WO2004043133A1

WO2004043133A1 - Power harrow tine

Info

Publication number: WO2004043133A1
Application number: PCT/GB2003/004899
Authority: WO
Inventors: Magne Skjaeveland
Original assignee: Kverneland Asa
Priority date: 2002-11-12
Filing date: 2003-11-11
Publication date: 2004-05-27
Also published as: GB0226555D0; AU2003286239A1

Abstract

A two-part rotary harrow tine (14) has a first part (15) to be mounted on a frame (11) on a power harrow (10), and a second part (16) having a ground/soil working tip (17), (17a). The second part (16) is detachably engageable with a tip mounting portion (19) of the first part (14) via a single releasable fastener (20), and a first one of the tine parts (15), (16) has a pair of projections (21), and a second of the tine parts (15), (16) has two pairs of recesses (22, 23) each being of a size to be capable of receiving one of the projections; and a single fastening hole (27) is provided in either of the first or second tine parts, 15, 16 and a set of three fastening holes (24, 25, 26) is provided in the other of the first and second tine parts (15, 16). The harrow tine is characterised by the following features: (a) The second part (16) has opposed working tips (17, 17a) provided one at each end thereof, one of the tips (17) being in a working position and the other being in an inoperative position; (b) a middle hole (25) of the set of three fastening holes (24, 25, 26) is alignable with the single mounting hole (27) so that the single fastener 20 can be taken through the aligned holes (25, 27) to secure the first and second tine parts (15, 16) together, the second part (16) being rotatable through approximately 180°, upon loosening and/or release of the single fastener (20), so that when one tip (17) in the working position is worn, the opposite working tip (17a) can take up the working position; (c) the second tine part (16) is adjustable lengthwise, upon release of the single fastener (20), in order to increase the lengthwise projection of a worn working tip (17) from the first part (15), so as to bring either one of the outer holes (24, 26) of the set of three fastening holes (24, 25, 26) into alignment with the single fastening hole (27) to be secured thereto via the single fastener (20); and (d) in all adjusted, and rotated positioned of second tine part (16) relative to the first tine part (15), the two projections (21) are received by two of the four recesses (22, 23) to secure the tine parts (15, 16) against relative rotation about the axis of the single fastener (20).

Description

POWER HARROW TINE

This invention relates to a power harrow tine, and to a power harrow provided with a plurality of rotary harrow tines.

As is well known, power harrows are provided with rotary harrow tines which are driven in rotation so as to exert a powerful breaking-up and / or soil crumbling action, and usually are used after ploughing. Rotary harrow tines must, of necessity, be designed very robustly, both in their ground / soil engaging parts and also in the manner in which they are mounted on the harrow frame.

It is usual therefore for rotary harrow tines to be of one-piece forged construction, and also heat treated so as to increase the wear resistance of the working tip, and also the fatigue resistance of the entire tine.

The use of forged one-piece harrow tines provides durable and reliable constructions, and which work well in practice. However, even with forged constructions, tip wear does of course arise over a period of time, and with a one-piece construction, it is therefore necessary to replace an entire tine when an unacceptable amount of tip wear has occurred. The working tip is. of course, only a relatively small part of an overall one piece tine, and typically when about 30% of the overall length of the tine has worn away, the entire tine has to be removed (and disposed of as scrap) and replaced by a completely new one-piece tine.

Furthermore, existing one-piece harrow tines are mounted on the harrow frame via suitable rotary drive mountings on the frame, and when tine replacement is required, with existing designs there is not easy access to the mountings, and therefore it is not practical for tine replacement to be carried out in the field. This is because it is usually necessary to go underneath the harrow frame to reach the mountings, and therefore tine replacement normally has to take place in the workshop.

The invention therefore seeks, in one aspect, to provide an improved rotary harrow tine design which is more economical in its usage and replacement, and, in a second aspect, provides a power harrow tool in which tine tip wear is more easily repaired.

According to one aspect of the invention there is provided a two part rotary harrow tine having a first part which is adapted to be mounted on a respective rotatable mounting on a frame of a power harrow, and a second part having a ground / soil working tip, in which: the first part has a frame mounting portion at one end to be mounted on said rotatable mounting, and a tip mounting portion at its opposite end; the second part is detachably engageable with said tip mounting portion and is releasably securable thereto via a single releasable fastener; a first one of said tine parts has a pair of projections; a second one of said tine parts has two pairs of recesses, each recess being of a size to be capable of receiving one of said projections; and, a single fastening hole is provided in either one of said first and second tine parts, and a set of three fastening holes is provided in the other one of said first and second tine parts; in which:

(a) the second part has opposed working tips provided one at each end thereof, one of said tips being in a working position and the other being in an inoperative position;

