Device for coupling two shafts, and hitching device with that coupling device

Abstract

To simplify existing systems while ensuring semi-automatic coupling and perfect transmission of power from a device to an implement under all circumstances.SOLUTION: A device for coupling two shafts comprises a pair of dog clutch members (16, 28). Each dog clutch member is configured to be able to be secured to an end of a shaft to be coupled, and the two dog clutch members (16, 28) have complementary shapes. The first dog clutch member (16) is pivotably attached into a first casing (6). The second dog clutch member (28) is pivotably attached to an intermediate bearing (8). The intermediate bearing (8) is slidably attached into a second casing (10) to be fixed. The intermediate bearing (8) is able to slide relative to the second casing (10) in a longitudinal direction parallel to the two shafts to be coupled. The intermediate bearing (8) is elastically prestressed in the direction of the first casing (6).SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a device for connecting two shafts, more particularly to the connection of a driving shaft and a driven shaft, and also to a hitch device comprising a device for connecting two shafts.

[0002] As will be explained in more detail below, the technical problem of the device is to semi-automatically couple the driven shaft to the driving shaft when connecting an implement with a receiving shaft, such as an agricultural implement, to an apparatus such as an agricultural tractor with a driving shaft, which is called a power take-off in the agricultural field. The semi-dynamic coupling allows the operator of the device to perform the coupling operation from the cab of the device while maintaining a distance from the coupling means. [Background technology]

[0003] French Patent No. 2 995 756 and French Patent No. 3 018 029 each relate to a hitch device for connecting an agricultural implement to an apparatus, such as an agricultural tractor, to which a hitched frame is attached and to which a towing frame is attached.

[0004] These documents show means for semi-automatically connecting an instrument to a device, said connection being carried out by the operator of said device without him leaving the cab.

[0005] EP 2098741 A1 relates to a decoupling / disconnecting assembly for decoupling a generator from a gearbox, comprising a first inner ball screw with an angled thread on its outer surface, surrounding a rotating generator drive shaft and rotating by engaging with the drive shaft. The inner ball screw is attached to an engagement member having undercut-formed and interlockable teeth engaged with teeth of an engagement member of the gearbox. An outer ball screw surrounds the inner ball screw and normally rotates together with the inner ball screw. A helical ball track is formed between the inner and outer ball screws. A brake is provided for slowing down or stopping the rotation of the outer ball screw, and the inner ball screw can rotate relative to the outer ball screw along the ball track and slide axially away from the gearbox. This allows the generator to be removed from the drive shaft of the gearbox. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] French Patent No. 2995756 [Patent Document 2] French Patent No. 3018029 [Patent Document 3] European Patent Application Publication No. 2098741 Summary of the Invention [Problem to be solved by the invention]

[0007] The object of the present invention is in particular to improve the existing system in such a way as to simplify it while still being able to ensure semi-automatic coupling and perfect transmission of power from the device to the tool under all circumstances. [Means for solving the problem]

[0008] The present invention aims to solve the above-mentioned problems.

[0009] The device of the present invention is a coupling device for connecting the ends of two shafts, one pair of shafts. Each dog clutch member is configured to be securable to an end of a shaft to be coupled thereto, and the two dog clutch members have complementary shapes.

[0010] According to the invention, a first dog clutch member is journaled in a first casing. A second dog clutch member is journaled in an intermediate bearing. The intermediate bearing is slidably mounted in a fixed second casing. The intermediate bearing is slidable relative to the second casing in a longitudinal direction parallel to the two shafts to be connected. The intermediate bearing is elastically preloaded in the direction of the first casing.

[0011] Such an arrangement allows the coupling of two shafts, each rotatably mounted within a respective casing. Each shaft is associated with a dog clutch member. The shafts are aligned and pressed towards each other upon coupling. The dog clutch members are unlikely to be oriented relative to each other in such a way that their teeth directly engage. The relative orientation of the dog clutch members is obtained by rotating one shaft relative to the other shaft, allowing translational engagement. The arrangement allows one dog clutch member to move axially relative to the other dog clutch member, the elastic preload ensuring proper engagement of the dog clutch members.

[0012] As used herein, the term "dog clutch member" refers to a mechanical coupling means having teeth and grooves that can achieve a direct coupling with a complementary shaped coupling means of the same type.

[0013] To facilitate alignment of these shafts, for example, the first casing has a first conical surface facing the second casing and the second casing has a second conical surface facing the first casing, and to achieve alignment of the two shafts, the two conical surfaces have complementary shapes, and the first conical surface or the second conical surface is mounted to slide longitudinally relative to the casing on which it is provided, and the sliding conical surface is elastically preloaded in the direction of the other conical surface.

[0014] In this embodiment, to ensure proper alignment before the engagement of the dog clutch members, the sliding conical surfaces and the corresponding casing are provided with delay means, the movement of the conical surfaces being initiated only when a predetermined minimum longitudinal load is applied to the conical surfaces towards the casing. Here, the corresponding male and female conical surfaces, centering elements having complementary shapes, fit together to allow a perfect prepositioning of the connecting members constituted by the dog clutch members, whereby the connecting members are accurately positioned relative to each other and mechanical damage thereto is avoided. Preferably, a stage is provided in which the dog clutch members are perfectly aligned but not abutting each other.

[0015] In a preferred embodiment, the delay means comprises at least one guide rod integral with the sliding conical surface, the guide rod having a narrowed cross-sectional area slidable within an inner hole of the corresponding casing, the corresponding casing having a slot extending transversely to and intersecting the hole for at least partially receiving the guide rod, a resilient member having two arms (e.g., an R-clip, as a non-limiting example) received in the slot, the narrowed cross-sectional area being disposed between the two arms of the resilient member (e.g., an R-clip).

[0016] Those skilled in the art will readily recognize other means for achieving the delay function described above. This function may also be performed, for example, by one or more resiliently preloaded latches. In these examples, this function is performed automatically, mechanically, although It can also be controlled and executed by an actuator, hydraulic or otherwise. This delay function is advantageous in that it guarantees a preposition of the coupling members (dog clutch members) and the realization of a clutch without risk of breakage.

[0017] In a preferred embodiment of such a coupling device, the coupling device further comprises connecting and locking means, the means comprising a protrusion on either side of the dog clutch member integral with the corresponding casing, the other casing comprising guide means for moving the protrusion towards the housing and a hook arranged to pivot about a transverse axis between an open position allowing the protrusion to enter and exit the housing and a closed position preventing the protrusion from exiting the housing and retaining the protrusion within the housing.

