GB2127263A - Agricultural implements - Google Patents

Abstract

An agricultural machine comprises a chassis arranged to be supported from the ground and drawn across the ground by means of a tractor vehicle and a number of ground treating implements such as a seed drill (40) movably mounted on the chassis with means (71, 72) operative between the chassis and the implements to urge them towards or into the ground in which the implements are mounted on the chassis so as to extend forwardly from it in use, the arrangement being such that the load imposed on the implement by forward movement over or in the ground reacts to urge the implement onto or into the ground. <IMAGE>

Description

SPECIFICATION Improvements in or relating to agricultural implements This invention relates to agricultural implements of the kind which may be towed across the ground by a tractor vehicle to work upon the soil typically for the purposes of preparing or sowing seed into it. The invention finds particular application in seed drills, and this specification is directed to such machines.

However, it should be understood that in many of its aspects the invention has wider application, to other agricultural ground treating implements.

In many agricultural implements used for treating the ground a chassis is provided which is supported from the ground by wheels or other suitable means and arranged to be drawn across the ground by a tractor vehicle. Ground treating implements are mounted on the chassis to engage and treat the ground as the chassis is drawn across the ground. In many such machines, particularly where the implements are required to penetrate the ground, it has been necessary to provide considerable weight acting on the chassis to force the implements into the ground. Many such machines have provision for large removable weights for the purposes of loading the machine. Such an arrangement is inconvenient in practice and results in additional costs in manufacture and use of the machines.

It is an object of the present invention to provide an improved arrangement which alleviates these problems. It is a further object to provide an arrangement in which a series of such implements may be caused to engage the ground with substantially equal face despite uneveness of the ground, and to penetrate the ground equally to a controlled depth.

Accordingly, the present invention provides an agricultural machine comprising a chassis arranged to be supported from the ground and drawn across the ground by means of a tractor vehicle and a number of ground treating implements mobably mounted on the chassis with means operative between the chassis and the implements to urge them towards or into the ground in which the implements are mounted on the chassis so as to extend forwardly from it in use, the arrangement being such that the load imposed on the implement by forward movement over or in the ground reacts to urge the implement onto or into the ground.

Preferably the implements are carried on an arm pivotally mounted on the chassis about an axis which is horizontal and transverse to the direction of motion, such arm extending forwards from the chassis in use.

Preferably each such implement is provided with a respective arm.

Preferably each such implement is provided with a respective hydraulic ram device operative between the chassis and the implement to urge it towards the ground.

Preferably means is provided to control the pressure of hydraulic fluid supplied to such hydraulic ram device so that the force with which the implement engages the ground may be controlled.

Preferably the hydraulic supply to such hydraulic device includes a gas fulled accumulator device arranged to maintain substantially constant hydraulic pressure over the range of movement of the implement relative to the chassis when the implement is engaging the ground.

Preferably the mounting of the implements on the chassis is such that a constant pressure in the hydraulic system urging the implements towards the ground results in a constant force of engagement of the implements with the ground.

Preferably the depth of penetration of the implements is controllable by means of a ground engaging wheel system arranged to control thepenetra- tion of the implement. Preferably an overall adjustment is provided effective between the ground engaging wheel system and all the implements.

Such wheel system may preferably comprise a wheel for each such implement arranged to follow behind the implement in use and to move with the implement relative to the chassis as one unit.

Preferably individual adjustment between the ground engaging wheel and the implement is provided.

Preferably such ground engaging implements are seed drilling coulters.

Preferably the coulters are each mounted on their respective arms so as to be pivotally adjustable about a generally vertical axis, thus to adjust the width of cut which they make in the ground.

The hydraulic rams arranged to urge the implements towards the ground may be double acting hydraulic rams to raise or lower the implements relative to the chassis, or may be a single acting ram arranged to urge the implements towards the ground with spring means for raising the implements relative to the ground.

Preferably the chassis comprises a single transverse cross beam having a supporting wheel arranged by the end.

Preferably the chassis is provided with a pair of retractable wheels at one side so that the whole implement may be towed sideways for transportation between places where it is used. Preferably a tow bar is provided at the other side of the chassis for such towing, the tow bar being arranged to telescope into the main chassis when not in use.

In one preferred arrangement in which the ground engaging implements are seed drilling coulters, and the coulters are carried on an arm pivotally mounted on the chassis, seed feed tubes are provided passing through such arm immediately behind the axis of the coulter to enable seed to be deposited in the ground beside the rear part of the coulter disc.

The invention also extends to a hydraulic control circuit for controlling the operation of the ground engaging implements.