(b) a middle hole of the set of three fastening holes is alignable with the single mounting hole so that the fastener can be taken through the aligned holes to secure the first and second tine parts together, the second part being rotatable through approximately 180°, upon loosening and / or release of the fastener, so that when one tip in the working position is worn, the opposite working tip can take-up the working position;

(c) the second tine part is adjustable lengthwise, upon release of the fastener, in order to increase the lengthwise projection of a worn working tip from the first part, so as to bring either one of the outer holes of the set of three fastening holes into alignment with said single fastening hole to be secured thereto via the single fastener; and,

(d) in all adjusted, and rotated, positions of the second tine part relative to the first tine part, the two projections are received by two of the four recesses to secure the tine parts against relative rotation about the axis of the single fastener. The invention therefore provides a reversibly mounted rotary harrow tine part (the second part) which has opposed working tips, either one of which can be brought to the working position when required e.g. when unacceptable wear has occurred to the tip presently in the working position. In addition, when unacceptable initial wear has taken place for both working tips, either one of the working tips can be adjusted to project a greater distance lengthwise of the first tine part, by lengthwise adjustment of the second tine part. Further reversal of the second part then allows the further worn tip to be replaced by an only partly worn tip.

The invention therefore provides a rotary harrow tine part in which four separate wearing actions may take place i.e. initial and then final wear on each working tip, before the tine part needs to be replaced.

Furthermore, by use of a single fastener (located below the level of the frame of the harrow), easy access can be had to the fastener, which allows wear-related adjustment to be carried out in the field.

Preferably, the single fastening hole is provided in the tip mounting portion of the first tine part, and the set of three fastening holes is provided in line in the second tine part.

Also, the pair of projections maybe provided on the first tine part, and the two, ._»- pairs of recesses may be provided in the second tine part. However, it should be understood that it is within the scope of the invention for the position of the projections and the recesses to be reversed.

The projections preferably comprise cylindrical pegs, and which may be formed during the formation of the first tine part e.g. by forging.

According to a second aspect of the invention there is provided a power harrow having a frame, a set of rotary harrow tines each mounted on the frame via respective rotatable mountings, and a drive train arranged to provide rotary power to rotate the harrow tines, in which each harrow tine is as defined in the first aspect of the invention.

According to a third aspect of the invention there is provided a method of adjusting a worn tip of a two part tine having a working part and a mounting part, in a power harrow as defined by the second aspect of the invention, in which: the working tine part is loosened and / or released from the mounting tine part by which the tine is mounted on the frame of the harrow; and, the working tine part is adjusted so that the opposite tine tip takes-up the working position and / or the worn tip is adjusted lengthwise relative to the mounting part so as to project by a greater distance from the mounting tine part and allow further wear to take place.

A preferred embodiment of the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a perspective illustration of a typical design of existing rotary power harrow, in which an embodiment of the invention may be provided;

Figure 2 is a detail view showing how a one-piece rotary harrow tine of known design is mounted on a rotatable mounting on a frame of the power harrow shown in Figure 1;

Figure 3 is a perspective illustration, in assembled form, of a preferred embodiment of two part rotary harrow tine according to the invention and comprises a mounting part and a harrow tine part;

Figure 4 is a view, similar to Figure 3, but showing the two parts in exploded form and also showing the non-engaging face of the harrow tine part uppermost; and,

Figure 5 also shows the two parts of the harrow tine separated from each other prior to assembly, and illustrating in more detail a co-operative arrangement of projections and pairs of recesses, and a number of different fastening holes, together providing initial wear adjustment, and final wear adjustment of each of two opposed pairs of working tips of a working part of the harrow tine i.e. to provide possibility of four different wear compensating adjustments of the harrow tine.

Referring first to Figures 1 and 2, there will be described, by way of background to the invention, a typical existing design of rotary harrow power tine, and which is normally intended to be mounted at the rear of a tractor, and from which drive power is transmitted to a number of rotary harrow tines mounted on a frame of the harrow. The harrow is designated generally by reference 10, and has a frame 11, and a series of one-piece rotary harrow tines 12 mounted on the underside of the frame 11 via respective rotatable mountings.

Figure 2 is a detail showing how a known one piece harrow tine 12 is mounted on a circular rotatable mounting 13 on the underside of frame 11. Figure 2 shows the mounting 13 partly in section. As discussed in the introduction to the specification, the use of one-piece harrow tines, for use in power harrows, provides robust and durable tines. However, given that the parts of the tines which are most exposed to wear i.e. the working tips, only constitute about 30% of the overall tine construction, when unacceptable tip wear occurs, it is then necessary to scrap the remaining 70% of the tine, and replace with a completely new replacement one-piece tine.