[0018] In this embodiment, the two hooks are mounted to pivot about a common transverse axis, the movement of the hooks being controlled by a double-acting hydraulic cylinder; and / or At least one of the two hooks is provided with a locking pin which cooperates with a pair of jaws which are provided in the same casing as the hook and which are arranged such that the locking pin is located between the jaws when the corresponding hook is in the closed position.

[0019] When the jaws are provided, for example, each of the pair of jaws may comprise a fixed jaw and a movable jaw, a return spring may apply a preload to the movable jaw towards the fixed jaw, and a cylinder may act in the opposite manner to the return spring, enabling the movable jaw to move away from the fixed jaw.

[0020] According to another aspect of the present invention, there is provided a hitch device for connecting an implement such as an agricultural implement to a lifting mechanism of a device such as an agricultural tractor having a drive output shaft. The hitch device includes a mounting member enabling attachment to the lifting mechanism of the device, a first frame which is a towing frame, and a mounting member enabling attachment to the implement, a second frame which is a towed frame, and is provided with the towing frame and the towed frame each have a joint surface, and these joint surfaces are configured to enable pairing of the towed frame with the towing frame, and means for relatively locking the towed frame to the towing frame at the paired position. In particular, the hitch device further includes a connecting device for connecting the ends of the two shafts of the present invention, and the connecting device is mounted between the drive output shaft of the device and the driven shaft of the implement.

[0021] In such a hitch device, the towed frame includes, for example, two arms, and the two arms are attached so as to pivot between a closed position where their free ends hold the first casing of the connecting device and an open position where the arms are separated and their free ends are separated from the first casing.

[0022] In a preferred embodiment of this hitch device, the towing frame has a joint structure including a cross member with two legs extending from the same side. The towed frame has a joint structure including an upper cross member, a lower cross member, and two upright members connecting the ends of the lower cross member to the ends of the upper cross member. The cross member of the towing frame has at least two centering pins, and the upper cross member of the towed frame has a cup extending towards the towing frame and at least two housings configured to receive the centering pins respectively.

[0023] In this embodiment, a plate having at least one locking finger arranged thereon is provided at the free end of each leg of the towing frame, and the lower cross member of the towed frame is provided with a locking hole arranged to receive the locking finger.

[0024] According to a preferred embodiment, the hitch device comprises, for example, actuation means for actuating the pivotally mounted arm, which actuating means cooperates with the plate on which at least one locking finger is arranged and places the arm in an open position when the towed frame is in the locking position on the towing frame.

[0025] For the hitch arrangement described herein, for example, a first casing of the hitch arrangement is attached to a side of the towed frame and a second casing is attached to a side of the towing frame. [Brief description of the drawings]

[0026] Other aspects, objects and advantages of the present invention will become apparent from the following detailed description, and the present invention will be better understood with reference to the accompanying drawings, in which:

[0027] [Figure 1] FIG. 1 is a perspective view of a device for connecting two shafts. [Diagram 2] FIG. 2 is a longitudinal section of the coupling device in a first position. [Diagram 3] FIG. 3 is a longitudinal section of the coupling device in a second position. [Figure 4] FIG. 4 is a longitudinal section of the coupling device in a third position. [Diagram 5] FIG. 5 is a detailed cross-sectional view of the first position shown in FIG. [Figure 6] FIG. 6 is another detailed cross-sectional view of the first position shown in FIG. [Figure 7]FIG. 7 shows a schematic diagram of an agricultural implement comprising a trailer frame and part of the coupling device shown in FIG. [Figure 8] FIG. 8 shows a schematic view of the rear of an agricultural tractor equipped with a towing frame and part of the coupling device shown in FIG. [Figure 9] FIG. 9 is a side view of the rear of the agricultural tractor shown in FIG. 8 facing the agricultural implement shown in FIG. 7 prior to connection. [Figure 10] FIG. 10 shows the first step of connecting the implement shown in FIG. 7 to the rear of the tractor shown in FIG. [Figure 11] FIG. 11 shows the second stage of connecting the implement shown in FIG. 7 to the rear of the tractor shown in FIG. 8 with a detailed view of part of the coupling arrangement. [Figure 12] FIG. 12 shows a third stage of connecting the implement shown in FIG. 7 to the rear of the tractor shown in FIG. 8, with a detailed view of part of the coupling device. [Figure 13] FIG. 13 shows a fourth stage of connecting the implement shown in FIG. 7 to the rear of the tractor shown in FIG. 8, with a detailed view of part of the coupling device. [Figure 14] FIG. 14 shows a fifth stage in connecting the implement shown in FIG. 7 to the rear of the tractor shown in FIG. 8, with a detailed view of part of the coupling arrangement. [Figure 15] FIG. 15 shows the implement shown in FIG. 7 in a connected position to the rear of the tractor shown in FIG. 8, with a detailed view of part of the coupling arrangement. [Figure 16] FIG. 16 is a top view corresponding to FIG. [Figure 17] FIG. 17 is a top view corresponding to FIG. [Figure 18] FIG. 18 is an elevational view of the instrument side of the frame corresponding to FIG. [Figure 19] FIG. 19 is an elevational view of the towed frame shown in FIG. 18 in a position corresponding to that of FIG. [Figure 20] FIG. 20 is an enlarged detailed perspective view of the towed frame. [Figure 21]FIG. 21 is an enlarged detailed view from below of the two assembled frames. [Figure 22] FIG. 22 is a side view of the coupling device shown in FIG. 1 with the locking device in an open position, as mounted on a support. [Figure 23] FIG. 23 is a view similar to FIG. 22, showing the locking device in the closed position, but without the support. [Figure 24] FIG. 24 is a view similar to FIG. 23 showing the locking device with the support shown but the spring omitted. [Diagram 25] FIG. 25 is a rear view of the connecting device shown in FIGS. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] The accompanying drawings and the following description contain elements, most of which are self-explanatory in nature, and therefore are intended to clarify the definitions thereof, as appropriate, as well as to provide a better understanding of the disclosure of the present invention.

[0029] Fig. 1 shows a device for connecting two shafts. Here, the two shafts to be connected are splined shafts each having a male end and a female end. The device shown in Fig. 1 comprises a male connection part 2 for receiving the female end of the shaft, and a female connection part 4 for engaging with the male end of the shaft. Those skilled in the art will understand from the following description that the coupling device can also connect two shafts each having a male end, or two shafts each having a female end.

[0030] The male connection part 2 is mounted by means of a rolling bearing in a first casing 6, and the female connection part 4 is mounted by means of a rolling bearing in an intermediate bearing 8 which is slidably mounted in a second casing 10 which is different from the first casing 6. This construction is shown clearly in figures 2, 3 and 4 which show longitudinal sections of the device shown in figure 1.

