GB2126062A

GB2126062A - Drill

Info

Publication number: GB2126062A
Application number: GB08318890A
Authority: GB
Inventors: Benno Wiemeyer
Original assignee: Amazonen Werke H Dreyer SE and Co KG
Current assignee: Amazonen Werke H Dreyer SE and Co KG
Priority date: 1982-07-16
Filing date: 1983-07-13
Publication date: 1984-03-21
Also published as: GB8318890D0; FR2530113A1; DE3226659C2; GB2126062B; DE3226659A1; FR2530113B1

Abstract

A drill including a frame and sowing coulters disposed on the frame in a vertically pivotable manner, such sowing coulters being individually connected to the frame by resilient members which act upon the sowing coulters in the direction of the soil, the tension of such resilient members being adjustable by a central adjusting means in order to achieve a uniform depth for the sowing coulters. To control the depth of the sowing coulters of drills in an automatic manner in dependence upon the soil conditions, so that a uniform depth is ensured for the sowing coulters, a measuring arrangement (25) is disposed on the drill to measure the depth (T) of the sowing coulters (9), and such measuring apparatus (25) is connected to the central adjusting means (17). <IMAGE>

Description

SPECIFICATION Drill The invention relates to a drill including a frame and sowing coulters disposed on the frame in a vertically pivotable manner and said sowing coulters being individually connected to the frame by resilient members which act upon the sowing coulters in the direction of the soil with the tension of said resilient members being variable by a central adjusting means in order to achieve a uniform depth of penetration for the sowing coulters.

A drill of this type is already described in German Gebrauchmuster (Utility Model) No. 7825061 and permits a manually operable, central adjusting means to increase or reduce the coulter pressure acting upon the sowing coulters in the direction of the soil, by varying the tension of the springs disposed on the sowing coulters from the tractor seat. This permits the coulter pressure, acting upon the sowing coulters, to be adapted to the actual soil conditions in order to ensure that the sowing coulters always travel through the soil at a uniform depth, even on soils having different or varying soil resistances.

However, this drill is very disadvantageous in that, prior to cultivating a field, the operator of the drill has to initially ascertain the various soil resistances in the whole field which is to be cultivated. The so-called "heel method" is used for this purpose; that is to say, a person walks over the field and digs the heel of his shoe into the soil at various locations in the field, thereby ascertaining the soil resistance and the necessary coulter pressure on the basis of the various imprint depths of the shoe heel. It is only possible to ascertain by this method whether more or less coulter pressure is required at any one location.

This method is extremely inaccurate, completely inadequate and very time-consuming. Thus this known, manually operable, central adjusting means for varying the coulter pressure can only achieve a uniform depth for the sowing coulters in an adequate manner.

The "Saxonia-Steckbrief Nr. 6 - Niveau- Metrik" ("Saxonia Article No. 6 - "Level Metrics") describes a measuring arrangement for measuring the depth at which the sowing coulters travel through the soil. This apparatus is provided with a measuring wheel which travels along the surface of the soil and is disposed adjacent a sowing coulter, and the difference in depth between the measuring wheel, forming the reference value, and the sowing coulter is transmitted to the indicating device. Depending on the values indicated on this indicating device, the operator of the drill then has to manually adjust the tension of the springs disposed on the sowing coulters and, as a consequence thereof, the coulter pressure acting upon the sowing coulters is varied.This apparatus is disadvantageous, firstly because the coulter pressure has to be varied manually and secondly because the coulter pressure cannot be altered rapidly enough especially when there are frequent changes in soil resistance over short distances. This very often means that the coulter pressure is only changed at a time when it is in fact no longer necessary to have such a change. As a consequence thereof, an incorrect coulter pressure is very often set or, alternately, the coulter pressure is changed at the wrong time. This causes drills which are provided with this measuring arrangement to produce a depth for the sowing coulters which is substantially less uniform than a depth produced by drills having no such measuring arrangement.

In addition, the operator has to constantly observe the indicating device during the entire drilling operation with the result that he can only inadequately fulfil other monitoring operations and continue travelling in an accurate manner.

Finally, German Offenlegungsschrift No. 2 631 104 describes a depth control means for beet harvesting machines. This depth control means is provided with a feeler device disposed adjacent a support runner or roller. Such a depth control means ensures that the depth of the digging coulter always remains constant, even on soils having different load bearing capacities, because the feeler device produces pulses via two switches, and such pulses cause the frame of the beet harvester to be raised or iowered accordingly.

