FR3030183A1 - VEGETABLE CUTTING EQUIPMENT ALLOWING BIDIRECTIONAL ESCAMOTATION OF AN ARM CARRYING A CUTTING TOOL - Google Patents

Abstract

The invention relates to an equipment (2) for cutting plants, intended to be coupled to a self-propelled vehicle (1); equipment comprising: - a frame (4); a carrier block (7) supporting an arm (5) equipped with a cutting tool (6); the carrier block (7) being rotatably mounted on the frame (4) about a vertical axis (A) so as to angularly orient the arm (5); and - a control member (8) capable of driving the pivoting of the carrier block (7) around the first axis (A); the control member (8) having first and second jacks (9, 10). The bodies (11, 12) of the first cylinder (9) and the second cylinder (10) are coaxial and fixed back-to-back; the rod (13) of one of the first and second cylinders (9,10) being hingedly mounted on the frame (4) about a vertical axis (B) and the rod (14) of the other of the first and second cylinders (9,10) being articulated on the carrier block (7) about a vertical axis (C).

Description

TECHNICAL FIELD The invention relates to equipment for cutting plants intended to be coupled to a self-propelled vehicle, of the brushcutter mower type.

Background Art It is known in document FR2913175 a plant cutting equipment coupled to a self-propelled vehicle. The equipment comprises a frame which is equipped with means for fixing to the chassis of the vehicle and a support pivotally mounted on the frame and carrying an arm at the end of which a cutting tool is mounted. The equipment comprises a deformable control structure adapted to cause the pivoting of the support about its pivot axis so as to angularly orient the arm relative to the general axis of progression of the vehicle. The deformable control structure comprises a pivot piece which is articulated on the frame and a pair of hydraulic cylinders including a first jack which has a first end hinged to the pivot piece and a second end articulated on the support and a second jack which has a first end hinged to the pivot piece and a second end hinged to the frame. The deformable control structure is arranged such that when the arm is positioned in a median working position, the first cylinder is in its retracted end position and the second cylinder is in its end position. . Such a deformable control structure is thus able to allow a retraction towards the rear of the arm relative to its median working position when the cutting tool encounters an obstacle during the progression towards the front of the vehicle and to allow a retraction towards the front of the arm relative to its median working position when the cutting tool encounters an obstacle during the progression towards the rear of the vehicle. Such a deformable structure thus allows bidirectional retraction of the arm so as to relieve the arm of the forces exerted on it when the tool hits an obstacle. However, this deformable control structure is complex and cumbersome. Such equipment for cutting plants is not fully satisfactory.

SUMMARY An idea underlying the invention is to propose an equipment for cutting plants, intended to be coupled to a vehicle, comprising a control member for driving in rotation an arm carrying a cutting tool which is simple and space-saving and allows said arm to retract backwards when the cutting tool encounters an obstacle during the forward progression of the vehicle and to retract forward when the tool meets an obstacle when moving backwards. According to one embodiment, the invention provides equipment for cutting plants, intended to be coupled to a self-propelled vehicle; equipment comprising: - a frame; a carrier block supporting an arm which has a distal end equipped with a cutting tool; the carrier block being rotatably mounted on the frame about a first vertical geometric axis so as to angularly orient the arm; and - a control member adapted to cause the pivoting of the carrier block about the first axis; the control member having first and second cylinders each having a body and a rod movable in translation relative to said body between a retracted position towards the inside of the body and an extended position towards the outside of the body; the bodies of the first cylinder and the second cylinder being coaxial and fixed back-to-back; the rod of one of the first and second jacks being hingedly mounted on the frame around a second vertical geometric axis and the rod of the other of the first and second jacks being hingedly mounted on the carrier block around a third vertical geometric axis; the control member being adapted to take at least one working position for which the arm extends into a working position and in which the rod of the first jack is in its retracted position and the rod of the second jack is in its position. extension position so that, in said working position, the rod of the first cylinder is adapted to be moved from its retracted position to its extended position under the effect of a thrust exerted by an obstacle on the cutting tool in a first direction so as to allow a retraction of the arm about the first axis in the first direction and the rod of the second cylinder is adapted to be moved from its extended position to its retracted position under the effect of a thrust exerted by an obstacle on the cutting tool in a second direction opposite to the first direction so as to allow a retraction of the arm around the first axis in the second direction.

