Two-shaft coupling device and single-tool engagement device

Abstract

A coupling device for two shafts and a coupling device fitted with such a coupling device. A coupling device for two shafts end-to-end, comprising a pair of thrust clutches (16, 28). Each thrust clutch is shaped so as to be able to become integral with one end of the shaft to be coupled, and the two thrust clutches (16, 28) are of complementary shapes. A first thrust clutch (16) is pivoting in a first housing (6). A second thrust clutch (28) is pivoting in an intermediate bearing (8). The intermediate bearing (8) is sliding in a second housing (10) assumed to be fixed, the intermediate bearing (8) being able to slide relative to the second housing (10) in a direction parallel to the two shafts to be coupled, said longitudinal direction. The intermediate bearing (8) is elastically pre-tensioned towards the first housing (6).

Description

1 / 40 “TWO-SHAFT COUPLING DEVICE AND SINGLE-TOOL ENGAGEMENT DEVICE

[001] The present invention relates to a coupling device for two shafts. More particularly, it relates to a coupling between a driving shaft and a driven shaft. The invention also relates to a coupling device comprising a coupling device for two shafts. Technical expertise

[002] The technical problem at the origin of the device that will be described later is to semi-automatically couple a driven shaft to a drive shaft when a tool equipped with a receiving shaft, such as an agricultural tool, is coupled to a machine, such as an agricultural tractor, equipped with a drive shaft, commonly called a power take-off in the agricultural field. The semi-automatic coupling allows the machine operator to perform the coupling from a machine operating station, which remains at a distance from the coupling means. Previous technique

[003] Each of documents FR2995756 and FR3018029 refers to a hitch device specifically intended for attaching an agricultural tool to a machine such as an agricultural tractor. The tool is then fitted with a hitch frame, while the machine is fitted with a hitch frame.

[004] These documents show means of performing a semi-automatic coupling of a tool to a machine, the said coupling being performed by a machine operator without Petition 870230040777, dated 05 / 16 / 2023, page 8 / 53 2 / 40 that he has to leave his driving position.

[005] Document EP2098741 refers to a disengagement / disconnection assembly for disengaging a generator from a gearbox, comprising a first ball screw having an inclined thread on its outer surface and encircling and engaging with a rotating shaft of the generator motor to drive the rotation of the ball screw. The ball screw may be fixed to an engagement element having interlocking notched teeth engaged with corresponding teeth of a gearbox engagement element. An outer ball screw may encircle and pivot normally with the inner ball screw. A helical ball track may be formed between the inner and outer ball screws.A brake may be provided to slow down or stop the rotation of the outer ball screw so that the inner ball screw pivots relative to the outer ball screw along the ball race and slides axially from the gearbox, thereby disengaging the generator from the drive shaft of the gearbox.

[006] The technical problem is to improve existing systems, notably by simplifying them, while ensuring, on the one hand, a semi-automatic engagement and, on the other hand, perfect power transmission from the machine to the tool in all circumstances. Summary

[007] This disclosure will improve the situation.

[008] A device for coupling two shafts end-to-end is proposed, comprising a pair of clutches. Petition 870230040777, dated 05 / 16 / 2023, page 9 / 53 3 / 40 thrust, each thrust clutch being shaped in such a way as to be able to become integral with one end of the shaft to be coupled and the two thrust clutches being of complementary shapes.

[009] According to the present invention, a first thrust clutch is pivoting in a first crankcase; a second thrust clutch is pivoting in an intermediate bearing; the intermediate bearing is sliding in a second crankcase assumed to be fixed, the intermediate bearing being able to slide relative to the second crankcase in a direction parallel to the two shafts to be coupled, said longitudinal direction, and the intermediate bearing is elastically pretensioned towards the first crankcase.

[0010] Such a structure allows two shafts to be coupled, each shaft being mounted in rotation in its own housing. A thrust clutch is associated with each shaft. For coupling, the shafts are then aligned and driven towards each other. There is then little chance that the thrust clutches will be oriented relative to each other in such a way that the teeth of the thrust clutches engage directly. One shaft can be rotated relative to the other to obtain a relative orientation of the thrust clutches allowing their translational engagement. The proposed structure then allows one thrust clutch to move axially relative to the other and then ensure good engagement of the teeth of the thrust clutches thanks to elastic pre-tension.

[0011] Here, a thrust clutch pair is understood to be a mechanical coupling means comprising teeth and grooves enabling direct coupling with a means of Petition 870230040777, dated 05 / 16 / 2023, page 10 / 53 4 / 40 coupling of the same type, in a complementary way.

[0012] To facilitate the alignment of the shafts, it can be foreseen, for example, that the first crankcase has a first conical surface facing the second crankcase, that the second crankcase has a second conical surface facing the first crankcase, the two conical surfaces being of complementary shapes in order to achieve an alignment of the two shafts, that the first conical surface or the second conical surface is mounted sliding longitudinally in relation to the crankcase that holds it, and that the sliding conical surface is elastically pre-tensioned towards the other conical surface.

[0013] In this last embodiment, to ensure that good alignment is achieved before the thrust clutches engage, it can advantageously be provided that the sliding conical surface and the corresponding housing are equipped with retarding devices such that the displacement of said conical surface cannot be initiated except when a predefined minimum longitudinal tension is exerted on said conical surface for the housing that holds it. Here the centering devices corresponding to the conical surfaces (male and female), which are of complementary shapes, fit together and allow perfect pre-positioning of the coupling devices formed by the thrust clutches. It is thus ensured that the coupling devices are well positioned relative to each other so as to avoid any mechanical breakage. Preferably, a phase is provided in which the thrust clutches are perfectly aligned, but not yet in contact with each other. Petition 870230040777, dated 05 / 16 / 2023, page 11 / 53 5 / 40

[0014] According to an advantageous embodiment, the retarding means may comprise at least one guide rod integral with the sliding conical surface; said guide rod may comprise a contracted section zone capable of sliding in a perforation within the corresponding crankcase; the corresponding crankcase may comprise a slot extending transversely with respect to the perforation receiving at least partially the guide rod and intercepting said perforation, and an elastic element (by way of non-limiting example; a beta pin) having two branches may be housed in said slot, the contracted section being disposed between the two branches of the elastic element (for example, the beta pin).

[0015] The expert in the technique will immediately know how to find other means to perform the aforementioned retarding function. This function can, for example, also be performed by one or more elastically pre-tensioned tabs. Although in these examples this function is performed mechanically in an automatic way, it can also be controlled and performed by an actuator, for example hydraulic. This retarding function is advantageous to ensure a pre-positioning of the coupling elements (thrust clutches) and a thrust clutch without risk of breakage.

[0016] An advantageous embodiment of such a coupling device may further provide that said device comprises connecting and locking means, said means comprising on either side of a thrust clutch, a corresponding crankcase projection, the other crankcase bearing, on one side, of Petition 870230040777, dated 05 / 16 / 2023, page 12 / 53 6 / 40 each time, guide means for bringing a protrusion into a housing and, on the other hand, a pivoting hook mounted around a transverse axis between a position said to be open allowing the protrusion to enter and exit its housing and a position said to be closed in which the hook can hold the protrusion in its housing preventing it from exiting.

[0017] In this modality, it can also be predicted that: - the two hooks are mounted pivotally on a common transverse axis and the movement of the hooks is controlled by a double-acting hydraulic actuator; and / or - at least one hook bearing a locking pin intended to cooperate with a pair of claws, said claws being carried by the same housing (10) as that which bears the hooks and being arranged in such a way that the locking pin is between the claws when the corresponding hook is in the closed position.

