WO1995031089A1

WO1995031089A1 - Improvements in or relating to earth-working tools

Info

Publication number: WO1995031089A1
Application number: PCT/AU1995/000288
Authority: WO
Inventors: Ian Anthony Mitchell
Original assignee: Mitchtip Overseas Pty. Ltd.; Mitchtip Pty. Ltd.
Priority date: 1994-05-18
Filing date: 1995-05-17
Publication date: 1995-11-23
Also published as: IL113761A; AUPM571794A0; TW263418B; ZA954011B; IL113761A0

Abstract

A tool (10, 110, 210, 310) for working a medium such as soil comprising a rearward attachment portion (14, 114, 214, 314) connected to a forward working portion (12, 112, 212, 312) which terminates in a tip (24, 124, 224, 324). The tool has upper (20, 120, 220, 320) and lower (30, 130, 230, 330) surfaces and at least one leading edge (22, 122, 222, 322) having a recess (32, 132, 232, 332) located therein. A further at least one recess or depression (42, 142, 242, 342) is provided in the upper surface (20, 120, 220, 320) of the tool which in use collects soil and forms a wearing surface to reduce wear on the upper surface (20, 120, 220, 320). In a preferred form of the invention, the lower surface of the working portion (12, 112, 212, 312) has a channel extending rearwardly from the front tip (24, 124, 224, 324) of the tool to the rearward attachment portion. The channel in the lower surface of the tool assists in reducing the draught forces required to advance the tool through the medium and penetration of the tool within the medium.

Description

IMPROVEMENTS IN OR RELATING TO EARTH-WORKING TOOLS

This invention relates to earth-working tools for working media, such as agricultural tools used to work soil.

A major problem associated with the use of tools to work media is wear. A particular example can be seen in the practice of deep drilling.

Deep drilling is a seeding operation in which previously unworked rain- softened ground is worked to make an opening in the soil for the deposit of seeds therein. Various types of tool design have been suggested for use in such operations, but a major problem is wear. Some tools have to be replaced daily due to wear, notwithstanding that they may be formed from expensive wear-resistant alloys.

It is accordingly desirable to provide earth-working tools which are designed to suffer from reduced wear in comparison with conventional tools. With this object in mind, Australian Patent No. 638833 proposed various types of earth- working tools, including tines which have a rearward attachment portion connected to a forward working portion, the tool having upper and lower surfaces and a leading edge having a recess therein which is adapted to receive a portion of the soil or other medium as the tool is advanced through the medium, so that said medium forms a wearing edge in advance of the leading edge. Whilst the designs of agricultural tines disclosed in Australian Patent No.

638833 have very good wear-resistant properties, the working portion generally has to be of thicker form than conventional tines in order to accommodate the recess in the leading edge, which can result in an increase in the weight of the tine and the amount of material required to form the tine. Also, such a tine can require a greater draught force to advance the tine through the soil or other medium. Furthermore, although the wear on the leading edge is reduced by the recess therein, other parts of the tool such as the upper surface of the working portion or the attachment portion can suffer from excessive wear.

It is therefore desirable to provide a tool for working a medium such as soil which has a recess in its leading edge and in which at least some of the disadvantages of the previously proposed tools are ameliorated.

According to one aspect of the invention, there is provided a tool for working a medium such as soil or the like comprising a rearward attachment portion connected to a forward working portion which terminates in a front tip, the tool having upper and lower surfaces and at least one leading edge extending rearwardly and laterally from the front tip of the tool, said at least one leading edge having a recess located therein, wherein at least one further recess or depression is provided in the upper surface of the tool. Such recesses or depressions are adapted to collect some of the soil or other medium as the tool is advanced through the medium whereby the collected soil or other medium in the recess of the leading edge forms a wearing edge in advance of the leading edge and the at least one recess or depression in the upper surface of the tool also collects soil in use to form a wearing surface to reduce wear on said upper surface. The provision of at least one recess or depression in the upper surface of the tool also reduces the overall weight of the tool and the amount of material required to form the tool.