In order to promote a fuller understanding of the above and other aspects of the present invention, an embodiment will now be described by way of example with reference to the accompanying drawings, in which; Figure 1 shows a schematic perspective view of a seed drill embodying various aspects of the inven tion; Figure 2 shows a view of the seed drill of Figure 1 from the front; Figure 3 shows an end view of the seed drill of Figure 1; Figure 4 shows an outline side view of the drill of Figure 1 in its arrangement for towing between places of use; Figure 5 shows in schematic cross section the seed drill of Figure 1 embodying a double acting hydraulic system; Figure 6 shows part view similar to Figure 5 of a seed drill embodying a single acting hydraulic system; Figure 7 shows a side view of a coulter and arm of the seed drill of Figure 1;; Figure 8 shows a front view of the coulter of Figure 7; Figure 9 shows a plan view of the coulter of Figure 7; Figure 10 shows a schematic hydraulic circuit for controlling a single acting hydraulic system; and Figure ii shows a similar circuit for a double acting hydraulic system.

This embodiment of the invention comprises a seed drill for the direct drilling of seed into the ground, alone or together with a fertiliser for the seed. The seed drill comprises a transverse chassis member 20 having a side wheel 21 arranged at each end of the chassis 20 to support it so that it may be towed across the ground by a tractor vehicle (not shown) by means of a tow bar 22. The tow bar is pivotally mounted on the chassis about a transverse axis 23 and an adjustable link 24 is provided between a bracket 25 on the chassis and the tow bar to adjust the angle of the tow bar to the machine as a whole.

As can be seen from Figures 1, 2 and 3 the seed drill is very much wider than the transverse direction than its length in the fore and aft direction, and because of this it is more convenient to tow it from place to place sideways. For this purpose the chassis is provided with a pair of retractable wheels indicated generally at 30 and a second tow bar 31 which the other end may be lifted and twoed by a tractor vehicle. The second tow bar 31 is retractable within the chassis as indicated schematically in Figure 1.A series of seed drill coulters indicated generally at 40 are carried on the chassis extending forwards from the main chassis and the line of the axles of the wheels 21.

Figure 5 shows a schematic cross section of the seed drill of Figures 1,2 and 3. The main chassis 20 is in the form of a rectangular cross section steel tube 50 having an axle for a ground wheel 21 at each end indicated at 51. Extending forwards from the main tube 50 is a fabricated structure 52 which carries the tow bar 22 pivotally connected at the axis 23.

A pair of hoppers 53 and 54 are mounted on the top of the chassis 20 to carry a stock of seed and/or fertiliser. The hoppers are provided with feed mechanisms 55 and 56 of known design per se arranged to feed material from the respective hoppers to feed tubes 57 and 58 which are provided for each of the coulters 40. When the implement is towed across the ground in use, the feed mechanisms 55 and 56 are driven in known manner per se to feed material from the hoppers to the respective feed tubes and thus to the coulters.

Each coulter 40 comprises a generally part spherical dished wheel 60 which is rotatably mounted about an axis 61 on a coulter arm 62 which in turn is pivotally mounted on the main chassis 20 about an axis 63. The disc 60 is of known design per se and is arranged to engage and cut into the ground indicated at 64 to form a slit into which seed and/or fertiliser is fed simultaneously from outlet nozzles 65 and 66 at the bottom of feed tubes 57 and 58.

Figures 7,8 and 9 shown in more detail the arrangement of the coulter disc 60 on the arm 62.

Disc 60 is mounted on a shaft carried in a bearing block 67 which is pivotally mounted about a generally vertical axis 68 on the arm 62. The bearing block 67 may be locked in a chosen angular adjustment relative to the arm 62 by means of a clamping bolt 69. Thus, as can best be seen in Figure 9, the angle of the plane of the coulter disc 60 may be adjusted relative to the line of the arm 62 and thus the fore and aft direction of the implement. The adjustment provided typically allows for this angle to be between 0" and 7 . By this means the width of the slot cut in the ground by the coulter may be adjusted to suit the various types of soil which may be treated to provide an optimum groove for seed and fertiliserto be fed into and closed over after passage of the implement.A chute 70 is mounted on the bottom of the arm 62 to conduct seed and/or fertiliser from the outlets 65 and 66 to the lower part of the surface of the coulter disc 60. The plane of the coulter disc is preferably inclined to the vertical as best seen in Figure 8, preferably by some 3 .

