GB2164232A

GB2164232A - A seed drill

Info

Publication number: GB2164232A
Application number: GB08520369A
Authority: GB
Inventors: Bernd Gattermann; Rudolf Gehrke
Original assignee: Amazonen Werke H Dreyer SE and Co KG
Current assignee: Amazonen Werke H Dreyer SE and Co KG
Priority date: 1984-08-16
Filing date: 1985-08-14
Publication date: 1986-03-19
Also published as: DK337085A; DE3430135A1; FR2569080A1; GB2164232B; GB8520369D0; DK337085D0; DE3430135C2

Abstract

A seed drill includes a frame and sowing coulters which are disposed on said frame in a vertically pivotable manner and have a measuring device provided thereon which serves to detect the depth of soil penetration of the sowing coulters, the measuring device having at least one soil surface follower member. When viewed with respect to the direction of travel (14), the portion (13) of the follower member (9) lying on the soil (8, 16) is disposed so as to be at least approximately in alignment with the associated sowing coulter (2), and the pivotal point (12) of the follower member (9) is situated in front of the pivotal point (3) of the sowing coulter (2). <IMAGE>

Description

SPECIFICATION A seed drill The present invention relates to a seed drill including a frame and sowing coulters which are disposed on said frame in a vertically pivotable manner and have a measuring device provided thereon which serves to detect the depth of soil penetration of the soil coulters, the measuring device having at least one ground surface follower member.

A similar seed drill is known from German Patent Specification No. 3 218 839. In this seed drill, a follower member in the form of a running wheel is disposed adjacent to a sowing coulter. The pivotal joint of the follower member, whereby the follower member is pivotally connected to the frame of the seed drill, is situated behind the pivot of the sowing coulter. Measuring instruments, in the form of potentiometers, are disposed between the supporting arms which connect the sowing coulter and the follower member to the frame. By means of such measuring instruments, the depth of soil penetration of this sowing coulter is indicated on an indicating device. However, the measurement which is indicated for the depth of soil penetration of the sowing coulter is highly inaccurate. The reason for this is that the running wheel of the follower member is disposed behind the sowing coulter.Because of this arrangement, it is not possible to effect accurate measurement for the depth of soil penetration of the sowing coulter because the soil has already been moved by the sowing coulters, with the result that the running wheel travels partially over the mounds of earth which have been produced by the sowing coulters when making the sowing grooves.

Another seed drill is also known from German Patent Specification No. 3 237 538 and is provided with a measuring device for measuring the depth of soil penetration of the sowing coulters. In this seed drill also, a follower member in the form of a running wheel is disposed adjacent to a sowing coulter. Measuring instruments of a measuring device are in the form of switches and are disposed between the supporting arms for the sowing coulter and the follower member. The pivots, whereby the sowing coulter and the follower member are pivotally connected to the frame of the seed drill, are disposed adjacent one another so that the rotational axes of the sowing coulter and the follower member extend through the pivots and are in alignment with one another. The lever arm of the sowing coulter is substantially longer than the lever arm of the follower member.Because the running wheel of the follower member is disposed laterally adjacent to, and in front of, the sowing coulter, it is impossible to accurately determine the depth of soil penetration of the sowing coulter.

The present invention seeks to provide a measuring device for accurately measuring the depth of sowing coulters.

According to the present invention there is provided a seed drill including a frame and sowing coulters which are disposed on said frame in a vertically pivotable manner and have a measuring device provided thereon which serves to detect the depth of soil penetration of the sowing coulters, the measuring device having at least one ground surface follower member, characterised in that, when viewed with respect to the direction of travel, the portion of the follower member in contact with the soil is disposed so as to be at least approximately in alignment with the associated sowing coulter, and the pivot point of the follower member is situated in front of the pivotal point of the sowing counter.

As a result of these measures, and when viewed with respect to the direction of travel, the ground surface sensor or follower member follows the soil surface in the region where the associated sowing coulter makes the sowing groove in the soil, so that the measuring device accurately determines, in the required manner, the depth of soil penetration of the sowing coulter and, as a consequence thereof, the depth at which the seeds are deposited in the soil.

In order to use as simple a measuring instrument as possible and in order to be able to obtain as simple an evaluation circuit as possible for evaluating the values determined by the measuring instrument, according to the invention, the horizontal spacing between the pivotal point of the sowing coulter and the coulter tip or the point of the sowing coulter is at least approximately identical to the horizontal spacing between the pivotal point of the follower member and the point of contact of the follower member with the soil. Moreover, this arrangement permits the measuring instrument to be disposed in a very simple manner between the supporting arm and the follower member. As a consequence thereof, the change of angle is identical when the follower member or the sowing coulter is raised vertically by the same amount.This arrangement provides the sowing coulter, which dooperates with the follower member, and the follower member with identical leverage conditions.