The location of said at least one recess or depression in the upper surface of the tool may be varied for different types of tool, but a wear-reducing recess or depression would normally be provided in accordance with the invention in an area that is particularly susceptible to wear. The rearward attachment portion is preferably connected to the forward working portion by an intermediate elongate shank portion, although for some applications the shank portion may be only of very short length even to the extent that it is barely identifiable as a distinct portion from the working portion and the attachment portion. In a particularly preferred embodiment, the upper surface of the tool has a raised nose which extends rearwardly from the front tip and which may merge into the attachment portion or the shank portion if provided. Such a nose may assist in penetration of the tool in the soil as it is advanced through the soil, helping to reduce the forces required to advance the tool. The nose and/or shank portion of such a tool is preferably provided with a wear-reducing recess in accordance with the invention to reduce wear on the nose and/or shank portion which would otherwise be particularly susceptible to wear.

According to another aspect of the invention, there is provided an agricultural tool for working a medium such as soil or the like comprising a rearward attachment portion connected to a forward working portion, the working portion having upper and lower surfaces and leading edges extending rearwardly and laterally from the front tip of the tool, said leading edges having recesses located therein, wherein said lower surface of the working portion has a channel extending rearwardly from the front tip of the tool to the rearward attachment portion. The channel in the lower surface of the tool assists in reducing the draught forces required to advance the tool through the medium and the penetration of the tool within the medium because as the tool is advanced, the relative rearward "flow" of the medium relative to and beneath the tool is facilitated by the channel in the lower surface.

The channel in the lower surface of the tool is preferably a central channel defined between channel walls, each of which extends rearwardly from a position adjacent the front tip to an area where the attachment portion or an intermediate shank portion, if provided, meets the working portion. In a particularly preferred embodiment, the central channel is disposed substantially underneath a central raised nose on the upper surface of the working portion, the nose extending rearwardly from the front tip to the attachment portion, or to an intermediate shank portion if provided. In accordance with a further aspect of the invention, there is provided a tool for working a medium such as soil or the like comprising a rearward attachment portion connected to a forward working portion which terminates in a front tip, the working portion having upper and lower surfaces and leading edges extending rearwardly and laterally from the front tip, a raised nose being provided on the upper surface of the working portion and having a recess or depression therein, and a channel being provided in the lower surface of the working portion substantially underneath the nose, wherein the nose and the channel extend rearwardly from the front tip to the attachment portion or to an intermediate shank portion connecting the attachment portion to the working portion. When an intermediate shank portion is present, its undersurface is preferably of concave form so as to form a continuation of the channel in the lower surface of the working portion.

Various embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a perspective view from above of a first embodiment of an agricultural tool in accordance with the invention;

Figure 2 is a front view of the tool of Figure 1; Figure 3 is a top plan view of the tool of Figure 1; Figure 4 is a side view of the tool of Figure 1; Figure 5 is an underneath perspective view of the tool of Figure 1;

Figure 6 is a rear view of the tool of Figure 1; Figure 7 is an underneath plan view of the tool of Figure 1; Figure 8 is a perspective view from above of a second embodiment of a tool according to the invention; Figure 9 is a front view of the tool of Figure 8;

Figure 10 is a top plan view of the tool of Figure 8; Figure 11 is a side view of the tool of Figure 8; Figure 12 is an underneath perspective view of the tool of Figure 8; Figure 13 is a rear view of the tool of Figure 8; Figure 14 is an underneath plan view of the tool of Figure 8;

Figure 15 is a perspective view of a third embodiment of a tool according to the invention;

Figure 16 is a front view of the tool of Figure 15; Figure 17 is a top plan view of the tool of Figure 15; Figure 18 is a side view of the tool of Figure 15;

Figure 19 is an underneath perspective view of the tool of Figure 15; Figure 20 is a rear view of the tool of Figure 15; Figure 21 is an underneath plan view of the tool of Figure 15; Figure 22 is a perspective view from above of a fourth embodiment of a tool according to the invention;

Figure 23 is a front view of the tool of Figure 22; Figure 24 is a top plan view of the tool of Figure 22;

Figure 25 is a side view of the tool of Figure 24;

Figure 26 is an underneath perspective view of the tool of Figure 22;

Figure 27 is a rear view of the tool of Figure 22; and Figure 28 is an underneath plan view of the tool of Figure 22.

The agricultural tool shown in Figures 1 to 7 of the drawings is a deep drilling point 10 having a forward working portion or head 12 and a rearward attachment portion 14 connected to the head portion 12 by an elongate shank portion 16. The attachment portion 14 is formed with an aperture 18 which enables the deep drilling point to be secured to agricultural apparatus for moving the tool through soil. Referring to Figure 4 of the drawings, the tool is normally advanced through the soil in the direction of the arrow A.