[0018] In the case where claws are provided, it can then be foreseen, for example, that for each pair of claws, one claw is fixed and the other is movable, that a spring pretensions the movable claw towards the fixed claw, and that an actuator allows action against the spring to move the movable claw away from the fixed claw.

[0019] According to another aspect, a device is proposed for attaching a tool, such as an agricultural tool, to a lifting system of a machine, such as an agricultural tractor, equipped with an output drive shaft, comprising: - a first frame, called the hitch frame, equipped with fastening devices allowing attachment to the machine's lifting system, Petition 870230040777, dated 05 / 16 / 2023, p. 13 / 53 7 / 40 - a second frame called the engaged frame and equipped with fastening devices allowing attachment to the tool, each of the engagement frame and the engaged frame having a joining face, said joining faces being adapted to allow the engagement frame to be paired with the engagement frame, - means of relatively locking the engaged frame onto the engagement frame in the paired position, characterized in that said engagement device also includes a coupling device for two shafts end-to-end as described above, said coupling device being intended to be mounted between the output drive shaft of the machine and a driven shaft of the tool.

[0020] In such a coupling device, the engaged frame may for example comprise two pivoting mounted arms between an approximate position in which the free ends of the arms bear the first crankcase of the coupling device and an open position in which the arms are spread apart and their free ends are away from the first crankcase.

[0021] In a preferred embodiment of this coupling device, the coupling frame has a welded structure comprising a crossbar from which two legs extend on the same side of said crossbar; the coupled frame may in turn have a welded structure comprising an upper crossbar, a lower crossbar and two uprights connecting the ends of the lower crossbar to the ends of the upper crossbar; the crossbar of the coupling frame advantageously has at least two centering pins. Petition 870230040777, dated 05 / 16 / 2023, page 14 / 53 8 / 40 and the upper crossbar of the engaged frame has a cover that extends to the engagement frame and has at least two housings, each intended to receive a centering pin.

[0022] In this embodiment, it can also be foreseen that each leg of the hitch frame has at its free end a plate on which at least one locking finger is placed and that the lower crossbar of the hitched frame has locking holes arranged in such a way as to accommodate the locking fingers.

[0023] According to a preferred embodiment, the engagement device comprises, for example, means of actuating the mounted pivoting arms, said means of actuating cooperating with the plate on which at least one locking finger is disposed, such that in the locking position of the frame engaged on the engagement frame, the arms are in their open position.

[0024] For a coupling device as described herein, it is provided for example that the first housing of the coupling device is mounted on the side of the engaged frame, while the second housing is mounted on the side of the coupling frame. Brief description of the drawings

[0025] Other features, details and advantages will become apparent from reading the detailed description below and analyzing the attached drawings, in which: Fig. 1

[0026] Fig. 1] shows a perspective view of a two-shaft coupling device. Fig. 2 Petition 870230040777, dated 05 / 16 / 2023, page 15 / 53 9 / 40

[0027] [Fig. 2] is a longitudinal cross-sectional view along the section line II-II of the coupling device in a first position. Fig. 3

[0028] Fig. 3] is a longitudinal cross-sectional view along the section line II-II of the coupling device in a second position. Fig. 4

[0029] [Fig. 4] is a longitudinal cross-sectional view along the section line II-II of the coupling device in a third position. Fig. 5

[0030] [Fig. 5] is a detailed cutaway view in the first position of figure 2. Fig. 6

[0031] [Fig. 6] is another detailed cutaway view in the first position of figure 2. Fig. 7

[0032] [Fig. 7] schematically shows an agricultural tool fitted with an attached frame and part of a coupling device as shown in Figure 1. Fig. 8

[0033] [Fig. 8] schematically shows a rear section of an agricultural tractor fitted with a hitch frame and part of a coupling device as shown in the figure. 1. Fig. 9

[0034] [Fig. 9] shows a side view of the rear of the agricultural tractor in figure 8 facing the agricultural implement in figure 7 before hitching. Petition 870230040777, dated 05 / 16 / 2023, page 16 / 53 10 / 40 Fig. 10

[0035] [Fig. 10] shows a first stage of attaching the tool from figure 7 to the rear of the tractor in figure 8. Fig. 11

[0036] [Fig. 11] shows a second stage of attaching the tool from figure 7 to the rear of the tractor in figure 8 with a detailed view of part of the coupling device. Fig. 12

[0037] [Fig. 12] shows a third stage of attaching the tool from figure 7 to the rear of the tractor in figure 8 with a detailed view of part of the coupling device. Fig. 13

[0038] [Fig. 13] shows a fourth stage of the tool engagement of figure 7 attached to the rear of the tractor of figure 8 with a detailed view of a part of the coupling device. Fig. 14

[0039] [Fig. 14] shows a fifth stage of the tool engagement of figure 7 on the rear of the tractor of figure 8 with a detailed view of a part of the coupling device. Fig. 15

[0040] [Fig. 15] shows the tool of figure 7 in the engaged position on the rear of the tractor of figure 8 with a detailed view of a part of the coupling device. Fig. 16 Petition 870230040777, dated 05 / 16 / 2023, page 17 / 53 11 / 40

[0041] [Fig. 16] is a top view corresponding to figure 14. Fig. 17

[0042] [Fig. 17] is a top view corresponding to figure 15. Fig. 18

[0043] [Fig. 18] is an elevation view of a frame from the tool side corresponding to figure 14. Fig. 19

[0044] [Fig. 19] is an elevation view of the engaged frame of figure 18 in its corresponding position to figure 15. Fig. 20

[0045] [Fig. 20] is a perspective view of a detail of the engaged frame. Fig. 21

[0046] [Fig. 21] is a detailed, enlarged-scale bottom view of the two assembled frames. Fig. 22

[0047] [Fig. 22] is a side view of the coupling device of figure 1 mounted on a support and fitted with a locking device in the open position. Fig. 23

[0048] [Fig. 23] is a view similar to figure 22 with the locking device in the closed position without the support. Fig. 24

[0049] [Fig. 24] is a view similar to figure 23 with the support, but with spring retraction. Fig. 25

[0050] [Fig. 25] is a rear view of part of Petition 870230040777, dated 05 / 16 / 2023, page 18 / 53 12 / 40 coupling device illustrated in figures 22 to 24. Description of the modalities

[0051] The attached drawings and the description below contain, in essence, elements of a certain character. Thus, they may not only serve to make the present disclosure better understood, but also contribute to its definition, if necessary.

[0052] Reference is now made to Figure 1. It represents a device allowing the coupling of two shafts. It is assumed here that the two shafts to be coupled are splined shafts, one shaft having a male end, while the other has a female end. The device illustrated in Figure 1 then comprises a male coupling piece 2 (to receive the female end of the shaft) as well as a female coupling piece 4 (to cooperate with the male end of the shaft). A person skilled in the art will understand from reading the following description that the coupling device described can also couple two shafts each having a male end or two shafts with female ends.

[0053] The male coupling piece 2 is mounted by means of bearings in a first crankcase 6, while the female coupling piece 4 is mounted by means of bearings in an intermediate bearing 8, which in turn is mounted slidingly in a second crankcase 10 distinct from the first crankcase 6. This structure will be better understood in connection with figures 2, 3 and 4 which show the device of figure 1 in longitudinal section.

