A coupling device for two shafts and a hitch device equipped with the 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 specifically, it relates to the connection of a drive shaft and a driven shaft. The present invention also relates to a hitch device comprising a device for connecting two shafts.

[0002] As will be described in detail below, the technical problem of the device is to semi-automatically connect the driven shaft to the drive shaft when connecting a device provided with a receiving shaft, such as an agricultural implement, to a device such as an agricultural tractor provided with a drive shaft called a power take-off in the agricultural field. The semi-automatic connection allows an operator of the device to perform the connection work from the cab of the device while maintaining a distance from the connection means. [[BACKGROUND ART]]

[0003] French Patent Publication No. 2995756 and French Patent Publication No. 3018029 each relate to a hitch device for connecting an agricultural implement to a device such as an agricultural tractor. A towed frame is attached to said implement, and a towing frame is attached to said device.

[0004] These documents show means for semi-automatically connecting an implement to a device, wherein said connection is performed by an operator of the device without the operator of the device leaving the cab.

[0005] European Patent Application Publication No. 2098741 relates to a disconnection / cutting assembly for disconnecting a generator from a gearbox, comprising a first inner ball screw having angled threads on its outer surface, surrounding a rotating generator drive shaft, and rotating by engaging with the drive shaft. The inner ball screw is mounted on an undercut and interlocking toothed engagement member that engages with the teeth of the engagement member of the gearbox. An outer ball screw surrounds the inner ball screw and normally rotates together with it. A helical ball track is formed between the inner and outer ball screws. A brake is provided for slowing 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 makes it possible to disconnect the generator 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 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The object of the present invention is, in particular, to improve an existing system so as to simplify the existing system while ensuring semi-automatic connection from the device to the instrument and complete transmission of power under all circumstances. [Means for solving the problem]

[0008] This invention aims to solve the aforementioned problems.

[0009] The present invention is a connecting device for connecting the ends of two shafts, and a pair It is equipped with two dog clutch members. Each dog clutch member is configured to be fixable to the end of the connected shaft, and the two dog clutch members have complementary shapes.

[0010] According to the present invention, a first dog clutch member is pivotably mounted within a first casing. A second dog clutch member is pivotably mounted on 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 parallel to the two connected shafts. The intermediate bearing is elastically preloaded in the direction of the first casing.

[0011] This structure allows two shafts to be joined, each rotatably mounted within its own casing. Each shaft is associated with a dog clutch member. When these shafts are joined, they are aligned and pressed toward each other. It is virtually impossible for the dog clutch members to be positioned toward each other in 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, enabling translational engagement. This structure allows one dog clutch member to move axially relative to the other dog clutch member, and the elastic preload ensures proper engagement of these dog clutch members.

[0012] In this specification, the term "dog clutch member" means a mechanical coupling means having teeth and grooves that can achieve direct coupling with coupling means of the same type having complementary shapes.

[0013] To facilitate the 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 the alignment of the two shafts, the two conical surfaces have complementary shapes, and the first or second conical surface is mounted to slide longitudinally with respect to the casing on which the first or second conical surface is provided, and the sliding conical surface is elastically pre-pressed in the direction of the other conical surface.

[0014] In this embodiment, delay means are provided on the sliding conical surface and the corresponding casing to ensure proper alignment before these dog clutch members engage, and the movement of the conical surface is initiated only when a predetermined minimum longitudinal load is applied to the conical surface toward the casing. Here, the male and female conical surfaces, which are complementary shapes, are centering members that fit together to enable complete pre-positioning of the connecting members formed by the dog clutch members. This ensures that the connecting members are precisely positioned relative to each other and avoids mechanical failure. Preferably, a stage is provided in which the dog clutch members are fully aligned but not in contact with 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 narrow cross-sectional region slidable within a hole inside the corresponding casing, the corresponding casing extending laterally to the hole that at least partially receives the guide rod and having a slot intersecting the hole, an elastic member having two arms (an R-clip, in a non-limiting example) housed in the slot, and the narrow cross-sectional region positioned between the two arms of the elastic member (e.g., an R-clip).

[0016] Those skilled in the art will be able to immediately find other means for achieving the aforementioned delay function. This function can also be performed, for example, by one or more elastically preloaded latches. In these examples, this function is performed mechanically and automatically. It can also be controlled and executed by actuators such as hydraulics. This delay function is advantageous in that it ensures the pre-positioning of the connecting member (dog clutch member) and the realization of a clutch without the risk of damage.

[0017] In a preferred embodiment of such a coupling device, the coupling device further comprises connecting and locking means, wherein projections are provided on both sides of the dog clutch member, integral with the corresponding casing, and the other casing comprises a guide means for moving the projection toward the housing, and a hook provided to pivot about a transverse axis between an open position that allows the projection to move in and out of the housing and a closed position that prevents the projection from leaving the housing and holds the projection within the housing.

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

[0019] If the jaws are provided, for example, each of the pair of jaws consists of a fixed jaw and a movable jaw, a return spring provides preload to the movable jaw toward the fixed jaw, and a cylinder acts in the opposite direction to the return spring, allowing 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 an apparatus such as an agricultural tractor including a drive output shaft. The hitch device comprises a first frame which is a traction frame, the first frame including an attachment member enabling attachment to the lifting mechanism of the apparatus; a second frame which is a towed frame, the second frame including an attachment member enabling attachment to the implement; wherein the traction frame and the towed frame each have joint surfaces, the joint surfaces being configured to allow pairing of the towed frame with the traction frame, comprising means for relatively locking the towed frame with respect to the traction frame at the paired position. In particular, the hitch device further comprises a coupling device for coupling ends of the two shafts according to the present invention, the coupling device being mounted between the drive output shaft of the apparatus and the driven shaft of the implement.

