AU652144B2 - Agricultural shares - Google Patents

Description

COMMONWEALTH OF AUSTRALIA Patents Act 1952 COMPLETE SPECIFICATION (Original) FOR OFFICE USE Application Number: PJ9257 Class Lodged: 22 March, 1990 Complete Specification Lodged: Accepted: Published: Int. Class 652144

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Priority: Related Art: TO BE COMPLETED BY APPLICANT Name of Applicant: CLAREWOOD PTY LTD FOUNDRY PTY LTD and WUNDOWIE 9 *5*55e

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0* S* S S. 55 5 0 Address of Applicant: of 34 Great Eastern Highway, South Guildford, and Hawke Avenue Wundowie, respectively, both in the State of Western Australia, Commonwealth of Australia.

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55 0 S9 Address for Service:- Wray Associates Primary Industry House 239 Adelaide Terrace Perth Western Australia 6000.

0 0O57559 2 %39 Complete Specification for the invention entitled: "Agricultural Shares" The following statement is a full description of this .nvention, including the best method of performing it known to me:- 2 THIS INVENTION relates to agricultural shares for agricultural machines such as seeding combines, scarifiers and cultivators.

Agricultural shares generally comprise a working portion which is intended for engagement with the ground and which has a front face, a rear face and two sides converging to a forward point. There is generally a land portion extending between the front and rear faces at the two sides of the share. The land portion defines the lower contact plane of the share with the ground and forms the footprint area of the share.

With agriculture shares, there is a direct relationship between the footprint area of the share and the resistance to both draft and ground penetration. Accordingly, resistance to both draft and ground penetration can be reduced if footprint area is reduced.

The present invention seeks to provide a novel and useful agricultural share which has provision to achieve a reduction in footprint area.

S 20 In one form the invention resides in an agricultural share comprising a working portion having a front face, a rear face and two sides converging to a forward point, said rear face having ground engaging portions extending along said sides, and a plurality of depressions formed in a row along 25 said ground engaging portions for providing areas of S different thickness between said front face and said rear :face from the front to the rear of said working portion for reducing the surface area of contact between said ground engvjing portions and the ground as said working portion 30 wears.

2a Preferably, the depressions are in the form of dimples.

Preferably at least some of the depressions are arranged in two rows, each row extending generally parallel to one of the two sicl-j.

00. 0 0 3 There may be further rows of depressions. The depressions in such further rows are preferably offset from depressions in the first-mentioned rows.

The depressions can serve to reduce the footprint area of the share once the sides of the share have receded to the depressions as a result of wear, particularly in cases where the depressions are in rows extending generally parallel to the sides of the share.

A reduction in footprint area is significant owing to the fact that resistance to both draft and ground penetration Sis increased with footprint area. Energy savings are therefore available if the footprint area is reduced so as to produce a reduction in resistance to both draft and S ground penetration.

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Additionally, once each side has receded to the depressions as a rsult of wear, the side becomes somewhat irregular with th, result that it becomes more effective in severing woody plants which might have otherwise been inclined to slip along the leading side as the agricultural share advanced through the ground.

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S. S In another arrangement, the depressions may accommodate elements of wear resistant material such as tungsten carbide or wear resistant ceramics.

0* The invention will be better understood by reference to a 6e the following description of several specific embodiments thereof as shown in the accompanying drawings in which:- Fig. 1 is a perspective view from above and one side of a tillage point according to a first embodiment in an unworn condition, the tillage point being in 4 an unworn condition; Fig. 2 is an underside view of the tillage point of Fig. 1; Fig. 3 is a cross-sectional view taken along the line 3-3 of Fig. 1; Fig. 4 is a view similar to Fig. 1 with the exception that the tillage point is shown in a partly worn condition and with broken lines indicating the original unworn condition of the share for reference purposes; Fig. 5 is an underside view of the tillage point of Fig. 4; Fig. 6 is a view similar to Fig. 4 with the o, exception that the tillage point is shown a condition where further wear has occurred; and Fig. 7 is an underside view of the tillage point of Fig. 6.

0* The embodiments shown in the drawings are directed to agricultural shares in the form of tillage points formed of cast material.

The tillage point according to the embodiment comprises a body 11 having a working portion 13 and a mounting portion :15. The working portion 13 comprises a front face 17, a rear face 19, and a pair of leading sides 21 which !,onverge to a forward point at nose 23. A land portion 24 extends between the front and rear faces at the two sides of the tillage point. The land area 24 defines the footprint area of the tillage point. A reinforcing rib is centrally mounted on the front face 17 and extends from the mounting portion 15 to the nose 23.