[0031] In the following description, longitudinal direction means the direction defined by the connected shafts and male and female connection parts 2, 4.

[0032] The male connection part 2 has a connection end 12 , a solid cylindrical body 14 and a first dog clutch head 16 .

[0033] The connecting end 12 has a shape that matches the end of the shaft to be connected. In this example, the connecting end 12 engages with a female housing, not shown. In the non-limiting illustrated embodiment, the connecting end 12 is in the form of a splined shaft. The connecting end 12 extends from a solid cylindrical body 14. The solid cylindrical body 14 is provided with a pair of rolling bearings 18, the outer circumferential surface of which is machined to receive the rolling bearings 18. The outer circumferential surface of the solid cylindrical body 14 is not described in detail, but includes stops for the rolling bearings, machined surfaces that serve as seats for the rolling bearings 18, a threaded portion that receives a nut 20, and an area that cooperates with a seal 22 to protect the rolling bearings 18.

[0034] The first dog clutch head 16 is constructed as a single piece with the solid cylindrical body 14 and the connecting end 12. In the example shown, the single piece is obtained by machining. The first dog clutch head 16 constitutes the end of the piece opposite the connecting end 12. The first dog clutch head 16 has a larger diameter than the solid cylindrical body 14. The first dog clutch head 16 has a transverse cross section, the outer periphery of which is regularly arranged with teeth 24 projecting from said cross section.

[0035] The female connection portion 4 has a cylindrical body 26 and a second dog clutch head 28. A dog clutch is formed by the dog clutch head 16 and the second dog clutch head 28. A dog clutch is a device for directly connecting two parts or dog clutch members by means of teeth and grooves.

[0036] The tubular cylindrical body 26 has a housing 30 suitable for receiving the end of the shaft to be connected. The shape of the housing 30 must therefore match the shape of the shaft. In the embodiment shown, the housing 30 is adapted to receive a splined shaft, not shown. The outer surface of the tubular cylindrical body 26 is machined to receive a pair of rolling bearings 18'. The outer surface will not be described in detail, but it comprises stops for the rolling bearings, machined surfaces that act as seats for the rolling bearings 18', a threaded portion for receiving the nut 20', and an area that cooperates with the seal 22' to protect the rolling bearings 18'.

[0037] The second dog clutch head 28 is suitable for engagement with the first dog clutch head 16. The diameter of the second dog clutch head 28 corresponds to the diameter of the first dog clutch head 16. The second dog clutch head 28 also has a cross section from which protrudes teeth 24'. The teeth 24' mesh with the teeth 24 of the first dog clutch head 16.

[0038] The first casing 6 is a cylindrical part, and its inner surface is machined to receive the outer ring of the rolling bearing 18. A housing formed in the first casing 6 to receive the rolling bearing 18 is closed at one end by the seal 22. On the opposite side of the seal 22, which is the first dog clutch head 16 side, a seal 22 is provided between the first dog clutch head 16 and the first casing 6.

[0039] In the first dog clutch head 16, the first casing 6 is provided with a first center ring 32 which is a separate member from the first casing 6 in the illustrated embodiment, and the first center ring 32 is screwed to a flange provided on the first casing 6 for the purpose of assembly, near the first dog clutch head 16. This first center ring 32 has a truncated conical outer surface which is coaxial with the first casing 6 and the male connection part 2.

[0040] On the side opposite the first dog clutch head 16, the first casing 6 comprises means for attachment to a support 34. The support 34 consists of several parts. In the embodiment shown, the support 34 consists of a stirrup-shaped part having a base 36 and two arms 38. The base 36 extends transversely to the male connection 2 and serves to attach the support 34 to the first casing 6. A flange 40 attached to the first casing 6 serves to attach the base 36 of the support 34 to the first casing 6. The arms 38 of the stirrup-shaped part extend in the direction of the first dog clutch head 16 perpendicular to the base 36. Each arm 38 comprises a finger 42 which extends from the arm 38 towards the outside of the stirrup, i.e. away from the first casing 6. The two fingers 42 are coaxial with the arm 38 and extend transversely to the male connection 2. Each arm 38 includes a lateral mounting portion 44 extending away from the first casing 6 and longitudinally outwardly. These lateral mounting portions 44 are adapted to an apparatus to which the support 34 and the corresponding male connector 2 are attached. In the illustrated non-limiting exemplary embodiment, each of the lateral mounting portions 44 includes a mounting plate to the outer surface of which a U-shaped portion 46 is fixed. The free ends of the arms of the U-shaped portion 46 are flared and the U-shaped portion 46 is longitudinally disposed.

[0041] As mentioned above, the female connection part 4 is arranged in an intermediate bearing 8. The intermediate bearing 8 is mounted in a fixed second casing 10 so as to be capable of translational movement in the longitudinal direction.

[0042] The intermediate bearing 8 is a cylindrical part, the inner surface of which is machined to receive the outer ring of the rolling bearing 18' to which the female connection part 4 is attached. A housing 30 formed in the intermediate bearing 8 to receive the rolling bearing 18' is closed at one end by a seal 22'. On the opposite side of the seal 22', that is, on the side of the second dog clutch head 28, another seal 22' is provided between the second dog clutch head 28 and the intermediate bearing 8.

[0043] The intermediate bearing 8 further comprises a flange 48 near the second dog clutch head 28. The flange 48 comprises said seal 22'. The flange 48 also comprises a longitudinal hole for enabling guiding of the flange 48 relative to the second casing 10 and a longitudinal hole for the movement of a guide rod, which will be explained below in conjunction with Figures 5 and 6.

[0044] In this specification, it is assumed that the second casing 10 is fixed, and therefore serves as a reference for the relative movements of the various parts described below. The second casing 10 has a generally parallelepiped shape with a longitudinal central hole through which the movable assembly formed by the female connection part 4 and the intermediate bearing 8 slides. Around the central hole, longitudinal blind holes and longitudinal transverse holes are arranged. In the illustrated embodiment, four blind holes and four through holes are provided. All four blind holes are formed in the longitudinal direction and open on the same face (back face) of the second casing 10, and the blind holes are provided at the bottom with longitudinally arranged female screws.

[0045] As mentioned above, the female connection 4 and the intermediate bearing 8 form an assembly that is movable relative to the second casing 10. Guidance is provided by a central bore of the second casing 10. In the illustrated non-limiting embodiment, a cushion 50 is provided between the outer surface of the intermediate bearing 8 and the inner surface of the central bore of the second casing 10, which is disposed between two wiper seals 52.

