GB2056234A - Reversible plough - Google Patents

Abstract

A reversible plough comprising a beam (18) carrying a set of plough shares and mould boards (20, 21) on each side so that the plough can be reversed by turning over the beam. The beam is mounted on a turnover device including a member (9) pivotally connected to a coupling head (1) for connection to a tractor. A vertical pivot (17) connects the beam to the member (9) so that it can also be pivoted in a horizontal plane to a desired angular position relative to the direction of movement, by means of a hydraulic jack (29), and its movement is limited by means of an adjustable chain (40). This enables the optimum position of the beam to be achieved for different types of terrain, and for transporting the plough along roads. <IMAGE>

Description

SPECIFICATION Improvements in reversible supported ploughs The present invention relates to a plough adapted to be mounted on a three-point lifting system at the front of a tractor so that the plough works by being pushed, instead of being pulled, as is usually the case.

Such a type of plough is described in French Patent No. 7430 699 of the 1 itch September 1974, the said plough comprising a rigid chassis provided with a coupling head and several working members supported by a beam.

As compared with drawn or towed ploughs, such a plough has a certain number of advantages, especially for ploughing operations on sloping terrains.

From tests which have been carried out, it has nevertheless been established that there are practical limits to the dimensions of such a plough particularly because of difficulties in travelling over roads and on tracks, and that in addition turning round required considerable power.

An assembly is described in German Patent No.

1 216 597 of the 31 st August 1965, which comprises a tractor provided at the front and at the rear with a three-point lifting device, the front device supporting a plough whose beam carries, on one side, plough-shares and mould boards adapted to work by pushing, while on the other side the plough-shares and the mould boards are adapted to work by being drawn. An identical plough is provided at the rear end of the tractor.

These ploughs are set at an angle in relation to the longitudinal axis of the tractor and the latter is moved alternately in one direction and in the opposite direction. At the end of a field, it is not necessary to turn the tractor through 1 800, but simply to position it parallel to the ploughed terrain at a distance corresponding to the working width, then to cause the beams to turn so that the plough which was working by being pushed is pulled and the other, which was working by being pulled, is pushed.

Such an assembly necessitates a tractor of high power, is very cumbersome and is practically incapable of being transported on roads and paths and does not permit of working in sloping terrain, but only in terrain which is not very uneven.

Moreover, each plough is not in itself a reversible plough, but is a simple plough, since it operates alternately by being pushed and pulled.

The present invention seeks to provide a reversible plough adapted to be supported at the front of a tractor and operating by being pushed and which overcomes the various disadvantages referred to above.

Accordingly the present invention provides a reversible plough of the type comprising a beam carrying a set of plough-shares and mould boards on each side, the arrangement being such that the beam can be turned over to bring either set of plough-shares into engagement with the ground, depending on the intended direction of movement, the plough including a coupling head for connection to a vehicle, vertical pivot means connecting the beam to the coupling head so that the beam can be pivoted in a horizontal plane, the pivot being offset from the turning axis, means for adjusting the angular position of the beam in the horizontal plane, and means for limiting the range of angular movement.

A preferred arrangement of the plough of the invention comprises a beam supporting plough shares and mould boards on both sides, the said beam being carried by a member connected to a coupling head equipped with a hydraulic jack for controlling the turning and provided with means for being fixed to a three-point lifting device of a tractor situated at the front of the latter, the said beam being pivotally mounted on a vertical shaft of the member, the said improvements being characterised in that the pivot shaft of the beam is offset laterally with respect to the turning shaft, a hydraulic jack being inserted between a point intermediate of the length of the beam and the member, means being provided for limiting the angular position of the beam in its working position, the said means comprising a chain fixed by one end to the beam close to its free end and by its other end to the member from the side opposite to the pivot shaft, means being provided for regulating the length of the chain. By means of this arrangement, it is possible firstly, at the moment of turning, to arrange the beam in a direction such that it is balanced and, secondly, to modify the ploughing angle for balancing the tractor-plough assembly in sloping terrains. Finally it is possible to provide long beams having several ploughing members, the assembly neverthelsss being transportable. Moreover, thanks to the chain, the force exerted on the jack at the moment of ploughing is limited and in this way any danger of it being damaged is avoided.

