WO1999055136A1

WO1999055136A1 - Semi-mounted gang plough with articulated fixture

Info

Publication number: WO1999055136A1
Application number: PCT/FR1999/000964
Authority: WO
Inventors: Bernard Naud
Original assignee: Charrues Naud
Priority date: 1998-04-24
Filing date: 1999-04-22
Publication date: 1999-11-04
Also published as: AU3426499A; FR2777736A1; PL343626A1; NO20005331D0; FR2777736B1

Abstract

The invention concerns a plough wherein the articulation is arranged between the front section (5) and the rear section (7), comprising two perpendicular pins (11 and 12) forming a cardan universal joint. The rear section (7) is linked to the front section (5) via actuators (17). Said actuators (17) consist each of a couple of coaxial actuating cylinders (19, 20), arranged at some distance from the articulation pins. Said actuators are controlled from the tractor, by means of a first reversing valve (30) activated by means sensitive to the pressure prevailing in the circuit powering the jacks (16) for lifting the fixture, and by the reversing valves which power respectively each of the actuators (17). In normal ploughing position, the operator can control the rear section movement by adjusting the resistance to movement between a null value up to a quasi-rigidifying value. When the bodies are lowered, the operator can intervene to lift the rear section, thereby delaying the penetration of the bodies to reduce the land dimension.

Description

SEMI-REACHED MULTI-SOCS PLOW WITH ARTICULATED FRAME

The present invention relates to semi-mounted multi-coulter plows, the frame of which consists of two sections articulated with respect to each other: a front section connected to the tractor and a rear section linked to the front section, at the level of the carriage. carrier.

This type of plow makes it possible, as recalled in document FR-2 623 687 of the applicant, to carry out plowing while preserving optimum soil depth of the coulters, despite the length of the frame, in vacant lots.

The plow described in the aforementioned document in fact has, in the working position, a certain flexibility in a vertical plane, at the level of the junction device interposed between the front section and the rear section of the frame.

Document FR-2 730 896 shows additional means and in particular the introduction of a jointing device in the form of a universal joint which allows, in addition to freedom of movement of the rear section in the vertical plane, a possibility of transverse movement. This freedom of movement around a vertical axis is particularly advantageous at the end of the line when, after having started to extend the front bodies, the operator begins his turn while having the bodies of the rear section in the active plowing position.

In the two aforementioned documents, the amplitude of the movement of the rear section relative to the front section is limited and thwarted by elastic members which tend to maintain the alignment of the two sections.

This flexibility at the junction also has the advantage when the latter is in the form of a universal joint, to dampen the oscillations of the rear section when the plow is in the transport position.

In document WO 96/26633 of the applicant, provision is made to use elastic members and / or jacks to be able to act on the rear section, at will, and modify its orientation relative to the front section. However, given the speed of maneuvers at the end of the lines and the difficulty of obtaining a precise position of the rear section relative to the front section, the use of simple conventional jacks very quickly reveals the limits of use of this mechanical. The present invention provides means which make it possible to effectively control the positioning of the rear section, with respect to the front section, without imposing on the operator complicated interventions to achieve the desired positioning. The invention makes it possible in particular to intervene on the rigidity of the connection between the front section and the rear section, in order to be able, during plowing, to more or less force the rear section to align with the front section, or else the leave free.

The invention also has the advantage of simplifying the work of the operator during the maneuvers and in particular the maneuvers at the end of the line while allowing a reduction in the length of the scouts and the maneuvering time.

The invention also makes it possible to reduce the length of the lookouts at the start of the line. According to the invention, the means which make it possible, at the junction joint, to secure the front and rear sections, consist of actuators interposed between said sections, making it possible to achieve at least one alignment of the latter based on programmed positions corresponding for example to cylinder end positions and these actuators are implemented from the tractor to adjust and establish a resistance level in order to counteract the movement of the rear section relative to the front section, in a range from '' total freedom to an absence of freedom which corresponds to a quasi stiffening of the joining device without the latter however being able to be completely blocked. Still according to the invention, each actuator consists of two co-axial cylinders whose drums for example are coupled bottom to bottom and whose patellar ends of the rods are anchored for one on the front section and for the other on the rear section.

According to another arrangement of the invention, the means for implementing the actuators consist of a reversing distributor controlled by a pressure-sensitive sequence valve prevailing in the hydraulic circuit serving to supply the cylinders for lifting the bodies plowing, which cylinders are arranged at the support carriage, which reversing distributor has a rest position and an inverted active position obtained when the pressure in said lifting cylinders is greater than a predetermined threshold displayed at said sequence valve. Still according to the invention, the actuator supply circuit, located downstream of the pilot-operated reversing distributor, is connected, for each actuator, to the large chamber of one of the jacks constituting the actuator and to the small chamber of the another cylinder of the same actuator, which cylinders operate as single-acting cylinders and are implemented directly by means of the tractor distributor when said distributor is placed either in the body lifting position or in the body lowering position, which actuator supply circuit further comprises an accumulator device of the nitrogen ball type which makes it possible to maintain, under all circumstances, a certain elasticity between the front and rear sections. According to another arrangement of the invention, the supply circuit for the cylinders of the body lifting carriage comprises a closing valve making it possible, during transport, to maintain said cylinders in the active lifting position, independently of any action on the tractor distributor so as to ensure safety during transport in particular. According to another arrangement of the invention, the supply circuit of the actuating cylinders, through the piloted distributor, comprises, upstream of said distributor, a non-return valve and, bypassing this valve, a throttling valve which makes it possible to release at will the pressure and drop it in the circuit of said actuator cylinders, by placing the tractor distributor in an ad-hoc position, to adjust the degree of suspension of the rear section, during transport, which section oscillates around the transverse horizontal axis of the junction device, which suspension takes place under the control of the accumulator interposed in the actuator supply circuit.

