WO2008123830A1

WO2008123830A1 - Arrangement for seed metering at an agricultural machine

Info

Publication number: WO2008123830A1
Application number: PCT/SE2008/050394
Authority: WO
Inventors: Gert Gilstring
Original assignee: Vaderstad Verken AB
Current assignee: Vaderstad Verken AB
Priority date: 2007-04-05
Filing date: 2008-04-04
Publication date: 2008-10-16
Anticipated expiration: 2009-10-05
Also published as: SE531129C2; SE0700864L

Abstract

The invention refers to an agricultural machine comprising a seed furrow forming device 10 and a seed out feeding device (8), which via a linkage device (6) are connected with a structural member (3) in such a way that the seed furrow forming means (10) and the seed out feeding device (8) are moveable at least partly vertically. The seed out feeding device (8) comprises a seed out feeding element (803) which by means of a drive device (401) is rotatable around a seed out feeding axle (805) and adapted to, at a distance from the seed out feeding axle (805), take and release seeds (91). The linkage device (6) is adapted to provide a gearing such that a vertical component of a movement for the seed furrow forming means (10) corresponds to by a smaller vertical component of a movement for the seed out feeding device (8). The drive device (401) is adapted to increase the rotational velocity of the seed out feeding element (803) at an upward-directed relative movement of the seed out feeding device (8), and to decrease the rotational velocity of the seed out feeding element (803) at a downward-directed relative movement of the seed out feeding device (8).

Description

ARRANGEMENT FOR SEED METERING AT AN AGRICULTURAL

MACHINE

TECHNICAL AREA

The invention refers to an agricultural machine comprising at least one seed furrow forming means for forming a seed furrow in soil over which the agricultural machine moves, and at least one seed out feeding device for distributing seeds to the seed furrow, wherein the seed furrow forming means and the seed out feeding device are connected via a linkage device to a structural member, being a part of the agricultural machine, in such a way that the seed furrow forming means and the seed out feeding device are moveable at least partly vertically in relation to the structural member, in addition to which the seed out feeding device comprises a seed out feeding element which by means of a drive device is rotatable around a seed out feeding axle and adapted to, at a distance from the seed out feeding axle, take and release seeds

BACKGROUND

An agricultural machine of the type 'precision seed drill' (Eng. planter) is moved, usually towed by a tractor, over the soil that is to be drilled, and comprises a plurality of, in the lateral direction of the machine distributed, row sowing entities, each one adapted to form a seed furrow in the direction of travel of the machine, and by means of a special device place a row of seeds in the seed furrow. In order to create good conditions for the crop and yields it is important that the seeds are placed at a constant, uniform distance from each other. There is also a desire to be able to maintain a high driving velocity at sowing, decreasing the time requirement.

Patent document DE 102004045655 describes a precision seed drill with row sowing entities, each with two discs obliquely rotatable in its own direction for formation of a seed furrow, and each supported by two support wheels disposed on each side of the disc pair. Each row sowing unit is via a linkage arrangement connected with a frame of the precision seed drill so that the row sowing unit, in order to follow soil irregularities, can move vertically in relation to the frame. The precision seed drill also comprises a seed out feeding device which is adapted to distribute one seed at a time to the seed furrow and which is fixedly connected with the frame of the machine.

Like the mentioned patent document, patent document US6564730B2 describes a precision seed drill with row sowing entities, each one with two discs obliquely rotatable in its own direction for formation of a seed furrow, which row sowing entities can move vertically in relation to the frame of the precision seed drill. Seed out feeding devices, each one fixedly connected with one respectively of the row sowing entities, are each one adapted to distribute one seed at a time to the respective seed furrow.

With solutions of the types described in the mentioned patent documents an uneven seed distribution is not infrequently obtained in the seed furrows, especially at relatively high velocities for the machine. Such problems with uneven seed distribution can mean that the driving velocity at sowing must be kept relatively low.

SUMMARY

One aim with the invention is to decrease the time requirement at sowing with an agricultural machine of the type precision seed drill.

An additional aim with the invention is to permit higher driving velocities at sowing with an agricultural machine of the type precision seed drill.

Another aim with the invention is to achieve a uniform placement of seeds with an agricultural machine of the type precision seed drill. A further aim with the invention is to achieve a uniform placement of seeds with an agricultural machine of the type precision seed drill, even at relatively high velocities for the agricultural machine.

These aims are achieved with an agricultural machine of the initially described type - wherein the linkage device is arranged to provide a gearing such that a vertical component of a movement of the seed furrow forming means in relation to the structural member corresponds to a smaller vertical component of a movement of the seed out feeding device in relation to the structural member, and the drive device is adapted to increase the rotational velocity of the seed out feeding element at an upward- directed relative movement of the seed out feeding device, and to decrease the rotational velocity of the seed out feeding element at a downward-directed relative movement of the seed out feeding device.

It transpires that previous solutions have not considered that variations in the vertical velocity of the seed out feeding device contribute to a high degree to a uneven distribution of the seeds in the seed furrow. This varying vertical velocity, commonly caused by soil irregularities, means that the seeds acquire different exit velocity down towards the soil and therefore have different deviations in their placement along the seed furrow.

The combination of linkage device and drive device according to the invention contributes to considerably decrease variations in the exit velocity of the seeds. A part of this decrease is achieved by the gearing provided by the linkage device. In addition the drive device, in cases where the seed out feeding axle is not vertical, especially where the seed out feeding axle is primarily horizontal, and the seeds are released on a side of the seed out feeding axle on which the seeds are transported by the seed out feeding element with a downward-directed velocity component in relation to the seed out feeding axle, allows for the downward-directed velocity component of the seeds in relation to the seed out feeding axle to increase at an upward-directed relative movement of the seed out feeding device, and for the downward- directed velocity component of the seeds in relation to the seed out feeding axle to decrease at a downward-directed relative movement of the seed out feeding device. In this way the drive device also contributes to the difference in velocity of different seeds in relation to the seed furrow being decreased.