According to a preferred aspect of the present invention, in order that the follower member operates over a region which has been cleared of relatively large clods and so that a good reference plane is created, which plane can be used as a basis for the depth of soil penetration of the sowing coulters, a clod remover is disposed in front of the follower member, and the clod remover is adapted in such a manner that the clod remover pushes at least the large clods to the side. In a preferred arrangement according to the present invention, during utilisation of the seed drill, the lower edge of the clod remover penetrates the soil.Irrespective of whether the soil surface is partially very uneven because of numerous large clods, therefore, the follower member slides over a flat soil surface which is provided by the clod remover and, on the basis of this reference flat surface, the follower member determines the depth of penetration of the sowing coulter which is disposed behind the follower member and makes a sowing furrow in the flat soil surface provided by the clod remover. In order that the clod remover does not compact the soil surface, a preferred feature of the present invention is to provide so that at least the lower front end of the clod remover travels vertically, preferably by touch, but on no account does it deviate more than 20 from the vertical in its towing position.It is vital that this fact be taken into consideration so that the depth of penetration determined for one sowing coulter can be used as a basis for the depth of penetration of the other remaining sowing coulters. If the firmness of the soil is not changed in the measuring region between the follower member and the associated sowing coulter, it may be assumed, therefore, that the depth of penetration of the other remaining sowing coulters corresponds to the depth of penetration of the sowing coulter associated with the follower member within an allowable tolerance limit.

Further details of the present invention are to be found in the other remaining sub-claims, in the description of the examples and in the drawing.

The invention will be described further, by way of example, with reference to the accompanying drawing which is a side elevational view of the normal arrangement of a measuring device on the sowing coulter of a seed drill.

In known manner, the sowing coulters (of which only one is shown) are disposed on frame 1 of the seed drill in a plurality of transverse rows arranged one behind the other. The coulters are staggered with respect to one another in adjacent arrangement and are disposed pivotable in a vertical plane by means of pivots 3. Supporting arm 4 of the sowing coulter 2 protrudes rearwardly of the pivot 3. A coulter pressure spring 5 of a central coulter pressure adjusting means 6, which is also disposed on the frame 1 of the seed drill, is mounted on a portion of the supporting arm 4 which protrudes beyond the pivot 3.

A measuring device 7 is disposed on the sowing coulter 2 and serves to determine the depth T of soil penetration of the sowing counter 2. The measuring device 7 mainly comprises a sensor or feeler or follower member 9 acting as a ground surface follower which is disposed in front of the sowing coulter 2 and is in the form of a runner. A measuring instrument 10 is disposed between the sowing coulter 2 and the member 9 and is in the form of a rotary potentiometer. The member 9 is disposed by means of pivot 12 on supporting member 11 which is welded to the frame 1 - so as to be pivotable in a vertical plane. Consequently, the pivot 12 of the member 9 is situated in front of the pivot 3 of the sowing coulter 2 with respect to the normal direction of travel 14 of the drill.When viewed with respect to the direction of travel 14, the portion 13 of each member 9 in contact with the soil 8 is disposed so as to be in alignment in front of a sowing coulter 2 associated with the member 9; that is to say, the sowing coulter 2 makes the sowing groove 15 in the soil 8 in the region where the member 9 probes the soil surface 16.

The horizontal spacing A between the pivotal point of the sowing coulter 2, which is formed by the pivot 3, and the coulter tip 17 of the sowing coulter 2 is identical to the horizontal spacing B between the pivotal point of the member 9, which is formed by the pivot 12, and the point of contact 18 of the member 9 with the soil 8. The rotary potentiometer 10 is securely screw-connected to the supporting arm 4 of the sowing coulter 2. In such an arrangement, the rotational axis 19 of the control lever 20 of the rotary potentiometer 10 is in alignment with the pivotal axis of the sowing coulter 2, which axis extends through the pivot 3, so that the rotational axis 19 of the control lever 20 of the rotary potentiometer 10 coincides with the pivotal axis of the sowing coulter 2. A lever 21 is mounted on the member 9 in the region of the pivot 12.The end of the lever 21 remote from the pivot 12 is connected, by means of ball-and-socket joints 23, to the control lever 20 via a rod 22, so that a control linkage in the form of a parallelogram is provided for the rotary potentiometer 10.

The rotary potentiometer 10 is connected to indicating member 25 and on switch box 26 via cable 24. The switch box 26 accommodates a microprocessor and a setting device for setting the central coulter pressure adjusting means 6. For this purpose, a hydraulic cylinder 27 is connected, via the pipes 28, to the setting device which is accommodated in the switch box 26. Moreover, the setting device is connected, via the pipes 29, to the hydraulic system of the tractor towing the seed drill.

A clod remover 30 is disposed on the supporting member 11 in front of the member 9. The clod remover 30 is mounted in a vertically adjustable manner by means of adjusting screw 31. The clod remover 30 is set in such a manner that it pushes the large clods aside. During utilisation of the seed drill, lower edge 32 of the clod remover penetrates some way into the soil 8 so as to positively push the large clods to the whilst at the same time, providing a flat soil surface 16 along which the member 9 can probe the soil. Lower front end 33 of the clod remover 30 extends vertically and has a light "touch". This arrangement ensures that the clod remover 30 does not in any way compact the soil surface 16.