According to another arrangement of the invention, the return circuit of the actuating cylinders comprises, upstream of the piloted distributor, a valve for closing the circuit which ensures the safety of the rear section in position transport, against a risk of falling in the event of loss of pressure following an operation of the tractor distributor.

To delay the introduction of the bodies of the rear section during the attack on a new line, it is necessary to be able to act on the actuators cylinders in order to raise the rear section.

To this end, according to a variant of the invention, the jacks of each actuator are of the double-acting type and each jack of one of the actuators is connected to one of the jacks of the other actuator in a crossed fashion, that is to say that the large chamber of one is connected to the small chamber of the other and vice versa, and the supply of said cylinders takes place through two reversing distributors each located on a branch of the distributor's downstream circuit piloted reverser with, in addition, a return line crossing said reversing distributors, which return line joins on the one hand, the return line of the return circuit of the piloted reversing distributor, through a non-return valve and, on the other hand , the pressurized supply line of said piloted reversing distributor, also through a non-return valve, which pressurized feeding line allowing, on the one hand, when said reversing distributors associated with each actuator is nt in the rest position, adjust and control at will the resistance to movement of the rear section relative to the front section when they are substantially aligned with respect to each other, and on the other hand, when one of said reversing distributors is in the inverted position, under the effect of at least one position sensor located on the plow detecting a right or left position as the case may be, to be able to raise the rear section at will in order to delay the penetration of its bodies by plowing when attacking a new skate.

Still according to the invention, each actuator supply reversing distributor is controlled to pass from its rest position to its inverted position, by means of sensors for detecting the working position to the right or to the left, which sensors are each associated with a electromagnetic relay, for example, which they control and operate when they are in an inactive position, i.e. when the plow is in a position intermediate during the inversion phase, between the extreme right or left positions.

According to another arrangement of the invention, the actuator circuit, between the pilot-operated reversing distributor and the reversing distributors associated with each actuator, comprises a pressure switch, which pressure switch controls a relay which it operates when the actuators are under pressure, which relay then supplies in parallel with the right and left position sensors, the relays associated with the latter, so as to maintain, when the plow is placed in the working position on the right or on the left, the reversing distributor corresponding to said position in an inverted active position, thus offering the possibility of lifting the rear section at will and maintaining it in this position as long as the tractor distributor is not placed in the floating position, that is to say open, during the attack of a new ray.

Still according to the invention, the rear section is raised by means of an intervention on the tractor distributor by placing it either in the body lifting position, or in the body lowering position, which lowering is controlled by means of a flow restrictor interposed on the lift cylinder circuit, between said lift cylinders and the connection of the sequence valve which implements the piloted distributor, which restrictor makes it possible to place said piloted distributor in the rest position due to deactivation of said sequence valve, which has the effect of authorizing the sending of pressurized fluid via the tractor distributor in the lowering position of the bodies, in the actuator circuit for raising said rear section simultaneously with the controlled lowering bodies. To offer the operator even more possibilities for the use of this type of equipment, the invention provides means which make it possible to act on the position of the rear section.

These intervention possibilities allow in particular the lifting at will for certain embodiments and, for all embodiments, the possibility of maintaining the rear section in the raised position during work and during certain maneuvers such as for example lifting the built of chaurrue. The invention also consists of a process for controlling and adjusting the movement of the rear section of an articulated semi-mounted plow, relative to the front section, which sections are connected by means of a seal and actuators as described previously, and this method consists in adjusting, from the tractor, the pressure of the hydraulic fluid present in the actuating members, from a value corresponding to total freedom of movement to a value which corresponds to a quasi-rigidity of the junction device, without reaching total blockage, so as to place and maintain the two sections substantially in alignment with one another. Still according to the invention, the method also consists in completely freeing the rear section by canceling the pressure of the fluid circulating in the actuating members, by involving the operator on the tractor distributor to lift the plowing bodies, that is to say - say send pressurized fluid into the lifting cylinders arranged on the support carriage. According to another arrangement of the invention, the method also consists in aligning the front and rear sections during the operation of lifting the plowing bodies, by introducing hydraulic fluid under pressure into the actuating members, as soon as the pressure of said fluid in the lift cylinders of the carriage reaches a predetermined threshold. According to another arrangement of the invention, the method consists in raising the rear section by means of the actuating members, after turning the plowing bodies and this before the descent of said bodies, in the absence of a restrictor on the supply circuit of the lifting cylinders, or during the descent of said bodies, in the presence of a restrictor on said circuit. According to another arrangement of the invention, the method consists in delaying the descent of the bodies of the rear section to reduce the size of the stand, that is to say in maintaining said section in the raised position by blocking the pressure of the hydraulic fluid in the actuators by the return of the tractor distributor to the neutral position. The invention will be further detailed with the aid of the following description and of the appended drawings given for information, and in which: - Figure 1 shows a reversible plow, multi-coulter semi-mounted comprising a junction device in the form of a joint, at the level of the support carriage;