[0021] In such a hitch device, the towed frame comprises, for example, two arms, the two arms being mounted to pivot between a closed position where free ends thereof hold a first casing of the coupling device and an open position where the arms are spaced apart and free ends thereof are spaced apart from the first casing.

[0022] In a preferred embodiment of the hitch device, the traction frame has a joint structure provided with a cross member having 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 ends of the lower cross member to ends of the upper cross member. The cross member of the traction frame has at least two centering pins, and the upper cross member of the towed frame has a key extending toward the traction frame and includes at least two housings each configured to receive a respective one of the centering pins.

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

[0024] In a preferred embodiment, the hitch device includes, for example, an actuator for operating the swivel-mounted arm, the actuator cooperating with the plate on which at least one locking finger is positioned to move the arm to an open position when the towed frame is locked to the towing frame.

[0025] In the hitch devices described herein, for example, the first casing of the coupling device is attached to the side of the towed frame, and the second casing is attached to the side of the towing frame. [Brief explanation of the drawing]

[0026] Other aspects, objects, and advantages of the present invention will be revealed by the following detailed description. The present invention will be better understood by reference to the accompanying drawings.

[0027] [Figure 1] Figure 1 is a perspective view of a device that connects two shafts. [Figure 2] Figure 2 is a longitudinal cross-sectional view of the coupling device at the first position. [Figure 3] Figure 3 is a longitudinal cross-sectional view of the coupling device at the second position. [Figure 4] Figure 4 is a longitudinal cross-sectional view of the coupling device at the third position. [Figure 5] Figure 5 is a detailed cross-sectional view at the first location shown in Figure 2. [Figure 6] Figure 6 is another detailed cross-sectional view at the first location shown in Figure 2. [Figure 7]Figure 7 is a schematic diagram showing an agricultural device comprising a towed frame and a part of the coupling device shown in Figure 1. [Figure 8] Figure 8 is a schematic diagram showing the rear of an agricultural tractor, which includes a towing frame and a part of the coupling device shown in Figure 1. [Figure 9] Figure 9 is a rear side view of the agricultural tractor shown in Figure 8, facing the agricultural equipment shown in Figure 7 before connection. [Figure 10] Figure 10 shows the first step in connecting the device shown in Figure 7 to the rear of the tractor shown in Figure 8. [Figure 11] Figure 11 shows the second stage of connecting the device shown in Figure 7 to the rear of the tractor shown in Figure 8, along with a detailed view of part of the coupling device. [Figure 12] Figure 12 shows the third stage of connecting the device shown in Figure 7 to the rear of the tractor shown in Figure 8, along with a detailed view of part of the coupling device. [Figure 13] Figure 13 shows the fourth stage, in which the device shown in Figure 7 is connected to the rear of the tractor shown in Figure 8, along with a detailed view of part of the coupling device. [Figure 14] Figure 14 shows the fifth stage, in which the device shown in Figure 7 is connected to the rear of the tractor shown in Figure 8, along with a detailed view of part of the coupling device. [Figure 15] Figure 15 shows the device shown in Figure 7, located at the rear of the tractor shown in Figure 8, along with a detailed view of part of the coupling device. [Figure 16] Figure 16 is a top view corresponding to Figure 14. [Figure 17] Figure 17 is a top view corresponding to Figure 15. [Figure 18] Figure 18 is an elevation view of the frame on the fixture side, corresponding to Figure 14. [Figure 19] Figure 19 is an elevation view of the tractioned frame shown in Figure 18, at the position corresponding to Figure 15. [Figure 20] Figure 20 is a detailed, enlarged perspective view of the tractioned frame. [Figure 21]Figure 21 is a magnified detail view of the two assembled frames seen from below. [Figure 22] Figure 22 is a side view of the coupling device shown in Figure 1, which includes a locking device in the open position and is attached to a support. [Figure 23] Figure 23 is a diagram similar to Figure 22, showing the locking device in the closed position with the support omitted. [Figure 24] Figure 24 is a diagram similar to Figure 23, showing the locking device with a support body but without the spring. [Figure 25] Figure 25 is a rear view of the coupling device shown in Figures 22 to 24. [Modes for carrying out the invention]

[0028] The attached drawings and the following description contain elements that are largely self-evident. Therefore, they are intended not only to provide a better understanding of the disclosures of the present invention, but also to clarify definitions where appropriate.

[0029] Figure 1 shows a device for connecting two shafts. Here, the two shafts to be connected are spline shafts, each having a male end and a female end. The device shown in Figure 1 comprises a male connector 2 that receives the female end of the shaft and a female connector 4 that engages with the male end of the shaft. Those skilled in the art will understand from the following description that this connecting device can also connect two shafts, each having a male end, or two shafts, each having a female end.

