GB2144012A

GB2144012A - A drill

Info

Publication number: GB2144012A
Application number: GB08415113A
Authority: GB
Inventors: Franz Grosse-Scharmann; Rudolf Gehrke
Original assignee: Amazonen Werke H Dreyer SE and Co KG
Current assignee: Amazonen Werke H Dreyer SE and Co KG
Priority date: 1983-06-16
Filing date: 1984-06-13
Publication date: 1985-02-27
Also published as: GB8415113D0; DK292184D0; DE3321816A1; GB2144012B; NL8401808A; AT391970B; FR2547973A1; ES8503469A1; DK292184A; DE3321816C2; ATA196084A; ES533469A0

Abstract

A drill including a frame (4) and sowing coulters (1) which are disposed in a vertically adjustable manner thereon and which are individually connected to the frame (4) through the intermediary of resilient members (5) which act on the sowing coulters (1) in the direction of the ground (31) and have a tension which is adjustable by means of a central setting device (8) for the purpose of achieving a uniform depth (T) for the sowing coulters (1), a measuring means being disposed on the drill to measure the depth of the sowing coulters and being connected to the central setting device, wherein, in order to simplify and improve the measuring means and to utilise hydraulic control means which are available for conventional drills, the measuring means is hydraulic, has at least one hydraulic control valve (17) and directly controls the central setting device (8); a hydraulic control valve (17) being disposed between a sensor (11) and one sowing coulter (1). <IMAGE>

Description

SPECIFICATION A drill Our prior U.K. Patent Application No.

8318890 published under number 2126062 relates to a drill including a frame and sowing coulters which are disposed in a vertically adjustable manner thereon and which are individually connected to the frame through the intermediary of resilient members which act on the sowing coulters in the direction of the ground and have a tension which is adjustable by means of a central adjusting means or setting device for the purpose of achieving a uniform depth for the sowing coulters, and wherein a measuring means is disposed on the drill to measure the depth of the sowing coulters and being connected to the central setting device.

The present invention seeks to simplify the measuring means of the earlier application and to utilise the hydraulic control means which are available for conventional drills.

This object is achieved in the present invention by the fact that the measuring means is hydraulic, has at least one hydraulic control valve and directly controls the central setting device, the hydraulic control device being disposed between the sensor and one sowing coulter.

Thus, according to the present invention there is provided a drill including a frame and sowing coulters which are disposed in a vertically adjustable manner thereon and which are individually connected to the frame through the intermediary of resilient members which act on the sowing coulters to urge such in the direction of the ground and have a tension which is adjustable by means of a central setting device for the purpose of achieving a uniform depth (T) of penetration of the sowing coulters, a measuring means being disposed on the drill to measure the depth of the sowing coulters and being connected to the central setting device, characterised in that the measuring means is hydraulic and has at least one hydraulic control valve and directly controls the central setting device; the hydraulic control valve being disposed between a sensor and one sowing coulter.

These measures permit the coulter pressure to be regulated in a very simple manner using very simple and robust component parts -such being of great significance in agricultural usage. It is also possible to attach this hydraulic measuring means as an adaption to drills already on the market.

The invention also provides in a preferred embodiment that a pressure line, a return line and a control line - connected to the central setting device - are connected to the hydraulic control valve; a return valve is located in the pressure line which leads to the control valve; and a hydrostore or hydraulic reservoir is disposed in the pressure line between the return valve and the control valve. This permits the hydraulic measuring means to be simplified even further, since there is always a constant and/or adequate pressure in the control system.

In order to permit the pressure in the control system to be always reliably maintained without incurring additional expenditure, the pressure line upstream of the return valve is connected to at least one pressure line of an attachment accessory which is hydraulically operated periodically.

Further details of the invention can be found in the other remaining sub-claims, the description of the embodiments and the drawing.

The invention will be described further, by way of example, with reference to the accompanying schematic drawing which is an elevation of the hydraulic means for regulating the coulter pressure associated with a sowing coulter of a drill.