The mode of operation of the measuring device 7 can be described as follows: Initially the clod remover 30 is set in such a manner that it pushes the large clods to the side and creates a flat soil surface 16. In addition, the indicating member 25 is calibrated or adjusted to the zero mark; that is to say, the coultertip 17 of the sowing coulter 2 and the portion 13 of the member 9 in contact with the soil surface 16 are brought to the same level and the pointer 34 of the indicating member 25 is set to "0". In practical terms, this means that, when the pointer indicates "0", the depth of soil penetration of the sowing coulter 2 is equal to "0" and the coulter tip 17 is on a level with the soil surface 16. Consequently, the pertinent depth T of the penetration of the sowing coulter 2 in the soil 8 is then indicated by means of setting pointer 34.

However, it is also conceivable that the pointer 34 of the indicating member 25 is set in such a manner that any actual deviation from the desired depth T of the penetration of the sowing coulter 2 in the soil 8 is indicated. For this purpose, the member 9 is then raised to such an extent that the vertical spacing, which corresponds to the desired penetration depth T of the sowing coulter 2, is achieved between the coulter tip 17 of the sowing coulter 2 and the portion 13 of the member 9 in contact with the soil 8. The scale of the indicating member 25 orthe pointer 34 is now set to the zero mark.

As the seed drill deposits seeds in the soil 8, the clod remover 30 pushes the large clods to the side and thereby creates the flat soil surface 16. in this region of the soil 8, the probe or follower member 9 travels over the flat soil surface 16 and thus probes the soil surface 16. The sowing coulter 2 makes the sowing groove 15 in the soil 8 behind the member 9.

The seeds are deposited in the sowing groove 15 in the soil 8.

At the same time, the rotary potentiometer 10 transmits the appropriate measured values to the indicating member 25 via the cable 24. The indicating member 25 then indicates the appropriate depth Tforthe sowing coulter2, and this is representative, therefore, for all of the sowing coulters.

If the value indicated by the indicating member 25 deviates from the desired value for the depth T, the operator may suitably alter the coulter pressure via the lever 35 of the setting device for setting the central coulter pressure adjusting means 6.

It is also possible, however, for the measurements to be fed to the microprocessor (which is accommodated in the switch box 26) from the rotary potentiometer 10 via the cable 24. The microprocessor compares the measurements with the desired depth fed into the microprocessor via keys of the switch box 26. If the values determined by the rotary potentiometer 10 deviate from the desired depth, the microprocessor automatically actuates the setting device for setting the central coulter pressure adjusting means 6 so that the tension of the coulter pressure springs 5 is changed.

The tension of the coulter pressure springs 5 is increased when the depth T of the sowing coulters 2 is too small, so that the sowing coulters 2 are pressed into the soil 8 by means of a relatively large force which is produced by the coulter pressure springs 5. The tension of the coulter pressure springs 5 is reduced when the depth T of the sowing coulters 2 is too large, so that, due to the low tension of the coulter pressure springs 5, the sowing coulters 2 are raised to some extent by the soil resistance. As a consequence thereof, the sowing coulters 2 are automatically provided with a constant depth through the soil 8, in practical terms, so that the seeds can be deposited in the soil at a uniform depth.

Claims

1. A seed drill including a frame and sowing coulters which are disposed on said frame in a vertically pivotable manner and have a measuring device provided thereon which serves to detect the depth of soil penetration of the sowing coulters, the measuring device having at least one ground surface follower member, characterised in that, when viewed with respect to the direction of travel, the portion of the follower member in contact with the soil is disposed so as to be at least approximately in alignment with the associated sowing coulter, and the pivot point of the follower member is situated in front of the pivotal point of the sowing coulter.

2. A seed drill as claimed in claim 1, in which the horizontal spacing between the pivot point of the sowing coulter and the coulter tip of the sowing coulter is at least approximately identical to the horizontal spacing between the pivot point of the feeler member and the point of contact of the feeler member with the soil.

3. A seed drill as claimed in claim 1, in which a clod remover is disposed in front of the follower member, and the clod remover is adjusted in such a manner that the clod remover pushes at least the large clods aside.

4. A seed drill as claimed in claim 3, in which during utilisation of the seed drill, the lower edge of the clod remover penetrates the soil.

5. A seed drill as claimed in claim 3, in which at least the lower front end of the clod remover travels vertically, preferably by touch, but on no account does it deviate more than 20 from the vertical when being towed.

6. A seed drill as claimed in any of claims 1 to 5, in which a measuring instrument is disposed between the follower member and the sowing coulter which is associated with the follower member.

7. A seed drill as claimed in claim 6, in which the measuring instrument is connected to an indicating member.

8. A seed drill as claimed in claim 6, in which the measuring instrument is connected to a microprocessor.

9. A seed drill as claimed in any of claims 1 to 8, in which the follower member is a sliding runner.

10. A seed drill substantially as herein described with reference to and as illustrated in the accompanying drawing.