ARRANGEMENT FOR A SPRAY BAR WITH A DEVICE FOR MITIGATING THE WHIP EFFECT

Description

TECHNICAL FIELD

[0001] The invention relates to a spray boom assembly, a spray boom for an agricultural spraying system comprising such an assembly, as well as an agricultural spraying system for agricultural machinery comprising such a spray boom. STATE OF THE PRIOR ART

[0002] It is known to implement agricultural spraying systems comprising a spray boom supporting nozzles through which a treatment liquid, such as a plant protection product or liquid fertilizer, is sprayed generally vertically downwards onto plants to be treated in a field.

[0003] In large-scale cultivation, the spray boom comprises a central frame, as well as two main arms which carry the nozzles and which are each mounted on the frame, on an opposite side of the frame in a transverse direction to a longitudinal direction oriented from back to front in the direction of advance of the agricultural sprayer.

[0004] In a spraying configuration, these main arms extend generally transversely on each side of the frame. They can also be extended by secondary arms also carrying nozzles and themselves extending transversely in this spraying configuration. The spray boom can thus have a transverse dimension or span ranging from 7 to more than 50 m in this spraying configuration.

[0005] A large area of ​​the field of plants to be treated can thus be sprayed by passing the spray boom, which represents a significant time saving for the farmer.

[0006] However, such scales pose some difficulties.

[0007] In particular, a whipping phenomenon of the spray boom appears in a straight line during sudden accelerations or decelerations of the agricultural spraying system, when exiting bends or on chaotic terrain. This whipping phenomenon results in oscillations, particularly of the main arms relative to the central frame. This whipping phenomenon is very harmful to the spray boom from the point of view of its mechanical resistance.

[0008] FR 2 816 805 A1 discloses a spray boom comprising an anti-vibration device, EP 1 683 414 B1 discloses an anti-whipping device deposited outside a connection between an arm of the spray boom and the central frame. STATEMENT OF THE INVENTION

[0009] In order to overcome this drawback, the present invention relates to an assembly for a spray boom of an agricultural spraying system comprising a first structural element, a second structural element, one of the first structural element and the second structural element comprising a sheath extending around a first extension axis, the other of the first structural element and the second structural element comprising a shaft extending along a second extension axis, the shaft being surrounded by the sheath and pivotally mounted in the sheath around the second extension axis, as well as an anti-whipping device designed to dampen whipping of the first structural element and the second structural element relative to each other, the anti-whipping device being mounted inside the sheath, between the shaft and the sheath.

[0010] According to embodiment variants which can be taken together or separately:the anti-whip device is designed to passively dampen the whipping of the first structural element and the second structural element relative to each other; the anti-whip device comprises at least one damping pad, the or each damping pad having a generally tubular shape extending around the first and second extension axes, the or each damping pad surrounding the shaft and being itself surrounded by the sleeve; the anti-whip device comprises a ball joint mounted between the sleeve and the shaft, the shaft thus being articulated inside the sleeve; the anti-whip device comprises a guide member having a generally tubular shape extending around the second extension axis, the guide member surrounding the shaft and being itself surrounded by the sleeve;the anti-whip device comprises a ball joint mounted between the guide member and the sheath, so as to articulate the shaft inside the sheath via the guide member; the shaft is mounted so as to pivot freely in the guide member around the second extension axis; the guide member is mounted so as to pivot freely relative to the sheath around a pivot axis, arranged perpendicular to the first extension axis, and pivotally secured relative to the sheath around axes perpendicular to the pivot axis, the guide member thus forming a universal joint;the anti-whip device comprises two damping sub-assemblies arranged at a distance from each other along the first extension axis, each damping sub-assembly comprising at least one damping pad, each damping pad having a generally tubular shape extending around the first and second extension axes, each damping pad further surrounding the shaft and being itself surrounded by the sheath.;

[0011] The invention also relates to a spray boom for an agricultural spraying system comprising a central frame, at least one main arm mounted on the central frame and at least one assembly as previously described.