[0054] It is considered in the following description that the Petition 870230040777, dated 05 / 16 / 2023, page 19 / 53 13 / 40 longitudinal direction is the direction given by the coupled shafts and thus also here by the female coupling piece 2 and the male coupling piece 4.

[0055] The male coupling piece 2 has a connecting end 12, a solid cylindrical body 14 and a first head with thrust clutch 16.

[0056] The connecting end 12 is shaped to fit a shaft end. It is intended here to cooperate with a female housing (not shown). In the embodiment illustrated by way of non-limiting example, the connecting end 12 is in the form of a grooved shaft. This end extends into the solid cylindrical body 14. The latter is intended to carry a pair of bearings 18 and its outer peripheral surface is machined to receive these bearings 18. This surface is not described in detail. It does, however, include, for example, a bearing stop, a machined surface serving as a seat for the bearings 18, a threaded part to receive a nut 20 as well as an area intended to cooperate with a sealing gasket 22 to protect the bearings 18.

[0057] The first head with thrust clutch 16 can only form a single piece with the solid cylindrical body 14 and the connecting end 12. This piece is obtained in the example illustrated by machining. The first head with thrust clutch 16 forms the end of this piece opposite the connecting end 12. It has a larger diameter than the solid cylindrical body 14. It has a transverse face from which teeth 24 project regularly arranged on the periphery of this transverse face. Petition 870230040777, dated 05 / 16 / 2023, page 20 / 53 14 / 40

[0058] The female coupling piece 4 in turn has a tubular cylindrical body 26 and a second head with a thrust clutch 28. The first head with a thrust clutch 16 and the second head with a thrust clutch 28 together form a thrust clutch device, that is, a direct coupling device of two pieces, or thrust clutches, by teeth and grooves.

[0059] The tubular cylindrical body 26 has a housing 30 adapted to receive a shaft end to be coupled. Naturally, it is then necessary to adapt the shape of the housing 30 to the shape of the shaft. In the illustrated embodiment, the housing 30 is a housing to receive a splined shaft (not shown). The outer surface of this tubular cylindrical body is machined to receive a pair of bearings 18'. This surface is not described in detail. However, it includes, for example, a bearing stop, a machined surface serving as a seat for the bearings 18', a threaded part to receive a nut 20' and an area to receive a sealing gasket 22' in order to protect the bearings 18'.

[0060] The second head with thrust clutch 28 is adapted to cooperate with the first head with thrust clutch 16. The diameter of this second head with thrust clutch 28 corresponds to the diameter of the first head with thrust clutch 16. This second head with thrust clutch 28 in turn has a transverse face from which project teeth 24'. These latter are intended to mesh with the teeth 24 of the first head with thrust clutch 28.

[0061] The first crankcase 6 is a tubular piece whose Petition 870230040777, dated 05 / 16 / 2023, page 21 / 53 The 15 / 40 inner surface is machined to receive the outer rings of the bearings 18. The housing formed inside this first crankcase 6 to receive the bearings 18 is closed at one end by the sealing gasket 22. On the opposite side to this gasket, i.e., on the side of the first head with thrust clutch, a sealing gasket 22 is similarly provided between the first head with thrust clutch 16 and the first crankcase 6.

[0062] On the side of the first head with thrust clutch 16, the first crankcase 6 has a first centering ring 32 which, in the embodiment proposed in the drawing, is a piece distinct from the first crankcase 6 and is screwed onto a side face provided for this purpose on the first crankcase 6 on the side of the first head with thrust clutch 16. This first centering ring 32 has a truncated conical outer surface which is coaxial with the first crankcase 6 and the male coupling piece 2.

[0063] On the opposite side of the first head with thrust clutch 16, the first crankcase 6 is fitted with means of attachment to a support 34. The latter is made of several parts. In the illustrated embodiment, the support 34 comprises a square-shaped piece with a base 36 and two branches 38. The base 36 extends transversely in relation to the male coupling piece 2 and serves to fix the support 34 onto the first crankcase 6. A flange 40 mounted on the first crankcase 6 is used to secure the support 34, more precisely the base 36, onto the first crankcase 6. The branches 38 of the square-shaped piece extend perpendicularly to the base towards the first head with Petition 870230040777, dated 05 / 16 / 2023, page 22 / 53 16 / 40 thrust clutch 16. Each branch 38 bears a finger 42 that extends from the branch 38 outward from the square, i.e. away from the first crankcase 6. The two fingers 42 are arranged on the branches 38 in such a way as to be coaxial (and they then extend transversely in relation to the male coupling piece 2). Each branch 38 also bears a side fastening piece 44 that extends longitudinally outward, away from the first crankcase 6. These side fastening pieces 44 are adapted to the tool on which the support 34 and the corresponding male coupling piece 2 are to be mounted. In the embodiment illustrated as a non-limiting illustrative example, each of the side fastening pieces 44 has a fastening plate on the outer face of which a U-shaped profiled piece 46 is fixed, the free edges of the branches of the U being widened and the profiled piece 46 being oriented longitudinally.

[0064] As mentioned above, the female coupling piece 4 is disposed in the intermediate bearing 8, which in turn is mounted movably in longitudinal translation in the second crankcase 10 assumed to be fixed.

[0065] The intermediate bearing 8 is a tubular piece whose inner surface is machined to receive the outer rings of the bearings 18' in which the female coupling piece 4 is mounted. The housing formed inside this intermediate bearing 8 to receive the bearings 18' is closed at one end by the sealing gasket 22'. On the opposite side to this gasket, i.e., on the side of the second head with thrust clutch 28, another sealing gasket 22' is also provided between the second head with thrust clutch 28 and the intermediate bearing 8. Petition 870230040777, dated 05 / 16 / 2023, page 23 / 53 17 / 40

[0066] The intermediate bearing 8 also has a side face 48, on the side of the second head with thrust clutch 28. This side face 48 carries the sealing gasket 22'. It may also be fitted with longitudinal holes provided to allow its guidance in relation to the second crankcase 10 as well as longitudinal holes for the passage of guide rods as explained later with particular reference to figures 5 and 6.

[0067] The second crankcase 10 is assumed to be fixed in the present description. It thus serves as a reference for the relative movements of the different parts that will be explained subsequently. The second crankcase 10 has a generally parallelepiped shape with a central longitudinal through hole in which the movable assembly formed by the female coupling piece 4 and the intermediate bearing 8 slides. On the periphery of this central hole, there are, on one side, longitudinal blind holes and, on the other side, longitudinal through holes. In the illustrated embodiment, four blind holes and four through holes are provided. The four blind holes are similar, with a thread at the bottom of the hole, arranged longitudinally and opening onto the same face, called the rear face, of the second crankcase 10.

[0068] As already mentioned, the female coupling piece 4 and the intermediate bearing 8 form a movable assembly in relation to the second crankcase 10. This guidance is achieved by the central perforation of the second crankcase 10. In the embodiment illustrated by way of non-limiting example, a die 50 disposed between two scraper joints 52 is provided between the outer face of the intermediate bearing and the surface Petition 870230040777, dated 05 / 16 / 2023, p. 24 / 53 18 / 40 interior of the central drilling of the second crankcase 10.