According to another preferred feature of the invention, the jack connected between the member and a point intermediate of the length of the beam is supplied directly by branch pipes connected to the feed ducts of the jack controlling the turning movement, so that when the turning is controlled, the beam automatically pivots in the direction of the turning shaft. Consequently, a particularly simple means is developed which controls the pivoting of the beam at the same time as the turning movement.

Actually, the force necessary for controlling the turning is higher than that controlling the pivoting of the beam, so that when oil under pressure is directed into the body of the turning jacks and simultaneously, by way of the branch pipe provided for this purpose, into the body of the jack controlling the pivoting of the beam, this latter pivots directly before the turning movement.

When the plough has been turned, the pressure rises in the turning jack, since the plough is locked and thus, through the branch pipe provided for this purpose, the beam is automatically controlled by the pivoting jack so as to take up a position corresponding to that of the working position.

Another feature of the invention is concerned with an ease of construction of the plough according to the invention, making it possible, without any modification of the manufacture, to produce just as easily a plough intended to be pushed as a plough intended to be pulled. For this purpose, the beam of the plough comprises at each of its ends means for fixing it selectively by each of its ends to the coupling head.

According to one feature as regards construction, the couplling head comprises a yoke or fork close to one of its ends, between the wings of which a bar ending in a strap at its free end is pivoted on a vertical shaft, while the beam comprises a corresponding strap at each of its ends.

Finally, according to a modification, the head of the plough comprises a yoke or strap close to one of its ends, while it is provided close to the other end with means for hooking on a member for regulating the angular position of the beam, such as a jack or a strut, the said beam comprising at each of its ends a bearing adapted to receive selectivelv a vertical shaft co-oDerating with the bearings of the wings of the fork and at points intermediate of its length with means for hooking on the free end of the regulating or adjusting member.

Thus, depending on when one or other of the bearings of the beam is used, it is possible to provide a drawn or pushed plough.

The invention is now to be described in greater detail, by reference to one particular constructional form which is given simply by way of example and which is illustrated in the accompanying drawings, in which: Figure 1 is a perspective view of a plough according to the invention, Figure 2 is a corresponding plan view of the plough shown in Figure 1, Figure 3 is also a plan view, showing the said plough in a position in which the beam is placed so as to facilitate turning or transport, Figure 4 shows the construction with the elements of the pushed plough of a plough adapted to be drawn.

Figure 5 is a perspective view of a modified form of the invention.

The plough which is represented in the various Figures comprises a coupling head represented as a whole by the reference numeral 1 having two shafts 2 adapted to be fixed to the traction bars of a three-point lifting device and a yoke or fork 3 designed for selectively receiving, in the holes 4, a shaft for the fixing of the third point bar. The head 1 comprises a support 5 on which is fixed a bearing 6 in which is journalled a shaft 7 integral with a bar 8 inserted into a U-section member 9 and fixed in the latter by bolts 1 0. The bar 8 and the shaft 7 are fast with a reinforcing element 11, to which is connected the free end of a rod 12 of a hydraulic jack 13 for controlling the turning of the plough, which jack is adapted to be connected to a distributor provided on the tractor.The section member 9 constitutes the body of the plough and the jack 13 is pivoted on the coupling head 1 on a shaft or pivot 39.

The section member 9 comprises near one of its ends a fork or yoke 1 5, the wings of which have a hole 1 6 drilled therein, the said hole forming a bearing for a shaft 17.

The beam of the plough, which here carries the reference numeral 18, comprises pillars or stanchions 1 9 on which the plough-shares 20 and mould boards 21 are fixed. As will be ciearly seen from Figure 1, the plough is of the reversible type and its various elements, which are well known, will not be described in greater detail here.

