Technical field

The present invention relates to a tool, such as a harrow tine, a cutter, a tine supporting a levelling tool, a sowing share, a roller-shaped part or some other machine part, for fastening to a beam or an axle of an agricultural machine, and to an agricultural machine having such a tool and a method for fitting a tool to an agricultural machine.

Background

The need to fit soil cultivation tools, such as harrow tines, cutters, Crossboard® tines, sowing shares or other, often resilient machine parts into profiled beams of various types has existed for as long as agricultural machinery for seeding and soil cultivation has been industrially produced. Tools have generally been fitted with the aid of various types of clasps, clamps or fittings. In certain cases, the tools have been fitted in place in one or more pre-made holes.

The currently most common method for the fitting of tools is to screw the tool in place with a fitting or with one or more clasps (non-positive connection) . One problem is that the tool, which is often vibratory in nature, will slide along the beam to which it is connected.

Harrow tines and other tools are usually given a high vibrating capacity in order to break up soil and shake off plant residues as effectively as possible, and are thus often made of spring steel. Another advantage of lending a flexibility to these tools is that they are given the ability to follow the irregularities in the ground and to spring when colliding with obstacles such as stones, rock portions, etc. — ? —

The tools which are used on agricultural machinery- are often relatively heavy and the fitting thereof is associated with manual labour in uncomfortable working positions .

SE 526 848 C2 shows a device for the releasable fastening of a spring-tine or the like for an agricultural machine having a transverse beam. The spring-tine has a fastening portion with a through hole, so that the spring-tine can be fastened to the transverse beam by guiding a bolt through the hole in the spring-tine and through a hole passing through the beam, so that the bolt can engage with a nut situated on the opposite side of the beam. It may also be desirable to give the fastening portion of the tool a certain profile, for example to increase the rigidity, but with such profiles it is harder with the state of the art to achieve satisfactory fastening.

Summary

A general object is to provide a fastening device for tools for an agricultural machine which gives improved ergonomics in respect of their fitting, allows a modified profile of the fastening portions of the tools, is cheap to produce, and is stable during operation.

The invention is defined by the appended independent patent claims. Embodiments emerge from the dependent patent claims, from the following description and from the appended drawings.

According to a first aspect, a tool is provided for releasable fastening in a support, such as a beam or an axle, of an agricultural machine. The tool has a fastening portion, configured to directly or indirectly bear against, and be fixed relative to, the support, and a working portion. The fastening portion is designed in shape and size to be inserted through a corresponding opening in the support, and the fastening portion has engagement means arranged to engage inside the support with a fixing element, so that the fastening portion is pressed against an inner surface of the support.

The tool can be a soil-cultivating tool, such as a harrow tine, a cultivator tine, a cutter, a tine supporting a levelling tool (marketed by the Applicant under the brand name CROSSBOARD®) , a sowing share, a disc holder or a roller forming element. Alternatively, the tool can be a scraper for a wheel, a disc, a roller cylinder or the like.

The support can be a beam or axle and can have a closed cross section, such as quadrilateral tubes (square or rectangular) or round tubes (circular or elliptical) . The support can be a crossbeam or a transverse axle.

That "the fastening portion is pressed against the inner surface" should be understood to mean that it bears against the inner surface, either directly or via some form of intermediate layer or surface coating.

Such a tool can be fixed very stably relative to the support, in a simple and ergonomic manner, with the aid of a single fixing element. The fact that the tool is designed for insertion into an opening in the support offers the advantage that fewer parts are required than was the case with the prior art, at the same time as the tool is prevented from sliding along the beam to which it is connected.

The above-stated engagement means can be configured for positive engagement with the fixing element and can comprise a recess which can be threaded. The recess can be in the form of a through hole or a blind hole. The engagement means can thus be integrated with the fastening portion.

Said engagement means can be configured to receive a tensile force in a direction which is distinct from a principal direction of the fastening portion. The direction can differ by more than about 45° from the principal direction, more than about 80° from the principal direction, or about 90° from the principal direction .

Said engagement means can be integrated with the fastening portion, for example by being configured in one piece with the fastening portion, or by being permanently fixed to the fastening portion in some other way.

The fastening portion can have a pretensioning member for producing a pretensioning force which acts in a separating manner between the fastening portion and the inner surface.

The above-stated pretensioning member can comprise an at least partially concave surface portion facing towards the inner surface.

The concave surface portion can be concave in a transverse plane of the implement.

The fastening portion can have a profiled stiffening, for example in the form of a longitudinal ridge or flange.

The working portion can comprise or support a harrow tine, a cutter, a Crossboard tine, a sowing share, a scraper or a roller forming element.