[0046] Four first guide rods 54 are provided for guiding the mobile assembly, in particular for preventing rotation of the mobile assembly relative to the second casing 10. Referring to FIG. 5, which is an enlarged cross-sectional view of the coupling device in the first position in FIG. 2, the first guide rods 54 are arranged longitudinally. The first guide rods 54 have the form of a screw having a head, a body and a threaded end opposite the head. The threaded end of each first guide rod 54 is screwed into a blind hole in the second casing 10. The body of each first guide rod 54 constitutes a guide column for the flange 48 of the intermediate bearing 8. The head of each first guide rod 54 constitutes a shoulder that acts as a stop for the flange 48, as shown in FIG. 5. The flanges 48 are located between the heads of the first guide rods 54 and the rear surface of the second casing 10 (the surface where the blind holes open), and the maximum movement of the movable assembly is defined by the distance between the heads of each of the first guide rods 54 and the rear surface of the second casing 10, which is shorter than that distance by the thickness of the flanges 48.

[0047] The second casing 10 comprises a second central ring 56 cooperating with the first central ring 32. The first central ring 32 has a conical outer surface, whereas the second central ring 56 has a conical inner surface. These two conical surfaces, more precisely frustoconical surfaces, have the same apex angle so that they can come into contact with each other when engaged.

[0048] 6, the second center ring 56 includes second guide rods 58. In the illustrated embodiment, four similar second guide rods 58 are provided.

[0049] Each second guide rod 58 has a threaded end that engages with a threaded hole formed in the second central ring 56, thereby securing the second guide rods 58 to the second central ring 56. A shoulder on the second guide rods 58 cooperates with a shoulder on a corresponding threaded hole to properly position the second guide rods 58 relative to the second central ring 56.

[0050] Each second guide rod 58 has a cylindrical body which passes through a hole in the intermediate bearing 8, across the flange 48 of the intermediate bearing 8, and into a hole through the second casing 10. From the cylindrical body extends a region of reduced diameter followed by a shoulder, after which the end of the second guide rod 58 returns to a diameter matching that of the cylindrical body. The end of the second guide rod 58 has a central threaded hole which receives a screw to hold a thrust washer 60 in place.

[0051] As shown in Figs. 2 and 6, the second casing 10 can have a slot 62 in the area of ​​the reduced diameter of the second guide rod 58. The slot 62 is used, for example, to allow an R-clip 64 to be inserted into the second guide rod 58. The R-clip is a clip with two elastic arms preloaded towards each other. One arm is substantially straight and the other arm has a concave area between two protruding areas relative to the first arm. Such an R-clip is provided such that the first arm is received in the through hole of the pin and the concave area contacts the outer side of the pin. In the coupling device described herein, one arm of the R-clip passes through one side of the second guide rod 58 and the other arm passes through the other side of the second guide rod 58, with the second guide rod being placed between the two protruding areas of the clip.

[0052] FIG. 6 is a diagram including a spring. The first spring 66 is a coil spring and is arranged around the cylindrical body of the second guide rod 58. Thus, the first spring 66 is supported and guided by the second guide rod 58 and arranged between the flange 48 of the intermediate bearing 8, which is movable, and the second casing 10, which is fixed. The first spring 66 tends to move the flange 48 of the intermediate bearing 8 away from the back surface of the second casing 10. That is, this allows the intermediate bearing 8 and the female connection part 4 to come out of the central hole of the second casing 10. The second spring 68 is accommodated in the hole of the second casing 10. Each of the second springs 68 is attached between a stopper 70 and a thrust washer 60 attached to the end of the second guide rod 58. The second spring 68 tends to pull the second guide rod 58 out of the hole in the second casing, thereby allowing the second center ring 56 to move away from the second casing 10 .

[0053] The second casing 10, as shown, has two lateral grooves formed in two opposing faces, each of which receives a half clamp 72 for attachment to a support 74 shown in Figures 5, 6, 16 and 17.

[0054] The operation of the device for connecting the two shafts will be explained with reference to FIGS.

[0055] As shown in Fig. 9, the male connection part 2 is moved closer to the female connection part 4 from a position where the two connection parts are separated from each other. Note that the second casing 10 is fixed, and the movable assembly including the female connection part 4 and the intermediate bearing 8, and the second central ring 56 are initially stationary between the position shown in Fig. 9 and the position shown in Fig. 2.

[0056] When the first central ring 32 abuts the second central ring 56, the two rings are aligned in a known manner. Thus, the male connection portion 2 also aligns with the female connection portion 4. In a first stage, shown in Figure 2, the alignment is achieved, but the first dog clutch head 16 is spaced from the second dog clutch head 28. In order to couple the two shafts, the two dog clutch heads must mesh.

[0057] In the second stage shown in FIG. 3, the first dog clutch head 16 and the second dog clutch head 28 are brought into contact with each other. In order for the second central ring 56 to move towards the second casing 10, this movement is prevented in the illustrated embodiment by the R-clips 64 arranged on the second guide rods 58. However, the R-clips 64 are elastic and when stress is applied to the second guide rods 58, the arms of the R-clips 64 move apart and the R-clip 64 slides over the narrowed portion of the second guide rods 58 to take up its position on the cylindrical body of the second guide rods 58.

[0058] The force that must be applied by the first central ring 32 to the second central ring 56 to displace it and the first central ring 32 towards the second casing 10 is based on the stiffness of the R-clip 64 and the shape of the second guide rod 58, in particular the diameter and the inclination of the narrowed portion. This force can be adapted to specifications during the design phase of the device. The resistance to the movement of the second central ring 56 can also be achieved by means other than those described in connection with the R-clip here, for example by hydraulic cylinders. By applying a predetermined minimum force to move the second central ring 56 together with the first central ring 32, the male connection part 2 and the female connection part 4 are aligned before the dog clutch heads abut and the shafts are correctly aligned.

[0059] When the first dog clutch head 16 abuts against the second dog clutch head 28, a force substantially corresponding to the force applied to the second central ring 56 to move the second central ring 56 is also applied to the movable assembly formed by the intermediate bearing 8 and the female connection part 4 and including the second dog clutch head 28. The movable assembly then enters the central hole of the second casing 10 while compressing the first spring 66. The first spring 66 is compressed in proportion to the applied axial force, and the movement of the movable assembly is limited when the flange 48 of the intermediate bearing 8 abuts against the second casing 10.

