WO2020251462A1

WO2020251462A1 - Device and method of attaching a row unit and agricultural implement comprising such device

Info

Publication number: WO2020251462A1
Application number: PCT/SE2020/050594
Authority: WO
Inventors: Jessika BOSTRÖM; Ellen EKLÖF
Original assignee: Väderstad Holding Ab
Priority date: 2019-06-10
Filing date: 2020-06-09
Publication date: 2020-12-17
Also published as: SE544226C2; SE1950683A1

Abstract

This document discloses a device for attaching a row unit (2, 2a-2f) to a frame beam (11) of an agricultural implement (1). The device comprises an attachment frame (60) having a base portion (601 ), and at least one engagement portion (602a, 602b; 603a, 603b). The engagement portion (602a, 602b; 603a, 603b) is configured to at least partially surround the frame beam (11) or a part thereof and to engage the frame beam (11) by at least one abutment surface (6061, 6071) facing the base portion (601). A biasing device comprising at least one wedge body (61a, 61 b) is displaceable along a plane (P) of the attachment frame (60), which faces the frame beam (11), between an open position and a locking position, such that the wedge body (61a, 61b) ), in the locking position, provides a locking force between the attachment frame (60) and the frame beam (11), whereby the beam (11) is clamped between the wedge body (61a, 61 b) and the abutment surface (6061, 6071). The document also discloses an agricultural implement comprising a plurality of such devices and a method for mounting a row unit to an agricultural implement.

Description

DEVICE AND METHOD OF ATTACHING A ROW UNIT AND

AGRICULTURAL IMPLEMENT COMPRISING SUCH DEVICE

Technical field

This document relates to a device for attaching a row unit to a support structure, such as a frame beam, of an agricultural implement, and a method for attaching a row unit to a support structure, such as a frame beam.

Background

Agricultural implements intended for feeding granular material to ground over which the agricultural implement travel, such as seed drills or machines for distribution of fertilizer and / or pesticides, may comprise a plurality of row units.

Each row unit has functionality to open a groove in the ground, feed material to the groove and then close the groove. Granules can be fed individ ually, such as in precision seeding, or volumetrically. The row unit may comprise a feeder device, for example in the form of a singulating device, as well as a container or buffer for the granular material.

Each row unit can usually operate independently of the other row units. Optionally, the feed rate of the row units can be controlled individually, for example, to compensate for speed variations between row unit and ground, as occurs in curve-taking.

An agricultural implement can include a number of row units. For example, seed drills presently available on the market can have between 4 and 24 row units.

It is desirable to be able to adjust the agricultural implement so that different row spacings can be used for sowing different crops.

For this purpose, it is known to arrange a plurality of row units along a transverse frame beam of the agricultural implement. Line spacing can then be achieved by moving the row units along the frame beam. At the desired position, the row unit is usually locked relative to the frame beam by means of a clamping connection, which is usually operated by means of some form of bolt. Examples of such connections are disclosed in US2015150184 AA and US2018146609A A.

There is a need to provide an improved attachment of the row unit to the frame beam, and especially then an attachment that facilitates for a user to adjust the row spacing of the agricultural implement.

Summary

An object is thus to provide a device for attaching a row unit to a frame beam, which facilitates for a user to adjust the row spacing. A particular object is to provide a safe and reliable device, which reduces the time it takes to reset the agricultural implement.

The invention is defined by the appended independent claims.

Embodiments are apparent from the dependent claims, from the following description and from the drawings.

According to a first aspect, there is provided a device for attaching a row unit to a frame beam of an agricultural implement, comprising an attach ment frame which has a base portion and at least one engagement portion. The engagement portion is configured to at least partially surround the frame beam or a part thereof, and to engage the frame beam by means of at least one abutment surface facing the base portion. A biasing device, which comprises at least one wedge body, which is displaceable along a plane of the attachment frame, which faces the frame beam, between an open position and a locking position, such that the wedge body, in the locking position, provides a locking force between the attachment frame and the frame beam, whereby the beam is clamped between the wedge body and abutment surface.