Also, as referred to in the introduction, the replacement of worn one-piece rotary harrow tines cannot easily be carried out in the field, and therefore usually must be carried out as part of regular maintenance in the workshop. In the event of damage to a harrow tine in the field, it is not easy to carry out individual replacement straight away.

A preferred embodiment of two part rotary harrow tine will now be described with reference to Figures 3 to 5. The rotary harrow tine is designated generally by reference 14, and has a first mounting part 15 which is adapted to be mounted on a respective rotatable mounting (e.g. 13 in Figure 2) on a frame 11 of a power harrow 10, and a second working part 16 having a ground / soil working tip 17.

The first part 15 has a frame mounting portion 18 which can be mounted e.g. by bolts onto the rotatable mounting, and also has a tip mounting portion 19 at its op osit . „ end. The second part 16 is detachably engageable with the tip mounting portion 19, and is releasably secured thereto via a single releasable fastener 20.

A first one of the tine parts (15, 16) has a pair of projections, and a second one of the tine parts has two pairs of recesses, each recess being of a size to be capable of receiving one of the projections. In the illustrated embodiment, by way of example only, projections 21 are provided on the underside of the tip mounting portion 19 of first mounting part 15, and two pairs of recesses 22, 23 are provided in the working part 16 (see the facing surface of part 16 in Figure 5). It will be noted that the pairs of recesses 22 and 23 are arranged one on either side of the fastener 20, when the latter is taken through a central one of a set of three fastening holes 24, 25 and 26, provided also in the working part 16. A single fastening hole 27 is provided in the tip mounting portion 19 of mounting part 15. Evidently, the positions of the projections 21 and the pairs of recesses 22 and 23 may be reversed, and similarly also the single fastening hole 27, and the set of three fastening holes 24, 25, 26 also may be reversed. Figure 3 shows the tine parts 15 and 16 assembled together, and Figures 4 and 5 show them separated. Also, Figure 4 shows the non-engaging face of the working part 16 uppermost and usually the threaded fastener 20 will have an integral driving head (not shown) which is engaged by a spanner or other tool to drive the thread of the fastener into driving engagement with a nut 21a, in order to clamp the parts 16, 18 together. It will be noted from Figures 4 and 5 that the working part 16 has opposed working tips, of which the one presently in the working position is designated by reference 17, and the opposite tip, presently in the inoperative position, is designated by reference 17a. There are also adjacent co-operative working edges 18 and 18a respectively.

The provision of single fastening hole 27, and the set of three fastening holes 24, 25 and 26 permits lengthwise adjustment of the working part 16 relative to the mounting part 15, when tip wear occurs, whereby the distance from any particular working tip and the fastening hole 27 can be extended, to compensate for tip wear.

The provision of the projections 21, and the pairs of recesses 22 and 23, allows the parts 15 and 16 to be securely fastened together, and held securely against rotation about the axis of the fastener 20, by reason of engagement of the projections 21 in any pair of the recesses 22_; 23, for all adjusted positions. . ...

Evidently, the working part 16 is reversible, whereby, when tip 17 becomes initially worn, loosening and / or release of the fastener 20 allows the working part 16 to rotate through 180°, and to bring the previously inoperative working tip 17a to the working position. There will continue to be engagement of the projections 21 in recesses, but in this case instead of being received by the pair of recesses 23, the projections will be received by the pair of recesses 22.

Generally, after initial wear of the tips 17 and 17a has arisen, it will then be possible to maintain use of the working part, subject to lengthwise adjustment, by bringing either fastening hole 24 or 26, into alignment with single fastening hole 27, and securement together by the fastener 20, whereby the particular partly worn working tip (17, 17a) projects by a greater distance lengthwise of the single fastening hole 27, and allows further wear to take place.

When a particular working tip has undergone two separate wearing actions, as described above, the working part may then be reversed, so that a partly worn tip can then undergo final wear. It will only be when both working tips have been subjected to these two separate wearing actions, and necessary adjustment, that the harrow tine will require to be repaired. However, it will only be necessary then to remove the working part 16, and replace it with a further working part, as the wear to which the mounting part 15 is exposed is generally less arduous in service, and repair and replacement of the working of the mounting part 15 will generally be required much less frequently.

The preferred embodiment therefore provides a reversibly mounted harrow tine part (the second part 16) which has opposed working tips, either one of which can be brought to the working position when required e.g. when unacceptable wear has occurred to the tip presently in the working position. In addition, when unacceptable initial wear has taken place for both working tips, either one of the worn tips can be adjusted to project a greater distance lengthwise of the mounting part 15 by lengthwise adjustment of the working part 16. Further reversal of the working part then allows the further worn tip to be replaced by an only partly worn tip.