Thus, such cutting equipment is equipped with a compact and simple control member that allows the arm to retract in two directions when the cutting tool that it hits an obstacle. According to other advantageous embodiments, such equipment may have one or more of the following features: in its working position, the arm extends in a secant direction to a direction of advance of the vehicle. each of the first and second cylinders is a hydraulic jack which comprises a piston carried by the rod of said jack and separating an internal cylindrical space from the body of said jack in a first chamber and a second chamber so that an increase in the volume of the first chamber is associated with a movement of the rod to its retracted position and an increase in the volume of the second chamber is associated with a displacement of the rod towards its extended position and said equipment comprises a hydraulic control circuit adapted to ensuring control of the first and second cylinders to their working position and allowing a discharge of hydraulic fluid from the first chamber of the first cylinder or the second chamber of the second cylinder when under the effect of a thrust exerted by an obstacle on the cutting tool, the piston of the rod of the first cylinder or the piston of the rod of the second cylinder exerts on the hydraulic fluid a ssion greater than a threshold. the hydraulic control circuit comprises a pump and is connected to the first chamber of the first cylinder and to the second chamber of the second cylinder, the pump and the hydraulic control circuit being able to supply hydraulic fluid to the first chamber of the first cylinder and the second chamber of the second cylinder so as to ensure a positioning of the control member in the working position. - The hydraulic control circuit comprises a pressure limiter connected to the first chamber of the first cylinder and the second chamber of the second cylinder, said pressure limiter being arranged to discharge hydraulic fluid from the first chamber of the first cylinder when under the effect of a thrust exerted by an obstacle on the cutting tool, the piston of the rod of the first cylinder exerts on the hydraulic fluid a pressure greater than a threshold and discharge hydraulic fluid from the second chamber of the second cylinder when under the the effect of a thrust exerted by an obstacle on the cutting tool, the piston of the rod of the second cylinder exerts on the hydraulic fluid a pressure greater than said threshold. The hydraulic control circuit may also comprise two pressure limiters which are respectively connected to the first chamber of the first cylinder and the second chamber of the second cylinder. the hydraulic control circuit is equipped with a hydraulic accumulator which is connected to the first chamber of the first cylinder and the second chamber of the second cylinder so that said hydraulic accumulator is able to be loaded with hydraulic fluid in order to evacuate the hydraulic fluid of the first chamber of the first cylinder or second chamber of the second cylinder when under the effect of a thrust exerted by an obstacle on the cutting tool, the piston of the rod of the first cylinder or the piston of the rod of the second cylinder exerts on the hydraulic fluid a pressure greater than a threshold of supply pressure of the hydraulic accumulator and is adapted to return the hydraulic fluid stored to the first chamber of the first cylinder or the second chamber of the second cylinder when the pressure of the hydraulic fluid becomes lower than the supply pressure threshold of the hydraulic accumulator. The hydraulic control circuit may also comprise two hydraulic accumulators which are respectively connected to the first chamber of the first cylinder and the second chamber of the second cylinder. the internal cylindrical space of the first jack has a diameter which is greater than the diameter of the internal cylindrical space of the second jack and which is adapted so that the retraction of the arm in one or other of the directions occurs from an identical effort threshold. according to other embodiments, the two cylinders can also be electric cylinders. - The control member is adapted to take a middle position in which the first axis A, the second axis B and the third axis C are aligned in a median vertical plane and the control member is able to take two work positions distinct respectively corresponding to a positioning of the third axis (C) on either side of said median vertical plane and in which the rod of the first cylinder is in its retracted position and the rod of the second cylinder is in its extended position. in the middle position of the control member for which the first axis A, the second axis B and the third axis C are aligned, the third axis C lies between the first and second axes A, B. - the stroke of the rod of the first cylinder between its retracted position and its extended position is less than the stroke of the rod of the second cylinder between its retracted position and its extended position. the arm extends in a plane and the first and third axes A and C are substantially aligned in the plane of the arm. - The arm is an articulated arm movable between a folded position and an extended position. - The equipment comprises a guide rail for attachment to the self-propelled vehicle transversely to the direction of advance of the self-propelled vehicle and the frame is slidably mounted on said guide rail. According to one embodiment, the invention also provides a self-propelled vehicle comprising equipment for the aforementioned plant cutting. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood, and other objects, details, features and advantages thereof will become more apparent in the following description of several particular embodiments of the invention, given only in connection with the invention. illustrative and non-limiting, with reference to the accompanying drawings. - Figure 1 illustrates a self-propelled vehicle equipped with a plant cutting equipment. FIG. 2 is a schematic top view of the plant cutting equipment of FIG. 1 in which the arm carrying the cutting tool is disposed in a working position in which the cutting tool is directed to the right of the vehicle. FIG. 3 is a schematic view from above of the plant cutting equipment in which the arm retracts backwards from a working position because of the encounter of the cutting tool with a obstacle. FIG. 4 is a schematic top view of the plant cutting equipment in which the arm is in the transport position. FIG. 5 is a schematic view from above of the plant cutting equipment illustrating the position of the arm during its stroke between a first working position in which the cutting tool is disposed to the right of the vehicle and a second working position in which the cutting tool is disposed to the left of the vehicle. - Figure 6 is a schematic top view of the plant cutting equipment in which the arm carrying the cutting tool is disposed in its second working position in which the cutting tool is disposed to the left of the vehicle. Figure 7 is a schematic sectional view of the controller. - Figure 8 schematically illustrates a hydraulic control circuit according to a first embodiment when the control member is in a first working position. FIG. 9 schematically illustrates the hydraulic control circuit of FIG. 8 when the control member is in its median position between its first and second working positions. - Figure 10 schematically illustrates the hydraulic control circuit of Figure 8 when the control member is in a second working position. - Figure 11 schematically illustrates a hydraulic control circuit according to a second embodiment. - Figure 12 schematically illustrates a hydraulic control circuit according to a third embodiment. FIG. 13 schematically illustrates a hydraulic control circuit according to a fourth embodiment. DETAILED DESCRIPTION OF EMBODIMENTS FIG. 1 shows a vehicle 1 carrying equipment 2 for cutting plants. The plant cutting equipment 2 comprises a guide rail 35 which is fixed on the chassis of the vehicle 1 and extends transversely to the direction of advance of the vehicle. The equipment 2 also comprises a frame 4 slidably mounted on the guide rail 3 in a direction transverse to the direction of advance of the vehicle. Motor means, not shown in detail, can control the displacement of the frame 4 along the guide rail 3. The equipment 2 is here coupled to the front of the vehicle 1. However, according to another embodiment not shown, the equipment 2 is coupled to the rear of the vehicle 1. The equipment comprises an arm 5 which is provided at its distal end with a cutting tool 6 adapted for cutting plants. The arm 5 is articulated on a carrier block 7 and has several articulated sections one after the other 15. One or more cylinders, not shown, are assigned to the displacement of said articulated sections and thus allow to deploy the arm 5 between a folded position and an extended position. A carrier block 7 is hingedly mounted on the frame 4 about a vertical geometric axis A and thus makes it possible to orient the arm 5 with respect to the direction of advance of the vehicle 1. Thus, the arm 5 can be positioned in a first working position, shown in Figures 1 and 2, in which it extends orthogonally to the direction of advance of the vehicle 1 and its distal end is directed to the right of the vehicle 1 so as to allow the cutting of plants located on the road shoulder disposed on the right of the vehicle 1. In this first working position, the frame 4 is advantageously positioned at the right end of the guide rail 3. The arm 5 can also be positioned in a position transport, also called road position, shown in Figure 4, wherein the distal end of the arm 5 is directed, relative to its working position, towards the vehicle chassis 1 d e so as to reduce the clutter of the equipment 2 when