[0069] For guiding the moving assembly, notably to prevent rotation of this moving assembly relative to the second crankcase 10, four first guide rods 54 are provided. With reference to Figure 5, which is an enlarged scale cutaway view of the coupling device in the first position of Figure 2, but in a longitudinal cutting plane passing through a first guide rod 54. The latter is in the form of a screw with a head, a body, and a threaded end opposite the screw head. The threaded end of each first guide rod 54 is screwed into a blind hole in the second crankcase 10. The body of each first guide rod 54 forms a guide column for the side face 48 of the intermediate bearing 8. The screw head of each first guide rod 54 forms a projection that serves as a stop for the side face 48 as illustrated in Figure 5.The side face 48 being located between the screw heads and the rear face of the second crankcase 10, that is, the face where the blind holes open, the maximum stroke of the moving assembly is defined by the distance that separates the screw head of each first guide rod 54 from the rear face of the second crankcase 10, minus the thickness of the side face 48.

[0070] The second crankcase 10 also has a second centering ring 56 designed to cooperate with the first centering ring 32. While the first centering ring 32 has an outer conical surface, the second centering ring 56 has an inner conical surface. These two conical surfaces, more precisely truncated cones, have the same angle at the vertex. Petition 870230040777, dated 05 / 16 / 2023, page 25 / 53 19 / 40 could come into contact with each other, adopting each other's form.

[0071] The second centering ring 56 is equipped with second guide rods 58 illustrated notably in figure 6. In the illustrated embodiment, four similar second guide rods 58 are provided.

[0072] Each second guide rod 58 has a threaded end that cooperates with a threaded hole made in the second centering ring 56 to join the second guide rod 58 with the second centering ring 56. For the correct relative positioning of the second guide rod 58 with the second centering ring 56, a projection of the second guide rod 58 cooperates with a projection made in the corresponding threaded hole.

[0073] Each second guide rod 58 then has a circular cylindrical body that passes through the side face 48 of the intermediate bearing 8 at the level of a hole provided for this purpose and that penetrates a through hole in the second crankcase 10. A narrowing extends the cylindrical body to a zone of narrowed diameter. This latter is followed by a projection and then the end of the second guide rod 58 meets a diameter corresponding to that of its cylindrical body. The end of the second guide rod 58 is provided with a central threaded hole that receives a screw that comes to hold a support washer 60.

[0074] In figure 2 (and in figure 6), it can be seen that the second crankcase 10 may have a slot 62 at the level of the narrowed diameter zone of the second guide rod 58. This slot 62 is then used to allow, for example, a pin to be inserted onto the second guide rod 58. Petition 870230040777, dated 05 / 16 / 2023, p. 26 / 53 20 / 40 beta 64. A beta pin is a pin that has two elastic branches pre-tensioned against each other. One branch is generally roughly straight, while the other branch presents, in relation to the first branch, a concave space between two convex spaces. Such a beta pin is then provided so that the first branch is housed in a transverse hole of a shaft, while the concave space then rests on an outer part of the shaft. In the coupling device described here, it is provided that one branch of the beta pin passes on one side of the second guide rod 58 and that the other branch passes on the other side of this rod, the latter being at the level of the concave space situated between two convex spaces of the pin.

[0075] It is also noted in figure 6 the presence of springs. One of the first springs 66 may be helical springs arranged around the cylindrical body of the second guide rods 58. These first springs 66 are thus held and guided by these rods and they are arranged between the lateral face 48 of the intermediate bearing 8 (movable) and the second crankcase 10 (fixed). These first springs 66 tend to move the side face 48 of the intermediate bearing 8 away from the rear face of the second crankcase 10, that is, to make the intermediate bearing 8 - and the female coupling piece 4 - come out of the central hole of the second crankcase 10. A second set of springs 68 can be housed in the holes of the second crankcase 10. Each of these second springs 68 is mounted between a stop plug 70 and a support washer 60 mounted at the end of a second guide rod 58.These second springs 68 tend to cause the second guide rods 58 to come out of their bore and thus move the second centering ring 56 away from the second crankcase 10. Petition 870230040777, dated 05 / 16 / 2023, page 27 / 53 21 / 40

[0076] With respect to the second crankcase 10, it may also have, as illustrated in the drawing, two transverse grooves made on two opposite faces in such a way that each receives a semi-flange 72 for fixing on a support 74 (visible in figures 5, 6 and 16, 17).

[0077] The operation of this two-shaft coupling device is explained with reference to figures 2 to 4.

[0078] Starting from a position such as illustrated in figure 9, where the male coupling piece 2 is away from the female coupling piece 4, these two coupling pieces are brought closer to each other; it is assumed here that the second crankcase 10 is fixed and thus that at first (between the position in figure 9 and that in figure 2), the moving assembly comprising the female coupling piece 4 and the intermediate bearing 8 as well as the second centering ring 56 is stationary.

[0079] When the first centering ring 32 comes into contact with the second centering ring 56, an alignment of the two rings is achieved in a known manner. This also aligns the male coupling piece 2 with the female coupling piece 4. When the alignment is achieved (first step illustrated in figure 2), the first head with thrust clutch 16 is still at a distance from the second head with thrust clutch 28. To achieve the coupling of the two shafts, it is necessary to engage the two heads with thrust clutches.

[0080] A second step (figure 3) is the contacting of the first head with thrust clutch 16 with the second head with thrust clutch 28. So that the first head with thrust clutch 16 can approach Petition 870230040777, dated 05 / 16 / 2023, page 28 / 53 22 / 40 of the second head with thrust clutch 28, it is necessary that the second centering ring 56 approaches the second crankcase 10. This displacement is prevented in the illustrated embodiment by the beta pins 64 arranged on the second guide rods 58. However, the beta pins 64 are elastic and when tension is exerted on the second guide rods 58, the branches of the beta pins 64 move apart and the beta pins 64 slide over the narrowing of the second guide rods 58 to take their place on the cylindrical body of the second guide rods 58.

[0081] The force to be exerted on the second centering ring 56 by the first centering ring 32 to obtain a displacement of these two rings to the second crankcase 10 depends on the rigidity of the beta pins 64 and the geometry of the second guide rods 58, notably diameters and slope at the narrowing level. This force can therefore be adapted during the design of the device according to the specifications. The resistance opposing the displacement of the second centering ring 56 could be achieved by means other than those described (notably the beta pins) with the help, for example, of a hydraulic actuator or other. The fact that a predetermined minimum force must be exerted to obtain the displacement of the second centering ring 56 (with the first centering ring 32) allows the shafts to be correctly aligned from the start by aligning the male coupling piece 2 with the female coupling piece 4 before bringing the heads into contact with the thrust clutch.

[0082] When the first head with thrust clutch 16 comes against the second head with thrust clutch 28, Petition 870230040777, dated 05 / 16 / 2023, page 29 / 53 23 / 40 an effort corresponding approximately to the effort exerted on the second centering ring to move it, is also exerted on the moving assembly formed by the intermediate bearing 8 and the female coupling piece 4 that holds the second head with thrust clutch 28. The moving assembly then re-enters the central bore of the second crankcase 10, compressing the first springs 66. These springs are then compressed proportionally to the axial force to which they are subjected, the travel of this moving assembly being limited when the lateral face 48 of the intermediate bearing 8 comes into contact with the second crankcase 10.