The decreased variation in the exit velocity of the seeds means that variations in time for displacement of the seeds from the seed out feeding device to the seed furrow are decreased. A more even seed distribution in the seed furrow at soil irregularities is thereby achieved.

While the vertical component of the movement of the seed out feeding device in relation to the structural member is less than the vertical component of the movement of the seed furrow forming means in relation to the structural member, it contributes to the seed out feeding device to a certain extent following the irregularities of the soil. This means that the difference in fall height for different seeds is decreased, which contributes to a more even seed distribution in the seed furrow.

The increased precision for the seed distribution means that the driving velocity at sowing can increase, which means that the time requirement decreases.

The combination of linkage device and drive device according to the invention has a very great advantage in that variations in the exit velocity of the seeds can be reduced radically while the drive device can be adapted to at least partly, by means of changing the rotational velocity of the seed out feeding element, adjust the vertical velocity component of the seeds in relation to the seed out feeding axle. In other words the changes in rotational velocity of the seed out feeding element can be restricted. As has been mentioned, the seed out feeding element is adapted to, at a distance from the seed out feeding axle, take and release seeds. The possibility to restrict the rotational velocity of the seed out feeding element decreases risks of the seeds being missed when they are to be taken up by the seed out feeding element (s.c. 'skips'), and/or of two seeds instead of one being released at the same time (s.c. 'doubles').

In this way a part of the variations in exit velocity of the seeds can be reduced by means of the drive device, while risks for 'skips' and/or 'doubles' are minimised, and a remaining part of the variations in exit velocity of the seeds can be reduced by means of the linkage device.

The linkage device can be designed in a range of different ways. In a preferred embodiment, the linkage device (as is exemplified below with reference to Fig. 4) comprises at least one upper and at least one lower primary linkage element (601 , 602), which is via respective first joints connected with the structural member and via respective second joints connected with a carrier device on which the seed furrow forming means is mounted, wherein the position for the respective first joint and the position for the respective second joint are separated in the intended direction of travel of the agricultural machine, in addition to which the seed out feeding device is coupled to the primary linkage elements. The coupling of the carrier device to the structural member via the primary linkage elements and the coupling of the seed out feeding device to the primary linkage elements enables an easy and reliable construction for the gearing.

Preferably, a conceptual line from the first to the second joint at at least one upper primary linkage element is essentially parallel with a conceptual line from the first to the second joint at at least one upper lower linkage element. Preferably, e.g. as in the embodiment described below with reference to Fig. 4, the distance L between the first and second joint 603, 604 at at least one upper primary linkage element 601 is essentially equally large as the distance L between the first and second joint at at least one lower primary linkage element 602. Alternatively the distance L between the first and second joint 603, 604 at the upper primary linkage elements 601 can differ somewhat from the distance L between the first and second joint 603, 604 at the lower primary linkage elements 602. Preferably, the distance between the first joint 603 at one of the at least one upper primary linkage element 601 and the first joint 603 at one of the at least one lower primary linkage element 602 is essentially equally large as the distance between the second joint 604 at the upper primary element 601 and the second joint 604 at the lower primary linkage element 602. This ensures at soil irregularities an essentially vertical movement without rotation for the carrier device on which the seed furrow forming means is mounted. In addition, the first and second joints 603, 604 at one of the at least one upper primary linkage element 601 are preferably disposed at essentially the same position in the intended direction of travel F of the agricultural machine as the first and second joints 603, 604, respectively, at one of the at least one lower linkage element 602.

Preferably, the seed out feeding device is connected with at least one of the at least one upper primary linkage element and with at least one of the at least one lower primary linkage element via a respective third joint which in the intended direction of travel of the agricultural machine is disposed in front of respective second joint and behind respective first joint. Respective third joint can thereby be disposed along a conceptual line from respective first to respective second joint. Alternatively respective third joint can be disposed at the side of a conceptual line from respective first to respective second joint. Since respective third joint in the intended direction of travel of the agricultural machine is disposed in front of respective second joint and behind respective first joint so at soil irregularities the second joint, and therefore also the carrier device, come to execute a greater vertical movement than the third joint and with this the seed out feeding device. A particularly simple and reliable mechanism for gearing is thereby provided. Preferably, the distance between respective first joint and respective third joint is essentially equally large on the upper and lower primary linkage element. It thereby becomes possible to ensure that the seed out feeding device at soil irregularities and the carrier device execute an essentially vertical movement without rotation.

The linkage device can as mentioned be designed in a range of alternative ways. In an alternative embodiment the seed out feeding device is coupled to the primary linkage elements via the carrier device. As is exemplified below with reference to Fig. 6 the linkage device thereby preferably comprises at least one secondary linkage element that via a fourth joint is connected with the seed out feeding device and via a fifth joint connected with the carrier device. The seed out feeding device can thereby via a sixth joint be connected with the structural member, or with at least one of the at least one upper primary linkage element or with at least one of the at least one lower primary linkage element.