not in use. Advantageously, as shown in Figure 4, the frame 4 is positioned at the right end of the guide rail 3 when the arm 5 is positioned in a transport position, in which its distal end is directed to the left of the vehicle 1, so that neither the arm 5 nor the cutting tool 6 protrudes from one side or the other of the vehicle 1. Finally, according to an advantageous embodiment, the arm 5 is also capable of taking a second working position shown in Figure 6 wherein it extends orthogonally to the direction of advance and its distal end bearing the cutting tool 6 is directed to the left of the vehicle 1 so as to allow the cutting of plants located on the road shoulder disposed to the left of the vehicle 1. In this second working position, the frame 4 is advantageously positioned at the left end of the guide rail 3. With reference to FIGS. 1 to 6, it is observed that a control member 8 adapted to pivot the carrier block 7 about its vertical axis of rotation A so as to angularly orient the arm 5 relative to the direction of advance of the vehicle 1 and to arrange the arm in one of the aforementioned positions. The control member 8 comprises a pair of jacks 9, 10. Each jack 9, 10 comprises a body 11, 12 and a rod 13, 14 movable in translation inside the body 11, 12 between a retracted position to the interior of the body 11, 12 and an extension position outside the body 11, 12. The bodies 11, 12 of the cylinders 9, 10 are mounted back-to-back coaxially. In other words, the cylinders 9, 10 are oriented in the opposite direction and secured to one another by the bottom of their body 11, 12 so that the extension movements of the rods 13, 14 of their retracted position to their extended position are oriented in opposite directions. Furthermore, the rod 13 of the first jack 9 is hingedly mounted on the frame 4 about a vertical geometric axis B and the rod 14 of the second jack 10 is hingedly mounted on the carrier block 7 about a vertical geometric axis C Thus, the movement of one and / or the other of the rods 13, 14 between their retracted position and their extended position causes the carrier block 7 to pivot relative to the frame 4. The strokes of the cylinders 9, 10 as well as the relative positions of the articulation axis A of the carrier block 7 on the frame, of the hinge axis B of the rod 13 of the first jack 9 on the frame 4 and the hinge pin C of the rod 14 of the second cylinder 10 on the carrier block 7 are arranged such that the control member 8 can take a position shown in Figure 5 in which the three hinge pins A, B, C are aligned according to a median plane. Thus, it is possible by an external force to pass the hinge axis C on either side of the median plane passing through the axes A, B so as to move the arm 5 of its first working position, shown in FIG. 1, in which the cutting tool 6 is positioned to the right of the vehicle 1 towards its second working position, shown in FIG. 6, in which the cutting tool 6 is positioned on the left side of the vehicle or Conversely. Advantageously, as represented in particular in FIG. 5, the median plane passing through the axes A and B extends substantially parallel to the longitudinal direction of the vehicle 1, that is to say forms an angle with the longitudinal direction of the vehicle. vehicle 1 less than 200. The hinge axis B is positioned relative to the hinge axis A to the vehicle 1. In addition, the hinge axis C is located, when the control member 8 is in its median position, between the hinge axis A and the hinge axis B. Such an arrangement of the control member 8 allows a reversal of the arm between its two working positions without the arm 5 and / or the cutting tool 6 will be passed over the vehicle 1. In other words, when the equipment 2 is coupled to the front of the vehicle 1, as shown in Figure 1, the arm 5 extends towards the front of the vehicle 1 during a pivoting of the carrier block 7 to move the b flush 5 between its two working positions while, when the equipment 2 is coupled to the rear of the vehicle 1, the arm 5 extends towards the rear of the vehicle 1 during its movement between its two working position. Such an arrangement also makes it possible to ensure greater compactness of the control member 8. Furthermore, the hinge axis A of the carrier block 7 on the frame 4 and the hinge axis C of the second jack 10 on the carrier block 7 are substantially aligned with the plane of the arm 5 so as to provide substantially symmetry of the two working positions. When the arm 5 is in one of its working positions, shown in Figures 2 and 6, the first cylinder 9 is, in the end stroke, in its retracted position while the second cylinder 10 is at the end of the race in its extended position. Thus, such a configuration of the control member 8 in its working position is likely to allow a retraction forward or rearward of the arm 5 relative to its working position when the cutting tool 6 and / or the arm 5 hits an obstacle 15.