A "wedge body" is a body that is wedge-shaped, or which has a wedge-shaped portion. The wedge body preferably has two flat surfaces which form an acute angle relative to each other. The angle can be selected to be small enough to allow self-locking of the friction joint. Alternatively, the angle can be selected too large to allow self-locking, whereby the wedge bodies can instead be locked using the crank body or its lever. The wedge body thus provides an expanding locking force between the attachment frame and the frame beam.

Preferably, the angle is on the order of 1 -30 degrees, most preferably 5-15 degrees. The wedge body may be formed as a straight prism, with a constant cross-section at least at its wedge-shaped portion.

With the "surround the frame beam or a part thereof is meant that the attachment portion extends partially or completely around the beam cross section. Preferably, this may mean that the engagement portion allows such an engagement with the beam, that the attachment frame can be removed only by a displacement of the attachment frame along the longitudinal direc tion of the beam. However, the engagement portion should be designed to have a sufficient clearance between the beam and the engagement frame so that displacement along the beam is facilitated.

For example, the engagement portion may completely enclose the beam, i.e. extend around the entire cross-sectional area of the beam, just like a U-shaped cramp.

Alternatively, the engagement portion may extend around a portion of the cross-sectional area of the beam, to engage with an opposite side of the beam, with a shoulder of the beam, or with a recess in the beam.

The abutment surface may be local, i.e. formed only over a portion of the attachment frame width, such as over less than 25%, or less than 10% of the attachment frame width.

Alternatively, the abutment surface may extend over a substantial portion of the attachment frame width, such as over at least 75% of the attachment frame width, or at least 90% of the attachment frame width.

By utilizing a wedge body acting between the attachment frame and the frame beam, a very large clamping force can be achieved.

The attachment frame may have two engagement portions extending from respective ends of the base portion.

The engagement portions may extend substantially perpendicular from the base portion, and preferably beyond the plane. The engagement portions may be spaced vertically and / or horizontally.

An abutment portion may extend between the engagement portions. The abutment portion may be formed by the base portion or a shank portion.

The biasing device may comprise a crank body and a link, wherein the link is pivotally connected to an eccentric portion of the crank body and to the wedge body, so that the displacement of the wedge body is controllable by a rotation of the crank body.

By means of the crank body and the link, the displacement of the wedge body, which can be substantially linear, can be controlled by means of a rotary motion.

The device may further comprise a lever or lever bracket integrated with the crank body.

By integrating a lever or lever bracket with the crank body, it is possible to provide a sufficiently large torque on the crank body for the wedge body to be brought into or out of engagement.

The crank body may be rotatably arranged relative to the base portion.

The crank body can be rotatably attached to the base portion by means of a shaft arranged in a hole in the crank body and the base portion.

Alternatively, a shaft may be integrated with the base portion or with the crank body and arranged in a hole in the other of the crank body and the base portion.

The crank body may be displaceable relative to the base portion.

By making the crank body displaceable relative to the base portion, and in particular displaceable in a plane parallel to the base portion, it is possible to ensure that the same force is applied to more than one wedge body. Because the crank body is fluidly mounted to the base portion, the crank body can move, so that the wedge bodies act with each other as counterholds, instead of the crank body as counterhold for either wedge body.

The crank body may be mounted by means of an elongate hole formed in the base portion.

The link may be displaceably connected to the wedge body.

By the link being " displaceably connected" is meant that the link's attachment to the wedge body is displaceable. This can be accomplished by either the wedge body or the link having an elongate hole in which a pin is provided.

The device may further comprise an adjusting device, for adjusting the displaceability of the link relative to the wedge body.

For example, the displaceability of the link relative to the wedge body can be limited to ensure that the wedge body does not engage too late.

With such adjustment devices on at least one wedge body, it is possible to balance the engagement of the wedge bodies.

The biasing device may comprise at least two wedge bodies which are displaceable in different, preferably opposite, directions.