The drive device as is explained more closely below can also be designed in a large number of alternative ways. The seed out feeding element is preferably adapted to release seeds in a release area, and the drive device and the seed out feeding device are arranged so that a vertical component of a respective increase and decrease in the velocity of the seed out feeding element in the release area, corresponding to the respective increase and decrease in the rotational velocity of the seed out feeding element, is 26-100%, preferably 36-72%, and most preferably approx. 45%, of the vertical component of the velocity of the seed out feeding device at the upward- directed and downward-directed relative movement, respectively. Over 2 Hz there exist frequencies for vertical movements of the seed out feeding device, caused by soil irregularities, with high energy content, and in the compensation range over 26% such frequencies are compensated. In practical tests it has been shown that especially energy-rich frequencies for the vertical movements of the seed out feeding device normally lie in the range 2-10 Hz and that the range 3-8 Hz contains frequencies that are considerably energy-richer than other frequencies. Calculations show that within the compensation range 26-75% irregularities in the seed distribution in the seed furrow are minimised at all frequencies in the range 2-10 Hz, and within the compensation range 36-72% irregularities in the seed distribution in the seed furrow are minimised at all frequencies in the range 3-8 Hz.

Preferably, the drive device comprises a primary drive member that displays at least one primary axis of rotation the position of which in relation to the structural member is constant,

- in addition to which the at least one primary axis of rotation is orientated primarily across the intended direction of travel of the agricultural machine and primarily horizontally,

- in addition to which the drive device comprises at least one secondary drive member adapted to be driven, directly or indirectly, by the primary drive member and to drive, directly or indirectly, the seed out feeding element.

The drive device can thereby be arranged so that the primary drive member, at out feeding of seeds from the seed out feeding device, at least in an engagement area for engagement with at least one of the secondary drive members, rotates either in a lefthand revolution or a righthand revolution viewed from the left in the intended direction of travel of the agricultural machine.

The primary drive member can comprise a primary drive wheel, and one of the secondary drive members can be a seed out feeding drive wheel that is fixedly connected with the seed out feeding element and concentric with the seed out feeding axle and adapted to be driven by the primary drive member via at least one additional secondary drive member. More specifically at least one of the at least one additional secondary drive member can comprise an endless flexible member. As an alternative at least one of the at least one additional secondary drive member can comprise a drive axle.

Preferably, the drive device is arranged so that a path angle between the direction of a movement of the seed out feeding device in relation to the structural member and an angled part of the path for the endless flexible member, at which angled part of the path the endless flexible member is adapted to be driving, is less than 90 degrees. This applies at least in a vicinity of a 'neutral position' for the seed out feeding device, i.e. in a position adopted by the seed out feeding device in the absence of soil irregularities. Furthermore the drive device can be arranged so that the path for the endless flexible member at one end of the mentioned angled part of the path extends around the primary drive wheel. That the endless flexible member is adapted to be driving at the angled end of the path means that in this part of the path it is exposed to draught forces for transference of movements from the primary drive member to the seed out feeding element. Preferred embodiments among the alternatives with the above-mentioned path angle are defined in the non- independent claims 12-14.

In certain embodiments the drive device comprises a drive unit, in addition to which the agricultural machine also comprises an electronic control 0502379- lunit, velocity determining means adapted to send to the control unit signals that indicate the velocity of the agricultural machine, and movement determining means adapted to send to the control unit signals that indicate movements of the seed out feeding device, in addition to which the control unit is adapted to control the drive unit at least partly on the basis of the signals from the velocity determining means and the movement determining means. The drive unit can thereby comprise an electric motor or a hydraulic drive element.

DRAWINGS SUMMARY

The invention will be described below in detail with reference to the drawings, in which

- Fig. 1 shows a perspective view of a precision seed drill, seen obliquely from above and obliquely from the rear, according to an embodiment of the invention, - Fig. 2 shows a side view of a row sowing unit that is a part of the precision seed drill in Fig. 1 ,

- Fig. 3 shows a perspective view of a section vertical and parallel to the direction of travel of the precision seed drill of a seed out feeding device that is a part of the row sowing unit in Fig. 2,

- Fig. 4 shows details in Fig. 2 with a linkage device, a drive device and a seed out feeding device (partly sectioned),

- Fig. 5 shows a view from above of the row sowing unit in Fig. 2,

- Fig. 6 shows a side view of a row sowing unit that is a part of the precision seed drill according to an alternative embodiment of the invention, and

- Fig. 7 shows components of the row sowing unit that is a part of the precision seed drill shown in Fig. 6.

DETAILED DESCRIPTION

Fig. 1 shows a perspective view of an agricultural machine in the form of a precision seed drill 1 according to an embodiment of the invention. The precision seed drill comprises a number, in this example eight, row sowing entities 2, each fastened on a structural member 3 comprising a cross-running steel beam. The precision seed drill is, by means of a fastening member 5 arranged at at least one free end of a longitudinal structure detail 4, adapted to be coupled behind a draught vehicle and brought in a direction indicated by the arrow F in Fig. 1. Each one of the row sowing entities 2 is adapted at movement of the machine 1 over the soil to be sown to create a seed furrow in the direction of travel of the machine, to place one seed at a time along the seed furrow in order to create a row of seeds in the direction of travel F of the machine, and to close the seed furrow..

Fig. 2 shows a side view of one of the row sowing entities 2. This is by means of a below more closely described linkage device 6 connected with the cross-running structural member 3. The row sowing unit 2 comprises a seed container 7 that communicates via a below more closely described seed out feeding device 8, adapted via a distribution member 8a (in Fig. 2 indicated by broken lines), to distribute one seed at a time to a seed furrow 9a in the soil 9.