[0030] The male connector 2 is mounted within the first casing 6 by a rolling bearing, and the female connector 4 is mounted within an intermediate bearing 8, which is slidably mounted within a second casing 10 separate from the first casing 6, by a rolling bearing. This structure is clearly shown in Figures 2, 3, and 4, which show longitudinal cross-sectional views of the device shown in Figure 1.

[0031] In the following description, the longitudinal direction refers to the direction defined by the connected shafts, the male connector 2, and the female connector 4.

[0032] The male connector 2 has a connector 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 a non-limiting illustrated embodiment, the connecting end 12 is in the form of a spline shaft. The connecting end 12 extends from a solid cylindrical body 14. The solid cylindrical body 14 comprises a pair of rolling bearings 18, the outer surface of which is machined to receive the rolling bearings 18. The outer surface of the solid cylindrical body 14, which is not described in detail, comprises a stopper for the rolling bearings, a machined surface that serves as a seating surface for the rolling bearings 18, a threaded portion that receives a nut 20, and an area that cooperates with the seal 22 to protect the rolling bearings 18.

[0034] The first dog clutch head 16 is constructed as a single component with a solid cylindrical body 14 and a connecting end 12. In the illustrated example, this single component is obtained by machining. The end of the first dog clutch head 16 is located on the side opposite to 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 cross-section, and teeth 24 protruding from the cross-section are regularly arranged on the outer circumference of the cross-section.

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

[0036] The cylindrical body 26 has a housing 30 suitable for receiving the ends of the connected shafts. Therefore, the shape of the housing 30 needs to match the shape of the shafts. In the illustrated embodiment, the housing 30 is configured to receive a spline shaft (not shown). The outer surface of the cylindrical body 26 is machined to receive a pair of rolling bearings 18'. The outer surface, which is not described in detail, includes stoppers for the rolling bearings, a machined surface that serves as a seat for the rolling bearings 18', a threaded portion for receiving a nut 20', and an area that cooperates with a 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 is the same as the diameter of the first dog clutch head 16. The second dog clutch head 28 also has a cross-section. Teeth 24' protrude from this cross-section. Teeth 24' mesh with the teeth 24 of the first dog clutch head 16.

[0038] The first casing 6 is a cylindrical component whose inner surface is machined to receive the outer ring of the rolling bearing 18. The housing formed within the first casing 6 to receive the rolling bearing 18 has one end closed by the seal 22. On the side opposite 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 includes a first central ring 32, which is a separate component from the first casing 6 in the illustrated embodiment. The first central ring 32 is screwed into a flange provided on the first casing 6 for assembly purposes near the first dog clutch head 16. The first central ring 32 has a frustoconical outer surface that is coaxial with the first casing 6 and the male connector 2.

[0040] On the side opposite to the first dog clutch head 16, the first casing 6 is provided with means for attaching to a support 34. The support 34 consists of a plurality of parts. In the illustrated embodiment, the support 34 consists of a stirrup-shaped part having a base 36 and two arms 38. The base 36 extends laterally relative to the male connector 2 and has the function of attaching the support 34 to the first casing 6. A flange 40 attached to the first casing 6 is used 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 has fingers 42 that extend outward from the arm 38 toward the outside of the stirrup, i.e., away from the first casing 6. The two fingers 42 are coaxial with the arms 38 and extend laterally relative to the male connector 2. Each arm 38 is provided with a lateral mounting portion 44 that extends outward in the longitudinal direction and away from the first casing 6. These lateral mounting portions 44 are adapted to a device to which the support 34 and the corresponding male connector 2 are attached. In the illustrated non-limiting and exemplary embodiment, each of the lateral mounting portions 44 has a mounting plate to which a U-shaped portion 46 is fixed to its outer surface. The free end of the arm of the U-shaped portion 46 is flared, and the U-shaped portion 46 is oriented longitudinally.

[0041] As described above, the female connector 4 is located within the intermediate bearing 8. The intermediate bearing 8 is mounted within the fixed second casing 10 so as to be able to move longitudinally.

[0042] The intermediate bearing 8 is a cylindrical component, and its inner surface is machined to receive the outer ring of the rolling bearing 18' to which the female connector 4 is attached. The housing 30 formed inside the intermediate bearing 8 to receive the rolling bearing 18' is closed at one end by a seal 22'. On the side opposite the seal 22', which is the second dog clutch head 28 side, 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 the seal 22'. The flange 48 also comprises a longitudinal hole for allowing the flange 48 to be guided relative to the second casing 10, and a longitudinal hole for the movement of a guide rod, which will be described below in relation to Figures 5 and 6.

[0044] This specification assumes that the second casing 10 is fixed, and therefore serves as the basis for the relative operation of the various components described below. The second casing 10 has a substantially parallelepiped shape through which a longitudinal central hole passes, allowing the movable assembly formed by the female connector 4 and the intermediate bearing 8 to slide. Longitudinal blind holes and longitudinal transverse holes are arranged around the central hole. In the illustrated embodiment, there are four blind holes and four through holes. All four blind holes are formed longitudinally and open to the same face (back) of the second casing 10, and longitudinal threads are provided at the bottom of the blind holes.

[0045] As described above, the female connector 4 and the intermediate bearing 8 constitute a movable assembly relative to the second casing 10. Guidance is provided by the central hole in the second casing 10. In the illustrated non-limiting embodiment, a cushion 50 is positioned between the two wiper seals 52 and provided between the outer surface of the intermediate bearing 8 and the inner surface of the central hole in the second casing 10.