According to a second aspect, an agricultural machine is provided, comprising a support, such as a beam or an axle, which support has a first opening, through which a fastening portion of a tool as described above can be inserted, and a second opening, through which a fixing element can be inserted such that the fixing element engages inside the support with said engagement means of the fastening portion.

The agricultural machine, depending on the tool or tools in question, can be a harrow, a roller, a seeder, or a combined machine having at least two different soil-cultivating functions or at least one soil- cultivating and at least one feeding function, such as seeding or fertilization. The first opening can have a shape which substantially corresponds to a cross section of the fastening portion.

The fixing element can be configured to produce a tensile force upon the fastening portion.

The agricultural machine can have further pretensioning members for producing a pretensioning force which acts in a separating manner between the fastening portion and the inner surface.

The first opening can be configured such that a space is present between the fastening portion and the inner surface when the fastening portion is far enough inserted in the first opening for the fixing element, at least partially, to be able to engage with said engagement means.

The above-stated pretensioning member can be arranged on the fixing element or as a separate part.

According to one embodiment, the fastening portion can have a pretensioning member for producing a pretensioning force which acts in a separating manner between said engagement means of the fastening portion and the inner surface.

The said pretensioning member can thus be realized by one or more of a configuration of the fastening portion, a part arranged on the fixing element or a separate part, and a configuration of the opening or openings in the beam or axle.

According to a third aspect, a method of fixing a tool in a support, such as a beam or an axle, of an agricultural machine is provided. The method comprises the insertion of a fastening portion of the tool through a first opening in the support; and the insertion of a fixing element through a second opening in the support, so that the fixing element is brought into engagement inside the support with a fastening member of the fastening portion.

The method can also comprise the pressing of the fastening portion against an inner surface of the support through engagement of the fixing element with the fastening member.

The method can comprise the production of a tensile force upon the fastening portion with the aid of the fixing element.

The method can also comprise the pretensioning of the fastening portion away from the inner surface.

Brief description of the drawings

Figs. Ia and Ib show partially sectioned views of a harrow tine 1 for fitting into a support 5 in the form of a quadrilateral profile.

Fig. 2 shows a detail of the harrow tine 1 when this is inserted but not fastened in place in the support 5.

Fig. 3 shows a detail of the fastening of the harrow tine 1, 1' in the support 5, 5' .

Figs. 4a and 4b show partially sectioned views of a harrow tine 1' for fitting into a support 5' in the form of a round profile.

Fig. 5 shows a roller cylinder 10, constructed with a fastening like that in Figs. Ia and Ib.

Fig. 6 shows a roller cylinder 10' , constructed with a fastening like that in Figs. 2a and 2b.

Fig. 7 shows the roller cylinder in Fig. 6, viewed from above.

Fig. 8 shows an agricultural machine comprising both harrow tines 1, 1' and tines supporting a levelling tool 11.

Description of embodiments

Illustrative embodiments will now be described with reference to the appended drawings.

Fig. Ia shows a tool in the form of a harrow tine 1 during fitting into a support 5 in the form of a quadrilateral profile, which can be arranged as a crossbeam. The harrow tine has a fastening portion 2, as well as a working portion 3 which can support a soil-cultivating implement 4, here a reversible harrow spike. Between the fastening portion 2 and the working portion 3 can be found a resilient portion 53. The harrow tine can be configured as an S-spring or a C- spring according to the terminology in SE 526 848 C2.

The fastening portion can be provided with a threaded hole 9, which can be a blind hole (not shown) or a through hole.

The support 5 has a first opening 7, which is configured to receive the fastening portion 2, and a second opening 8, through which a bolt can be inserted. Once the fastening portion 2 is sufficiently inserted through the first opening 7, the bolt can be brought into engagement with the threaded hole 9.

The first and/or the second opening can be produced in a known manner, for example by drilling, milling, spark erosion or laser-cutting.

The first opening in the support can be configured to have substantially the same shape and size as a profile of the fastening portion. In the shown embodiments in Fig. Ia, Ib, 2, 3, 4a, 4b, 5 and 6, the fastening portions 2, 2', and hence also the first opening 7, have an elongated cross section with weakly rounded ends .

As is shown in Fig. 2, the first opening 7 can be configured such that the fastening portion, once it is inserted in the first opening, in the unloaded state, is not quite parallel with the inner surface 50 against which the fastening portion 2 is to be pressed, and such that a space S is thereby present between the fastening portion 2 and the inner surface 50. This can be realized by at least one of the edge sides 54, 55 of the first opening being directed somewhat away from the inner surface 50.