The row sowing unit 2 comprises a carrier device 21, which comprises the distribution member 8a, and on which a seed furrow forming means comprising two rotatable discs 10 (of which only one is visible in Fig. 2), is mounted and adapted to form the seed furrow 9a. The discs 10 are in this example placed beside each other in essentially the same position in the intended direction of travel F of the machine. However the discs 10 can alternatively be displaced relative to each other in the intended direction of travel F of the machine. The discs 10 are angled relative to each other and orientated so that relative to each other they diverge backwards and upwards. The discs 10 are at use of the machine adapted during rotation to partly intrude into the soil to a predeterminable depth D, and through their mentioned relative divergence displace soil to the sides for formation of the seed furrow 9a, wherein a lower orifice on the seed out feeding device 8a is disposed just behind the intrusion of the discs 10 in the soil 9. The relative divergence of the discs backwards and upwards means that their peripheries are closest to each other in the area where they intrude into the soil.

The row sowing unit 2 in this example also comprises here not more closely described after-cultivating members 202, adapted to close the seed furrow 9a. The row sowing unit 2 can also comprise not shown in Fig. 2 fore-cultivating members, as well as protective members between the lower orifice on the seed out feeding device 8a and the intrusion of the discs 10 into the soil 9.

The row sowing unit 2 is adapted to be borne up by two support wheels 11, disposed on each side of the pair of discs 10, wherein the wheel axles of the support wheels 11 are disposed somewhat behind the disc axles in the intended direction of travel F of the machine. More precisely the support wheels 11 are disposed on each side of the pair of discs 10, viewed across the intended direction of travel of the machine 1, and in the vicinity of a respective disc 10, and are adapted at use of the machine 1 to scrape off soil and suchlike that fastens on the respective disc 10. The sowing depth D is according to known technique adjustable through adjustment of the height of the support wheels 11 in relation to the discs 10.

Fig. 3 shows a perspective view of a section vertical and parallel to the direction of travel of the agricultural machine of a seed out feeding device 8. This comprises a cylindrical case 802 and a from the case downward directed seed out feeding pipe 801, which communicates with the distribution member 8a (Fig. 2). The seed out feeding device 8 comprises a seed out feeding element 803, in the form of a round seed out feeding plate 803 that is arranged essentially concentrically in the case 802. (The appearance of the case 802 and the placement of the seed out feeding plate 803 therein can of course deviate from the example in Fig. 3.)

During use the seeds 91 are gravity-fed from the seed container 7 (Fig. 2) into the case 802 on one side of the seed out feeding plate 803. The seed out feeding plate

803 is adapted by means of a drive device described more closely below (Fig. 2, #401) to rotate in its plane around a primarily horizontally orientated seed out feeding axle 805 as is indicated in Fig. 3 with the arrow R. The seed out feeding plate 803 is adapted to in a circular, with the seed out feeding axle 805 concentric, seed transport area 806 at a distance from the seed out feeding axle 805, take, transport and release seeds. More precisely the seed out feeding plate 803 in the seed transport area 806 displays a plurality of through seed engagement holes 804 disposed at the same radial distance from the seed out feeding axles 805, in this example in the vicinity of the periphery of the seed out feeding plate 803, which seed engagement holes 804 are distributed at equal distance from each other in the circumference of the seed out feeding plate 803. A fan (not shown) communicates with the seed out feeding device 8 and the seed out feeding device 8 is adapted by means of the fan to bring about a pressure fall over a portion of the seed out feeding plate 803. Through the pressure fall a seed fastens in each seed engagement hole

804 and is transported towards the seed out feeding pipe 801. The seed out feeding device 8 is adapted to release the seeds on a side of the seed out feeding axle 805 on which the seeds are transported by the seed out feeding plate 803 with a downward- directed velocity component in relation to the seed out feeding axle 805. More precisely, at the seed out feeding pipe 801, in what here is called a release area SL (indicated in Fig. 3 by broken lines), the pressure fall is by means of a not shown pressure dividing means, e.g. in the form of a flexible wall, less than in other parts of the seed out feeding device 8. Due to the decreased pressure fall the seeds detach from the respective seed engagement holes 804, in the release area SL, and fall down through the seed out feeding pipe 801.

The drive device 401 (Fig. 2) is according to known technique arranged so that the rotational velocity of the seed out feeding element 803 around the seed out feeding axle 805 increases at an increase in the velocity of the agricultural machine, and vice versa.

The seed out feeding device 8 can within the framework for the invention be arranged in a large number of alternative ways. For example, as is also mentioned below, the seed out feeding device 8 can be orientated in alternative ways in relation to the agricultural machine, e.g. so that the seed out feeding element 803 extends primarily in a plane across the direction of travel of the agricultural machine.

Furthermore the pressure fall obtained by means of the fan over the seed out feeding element 803 can be achieved with an atmospheric pressure on one side of the seed out feeding element 803 and a pressure deficit on the other side, or with a pressure head on one side of the seed out feeding element 803 and an atmospheric pressure on the other side. Instead of seed engagement holes the seed out feeding plate 803 on one side can display at its periphery evenly distributed deepenings, each one adapted to take up a seed, in addition to which a smaller through hole in the bottom of the respective deepenings by means of the pressure fall achieves a holding fast of the respective seed. Alternatives to the pressure fall-caused uptake of seeds on the seed out feeding plate 803 can be provided. In one alternative the seed out feeding device can be arranged as something called in English 'finger pickup meter', in which a number of cam- driven 'fingers' are evenly distributed at the periphery of the seed out feeding plates, and each one adapted at rotation of the plate, by means of the cam drive, to pick up in a certain area one seed at a time and in another area release the seed.

In the embodiment described with reference to Fig. 3, in which the seed out feeding axle 805 is primarily horizontal, the release area SL is disposed primarily in the same height position as the seed out feeding axle 805, so that the seed transport area

806 has a maximal downward-directed velocity component in release area SL.