[0046] Four first guide rods 54 are provided to guide the movable assembly, and in particular to prevent rotation of the movable assembly relative to the second casing 10. Referring to Figure 5, an enlarged cross-sectional view of the coupling device in the first position in Figure 2, the first guide rods 54 are arranged longitudinally. The first guide rods 54 have a threaded form 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 functions as a stopper for the flange 48, as shown in Figure 5. The flange 48 is located between the head of the first guide rod 54 and the back surface of the second casing 10 (the surface where the blind hole opens), and the maximum travel of the movable assembly is defined by the distance between the head of each first guide rod 54 and the back surface of the second casing 10, but is shorter than that distance by the thickness of the flange 48.

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

[0048] As shown in Figure 6, the second central ring 56 includes a second guide rod 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, and this engagement fixes the second guide rod 58 to the second central ring 56. The shoulders of the second guide rods 58 cooperate with the shoulders formed in the corresponding threaded holes to ensure the correct relative positioning of the second guide rods 58 with respect to the second central ring 56.

[0050] Each second guide rod 58 has a cylindrical body that passes through a hole in the intermediate bearing 8, crosses the flange 48 of the intermediate bearing 8, and enters a hole that penetrates the second casing 10. From the cylindrical body, a smaller diameter region extends further, followed by a shoulder, after which the end of the second guide rod 58 returns to a diameter matching that of its cylindrical body. The end of the second guide rod 58 is provided with a central threaded hole for receiving a screw to hold a thrust washer 60 in place.

[0051] As shown in Figures 2 and 6, the second casing 10 may have a slot 62 in a region of the second guide rod 58 where the diameter is reduced. 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 having two elastic arms that are preloaded toward each other. One arm is substantially straight, and the other arm has a concave region between two protruding regions relative to the first arm. Such an R-clip is provided such that the first arm is housed in a through-hole of a pin and the concave region contacts the outer portion 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, and the second guide rod is positioned between the two protruding regions of the clip.

[0052] Figure 6 is a diagram including springs. The first spring 66 is a coil spring and is positioned 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 positioned between the flange 48 of the movable intermediate bearing 8 and the fixed second casing 10. The first spring 66 tends to move the flange 48 of the intermediate bearing 8 away from the back of the second casing 10. That is, this allows the intermediate bearing 8 and the female connector 4 to exit through the central hole of the second casing 10. The second spring 68 is housed within the hole of the second casing 10. Each of the second springs 68 is mounted between the stopper 70 and the thrust washer 60 attached to the end of the second guide rod 58. The second spring 68 causes the second guide rod 58 to tend to come out of the hole in the second casing, which allows the second central ring 56 to move away from the second casing 10.

[0053] The second casing 10 has two lateral grooves formed on two opposing surfaces, as shown in the figure, each groove receiving a half clamp 72 for attachment to the support 74 shown in Figures 5, 6, 16, and 17.

[0054] The operation of the device that connects the two shafts will be explained using Figures 2 to 4.

[0055] As shown in Figure 9, the male connector 2 is moved closer to the female connector 4 from a position where the male connector 2 is separated from the female connector 4. The second casing 10 is fixed, and initially, the movable assembly with the female connector 4 and intermediate bearing 8 and the second central ring 56 are stationary between the position in Figure 9 and the position in Figure 2.

[0056] When the first central ring 32 contacts the second central ring 56, the alignment of these two rings is performed by a known method. Therefore, the male connector 2 also aligns with the female connector 4. In the first stage shown in Figure 2, alignment is performed, but the first dog clutch head 16 is separated from the second dog clutch head 28. In order to connect the two shafts, the two dog clutch heads need to mesh.

[0057] In the second stage shown in Figure 3, the first dog clutch head 16 and the second dog clutch head 28 are brought into contact. The first dog clutch head 16 is brought closer to the second dog clutch head 28. For this to happen, the second central ring 56 must approach the second casing 10. In the illustrated embodiment, this movement is prevented by an R-clip 64 positioned on the second guide rod 58. However, the R-clip 64 is elastic, and when stress is applied to the second guide rod 58, the arms of the R-clip 64 move away from it, and the R-clip 64 slides on the narrow part of the second guide rod 58 so that it takes position on the cylindrical body of the second guide rod 58.

[0058] The force to be applied from the first central ring 32 to the second central ring 56 in order to displace the second central ring 56 and the first central ring 32 toward the second casing 10 is based on the rigidity of the R clip 64 and the shape of the second guide rod 58, particularly the diameter and inclination of the constricted section. This force can be adapted to the specifications during the design phase of the device. Resistance to the movement of the second central ring 56 can also be achieved by means other than those described herein in relation to the R clip, such as a hydraulic cylinder. By applying a predetermined minimum force to move the second central ring 56 together with the first central ring 32, the male connector 2 and the female connector 4 align before the dog clutch heads make contact, and the shafts are properly aligned.