- Figure 2 shows schematically, a portion of the plow at the support carriage and the joining device, with a particular representation for the wheels showing a wheel in transport position and a wheel in working position;

- Figure 3 shows in perspective, schematically, the junction device in the form of a gimbal type joint, with the actuator members which allow the front and rear sections to be connected and to maintain alignment;

- Figure 4 shows schematically the hydraulic circuit of the plow in a first version allowing in particular to control the alignment of the front and rear sections;

- Figure 5 shows the hydraulic circuit when the bodies are raised and when the actuators are under pressure to achieve alignment of the front and rear sections for example, to allow the operation of turning the plow;

- Figure 6 shows the hydraulic diagram according to an alternative embodiment, which diagram is supplemented with respect to the previous figures 4 and 5 to allow complete control of the actuator cylinders in order to carry out at will the lifting of the rear section so as to delay the introduction of the bodies of said rear section;

- Figure 7 shows the hydraulic circuit of Figure 6 when the rear section is held in the raised position before the descent of the plowing bodies;

- Figure 8 shows schematically the electrical circuit for intervention on the rear section, which circuit is in transport or intermediate phase of reversal;

- Figure 9 shows the electrical circuit when the plow is in the position turned right, before or during the descent of the bodies;

- Figure 10 shows the electrical circuit after the descent of the rear section, the latter being free; - Figure 11 shows the hydraulic diagram of Figure 6 modified to allow manual control, from the tractor, movements of the rear section.

The long plows as shown in Figure 1, are connected to a tractor 1 by means of a coupling head 2, which head is mounted by means of a conventional structure 3 on the lifting system of the tractor, and it comprises a turning system 4 when, as shown in said figure, it is a reversible plow.

This plow has a front section 5 which carries bodies 6 and a rear section 7 which also carries some plowing bodies 6. The front and rear sections form the frame 8 of the plow and they are separated by a junction device 9 which located at the level of the support carriage 10.

This junction device is in the form of a universal joint and includes a hinge pin 11 which is horizontal when the plow is in the working position as shown in Figure 1, substantially perpendicular to the direction of travel. This axis 11 allows the rear section to oscillate in a vertical vertical plane so as to better match the relief of the terrain in particular in the wave terrain as shown in the figure.

The junction device 9 also includes an articulation axis 12 perpendicular to the axis 11, which allows when the plow is in the working position, to obtain a movement of the rear section, transversely, to the right or to the left. This axis 12 also allows, when the plow is in the transport position, to obtain a possibility of oscillation of the rear section relative to the front section and, by means of the means described below, to obtain a damping which facilitates driving the plow in the transport position and, above all, cleaning the junction device and avoiding breakage.

For reasons of clarity, all the elements of the joining device 9 are not shown in FIG. 1; they are shown in Figures 2 and 3 and detailed below. FIG. 2 shows the part of the frame of the plow at the level of the support carriage 10, that is to say the rear part of the front section 5 and the front part of the rear section 7. This part of the frame is shown seen from the side when the plow is in the transport position, carried by the wheels 13, or seen from above with the wheel 13 'disposed behind the last body 6 of the front section, in the normal plowing position, the other wheel of the carriage not being shown in this plowing position. In the transport position, the axis 11 is located in a vertical plane while the axis 12 is horizontal.

Between axes 11 and 12, there is an intermediate piece 14 which forms a sort of cross between the front section 5 and the rear section 7. For construction convenience, axes 11 and 12 are offset longitudinally: axis 11 is located for example at the rear end of the front section 5 and the axis 12 is located at the front end of the rear section 7.

The carriage 10 is articulated on the front section 5 by means of an axis 15 interposed between the two. This carriage is a conventional carriage already described in other documents and in particular the aforementioned documents. In fact it is the frame 8 and the front section 5 which rotates around the axis 15, which axis is located in the vertical median plane when the plow is in the transport position and it is placed in the direction of movement of the plow when the latter is in the normal working position.

It is the pivoting of the frame 8 of the plow, that is to say of the front section 5 and the rear section 7, around this axis 15 which makes it possible to work, as the case may be, to the right or to the left and which also makes it possible to place the bodies horizontally, that is to say in the transport position.

The carriage 10 comprises jacks 16 which make it possible to lift the frame of the plow, that is to say to lift the plowing bodies 6 at the end of the line for example, to remove them from the ground. These same jacks 16 make it possible to lower the bodies at the start of the line to start a new plowing.

These jacks 16 also make it possible to keep the frame raised during transport.

The joining device marked 9 in FIG. 1 includes the hinge pin 11 which is substantially vertical when the plow is in the transport position and horizontal when the plow is in the working position; it also includes the hinge pin 12 which is horizontal in the transport position and vertical in work position. These two axes 11 and 12 provide a connection of the universal joint type between the front section 5 and the rear section 7.