[0060] When the system moves from the second position shown in Figure 2 to the third position shown in Figure 3, it is highly unlikely that the teeth of the dog clutch members will directly mesh with each other exactly opposite to each other, and it is necessary to rotate the shaft so that the teeth of the dog clutch members mesh with each other. For example, when one end of the motor shaft is attached to the female connection part 4, that part is rotated. The rolling bearing 18' allows the female connection part 4 to rotate within the intermediate bearing 8 and drive the second dog clutch head 28. 4, the teeth 24' of the second dog clutch head 28 mesh with the teeth 24 of the first dog clutch head 16. Under the influence of the first spring 66, the movable assembly including the movable bearing 8 and the female connection part 4 is pressed against the male connection part 2, while the second spring 68 presses against the thrust washer 60 and exerts a stress on the second guide rod 58, so that the second center ring 56 remains in contact with the first center ring 32.

[0061] In the position shown in Figure 4, the motor shaft, attached at one end to the female connection part 4, drives the female connection part 4 which rotates in the intermediate bearing 8 and, via the dog clutch head, drives the male connection part 2 which is attached at one end of the rotated shaft. The tension provided by the first spring 66 maintains the connection between the dog clutch members.

[0062] 7 to 17 show application of the system to a hitch device, and more specifically, as a non-limiting example, to a hitch device for connecting agricultural implements to an agricultural tractor.

[0063] FIG. 7 shows an agricultural implement 100 having a trailer frame 102 and a drive shaft 104 having a universal joint 106 .

[0064] The agricultural implement 100 may be of any type and will not be described in detail here.

[0065] The towed frame 102 includes a lower cross member 108, an upper cross member 110, and a lower cross member 108. The cross member 110 has two upright members 112 connected thereto.

[0066] On one side of the universal joint 106 is a drive shaft 104 that is part of the agricultural implement and is provided by the manufacturer to drive the implement. On the other side of the universal joint 106 is a socket 114 suitable for engagement with a male connector 2.

[0067] FIG. 7 shows two support arms 116 supporting a part of the coupling device, more specifically the part of the coupling device comprising the first casing 6 and the male connection part 2. These support arms 116 have a free end in the form of a rod that engages with the U-shaped part 46. Each of these support arms 116 is mounted to pivot about a shaft 126 (see FIG. 20) that extends between the lower cross member 108 and the upper cross member 110. In each case, a resilient means, such as a gas spring 118 in the illustrated embodiment, applies a preload to the support arms 116 to hold them in a predetermined position (FIGS. 7, 16 and 18), where the end of the support arms 116 engages with the U-shaped part 46 to hold the part of the coupling device in a predetermined position. As will be explained further below in relation to FIG. 20, the support arms 116 can also be held in such a way that their free ends are held in a position spaced apart from the coupling device.

[0068] 8 is a schematic diagram of the rear of an agricultural tractor 200 equipped with a conventional three-point lifting mechanism including two cylindrical lower arms 204 and one upper arm 206, both of which are variable in length. The three-point lifting mechanism includes an inverted U-shaped towing frame 202 having a base 208 at an upper position and two legs 210 extending downwardly from the base 208. The upper arm (cylinder) 206 is connected substantially to the center of the base 208, and each lower arm 204 is connected to a corresponding leg 210 substantially near the free end of the leg 210.

[0069] The second casing 10 is attached to a support arranged on the tractor by means of two half clamps 72 , and the drive shaft, also called the power take-off, is received in the female connection 4 .

[0070] The towed frame 102 and the towing frame 202 can be connected together, for example by a mechanical joint structure. The upper base 208 of the towing frame 202 has the form of a beam with a substantially square cross section having two centering pins 214 on opposite sides of the legs 210. The upper cross member 110 of the towed frame 102 has the form of a beam with a cap 120 that projects towards the towing frame 202 to cover the base 208 of the towing frame 202. A cylindrical housing 122 corresponding to the centering pins 214 is provided in the cap 120 to receive the centering pins 214.

[0071] Similarly, as shown in FIG. 8, each of the legs 210 of the towing frame 202 has an end plate with two locking fingers 216 protruding therefrom. Correspondingly, the towed frame 102 has a corresponding locking hole 124 in the lower cross member 108. The two locking fingers 216 corresponding to the leg 210 are attached to a plate 226 extending substantially perpendicular to the corresponding leg 210 and protruding rearward relative to the leg 210. The plate 226 is slidably mounted to move away from or towards the end of the leg 210. A cylinder (not shown) provided in the leg 210 controls the movement of the plate 226 relative to the corresponding leg 210. The plate 226 is connected to the control cylinder by at least one rod 228, slides relative to the leg 210, is preloaded by a spring 230, and is located near the free end of the corresponding leg 210.

[0072] Figure 9 is a side view of the rear of an agricultural tractor comprising a towing frame 202 on which is mounted a support a portion of the coupling system shown in Figures 1 to 6. Figure 9 also shows a side view of the rear of an agricultural tractor comprising a portion of the coupling system shown in Figures 1 to 6, complementary to the portion mounted on the tractor, FIG. 1 is a schematic diagram of an agricultural implement having a towed frame 102.

[0073] In FIG. 9, the agricultural implement 100 is positioned to face the rear of the agricultural tractor 200 without touching it.

[0074] When the agricultural tractor 200 is in operation, the agricultural implement 100 remains in place and the agricultural tractor 200 backs up to approach the agricultural implement 200. During this operation, the tractor operator operates the hydraulic system of the agricultural tractor 200 to tilt the towing frame 202 by means of the variable length upper arm 206, so that the towing frame 202 is tilted at an angle of approximately 10 degrees relative to the towed frame 102. The operator also causes the base 208 of the towing frame 202, which includes the centering pin 214, to go under the cap 120 of the towed frame 102, so that the towing frame 202 is substantially centered relative to the towed frame 102. Since the agricultural implement 100 is free, the centering is automatically achieved by the cone-shaped centering pin 214.

[0075] FIG. 10 shows the towing frame 202 tilted relative to the towed frame 102 with the centering pins 214 beginning to insert into the corresponding cylindrical housings 122 of the towed frame 102 .

[0076] In this position, the two parts of the coupling device are close together and separated by a space of several tens of centimeters.

[0077] As shown in Fig. 10, the three-point lifting mechanism is lifted from a position where the agricultural implement 100 is placed on the ground. This causes the agricultural implement 100 to be lifted as shown in Fig. 11, but if the agricultural implement 100 is equipped with a suspension, the wheels of the agricultural implement 100 will remain on the ground and only the main body of the agricultural implement 100 will be lifted upward. During this operation, the towed frame 102 will be stationary relative to the towing frame 202, and the locking fingers 216 will face the locking holes 124 without being inserted into them.

