drawing 11 The reinforcing laminations applied to the "Wallace" point along its edges and the intermediate laminations along each face not only protect the steel from wear but also lower resistance forces or drag so the point requires less effort to be pulled through the soil. The reinforcing laminations also act as containing boxes for soil so that a "boundary layer" of soil assists in the reinforcing process as shown in the drawing. The spacing of the intermediate reinforcing laminations is decided by the containing box's ability to contain soil i.e.

how well the soil adheres to the point surface.

*CGorha'Yed so~1 Sod Drawing 12 SECTION THROUGH POINT The reinforcing laminations can be of any material, shape, size, configuration and can be connected by any method. The reinforcing laminations are applicable to all agricultural digging, ploughing, tilling or scarifying tools.

The laminated digging tool has applications in agriculture, mining, excavation and construction.

The laminated digging tool can be a tip combined with some other digging point or can stand alone.

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COMBINATION

Drawing 13 STAND ALONE The stand alone option can be solid, hollow or the laminations can be connected to an inner core using continuous or built up laminations.

The laminated digging point can be of any shape including conical, pyramid or wedge.

4 Drawing 14

Claims (6)

1. A laminated digging tool device comprising of two or more laminations connected together, with the laminations approximately parallel to the digging forces, that concentrates the applied digging forces to the extent that the material being dug is forced out of the path of the moving digging tool, the laminations giving an increase in strength, ductility, toughness, wear and heat dissipation compared to a digging tool of the same shape built from the lamination material alone.

2. The laminated digging tool of claim 1 can be of any shape, form or configuration, the laminations can be of any material and the connections can be of any type and there can be any number of laminations.

3. The preferred option of the laminated digging tool of claim 1 for agricultural use is that detailed in drawing N 0

9. 4. The preferred option of the laminated digging tool of claim 1 for agriculture is further ~*:preferred to be combined with a reinforced "Wallace" point as detailed in drawing N 0

11. 5. The preferred combination laminated digging tool of claim 4 breaks the seal, shear line or hardpan of compacted soils, preventing salt build up in the low points and rejuvenates soil that is already salted. 6. The preferred combination laminated digging tool of claim 4 shatters soils into particles so that air, water and sunlight (energy) can enter and leave the soil as part of natural cycles and allows mineralization of the soil. 7. The preferred combination laminated digging tool of claim 4 shatters the soil so that plant roots grow deep which utilize the deeper nutrients and minerals with healthier, higher producing plants. The preferred combination laminated digging tool of claim 4 builds soil structure to the depth of ploughing, which this layer then acts as a soil mulch above the soil that has not been ploughed, this mulch and root growth promoting soil structure below plough depth. 9. The preferred combination laminated digging tool of claim 4 changes soil colour to darker hues, allows even growth across paddocks, allows plants to change colour from yellow green of unploughed soil to blue green of ploughed soil, and allows protein levels of crops to increase. The preferred combination laminated digging tool of claim 4 releases gases from the soil including hydrogen that lowers soil acidity, radon release that allows radiation levels to reach a natural balance, hydrogen sulphide and other gases hazardous to soil biota and plants. 11. The preferred combination laminated digging tool of claim 4 re-establishes productive grasses (clover, rye) rather than barley, dwarf barley, salt tolerant succulents or nothing.

12. The preferred combination laminated digging tool of claim 4 promotes the water cycle, the vertical capillary movement of water through the soil and groundwater cycles which together promote increases in rainfall (a return to the farmer's dictum that "the rain follows the plough"), discourages frosts and inhibits erosion by impeding lateral movement of water and soil. boo: 0 o.0 as** 0 6 f