At its free end, the beam 1 8 is provided with a strap 22, permitting a support 23 for a land wheel 24 to be secured. The said wheel is adjustable in height according to the running on the land which it is desired to obtain and it is carried by a bar 25 which is capable of pivoting through 1 800 on the support 23, so that once the wheel is adjusted, it is able to permit the working of the land by the operating tools. The bar 25 of the land wheel 24 is movable in the support 23 and the said wheel, during working, rolls in the furrow.

At its end opposite to the fork or yoke 1 5, the section member 9 comprises lugs 26 adapted to support a shaft 27 on which is pivoted the body or housing of a hydraulic jack 28, of which the rod of the piston 29 is pivoted at its free end on a shaft 31 supported by lugs 30 integral with the beam 18.

The jack 13 is a double-action jack, and it is fed from a distributor 52 of the tractor by way of two pipelines 50 and 51, the distributor selectively permitting one or other of the pipe lines to be brought to the admitting position, while that which is not in the admitting position is set for return flow.

Provided on the pipeline 51 which is open from the side of the piston rod is a branch pipe 53 which opens into the jack 28 on the side of the piston rod, while the pipeline 50 has provided thereon a branch pipe 54 connected to the body or housing of the jack 28.

Pivoted on the shaft 27 supported by the lugs 26 is a small plate 44 extended by a threaded rod 45 which is screwed into a tapping in one small side of a frame 42, a locking nut 46 being provided.

The small side of the frame 42 opposite to that provided with the tapping into which is screwed the rod 45 also comprises a tapping, but of opposite pitch to the foregoing tapping, and into this last tapping is screwed a screw 41, one end of which terminates in a ring 47 to which is connected one of the ends of a chain 40, fixed by its other end to the lug 35.

A locking nut 43 is provided on the threaded rod 41.

The frame 42, which is associated with the rods 45 and 41, forms a simple, practical and efficient means for regulating the length of the chain.

In order to control the turning movement, after which the plough has been raised, the introduction of oil into the jack 1 3 through the pipeline 51 is controlled with the distributor 52. As it requires much more pressure in the jack 1 3 for controlling the turning movement than in the jack 28 for controlling the rocking of the beam 1 8 in the direction of the arrow f (Figure 2), the beam first of all rocks into a position for taking up the angular position of Figure 3.

When the turning movement is initiated, an action is carried out on the distributor 52 for connecting the pipeline 51 to the return position, while the pipeline 50 is at the admission position, and thus the body of the plough is pushed up to the external position of the return, where it comes into an abutting position. The pressure then rises in the jack 13 and hence through the pipelines 50 and 54, and the jack 28 is controlled for bringing the beam into the working position (see Figure 2).

The rocking of the beam 1 8 towards its working position is limited by the chain 40, the length of which is previously regulated in order that the angular position of the beam is smaller than the maximum development of the jack 28, in order to avoid the force being carried over to the piston of the latter.

The adjustment by means of the chain is simple and practical and this means represents an inexpensive and very efficient arrangement.

Bearing in mind that the angular position of the beam 1 8 can be very easily modified by acting on the jack 28, it is possible, even during the ploughing operation, to move the said beam further from or closer to the longitudinal axis of the tractor, and this, under certain ploughing conditions, and especially in terrains having a steep slope, permits best possible balancing of the tractor-plough assembly and to carry out the ploughing operation according to the contour lines.

The section member 9 may comprise a series of holes permitting the lugs 26 to be fixed at several different positions, and this may make it possible to increase the possibilities of adjustment with the same jack.

The beam 18, in the vicinity of the strap 22, comprises an ear 33 in which is drilled a hole 34 suitable for receiving the shaft 1 7. At a point intermediate of its length, the beam 1 8 is provided with a lug 35 identical with the lug 30.