Indeed, as shown in Figure 3, when the arm 5 is in one of its working positions and the cutting tool 6 encounters an obstacle 15 during the operation in the forward direction of the vehicle 1, the rod 13 of the first jack 9 is able to move from its retracted position to its extended position under the effect of the thrust exerted by the obstacle 15 on the cutting tool 6 so as to allow a retraction of the arm 5 towards the 'back. Conversely, when the cutting tool 6 encounters an obstacle during the reverse operation of the vehicle 1, the rod 14 of the second cylinder 10 is able to move towards its retracted position under the effect of the thrust exerted by the vehicle. obstacle 15 on the cutting tool 6 so as to allow retraction of the arm 5 forward. When the arm 5 is in its transport position, as shown in Figure 4, the first cylinder 9 and the second cylinder 10 are each end of stroke in their extended position.

The angle of displacement of the arm 5 between its median position and its working position is greater than the angle of movement of the arm 5 between its working position and its transport position, the second cylinder 10 has a greater stroke than that of the first cylinder 9. As shown in more detail in Figure 7, the rod 13, 14 of each cylinder 9, 10 carries a piston 16, 17 movable in translation within the internal cylindrical space of the body 11 , 12 of the cylinder 9, 10. Each piston 16, 17 thus separates the cylindrical space of the body 11, 12 of the cylinder 9, 10 associated in two chambers 18, 19, 20, 21: one, said first chamber 18, 19, the volume increase is associated with a displacement of the rod 13, 14 to its retracted position and the other, said second chamber 20, 21, whose volume increase is associated with a displacement of the rod 13 , 14 to its extended position. Each of chambers 18, 19, 20, 21 is connected to a hydraulic control circuit. In relation with FIGS. 8, 9 and 10, a hydraulic control circuit is described, according to a first embodiment, capable of controlling the control member 8 and allowing the arm 5 to be retracted. The hydraulic control circuit comprises a reservoir 22 of hydraulic fluid, a distributor 23, a pump 24 and a pressure limiter 25.

The hydraulic fluid reservoir 22 is connected to the inlet of the distributor 23 via a pipe 26 equipped with the pump 24. The first chamber 18 of the first cylinder 9 and the second chamber 21 of the second cylinder 10 are connected. one to the other by a pipe 27 which is connected to the outlet of the distributor 23. The second chamber 20 of the first cylinder 9 and the first chamber 19 of the second cylinder 10 are connected via a pipe 28 which is directly connected to the reservoir 22. The dispenser 23 is adapted to take a feeding position, not shown, in which the distributor 23 communicates the pipe 26 and the pipe 27 so as to supply the chambers 18, 21 with hydraulic fluid until the rod 13 of the first cylinder 9 reaches its retracted position and the rod 14 of the second cylinder 10 reaches its extended position so as to position the control member 8 in its working position. When the control member 8 is in one of its working positions, as shown in FIGS. 8 and 10, the distributor 23 is brought into its neutral position in which the hydraulic communication between the reservoir 22 and the connected pipe 27 at the first chamber 18 of the first cylinder 9 and the second chamber 21 of the second cylinder 10 is interrupted. The chambers 18, 21 are then connected to the tank 22 only through the pressure limiter 25, also called safety valve. The pressure limiter 25 thus allows an evacuation of the hydraulic fluid from the first chamber 18 of the first cylinder 9 or the second chamber 21 of the second cylinder 10 when the distributor 23 is in its neutral position and under the effect of a thrust. caused by an obstacle on the cutting tool, the piston 16, 17 of the rod 13, 14 of the first cylinder 9 or the second cylinder 10 exerts on the hydraulic fluid a pressure greater than a pressure threshold of the pressure limiter 25. The pressure limiter 25 thus allows the retraction of the arm 5 to be retracted forwardly or rearwardly. It may be observed that by choosing a pressure threshold of the appropriate pressure limiter 25, the sensitivity of the arm 5 is adjusted. to retraction. In an advantageous embodiment, the internal cylindrical space of the first cylinder 9 has a diameter which is slightly greater than that of the internal cylindrical space of the second cylinder 10 and the diameters of the internal cylindrical spaces of the cylinders 9, 10 are determined from such that the retraction of the arm 5 occurs from an identical effort threshold in one direction or the other. The thrust surface of the piston 16 or 17 located in the first chamber 18 or 19 of each cylinder 9, 10 being