[0059] When the first dog clutch head 16 is brought into contact with 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 connector 4, which includes the second dog clutch head 28. The movable assembly then enters the central hole of the second casing 10, 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 restricted when the flange 48 of the intermediate bearing 8 comes into contact with 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, there is virtually no possibility that the teeth of the dog clutch members will directly mesh with each other in an exact manner; therefore, the shaft must be rotated so that the teeth of the dog clutch members mesh with each other. For example, if one end of the motor shaft is attached to the female connector 4, that part will rotate. The rolling bearing 18' causes the female connector 4 to rotate within the intermediate bearing 8, driving the second dog clutch head 28. The teeth 24' of the second dog clutch head 28 mesh with the teeth 24 of the first dog clutch head 16, as shown in Figure 4. Due to the influence of the first spring 66, the movable assembly including the movable bearing 8 and the female connector 4 is pushed against the male connector 2, and at the same time, the second spring 68 pushes the thrust washer 60, applying stress to the second guide rod 58, so that the second central ring 56 remains in contact with the first central ring 32.

[0061] In the position shown in Figure 4, the motor shaft, with one end attached to the female connector 4, drives the female connector 4, which rotates within the intermediate bearing 8, and drives the male connector 2, which is attached to the other end of the rotating shaft, via the dog clutch head. The connection between the dog clutch members is maintained by the stress from the first spring 66.

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

[0063] Figure 7 shows an agricultural tool 100 equipped with a towed frame 102 and a drive shaft 104 equipped with a universal joint 106.

[0064] Agricultural equipment 100 can be of any type, so it will not be described in detail here.

[0065] The towed frame 102 consists of a lower horizontal member 108 and an upper horizontal member 110, with the lower horizontal member 108 above It comprises two upright members 112 connected to a horizontal member 110.

[0066] One side of the universal joint 106 has a drive shaft 104, which is part of an agricultural tool and is provided by the manufacturer to drive the tool. The other side of the universal joint 106 has a socket 114 suitable for engagement with the male connector 2.

[0067] Figure 7 shows two support arms 116 that support a portion of the coupling device, more specifically, a portion of the coupling device comprising a first casing 6 and a male connector 2. These support arms 116 have free ends in the form of rods that engage with a U-shaped section 46. Each of these support arms 116 is mounted to pivot around a shaft 126 (see Figure 20) extending between a lower crossbar 108 and an upper crossbar 110. In either case, an elastic means, such as a gas spring 118 in the illustrated embodiment, preloads the support arms 116 to hold them in place (Figures 7, 16, and 18), where the ends of the support arms 116 engage with the U-shaped section 46 to hold the portion of the coupling device in place. As will be further described below in relation to Figure 20, the support arms 116 can also be positioned such that their free ends are held away from the coupling device.

[0068] Figure 8 schematically shows the rear of an agricultural tractor 200 equipped with a conventional three-point lifting mechanism, which includes two cylindrical lower arms 204 and one upper arm 206, both of variable 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 downward 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 the corresponding leg 210 near its substantially free end.

[0069] The second casing 10 is attached to a support positioned on the tractor by two half clamps 72, and the drive shaft, also called the power takeoff, is housed in the female connector 4.

[0070] The towed frame 102 and the towing frame 202 are connected integrally to each other, for example, by a mechanical joint structure. The upper base 208 of the towing frame 202 has the form of a substantially square cross-section beam with two centering pins 214 on the opposite side of the leg portion 210. The upper cross member 110 of the towed frame 102 has the form of a beam with a cap 120 that projects toward the towing frame 202 so as to cover the base 208 of the towing frame 202. A cylindrical housing 122 corresponding to the centering pins 214 is provided within the cap 120 to receive the centering pins 214.

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

[0072] Figure 9 is a rear side view of an agricultural tractor equipped with a towing frame 202 to which a part of the coupling system shown in Figures 1 to 6 is attached to a support. Figure 9 also shows a part of the coupling system shown in Figures 1 to 6 that is complementary to the part attached to the tractor, This diagram schematically shows an agricultural device equipped with a towed frame 102.

[0073] In Figure 9, the agricultural tool 100 is positioned so as to face the rear of the agricultural tractor 200 without touching the rear of the agricultural tractor 200.

[0074] When the agricultural tractor 200 is in operation, the agricultural equipment 100 remains in place, and the agricultural tractor 200 reverses and approaches the agricultural equipment 200. During this operation, the tractor operator operates the hydraulic system of the agricultural tractor 200 to tilt the towing frame 202 using 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. Also, the operator's operation causes the base 208 of the towing frame 202, equipped with a centering pin 214, to fit under the cap 120 of the towed frame 102, so that the towing frame 202 is positioned substantially centered relative to the towed frame 102. Since the agricultural equipment 100 is in a free state, it is automatically centered by the conical centering pin 214.

[0075] Figure 10 shows the towing frame 202 tilted relative to the towed frame 102, with the centering pin 214 beginning to be inserted into the cylindrical housing 122 of the corresponding towed frame 102.

[0076] At 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 Figure 10, the three-point lifting mechanism lifts the agricultural equipment 100 from its position on the ground. As a result, the agricultural equipment 100 is lifted as shown in Figure 11. However, if the agricultural equipment 100 is equipped with a suspension, the wheels of the agricultural equipment 100 remain on the ground, and only the body of the agricultural equipment 100 is lifted upward. During this operation, the towed frame 102 remains stationary relative to the towing frame 202, and the locking fingers 216 face the locking holes 124 without being inserted into them.

[0078] In this position, the two frames are in the unlocked and linked position, and the power takeoff is not driving the drive shaft 104 of the agricultural equipment 100.