As will be seen from Figure 4, starting with elements permitting the development of a pushed plough, it is also possible to obtain a towed or drawn plough. In this case, the ear 33 is inserted between the wings of the fork or yoke 1 5, after having withdrawn the support 23, which in this case is no longer required, and then the shaft 1 7 is so positioned that it extends through the hole 34 and the holes 1 6 of the wings of the said yoke and the angular position of the beam 1 8 is adjusted by inserting a reinforcing member 36 between the lugs 27 and the lugs 35. It is also possible in this case to position the jack 28, but it being accepted that when the tractor is pulled, it is not necessary to modify the angular position of the beam, a hydraulic jack is not justified.

Shown in Figure 5 is a modified constructional form, in which a bar 36, of which the free end carries a strap 37, is pivoted on a shaft 1 7 between the wings or sides of the fork 1 5. In this case, the beam 18, as well as having the strap 22 at one of its ends, is provided at the other end with a strap 38. It is thus possible to provide either a drawn plough or a pushed plough, according to whether the strap 22 or the strap 38 is fixed to the strap 37.

It is apparent that these possibilities are very advantageous as regards the manufacturing cost of the plough.

Obviously, the invention is not limited to the embodiment which has just been described and which has been illustrated in the accompanying drawings. It will be possible for numerous modifications as regards details to be incorporated, without thereby departing from the scope of the present invention.

Claims (9)

1. A reversible plough of the type comprising a beam carrying a set of plough-shares and mould boards on each side, the arrangement being such that the beam can be turned over to bring either set of plough-shares into engagement with the ground, depending on the intended direction of movement, the plough including a coupling head for connection to a vehicle, vertical pivot means connecting the beam to the coupling head so that the beam can be pivoted in a horizontal plane, the pivot being offset from the turning axis, means for adjusting the angular position of the beam in the horizontal plane, and means for limiting the range of angular movement.

2. A reversible plough according to claim 1 in which the means for adjusting the angular pivotal position of the beam comprises a hydraulic jack connected between the beam and the coupling head.

3. A reversible plough according to claim 1 or claim 2 in which the means for limiting the range of angular movement comprises a chain of adjustable length.

4. A reversible plough according to claim 2 or claim 3 in which the turning movement is also controlled by a hydraulic jack, the hydraulic circuits of the turning jack and the pivoting jack are interconnected so that the beam is automatically pivoted when the turning jack is actuated.

5. A reversible supported plough of the type comprising a beam supporting plough-shares and mould boards on both sides, the said beam being carried by a body connected to a coupling head provided with a hydraulic jack for controlling the turning movement and adapted to be connected by pipelines to a distributor and provided with means for being fixed to a three-point lifting device of a tractor situated at the front of the latter, the said beam being mounted for pivotal movement relative to the coupling head on a vertical shaft, characterised in that the pivot shaft of the beam is offset laterally with respect to the turning axis, a hydraulic jack being inserted between a point intermediate of the length of the beam and the body, means being provided for limiting the angular position of the beam in its working position, the said means comprising a chain fixed by one of its ends to the beam, close to its free end, and by its other end to the body from the side opposite to the pivot axis, means being provided for adjusting the length of the chain.

6. A reversible plough according to any preceding claim in which the beam is adapted to be connected to the coupling head by either of its' ends.

7. A reversible plough, according to claim 6, characterised in that the coupling head comprises a fork or strap close to one of its ends, between the wings or sides of which is pivoted, on a vertical shaft, a bar terminated by a strap at its free end, while the beam comprises a corresponding strap at each of its ends.

8. A reversible plough according to claim 6, characterised in that the head of the plough comprises a fork or yoke close to one of its ends, while close to the other end, it is provided with means for the coupling of a member for regulating or adjusting the angular position of the beam, such as a jack or a reinforcing member, the said beam comprising, at each of its ends, a bearing adapted selectively to receive a vertical shaft co-operating with the bearings of the wings or sides of the yoke and, at points intermediate of its length, means for the coupling of the free end of the adjusting member.

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9. A reversible plough substantially as herein described with reference to Figures 1 to 3 or Figure 4 or Figure 5 of the accompanying drawings.