smaller than the corresponding thrust surface located in the second chamber 20 or 21, it is therefore necessary to provide a first cylinder 9 having a diameter slightly greater than that of the second cylinder 10 to compensate for this imbalance. After a retraction of the arm 5, the distributor 23 is controlled so as to return to its feeding position and reposition the arm 5 in the working position he has just left. Furthermore, the distributor 23 is also adapted to assume a draining position, shown in FIG. 9, in which the two chambers 18, 19, 20, 21 of each of the cylinders 9, 10 are connected to the tank 22. This emptying position allows, by an external force, to pass the central position or dead point of the control member 8 in which the three axes A, B, C are aligned in order to pass the hinge axis C of share or other of the median plane passing through the axes A and B and allow a reversal of the arm 5 between its two working positions. Figure 11 shows schematically a control hydraulic circuit according to a second embodiment. This hydraulic control circuit differs from the hydraulic control circuit of Figures 8 to 10 in that it further comprises a hydraulic accumulator 29 which is connected directly to the first chamber 18 of the first cylinder 9 and the second chamber 21 of the second cylinder 10. Such a hydraulic accumulator 29 comprises a reservoir equipped with a variable volume chamber which is able, on the one hand, to be filled with hydraulic fluid when the pressure of the hydraulic fluid is greater than a filling pressure threshold of in order to store hydraulic energy and, on the other hand, to empty when the pressure of the hydraulic fluid becomes lower than said filling pressure threshold so as to restore the accumulated hydraulic energy. Thus, the variable volume chamber of the hydraulic accumulator 29 is loaded with hydraulic fluid to drive hydraulic fluid from the first chamber 18 of the first cylinder 9 or the second chamber 21 of the second cylinder 10 when under the effect of A thrust exerted by an obstacle 15 on the cutting tool 6 the pressure of the hydraulic fluid becomes greater than the filling pressure threshold of the hydraulic accumulator 29 so as to allow a retraction of the arm 5. When the cutting tool 6 has escaped the obstacle 15 under the effect of the retraction of the arm 5 and is no longer in contact with the obstacle 15, the variable volume chamber of the hydraulic accumulator 29 empties and returns the fluid to the chambers 18, 21 so as to reposition the control member 8 in its working position. Such a hydraulic accumulator 29 thus makes it possible to perform an elastic return of the arm 5 towards its working position after a retraction. In this embodiment, the pressure limiter 25 advantageously has a pressure threshold greater than the filling pressure threshold of the hydraulic accumulator 29. In another embodiment, not illustrated, the hydraulic control circuit comprises a hydraulic accumulator 29 as described above but does not include a pressure limiter 25. Figure 12 schematically shows a hydraulic control circuit according to a third embodiment. In this embodiment, the hydraulic control circuit comprises a distributor 31 which allows both the control of the control member 8 and the control of another double-acting cylinder 30 of the equipment, such as a cylinder ensuring the deployment of the articulated arm 5. This embodiment thus saves a distributor. The distributor 31 is able to take a feed position, not shown, in which it puts in communication the pipe 26 equipped with the pump 24 and connected to the reservoir 22 with a pipe 32 connected to one of the chambers of the jack 30 It thus makes it possible to supply the chamber of the jack 30 until the rod of said jack 30 reaches one of its end-of-stroke positions. The pipe 32 is connected to the pipe 27 connected to the first chamber 18 of the first cylinder 9 as well as to the second chamber 21 of the second cylinder 30 10 via a non-return valve 33. Thus, when the chamber the cylinder 30 is filled, the hydraulic fluid passes through the check valve 33 so as to supply said chambers 18, 21 with hydraulic fluid until the rod 13 of the first cylinder 9 reaches its retracted position and the rod 14 of the second cylinder 14 reaches its extended position and that the control member 8 is thus positioned in its working position. On the other hand, the second chamber 20 of the first cylinder 9 is connected to a three-way valve 34. In a normal position, illustrated in FIG. 12, the distributor 34 connects the second chamber 20 of the first cylinder 9 to a pipe 28 which is directly connected to the reservoir 22. In a transport position, the distributor 34 makes it possible to connect the first chamber 18 and the second chamber 20 of the first cylinder 9. The thrust surface being