[0079] As shown in the detailed view of Figure 11, the agricultural tractor 200 has a guide device comprising a lateral guide plate having a circular upper edge 218 that forms a guide surface. The guide device may also include 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 protruding from one side of the first casing 6, as will be described later. The guide device also further comprises an arm 220 hinged to the lateral shaft 222. In Figure 11, the arm 220 is in the raised position, and its end is close to the corresponding finger 42.

[0080] A locking device is located above each lateral guide plate 234. Figures 22 to 25 illustrate the locking devices. As shown in Figures 22 to 24, each locking device has, for example, two jaws positioned substantially coplanar with the corresponding lateral guide plate 234 (a substantially vertical and longitudinal plane substantially parallel to the longitudinal axis of the tractor). The lower jaw 236 is attached and fixed to the structure on the agricultural tractor 200 side, and the upper jaw 238 is attached by a hinge. 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, preloading the upper jaw 238 and moving it to the closed position.

[0081] To move each arm 220 to the lower position shown in Figure 12, the arms 220 are operated using the locking cylinder 244 shown in Figure 25. The two arms 220 preferably have a common horizontal 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 positioned directly on the support 74. As shown in Figures 16 and 17, the support 74 is substantially U-shaped and has a vertical base and two vertical side plates. Each side plate 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 explained. As shown in Figures 11 and 12, a portion of the coupling connected to the agricultural equipment 100 is positioned higher than a portion of the coupling connected to the agricultural tractor 200. As shown in Figure 12, the arm 220 is then moved downward. Subsequently, by operating the cylinders that make up the upper arm 206, the towed frame 102 and the towing frame 202 are lowered, causing the entire coupling device connected to the agricultural equipment 100 to descend. At this time, as shown in Figure 13, a portion of the coupling connected to the agricultural equipment 100 descends, and the fingers 42 come to rest on their respective corresponding arms 220. Note that only a single arm 220 and a single finger 42 are illustrated.

[0084] Figure 22 substantially corresponds to the position shown in Figure 13. The two parts of the coupling device are facing each other within a range of a few centimeters to several tens of centimeters.

[0085] The assembly formed by the agricultural equipment 100, the towed frame 102, and the towing frame 202 is lowered by the cylinder constituting the upper arm 206, while the arm 220 is raised by the locking cylinder 244. In the final operation shown in Figures 13 and 14, the arm 220 acts on the fingers 42 to move a portion of the coupling device attached to the agricultural equipment so that it approaches a portion of the coupling device attached to the tractor. The upper edges 218 of each lateral guide plate 234 guide the fingers 42 in the final approach phase before the portion of the coupling device attached to the agricultural equipment contacts the coupling portion attached to the tractor. Thus, the upper edges 218 guide the corresponding fingers 42 toward the bottom of the housing which has the shape of a notch formed in the lateral guide plate 234. When the fingers 42 reach the corresponding notch, the arm 220 closes the notch, and the fingers are sealed to the bottom of the notch. The end point of the finger 42's movement is determined not 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 Figure 2, and the coupling devices for the two shafts shown in Figures 1 to 6 move sequentially to the positions shown in Figures 2 to 4 as described above. Typically, the drive shaft of an agricultural tool is of variable length. Therefore, when the arm 220 is actuated and cooperates with the finger 42, a portion of the coupling device connected to the agricultural tool 100 moves toward the agricultural tractor 200. In this process, the end of the support arm 116 is guided by sliding within the U-shaped section 46 in which the support arm 116 is housed. Comparing Figures 13 and 14, the difference in the relative position of the support arm 116 and the corresponding section 46 can be seen. At this time, the motor shaft of the agricultural tractor 200 is rotated to drive the female connector and complete the coupling of the two shafts.

[0086] By using a locking device, the two parts of the coupling device can be joined. Each arm 220 (theoretically one is sufficient) has a locking pin 242 that engages with the corresponding locking device. Thus, in parallel with the operation shown in Figures 2 to 4, each locking pin 242 is guided toward the jaw. The locking pin 242 moves toward the corresponding jaw during movement. The lower jaws 238 are positioned on their respective arms 220 so as to support them from below, and move against a preload applied by the corresponding return springs 240. At the end of this movement, the locking pin 242 is located within a housing formed between the lower jaws 236 and the upper jaws 238. The upper jaws 238 act as a latch through the action of the return springs 240, and when the locking pin 242 moves into a predetermined position within the housing, it controls the closing of access to the housing.

[0087] To complete the lock described above, an additional obstacle is formed between the coupling device attached to the tractor and the coupling device attached to the equipment to reduce the degree of freedom corresponding to rotations around an axis perpendicular to the plane of the drawing, such as rotation around the finger 42. For this purpose, the coupling device on the equipment side is provided with at least one anti-rotation pin 246. The anti-rotation pin 246 may also be provided on the arm 220. In embodiments illustrated for non-limiting and illustrative purposes, the anti-rotation pin 246 is positioned parallel to each finger 42 on each arm 38 of the support 34. Therefore, it is preferable that two anti-rotation pins 246 are provided on the support 34 which is symmetrically arranged with respect to the central plane. As shown in Figure 24, the anti-rotation pin 246 abuts against the corresponding arm 220 in the locked position of the locking device. In Figure 24, a support 74 not shown in Figure 23 is shown, but the return spring 240 is omitted in order to illustrate the anti-rotation pin 246 in the locked position.