[0012] According to embodiment variants which can be taken together or separately: the boom comprises at least one secondary arm mounted in the extension of the or one of the main arms, said main arm and one or more secondary arms succeeding one another from the central frame to a free end of the spray boom; the first structural element of at least one assembly is formed by the central frame and the second structural element of the at least one assembly is formed by the or one of the main arms; the first structural element of at least one assembly is formed by the or one of the main arms and the second structural element of the at least one assembly is formed by the secondary arm mounted on said main arm; the first structural element of at least one assembly is formed by one of the secondary arms, while the second structural element of the at least one assembly is formed by another of the secondary arms which is mounted on one of the secondary arms.The invention also relates to an agricultural spraying system (100) for agricultural machinery comprising a spray boom (10) as previously described. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Other aspects, aims, advantages and characteristics of the invention will appear better on reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the appended drawings in which: [ Fig. 1 ] is a schematic front view of an agricultural spraying system comprising a spray boom according to one embodiment of the invention; [ Fig.2 ] is a detail view of a spray boom according to one embodiment; [ Fig.3 ] is a sectional view of the spray boom shown in figure 2 , following a generally longitudinal and vertical cutting plane; [ Fig.4] is a sectional view of a spray boom according to another embodiment, along a generally longitudinal and vertical sectional plane; [ Fig.5 ] is a sectional view of a spray boom according to another embodiment, along a generally longitudinal and vertical sectional plane; [ Fig.6 ] is a sectional view of a spray boom according to another embodiment, along a generally longitudinal and vertical sectional plane. DETAILED DESCRIPTION

[0014] There figure 1 shows an agricultural spraying system 100, in particular for large-scale cultivation, such as cereal cultivation, comprising a spray boom 10 intended to spray a treatment liquid, such as phytosanitary product or liquid fertilizer, on plants to be treated in a field, according to one embodiment of the invention.

[0015] The spraying system 100 is in contact with the soil of the field of plants to be treated, in particular via wheels 101 allowing it to move.

[0016] The spraying system 100 is for example self-propelled and therefore forms in itself an agricultural machine, such as a tractor. Alternatively (not shown), the spraying system 100 is intended to be carried by the agricultural machine. Still alternatively (not shown), the spraying system 100 is intended to be towed by an agricultural machine.

[0017] An orthogonal reference system is adopted, without limitation, comprising a longitudinal direction X towards the front in the direction of advancement of the agricultural machine, a transverse direction Y towards the left and a vertical direction Z towards the top. The longitudinal and transverse directions are horizontal, generally parallel to the ground of the field of plants to be treated.

[0018] The spray bar 10 comprises at least one assembly itself comprising a first structural element 10.1, a second structural element 10.2, as well as an anti-whipping device 10.3.

[0019] The spray bar 10 may further comprise a central frame 11 and at least one main arm 12 mounted on the central frame 11. The spray bar 10 comprises, for example, two main arms 12 each mounted on the central frame 11 on an opposite side of said central frame 11 in the transverse direction Y. The spray bar 10 is produced symmetrically with respect to a longitudinal and vertical plane of symmetry PS centered on the central frame 11. Also, only one of the sides of this plane of symmetry PS will be described below.

[0020] The spray bar 10 may also comprise at least one secondary arm 13 mounted in the extension of the main arm 12, the main arm 12 and one or more secondary arms 13 thus following one another from the central frame 11 to a free end of the spray bar 10. The free end of the spray bar 10 is then carried by the secondary arm 13 which is the last from the central frame 11.

[0021] The first structural element 10.1 of at least one assembly is for example formed by the central frame 11, while the second structural element 10.2 of the at least one assembly is formed by the main arm 12.

[0022] The first structural element 10.1 of at least one assembly may also be formed by the main arm 12, while the second structural element 10.2 of the at least one assembly is formed by the secondary arm 13 mounted on the main arm 12.

[0023] The first structural element 10.1 of at least one assembly may still be formed by one of the secondary arms 13, while the second structural element 10.2 of the at least one assembly is formed by another of the secondary arms 13 which is mounted on one of the secondary arms 13.

[0024] In the remainder of the description, only an assembly in which the first structural element 10.1 is formed by the central frame 11 and the second structural element 10.2 is formed by the main arm 12 will be described in detail. The following teachings, however, apply mutatis mutandis to the other assemblies.