greater on the side of the second chamber 20, the position of transport of the distributor 34 causes the rod 13 of the first cylinder 9 to move towards its extended position and consequently a positioning of the arm 5 in its transport position, as illustrated in FIG. 4. In the hydraulic circuit of FIG. 13, the hydraulic control circuit is equipped with a double-acting distributor 35 which is adapted to take a first feed position in which it will ccorde the tank to the first chamber 19 of the second cylinder 10, a second supply position in which it connects the tank 23 to the second chamber 21 of the second cylinder 10 and a neutral position in which the hydraulic communication between the tank 22 and the rooms 19, 21 is interrupted. The distributor 35 is therefore able to control the movement of the arm 5 between its two working positions. Furthermore, the pipe 36 leading to the second chamber 21 of the second cylinder 10 is connected to the first chamber 18 of the first cylinder 9, the pressure limiter 25, the hydraulic accumulator 29 and the three-way valve 34. The operation of the The hydraulic control circuit for controlling the first cylinder 9 is in this embodiment identical to that of the embodiment of FIG. 12. Although the invention has been described in connection with several particular embodiments, it is well It is obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described and their combinations if they fall within the scope of the invention. In particular, if several hydraulic control circuits have been described above by way of example, other hydraulic control circuits are also conceivable.

The use of the verb "to include", "to understand" or "to include" and its conjugated forms does not exclude the presence of other elements or steps other than those set out in a claim. The use of the indefinite article "a" or "an" for an element or a step does not exclude, unless otherwise stated, the presence of a plurality of such elements or steps. In the claims, any reference sign in parentheses can not be interpreted as a limitation of the claim.

Claims (5)

REVENDICATIONS1. Equipment (2) for cutting plants, intended to be coupled to a self-propelled vehicle (1); equipment comprising: - a frame (4); - a carrier block (7) supporting an arm (5) which has a distal end equipped with a cutting tool (6); the carrier block (7) being rotatably mounted on the frame (4) around a first vertical geometric axis (A) so as to angularly orient the arm (5); and - a control member (8) capable of driving the pivoting of the carrier block (7) around the first axis (A); the control member (8) comprising a first and a second cylinder (9, 10) each having a body (11, 12) and a movable rod (13, 14) in translation relative to said body (11, 12) between a retracted position towards the inside of the body (11, 12) and an outward extension position of the body (11, 12); The bodies (11, 12) of the first cylinder (9) and the second cylinder (10) being coaxial and fixed back-to-back; the rod (13) of one of the first and second cylinders (9,10) being hingedly mounted on the frame (4) around a second vertical geometric axis (B) and the rod (14) of the other first and second cylinders (9,10) being hingedly mounted on the carrier block (7) about a third vertical geometric axis (C); The control member being adapted to take at least one working position for which the arm (5) extends into a working position and in which the rod (13) of the first jack (9) is in its retracted position and the rod (14) of the second jack (10) is in its extended position so that, in said working position, the rod (13) of the first jack (9) is able to be moved from its position 25 retracted towards its extended position under the effect of a thrust exerted by an obstacle (15) on the cutting tool (6) in a first direction so as to allow a retraction of the arm (5) around the first axis (A) in the first direction and the rod (14) of the second ram (10) is adapted to be moved from its extended position to its retracted position under the effect of a thrust exerted by an obstacle (15). on the cutting tool (6) in a second direction opposite to the first direction so as to allow an esc arm tilting (5) about the first axis (A) in the second direction. 2. Equipment (2) according to claim 1, wherein each of the first and second cylinders (9, 10) is a hydraulic cylinder which comprises a piston (16, 17) carried by the rod (13, 14) of said cylinder (9). 