In a drill (not shown overall) and by means of coulter retaining levers 2 and through the intermediary of pivot joints 3, sowing coulters 1 are disposed in a vertically pivotable manner on a frame 4 of the drill which is of known type and therefore not shown in more detail. Each of the sowing coulters 1 is connected to a lever 6 through the intermediary of a tension spring 5. All of the levers 6 are welded to a transverse pipe or tube 7 which is pivotally mounted on the frame 4. The tension of the tension spring 5 can be adjusted by a central adjusting or setting device 8. The central setting device 8 primarily comprises lever 9, which is welded to the transverse tube 7, and a hydraulic cylinder 10, which is disposed between the lever 9 and the frame 4 of the drill.

In addition to supporting a sowing coulter 1, the frame 4 in the region of axle or pivot joint 3 also supports a feeler member or sensor 11 by means of the pivot joint 12.

When viewed in a line with the pivot joint 3 of the sowing coulter 1, the pivot joint 1 2 extends transversely to the direction of travel 1 3 of the drill. A clod remover 14 is disposed on the frame 4 of the drill upstream of the sensor 11 with respect to the normal direction of movement of the drill. The clod remover 14 is provided with the pivot joint 1 5 so that the clod remover 14 can be deflected about said pivot joint 1 5 in an opposite direction to the direction of travel 1 3 in opposition to the force of return or tension spring 1 6 when obstacles are encountered.

Together with a hydraulic control valve 1 7 which is disposed on the coulter retaining lever 2, the sensor 11 forms the measuring means for measuring and setting the depth T of the sowing coulters 1. The control valve 1 7 includes control lever 1 8 which is connected to the sensor 11 through the intermediary of the rod 19. The rod 19 comprises two telescoping portions securable together by screw means so that different depths T of the sowing coulters 1 can be set for different seed deposit depths depending on the conditions actually prevailing.

A pressure line 20, return line 21 and control line 22 (connected to the central setting device 8) are connected to the hydraulic control valve 1 7. The pressure line 20 is connectable (shown connected) to the hydraulic connection 23 of a tractor which is to pull the drill.The non-return valve 24 is disposed in the pressure line 20 leading to the control valve 1 7. A hydraulic reservoir 25 is disposed in the pressure line 20 between the valve 24 and the control valve 1 7. Upstream of the non-return valve 24, the pressure line 20 is connected to the pressure line 26, which leads to the hydraulic cylinder 27 of the automatic switch for track markers (not shown), and to a pressure line 28, which communicates with the hydraulic cylinder 29 for the automatic switch of a tram line circuit arrangement (for trace drilling) (not shown).

These hydraulically operated accessories - the automatic switch for the track markers and the automatic switch for the tramline circuit - are actuated whenever the drill turns at the end of a field, so that these accessories are periodically switched. The hydraulic cylinders 27 and 29 are single-acting hydraulic cylinders, and the counteracting force is produced by a spring. Because the pressure lines 26 and 28 are connected to the pressure line 20, the pressure lines 20, 26 and 28 are subjected to pressure upon actuation of the hydraulic valve at the tractor end, so that the hydraulic cylinders 27 and 29 switch the automatic switches for track markers and/or tramline circuit. This also causes the hydraulic reservoir 25 to be filled once more.After the automatic switches have been connected, the hydraulic valve at the tractor end is set to "lower" once more, so that the pressure line 20' between the return valve 24 and the hydraulic connection with the tractor serves as a return line for the return line 21.

The control line 22' leads to the hydraulic cylinder 30 of the means for adjusting the pressure of the seed covering device or raking comb (saatstriegel) and is connected to the control line 22. This results in the pressure of the seed raking comb also being adjusted simultaneously with the change in the pressure of the coulter.

The hydraulic measuring means, with pressure adjustment for the coulter pressure and raking comb pressure, operates as follows: By setting the hydraulic valve at the tractor end to "lift", the automatic switches (circuit brakers) are connected and at the same time the hydraulic reservoir 25 is topped-up to maximum pressure, so that the measuring means and the central setting device can operate.

Through the intermediary of the telescoping portions, the sensor 11 is then set at the "0position" of the control lever 1 8 with respect to the sowing coulter 1, so that a spacing corresponding to the depth T of the sowing coulter 1 - is produced between the underside of the sensor 11 and the underside of the sowing coulter 1.