[0025] One of the central frame 11 and the main arm 12 comprises a sheath 14 extending around a first extension axis 15, while the other of the central frame 11 and the main arm 12 comprises a shaft 16 which extends along a second extension axis 17, which is surrounded by the sheath 14 and which is pivotally mounted in the sheath 14 around the second extension axis 17. The central frame 11 and the main arm 12 are thus pivotally mounted relative to each other around the second extension axis 17. The shaft 16 passes for example through the sheath 14 from one side to the other. On the figures 2 to 6, without this being limiting, the sheath 14 is carried by the main arm 12, while the shaft 16 is carried by the central frame 11. The anti-whip device 10.3 is designed to dampen the whipping of the main arm 12 relative to the central frame 11. By "whipping" is meant oscillations or a back-and-forth movement of the main arm 12 relative to the central frame 11, and therefore of the shaft 16 and the sheath 14 relative to each other. The shaft 16 and the sheath 14 oscillate around a rest position in which the shaft 16 and the sheath 14 are coaxial, the first and second extension axes 15, 17 being merged. These oscillations occur, for example, in a straight line when the agricultural spraying system 100 accelerates or brakes suddenly, when exiting a bend or on bumpy terrain.

[0026] According to the invention, the anti-whip device 10.3 is further mounted inside the sheath 14, between the shaft 16 and the sheath 14. The anti-whip device 10.3 is thus mounted integrally or entirely inside the sheath 14. The anti-whip device 10.3 is surrounded by the sheath 14 and surrounds the shaft 16. In other words, the anti-whip device 10.3 is interposed between the shaft 16 and the sheath 14 in a first radial direction, taken relative to the first extension axis 15. In this way, the anti-whip device 10.3 is hidden inside the sheath 14.This makes it possible in particular to limit the size of the spray bar 10, to limit the number of parts necessary to manufacture the spray bar 10, to reduce the mass of the spray bar 10 and / or to facilitate the design of other aspects of the spray bar 10, such as the pivoting control of the main arm 12 relative to the central frame 11. This also makes it possible to act as closely as possible on the mechanical forces transmitted between the main arm 12 and the central frame 11, and therefore to reduce the associated mechanical stresses.

[0027] The anti-whip device 10.3 is for example designed to passively dampen the whipping of the main arm 12 relative to the central frame 11. “Passively” means that the damping is carried out without the input of external energy. “External energy” means any energy other than that induced or supplied by the movement to be damped, here the whipping of the main arm 12 relative to the central frame 11. Conversely, active damping requires an input of external energy. This is for example electrical, hydraulic or even pneumatic energy in the case of damping carried out by one or more cylinders.

[0028] In this way, the anti-whip device 10.3 does not require any control or piloting to dampen the whipping of the main arm 12 relative to the central frame 11, thus simplifying its design.

[0029] For this, the anti-whip device 10.3 comprises for example at least one damping pad 18 and / or a ball joint 19 and / or a guide member 20.

[0030] The or each damping pad 18 has a generally tubular shape and extends around the first and second extension axes 15, 17. The or each damping pad 18 surrounds the shaft 16 and is itself surrounded by the sleeve 14. The or each damping pad 18 is interposed in the first radial direction between the sleeve 14 and the shaft 16. The shaft 16 passes, for example, right through the or each damping pad 18.

[0031] The or each damping pad 18 thus makes it possible to dampen the whipping or even the oscillations of the shaft 16 and the sheath 14 relative to each other.

[0032] The or each damping pad 18 can be mounted so as to pivot freely relative to the sleeve 14 around the first extension axis 15, in particular by means of a mounting with clearance. Alternatively, the or each damping pad 18 is mounted so as to pivot securely in the sleeve 14 around the first extension axis 15, in particular by means of a tight mounting.

[0033] The or each damping pad 18 can also be mounted so as to pivot freely relative to the shaft 16 around the second extension axis 17, in particular by means of a mounting with clearance. Alternatively, the shaft 16 is mounted so as to pivot securely in the damping pad(s) 18 around the second extension axis 17, in particular by means of a tight mounting.

[0034] The anti-whiplash device 10.3 comprises, for example, two damping sub-assemblies each comprising at least one damping pad 18, the two damping sub-assemblies being arranged at a distance from or being spaced apart from each other along the first extension axis 15. The damping sub-assemblies thus define a free space 21 between them.

[0035] Each damping subassembly comprises, for example, a single damping pad 18 or two or more damping pads 18 mounted one after the other or in the extension of one another along the first extension axis 15.

[0036] Each damping subassembly may be housed in a shoulder 22 provided at each end 23, 24 of the sleeve 14 along the first extension axis 15. Each shoulder 22 has, for example, a stop surface which is arranged substantially perpendicular to the first extension axis 15, which is oriented in a direction opposite to the other shoulder 22, and against which the or one of the damping pads 18 of one of the damping subassemblies is arranged. The stop surfaces of the shoulders 22 make it possible to keep the two damping subassemblies at a distance from each other and therefore to preserve the free space 21. The shoulders 22 may be replaced by circlips which are housed in grooves provided at each end 23, 24 of the sleeve 14 and which have the stop surfaces.