The head or working portion 12 of the tool is generally in the form of an arrow head having an upper surface 20, a lower surface 30, leading edges 22 which extend rearwardly and transversely from a front tip 24 to generally parallel side edges 26, and trailing edges 28 which extend transversely inwards to the area where the shank portion 16 joins the head or working portion 12. The tool is conveniently formed from metal, and is preferably formed from cast iron or steel.

As shown in Figures 1, 2, 4 and 5, a recess 32 is provided in each leading edge 22 so that as the tool 10 is advanced in the direction of the arrow A in Figure 4, some of the soil through which the tool is moving collects in the recesses 32, building up to a forward edge which acts as a working or wearing edge in advance of the respective leading edge 22. Having the working edges formed from the soil itself, reduces wear on the leading edges 22 of the tool, and thus the need to replace the tool so often is also reduced.

The working portion or head 12 of the tool has a raised nose 34 which extends rearwardly from the front tip 24 of the tool to meet with the elongate shank portion 16. The raised nose 34 can thus be regarded as a continuation of the elongate shank portion which has an upper surface 36, side surfaces 38 and a concave lower surface 40. Referring to Figures 1 to 3, an elongate recess or depression 42 is provided in the raised nose 34 and extends continuously into the upper surface 36 of the shank portion 16. When the tool is advanced through the soil in the direction A, soil also collects in the depression 42 to form a wearing surface which helps to protect the nose 34 and the shank portion 16 from excessive wear. It will be appreciated that in order to form recesses 32 in the leading edges

22 of the head or working portion 12, it is necessary to increase the thickness of the head in the region of the leading edges 22 as compared with conventional tools which do not incorporate wear-reducing recesses in the leading edges. This could have an adverse effect resulting in an increase in the draught forces required to advance the tool through the soil. Whilst the provision of the raised nose 34 on the upper surface of the tool assists in penetration of the tool through the soil, as shown more particularly in Figures 5 to 7, a central channel 44 is provided in the lower surface 30 of the head or working portion 12. The central channel 44 is defined between channel walls 46 each of which extends rearwardly from a point adjacent to and slightly at the side of the front tip 24 of the tool to the inward ends of the leading edges 22 where the shank portion 16 meets the head or working portion 12. The channel 44 in the lower surface of the head or working portion 12 merges into the concave lower surface 40 of the shank portion 16. Thus, as the tool is advanced through the soil, it can be considered that the soil flows rearwardly relative to the tool and part of the soil is guided to "flow" rearwardly through the channel 44. This has the effect of reducing the draught forces required to advance the tool through the soil than would otherwise be required without a channel being provided in the lower surface 30 of the head or working portion 12. Indeed, various tests have shown that a tool in accordance with the invention having recesses in its leading edges and a channel in the lower surface of the working portion as shown in Figures 1 to 7 does not require any additional draught forces to advance the tool through soil than are required for conventional deep drilling points, and the tool of the present invention has the additional advantage that wear on the tool is reduced so that the tool will last longer before requiring replacement. As shown in Figures 1 to 7, the attachment portion 14 has curved side walls

48 and the aperture 18 in the attachment portion is provided at the bottom of a sunken region 50 in the upper surface 52 of the attachment portion. It will, however, be appreciated that the attachment portion may take any other convenient form for attachment to different types of agricultural apparatus as required.

The deep drilling point 10 illustrated in Figures 1 to 7 will typically have a head or working portion that is about 2³4 inches (70mm) but it will be appreciated that agricultural tools with head or working portions of different widths may be provided for different applications, such as the embodiments of tools illustrated in

Figures 8 to 14, Figures 15 to 21 and Figures 22 to 28.

Referring to Figures 8 to 14, there is illustrated an agricultural tool 110 of similar form to the tool of Figures 1 to 7, but which differs primarily in that the head or working portion 112 is of greater width, the width of the head portion 112 between the generally parallel side edges 126 being about 5 inches (127mm). In other respects, the tool 110 is generally similar in shape and configuration to the tool 10 of Figures 1 to 7 and similar reference numerals have been applied to corresponding parts. For instance, the tool 110 essentially comprises an attachment portion 114 connected to the head or working portion 112 by an elongate shank portion 116, an aperture 118 is provided in a sunken region 150 of the attachment portion 114, the leading edges 122 of the head 112 have recesses 132 therein, a raised nose 134 is provided on the upper surface 120 of the head and extends rearwardly from the front tip 124 of the tool to meet the shank portion 116, and a central channel 144 is provided in the lower surface 130 of the head 112 extending rearwardly from the front tip 124 to the concave lower surface 140 of the shank portion 116.