The simple presence of the articulation joint consisting of the two axes 11 and 12, offers complete freedom to the rear section 7. But to allow the operations of turning the plow for example and also to allow its transport, the rear section 7 is linked to the front section 5 by means of actuator members 17 arranged on either side of the axis 11 and at a distance from the axis 12.

These actuators 17, shown in Figures 2 and 3, each consist of a pair of co-axial cylinders 19 and 20 secured on the same axis at the bottom of their respective barrel. The patellar ends 21 and 22 of the jacks 19 and 20 respectively are anchored, one on a yoke 23 secured to the front section 5 and the other on a yoke 24 arranged at the front end of the rear section 7. The travel of each of these jacks 19 and 20 is of the order of a few centimeters, 10 cm for example. These jacks are adjusted so that, for each actuator, when one of the jacks is in full extension at the end of the stroke and the other in full retraction at the end of the stroke, the rear section 7 is in alignment with the section before 5, as if the frame were in one piece over the entire length of the plow, placing all the bodies 6 in planes parallel to each other and in a horizontal median plane passing through the axis 11 when the plow is in position job.

The actuators 17 are each arranged on either side of the above median plane, that is to say on the same side as the right and left plow bodies. We will therefore use, as needed, the benchmarks 17G to designate the actuator which is located on the side of the bodies working on the left and 17D for the actuator which is located on the side of the bodies working on the right, and we will also use these marks G and D for cylinders 19 and 20, as required. In the transport position, the actuators 17 are located above the axis

12, on either side of the median plane. The distance from the plane passing through the axes of these actuators, relative to the axis 12, is of the same order as the distance of each of these actuators relative to the median plane, passing through the axis 11.

Figure 3 shows schematically in perspective, the area of the junction device showing the actuators 17G and 17D with the barrels of the cut-away cylinders.

Thus, there is the rear end of the front section 5 which includes the articulation axis 11, which axis allows the movement of the rear section in a vertical plane in alignment with the direction of advance when the plow is in the working position . The front end of the rear section 7 comprises the axis 12 which is perpendicular to the axis 11 and it is this axis which allows a lateral movement, when the plow is in the working position, and a movement in the median vertical plane when the plow is in the transport position.

The intermediate part 14 between the two axes constitutes the crosspiece of this connection joint between the front 5 and rear sections 7. The control and piloting of this articulation joint is effected by means of the actuators 17G and 17D. These actuators as shown above in Figure 2, each consist of two identical cylinders 19 and 20 whose drums are joined bottom to bottom, welded for example. The end 21 and 22 of each of these jacks is anchored by means of yokes 23 and 24, respectively, on the rear part of the front section 5 and on the front part of the rear section 7.

Preferably, the rods of these different jacks are adjustable to allow an adjustment of the position of the front section relative to the rear section 7. As detailed below in connection with the hydraulic diagrams, it is possible to obtain a precise position of the rear section relative to the front section using the limit switches of the cylinders 19 and 20, which allows immediate and precise alignment of the rear section relative to the front section. FIG. 4 represents the hydraulic diagram with the components situated on the one hand on the plow, to the right of the thin dashed line marking the separation, and on the other hand to the left, on the tractor. On the tractor, there is the distributor 26, which can be operated by the operator. This distributor has a neutral position F for which the circuits are closed both the supply circuit 27 and the return circuit 29. This neutral or closed position also makes it possible to maintain the pressures in the state in the hydraulic circuits and components of the plow. On either side of the neutral position, there is a raised body position mentioned by the letter L and a lowered body position mentioned by the letter D. The lowered body position is located between the neutral position and a floating position or open marked with the letter O. In this floating position, the supply circuit 27 is closed while the return circuit 29 is open on the two supply and return lines of the plow circuits, that is to say that this position allows to remove the pressure in the hydraulic circuits and components of the plow.

For the plow part, there are the jacks 16 which are arranged at the level of the carriage 10. These jacks 16 make it possible to lift the frame 8 of the plow to remove the bodies from the ground or to lower said frame to return said bodies to the working position .

There are also the actuators 17G and 17D each consisting of the cylinders 19 and 20. The actuators 17 are supplied with power through an inverter distributor 30 shown in the rest position. This reversing distributor 30 is controlled by means sensitive to the pressure prevailing at the cylinders 16 of the carriage 10. Preferably, this reversing distributor 30 is used to pass from its rest position to its inverted position by a valve 31 of the sequence valve type. The change of state of this sequence valve takes place when the pressure in the circuit 32 which supplies the lifting cylinders 16 reaches a predetermined threshold. This threshold is established according to the weight of the plow and the number of bodies arranged on the rear section and also according to the maximum pressure supplied by the tractor.

Preferably, this threshold is located above the value of the pressure reached in the jacks 16 when the latter reach their normal active position for lifting the frame and are in full extension at the end of the stroke. The distributor 30 reverses by changing position as soon as the valve 31 connected to the circuit 32 is activated, that is to say when the pressure in said circuit 32 reaches the predetermined threshold. The distributor 30 is kept in the rest position when the pressure prevailing in the jacks 16 is between 0 and the predetermined threshold.