[0037] The or each damping pad 18 comprises, for example, a tubular inner metal cage extending around the second extension axis 17 and surrounding the shaft 16, a tubular outer metal cage which extends around the first extension axis 15, which surrounds the inner cage and which is surrounded by the sheath 14, as well as a tube made of elastomeric material interposed between the inner cage and the outer cage and mounted integrally between said inner and outer cages. The inner and outer cages are, for example, made from steel. The tube made of elastomeric material is, for example, made from vulcanized rubber.

[0038] Alternatively, the or each damping pad 18 may comprise only a tube made of elastomeric material, such as polyurethane, extending around the first and second extension axes 15, 17.

[0039] The or at least one of the damping pads 18 may also comprise grooves, notches, recesses or alveoli provided in the tube made of elastomer material, so as to promote the movement of the sheath 14 and the shaft 16 relative to each other in the direction or directions taken radially relative to the second extension axis 17 and having such grooves, notches, recesses or alveoli. This thus makes it possible to obtain differentiated damping depending on the direction in which said damping pad 18 is stressed by the sheath 14 and the shaft 16.

[0040] When each damping subassembly comprises several damping pads 18, the damping pads 18 within each damping subassembly may have different damping properties. For this purpose, the elastomer material tubes of said damping pads 18 may, for example, have a different hardness and / or be filled with fibers and / or have recesses or cells.

[0041] The ball joint 19 is mounted between the sleeve 14 and the shaft 16. The shaft 16 and the sleeve 14 are thus articulated relative to each other. The ball joint 19 not only allows the shaft 16 and the sleeve 14 to pivot relative to each other around the second extension axis 17, but also around axes which are perpendicular to the second extension axis 17. The ball joint 19 thus accompanies the oscillations of the shaft 16 and the sleeve 14 relative to each other, these oscillations being, where appropriate, damped by the damping stud(s) 18. The ball joint 19 also allows the forces between the main arm 12 and the central frame 11 to be taken up. It prevents the structural collapse of the spray bar 10, but also the continuous crushing of the damping stud(s) 18.

[0042] The ball joint 19 surrounds the shaft 16 and is itself surrounded by the sleeve 14. The ball joint 19 is interposed between the sleeve 14 and the shaft 16 in the first radial direction.

[0043] The ball joint 19 comprises, for example, a nut 25 through which the shaft 16 passes and housed in a cage 26 which is mounted in the sheath 14.

[0044] The shaft 16 is for example mounted freely pivoting in the nut 25 of the ball joint 19 around the second extension axis 17, in particular by means of a mounting with clearance. The cage 26 of the ball joint 19 can be mounted freely pivoting in the sleeve 14 around the first extension axis 15, in particular by means of a mounting with clearance.

[0045] The cage 26 of the ball joint 19 can still be locked in translation in the sheath 14 along the first extension axis 15 by means of first translation locking members, such as first circlips 27 housed in grooves provided in the sheath 14, on each side of the cage 26 along the first extension axis 15.

[0046] The ball joint 19 is for example arranged in the free space 21, between the two damping sub-assemblies.

[0047] The guide member 20 has a generally tubular shape extending around the second extension axis 17. The guide member 20 further surrounds the shaft 16, with which it is therefore coaxial, and is itself surrounded by the sleeve 14. The guide member 20 is thus interposed between the sleeve 14 and the shaft 16 in the first radial direction. The shaft 16 passes, for example, right through the guide member 20.

[0048] The shaft 16 is for example mounted freely pivoting in the guide member 20 around the second extension axis 17, in particular by means of a mounting with play.

[0049] The guide member 20 is for example arranged in the free space 21, between the two damping sub-assemblies. Damping pads 18 of the two damping sub-assemblies can grip the guide member 20 along the first extension axis 15. Each end 28, 29 of the guide member 20 along the first extension axis 15 is thus in contact with the or one of the damping pads 18 of the two damping sub-assemblies along the first extension axis 15.

[0050] Alternatively ( figures 5 And 6), the guide member 20 passes through at least one of the damping pads 18. The guide member 20 is thus surrounded by the damping pad(s) 18 which it passes through, interposing itself between said damping pad(s) 18 and the shaft 16.