Alternatively release area SL can be disposed higher or lower than the seed out feeding axle 805, although on a side of the seed out feeding axle on which the seeds are transported with a downward-directed velocity component in relation to the seed out feeding axle.

Here reference is to Figs. 4 and 5. The linkage device 6 that is shown in these drawings is adapted to provide a gearing such that a vertical component of a movement of the seed furrow forming means 10 corresponds to a smaller vertical component of a movement of the seed out feeding device 8 (in Fig. 5 shown with broken lines). In this embodiment the linkage device 6 comprises two upper and two lower primary linkage elements 601, 602. The two upper primary linkage elements 601, likewise the two lower primary linkage elements 602, have the same orientation, are disposed in the same position heightwise and in the intended direction of travel of the agricultural machine, and are disposed a distance from each other in the cross-going direction of the agricultural machine. It should be pointed out that in alternative embodiments the linkage device 6 can display only one upper and one lower primary linkage element 601, 602, or more than two upper and more than two lower primary linkage elements 601 , 602. Each one of the primary linkage elements 601, 602 is via respective first joints 603 connected with an anchoring member 301 that is a part of the structural member 3, and via respective second joints 604 connected with a coupling portion 211 displayed by the carrier device 21. Respective second joint 604 in the intended direction of travel F of the agricultural machine is thereby disposed behind respective first joint 603. The upper primary linkage elements 601 are essentially parallel to the lower primary linkage elements 602, and have essentially the same length as the latter-mentioned. In addition the primary linkage elements 601, 602 are disposed in essentially the same position in the intended direction of travel F of the agricultural machine.

The seed out feeding device 8 is coupled to the primary linkage elements 601, 602. More specifically the seed out feeding device 8 is connected with the upper primary linkage elements 601 and with the lower primary linkage elements 602 via respective third joints 605 disposed between respective first and second joint 603, 604. In this embodiment the seed out feeding device 8 is connected with the third joints 605 via a seed out feeding structure 881 comprising intermediate linkage element 631 which extends through the third joints 605.

The distance X between respective first joint 603 and respective third joint 605 is essentially equally large on the upper and lower primary linkage elements 601, 602. Through suitable choice of this distance in relation to the distance L between respective first joint 603 and respective second joint 604 an advantageous gearing relationship between movement of the carrier device 21 and seed out feeding device is obtained. In this embodiment the distance X between respective first joint 603 and respective third joint 605 is approximately half as great as the distance L between respective first joint 603 and respective second joint 604, which gives an gearing relationship of 2: 1.

As can be seen in Fig. 2 the seed out feeding pipe 801 of the seed out feeding device is adapted to partly extend into an upper portion of the distribution member 8a in the carrier device 21 on which the seed furrow forming means 10 is mounted. The seed out feeding pipe and the distribution member thus form a telescope-like arrangement, which means that the seed out feeding device can move in relation to the distribution member, during which an effective transport of seeds from the seed out feeding device to the seed furrow is ensured.

Here reference is to Fig. 4. The row sowing unit and thereby the seed out feeding device 8 are by means of the above described linkage device moveable primarily vertically in relation to the structural member 3, as is indicated in Fig. 4 with the double arrow VF. Such movement occurs at soil irregularities at use of the agricultural machine.

In this embodiment the drive device 401 comprises a primary drive member 411 comprising primary drive wheel 411 in the form of primary chain wheel 411, which is rotatable around a primary axis of rotation 414. The primary drive member 411 is mounted on a drive device structure (not shown) fixedly connected with the structural member 3, and thus the position of the primary axis of rotation 414 in relation to the structural member 3 is constant.

The drive device 401 further comprises a secondary drive member in the form of a seed out feeding wheel 421 , which is fixedly connected with the seed out feeding element 803 and concentric with the seed out feeding axle 805. In this embodiment the seed out feeding drive wheel 421 is provided in the form of a seed out feeding chainwheel 421, and is adapted to be driven by the primary drive wheel 411 via a secondary drive member 443, comprising an endless flexible member organ 443, in the form of a chain (in Fig. 4 partly represented by dashed lines).

As is indicated by the arrow P in Fig. 4, the drive device is arranged so that the primary drive member 411 , at out feeding of seeds from the seed out feeding device 8, rotates in lefthand revolution viewed from the left in the intended direction of travel F of the agricultural machine. Furthermore, viewed in the intended direction of travel F of the agricultural machine, seed out feeding pipe 801 and the release region SL are disposed in front of the seed out feeding axle 805.

Between the seed out feeding drive wheel 421 and the primary drive wheel 411 is disposed a pulley wheel 418. The pulley wheel 418 is adapted to be in engagement with the endless flexible member 443 in a portion of its path in which it is driving, in this embodiment at its upper path between the seed out feeding drive wheel 421 and the primary drive wheel 411. Furthermore the pulley wheel 418 is arranged, through its position and its radius, so that the upper path 443 a of the endless flexible member 443 changes direction downward at the pulley wheel 418. The drive device 401 thus displays an angled part 443 a of the path for the endless flexible member 443, between the pulley wheel 418 and the primary drive wheel 411, at which angled part 443 a of the path the endless flexible member 443 is adapted to be driving.

The position of the axis of rotation for the pulley wheel 418 is fixed in relation to the seed out feeding axle 805. In this embodiment this is achieved through the seed out feeding device 8 and the pulley wheel 418 being mounted on the seed out feeding structure 881 comprising the intermediate linkage element 631.