As is more clearly shown in Figure 10, the tool 110 differs slightly from the tool 10 of Figures 1 to 7 in that the elongate depression 142 is mainly provided in the shank portion 116 with only the front part of the depression 142 extending into the rear part of the nose 134. This is in contrast to the tool 10 which, as illustrated particularly in Figure 3, has an elongate depression 42 formed in the raised nose 34 of the working portion 12 and the shank portion 116 in almost equal proportions. Referring to Figures 15 to 21, there is shown a modified agricultural tool or drilling point 210 which has similar features to the agricultural tools 10 and 110 of Figures 1 to 7 and Figures 8 to 14, but which differs principally in that the width of its head or working portion 212 between the generally parallel side edges 226 is only about 1 inch (25.4mm). The head 212 of tool 210 is thus only slightly wider than the elongate shank portion 216 which connects the head to the attachment portion 214. This has the effect of reducing the extent of the trailing edges 228 so that they are only barely perceptible in the tool 210. Indeed, it will be appreciated that when a narrow drilling point is required, such as illustrated in Figures 15 to 21, the side edges 226 of the head may be continuous with the sides 238 of the shank portion 216. A further difference between the tool 210 and the tools 10 and 110 is that the leading edges 222 of the tool are shorter, the side edges 226 are longer and the recesses 232 in the leading edges 222 extend into the side edges 226. Although the recesses 232 help to reduce wear on the leading edges 222, as the front part of the head portion 212 wears the leading edges 222 will, in effect, move rearwardly maintaining a point at the front tip 224 of the tool until the tool is worn to an extent that the leading edges 222 have reached the trailing edges 228. This advantageous feature is also present in the tools 10 and 110 which also have parallel side edges 26 and 126, albeit of lesser length than the side edges 226 of the tool 210.

In most other respects, the tool 210 is of similar form to the tool 10 of Figures 1 to 7 having a raised nose 234 on the upper surface 220 of the head 212, an elongate depression 242 formed partly in the raised nose 234 and partly in the upper surface 236 of the shank portion 216, a central channel 244 in the lower surface 230 of the head 212 extending rearwardly from the front tip 224 to the concave lower surface 240 of the shank portion 216, and an aperture 218 in a sunken region 250 of the upper surface 252 of the attachment portion 214.

Referring to Figures 22 to 28, there is shown another modified embodiment of a tool 310 in accordance with the invention in which the head or working portion 312 is approximately 4 inches (102mm) in width between its side edges 326. The tool 310 differs principally from the tool 10 of Figures 1 to 7 in that the shank portion 316 connecting the head portion 312 to the attachment portion 314 is much shorter than the elongate shank portion 16 of the tool 10. Also, as will be seen particularly from Figure 24, the elongate depression 342 is formed principally in the raised nose 334 on the upper surface 20 of the heads, and extends rearwardly only a short distance in the upper surface 336 of the shank portion 316.

A further difference between the tool 310 and the tools 10 and 110 is that the trailing edges 328 extend rearwardly and inwardly from the side edges 326, and then forwardly and inwardly to meet the shank portion 316, whereas the trailing edges 28 and 128 of the tools 10 and 110 extend first transversely inwardly from the side edges 26 and 126 respectively and then forwardly and inwardly to meet the respective shank portion 16 or 116. In most other respects, the tool 310 is of similar form to the tool 10 of

Figures 1 to 7 in that it has an aperture 318 provided in a sunken region 350 in the upper surface 352 of attachment portion 314, recesses 332 in the leading edges 322 of the head 312, and a central channel 344 in the lower surface 330 of the head extending rearwardly from the front tip 324 of the tool to meet the concave lower surface 340 of the shank portion 316.