While the drill is being used, the sensor 11 scans (follows) the ground surface 31 - devoid of large clods because of the clod remover 14 - in the region of the sensor 11. The initial tension of the tension springs 5 for the individual sowing coulters 1 is so selected that the desired depth T is achieved for the largest part of the field on which the drill is being used, depending on the firmness of the ground surface 31.

Where the ground surface 31 of the field is not very firm, the sowing coulter 1 will sink downwardly, so that the depth T of the sowing coulter 1 becomes greater. The sinking of the sowing coulter 1 produces a relative movement between the sowing coulter 1 and the sensor 11, so that the control lever 1 8 of the control valve 1 7 is moved. This causes the control line 22 in the control valve 1 7 to open and, since oil flows from the hydraulic cylinder 10 into the return line 21 through the intermediary of the control line 22, the coulter pressure acting on the sowing coulters 1 is reduced and because of the reduced coulter pressure, the sowing coulters 1 are pressed so far upwardly by the ground resistance until the set depth T is reached.When the set depth T has been reached, the control lever 1 8 is rotated once more to such an extent that the control line 22 in the control valve 1 7 is closed once more.

In regions of the field where the ground surface is firmer, the position of adjustment of sowing coulter 1 is raised because of the greater ground resistance, so that the depth T of the sowing coulter 1 becomes smaller. The raising of the sowing coulter 1 produces a relative movement between the sowing coulter 1 and the sensor 11, so that the control lever 18 of the control valve 1 7 is moved. This causes the control line 22 in the control valve 1 7 to be connected to the pressure line 20. In turn, hydraulic oil then flows into the control line 22, so that the pressure in the control line 22 is increased and the hydraulic cylinder 10 becomes slightly extended. Thus, the coulter pressure acting on the sowing coulters 1 is increased. Because of the increased coulter pressure, the sowing coulters 1 are pressed sufficiently into the ground and in opposition to the ground resistance, until the set depth T is reached. When the set depth T has been reached, the control lever 1 8 has been rotated once more to such an extent that the control line 22 in the control valve 1 7 is closed once more.

In order to ensure that the measuring means operates in as uniform a manner as possible, means for absorbing impacts and vibrations or oscillations may be disposed on the sensor 11 and the sowing coulter 1.

The control valve 1 7 has a certain amount of inertia, with the result that, when the sowing coulter 1 encounters a stone, the control valve 1 7 does not immediately respond. Because this control valve 1 7 is provided with a certain amount of inertia, the depth of the sowing coulters 1 is regulated in a smooth manner.

Claims

1. A drill including a frame (4) and sowing coulters (1) which are disposed in a vertically adjustable manner thereon and which are individually connected to the frame (4) through the intermediary of resilient members (5) which act on the sowing coulters (1) to urge such in the direction of the ground (31) and have a tension which is adjustable by means of a central setting device (8) for the purpose of achieving a uniform depth (T) of penetration of the sowing coulters (1), a measuring means being disposed on the drill to measure the depth of the sowing coulters (1) and being connected to the central setting device (8), characterised in that the measuring means is hydraulic and has at least one hydraulic control valve (17) and directly controls the central setting device (8); the hydraulic control valve (17) being disposed between a sensor (11) and one sowing coulter (1).

2. A drill as claimed in claim 1, in which a pressure line (20), a return line (21) and a control line (22) are connected to the central setting device (8) and are connected to the hydraulic control valve (17); a non-return valve (24) is located in the pressure line (20) which leads to the control valve (17); and a hydraulic reservoir (25) is disposed in the pressure line (20) between the return valve (24) and the control valve (17).

3. A drill as claimed in claim 2, in which the pressure line (20) upstream of the nonreturn valve (24) is connected to at least one pressure line (26, 28) of an attachment member or accessory (27,29) which is hydraulically periodically operate.

4. A drill as claimed in claim 1, in which a seed raking comb (30) - disposed behind the sowing coulters (1) - is additionally adjustable by means of the control valve (17).

5. A drill as claimed in claim 1, in which the sensor (11) is adjustable.

6. A drill as claimed in claim 1, in which a clod remover (14) is disposed upstream of or in front of the sensor (11).

7. A drill as claimed in claim 6 in which the clod remover (14) is disposed in such a manner as to be deflectable in the opposite direction to the direction of travel (13).

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