The wedge bodies may be displaceable in substantially opposite directions.

Preferably, the wedge bodies are displaceable so that they move in substantially opposite directions, i.e. both are pushed outwardly when the biasing device is actuated and both are pulled inwardly when the biasing device is released.

This is particularly preferred in connection with the use of a crank body for the movement of two or more wedge bodies. Alternatively, a crank body can be provided for each wedge body.

It is conceivable to provide more than two wedge bodies, for example three wedge bodies which are displaceable in three directions which deviate 120 degrees from each other. In such a system, the crank body can be fluidly mounted in more than one direction, for example in that its mounting hole is circular, but larger than its axis.

The attachment frame may have a ramp surface cooperating with the wedge body.

The ramp surface may have an angle relative to the frame beam surface, which is substantially the same as the wedge body wedge angle.

The abutment surface may have a friction-reducing coating.

By providing the abutment surface with a friction-reducing coating, dis placement of the row unit along the beam is facilitated. In addition, the risk of damage to the beam's surface layer, which can be painted, is reduced. The wedge body may have a first surface substantially parallel to the surface of the frame beam facing the base portion and a second surface constituting a ramp surface.

According to a second aspect, there is provided an agricultural imple ment comprising a frame and a plurality of row units, wherein the frame com prises a transverse frame beam, and wherein the row units are attached to the frame beam by a respective device according to any of the preceding claims.

The frame beam may have a friction-reducing coating on at least one surface portion against which abutment between the attachment frame and the frame beam.

The abutment may be present when the row units are in a fixed state, or during displacement of a row unit relative to the frame beam.

According to a third aspect, there is provided a method of attaching a row unit to a frame beam of an agricultural implement, comprising arranging an attachment frame in at least partially enclosing engagement with the frame beam, arranging a wedge body in engagement between the attachment frame and the frame beam, and displacing the wedge body to provide a clamping force between the attachment frame and the frame beam.

The clamping force is an expanding force between the attachment frame and the frame beam.

An eccentric portion of a crank body may be connected to the wedge body via a link, wherein the displacement of the wedge body is accomplished by turning the crank body.

Brief description of the drawings

Fig. 1 shows a perspective view of an agricultural implement in the form of a precision seed drill.

Fig. 2 shows a perspective view of a part of an agricultural implement, comprising a row unit attached to a frame beam.

Fig. 3 shows a perspective view of a row unit.

Fig. 4 shows an exploded view of an attachment device. Fig. 5 shows a sectional view of the attachment device, seen in a vertical plane perpendicular to the frame beam.

Fig. 6 shows a perspective view of the attachment device in the open state.

Fig. 7 shows a perspective view of the attachment device in the locked state.

Fig. 8a shows a sectional view of the attachment device, seen in a horizontal plane, and in the open state.

Fig. 8b shows a sectional view of the mounting device, seen in a vertical plane parallel to the frame beam, and in the open state.

Figure 9a is a sectional view of the attachment device, viewed in a horizontal plane and in the locked state.

Fig. 9b shows a sectional view of the attachment device, seen in a vertical plane parallel to the frame beam, and in the locked state.

Fig. 10 shows a plan view of the attachment frame, seen from the front.

Detailed description

Fig. 1 shows a perspective view of an agricultural implement 1 in the form of a precision seed drill.

The agricultural implement 1 comprises a number, in this example six, output units 2a-2f, also termed "row units", which are arranged side by side and suspended to a transverse beam 11 forming part of a frame, which is supported by two wheels 3a, 3b. The agricultural implement 1 is, by means of a fastening means 5 arranged at a free end of a longitudinal drawbar 10, arranged to be coupled to a towing vehicle, such as a tractor and intended to be driven in a forward direction indicated by the arrow F.