The invention seeks to control the depth of the sowing coulters of drills in an automatic manner in dependence upon the soil, so that a uniform depth is ensured for the sowing coulters.

According to the present invention there is provided a drill including a frame and sowing coulters disposed on the frame in a vertically pivotable manner and said sowing coulters being individually connected to the frame by resilient members which act upon the sowing coulters in the direction of the soil with the tension of said resilient members being variable by a central adjusting means in order to achieve a uniform depth of penetration for the sowing coulters, characterised in that a measuring apparatus is mounted on the drill to measure the depth (T) of the sowing coulters, and such measuring apparatus is coupled to the central adjusting means.As a result of these measures, a constant depth is automatically ensured for the sowing coulters, even when the nature of the soil varies considerably and even when soil resistances are constantly changing, without the operator of the drill having to control the operation in any way.

Due to this uniform depth of the sowing coulters, a predetermined depth for depositing seeds is maintained at all times, so that the seeds are given optimum germination and growth conditions which are pre-requisites for obtaining optimum yields.

The invention additionally provides that the measuring arrangement transmits pulses to the central adjusting means and that the tension of the resilient members is variable, by means of such pulses, via the central adjusting means. Due to these measures, the tension of the resilient members and also, as a consequence thereof, the coulter pressure are constantly adapted to the soil conditions actually prevailing at any time. In such a case, the invention should also include the feature that the measuring arrangement is provided with appropriately formed electrical or electronic regulators for suitably controlling the central adjusting means. It is thereby possible to set any desired depth for the sowing coulters via such regulators.

In a preferred arrangement, the invention provides that the measuring arrangement has a spring-ioaded, narrow disc and a wider roller which travels along the soil surface, the disc and the roller are each vertically displaceably connected to the frame of the drill via respective support members, and an arrangement which measures the difference between the penetration depths of roller and disc, or respectively measures the penetration depth of the disc, is connected to the two support members. These measures permit the measuring arrangement to be in the form of a separate component which may be attached to any machine, thereby permitting the drill to be very easily fitted with such an arrangement.

In another embodiment of the invention the measuring arrangement co-operates with at least one sowing coulter and one sensor which is disposed in the region of such sowing coulter. A very simple measuring arrangement is thereby achieved, which co-operates with at least one sowing coulter wherein at least one sowing coulter is utilised to measure the depth of the sowing coulters.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a side elevational view of a drill; Fig. 2 is an enlarged, fragmentary side elevational view of the apparatus of Fig. 1 illustrating the measuring arrangement; Fig. 3 is a schematic side elevational view of an alternative embodiment of the measuring arrangement according to the invention; and Fig. 4 is a plan view of the measuring arrangement as shown in Fig. 3.

A drill is provided with the frame 1 and a storage container 2 and, in its operating position, is supported on the soil 4 by running wheels 3. In this operating position, the drill is connected to the three-point power lift of a tractor (not shown) via coupling members 5 and is towed over the field to be cultivated in the travel direction indicated by arrow 6. During this operation, seeds from the storage container 2 are deposited in the soil 4 in adjustable quantities via metering device 7, seed conducting pipes 8 which are connected to such metering device 7, and sowing coulters 9, only one of which is illustrated in the drawing.

Each sowing coulter 9 is mounted on the frame 1 in a vertically pivotable manner by means of a coulter support lever 10 and is connected to a lever 12 by a resilient member 11. All of the levers 12 are welded to the transverse pipe or tube 1 3 rotatably mounted on the frame 1. In order to permit the initial tension of each individt resilient member 11 to vary automatically, the end of each such resilient member, at the coulter end, is disposed on the apertured bar 14, and one of the bores 1 5 of the apertured bar 14 is selected to permit the bar 14 to be suspended on a pin 1 6 welded to the coulter support lever 10.

A central adjusting means 1 7 is disposed at the front of the drill and permits the initial tension of all of the resilient members 11 connected to the sowing coulters 9, to be jointly altered. The adjusting means 1 7 is provided with a support 1 8 which is rigidly mounted on the frame 1, and a scale is disposed laterally of the support 18, such a scale indicating the pressures at which the sowing coulters 10 may be additionally loaded via the resilient members 11. In addition, a doubleacting cylinder 20 is pivotally mounted on the support 1 8 and acts as an actuating device 1 9 for actuating the central adjusting means 17 and a piston rod 21 of hydraulic cylinder 20 engages on a lifting arm 22 which is welded to the transverse pipe 1 3.Hydraulic hoses 23 of the hydraulic cylinder 20 are connected to a control device 24 which actuates the hydraulic cylinder 20 of the central adjusting means 1 7. The control device 24 is additionally connected to the hydraulic system of the tractor towing the drill.