[0083] There is little chance that the teeth of the thrust clutches will be flush against each other and engage directly when the system goes from the second position illustrated in Figure 2 to the third position in Figure 3. It is therefore necessary to rotate a shaft to cause the teeth of the thrust clutches to engage with each other. For example, assume that the drive shaft is the one whose end is mounted on the female coupling piece 4. This latter piece is then set in rotation. By means of the bearings 18', the female coupling piece 4 rotates in the intermediate bearing 8, thus actuating the second head with thrust clutch 28. The teeth 24' of the latter then engage with the teeth 24 of the first head with thrust clutch 16 (Figure 4). Indeed, under the effect of the first springs 66, the moving assembly including the movable bearing 8 and the female coupling piece 4 is driven towards the male coupling piece 2.Meanwhile, the second springs 68 rest on the support washers 60 and exert tension on the second guide rods 58 such that... Petition 870230040777, dated 05 / 16 / 2023, page 30 / 53 24 / 40 second centering ring 56 remains in contact with the first centering ring 32.

[0084] In the position illustrated in figure 4, the drive shaft, whose end is mounted on the female coupling piece 4, drives the female coupling piece 4 which rotates in the intermediate bearing 8 and drives, by means of the heads with thrust clutch, the male coupling piece 2 which is mounted on one end of a shaft that is thus driven in rotation. Under the effect notably of the tension exerted by the first springs 66, the connection between the thrust clutches is maintained.

[0085] Figures 7 to 17 illustrate the integration of this system into a hitch device and more precisely, by way of non-limiting illustrative example, into a hitch device for an agricultural tool to an agricultural tractor.

[0086] Figure 7 illustrates an agricultural tool 100 fitted with an engaged frame 102 and a drive shaft 104 fitted with a cardan shaft 106.

[0087] The agricultural tool 100 can be of any type and is not detailed here.

[0088] The engaged frame 102 comprises a lower crossbar 108, an upper crossbar 110 and two uprights 112 connecting the lower crossbar 108 to the upper crossbar 110.

[0089] On one side of the cardan shaft 106 is the drive shaft 104 which is part of the agricultural tool and is provided by its maker for the drive of the tool. On the other side of the cardan shaft 106 is a bushing 114 which is adapted to cooperate with the male coupling piece 2.

[0090] Note in figure 7 the presence of two arms Petition 870230040777, dated 05 / 16 / 2023, page 31 / 53 25 / 40 supports 116 that carry a part of the coupling device and more precisely the part of this device comprising notably the first crankcase 6 and the male coupling piece 2. These support arms 116 have free rod-shaped ends that cooperate with the profiled pieces 46. Each of these support arms 116 is pivotally mounted around an axis 126 (figure 20) that extends between the lower crossbar 108 and the upper crossbar 110. Each time elastic means, such as, for example in the illustrated embodiment, gas springs 118, are provided to pre-tension these support arms 116 in a position (figures 7, 16 and 18) in which the ends of the support arms 116 cooperate with the profiled pieces 46 to hold in position a part of the coupling device.As will be explained later in relation to Figure 20, these support arms 116 can also be opened in a position where the free ends of these support arms 116 are moved away from the coupling device.

[0091] Figure 8 schematically shows a rear section of an agricultural tractor 200 with a three-point hitch system classically comprising two lower arms 204 and an upper arm 206 of variable length (formed here by an actuator). This three-point hitch system here bears the inverted U-shaped hitch frame 202 with a base 208 located in an upper position and two legs 210 extending downwards from the base 208. The upper arm 206 (or actuator) is connected to the base 208, approximately in its center, while each of the lower arms 204 is connected to a leg 210, approximately near a free end of the base. Petition 870230040777, dated 05 / 16 / 2023, page 32 / 53 26 / 40 leg 210 corresponding.

[0092] The second crankcase 10 is mounted with the help of the two semi-flanges 72 on its support arranged on the tractor in such a way that a drive shaft, often called a power take-off, is housed in the female coupling piece 4.

[0093] The coupled frame 102 and the coupled frame 202, for example, both have a welded structure. They are adapted to be joined together. It is notably observed that the base 208 (upper) of the coupling frame 202 is in the form of a beam with a roughly square cross-section which has, on its face opposite the legs 210, two centering pins 214. The upper crossbar 110 of the coupled frame 102 is, in turn, in the form of a beam with a cover 120 that projects forward (i.e., towards the coupling frame 202) so as to be able to cover the base 208 of the coupling frame 202. Cylindrical housings 122 corresponding to the centering pins 214 are provided in the cover 120 to receive said centering pins 214.

[0094] Similarly, as can be seen in Figure 8, each leg 210 of the hitch frame 202 has an end plate from which two locking fingers 216 project each time. Correspondingly, the hitched frame 102 has corresponding locking holes 124 at the level of its lower crossbar 108. The two locking fingers 216 corresponding to a leg 210 are mounted on a plate 226 that extends approximately perpendicular to the corresponding leg 210 and protrudes rearward from this leg 210. This plate 226 is Petition 870230040777, dated 05 / 16 / 2023, pp. 33 / 53 27 / 40 mounted slidingly so as to be able to move away from / closer to the end of leg 210. An actuator (concealed inside leg 210) allows the displacement of the plate 226 relative to the corresponding leg 210 to be controlled. The plate 226 is connected to its control actuator by at least one rod 228 mounted slidingly relative to leg 210 and pre-tensioned by a spring 230 in the position of the plate 226 approximated to the free end of the corresponding leg 210.

[0095] Figure 9 shows a side view of the rear part of an agricultural tractor equipped, on one side, with the hitch frame 202 and, on the other side, with a part of the coupling system of figures 1 to 6 mounted on its support. It also shows a schematic agricultural tool that is equipped, on one side, with the hitched frame 102 and, on the other side, with the part of the coupling system of figures 1 to 6 that complements the part mounted on the tractor.

[0096] In figure 9, the agricultural tool 100 is placed face to face with the rear of the agricultural tractor 200 without any contact between the two.

[0097] The agricultural tractor 200 being motorized, the agricultural implement 100 remains in place and the agricultural tractor 200 reverses to approach the agricultural implement 200. During this maneuver, the tractor driver acts on a hydraulic system of the agricultural tractor 200 in order to tilt it with the help of the upper arm 206, which is of variable length, so that the hitch frame 202 makes an angle of ten degrees with the hitched frame 102. The driver also maneuvers so that the base 208 of the hitch frame 202 with its centering pins Petition 870230040777, dated 05 / 16 / 2023, page 34 / 53 28 / 40 214 comes under the hood 120 of the hitched frame 102, centering the hitched frame 202 in relation to the hitched frame 102. The agricultural tool 100 being "free", centering is carried out automatically thanks in particular to the conical shape of the centering pins 214.

[0098] Figure 10 shows the coupling frame 202 inclined relative to the engaged frame 102, the centering pins 214 beginning to penetrate the corresponding cylindrical housings 122 of the engaged frame 102.

[0099] In this position, the two parts of the coupling device are brought close together and a space of one to ten centimeters separates them.

[00100] From the position illustrated in Figure 10, in which the agricultural tool 100 rests on the ground, the three-point lifting system is raised. It can raise the agricultural tool 100 as illustrated in Figure 11, but if the agricultural tool 100 is equipped with deflection suspension, the wheels of the agricultural tool 100 remain on the ground and only the chassis of the agricultural tool 100 is driven upwards. During this movement, the engaged frame 102 comes into contact with the hitch frame and the locking fingers 216 come into position facing the locking holes 124 without entering the latter.

[00101] In this position, the two frames are in a coupled but not locked position, and the power take-off does not yet drive the drive shaft 104 of the agricultural tool 100.