For example, a first 54 of the edge surfaces can be substantially parallel with the inner surface 50, whilst a second 55 of the edge surfaces has an angle to the inner surface 50. Together, the edge surfaces 54, 55 can define an opening which tapers in a direction in which the fastening portion 2 is inserted into the support 5. The first of the edge surfaces 54 can be the one of the edge surfaces which, depending on the configuration of the tool, is subjected to the greatest stresses, for example when the tool springs. In the shown example, the edge surface 54 is the surface which is subjected to the principal normal force when a harrow is driven forwards. A favourable distribution of the surface pressure for maximizing the service life of the tool is thereby achieved.

Alternatively, both the edge surfaces can be angled relative to the inner surface 50.

By configuring the first opening 7 in this way, the fastening portion will be "clamped down" against the inner surface 50, producing a pretensioning force which helps to give the tool a play-free fastening.

As is shown in Fig. Ia, and in detail in Fig. 2, the second opening 8 can be sufficiently large in relation to the bolt 6 for the bolt to be able to be tilted somewhat in the second opening 8. This is a way of enabling engagement between the bolt 6 and the threaded hole 9 even if the fastening portion 2 is not quite parallel with the inner surface 50 of the support 2.

In Fig. Ib, the tool is shown in the fitted state relative to the support 5. The bolt has here been tightened in the engagement with the threaded hole 9, so that the fastening portion 2 has become at least partially parallel with the inner surface 50.

As is shown in Fig. 3, the fastening portion can have a somewhat concave or cambered surface portion 51. With a concave surface portion of this kind, tightening of the bolt 6 will produce a bending of the fastening portion 2 in the plane P2-P2 (Fig. 2), producing a pretensioning force which helps to give the tool a play-free fastening. A concave surface portion can be realized by forging. As an alternative or supplement, it is also possible to produce pretensioning force through the configuration of the bolt itself. For example, the head of the bolt can be made at least partly pliable. It is also possible to arrange a spring washer or the like between the head of the bolt and the support 5.

Fig. 4a shows an alternative embodiment in which the support 5' is constituted by a round beam. In this embodiment, the end of the fastening portion 2' can have a curved portion. This portion can be curved so as in the fitted state to connect against the inner surface of the support 5' . Analogously with the embodiment according to Fig. Ia, the first opening 7 can be configured such that the fastening portion 2' is pretensioned away from the inner surface, and such that, in the course of the fitting, it is pressed against the inner surface.

Pretensioning can be realized in one or more of the ways described with reference to Fig. Ia.

Fig. 5 shows a roller cylinder 10, which is constructed with a fastening in a support 5 like that in Fig. Ia. The working portion 3' of the tool here constitutes a substantially semi-circular segment. The fastening portion 2 and its function can be configured in accordance with that which has been described with reference to Fig. Ia.

As is illustrated in Fig. 5, the fastening portion can have a profiled stiffening 52, which can be realized, for example, in the form of a longitudinal ridge or flange. Where such a profiled stiffening 52 is present, the first opening 7 can be given a corresponding shape.

Fig. 6 shows a roller cylinder 10', which is constructed with a fastening in a support 5' like that in Fig. Ib. The working portion 3' of the tool here constitutes a substantially semi-circular segment. The fastening portion 2' and its function can be configured in accordance with that which has been described with reference to Fig. Ib.

Fig. 7 shows the roller cylinder in Fig. 6, viewed from above. As can be seen from Fig. 7, a plurality of roller cylinders can be placed side by side on a support in the form of an axle 5' . According to one embodiment, two mutually adjacent roller cylinders 10, 10' can be displaced relative to each other at a predetermined angle.

Fig. 8 shows an agricultural machine in the form of a harrow, which has both harrow tines 1, 1' and tines supporting levelling tools, so-called CROSSBOARD® tines 11, which are fastened in place in supports 5, 5' in the form of crossbeams made of quadrilateral tubes.

With reference to Figs. Ia and Ib, the harrow tine is fitted into a crossbeam, for example, by the fastening portion 2 of the harrow tine being inserted through the first opening 7 in the crossbeam 2, and a bolt 6 being inserted through the second opening 8 in the crossbeam 2, so that the bolt 6 is brought into engagement inside the crossbeam with the threaded hole 9 in the fastening portion 2. Upon the initial engagement between the bolt 6 and the threaded hole, a space S, as a result of the configuration of the first opening 7, can be present between the inner surface 50 and the fastening portion (Figs. Ia, 2).

Through tightening of the bolt 6, the fastening portion 5 is drawn towards the inner surface 50, so that these come into contact and are pressed against each other and the space S is reduced or eliminated (Fig. Ib) .

When removing the harrow tine, the bolt 6 is loosened and the fastening portion 2 is pulled out through the first opening 7, whereafter a new harrow tine can be fitted.

It will be appreciated that other types of tools as described above can be fitted and removed in the same way as the harrow tine.