In addition, a measuring apparatus 25 for measuring the depth T of the sowing coulters 9 is disposed on the drill. Such measuring arrangement 25 co-operates with a sowing coulter 9 and a sensor 27 which is in the form of a roller 26 and is disposed in the region of this sowing coulter 9. The roller 26 is pivotally mounted on the frame 1 of the drill in a vertically displaceable manner by means of a support arm 28 and travels along the soil surface 4. The measuring apparatus 25 is provided with two switches 29 and 30 which are adjustably mounted in slots on a plate 31 disposed on the support arm 28 of the roller 26, the switches 29 and 30 cooperating with the coulter support lever 10 of this sowing coulter 9. These two switches 29 and 30 are connected to the control device 24 via leads or cables 32, so that the measuring apparatus 25 is connected to the central adjusting means 17. The maximum depth T of the sowing coulters 9 is limited by the lower switch 29, when the coulter support lever 10 abuts the pulse or signal generator 33. The switch 29 hereby issues a signal or pulse which is transmitted to the control device 24 via the cables 32. Due to this pulse, the control device is caused to control the hydraulic cylinder 20 so that the tension of the resilient members 11 is reduced, and consequently so is the coulter pressure. The depth T of the sowing coulters 9 is reduced and is re-set to the desired value.

An upper switch 30 ensures that the minimum depth T of the sowing coulters 9 is at least maintained. If the soil resistances increase, the sowing coulters 9 attempt to come out of the soil 4. In this case, the coulter support levers 10 for supporting the sowing coulters 9 are then caused to abut pulse generator 33 cf the upper switch 30 and, as a consequence thereof, the levers 10 release a signal or pulse which is transmitted to the control device 24 via the cables 32. Due to this pulse, the control device 24 controls the hydraulic cylinder 20 in such a manner that the tension of the resilient members 11 is increased, and consequently so is the coulter pressure. The sowing coulters 9 are hereby pressed again more deeply into the soil so that, in turn, the desired depth T for the sowing coulters 9 is maintained.

In addition, stop members 34 are disposed on the switches 29 and 30 and limit the pivotal movement of the sowing coulter 9, which serves to measure the depth T, within the measuring range of the measuring arrangement. Such stop members 34 also prevent the switches 29 and 30 from becoming damaged, and in particular they also prevent the respective pulse generators 33 from becoming damaged.

At the beginning of a drilling operation, the switches 29 and 30 are set so that the lower switch 29 limits the desired, maximum depth T and the upper switch 30 limits the desired, minimum depth T and, as a consequence thereof, the switch 29 or 30, respectively, can transmit appropriate pulses to the control apparatus 24 of the measuring arrangement 25. The depth T and the difference between the maximum depth and the minimum depth are adapted to the actual condition of the soil and the seeds to be sown.

An alternative measuring apparatus for measuring the depth T of the sowing coulters is illustrated in Figs. 3 and 4. This measuring apparatus 35 is provided with a spring-loaded disc 36 and a wider roller 37 which travels along the soil surface 4 and the apparatus is integrated to form a compact unit and is attached to the frame 1 of the drill as an additional component.

The roller 37 and the disc 36 are each pivotally mounted, in a vertically displaceable manner, on a universal joint 39 via respective support members 38, such a universal joint 39 being rotatably disposed about a vertical axis. This universal joint 39 is flange-mounted on the frame 1 by means of U-bolts 40.

An arrangement 41, which measures the difference between the penetration depths A of roller 37 and disc 36, is connected to the two support members 38 for supporting the roller 37 and the disc 36. This arrangement 41 is in the form of a potentiometer 42 which is screwconnected to the support member 38 for supporting the disc 36, while an adjusting lever 43 for adjusting the potentiometer 42 is connected to the support member 38 for supporting the roller 37 via the intermediate lever 44. The potentiometer 42 is-connected to an electrical or electronic regulator 46 via the cables 45.Because the width of the roller 37 differs from that of the disc 36, the degree of resistance put up by the roller 37 and the disc 36 to the soil resistance varies, so that the disc 36 always penetrates more deeply into the soil 4 than the roller 37; that is to say the difference between the soil penetration depths of the roller 37 and the disc 36 is always proportional to the soil resistance. If there is little soil resistance, the difference between the penetration depths is large, but if the soil resistance is high, the difference between the penetration depths is small.