[0078] In this position, the two frames are in an unlocked and coupled position and the power take-off is not driving the drive shaft 104 of the agricultural implement 100 .

[0079] As shown in the detailed view of Figure 11, the agricultural tractor 200 has a guide arrangement comprising a lateral guide plate having a circular upper edge 218 forming a guide surface. The guide arrangement may also comprise a second guide plate symmetrical to the first guide plate with respect to the second casing 10. The upper edge 218 engages with a finger 42 projecting from one side of the first casing 6, as will be described below. The guide arrangement also further comprises an arm 220 hinged to a transverse shaft 222. In Figure 11, the arm 220 is in a raised position with its end adjacent to the corresponding finger 42.

[0080] Above each lateral guide plate 234 there is a locking device. Figures 22 to 25 show an example of the locking device. As shown in Figures 22 to 24, each locking device has, for example, two jaws arranged substantially flush with the corresponding lateral guide plate 234 (substantially vertical and longitudinal plane substantially parallel to the longitudinal axis of the tractor). The lower jaw 236 is fixedly attached to the structure on the agricultural tractor 200 side, and the upper jaw 238 is hinged. A housing is formed between the lower and upper jaws. The upper jaw 238 opens and closes access to the housing by pivoting. A return spring 240 acts as a latch that applies a preload to the upper jaw 238, moving it to a closed position.

[0081] The arms 220 are operated using a locking cylinder 244, shown in Figure 25, to move each arm 220 to the lower position shown in Figure 12. The two arms 220 preferably have a common transverse axis 222, and a single locking cylinder 244 controls the movement of the arms 220. The locking cylinder 244 is preferably a double acting cylinder.

[0082] In a preferred embodiment, the lateral guide plate 234 and the lower jaw 236 are disposed directly on the support 74. As shown in Figures 16 and 17, the support 74 is generally U-shaped with a vertical base and two vertical side panels, each of which is cut to form a lateral guide plate 234 with an upper edge 218 on one side and a lower jaw 236 on the other side.

[0083] Here, the alignment of the two parts of the coupling device will be described. As shown in Figs. 11 and 12, a part of the coupling connected to the agricultural implement 100 is located higher than a part of the coupling connected to the agricultural tractor 200. As shown in Fig. 12, the arm 220 is then moved downward. Then, the cylinder constituting the upper arm 206 is operated to lower the towed frame 102 and the towing frame 202, so that the entire coupling device connected to the agricultural implement 100 is lowered. At this time, as shown in Fig. 13, the part of the coupling connected to the agricultural implement 100 is lowered, and the fingers 42 come to rest on the corresponding arms 220. Note that only a single arm 220 and a single finger 42 are shown.

[0084] Figure 22 substantially corresponds to the position shown in Figure 13. The two parts of the coupling device are opposed by a distance ranging from a few centimetres to a few tens of centimetres.

[0085] The assembly formed by the agricultural implement 100, the hitched frame 102 and the towing frame 202 is lowered by the cylinders constituting the upper arm 206, while the arm 220 is raised by the locking cylinder 244. In the final movement shown in Figs. 13 and 14, the arm 220 acts on the finger 42 to move the part of the coupling connected to the agricultural implement close to the part of the coupling connected to the tractor. The upper edge 218 of each lateral guide plate 234 guides the finger 42 in the final approach stage before the part of the coupling connected to the agricultural implement abuts against the coupling connected to the tractor. The upper edge 218 thus guides the corresponding finger 42 towards the bottom of the housing in the shape of a notch formed in the lateral guide plate 234. When the finger 42 reaches the corresponding notch, the arm 220 closes the notch and the finger is sealed at the bottom of the notch. The end point of the movement of the finger 42 is not determined by the bottom of the notch, but by the contact between the dog clutch members. The coupling device gradually moves to the position shown in FIG. 2, and the coupling device for the two shafts shown in FIGS. 1 to 6 moves sequentially to the positions shown in FIGS. 2 to 4 as described above. Usually, the drive shaft of the agricultural implement has a variable length. Therefore, when the arm 220 is actuated to cooperate with the finger 42, a part of the coupling device connected to the agricultural implement 100 moves toward the agricultural tractor 200. At this time, the end of the support arm 116 is guided by sliding in the U-shaped part 46 in which the support arm 116 is accommodated. Comparing FIG. 13 and FIG. 14, the difference in the relative position between the support arm 116 and the corresponding part 46 can be seen. At this time, the motor shaft of the agricultural tractor 200 is rotated to drive the female connection part to complete the connection of the two shafts.

[0086] The two parts of the coupling device can be joined together by means of a locking device. Each arm 220 (in theory one is sufficient) has a locking pin 242 which engages with a corresponding locking device. Thus, in parallel with the movements shown in Figures 2 to 4, each locking pin 242 is guided towards the jaw. The locking pin 242 engages with the corresponding upper jaw during the movement. Each jaw 236 is disposed on a corresponding arm 220 so as to be able to support the lower jaw 238 from below, which moves the jaw against a preload provided by a corresponding return spring 240. At the end of this movement, a locking pin 242 is located within a housing formed between the lower jaw 236 and the upper jaw 238. The upper jaw 238, under the action of the return spring 240, acts as a latch, controlling the closure of access to the housing when the locking pin 242 moves into position within the housing.

[0087] To complete the above-mentioned locking, an additional obstacle is formed between the coupling device attached to the tractor and the coupling device attached to the implement, for example a degree of freedom corresponding to rotation around an axis perpendicular to the plane of the drawing, such as a rotation around the finger 42, which corresponds to a lower degree of freedom. For this purpose, at least one anti-rotation pin 246 is provided on the coupling device on the implement side. The anti-rotation pin 246 can also be provided on the arm 220. In the embodiment shown for non-limiting and exemplary purposes, the anti-rotation pin 246 is arranged parallel to each finger 42 on each arm 38 of the support 34. Thus, two anti-rotation pins 246 are preferably provided on the support 34 arranged symmetrically with respect to the central plane. As shown in FIG. 24, the anti-rotation pin 246 abuts the corresponding arm 220 in the locking position of the locking device. In FIG. 24, the support 74, not shown in FIG. 23, is shown, but the return spring 240 is omitted in order to show the anti-rotation pin 246 in the locking position.

[0088] Once the shafts are coupled, the two frames are locked and the support arm 116 pivots and moves away from the coupling as shown in Figure 15 with the system in the connected and coupled position. Once the two shafts are coupled and engaged with each other, there is no need to support the shaft on the agricultural implement 100 and it is preferable to leave it free to allow free movement. The towed frame 102 and towing frame 202 are locked by engaging the locking fingers 216 with the corresponding locking holes 124. The respective cylinders 244 are actuated to actuate the corresponding plates 226 and insert the locking fingers 216 into the corresponding locking holes 124.