Accordingly, the invention provides a harrow tine part (the working part 16) in which four separate wearing actions may take place i.e. initial and then final wear on each working tip 17, 17a, before the tine part needs to be replaced.

Fυrth π πre. by use of a single fastener 20 (located below the level of the frame -. 11 of the harrow 10), easy access can be had to the fastener 20, which allows wear-related adjustment to be carried out in the filed.

The projections 21 are preferably formed integrally with the formation of the tine part (15, 16) on which it is provided, and conveniently such part is formed by forging.

Evidently, the preferred embodiment of rotary harrow tine described above may be incorporated in a power harrow having a frame, a set of rotary harrow tines each mounted on the frame via respective rotatable mountings, and a drive train arranged to provide rotary power to rotate the harrow tines.

The invention may also allow for an easy method of adjusting a worn tip of a two part tine (having a working part and a mounting part), which is provided in a power harrow, and in which the potential adjustment steps comprise one or more of the following:

(1) the working tine part is loosened and / or released from the mounting tine part by which it is mounted on the frame of the harrow;

(2) the working tine part is rotatably adjusted so that the opposite tine tip takes-up the working position; and, (3) the worn tip is adjusted lengthwise relative to the mounting part so as to project by a greater distance from the mounting tine part and allow further wear to take place.

Claims

1. A two-part rotary harrow tine (14) having a first part (15) which is adapted to be mounted on a respective rotatable mounting (13) on a frame (11) on a power harrow (10), and a second part (16) having a ground / soil working tip (17, 17a), in which: the first part (14) has a frame mounting portion (18) provided at one end to be mounted on said rotatable mounting (13), and a tip mounting portion (19) at its opposite end; the second part (16) is detachably engageable with said tip mounting portion (19) and is releasably securable thereto via a single releasable fastener (20); a first one of said tine parts (15, 16) has a pair of projections (21); a second one of said tine parts (15, 16) has two pairs of recesses (22, 23), each recess being of a size to be capable of receiving one of said projections (21); and, a single fastening hole (27) is provided in either one of said first and second tine parts (15, 16), and a set of three fastening holes (24, 25, 26) is provided in the other of said first and second tine parts (15, 16); and further in which:

(a) the second part (16) has opposed working tips (17, 17a) provided one at each end thereof, one of said tips (17) being in a working position and the other being in an inoperative position;

(b) a middle hole (25) of the set of three fastening holes (24, 25, 26) is alignable with the single mounting hole (27) so that the fastener (20) can be taken through the aligned holes (25, 27) to secure the first and second tine parts (15, 16) together, the second part (16) being rotatable through approximately 180°, upon loosening and / or release of the fastener (20), so that when one tip (17) in the working position is worn, the opposite working tip (17a) can take-up the working position;

(c) the second tine part (16) is adjustable lengthwise, upon release of the fastener (20) in order to increase the lengthwise projection of a worn working tip (17) from the first part (15), so as to bring either one of the outer holes (24, 26) of the set of three fastening holes (24, 25, 26) into alignment with said single fastening hole (27) to be secured thereto via the single fastener (20); and, (d) in all adjusted, and rotated positions of the second tine part (16) relative to the first tine part (15), the two projections (21) are received by two of the four recesses (22, 23) to secure the tine parts (15, 16) against relative rotation about the axis of the single fastener (20).

2. A harrow tine according to claim 1, in which the single fastening hole (27) is provided in the tip mounting portion (19) of the first tine part (15), and the set of three fastening holes (24, 25, 26) is provided in the second working part (16).

3. A harrow tine according to claim 1 or 2, in which the projections (21) are provided on the facing side of the tip portion (19), and the two pairs of recesses (22, 23) are provided in the facing surface of the second working part (16).

4. A working part (16) of a two part rotary harrow tine according to any one of claims 1 to 3.

5. A power harrow (10) having a frame (11), a set of rotary harrow tines (12) each mounted on the frame (11) via respective rotatable mountings (13), and a drive train arranged to provide rotary power to rotate the harrow tines, in which each harrow tine (14) is according to any one of claims 1 to 3.

6. A method of adjusting a worn tip (17) of a two part tine having a working part (16) and a mounting part (15), in a power harrow according to claim 5, in which: the working tine part (16) is loosened and /or released from the mounting tine part (15) by which it is mounted on the frame of the harrow; the working tine part is rotatably adjusted so that the opposite tine tip (17a) takes- up the working position; and / υr, a worn tip (17, 17a) is adjusted lengthwise relative to the mounting part (15) so as to project by a greater distance from the mounting tine part (15) and allow further wear to take place.