[00102] It can be noted in the detail view of figure 11 that the 200 agricultural tractor has a guide device that can accommodate a side guide plate (it can accommodate a second one, symmetrical to the first in relation to the Petition 870230040777, dated 05 / 16 / 2023, pp. 35 / 53 29 / 40 second crankcase 10) which has a rounded upper edge 218 forming a guide surface. This upper edge 218 is intended to cooperate with a finger 42 that projects from one side of the first crankcase 6 as will be explained below. This device also includes an arm 220 articulated around a transverse axis 222. In figure 11, the arm 220 is in an elevated position and its end is close to the corresponding finger 42.

[00103] Above each guide side plate 234, a locking device may be found. Figures 22 to 25 illustrate an example of a locking device. As illustrated in Figures 22 to 24, each locking device has, for example, two claws arranged, each approximately in the same plane as the corresponding guide side plate 234, that is, in a roughly vertical and longitudinal plane (approximately parallel to a longitudinal axis of the tractor). A lower claw 236 is mounted fixed to the structure of the agricultural tractor 200 while an upper claw 238 is mounted articulated. A housing is defined between the two claws. By pivoting, the upper claw 238 opens and closes access to this housing. A tension spring 240 pre-tensions the upper claw 238 in a closed position and thus forms a tongue.

[00104] The arms 220 can then be actuated with the aid of each a locking actuator 244 (figure 25) to move to their lowered position illustrated in figure 12. The two arms 220 preferably have a common transverse axis 222 and a single locking actuator 244 controls the movement of the arms 220. This locking actuator 244 is preferably a double-acting actuator. Petition 870230040777, dated 05 / 16 / 2023, pages 36 / 53 30 / 40

[00105] In a preferred embodiment, the guide side plate 234 and the lower claw 236 are mounted directly on the support 74. As can be seen in figures 16 and 17, this support 74 may have a general U-shape, with a vertical base and two vertical side plates. Each of these vertical side plates is then advantageously cut out to form, on one side, the guide side plate 234 with its upper edge 218 and, on the other side, the lower claw 236. Now it is considered to align the two parts of the coupling device. The part of the coupling connected to the agricultural tool 100 (figures 11 and 12) is in a higher position than the part of the coupling connected to the agricultural tractor 200. The arms 220 are then brought down (figure 12).The entire part of the coupling device connected to the agricultural tool 100 is then lowered by lowering the two frames (engaged frame 102 and engagement frame 202) acting on the actuator that forms the upper arm 206. In this movement, the part of the coupling connected to the agricultural tool 100 is lowered and each of the fingers 42 comes to rest on the corresponding arm 220 (only a single arm 220 and a single finger 42 are visible in the figures) as illustrated in figure 13.

[00106] The view in Figure 22 corresponds roughly to the position illustrated in Figure 13. The two parts of the coupling device are face to face, at a distance ranging from a few centimeters to a few tens of centimeters.

[00107] The assembly formed by the agricultural tool 100, the hitched frame 102 and the hitch frame 202 continues its downward movement with the help of the actuator that forms the Petition 870230040777, dated 05 / 16 / 2023, pages 37 / 53 31 / 40 upper arm 206 while in parallel the arms 220 rise with the help of the locking actuator 244. In this last movement (figure 13 to figure 14), the arms 220 act on the fingers 42 to bring the part of the coupling device connected to the tool closer to the part of the coupling device connected to the tractor. The upper edge 218 of each guide side plate 234 participates in guiding the fingers 42 in the last phase of approach, before the part of the coupling device connected to the tool comes into contact with the part of the coupling device connected to the tractor. The upper edge 218 thus guides the corresponding finger 42 to the bottom of a housing that here presents the form of a notch formed in the guide side plate 234. When the finger 42 reaches the corresponding notch, the arm 220 closes the notch and the finger is then locked into the bottom of the notch.The end of travel of finger 42 is not defined by the bottom of the notch, but rather by the contact between the thrust clutches. Thus, progressively the coupling device reaches the position illustrated in Figure 2, and then the coupling device of two shafts from Figures 1 to 6 passes in order to the positions illustrated in Figures 2 to 4 and discussed above. Typically, a drive shaft of an agricultural tool is of variable length. Thus, when the arms 220 are actuated and cooperate with the fingers 42, the part of the coupling device associated with the agricultural tool 100 moves towards the agricultural tractor 200. In this movement, a guide is made by the sliding of the ends of the support arms 116 in the profiled parts 46 in which they are housed. It can be seen by comparing Figures 13 and 14a. Petition 870230040777, dated 05 / 16 / 2023, pages 38 / 53 32 / 40 difference between the relative position of a support arm 116 and its corresponding profiled part 46. During this movement, the drive shaft of the agricultural tractor 200 is set in rotation to drive the female coupling piece and allow the coupling of the two shafts to be completed.

[00108] A locking between the two parts of the coupling device can be achieved thanks to the locking devices. Each arm 220 (in theory, only one may be sufficient) has a locking pin 242 intended to cooperate with the corresponding locking device. Thus, parallel to the movement illustrated in figures 2 to 4, each locking pin 242 is guided to the claws. Each locking pin 242 is positioned on the corresponding arm 220 in such a way that during its course it comes to rest on the corresponding upper claw 238 so as to move to meet the pre-tension exerted by the corresponding spring 240. At the end of the movement, the locking pin 242 is in the housing defined between the lower claw 236 and the upper claw 238 which act as a tongue thanks to the action of the spring 240 and commands the closing of the access to the housing provided that the locking pin 242 has taken its place in the latter.

[00109] To achieve the locking described above, it is planned to perform a supplementary locking mechanism to better lock an additional degree of freedom between the part of the coupling device mounted on the tractor and that mounted on the tool, namely a degree of freedom corresponding to a rotation around an axis perpendicular to the plane of the figures, for example around fingers 42. For this purpose, it is proposed to equip the part of Petition 870230040777, dated 05 / 16 / 2023, pages 39 / 53 33 / 40 coupling device on the tool side of at least one anti-joint pin 246. The latter may also be held by an arm 220. In the embodiment proposed by way of illustration and not limitation in the drawing, an anti-joint pin 246 is arranged parallel to each finger 42 on each branch 38 of the support 34. Preferably, two anti-joint pins 246 are then provided on the support 34, arranged symmetrically with respect to a median plane. Each anti-joint pin 246 then comes into contact with the corresponding arm 220 in the locked position of the locking device, as illustrated in figure 24. In the latter figure, the support 74, not shown in figure 23, is present, but the tension springs 240 have been hidden to show an anti-joint pin 246 in the locked position.

[00110] Once the coupling of the trees is carried out, the two frames are locked and the support arms 116 can be pivoted and moved away from the coupling device as illustrated in figure 15 showing the system in the engaged and coupled position. In effect, once the two trees are coupled and gripping each other, it is no longer necessary to come and support the tree on the side of the agricultural tool 100. It is even preferable to leave it free so that it can work without tension. Furthermore, the engaged frame 102 and the engagement frame are locked by making the locking fingers 216 cooperate with the corresponding locking holes 124. An action of each actuator 224 allows acting on the corresponding plate 226 and making the locking fingers 216 penetrate the corresponding locking holes 124.