Preferably, the drive device comprises an on the seed out feeding structure 881 mounted chain tensioner 417 for maintenance of suitable tension in the chain 443. The chain tensioner 417 is disposed between the seed out feeding drive wheel 421 and the primary drive wheel 411, and is adapted to be in engagement with the endless flexible member 443 at its lower path 443b between the seed out feeding drive wheel 421 and the primary drive wheel 411.

The distance between the primary axis of rotation 414 and the axis of rotation for the pulley wheel 418 is essentially the same as the distance between respective first and third joints 603, 605 at the respective upper and lower primary linkage element 601, 602. It should however be mentioned that in alternative embodiments the distance between the primary axis of rotation 414 and the axis of rotation for the pulley wheel 418 can be different from the distances between the first and third joints 603, 605 at the primary linkage elements 601, 602.

In the embodiment in Fig. 4, at movements of the seed out feeding element 8 in relation to the structural member 3, the direction of relative movements RB of the axis of rotation for the pulley wheel 418 is orthogonal to a conceptual line CL which cuts the first and the third joint 603, 605 at the upper (or the lower) primary linkage element 601.

A path angle α between the angled part 443 a of the path for the endless flexible member 443, and the direction RB of a movement of the seed out feeding device 8 in relation to the structural member 3, is less than 90 degrees, preferably less than 85 degrees, most preferably less than 80 degrees. This means that at a downward- directed relative movement and upward-directed relative movement, respectively, of the seed out feeding element 8, the length of the angled part 443a of the path for the endless flexible member 443 decreases and increases, respectively, so that the rotational velocity for the seed out feeding drive wheel 421 decreases and increases, respectively. Through this the position of the chain tensioner 417 is adjusted in order to compensate for the length change of the upper path 443 a for the endless flexible member 443.

A compensation KG of the seed out feeding velocity for vertical movements of the seed out feeding device 8 can be defined as a relationship between on the one hand a vertical component of an increase and decrease, respectively, of the velocity of the seed out feeding element 803 in the release area SL, corresponding to the increase and decrease, respectively, in the rotational velocity of the seed out feeding element 803, and on the other hand the vertical component of the velocity of the seed out feeding device 8 in relation to the structural member at the upward- directed and downward- directed movement, respectively. Through suitable choice of the path angle α between the angled path part 443a of the path for the endless flexible member 443, and the direction RB of a movement of the seed out feeding device 8 in relation to the structural member 3, the radius R2 for the seed out feeding drive wheel 421 and the radial distance R3 from the seed out feeding axle 805 for the seed transport area 806, an advantageous compensation KG of the seed out feeding velocity for vertical movements of the seed out feeding device 8 in relation to the structural member 3 can be achieved. More precisely in the embodiment shown in Fig. 4 the compensation KG of the seed out feeding velocity for vertical relative movements of the seed out feeding device 8 is determined according to: KG=cos(α )*R3/R2. For example with the values α=75° and R3/R2=1.5 a compensation KG of 39% is achieved.

The linkage device 6 achieves that the seed out feeding device 8 at soil irregularities executes a vertical movement that is less than that of the carrier device 21 , in that the third linkage 605 moves a way that is shorter than the corresponding way for the second linkage 604, wherein variations in the vertical velocity of the seed out feeding member 8 are restricted. In addition the drive device 401 causes variations in exit velocity of the seeds in the seed out feeding device 8 to be decreased so that variations in time for displacement of the seeds from the seed out feeding device 8 to the seed furrow 9a are decreased. In combination this contributes to an even seed distribution in the seed furrow 9a.

With reference to Figs. 6 and 7 an alternative embodiment is described here that corresponds with the embodiment described above, with the exception of the following essential differences. As can be seen in Fig. 6 the seed out feeding device 8 is coupled to the primary linkage elements 601, 602 via the carrier device 21. More precisely the linkage device 6 comprises a secondary linkage element 611 which via a fourth joint 612, a fore linkage element 615 and a connection joint 617 is connected with the seed out feeding device 8. The secondary linkage element 611 is also via a fifth joint 613 connected with the carrier device 21. Alternatively more than one such secondary linkage element 611 can be arranged in parallel on the row sowing unit 2. Furthermore the seed out feeding device 8 is connected with the structural member 3 via the connection joint 617, the fore linkage element 615 and a sixth joint 614, disposed on an anchoring member 301 that is part of the structural member 3 in a position above the primary linkage elements 601. The connection joint 617 is thus disposed between the fourth joint 612 and the sixth joint 614.

Alternative positions for the sixth joint 614 are conceivable. E.g. it can heightwise and in the intended direction of travel of the machine essentially coincide with the positions for the first joints 603 of the upper primary linkage elements 601 , or with the positions for the first joints 603 of the lower primary linkage elements 601. In an additional alternative the sixth joint 614 can be disposed on at least one of the upper primary linkage elements 601 or on at least one of the lower primary linkage elements 602.

In the embodiment in Fig. 6 the seed out feeding device 8 is fixedly connected with the seed container 7 which is fixedly connected with a fore linkage element 615 that extends to the sixth joint 614. The seed out feeding device 8 is disposed between the fourth joint 612 and the sixth joint 614, and since the latter does not execute any relative movement in relation to the structural member 3, and the fourth joint 612 executes vertical movements that are primarily equally large as that of the carrier device 21 , a down-gearing comes to be achieved in that the seed out feeding device 8 executes vertical movements that are less than those of the carrier device 21. Alternatively the seed container 7 can be fixedly connected with the structural member 3, and arranged to communicate with the seed out feeding device 8 during permission of a relative movement between the seed container 7 and the seed out feeding device 8.