[0089] FIG. 20 shows a mechanism that allows the support arm 116 to rotate. As mentioned above, the support arm 116 is mounted to pivot about a shaft 126 that extends substantially vertically during normal use of the device. In the preferred embodiment shown, the support arm 116 comprises a plate secured to a perforated plate 128 that is integrally secured to the shaft 126, such as by welding. The perforated plate 128 extends in a plane that contains the pivot axis of the corresponding support arm 116, and comprises a number of mounting holes that allow the plate of the support arm 116 to assume various positions relative to the shaft 126. This feature allows the same towed frame to be adapted to a variety of agricultural implements. The gas spring 118 is connected to the perforated plate 128 at one end of the plate of the support arm 116.

[0090] The lower end of the perforated plate 128 is angled to form an inclined surface 130 relative to the remainder of the perforated plate 128. Figure 20 shows a roller 132 mounted below the inclined surface 130. The roller 132 is attached to the end of an arm 134 that projects through the lower cross member 108. The arm 134 is mounted parallel to the shaft 126. The roller 132 and inclined surface 130 are such that when the roller 132 is forced upwardly towards the perforated plate 128 or upper cross member 110, the perforated plate 128 pivots due to pressure applied by the gas spring 118 and the support arm 116 moves away from it.

[0091] The opening of the support arms 116 is preferably accomplished simultaneously with locking the towed frame 102 to the towing frame 202. To accomplish this, by way of non-limiting example, the plates 226 carrying the locking fingers 216 may each have a protrusion 232. As shown in Fig. 21, which is an enlarged detailed view of the bottom of the two assembled frames, the lugs 232 are located below the arms 134 supporting the rollers 132. Thus, when the plate 226 is actuated to lock the towed frame 102 to the towing frame 202 by inserting the locking fingers 216 into the locking holes 124, the lugs 232 act on the arms 134 acting on the ramp 130 via the rollers 132, opening the corresponding support arms 116. In the event of a hydraulic problem, the plate 226 is maintained by the springs 230 in a position corresponding to the locked frame, which is a safe position.

[0092] Figures 16 to 19 are supplementary views for better understanding of the structure of the mechanism described above. Figures 16 and 18 correspond to the position in which the support arm 116 is engaged with the U-shaped portion 46 shown in Figure 14, and Figures 17 and 19 correspond to the position in which the support arm 116 is open shown in Figure 15.

[0093] 16 and 17 are plan views. For example, the support 74 is fixed to a part of a coupling device connected to an agricultural tractor 200. In the embodiment shown, the support 74 has the form of a U-shaped member with a lateral vertical base on the tractor side for receiving the half clamp 72 and with two vertical side arms, partly integrated in the preferred embodiment shown, which extend towards the agricultural implement 202 and serve as a support for a guide device cooperating with, for example, the finger 42 and a locking device respectively comprising a lower jaw 236, an upper jaw 238 and a return spring 240.

[0094] In summary, coupling of an implement (in the illustrated example, an agricultural implement 100) to an apparatus (in the illustrated example, an agricultural tractor 200) is accomplished as follows.

[0095] First, the implement is fitted with a towed frame and the device is fitted with a towed frame, the towed frame being provided with means allowing it to be fixed to the towed frame.

[0096] Furthermore, the implement comprises a driven shaft that is driven by the device, which provides the energy or power that enables the implement to be operated.The implement comprises an engine having an output shaft called a power take-off.

[0097] The driven shaft of the tool comprises one portion of the coupling and the output shaft of the tool comprises a second portion of the coupling.

[0098] The portion of the coupling associated with the driven shaft of the tool includes one or more elements that are integrally attached to the driven shaft, e.g., by splines and / or pins, and that include a first dog clutch member that includes a tooth and groove arrangement, which is journalably mounted to the first casing.

[0099] Similarly, a portion of the coupling device associated with the output shaft of the machine is integrally mounted with the output shaft and comprises one or more elements provided with a teeth and groove arrangement or a second dog clutch member configured to engage with the first dog clutch member for being driven by the first dog clutch member. When the dog clutch members are properly engaged with each other, such a dog clutch system transmits substantially 100% of the power available from the output shaft to the driven shaft. Here, the element comprising the second dog clutch member is journalably mounted on an intermediate bearing mounted in a second casing fixed to the machine and can slide relative to the second casing substantially parallel to the output shaft.

[0100] The first casing and the intermediate bearing further comprise preferably conical centering means.

[0101] To couple an unpowered implement to a powered implement, an operator operates the implement to bring the implement closer to the implement. The towing frame is movably attached to the implement, and the operator brings the towing frame closer to the towed frame by adjusting its height from the ground and its inclination relative to the vertical. In the towed frame, a portion of the coupling device provided on the implement is held in a predetermined position by a holding and supporting device, so that the portion of the coupling device is positioned to substantially face another portion of the coupling device when the towed frame faces the towing frame at a position that is approximately coincident with the towed frame (e.g., about 0-20 cm).

[0102] The operator operates the towed frame to couple to the towing frame, bringing the two parts of the coupling device closer to each other. These parts are placed on the device and the implement, so that during this operation the cones of the first casing and the intermediate bearing abut against each other. In this way, these two coupling devices are automatically centered, with the first dog clutch member facing the second dog clutch member. To complete the centering of the cones to each other, for example, a matching system is used, which comprises at least one arm attached to one part of the device that engages with a finger attached to the other part of the device. The two dog clutch members are then aligned without abutting each other. When a sufficient force, predetermined based on the dimensions of the system, is applied between the two cones, the intermediate bearing moves towards the device by sliding against the second casing, and the teeth of the first dog clutch member abut against the teeth of the second dog clutch member. It is highly unlikely that the teeth of one dog clutch member will fit into the groove of the other dog clutch member, but it may do so. The output shaft of the device is rotated to engage the dog clutch members. A preload means urges the intermediate bearing towards the tool so that during rotation the two dog clutch members engage with each other. The shafts are coupled and the frames engage with each other. Preferably the retaining and supporting means of the part of the coupling device associated with the tool shifts to allow the first casing to move freely.

[0103] As described above, locking is performed automatically in parallel with this coupling operation, and after unlocking, decoupling is performed in the reverse order.