The circuit 33 which is used to supply the actuators 17G and D, and which is located downstream of the piloted distributor 30, makes it possible to supply simultaneously for each actuator, for example the small chamber of the cylinder 19 and the large chamber of the cylinder 20. The cylinders 19 and 20 are of the single acting type. Thus, when the hydraulic fluid is sent under pressure in the circuit 33, each actuator 17G and D reacts in the same way in that the jacks 19 fully retract and the jacks 20 are positioned in full extension so as to establish positions stable and fixed programmed in advance which correspond to limit switches, and which make it possible to obtain, as mentioned previously, well-established positions of alignment for the rear section with respect to the front section 5.

A hydraulic accumulator 34, of the nitrogen ball type, is positioned on the circuit 33 so as to maintain, at all times, a certain flexibility at the level of the actuators 17 and consequently, at least a certain flexibility under all circumstances for the rear section 7. A joint or movement is thus obtained, the freedom of which is controlled. We can indeed establish at will a resistance which impedes the movement of the rear section 7 with respect to its two articulation axes 11 and 12. This resistance can be established between a value which is zero when the pressure is zero in the circuit actuators 17 up to a maximum value which corresponds to a virtual immobilization of the rear section relative to the front section, without however reaching a total blockage taking into account the presence of the accumulator 34. Still in FIG. 4, it is noted, represented in thin dashed lines, an electro-valve 35 arranged on the circuit 33, preferably upstream of the hydraulic accumulator 34, between the latter and the distributor 30. This non-return type electro-valve 35 is controlled directly from the tractor, by any suitable means such as for example a simple switch; it allows the operator to block, as he sees fit, the pressure which is established in the circuit 33. Thus, for example, he can maintain the rear section in the raised position or in a position aligned with the front section as required.

The circuit 32 which is used to supply the jacks 16 comprises, upstream of the connection of the sequence valve 31, a tap 36 which makes it possible to isolate the circuit 32 in particular when, as shown in FIG. 5, the jacks 16 are in the active position of lifting of the frame, for the transport position. The presence of this tap 36 constitutes transport security in order to lock the jacks 16 in the active lifting position.

FIG. 5 shows the distributor 26 of the tractor in the normal position for lifting the bodies. In this position, the valve 36 is open and allows actuation of the jacks 16 to lift the bodies. When these jacks 16 arrive at the end of the race, the frame being raised, the pressure rises to the point of reaching the predetermined threshold which allows the implementation of the sequence valve 31 and, consequently, the reversal of the distributor 30.

As long as the pressure threshold is not reached to involve the valve 31, it is noted, as shown in FIG. 4, that the circuit 33 serving to supply the actuators 17 is connected through the distributor 30, to the circuit 29 returning to the tank. In this configuration, the actuators 17 are both inactive, that is to say that the articulation is completely free both around the axis 11 and the axis 12. Thus, at the end of the line, when the operator manipulates the distributor 26 to lift the bodies using the jacks 16, the pressure possibly existing in the actuators 17 is released completely. The rear section 7 is completely free relative to the front section so that the bodies remain on the ground and, in addition, the front section 5 can be misaligned laterally with respect to the rear section 7 in the event of a maneuver such as for example a right turn or left as appropriate.

As soon as the jacks 16 reach the end of the stroke, the pressure rises in the circuit 32 and, due to the reversal of the piloted distributor 30 under the effect of the valve 31, the pressurized fluid coming from the tractor reaches, via circuit 33, the jacks 19 and 20 of the actuators 17G and 17D as shown in FIG. 5. Pressurizing the actuators 17 has the effect of forcing the rear section 7 to s align with the front section 5. Thus, at the end of the line, the bodies 6 of the rear section 7 come out of the ground as the pressure increases in the actuators 17.

At the end of the lifting of the frame 8, the operator releases the distributor 26 which is automatically placed in the neutral position F. In this position, the pressure is maintained in all the circuits and in particular in the circuit 32 of the lifting cylinders 16 and the actuator supply circuit 33.

In the transport position, when the pressure prevails in the circuit 32 of the lifting cylinders 16 and in the circuit 33 of the actuators, after having isolated the circuit 32 by means of the valve 36, the pressure in the circuit 33 can be adjusted by means of the valve choke 37. To carry out this operation, it suffices to place the distributor 26 in the floating position O and to regulate by means of the tap 37 the pressure in the circuit, which allows the rear section 7 to be placed under the control of the damper 34.

To improve safety, a valve 39 is also provided on the return circuit 40, between the piloted distributor 30 and the distributor 26 of the tractor, which valve 39 is positioned on the plow like the valve 36 and the valve 37.

The throttling valve 37 is placed in derivation of a non-return valve 38 which is located on the plow, on the supply circuit 41 between the distributor 26 of the tractor and the reversing distributor 30, which valve is located downstream of the connection. of circuit 32, between the input of this circuit 32 and the reversing distributor 30.

We also note, bypassing the sequence valve 31, a non-return valve 42 which releases the actuating pressure of the distributor 30. To raise the rear section 7 and delay the descent of the bodies of said rear section beginning of the line, in order to reduce the length of the guards, it is necessary to use double-acting cylinders at the level of the actuators 17 and to control these cylinders to obtain different lengths at the actuators.

There are provided, FIGS. 6 et seq., Additional means in the form of reversing distributors 45G and 45D used to produce a cross supply of the actuators of the actuators 17G and D.