Each of the output units 2a-2f has a sowing device which is arranged, in the movement of the agricultural implement 1 over the ground to be sown, to form a seed furrow in the driving direction of the agricultural implement 1 , to dispense material, in the illustrated case seed, and possibly also fertilizer and / or pesticide, to the seed furrow, after which this is closed. In the example shown, each output unit 2a-2f has its own drive device (not shown), which may include an electric motor, as well as a local control unit, which controls the drive device and can act as an interface to a central control unit.

Output devices 2a to 2f may be movably secured to the agricultural implement frame 10, 11. For example, the output devices 2a to 2f may be secured via a parallel linkage 4 which can be spring loaded and / or adjustable, either manually or by means of an actuator, such as a hydraulic actuator.

Thus, in the example shown, the seed drill is a so-called precision seed drill, i.e. a seed drill that singles out the granules, such as seeds, which are to be distributed, and places them one by one at a certain distance in the forward direction.

It will be appreciated that the invention may also be applied to other types of seed drills, such as volumetric drills, and especially to drills where the row units operate individually or in groups with respect to the output amount of material per unit length.

In addition, the invention can be applied to machines for distributing pesticides and / or fertilizers, in solid or liquid form, provided, also, that the dispensing nozzles are individually or group wise controllable.

Fig. 2 shows a perspective view of a row unit 2, which is attached to a transverse frame beam 11 by means of an attachment device 6, seen obliquely from behind. A parallel linkage 4 extends between the attachment device and the row unit 2.

In Figure 3, the row unit 2 with the parallel linkage 4 and the

attachment device 6, are shown seen obliquely from the front.

Figure 4 shows an exploded view of the attachment device 6. The attachment device 6 comprises an attachment frame 60 which includes a base portion 601 which may be substantially planar and formed from a metal sheet of sufficient thickness; a pair of shank portions 605a, 605b, which are also substantially planar and may be formed of respective metal sheets of sufficient thickness; and a pair of abutment portions 606, 607, which may also be formed by the respective metal sheets of sufficient thickness.

The metal sheet thickness of the attachment portions and the base portion may be on the order of 8-20 mm, preferably 9-15 mm. For the abutment portions, the sheet thickness may be slightly smaller, for example 5- 10 mm.

The shank portions 605a, 605b may be integrated, such as

permanently joined, to the base portion 601 by means of bolt / screw, weld or solder. Alternatively, the shank portions 605a, 605b and the base portion 601 may be integrally formed, for example, as a cast article.

The abutment portions 606, 607 may be joined with the leg sections 605a, 605b by means of welding or soldering.

Alternatively, the base portion 601 and one, or both, of the abutment portions 606, 607 may be formed from a single metal sheet which is bent in substantially C shape.

The base portion 601 may have a through hole 604 for mounting the biasing device. The hole can be elongated. In the example shown, the hole 604 is elongated in a horizontal direction. A sleeve 66 and a bolt 67 can be used for said mounting of the biasing device.

The shank portions 605a, 605b have respective engagement portions 602a, 602b; 603a, 603b, which are designed to enclose at least a portion of the frame beam 11. In the example shown, the engagement portions are specially designed to partially enclose a beam of "hourglass-shaped" cross- section, as shown in Fig. 5, i.e. a beam whose cross-section exhibits shoulders.

The shank portions 605a, 605b may have a beam interface, in the form of one or more surface portions located in the same plane P and facing one and the same surface portion 110 of the beam 11.

The engagement portions 602a, 602b; 603a, 603B extend beyond the plane P, and has abutment surfaces which face the plane P.

In the shank portions 605a, 605b, recesses 608a, 608b are formed.

The recesses may extend perpendicularly inwardly from the plane P. At the bottom of the recesses, respective ramp surfaces 610a, 610b may be present. The ramp surfaces is thus spaced from the plane P in that they are recessed from the plane P. In conjunction with the recesses 608a, 608b, horizontal support plates 609a, 609b may be provided. The support plates can help control the movement of the wedge bodies. The biasing device may further comprise a crank arrangement comprising a crank body 62 which is pivotally mounted relative to the base portion 601 via a mounting hole 621. The crank body 62 may have a pair of eccentric holes 622a, 622b and a lever 623.