5 The mounting portion 15 comprises a mounting shank 27 of conventional form and a mounting aperture 29 provided in the mounting shank.

A plurality of depressions 31 in the form of dimples are provided on the rear face 19 of the working portion, inwardly of the land portion 24 when the tillage point is in an unworn condition. The dimples 31 are arranged in rows, each extending generally parallel to a respective one of the leading sides 21. In this embodiment, there are two such rows and the dimples in the one row are offset with respect to the dimples in the other row, as S best shown in Fig. 2 of the drawings. Additionally, in this embodiment, each row of dimples is parallel to the respective leading side but in other embodiment the rows Smay be slightly inclined to the respective sides. In such S• cases the inclination would preferably be such that the rows diverge from the respective sides in the forward direction when the point is in an unworn condition. The purpose of the inclination is to accommodate a greater 20 rate of wear at the forward part of the tillage point.

0 0 OOO06 The dimples 31 define cavities (as best seen in Fig. 3) in which soil can be trapped as the tillage point advances S. through the ground. The soil trapped in the dimples becomes packed and so serves to offer the body of the tillage point some protection against the wearing effects of oncoming soil at least in the vicinity of the dimples.

Apart from increasing the operating life of the point, this produces a further benefit 19 that it leads to the formation of a sharper cutting edge at the front of the land portion 24. This is because the region of the front face 17 adjacent the cutting edge wears at a faster rate than the corresponding region of the rear face.

6 As the leading sides 21 recede through wear, the land portion 24 approaches and eventually merges with the dimples 31. This results in the dimples 31 being present on the land portion 24, as shown in Figs. 5 and 7. The presence of the dimples on the land portion 24 reduces the footprint area defined by the land portion with the result that resistance to both draft and ground penetration is reduced. This provides for energy savings in operating agricultural machinery employing the tillage point.

As the leading edges 21 continue to recede they eventually merge with the rows of dimples with the result that the r leading sides develop an irregular edge, as shown in Figs.

•9 6 and 7. This irregular edge at each leading side is beneficial in that it serves to sever woody plant material which might otherwise slide along the leading side as the o 0 tillage point advances through the soil.

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From the foregoing it is evrlent that tillage points according to the embodiment have ie benefit of both lower resistance to both draft and ground penetration and increased operating life.

There may be situations where it is desirable to bond S elements of wear resistant material into the dimples, particularly where the tillage point is to be used in soil types which are not conducive to accumulation and packing S. of soil in the dimples. The wear resistant elements may be of any suitable material such as tungsten carbide or wear resistant ceramics.

While the embodiment has been desuribed in relation to cast tillage points, it should be understood that the invention may be applied to other agricultural shares such as pressed metal tillage points.

7 Finally, it should be appreciated that various other modifications and changes may be made to the embodiment without departing from the scope of the invention.

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Claims (8)

1. An agricultural share comprising a working portion having a front face, a rear face and two sides converging to a forward point, said rear face having ground engaging portions extending along said sides, and a plurality of depressions formed in a row along said ground engaging portions for providing areas of different thickness between said front face and said rear face from the front to the rear of said working portion for reducing the surface area of contact between said ground engaging portions and the ground as said working portion wears.

2. An agricultural share according to claim 1 wherein said depressions are in the form of dimples.

3. An agricultural share according to claim 1 or 2 wherein at least some of the depressions are arranged in two rows, each row extending from the front to the rear of said working portion. S.:i

4. An agricultural share according to claim 3 wherein there are further rows of depressions. g

5. An agricultural share according to claim 4 wherein *depressions in any one row are offset from depressions in an immediately adjacent row.

6. An agricultural share according to any one of said S..preceding claims wherein said depressions are disposed ^adjacent said two sides of said working portion.

7. An agricultural share according to any one of the preceding claims wherein the depressions accommodate elements of wear resistant material. 9

8. An agricultural share substantially as herein described with reference to the accompanying drawings. DATED this TWENTY-SECOND day of MARCH 1991 CLAREWOOD PTY LTD a nd WUNDOWIE FOUNDRY PTY LTD Applicants WRAY ASSOCIATES Perth, Western Australia Patent Attorneys for Applicant egoS 00 SO