The actuator supply circuit 33 splits to pass through each of the reversing distributors 45.

There is also a cross supply at the actuator cylinders, that is to say that the large chamber of the cylinder 19G of the actuator 17G is connected to the small chamber of the cylinder 20D of the actuator 17D. The small chamber of the cylinder 19G of the actuator 17G is connected to the large chamber of the cylinder 20D of the actuator 17D.

And the same goes for the cylinders 19D and 20G of the actuators 17D and 17G respectively. There is also a return circuit 46 common to the two reversing distributors 45G and D. This return circuit is connected to the return circuit 40 by means of a non-return valve 47 as well as to the supply circuit 41 by the through another check valve 49.

The valves 47 and 49 prohibit the introduction of the pressurized fluid into the return circuit 46, when handling the distributor 26 of the tractor.

The reversing distributors 45G and D are implemented by means of a control circuit which is shown in FIGS. 8, 9 and 10. It is noted that these distributors 45G and D do not change anything in the operation described above in connection with FIGS. 4 and 5, when they are in the rest position, as shown in FIG. 6.

The inversion of one or other of the distributors 45 makes it possible, as shown in FIG. 7, to obtain for one of the actuators, a total retraction of its two jacks while the other actuator sees its two jacks expanding. total, and each time the cylinders 19 and 20 of each actuator are at the end of their travel.

This situation makes it possible to misalign the front and rear sections and in particular to pivot the rear section 7 relative to the axis 11 which has for effect, when the plow is positioned with bodies to the right or to the left for plowing, to raise the rear bodies and to delay their introduction into the ground when starting a new line.

The inversion of one or other of the distributors 45G and D comes from information obtained by appropriate sensors not shown in FIG. 2, positioned on the plow for example, which make it possible to detect the working position to the right or to left, at the end of the plow turning operation.

FIG. 8 shows an electrical diagram which includes sensors 51 sensitive to the left or right position of the plow: a sensor 51 G, in the form of a switch and a sensor 51 D of the same type.

When they are in the inactive position, as shown in FIG. 8, these sensors 51 keep the circuit of the reversing distributors 45 open, that is to say that these distributors 45 are in the rest position. In the rest position as shown in FIG. 8, the sensors 51 allow the supply by means of the circuits 52, and the placing in active position of the relay contacts 53G and 53D. These relays 53 when activated as shown in FIG. 8, make it possible to close a portion of the circuits 54 which serve to supply the right and left reversing distributors 45 respectively.

Thus each distributor 45 is subject to a double condition in order to be supplied: on the one hand, its corresponding relay 53 must itself be supplied and, on the other hand, the corresponding sensor 51 must also be in the active position. to close the circuit 54. The relays 53 are supplied and placed in the active position when the sensors 51 are in the inactive position. Note, however, that these relays 53 are supplied in parallel to be placed in the active position by means of an additional relay 55 which is itself placed in the active position under the effect of a switch 56. This switch 56 is set to works by means of a pressure switch 57 connected to the hydraulic circuit 33 which is used to supply the actuators 17. Thus, when a certain pressure prevails in the hydraulic circuit 33, the switch 56 is closed as shown in FIG. 9. In the closed position, this switch 56 makes it possible to put the relay 55 in the active position, which supplies and puts the two in active position. relay 53G and D. The switch 56 is placed in the active position when the pressure prevails in the actuator circuit, that is to say in particular when the plow is raised during the turning maneuver.

At the end of the reversal, the sensor 51 D for example, changes state, as shown in FIG. 9, reversing its contacts so as to supply the reversing distributor 45D, placing the latter in the inverted active position as also shown in FIG. 7 on the hydraulic diagram. .

Note that the relay 53D remains in the active position, supplied by the relay 55 which also remains in the active position due to the closing of the switch 56 of the pressure switch 57. In this configuration, it is possible to raise the rear section by placing the tractor distributor 26 in the lifting position L.

Note, in Figure 7, the presence of a flow restrictor 59 on the circuit 32 for supplying the lifting cylinders 16. This flow restrictor 59 makes it possible to control the speed of descent of the frame of the plow. Thus, by placing the distributor 26 of the tractor in the lowering position D, the pressure is canceled in the circuit 32 and at the level of the sequence valve 31, which has the effect of placing the piloted distributor 30 in the rest position thus allowing to power the actuators 17 and in particular to raise the rear section simultaneously with the general descent movement of the frame of the plow. This particularity allows in particular to save time in the maneuvers.

This flow restrictor 59 is placed in derivation of a non-return valve 60, and it is located between the connection of the sequence valve 31 and the jacks 16.

To return the bodies of the rear section 7 to activity during the attack on a new line, it suffices to place the distributor 26 of the tractor in the open floating position O which has the immediate effect of releasing the pressure in the circuit 33 supplying the actuators, and of opening the switch 56 of the pressure switch 57. The switch 56 being open, FIG. 10, the relay 53D n 'is no longer activated and opens the circuit 54D which activates the reversing distributor 45D. This 45D reversing distributor then resumes its rest position and we find the hydraulic diagram of use of Figure 6, that is to say the possibility of controlling at will the stiffness of the joint, leaving the rear section 7 a freedom total with respect to the front section or controlled freedom by more or less braking the movement as necessary. FIG. 11 shows an alternative embodiment of the means for implementing the actuators 17D and 17G which allows the operator to intervene directly, from the tractor cabin, to modify the position of the rear section and in particular the lifting or l 'to lower.