The wedge bodies 61 a, 61 b have an engagement portion 612 with a wedge surface 6121 and a flat surface 6122; and a coupling portion 613, which may be recessed relative to the engagement portion, to leave space for the links 63a, 63b. The wedge bodies can be made of metal, preferably steel.

The wedge bodies 61 a, 61 b may be connected to the crank body 62 via links 63a, 63b. Each link may be pivotally connected to the wedge body 61 a, 61 b and with the crank body 62, respectively. The pivotal connections may be provided by means of respective pin 64 engaging hole 6133 in the wedge body engagement portion 613 and with eccentric hole 622a, 622b in the crank body 62. The links can be designed as elongated flat plate parts with mounting holes at respective ends.

The wedge bodies 61 a, 61 b may be movable in directions parallel to the plane P. The expanding force provided by the ramp bodies of the wedge bodies may have a greatest force component in a direction perpendicular to the plane P.

Links 63a, 63b and pins 64 may be sized to allow certain clearance, especially in a horizontal plane, to allow the wedge bodies to be displaced laterally slightly when engaging the ramp surfaces 610a, 610b.

The hole 6133 in the wedge body may be elongated, to allow the pin 64 to be slightly displaced relative to the wedge body.

The beam 11 shown in Fig. 5 has a cross section, which means that it is formed to have a pair of opposite sides with retracted or recessed surface portions 111 and a pair of opposite surface portions 110 which are flat.

A beam with hourglass-shaped cross-section can be formed by rolling a beam blank with rectangular or square cross-section in a manner known per se. Such hollow and hourglass-shaped beam profiles find particular application when it is desirable to be able to utilize the flanges formed for engagement with cramps or other types of mounting devices, and / or when it is desirable to be able to recess, for example, bolt heads or other fasteners so that they do not interfere with e.g. cramps or mounting devices of a type extending around all or part of the beam, providing greater freedom to mount equipment, such as row units, along the length of the beam.

The retracted sides 111 are delimited by ramp surfaces 112, 113, whose normal directions form an angle of 100-170 degrees relative to the normal directions of the flat sides, preferably 110-160 degrees.

As shown in Fig. 5, engagement surfaces 6061 , 6071 of abutment portions 606, 607 and / or of engagement portions 602a, 602b, 603a, 603b engage the ramp surfaces 112, 113 of the frame beam 11.

The base portion 601 may be substantially parallel to a front surface 110 of the frame beam 11.

As shown in Fig. 5, the wedge portions operate between the

attachment frame 60 and the front surface 110 of the beam, and more specifically between the ramp surfaces 610a, 610b of the attachment frame 60 and the front surface 110.

It will be appreciated that the engagement portions may be designed to completely or partially enclose a beam of circular or square cross-section; or to engage with, for example, a flange pair of an I-beam.

In Fig. 6 the mounting device is shown in mounted and open state. The crank body 62 is pivotally mounted relative to the base portion 601. The links 63a, 63b connect eccentric holes 622a, 622b of the crank body 62 to the wedge bodies 61 a, 61 b. As shown in Fig. 6, the crank body 62 is in a state where the eccentric holes 622a, 622b are laterally retracted, and thus the links 63a, 63b and the wedge bodies 61 a, 61 b are laterally retracted.

The corresponding view is shown in Figures 8a and 8b, where it can be seen that the wedge bodies 61 a, 61 b in this state have little or no engage ment with the ramp surfaces 610a, 610b. Thereby, little or no expanding force is generated between the attachment frame 60 and the beam 11.

In Figures 7 and 9a-9b the attachment device is shown in the locked state. As can be seen here, the crank body 62 is in a state where eccentric holes 622a, 622b are in their laterally outermost extreme positions, and thus also wedge bodies 61 a, 61 b are in their laterally outermost extreme positions. Corresponding views are shown in Figures 9a and 9b, where it can be seen that the wedge bodies 61 a, 61 b in this state have extensive, or com plete, engagement with the ramp surfaces 610a, 610b. Thus, a strong expan ding force is generated between the attachment frame 60 and the beam 11.