[0088] Once the shafts are connected, the two frames are locked, and the support arm 116 pivots and moves away from the coupling device, as shown in Figure 15, when the system is connected and coupled. Once the two shafts are connected and engaged with each other, it is no longer necessary to support the shaft on the agricultural equipment 100 side, so it is preferable to leave the shaft free to allow for free movement. The towed frame 102 and the towing frame 202 are locked by engaging the locking fingers 216 with the corresponding locking holes 124. The actuation of the respective cylinders 244 acts on the corresponding plates 226, and the locking fingers 216 are inserted into the corresponding locking holes 124.

[0089] Figure 20 shows a mechanism that allows the support arm 116 to rotate. As described above, the support arm 116 is mounted to pivot around a shaft 126 that extends substantially vertically when the device is normally in use. In the illustrated preferred embodiment, the support arm 116 has a plate fixed to a perforated plate 128 which is fixed to the shaft 126 by welding or other means to be integral with it. The perforated plate 128 extends in a plane that includes the pivot axis of the corresponding support arm 116 and has numerous mounting holes that allow the plate of the support arm 116 to take on various positions relative to the shaft 126. This feature makes it possible to apply the same towed frame to various agricultural tools. A 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 inclined, forming an inclined surface 130 relative to the rest of the perforated plate 128. Figure 20 shows a roller 132 located below the inclined surface 130. The roller 132 is attached to the end of an arm 134 that protrudes through the lower cross member 108. The arm 134 is mounted parallel to the shaft 126. When the roller 132 is pressed upward toward the perforated plate 128 or the upper cross member 110, the pressure applied by the gas spring 118 causes the perforated plate 128 to pivot, moving the support arm 116 away from it.

[0091] The operation to open the support arm 116 is preferably performed simultaneously with locking the towed frame 102 to the towing frame 202. To achieve this, in a non-limiting example, each plate 226 equipped with locking fingers 216 may have projections 232. As shown in Figure 21, an enlarged detail view showing the bottom of the two assembled frames, the projection 232 is positioned below the arm 134 that supports the roller 132. Thus, when the plate 226 is actuated and the locking finger 216 is inserted into the locking hole 124, thereby locking the towed frame 102 to the towing frame 202, the projection 232 acts on the arm 134 acting on the inclined surface 130 via the roller 132, opening the corresponding support arm 116. In the event of a hydraulic problem, the plate 226 is held in place by the spring 230 in a safe position, corresponding to the locked state of the frame.

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

[0093] Figures 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 illustrated embodiment, the support 74 has the form of a U-shaped member. The U-shaped member has a lateral vertical base on the tractor side that receives a half clamp 72 and extends toward the agricultural tool 202, and functions as a support for a guide device that cooperates with a locking device comprising, for example, a finger 42 and a lower jaw 236, an upper jaw 238, and a return spring 240, respectively, and in the illustrated preferred embodiment, comprises two vertical side arms that are partially integrated.

[0094] In short, the connection of the equipment (agricultural equipment 100 in the illustrated example) to the device (agricultural tractor 200 in the illustrated example) is achieved as follows:

[0095] First, a traction frame is attached to the device, and a traction frame is attached to the apparatus. The traction frame is equipped with means to enable fixation to the traction frame.

[0096] Furthermore, the device includes a driven shaft that is driven by the apparatus, thereby supplying the energy or power that enables the device to operate. The apparatus also includes an engine with an output shaft called a power takeoff.

[0097] The driven shaft of the device includes a part of the coupling device, and the output shaft of the device includes a second part of the coupling device.

[0098] A portion of the coupling device associated with the driven shaft of the instrument includes one or more elements that are integrally mounted with the driven shaft, for example by splines and / or pins, and include a first dog clutch member having teeth and grooves. The elements are pivotably mounted to the first casing.

[0099] Similarly, a portion of the coupling device associated with the output shaft of the apparatus is mounted integrally with the output shaft and comprises one or more elements having teeth and groove mechanisms, 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 approximately 100% of the power obtained from the output shaft to the driven shaft. Here, the element comprising the second dog clutch member is pivotably mounted on an intermediate bearing attached to a second casing fixed to the apparatus, and is capable of sliding against the second casing substantially parallel to the output shaft.

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

[0101] To connect a non-powered device to a powered device, the operator operates the device to bring it close to the device. The towing frame is movably attached to the device, and the operator adjusts the height from the ground and the inclination relative to the vertical to bring the towing frame closer to the towed frame. On the towed frame, a portion of the coupling device provided on the device is held in place by a holding and support device, so that portion of the coupling device is positioned substantially opposite the other portion of the coupling device when the towed frame is facing the towing frame at a position where they are approximately aligned (e.g., about 0-20 cm).

[0102] The operator manipulates the towed frame to connect it to the towing frame, bringing the two parts of the coupling device closer together. As these parts are positioned in the device and equipment, the conical portions of the first casing and the intermediate bearing come into contact with each other during this operation. In this way, the two coupling devices are automatically centered, and the first dog clutch member faces the second dog clutch member. To complete the centering of the cones toward each other, a matching system is used, for example, which includes at least one arm attached to a part of the device that engages with fingers attached to other parts of the device. The two dog clutch members are then aligned without coming into contact with each other. When a sufficient force, predetermined based on the dimensions of the system, is applied between the two cones, the intermediate bearing moves toward the device by sliding against the second casing, and the teeth of the first dog clutch member come into contact with the teeth of the second dog clutch member. It is unlikely, but possible, that the teeth of one dog clutch member will fit into the groove of the other dog clutch member. The output shaft of the device is rotated to engage the dog clutch members. The intermediate bearing is pressed toward the device by a preloading means so that the two dog clutch members engage with each other during rotation. The shafts are connected and the frames engage with each other. Preferably, some of the holding and supporting means of the coupling device associated with the device are shifted so that the first casing can move freely.