The driver has a box 60 installed in the tractor cabin. This box 60 is connected, by means of wires 61, to each of the reversing distributors 45D and 45G.

This box 60 consists of a switch with three positions: a neutral position N, a position D corresponding to plowing on the right which allows, on the one hand, to reverse, for example, the reversing distributor 45D and, on the other hand, by placing the main distributor in position D, that is to say lowering, supplying the actuators 17D and G to lift the rear section 7.

This embodiment shown in Figure 11 simplifies installation and eliminates the electrical components shown in Figures 8 to 10 which constitute a kind of option. Similarly, as an option, these various embodiments may include, as illustrated in FIGS. 6 and 11, in thin dashed lines, an electro-valve.

35, identical to that which has been detailed previously in connection with FIG. 4.

This electro-valve 35 is located in the same way on the circuit 33 by which the actuators are supplied, preferably between the accumulator 34 and the distributor 30.

Unlike the example illustrated in FIG. 4, the control of this electric valve 35 in the case of FIGS. 6 to 11 is carried out automatically. simultaneously with the implementation of each of the distributors 45 (45d and 45G) as appropriate.

This construction makes it possible to maintain the rear section of the plow in the raised position for certain maneuvers such as for example the raising of the frame by means of the jacks 16 of the carriage.

Claims

- CLAIMS - 1.- Semi-mounted multi-share plow whose frame (8) consists of two sections: - a front section (5) connected to the tractor and - a rear section (7), which sections are linked to the level of the support carriage (10) on the one hand, by a junction device (9) of the universal joint type with two perpendicular axes (11 and 12), one being transverse with respect to the direction of advance of the plow and horizontal during plowing, the other being vertical in the plowing position and, on the other hand, by means of securing like cylinders arranged symmetrically on either side of said horizontal axis, at a distance from said vertical axis, and capable of be implemented by appropriate means characterized in that the securing means consist of actuators (17) interposed between said sections (5 and 7), making it possible to carry out at least one alignment of the latter based on corresponding programmed positions t for example for the end of travel of the cylinders constituting said actuators, and in that the means for implementing said actuators (17) allow, from the tractor, to adjust and establish a resistance level to counteract the movement of the rear section (7) relative to the front section (5), in a range from total freedom to an absence of freedom corresponding to a quasi-stiffening of said joint, without the latter being able to be blocked.

2.- semi-mounted multi-coulter plow according to claim 1, characterized in that each actuator (17) consists of two identical and co-axial cylinders (19, 20), the drums of which are coupled bottom to bottom and of which the patellar ends of the corresponding rods are anchored for one on the front section (5) and for the other on the rear section (7), which jacks are such that when one of the jacks (19) of each actuator is fully retracted and the other jack (20) for example fully expanding, said front and rear sections are aligned.

3.- semi-mounted multi-coulter plow according to claim 2, characterized in that the means for implementing the actuators (17) consist of a reversing distributor (30) implemented by a sequence valve (31 ) controlled by the pressure prevailing in the circuit (32) serving to supply the jacks (16) for lifting the plowing bodies, arranged at the level of the support carriage (10), which distributor (30) has a rest position which is maintained when the pressure prevailing in said cylinders (16) is between 0 and a predetermined threshold, and an inverted position when the pressure is greater than said predetermined threshold.

4.- semi-mounted multi-coulter plow according to claim 3, characterized in that the circuit (33) for supplying the actuators (17), located downstream of the piloted distributor (30), is connected, for each actuator, to the large chamber of one of the jacks constituting an actuator, and to the small chamber of the other jack of this same actuator, which jacks operate as single-acting jacks and are implemented directly through the distributor (26) disposed on the tractor, when said distributor is placed either in the body lifting position or in the lowering position of said bodies, which supply circuit (33) further comprises an accumulator device (34) of the type nitrogen ball, to maintain a possibility of movement of the rear section (7) and dampen the movements of the latter.

5.- semi-mounted multi-coulter plow according to claim 4, characterized in that the circuit (32) for feeding the jacks (16) of the lifting carriage, comprises a tap (36) for closing said circuit during transport, to maintain said jacks in the active lifting position, independently of any action on the tractor distributor so as to ensure the safety of the plow in the transport position.

6.- semi-mounted multi-coulter plow according to any one of claims 4 or 5, characterized in that the circuit (33) serving to feed the actuators (17) comprises, upstream of the piloted distributor (30), a non-return valve (38) and, bypassing this valve, a throttle valve (37) which makes it possible to drop the pressure in said actuator circuit to offer a certain suspension flexibility to the rear section (7), in the transport position , around the transverse horizontal axis (12), which suspension takes place under the control of the accumulator (34).

7.- semi-mounted multi-coulter plow according to any one of claims 4 to 6, characterized in that the return circuit (40) of the actuators (17) comprises, upstream of the piloted distributor (30), on the plow , a closing tap (39) which ensures the safety of the rear section (7) in the transport position.