[0104] To achieve decoupling, it is sufficient to open the respective upper jaw 238. As for the arm 220, the two upper jaws 238 can be connected together by a connecting shaft 250 shown in Fig. 25. Also, a release cylinder 248 is provided for opening the upper jaws 238. By means of the connecting shaft 250, the release cylinder 248 controls the opening of the other upper jaw 238 as well.

[0105] The illustrated hitch arrangement allows an agricultural tractor operator to hook up an agricultural implement without leaving the cab of the tractor. Mechanical coupling and connection of the agricultural implement is easily and safely accomplished. No manual effort is required to connect the agricultural implement 100 and / or the agricultural tractor 200.

[0106] Similarly, agricultural implements connected to agricultural tractors can be detached without manual effort, thereby limiting the risk of injury.

[0107] The linkage system allows for perfect transfer of power from the tractor to the implement, and because the shafts are perfectly aligned there is no wear or unnecessary stress on the system.

[0108] Once connected, operation of the implement is unaffected in any way, just as if the implement were directly connected to the tractor's three-point hitch system.

[0109] The present invention is not limited to the preferred embodiments and variants described and illustrated herein, but relates to all variants of the embodiments within the scope of the claims of the present invention and within the reach of a person skilled in the art.

Claims

1. 1. A coupling device for coupling ends of two shafts, comprising a pair of dog clutch members, Each of the pair of dog clutch members is configured to be fixed to either end of the two shafts to be connected, the pair of dog clutch members comprises a first dog clutch member and a second dog clutch member having complementary shapes, the first dog clutch member is journaled within a first casing, the second dog clutch member is journaled within an intermediate bearing, the intermediate bearing is slidably mounted within a fixed second casing, the intermediate bearing is slidable relative to the second casing in a longitudinal direction that is parallel to the two shafts to be connected, and the intermediate bearing is elastically preloaded in the direction of the first casing. Coupling device.

2. 2. The coupling device of claim 1, wherein the first casing has a first conical surface facing the second casing and the second casing has a second conical surface facing the first casing, the first and second conical surfaces having complementary shapes to achieve alignment of the two shafts, and one of the first and second conical surfaces is a sliding conical surface mounted for sliding movement in the longitudinal direction relative to a casing corresponding to the one of the first and second casings, the sliding conical surface being elastically preloaded in the direction of the other conical surface.

3. 3. The coupling device of claim 2, wherein the sliding conical surface is capable of moving towards the corresponding casing against the preload in the direction of the other conical surface, and the sliding conical surface and the corresponding casing are provided with a delay means for initiating the movement of the sliding conical surface towards the corresponding casing only when a load equal to or greater than a predetermined minimum load in the longitudinal direction is applied to the sliding conical surface towards the corresponding casing.

4. 4. The coupling device of claim 3, wherein the delay means comprises at least one guide rod integral with the sliding conical surface, a hole inside the corresponding casing for at least partially receiving the guide rod, a slot extending transversely to the hole and intersecting the hole, and a resilient member having two arms, the guide rod having at least a cylindrical body and a region of reduced cross section slidable within the hole and having a smaller diameter than the cylindrical body, the resilient member being received within the slot, the region of reduced cross section being disposed between the two arms of the resilient member, and only when the load is applied to the sliding conical surface does the region of reduced cross section move towards a position on the cylindrical body so as to move away from one another.

5. 5. The coupling device according to claim 1, further comprising a connection means between the first casing and the second casing, the connection means comprising a protrusion on each side of one of the first casing and the second casing, the protrusion being integral with the one casing and protruding laterally outward from the one casing, and the other casing comprising a housing through which the protrusion enters and exits, a guide means for moving the protrusion toward the housing, a hook, and a lateral shaft extending laterally, the hook being configured to pivot about the lateral shaft between an open position that allows the protrusion to enter and exit the housing, and a closed position that prevents the protrusion from exiting the housing and holds the protrusion within the housing.

6. 6. A coupling device as claimed in claim 5, wherein said hooks are two in number, said two hooks being mounted to pivot about a common transverse axis, and movement of said hooks being controlled by a double acting hydraulic cylinder.

7. 7. The coupling device according to claim 6, wherein at least one of the two hooks is provided with a locking pin cooperating with a pair of jaws provided on the other casing and arranged such that the locking pin is located between the pair of jaws when the hook is in a closed position.

8. 8. The coupling device according to claim 7, wherein the pair of jaws comprises a fixed jaw and a movable jaw, and further comprises a return spring that applies a preload to the movable jaw toward the fixed jaw, and a cylinder that enables the movable jaw to move away from the fixed jaw against the return spring.

9. 1. A hitch device for connecting an implement to a lifting mechanism of a machine having a drive output shaft, comprising: The hitch device is a towing frame having mounting members allowing attachment to the lifting mechanism; a towed frame having attachment members allowing attachment to the implement; Equipped with The towing frame and the towed frame each have a joint surface, and the joint surface is configured to be integrally connectable to the towing frame of the towed frame; The hitch device is means for locking the towed frame relative to the towing frame in the integrally connected position; A coupling device according to any one of claims 1 to 8, Further equipped with The coupling device is mounted between the drive output shaft of the device and the driven shaft of the instrument. Hitch device.

10. 10. The hitch device of claim 9, wherein a first dog clutch member is connected to the driven shaft, and the towed frame has two arms capable of supporting the first casing, and is mounted to pivot between a closed position in which the free ends of the two arms support the first casing, and an open position in which the two arms are spaced apart and the free ends are spaced apart from the first casing.

11. 11. The hitch device of claim 9 or 10, wherein the towing frame has a structure including a cross member and two legs extending from the same side of the cross member, the towed frame has a structure including an upper cross member, a lower cross member and two upright members connecting an end of the lower cross member to an end of the upper cross member, the cross member of the towing frame has at least two centering pins, and the upper cross member of the towed frame has a cap extending toward the towing frame to cover the cross member of the towing frame and having at least two housings configured to receive the at least two centering pins.

12. 12. The hitch device of claim 11, wherein each of the two legs of the towing frame has at its free end a plate slidably attached to move away from or towards the end of the respective leg and having at least one locking finger disposed thereon, and the lower cross member of the towed frame has at least one locking hole disposed to receive the locking finger.

13. A hitch device as claimed in claim 12 which is dependent on claim 11 which is dependent on claim 10, comprising actuating means for actuating the two arms, said actuating means cooperating with said plate on which said at least one locking finger is arranged, and in a locking position of the towed frame to the towing frame, said arms are in said open position.

14. The hitch device according to any one of claims 9 to 12, wherein the first casing of the coupling device is attached to the towed frame side, and the second casing is attached to the towing frame side.

Images