[0103] As mentioned above, locking is performed automatically in parallel with this linking operation. After unlocking, the linking is unlinked in the reverse order.

[0104] To disconnect the units, it is sufficient to open each upper jaw 238. Regarding the arm 220, the two upper jaws 238 can be connected together by the coupling shaft 250 shown in Figure 25. A release cylinder 248 is also provided for opening the upper jaws 238. The coupling shaft 250 controls the release cylinder 248 to open the other upper jaw 238 as well.

[0105] The illustrated hitch device allows the operator of an agricultural tractor to connect agricultural equipment without leaving the tractor's cab. Mechanical coupling and connection of agricultural equipment is performed easily and safely. No manual work is required for connecting agricultural equipment 100 and / or agricultural tractor 200.

[0106] Similarly, agricultural equipment attached to agricultural tractors can be removed without manual operation, thus limiting the risk of injury.

[0107] The coupling system enables complete power transmission from the tractor to the equipment. Because the shafts are perfectly aligned, the system does not experience wear or unnecessary stress.

[0108] Once connected, the operation of the device will not be affected in any way, just as if it were directly connected to the tractor's three-point coupling system.

[0109] The present invention is not limited to the preferred embodiments and variations described and illustrated herein. The present invention also relates to variations of all embodiments within the scope attainable by those skilled in the art within the scope of the claims of the present invention.

Claims

1. A hitch device for connecting an instrument having a driven shaft to a lifting mechanism of a device having a drive output shaft, The hitch device is A towing frame having mounting members that enable attachment to the aforementioned lifting mechanism, A traction frame, equipped with a mounting member that enables attachment to the aforementioned device, Equipped with, The towing frame and the towed frame each have a joining surface, and the towed frame can be integrally combined with the towing frame by joining these joining surfaces together. The hitch device is Means for locking the towed frame to the towing frame in the assembled state, A coupling device for connecting the ends of two shafts, the drive output shaft and the driven shaft, comprising: a first casing that supports a first connecting portion connected to the driven shaft via a first rolling bearing; and a second casing that supports a second connecting portion connected to the drive output shaft via a second rolling bearing; It also includes, The towed frame comprises two arms whose free ends are capable of holding the first casing of the coupling device, and the two arms hold the first casing in a predetermined position when the driven shaft is not connected to the drive output shaft, and when the driven shaft is connected to the drive output shaft and the towing frame and the towed frame are combined, their free ends move away from each other and pivot to an open position away from the first casing. Hitch device.

2. The hitch device according to claim 1, wherein the towing frame has a structure comprising a cross member and two leg portions extending from the same side of the cross member, the towed frame has a structure comprising an upper cross member, a lower cross member, and two upright members connecting the end of the lower cross member to the end of the upper cross member, the cross member of the towing frame has at least two centering pins, the upper cross member of the towed frame extends toward the towing frame so as to cover the cross member of the towing frame and is provided with a cap having at least two housing portions configured to receive the at least two centering pins, and the towing frame can be aligned with the towed frame by the at least two centering pins being received in the at least two housing portions of the cap.

3. The hitch device according to claim 2, wherein each of the two legs of the towing frame has a plate slidably attached to its free end so as 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 thereon for accommodating the at least one locking finger.

4. The hitch device according to claim 3, comprising an actuation means for operating the two arms, wherein the actuation means is actuated by the plate to move the arms to the open position when the at least one locking finger is housed in the at least one locking hole.

5. The first casing has fingers that extend laterally, The device comprising the aforementioned drive output shaft is equipped with a guide device, The guide device is A lateral guide plate having a curved upper edge that can engage with the aforementioned finger, A guide arm attached to the horizontal axis by a hinge, Equipped with, The finger is capable of contacting the guide arm so as to be movable along the guide arm, and when the guide arm is operated, the finger moves the first casing toward the device comprising the drive output shaft, and the upper edge contacts the finger and guides the finger to engage with a notch formed in the lateral guide plate. The hitch device according to claim 1.

6. The hitch device according to claim 5, wherein the first casing is provided with the fingers on both sides in the lateral direction, and the guide device is provided with the lateral guide plates on both sides in the lateral direction and the guide arms on both sides in the lateral direction.

7. The hitch device according to claim 5, wherein the guide arm has a locking pin that can engage with a locking device positioned above the lateral guide plate.

8. The locking device has two jaws arranged in the same plane as each of the two lateral guide plates in a plane parallel to the longitudinal axes of the two shafts, the two jaws comprising a lower jaw and an upper jaw attached to and fixed to the second casing, the upper jaw being configured to allow the locking pin to access a housing formed between the two jaws, and to open and close so as to prevent access to the housing when the locking pin moves to a predetermined position in the housing, the locking device pressurizes the upper jaw toward its closed position, the hitch device according to claim 7.

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