8.- semi-mounted multi-coulter plow according to any one of claims 4 to 7, characterized in that the circuit (33) serving to supply the actuators (17) comprises an electro-valve (35) preferably arranged in upstream of the accumulator device (34), between the latter and the distributor (30), which electro-valve (35) is controlled from the tractor, by means of a switch.

9.- semi-mounted multi-share plow according to any one of claims 1 to 3 and 5 to 7, characterized in that the jacks of each actuator are of the double-acting type and each jack of one of the actuators is connected to one of the cylinders of the other actuator crosswise, that is to say that the large chamber of one is connected to the small chamber of the other and vice versa, and the supply of said cylinders is performs through two reversing distributors (45) each located on a branch of the downstream circuit (33) of the piloted distributor, with, in addition, a return line (46) crossing said reversing distributors, which return line (46) joined by a on the one hand, the return line of the return circuit (40) of the pilot-operated distributor (30), through a non-return valve (47), and, on the other hand, the pressure supply line (41) of the distributor piloted (30), also through a non-return valve (49), which line (41) allowing, on the one hand, when the reversing distributors (45) are in the rest position, adjusting and controlling at will the resistance to movement of the rear section (7) relative to the front section (5) when they are substantially aligned with respect to each other and, on the other hand, when one of said reversing distributors (45) is in the inverted active position, to be able to raise said rear section at will in order to delay the penetration of the plow bodies during the attack on a new line .

10.- semi-mounted multi-coulter plow according to claim 9, characterized in that each reversing distributor (45) serving to supply the actuators (17) is implemented from a housing (60) of the three-position switch type, arranged on the tractor, available to the operator.

11.- semi-mounted multi-coulter plow according to claim 9, characterized in that each reversing distributor (45) supplying the actuators (17) is used to pass from its rest position to its inverted position, by means sensors (51) detecting the right or left working position of the plow, which sensors (51) are each associated with a relay (53) which they operate when they are in an inactive position, that is to say say when the plow is in the inversion phase for example.

12.- semi-mounted multi-share plow, according to claim 11, characterized in that the supply circuit (33) of the actuators (17), between the piloted distributor (30) and the reversing distributors (45), comprises a pressure switch (57), which pressure switch controls and activates an electromagnetic relay (55) when the actuators (17) are under pressure, which relay (55) supplies in parallel with the right or left position sensors (51), the relays ( 53) associated with said reversing sensors and distributors (45), so as to maintain, when the plow is placed in the working position on the right or on the left as the case may be, the corresponding reversing distributor (45) in an active reverse position, thus offering the possibility of carrying out a lifting movement of the rear section (7) at will and of maintaining it in this position as long as the distributor (26) of the tractor is not placed in the floating position (open) during the attack of a new the line.

13.- semi-mounted multi-coulter plow according to claim 12, characterized in that the lifting of the rear section (7) is carried out by means of the distributor (26) of the tractor placed either in the lifting position of the bodies, or in the lowering of the bodies, which lowering is controlled by means of a flow restrictor (59) interposed between the lifting cylinders (16) and the connection of the sequence valve (31) which implements the piloted distributor (30), which restrictor (59) allows the piloted distributor (30) to be put in the rest position, which has the effect of allowing fluid to be sent under pressure via the tractor distributor (26) in the down position, in the actuator circuit (17).

14.- semi-mounted plow according to any one of claims 9 to

13, characterized in that it comprises, on the circuit (33) serving to supply the actuators (17), preferably between the distributor (30) and the accumulator

(34), an electro-valve (35) implemented automatically by the distributors

(45D) or (45G) as appropriate.

15.- Process for controlling and adjusting the movement of the rear section

(7) of a semi-mounted articulated plow, relative to the front section (5), which sections are connected by means of actuators (17), in the case of a plow according to any one of claims 1 to 14, characterized in that it consists in adjusting, from the tractor, the pressure in said actuating members (17) from a value corresponding to total freedom of movement of said rear section relative to the front section, up to a value which corresponds to a quasi-rigidity of the joint, without achieving complete blocking, placing and keeping the two sections in alignment with one another.

16.- Method according to claim 15, characterized in that it consists in completely releasing the rear section (7), by canceling the pressure in the actuating members (17), by intervention of the operator on the distributor (26) of the tractor, placing said distributor in the lifting position of the plowing bodies which has the effect of sending fluid under pressure to the lifting cylinders (16) disposed on the support carriage.

17.- Method according to any one of claims 15 or 16, characterized in that it consists in aligning the front sections (5) and rear (7), during the operation of lifting the bodies, by introduction of fluid under pressure in the actuators, as soon as the pressure in the lifting cylinders

(16) of the carriage reaches a predetermined threshold.

18.- Method according to any one of claims 15 to 17, characterized in that it consists in raising the rear section (7) by means of the actuating members (17), after turning the plowing bodies, before the lowering of said bodies in the absence of the restrictor (59) according to claim 13, or during the descent of said bodies in the presence of said restrictor.

19.- Method according to claim 18, characterized in that it consists in delaying the descent of the bodies of the rear section (7) so as to reduce the size of the lookout, that is to say to maintain said section in position raised by maintaining the pressure of the hydraulic fluid in the actuators (17) by placing the distributor (26) of the tractor in neutral position.