[00111] Figure 20 illustrates a mechanism allowing Petition 870230040777, dated 05 / 16 / 2023, pages 40 / 53 34 / 40 pivoting the support arms 116. As indicated above, these support arms 116 are mounted pivotally around an axis 126 that extends approximately vertically in "normal" use of the device. In the preferred embodiment illustrated here, the support arms 116 are fitted with a plate that is fixed onto a perforated plate 128 which is integral (for example welded) to the axis 126, which extends in a plane containing the pivot axis of the corresponding support arm 116 and which has numerous fixing holes allowing the plate of a support arm 116 to be positioned in different positions relative to the axis 126. This last feature allows, for the same attached frame, adaptation to numerous different agricultural tools. It should be noted that the gas springs 118 are connected at one of their ends to this perforated plate 128.

[00112] At its lower end, the perforated plate 128 is bent each time, thus forming an inclined plane 130 in relation to the rest of the perforated plate 128. In figure 20, a roller 132 is visible below this inclined plane. The latter is mounted at the end of an arm 134 that passes through the lower crossbar 108 and projects beyond it. This arm 134 is mounted parallel to the axis 126. The roller 132 and the inclined plane are arranged in such a way that when the roller 132 is pushed (upwards) towards the perforated plate 128 (or towards the upper crossbar 110), then the perforated plate 128 pivots against the tension exerted by the gas springs 118 so as to move the support arm 116 away.

[00113] It is advantageously anticipated that the opening action Petition 870230040777, dated 05 / 16 / 2023, pages 41 / 53 35 / 40 of the support arms 116 is performed simultaneously with the locking of the engaged frame 102 onto the engagement frame 202. To achieve this, it is proposed, by way of illustration and not limitation, that each plate 226 bearing locking fingers 216 has an extension 232. As illustrated in Figure 21, which is a bottom view and enlarged scale detail of the two assembled frames, this extension 232 is positioned under the arm 134 which bears the roller 132. Thus, when the locking of the engaged frame 102 with the engagement frame 202 is performed, acting on the plate 226 to insert the locking fingers 216 into the locking holes 124, the extension 232 acts on the arm 134 which, by means of the roller 132, acts on the inclined plane 130 to open the support arm. 116 corresponding. In case of a hydraulic problem, springs 230 maintain plate 226 in its position corresponding to the locking of the frames, which is the safety position.

[00114] Figures 16 to 19 are complementary figures allowing for a better understanding of the structure of the mechanism described above. Figures 16 and 18 correspond to the position illustrated in Figure 14 (support arms 116 cooperating with the profiled parts 46) while Figures 17 and 19 correspond to the position illustrated in Figure 15 (support arms 116 open).

[00115] Figures 16 and 17 are viewed from above. For example, support 74 can be seen there, onto which the part of the coupling device connected to the agricultural tractor 200 is fixed. This support 74, in the illustrated embodiment, is presented in the form of a U-shaped profiled piece with a transverse vertical base (tractor side) that receives the semi-flanges 72. Petition 870230040777, dated 05 / 16 / 2023, pages 42 / 53 36 / 40 and with two lateral (vertical) branches that extend to the agricultural tool 202 and which can, for example, serve as support (and possibly integrate in part as indicated in the preferred embodiment described for the guide devices cooperating with the fingers 42 as well as the locking devices with each, a lower claw 236, an upper claw 238 and a spring 240.

[00116] In short, the coupling of a tool (in the illustrated example, agricultural tool 100) to a machine (in the illustrated example, agricultural tractor 200) can be carried out as follows.

[00117] Initially, the tool is equipped with a frame called the engaged frame, while the machine is equipped with another frame called the engagement frame. The engaged frame is equipped with means that allow it to become attached to the engagement frame.

[00118] In addition, the tool is equipped with a shaft, called the driven shaft, intended to be driven by the machine in order to provide it with the energy (or power) to enable it to perform its function. The machine is in turn equipped with an engine comprising an output shaft, called a power take-off, on an agricultural tractor.

[00119] The driven tool spindle is fitted with a part of a coupling device and the output spindle of the machine is fitted with a second part of said coupling device.

[00120] The part of the coupling device associated with the driven spindle of the tool comprises an element, in one or more parts, which is mounted in such a way that it is integral with the driven spindle (for example, mounting with Petition 870230040777, dated 05 / 16 / 2023, pages 43 / 53 37 / 40 grooves and / or pin) and which is equipped with a tooth and groove system called the first thrust clutch. This element is pivotally mounted in a first crankcase.

[00121] Similarly, the part of the coupling device associated with the machine's output shaft comprises an element, in one or more pieces, which is mounted in such a way that it is integral with the output shaft and which is equipped with a system of teeth and grooves, or second thrust clutch, intended to cooperate with the first thrust clutch in such a way that the first thrust clutch actuates the second thrust clutch, preferably with as little play as possible. Such a thrust clutch system allows almost 100% of the power available on the output shaft to be transmitted to the driven shaft if the thrust clutches are well matched to each other. Here, the element with the second thrust clutch is pivotally mounted in a bearing called an intermediate bearing which in turn is mounted in a second housing, fixed on the machine, so as to be able to slide relative to said second housing in a manner approximately parallel to the output shaft.

[00122] The first crankcase and the intermediate bearing are also fitted with centering devices, preferably conical centering devices.

[00123] To couple the (non-motorized) tool to the (motorized) machine, an operator maneuvers the machine to bring it closer to the tool. The hitch frame is mounted movably on the machine, and the operator brings the hitch frame close to the attached frame, adapting the position (height from the ground and inclination relative to the vertical, notably) of the hitch frame to that of the attached frame. Petition 870230040777, dated 05 / 16 / 2023, pages 44 / 53 38 / 40 Regarding the engaged frame, the part of the coupling device carried by the tool is held in a predetermined position by a retaining and supporting device such that this part of the coupling device is sensibly facing the other part of the coupling device when the engaged frame is facing the engagement frame in a corresponding position approximately (for example, some - from 0 to 20 centimeters).

[00124] The operator maneuvers to engage the coupling frame to the coupling frame. The two parts of the coupling device approach each other. They are arranged on the machine and the tool in such a way that the conical parts of the first crankcase and the intermediate bearing come into contact with each other during this maneuver. In this way, a self-centering of these two coupling parts is achieved, leading to the first thrust clutch facing the second thrust clutch. An approach system, for example with at least one arm mounted on one part of the device cooperating with a finger mounted on the other part of the device, possibly hydraulically controlled, is used to finalize the centering of the conical parts in relation to each other. The two thrust clutches are then initially aligned without coming into contact with each other.When a sufficient force (predetermined based on the system's dimensions) is exerted between the two conical parts towards the machine, the intermediate bearing moves towards the machine in sliding relative to the second crankcase, thus allowing the teeth of the first thrust clutch to come into contact with the teeth of the second. Petition 870230040777, dated 05 / 16 / 2023, pages 45 / 53 39 / 40 Thrust clutch. There is little chance here that the teeth of one thrust clutch will coincide with the grooves of the other thrust clutch, but this can happen. To engage the thrust clutches, the machine's output shaft is driven in rotation. Pre-tensioning means push the intermediate bearing towards the tool, although during rotation, the two thrust clutches engage with each other. The shafts are coupled. The frames can then be locked between them. Preferably, the retaining and support means of the part of the coupling device associated with the tool are moved in such a way that the first housing can move freely.

[00125] As described above, in parallel with this coupling operation, a locking can be performed automatically. After unlocking, uncoupling is performed by operating in reverse.

[00126] To perform the unlocking, it is sufficient to open each upper claw 238. Here too, as for the arms 220, it is provided to make the two upper claws 238 solidary by connecting them by a connecting shaft 250 (figure 25). An unlocking actuator 248 is then provided to act on one upper claw 238 to open the latter. By means of the connecting shaft 250, the unlocking actuator 248 then also commands the opening of the other upper claw 238.