Having regard to the above, it will be appreciated that the present invention provides an agricultural tool which has improved wear-resistant properties and in which the draught forces required to advance the tool through soil or other medium are not significantly greater than those required for conventional tools, and that tools in accordance with the invention may be embodied in a wide variety of different forms for different applications. It will also be appreciated that other modifications and alterations may be made to the agricultural tools described with reference to the drawings without departing from the scope and spirit of the invention. For instance, although each of the tools 10, 110, 210, 310 of the drawings is shown with a partition 54, 154, 254, 354 at the tip separating the recesses 32, 132, 232, 332 in the leading edges 22, 122, 222 and 332, the partition may be omitted so that the recesses 32, 132, 232 and 332 extend continuously from one leading edge to the other leading edge of the tool 10, 110, 210, 310.

Claims

1. A tool for working a medium such as soil or the like, comprising a rearward attachment portion connected to a forward working portion which terminates in a front tip, the tool having upper and lower surfaces and at least one leading edge having a recess located therein, the upper surface of said tool being provided with at least one further recess or depression.

2. A tool of claim 1 wherein the rearward attachment portion is connected to the forward working portion by an intermediate elongate shank portion.

3. The tool according to claim 1 wherein the upper surface of the tool has a raised nose extending rearwardly from the front tip and merging into the attachment portion.

4. The tool according to claim 3 wherein the nose portion is provided with a wear reducing recess.

5. The tool according to claim 2 wherein the upper surface of the tool has a raised nose extending rearwardly from the front tip and merging into the intermediate shank portion.

6. The tool according to claim 5 wherein at least one of the nose or shank portion is provided with a wear reducing recess.

7. The tool according to claim 1 wherein the lower surface of the working portion has a channel extending rearwardly from the front tip of the tool to the rearward attachment portion.

8. The tool according to claim 7 wherein the channel in the lower surface of the tool is a central channel defined between channel walls, each of said walls extending rearwardly from a position adjacent the front tip to an area where the attachment portion meets the working portion.

9. The tool according to claim 8 wherein the central channel is disposed substantially underneath the central raised nose on the upper surface of the working portion, the nose extending rearwardly from the front tip to the attachment portion.

10. The tool according to claim 2 wherein the lower surface of the working portion has a channel extending rearwardly from the front tip of the tool to the rearward attachment portion.

11. The tool according to claim 10 wherein the channel in the lower surface of the tool is a central channel defined between channel walls, each of said walls extending rearwardly from a position adjacent the front tip to an area where the intermediate shank portion meets the working portion.

12. The tool according to claim 11 wherein the central channel is disposed substantially underneath the central raised nose on the upper surface of the working portion, the nose extending rearwardly from the front tip to an intermediate shank portion.

13. A tool for working a medium such as soil or the like comprising a rearward attachment portion connected to a forward working portion which terminates in a front tip, the working portion having upper and lower surfaces and leading edges extending rearwardly and laterally from the front tip, a raised nose being provided on the upper surface of the working portion and having a recess or depression therein and a channel provided in the lower surface of the working portion substantially underneath the nose, wherein the nose and the channel extend rearwardly from the front tip to the attachment portion or to an intermediate shank portion connecting the attachment portion to the working portion.

14. An agricultural tool for working a medium such as soil or the like comprising a rearward attachment portion connected to the forward working portion, the working portion having upper and lower surfaces and leading edges extending rearwardly and laterally from the front tip of the tool, said leading edges having recesses located therein, wherein said lower surface of the working portion has a channel extending rearwardly from the front tip of the tool of the rearward attachment portion.

15. The agricultural tool according to claim 14 wherein the channel in the lower surface of the tool is a central channel defined between channel walls, each wall extending rearwardly from a position adjacent to the front tip to an area where the attachment portion meets the working portion.

16. The agricultural tool according to claim 15 wherein the central channel is disposed substantially underneath a central raised nose on the upper surface of the working portion, the nose extending rearwardly from the front tip to the attachment portion.

17. The agricultural tool according to claim 14 wherein the rearward attachment portion is connected to the forward working portion by an intermediate elongate shank portion.

18. The agricultural tool according to claim 17 wherein the channel in the lower surface of the tool is a central channel defined between channel walls, each wall extending rearwardly from a position adjacent to the front tip to an area where the attachment portion meets the intermediate shank portion.

19. The agricultural tool according to claim 18 wherein the central channel is disposed substantially underneath a central raised nose on the upper surface of the working portion, the nose extending rearwardly from the front tip to the intermediate shank portion.