[0051] The or each damping pad 18 that the guide member 20 passes through can be mounted to pivot freely relative to the guide member 20 around the second extension axis 17, in particular by means of a mounting with clearance.

[0052] Alternatively, the guide member 20 is mounted pivotably in the damping stud(s) 18 which it passes through around the second extension axis 17, in particular by means of a tight assembly.

[0053] The ball joint 19 is for example mounted between the sleeve 14 and the shaft 16 by means of the guide member 20, so as to articulate the shaft 16 and the sleeve 14 relative to each other, by means of the guide member 20. The ball joint 19 thus accompanies the oscillations of the shaft 16 and the sleeve 14 relative to each other, by means of the guide member 20. The ball joint 19 therefore surrounds the guide member 20, which itself surrounds the shaft 16. The ball joint 19 is thus interposed between the sleeve 14 and the guide member 20 in the first radial direction.

[0054] For this, the nut 25 of the ball joint 19 is for example crossed by the guide member 20. The guide member 20 protrudes in particular on each side of the nut 25 of the ball joint 19 along the second extension axis 17.

[0055] The guide member 20 can furthermore be mounted freely pivoting in the nut 25 of the ball joint 19 around the second extension axis 17, in particular by means of a mounting with play.

[0056] The guide member 20 is for example locked in translation relative to the ball joint 19 along the second extension axis 17 by means of second translation locking members, such as second circlips 30 housed in grooves formed in the guide member 20, opposite and on each side of the nut 25 of the ball joint 19 along the second extension axis 17. This translation locking of the guide member 20 makes it possible to take up axial forces, but also to avoid any deformation of the damping stud(s) 18 in the event of sliding of the shaft 16 along the second extension axis 17.

[0057] The guide member 20 makes it possible in particular to facilitate the mounting of the shaft 16 through the ball joint 19, in particular by imposing an angular movement on the pivoting of the nut 25 of the ball joint 19 around the axes perpendicular to the second extension axis 17, this angular movement preventing the nut 25 from pivoting in such a way that it can no longer be crossed by the shaft 16.

[0058] As a replacement for the ball joint 19, the guide member 20 is for example mounted to pivot freely relative to the sheath 14 around a pivot axis 50, arranged perpendicular to the first extension axis 15, and pivotally secured relative to the sheath 14 around axes perpendicular to the pivot axis 50. The guide member 20 then forms a universal joint 51 ( figures 4 And 6). The guide member 20 not only allows the shaft 16 and the sheath 14 to pivot relative to each other around the second extension axis 17, but also around the pivot axis 50. The guide member 20 thus accompanies the oscillations of the shaft 16 and the sheath 14 relative to each other, these oscillations being, where appropriate, damped by the damping stud(s) 18. The guide member 20 also allows the forces between the main arm 12 and the central frame 11 to be taken up. It prevents the structural collapse of the spray bar 10, but also the continuous crushing of the damping stud(s) 18.

[0059] For this, a rod 52 passes for example through the sheath 14 and the guide member 20 along the pivot axis 50, on each side of the shaft 16.

[0060] A lubrication circuit 53 is for example also provided, so as to ensure the pivoting of the sleeve 14 and the shaft 16 relative to each other, and where appropriate, of the damping stud(s) 18 and / or the ball joint 19 and / or the guide member 20. The lubrication circuit 53 makes it possible to avoid problems of seizure.

[0061] The lubrication circuit 53 comprises, for example, a first channel 54 passing right through the sleeve 14 generally in the first radial direction as far as the ball joint 19, in particular the cage 26 of the ball joint 19, one or more second channels 55 passing right through the ball joint 19, in particular the nut 25 of the ball joint 19, generally in the first radial direction, as well as, where appropriate, one or more third channels 56 passing right through the guide member 20 generally in the first radial direction. The cage 26 of the ball joint 19 may also be provided with a groove 57 arranged around the first extension axis 15 and arranged opposite the first channel 54. A hydraulic lubricator 58, in particular surmounted by a cap, may also be mounted in the first channel 54.

[0062] Alternatively, the lubrication circuit comprises a channel passing right through the shaft 16 from a first section extending along the second extension axis 17 to one or more second sections extending from the first section generally along a second radial direction, taken relative to the second extension axis 17. A hydraulic lubricator can also be mounted in the first section of the channel.