[00127] The presented hitch device allows a tractor driver to hitch an agricultural implement without having to leave the tractor's control position. The hitching and mechanical coupling of the agricultural implement can be done simply and safely. No manual intervention is required at the level of the agricultural implement. Petition 870230040777, dated 05 / 16 / 2023, pages 46 / 53 40 / 40 100 and / or the hitch of the agricultural tractor 200 needs to be done.

[00128] Similarly, it is possible to remove the agricultural tool attached to the agricultural tractor without manual intervention, thus limiting any risk of injury.

[00129] The coupling system allows for perfect transmission of power from the tractor to the tool. Thanks to the perfect alignment of the shafts, no wear or parasitic stress is exerted on the system.

[00130] Once engaged, the tool's operation is not altered in any way, and everything proceeds as if the tool had been attached directly to the tractor's three-point hitch system.

[00131] Naturally, the present invention is not limited to the preferred embodiment described and illustrated in the drawing and the variants mentioned. It also covers all embodiments within the reach of a person skilled in the art within the framework of the claims below. Petition 870230040777, dated 05 / 16 / 2023, pages 47 / 53

Claims

1 / 5 CLAIMS 1. A coupling device for two shafts end-to-end, comprising a pair of thrust clutches (16, 28), each thrust clutch being shaped so as to be able to become integral with one end of the shaft to be coupled and the two thrust clutches (16, 28) being of complementary shapes, characterized in that a first thrust clutch (16) is pivoting mounted in a first crankcase (6), wherein a second thrust clutch (28) is pivoting mounted in an intermediate bearing (8), wherein the intermediate bearing (8) is sliding mounted in a second crankcase (10), the intermediate bearing (8) being able to slide relative to the second crankcase (10) in a direction parallel to the two shafts to be coupled, said longitudinal direction, and wherein the intermediate bearing (8) is elastically pre-tensioned towards the first crankcase (6).

2. Coupling device, according to claim 1, characterized in that the first crankcase (6) has a first conical surface (32) facing the second crankcase (10), wherein the second crankcase (10) has a second conical surface (56) facing the first crankcase (6), the two conical surfaces being of complementary shapes so as to achieve an alignment of the two shafts, wherein the first conical surface (32) or the second conical surface (56) is mounted sliding longitudinally in relation to the crankcase that has it, and wherein the sliding conical surface (56) is elastically pre-tensioned towards the other conical surface (32).

3. Coupling device, according to claim 2, characterized in that the sliding conical surface (56) and the corresponding crankcase (10) are provided with retarding means (58, 64) such that the displacement of said conical surface (56) cannot be initiated except when a predefined minimum tension in the longitudinal direction is exerted on said conical surface (56) to the crankcase (10) that houses it.

4. Coupling device, according to claim 3, characterized in that the retarding means comprise at least one guide rod (58) integral with the sliding conical surface (56), wherein said guide rod (58) comprises a contracted section zone capable of sliding in a perforation within the corresponding crankcase (10), wherein the corresponding crankcase (10) comprises a slot (62) extending transversely relative to the perforation receiving at least partially the guide rod (58) and intercepting said perforation, and wherein an elastic element (64) having two branches is housed in said slot (62), the contracted section being disposed between the two branches of the elastic element (64).

5. Coupling device, according to any one of claims 1 to 4, characterized in that it further comprises connecting means, said means comprising on either side of a thrust clutch each time a projection (42) integral with the corresponding crankcase (6), the other crankcase (10) bearing, on one side each time guide means (218) for carrying a projection (42) into a housing and, on the other side, a hook (220) mounted pivoting around a transverse axis (222) between a said open position allowing the projection (42) to enter and exit its housing and a said closed position in which the hook (220) can hold the projection (42) in its housing preventing it from exiting therefrom.

6. Coupling device, according to claim 5, characterized in that the two hooks (220) are mounted pivotally on a common transverse axis (222) and in that the movement of the hooks (220) is controlled by a double-acting hydraulic actuator (244).

7. Coupling device, according to claim 5 or 6, characterized in that at least one hook (220) bears a locking pin (242) intended to cooperate with a pair of claws (236, 238), said claws being carried by the same housing (10) as that which bears the hooks (220) and being arranged in such a way that the locking pin (242) is between the claws (236, 238) when the corresponding hook (220) is in the closed position.

8. Coupling device, according to claim 7, characterized in that for each pair of claws, one claw (236) is fixed and the other (238) is movable, wherein a spring (240) pretensions the movable claw (238) to the fixed claw (236) and wherein an actuator (248) allows it to act against the spring (240) to move the movable claw (238) away from the fixed claw (236).

9. Attachment device for an agricultural tool (100), on a lifting system of an agricultural tractor (200), equipped with an output drive shaft, comprising: - a first frame called the attachment frame (202) and equipped with fastening devices allowing attachment to the lifting system of the machine, Petition 870240077125, dated 09 / 09 / 2024, page.17 / 19 4 / 5 - a second frame called the engaged frame (102) and provided with fastening devices allowing attachment to the tool, each between the engagement frame (202) and the engaged frame (102) having a joining face, said joining faces being adapted to allow the pairing of the engaged frame with the engagement frame, - means of relative locking of the engaged frame (102) on the engagement frame (202) in the paired position, characterized in that: said engagement device further comprises a coupling device for two shafts end to end as defined in any of claims 1 to 8, said coupling device being intended to be mounted between the output drive shaft of the machine and a driven shaft of the tool.

10. Engagement device, according to claim 9, characterized in that the engaged frame (102) comprises two arms (116) mounted pivoting between an approximate position in which the free ends of the arms carry the first crankcase (6) of the coupling device and an open position in which the arms (116) are spread apart and their free ends are away from the first crankcase (6).

11. Coupling device, according to claim 9 or 10, characterized in that the coupling frame (202) has a welded structure comprising a crossbar (208) from which two legs (210) extend on the same side of said crossbar and in which the coupled frame (102) has a welded structure comprising an upper crossbar (110), a lower crossbar (108) and two uprights. Petition 870240077125, dated 09 / 09 / 2024, page. 18 / 19 5 / 5 (112) connecting the ends of the lower crossbar to the ends of the upper crossbar, wherein the crossbar (208) of the hitch frame (202) has at least two centering pins (214), wherein the upper crossbar (110) of the hitched frame (102) comprises a cover (120) extending into the hitch frame (202) and having at least two housings (122) each intended to receive a centering pin (214).

12. Engagement device, according to claim 11, characterized in that each leg (210) of the engagement frame (202) has at its free end a plate on which at least one locking finger (216) is disposed and in that the lower crossbar (108) of the engaged frame comprises locking holes (124) arranged in such a way as to be able to accommodate the locking fingers.

13. Engagement device, according to claim 10 or 12, characterized in that it comprises actuation means for the pivoting mounted arms (116), said actuation means cooperating with the plate on which at least one locking finger is disposed, such that in the locking position of the frame engaged on the engagement frame, the arms are in their open position.

14. Coupling device, according to any one of claims 9 to 12, characterized in that the first crankcase (6) of the coupling device is mounted on the side of the engaged frame (102) while the second crankcase (10) is mounted on the side of the coupling frame (202). Petition 870240077125, dated 09 / 09 / 2024, p. 19 / 19

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