10) and separating an internal cylindrical space of the body (11, 12) of said cylinder (9, 10) into a first chamber (18, 19) and a second chamber (20, 21) so that an increase in the volume of the first chamber is associated (18, 19) with a displacement of the rod (13, 14) towards its retracted position and that an increase in the volume of the second chamber (20, 21) is associated with a movement of the rod (13,14) to its extended position and wherein said equipment (2) comprises a hydraulic control circuit adapted to provide control of the first and second cylinders (9, 10) to their working position and to allow evacuation of hydraulic fluid of the first chamber (18) of the first cylinder (9) or the second chamber (21) of the second cylinder (10) under the effect of a thrust exerted by an obstacle (15) on the cutting tool (5), the piston (16) of the rod (13) of the first cylinder (9) or the piston (17) of the rod (14) of the second cylinder (10) exerts on the hydraulic fluid a pressure greater than a threshold. 3. Equipment (2) according to claim 2, wherein the hydraulic control circuit comprises a pressure limiter (25) connected to the first chamber (18) of the first cylinder (9) and the second chamber (21) of the second cylinder (10), said pressure limiter (25) being arranged to discharge hydraulic fluid from the first chamber (18) of the first cylinder (9) when under the effect of a thrust exerted by an obstacle on the tool of cut (6), the piston (16) of the rod (13) of the first cylinder (9) exerts on the hydraulic fluid a pressure greater than a threshold and discharge hydraulic fluid from the second chamber (21) of the second cylinder (10). ) when under the effect of a thrust exerted by an obstacle on the cutting tool (5), the piston (17) of the rod (14) of the second cylinder (10) exerts on the hydraulic fluid a pressure greater than the said threshold. 4. Equipment (2) according to claim 2 or 3, wherein the hydraulic control circuit is equipped with a hydraulic accumulator (29) which is connected to the first chamber (18) of the first cylinder (9) and the second chamber (20) of the second cylinder (10) such that said hydraulic accumulator (29) is adapted to be loaded with hydraulic fluid in order to evacuate hydraulic fluid from the first chamber (18) of the first cylinder (9) or from the second chamber (21) of the second cylinder (10) under the effect of a thrust exerted by an obstacle (15) on the cutting tool (5), the piston (16) of the rod (13) of the first cylinder (9) or the piston (17) of the rod (14) of the second cylinder (10) exerts on the hydraulic fluid a pressure greater than a supply pressure threshold of the hydraulic accumulator (29) and is suitable returning the stored hydraulic fluid to the first chamber (18) of the first cylinder (9) or the second chamber (21) of the second cylinder (10) lo when the pressure of the hydraulic fluid returns to below the supply pressure threshold of the hydraulic accumulator (29). 5. Equipment (2) according to any one of claims 2 to 4, wherein the internal cylindrical space of the first cylinder (9) has a diameter which is greater than the diameter of the internal cylindrical space of the second cylinder (10). ) and which is adapted so that the retraction of the arm (5) in one or other of the directions occurs from an identical effort threshold. a _mulpeMci ') --'- n any claim e D, wherein the control member (8) is adapted to take a middle position 15 in which the first axis (A), the second axis (B ) and the third axis (C) are aligned in a median vertical plane and in which the control member (8) is adapted to take two distinct working positions respectively corresponding to a positioning of the third axis (C) on the left and right. other of said median vertical plane and in which the rod (13) of the first jack (9) is in its retracted position and the rod (14) of the second jack (14) is in its extended position. 7. Equipment (2) according to claim 6, wherein in the central position of the control member (8) for which the first axis (A), the second axis (B) and the third axis (C) are aligned, the third axis (C) is between the first and second axes (A, B). 8. Equipment (2) according to any one of claims 1 to 7, wherein the stroke of the rod (13) of the first jack (9) between its retracted position and its extended position is less than the stroke of the rod (14) of the second cylinder (10) between its retracted position and its extended position. 9. Equipment (2) according to any one of claims 1 to 8, wherein the arm (5) extends in a plane and wherein the first and third axes (A, C) are substantially aligned in the arm plane (5) .10. Equipment according to any one of claims 1 to 9, wherein the arm (5) is an articulated arm movable between a folded position and an extended position. 11. Equipment according to any one of claims 1 to 10, 5 comprising a guide rail (3) intended to be fixed to the self-propelled vehicle (1) transversely to the direction of advance of the self-propelled vehicle (1) and in which the frame (4) is slidably mounted on said guide rail (3). 12. Self-propelled vehicle (1) equipped with equipment (2) for cutting plants according to any one of claims 1 to 11. 10