The seed out feeding device 8 in Fig. 6 is by means of the connection joint 617 swingable in relation to the fore linkage element 615. The rotation of the seed out feeding device 8 is restricted by means of a guide device 821 comprising a protruding portion displayed by the seed out feeding device 8 that is adapted to move in an essentially vertical recess displayed by the carrier device 21. The connection joint 617 can alternatively be disposed on any part at all fixedly connected with the seed out feeding device 8, or directly on the seed out feeding device 8.

Fig. 7 shows schematically parts for the drive device 401 for the seed out feeding device 8 in Fig. 6. The drive device 401 comprises a with the seed out feeding device 8 (cf. Fig. 6) fixedly connected drive unit 401 in the form of an electric motor, a hydraulic drive element, or equiv. The agricultural machine also comprises an electronic control unit 451 (cf. Fig. 7), velocity determining means 452a adapted to send to the control unit 451 signals which indicate the velocity of the agricultural machine, and movement determining means 453a, 453b adapted to send to the control unit signals which indicate primarily vertical movements of the seed out feeding device 8. The control unit 451 is adapted to control the drive unit 401 at least partly on the basis of the signals from the velocity determining means 452a, 452b and the movement determining means 453a, 453b.

The velocity determining means is provided as a radar 452a, itself known within the actual technical area for velocity determination. Alternatively it can be provided as a pulse transmitter, arranged at a cogwheel or similar that is fixedly connected with and concentric with a transport wheel for the agricultural machine. On the basis of the signals from the velocity determining means 452a the drive unit 401 is controlled so that the velocity of the drive unit 401 increases at an increase in the velocity of the agricultural machine, and vice versa.

As is indicated in Fig. 6 the movement determining means comprises a position detector 453a arranged at the first joint 603 for one of the upper primary linkage elements 601 (or at some other suitable site, e.g. at one of the lower primary linkage elements 602). At vertical movements of the row sowing unit 2 in relation to the structural member 3 the position detector 453a detects the altered angle position of the upper primary linkage element 601. The control unit 451 is adapted on the basis of several sequential position determinations to determine the vertical velocity of the seed out feeding device 8.

As is also indicated in Fig. 6 the movement determining means comprises a transmitter for acceleration measurement 453b which is fixedly mounted on the row sowing unit 2. Through this, as an alternative to the position shown in Fig. 6, the transmitter 453b can be fixedly mounted directly on the seed out feeding device 8. At vertical movements of the row sowing unit 2 in relation to the soil 9, e.g. due to a local soil irregularity, the transmitter 453b detects the acceleration of the row sowing unit 2, and the control unit 451 is adapted through integration of signals from the transmitter 453b to calculate the vertical velocity of the row sowing unit 2, and thereby that of the seed out feeding device 8 in relation to the soil.

With such a combination of position detector 453a and transmitter of acceleration measurement 453b, the position detector 453a can be used to eliminate residual errors at integration of values from the transmitter for acceleration measurement 453b. It should be noted that the movement determining means can alternatively comprise only a position detector 453a, e.g. of the type described above, or only a transmitter of acceleration measurement 453b.

On the basis of the signals from the movement determining means 453a, 453b the control unit 451 controls the drive unit 401 so that the velocity of this deviates from the velocity which is determined on the basis of the signals from the velocity determining means 452a, 452b, in such a way that the rotational velocity of the seed out feeding element (Fig. 3, #803) increases at an upward-directed relative movement of the seed out feeding device 8, and the rotational velocity of the seed out feeding element (Fig. 3, #803) decreases at a downward-directed relative movement of the seed out feeding device 8. In the embodiments described above the seed out feeding axle 405, viewed in the intended direction of travel F of the agricultural machine, is disposed behind the primary axis of rotation 414. However within the framework of the invention the agricultural machine can be arranged so that, viewed in the intended direction of travel F of the agricultural machine, the seed out feeding axle 805 is disposed in front of the primary axis of rotation 414.

A range of different alternative embodiments for the linkage device and the driving are possible within the framework of the patent claims, such as e.g. those described in the Swedish patent applications no. 0700528-3 and no. 0700529-1, respectively, the contents of which are incorporated herein through this reference.

For example the linkage device 6 (cf. fig. 4) can comprise two upper and two lower secondary linkage elements, which via respective seventh joints are connected with the carrier device 21 and via respective eight joints are connected with the seed out feeding device 8, wherein respective eighth joint is displaced in the intended direction of travel F of the agricultural machine from respective seventh joint. The upper or the lower secondary linkage elements can thereby be coupled to the upper or the lower primary linkage elements 601, 602, so that when the second joints 604 move downwards in relation to the first joints 603 then the eighth joints move upwards in relation to the seventh joints, and vice versa. The secondary linkage elements can be mechanically coupled to the primary linkage elements 601, 602, or, alternatively, the upper or the lower primary linkage elements 601 , 602 can be hydraulically coupled to the seed out feeding device 8.

At embodiments where the drive device 401 is arranged so that the primary drive member 411, at out feeding of seeds from the seed out feeding device 8, rotates in righthand revolution viewed from the left in the intended direction of travel of the agricultural machine, the primary drive member 411 can comprise a chain or a belt, which is adapted to, in an area for engagement with a seed out feeding drive wheel 421 , run primarily parallel to a direction in which the seed out feeding device 8 is moveable in relation to the structural member 3.