With the abutment surfaces 6061 , 6071 engaged with corresponding surfaces 112, 113 of the beam 11 as counterhold, the beam 11 , in the locked position, will be clamped between the abutment surfaces 6061 , 6071 and the wedge bodies 61 a, 61 b.

Fig. 10 shows the horizontally elongated hole 604 in the base portion 601. Because the bore is elongated, the crank body 62 is limited displaceable relative to the base portion 601 , so that the horizontal position of the crank body relative to the base portion 601 can be determined by the engagement of the wedge bodies 61 a, 61 b with the ramp surfaces 610a, 610b. Thus, all the horizontal force will act between the wedge bodies, via the links and the crank body, instead of acting between one of the wedge bodies and the crank body 62. It is thus possible to ensure that both wedge bodies are fully engaged, since the risk of one wedge body going in engagement before the other, is reduced.

The corresponding effect can be achieved by means of an elongated, or slightly too large, hole in the crank body 62.

Thus, this provides an opportunity to calibrate the attachment device 6 to compensate for manufacturing tolerances.

As mentioned above, the wedge bodies may have an elongate engagement hole 6133, in which the pin 64 connecting the wedge body 61a, 61 b to the link 63a, 63b is received.

In addition, an adjusting screw 614 can be provided in the wedge body 61 a, 61 b, to limit the movement of the pin along the extent of the hole 6133.

By screwing in the adjusting screw 614, it is possible to set at what positions the pin 64 should start pressing the wedge body 61 a, 61 b. For example, the adjusting screw 614 can be screwed all the way in to lock the pin at its innermost position.

This thus provides an additional opportunity to calibrate the attachment device 6, to compensate for manufacturing tolerances. In the example shown, the wedge bodies are offset in horizontal directions parallel to the longitudinal direction of the frame beam. It will be appreciated that the wedge bodies may instead be displaceable in other directions, which are preferably parallel to the surface of the frame unit facing the row unit, but which do not have to be horizontal. For example, the wedge bodies may be displaced in vertical directions.

Mounting a row unit with attachment device 6 as shown herein can proceed as follows.

The biasing device is placed in its open position, i.e. with the wedge bodies 61 a, 61 b retracted.

Then, the row unit is slid onto the frame beam along its longitudinal direction, with the engagement portions 602a, 602b; 603a, 603b in

engagement with the shoulders of the hourglass-shaped beam. The row unit 2 is then displaced to the desired lateral position.

When the desired position is reached, the biasing device is actuated, for example, by rotating the lever 623 or an extension thereof (not shown) so that the crank body 62 is rotated about the shaft 66, 67, the links 63a, 63b pushing the wedge bodies 61 a, 61 b so that they are brought outwardly. The ramp surfaces 6121 of the wedge bodies then engage the ramp surfaces 610a, 610b of the attachment frame, so that the surfaces 6122 of the wedge bodies are pressed against the surface 110 of the beam facing the row unit 2. Hence, the base portion 601 is pressed away from the beam 11 and the engagement portions 602a, 602b; 603a, 603b and any abutment portions 606, 607 act as counterholds.

When sufficient fastening force has been achieved, the lever 623 can be locked relative to the attachment frame, to prevent the biasing device from being unintentionally released, for example due to vibrations.

When adjusting positions of the row units, biasing devices may be released, the row unit moved to the desired new position, whereupon the biasing device is actuated again.

A friction-reducing coating 615 may be provided either on the abutment surface 6061 , 6071 , or on the surface portion(s) of the frame beam 11 against which some portion of the attachment frame 60 will abut, or on both abutment surfaces and frame beam.