Referring again to Figure 5, it can be seen that loading means is provided to be operative between the main cross beam 50 of the chassis 20 each coulter arm 62. In Figure 5, this loading means takes the form of a double acting hydraulic piston and cylinder device 71 pivotally connected at an axis 72 to the coulter arm 62. By operation of the cylinder 71, the coulter disc can be urges into engagement with the ground to operate thereon to cut a seed groove.

In the alternative by opposite operation of the cylinder 71, the coulter arm can be pivoted to lift the coulter disc clear of the ground.

With this arrangement it can be seen that control of the hydraulic pressure in the cylinder 71 can control the force with which the coulter arm 62 and thus the coulter disc is forced towards the ground. A hydraulic circuit, to be described below, is provided for this purpose and it is arranged that the pressure in the cylinder 71 is maintained substantially constant through movements of the coulter arm relative to the beam as the implement traverses the ground thus maintaining a constant force urging the coulter into the ground. Since a separate cylinder 71 is provided for each coulter arm and coulter disc, it can be seen that by this means each coulter disc is urged towards the ground with a similar force irrespective of any unevenness of the ground over which the implement is operating. The geometry of the mounting of the cylinder 71 relative to the arm 62 is arranged to optimise the maintenance of a constant force during movement of the coulter arm 62 relative to the chassis beam 50.

It will be noted that the coulter arms extend forwards from the chassis beam 50 and thus the forces acting on the coulter arm as a result of resistance to forward movement of the coulter discs through the soil tend to pivot the coulter arm 62 in a direction to increase the load on the coulter arm. By this means, a penetrating force is achieved without resorting to a heavy chassis or the use of weights on the chassis to ensure penetration.

In order to control the depth of penetration of the coulter disc 60, a depth control wheel 80 is provided on each coulter arm 62. The wheel 80 trails behind the coulder disc 60 and is carried, in a bearing arrangement, on a trailing link 81 pivotally mounted at an axis 82 on the coulter arm 62. An adjustable length pivotal link 83 is arranged between the trailing end of the arm 81 and an arm 84, which is carried on a transverse shaft 85, pivotally mounted about an axis 86 on the chassis beam 50. Thus a trianble is formed by the coulter 62 and trailing link 81 and the link 83. The geometry of this triangle can be varied by pivoting the arm 84 to raise or lower the ground wheel 80 relative to the coulter disc 60.This movement is achieved by an arm 87 connected to the transverse shaft 85 and an adjustable link 88 extending between the arm 87 and a bracket 89 on the chassis beam 50. Thus operation of the adjustment mean 88 will adjust the depth penetration of all the coulter discs simultaneously. In order to allow for their respective ground wheel 80 to accommodate for manufacturing errors and replacement of individual assemblies, the link 83 may be adjusted in length individually.

The wheels 80 also serve to smooth over and close the slit opened up by the coulter after the seed and/or fertiliser has been inserted.

Figure 6 shows a similar view to that of Figure 5 of a coulter arm assembly in which the double acting cylinder 71 is replaced by a single acting cylinder 90.

The cylinder 90 acts to urge the coulter disc 60 into the ground, and a coil spring 91 wrapped around the cylinder 90 is used to lift the coulter arm on release of hydraulic pressure. In other respects the arrangement with Figure 6 is identical to that of Figure 5 and similar parts have been given the same reference numbers.

Figure 10 shows a schematic hydraulic circuit for use with the single acting arrangement of Figure 6. A coupling 100 for connecting the circuit to the hydraulic supply of a tractor vehicle is indicated at the top right hand corner of thw Figure. This supply is connected by mens of a pressure control valve 101 to a manifold 102 to take up hydraulic fluid from the cylinders 90 as the various coulter arms are deflected due to unevennessof the ground, thus to maintain a constant pressure in the cylinders 90. The actual value of the pressure may be indicated by a pressure gauge 104 to be indicative of the force with which the coulters are engaging the ground at any time, and this pressure is of course adjusted by the control valve 101. Also shown in Figure 10 is a single acting cylinder 105 connected to the manifold 102.

This is used to control a clutch mechanism (not shown) which controls the operation of the feed devices 55 and 56 so that these only operate when the coulters are lowered to engage the ground.

Means is provided to control two coulters separately as indicated at 106 for the purposes of tram lining in known manner per se when sowing seed.

Figure 11 shows a similar circuit diagram for use with double acting hydraulic cylinders the operation of which is similar in principle. Respective hydraulic pressure control valves 110 and 111 are provided to control the pressure on respective sides of the double acting cylinder 71 and associated accumulators 112 and 113 are provided to take hydraulic fluid from either side of the cylinder 71 as the cou Iter arms move due to uneven ground. Again control of the valves 110 and 111 will control the force with which the coulter arms engage the ground and a pressure gauge 114 will indicate the force. A cylinder 115 is provided in similar fashion to control the operation of the feed devices and means 116 is provided to control two coulter arms for tram lining purposes.