The potentiometer 42 reflects or transmits these differences between the penetration depths, and such differences are transmitted to the regulator 46 in the form of changes in electrical voltage. Due to these changes in voltage which are measure by the potentiometer 42 and are proportional to the changes in soil resistance, the regulator 46 transmits pulses to the central adjusting means 48 via the leads 47. The central adjusting means 48 is provided with an electric servomotor 49 which permits the tension of the resilient members 11, connected to the sowing coulters 9, to be changed via the lever 50. In addition, a second potentiometer 51 is connected to lever 50 and transmits to the regulator 46 the position of the lever 50 and hence, indirectly, the tension of the resilient members. The regulator 46 permits the penetration depth T of the sowing coulters in the soil 4 to be predetermined and/or adjusted. Thus, the measuring arrangement 35 which, as described above, is connected to the central adjusting means, permits the coulter pressure to be automatically adapted to the actual soil resistance, so that a uniform depth T is always achieved for the sowing coulters 9.

Finally, an indicating device 52 for indicating the depth T of the sowing coulters 9 is connected to the regulator 46 for regulating the measuring apparatus 35.

The invention is not only limited to these embodiments which are described here, but individual components of the measuring apparatus in the two embodiments may also be interchanged.

Claims

1. A drill including a frame and sowing coulters disposed on the frame in a vertically pivotable manner and said sowing coulters being individually connected to the frame by resilient members which act upon the sowing coulters in the direction of the soil with the tension of said resilient members being variable by a central adjusting means in order to achieve a uniform depth of penetration for the sowing coulters, characterised in that a measuring apparatus (25, 35) is mounted on the drill to measure the depth (T) of the sowing coulters (9), and such measuring apparatus (25, 35) is coupled to the central adjusting means (17, 48).

2. A drill as claimed in claim 1, in which the measuring apparatus (25, 35) transmits signals to the central adjusting means (17, 48), and the tension of the resilient members (11) is variable, by means of these pulses, via the central adjusting means (17, 48).

3. A drill as claimed in claim 1 or 2, in which the measuring apparatus (35) is provided with a spring-loaded, narrow disc (36) and a wider roller (37) which travels along the soil surface (4), and the disc (36) and the roller (37) are each vertically displaceably connected to the frame (1) of the drill via respective support members (38), and in which an arrangement (41) which measures the difference between the penetration depths (A) of roller (37) and disc (36), or respectively measures the penetration depth of the disc (36), is connected to the two support members (38).

4. A drill as claimed in claim 1 or 3, in which a potentiometer (42) is mounted on one of the support members (38), the other support member (38) is connected to the adjusting lever (43) of a potentiometer (42) which potentiometer (42) is connected to an electrical regulator (46), and such regulator (46) transmits appropriate pulses to the central adjusting means (48).

5. A drill as claimed in claims 1 and 3, in which the penetration depth (T) of the sowing coulters (9) in the soil (4) is adjustable by means of the regulator (46).

6. A drill as claimed in claim 1 or 2, in which the measuring arrangement (25) co-operates with at least one sowing coulter (9) and one sensor (27) which is disposed in the region of such sowing coulter (9).

7. A drill as claimed in claims 1 and 6, in which the measuring apparatus (25) is provided with two switches (29, 30), one of the switches (29) releases a signal when the maximum permitted depth is reached, and the other switch (30) releases a signal when the minimum permitted depth is reached, and these signals are transmitted to the adjusting means (17).

8. A drill as claimed in claim 7, in which the switches (29, 30) are disposed on the support arm (28) of the sensor (27), and the coulter support lever (10) for supporting the sowing coulter (9) cooperates with the switches (29, 30).

9. A drill as claimed in claims 1 and 6, in which stop members (34) limit the pivotal movement of the sowing coulter (9), which serves to measure the depth (T), within the measuring range of the measuring apparatus.

10. A drill as claimed in claim 6, in which the measuring apparatus (35) is provided with a potentiometer (42), which potentiometer (42) is connected to the sowing coulter (9), serving to measure the depth (T), and to the sensor (27), the potentiometer (42) co-operates with a regulator (46), and such regulator (46) transmits signals to the adjusting means.

11. A drill as claimed in claim 1,2,3 or 6, in which the measuring apparatus (35) is connected to an indicating device (52) for indicating the depth (T) of the sowing coulters (9).

12. A drill as claimed in claim 6, in which the sensor (27) is in the form of a runner.

13. A drill as claimed in claim 6, in which the sensor (27) is in the form of a roller (26) or running wheel.

14. A drill substantially as herein described with reference to and as illustrated in the accompanying drawings.