Claims

1 . Device for attaching a row unit (2, 2a-2f) to a frame beam (1 1 ) of an agricultural implement (1 ), comprising:

an attachment frame (60), which has a base portion (601 ), and at least one engagement portion (602a, 602b; 603a, 603b),

wherein the engagement portion (602a, 602b; 603a, 603B) is configured to at least partially surround the frame beam (1 1 ) or a part thereof, and to engage the frame beam (1 1 ) by means of at least one abutment surface (6061 , 6071 ) facing the base portion (601 ),

characterized by

a biasing device, which comprises at least one wedge body (61 a, 61 b), which is displaceable along a plane (P) of the attachment frame (60), which faces the frame beam (1 1 ) between an open position and a locking position, such that the wedge body (61 a, 61 b), in the locking position, provides a locking force between the attachment frame (60) and the frame beam (1 1 ), whereby the frame beam (1 1 ) is clamped between the wedge body (61 a, 61 b) and the abutment surface (6061 , 6071 ).

2. The device according to claim 1 , wherein the attachment frame has two engagement portions (602a, 602b; 603a, 603b) extending from respective ends of the base portion (601 ).

3. The device according to claim 2, wherein an abutment portion (606, 607) extends between the engagement portions (602a, 602b; 603a, 603b).

4. The device according to any one of claims 1 -3, wherein the biasing device comprises a crank body (62) and a link (63a, 63b), wherein the link is pivotally connected to an eccentric part (622a, 622b) of the crank body (62) and to the wedge body (61 a, 61 b), such that the displaceability of the wedge body (61 a, 61 b) is controllable by a rotation of the crank body (62).

5. The device according to claim 4, further comprising a lever (623) or lever bracket integrated with the crank body (62).

6. The device according to claim 4 or 5, wherein the crank body (62) is rotatably arranged relative to the base portion (601 ).

7. The device according to claim 6, wherein the crank body (62) is displaceable relative to the base portion (601 ).

8. The device according to claim 7, wherein the crank body (62) is mounted by means of an elongate hole (604) formed in the base portion (601 ).

9. The device according to any one of claims 4 to 8, wherein the link (63a, 63b) is displaceably connected to the wedge body (61 a, 61 b).

10. The device according to claim 9, further comprising an adjusting device (614), for adjusting the displaceability of the link relative to the wedge body.

11. The device according to any one of the preceding claims, wherein the biasing device comprises at least two wedge bodies (61 a, 61 b) which are displaceable in different, preferably opposite, directions.

12. The device according to any one of the preceding claims, wherein the attachment frame (60) has a ramp surface (610a, 610b) cooperating with the wedge body (61 a, 61 b).

13. The device according to any one of the preceding claims, wherein the abutment surface (6061 , 6071 ) has a friction-reducing coating.

14. The device according to any one of the preceding claims, wherein the wedge body (61 a, 61 b) has a first surface (6122) which is substantially parallel to the surface of the frame beam facing the base portion and a second surface (6121 ) constituting a ramp surface.

15. An agricultural implement, comprising a frame and a plurality of row units,

wherein the frame comprises a transverse frame beam (11 ), and wherein the row units (2, 2a-2f) are attached to the frame beam (11 ) by a respective device according to any one of the preceding claims.

16. The agricultural implement according to claim 15, wherein the frame beam, on at least one surface portion against which abutment exists between the attachment frame and the frame beam, has a friction-reducing coating.

17. A method of attaching a row unit (2, 2a-2f) to a frame beam of an agricultural implement, comprising:

arranging an attachment frame (60) in at least partially enclosing engagement with the frame beam (11 ),

arranging a wedge body (61a, 61 b) in engagement between the attachment frame (60) and the frame beam (11 ), and

displacing the wedge body (61 a, 61 b) to provide a clamping force between the attachment frame (60) and the frame beam (11 ).

18. The method according to claim 17, wherein an eccentric portion (622a, 622b) of a crank body (62) is connected to the wedge body (61 a, 61 b) via a link (63a, 63b), and wherein the displacement of the wedge body (61 a, 61 b) is accomplished by turning the crank body (62).