In another arrangement of the machine described above, the coulters with their respective arms are arranged in two groups with alternate ones of the coulters across the chassis being in respective groups. One group is arranged on the chassis to engage the ground in advance of the second group in a staggered pattern. By this means additional clearance may be provided between the coulters when the coulters are close together across the width of the machine, as may be the case where it is desired to increase the number of rows of seed in a given width of ground sown. This is helpful in allowing space for clearance of plant material growing in soil being sown, particularly in the case of direct sowing into unprepared ground.

Claims (21)

1. An agricultural machine comprising a chassis arranged to be supported from the fround and drawn across the ground by means of a tractor vehicle and a number of ground treating implements movably mounted on the chassis with means operative between the chassis and the implements to urge them towards or into the ground, in which the implements are mounted on the chassis so as to extend forwardly from it in use, the arrangement being such that the load imposed on the implement by forward movement over or in the ground reacts to urge the implement onto or into the ground.

2. A machine as claimed in Claim 1, in which the implements are carried on an arm pivotally mounted on the chassis about an axis which is horizontal and transverse to the direction of motion, such arm extending forwards from the chassis in use.

3. A machine as claimed in Claim 2, in which each such implement is provided with a respective arm.

4. A machine as claimed in Claim 1,2 or 3, in which each such implement is provided with a respective hydraulic ram device operative between the chassis and the implement to urge it towards the ground.

5. A machine as claimed in Claim 4, in which means is provided to control the pressure of hydraulic fluid supplied to such hydraulic ram device so that the force with which the implement engages the ground may be controlled.

6. A machine as claimed in Claim 5, in which the hydraulic supply to such hydraulic device includes a gas filled accumulator device arranged to maintain substantially constant hydraulic pressure over the range of movement of the implement relative to the chassis when the implement is engaging the ground.

7. A machine as claimed in Claim 4,5 or 6, in which the mounting of the implements on the chassis is such that a constant pressure in the hydraulic system urging the implements towards the ground results in a constant force of engagement of the implements with the ground.

8. A machine as claimed in any preceding claim, in which the depth of penetration of the implements is controllable by means of a ground engaging wheel system arranged to control the penetration of the implement.

9. A machine as claimed in Claim 8, in which an overall adjustment is provided effective between the ground engaging wheen system and all the implements.

10. A machine as claimed in Claim 8 or 9, in which such wheel system comprises a wheel for each such implement arranged to follow behind the implement in use and to move with the implement relative to the chassis as one unit.

11. A machine as claimed in Claim 10 or 11, in which individual adjustment between the ground engaging wheel and the implement is provided.

12. A machine as claimed in any preceding Claim, in which said ground engaging implements are seed drilling coulters.

13. A machine as claimed in Claim 12, in which the coulters are each mounted so as to be pivotally adjustable about a generally vertical axis, thus to adjust the width of cut which they make in the ground in use.

14. A machine as claimed in any one of Claims 4 to 13, in which the hydraulic rams arranged to urge the implements towards the ground are double acting hydraulic rams to raise or lower the implements relative to the chassis.

15. A machine as claimed in any one of Claims 4 to 13, in which the hydraulic rams arranged to urge the implements towards the ground are single acting rams to lower the implements relative to the chassis with spring means for raising the implements relative to the ground.

16. A machine as claimed in any preceding Claims in which the implements are arranged on the chassis so that a group of them engage the ground in advance of a second group of them.

17. A machine as claimed in any preceding Claims, in which the chassis comprises a single transverse cross beam having a supporting wheel arranged by the end.

18. A machine as claimed in any preceding Claims in which the chassis is provided with a pair of retractable wheels at one side so that the whole implement may be towed sideways for transportation between places where it is used.

19. A machine as claimed in any preceding Claim in which a tow bar is provided at the other side of the chassis for such towing, the tow bar being arranged to telescope into the main chassis when not in use.

20. A machine as claimed in any preceding Claim in which the ground engaging implements are seed drilling coulters, and the coulters are carried on an arm pivotally mounted on the chassis, and in which seed feed tubes are provided passing through such arm immediately behind the axis of the coulter to enable seed to be deposited in the ground beside the rear part of the coulter disc.

21. An agricultural machine substantially as herein described with reference to the accompanying drawings.