[0063] The main arm 12 may comprise an elongated body 31 extending along a main extension axis 32.

[0064] The spray boom 10 is for example designed to occupy a spray configuration in which the main extension axis 32 of the body 31 of the main arm 12 is oriented generally transversely ( figure 1) and a rest configuration in which the main extension axis 32 of the body 31 of the main arm 12 is included in a generally longitudinal and vertical plane. Alternatively, in the rest configuration, the main extension axis 32 of the body 31 of the main arm 12 is included in a generally transverse and vertical plane.

[0065] The spray boom 10 occupies, for example, the spraying configuration when the agricultural spraying system 100 travels through the field of plants to be treated to spray them with treatment liquid. The spray boom 10 occupies, for example, the rest configuration while the agricultural spraying system 100 is traveling on the road, the transverse size of the agricultural spraying system 100 then being reduced.

[0066] The first extension axis 15 is for example oriented generally longitudinally, when the spray bar 10 occupies the spray configuration. Alternatively (not shown), the first extension axis 15 is oriented generally vertically, when the spray bar 10 occupies the spray configuration. In the rest configuration, the first extension axis 15 may or may not have the same orientation as in the spray configuration. By "generally longitudinally" or "generally vertically" is meant that the first extension axis 15 is oriented longitudinally or vertically to within 10°.

[0067] The pivot axis 50 is for example oriented generally vertically, when the spray bar 10 occupies the spray configuration. Alternatively (not shown), the pivot axis 50 is oriented generally horizontally, when the spray bar 10 occupies the spray configuration. In the rest configuration, the pivot axis 50 may or may not have the same orientation as in the spray configuration. By "generally vertically" or "generally longitudinally" is meant the pivot axis 50 is oriented longitudinally or vertically to within 10°.

[0068] The change of configuration of the spraying boom 10 between its spraying and rest configurations is for example achieved by pivoting the main arm 12 relative to the central frame 11 around the first extension axis 15. As a variant (not shown), this change of configuration is achieved on the one hand by pivoting the main arm 12 relative to the central frame 11 around the first extension axis 15, and on the other hand, by pivoting a movable part of the central frame 11 carrying the sheath 14, relative to a fixed part of the central frame 11, around a pivot axis, which is neither parallel nor coincident with the first extension axis 15.

[0069] One or more jacks 33 may also be designed to drive the main arm 12 to pivot relative to the central frame 11 around the first extension axis 15 and / or the movable part to pivot relative to the fixed part of the central frame 11 around the pivot axis.

[0070] The or each secondary arm 13 may comprise an elongated body 35 extending along a main extension axis 36.

[0071] The or each secondary arm 13 is for example pivotally mounted on the main arm 12 or secondary arm 13 which precedes it relative to the central frame 11 around a pivot axis 37, generally perpendicular to the first extension axis 15. When the first structural element 10.1 of an assembly is formed by the main arm 12 or one of the secondary arms 13 and the second structural element 10.2 of this assembly is formed by the secondary arm 13 mounted on the main arm 12 or another of the secondary arms 13 mounted on one of the secondary arms 13, the pivot axis 37 coincides with the second extension axis 17.

[0072] Each secondary arm 13 may further be designed to pivot relative to the main arm 12 or secondary arm 13 preceding it, around the pivot axis 37, between an unfolded position in which the body 35 of said secondary arm 13 and the body 31, 35 of the main arm 12 or secondary arm 13 preceding it are generally aligned ( figure 1 ) with each other, in particular along the transverse direction Y in the spraying configuration of the spray bar 10, and a folded position in which the body 35 of said secondary arm 13 is superimposed on the body 31, 35 of the main arm 12 or secondary arm 13 which precedes it.

[0073] The unfolded and folded positions make it possible to vary a transverse dimension or span of the spray boom 10, when the main arm 12 occupies its spraying position, in particular depending on the dimensions of the field of plants to be treated. The folded position also makes it possible to reduce the size of the spray boom 10, when the main arm 12 occupies its rest position.

[0074] One or more jacks (not shown) may also be designed to pivot the or each secondary arm 13 around their pivot axis 37 between the unfolded and folded positions.

[0075] The main arm 12 and, where appropriate, the secondary arm(s) 13 support, for example, a plurality of nozzles 38 designed to spray treatment liquid onto the plants to be treated in the field. The nozzles 38 are oriented generally vertically downwards.