Claims

1. An agricultural machine comprising at least one seed furrow forming means (10) for forming a seed furrow (9a) in soil (9) over which the agricultural machine (1) moves, and at least one seed out feeding device (8) for distributing seeds to the seed furrow (9a),

- wherein the seed furrow forming means (10) and the seed out feeding device (8) via a linkage device (6) are connected with a structural member (3), being part of the agricultural machine, in such a way that the seed furrow forming means (10) and the seed out feeding device (8) are moveable at least partly vertically in relation to the structural member (3),

- in addition to which the seed out feeding device (8) comprises a seed out feeding element (803) which by means of a drive device (401) is rotatable around a seed out feeding axle (805) and adapted to, at a distance from the seed out feeding axle (805), take and release seeds (91),

- characterised in that the linkage device (6) is adapted to provide a gearing such that a vertical component of a movement for the seed furrow forming means (10) in relation to the structural member (3) corresponds to a smaller vertical component of a movement for the seed out feeding device (8) in relation to the structural member (3), and

- that the drive device (401) is adapted to increase the rotational velocity of the seed out feeding element (803) at an upward-directed relative movement of the seed out feeding device (8), and to decrease the rotational velocity of the seed out feeding element (803) at a downward-directed relative movement of the seed out feeding device (8).

2. An agricultural machine according to Claim 1, wherein the linkage device (6) comprises at least one upper and at least one lower primary linkage element (601, 602), which are via respective first joints (603) connected with the structural member (3) and via respective second joints (604) connected with a carrier device (21) on which the seed furrow forming means (10) is mounted, wherein the position for respective first joint (603) and the position for respective second joint (604) are separated in the intended direction of travel (F) of the agricultural machine, in addition to which the seed out feeding device (8) is coupled to the primary linkage elements (601, 602).

5

3. An agricultural machine according to Claim 2, wherein the seed out feeding device (8) is connected with at least one of the at least one upper primary linkage element (601) and with at least one of the at least one lower primary linkage element (602) via a respective third joint (605) which in the intendedo direction of travel (F) of the agricultural machine is disposed in front of respective second joint (604) and behind respective first joint (603).

4. An agricultural machine according to Claim 3, wherein the distance (X) between respective first joint (603) and respective third joint (605) is 5 essentially equally large on the upper and lower primary linkage element

(601, 602).

5. An agricultural machine according to Claim 2, wherein the seed out feeding device (8) is coupled to the primary linkage elements (601, 602) via the o carrier device (21).

6. An agricultural machine according to any one of the preceding Claims, wherein the seed out feeding element (803) is adapted to release seeds (91) in a release area (SL), and the drive device (401) and the seed out feeding5 device (8) are arranged so that a vertical component of a respective increase and decrease in the velocity of the seed out feeding element (803) in the release area (SL), corresponding to the respective increase and decrease in the rotational velocity of the seed out feeding element (803), is 26-100% of the vertical component of the velocity of the seed out feeding device (8) at0 the upward-directed and downward-directed relative movement, respectively.

7. An agricultural machine according to Claim 6, wherein the drive device (401) and the seed out feeding device (8) are arranged so that the vertical component of the respective increase and decrease in the velocity of the seed out feeding element (803) in the release area (SL), corresponding to the respective increase and decrease in the rotational velocity of the seed out feeding element (803), is 26-75%, preferably 36-72%, of the vertical component of the velocity of the seed out feeding device (8) at the upward- directed and downward-directed relative movement, respectively.

8. An agricultural machine according to any one of the preceding Claims, wherein the drive device (401) comprises a primary drive member (411) which displays at least one primary axis of rotation (414) the position of which in relation to the structural member (3) is constant, - in addition to which the at least one primary axis of rotation (414) is orientated primarily across the intended direction of travel (F) of the agricultural machine and primarily horizontally, - in addition to which the drive device (401) comprises at least one secondary drive member (443) adapted to be driven, directly or indirectly, by the primary drive member (411) and to drive, directly or indirectly, the seed out feeding element (803).

9. An agricultural machine according to Claim 8, wherein the primary drive member (411) comprises a primary drive wheel (411), and one of the secondary drive members (421) is a seed out feeding drive wheel (421) that is fixedly connected with the seed out feeding element (803) and concentric with the seed out feeding axle (805) and is adapted to be driven by the primary drive member (411) via at least one additional secondary drive member (443).

10. An agricultural machine according to Claim 9, wherein at least one of the at least one additional secondary drive member (443) comprises an endless flexible member (443).

11. An agricultural machine according to Claim 10, wherein the drive device

(401) is arranged so that a path angle (α) between an angled part (443 a) of the path for the endless flexible member (443), at which angled part (443a) of the path the endless flexible member (443) is adapted to be driving, and the direction (RB) of a movement of the seed out feeding device (8) in relation to the structural member (3) is less than 90 degrees.

12. An agricultural machine according to Claim 11, wherein the path angle (α) is less than 85 degrees.

13. An agricultural machine according to Claim 11 , wherein the path angle (α) is less than 80 degrees.

14. An agricultural machine according to any one of Claims 11-13, wherein the drive device comprises a pulley wheel (418) which is adapted to be in engagement with the endless flexible member (443) at one end of the angled part (443 a) of its path, in addition to which the position of the axis of rotation of the pulley wheel (418) is fixed in relation to the seed out feeding axle (805).

15. An agricultural machine according to any one of the preceding Claims, wherein drive device (401) comprises a drive unit (401), in addition to which the agricultural machine also comprises an electronic control unit (451), velocity determining means (452a) adapted to send to the control unit (451) signals which indicate the velocity of the agricultural machine, and movement determining means (453a, 453b) adapted to send to the control unit (451) signals which indicate movements of the seed out feeding device (8), in addition to which the control unit (451) is adapted to control the drive unit (401) at least partly on the basis of the signals from the velocity determining means (452a, 452b) and the movement determining means (453a, 453b).