[0076] The nozzles 38 are further supplied with spraying liquid by one or more supply lines (not shown) which may themselves be supported by the main arm 12 and, where appropriate, the secondary arm(s) 13. The supply line(s) are further connected to a supply circuit (not shown) taking treatment liquid from a tank 102 supported by the agricultural spraying system 100.

[0077] The spray bar 10 described above is particularly advantageous because it uses a space-saving and simple-design anti-whipping device 10.3.

Claims

1. Assembly for spray boom (10) of an agricultural spraying system (100) comprising: - a first structural element (10.1), - a second structural element (10.2), one among the first structural element (10.1) and the second structural element (10.2) comprising a sheath (14) extending about a first extension axis (15), the other among the first structural element (10.1) and the second structural element (10.2) comprising a shaft (16) extending along a second extension axis (17), the shaft (16) being surrounded by the sheath (14) and pivotably mounted in the sheath (14) about the second extension axis (17), - an anti-whipping device (10.3) designed to cushion a whipping of the first structural element (10.1) and of the second structural element (10.2) with respect to one another, the assembly being characterized in that the anti-whipping device (10.3) is mounted inside the sheath (14), between the shaft (16) and the sheath (14).

2. Assembly according to claim 1, wherein the anti-whipping device (10.3) is designed to passively cushion the whipping of the first structural element (10.1) and of the second structural element (10.2) with respect to one another.

3. Assembly according to claim 1 or claim 2, wherein the anti-whipping device (10.3) comprises at least one cushioning stud (18), the or each cushioning stud (18) having a globally tubular shape extending about the first and second extension axes (15, 17), the or each cushioning stud (18) surrounding the shaft (16) and being itself surrounded by the sheath (14).

4. Assembly according to one of claims 1 to 3, wherein the anti-whipping device (10.3) comprises a ball-joint (19) mounted between the sheath (14) and the shaft (16), the shaft (16) thus being articulated inside the sheath (14).

5. Assembly according to one of claims 1 to 3, wherein the anti-whipping device (10.3) comprises a guide member (20) having a globally tubular shape extending about the second extension axis (17), the guide member (20) surrounding the shaft (16) and being itself surrounded by the sheath (14).

6. Assembly according to claim 5, wherein the anti-whipping device (10.3) comprises a ball-joint (19) mounted between the guide member (20) and the sheath (14), in such a way as to articulate the shaft (16) inside the sheath (14) via the guide member (20).

7. Assembly according to claim 5, wherein the shaft (16) is mounted free to pivot in the guide member (20) about the second extension axis (17) and wherein the guide member (20) is mounted free to pivot with respect to the sheath (14) about a pivot axis (50), arranged perpendicularly to the first extension axis (15), and integral in pivoting with respect to the sheath (14) about axes perpendicular to the pivot axis (50), the guide member (20) thus forming a yoke (51).

8. Assembly according to one of claims 1 to 7, wherein the anti-whipping device (10.3) comprises two cushioning sub-assemblies arranged at a distance from one another along the first extension axis (15), each cushioning sub-assembly comprising at least one cushioning stud (18), each cushioning stud (18) having a globally tubular shape extending about the first and second extension axes (15, 17), each cushioning stud (18) further surrounding the shaft (16) and being itself surrounded by the sheath (14).

9. Spray boom (10) for an agricultural spraying system (100) comprising a central frame (11), at least one main arm (12) mounted on the central frame (11) and at least one assembly according to one of claims 1 to 8.

10. Spray boom (10) according to claim 9, further comprising at least one secondary arm (13) mounted in the extension of the or of one of the main arms (12), said main arm (12) and one or more secondary arms (13) succeeding from the central frame (11) to a free end of the spray boom (10).

11. Spray boom (10) according to claim 9 or claim 10, wherein: - the first structural element (10.1) of at least one assembly is formed by the central frame (11) and the second structural element (10.2) of the at least one assembly is formed by the or one of the main arms (12); and / or - the first structural element (10.1) of at least one assembly is formed by the or one of the main arms (12) and the second structural element (10.2) of the at least one assembly is formed by the secondary arm (13) mounted on said main arm (12); and / or the first structural element (10.1) of at least one assembly is formed by one of the secondary arms (13), while the second structural element (10.2) of the at least one assembly is formed by another of the secondary arms (13) that is mounted on one of the secondary arms (13).

12. Agricultural spraying system (100) for an agricultural machine comprising a spray boom (10) according to one of claims 9 to 11.