Clutch device with lever operation

Abstract

Coupling device (10; 10a) for a hydraulic or pneumatic assembly (11), wherein the coupling device (10) has a housing (12), wherein a first and a second coupling socket (21; 22) are movably received in the housing (12), each of which is movable between a working position, an engagement position and an disengagement position, wherein in the working position a coupling plug is retained in the coupling socket (21; 22), wherein in the engagement position the coupling plug can be engaged into the coupling socket (21; 22), and wherein in the disengagement position the coupling plug can be disengaged from the coupling socket (21; 22), wherein a first rotatable cam (30) is assigned to the first coupling bushing (21), wherein a second rotatable cam (40) is assigned to the second coupling bushing (22), wherein the first and the second cam (30; 40) are each coupled to the assigned coupling bushing (21; 22) in such a way that the assigned coupling bushing (21; 22) can be moved from the working position to the engagement position, whereby the respective coupling plug can be engaged in the coupling bushing (21; 22), wherein the first cam (30) is connected to a first lever arm (31) in a rotationally fixed manner, wherein the second cam (40) is connected to a second lever arm (41) in a rotationally fixed manner, wherein the first and the second lever arm are formed separately (31; 41) from each other, characterized in that a separate third lever arm (50) is rotatably mounted on the housing (12), which is movable between a first actuating position (51), a neutral position (53) and a second actuating position (52), wherein the third lever arm (50) is coupled to the first and the second lever arms (31; 41) in such a way that when the third lever arm (50) moves from the neutral position (53) to the first actuating position (51) only the first clutch bushing (21) can be moved into the engaged position, and when the third lever arm (50) moves from the neutral position (53) to the second actuating position (52) only the second clutch bushing (22) can be moved into the engaged position.

Description

[0001] The invention relates to a coupling device according to the preamble of claim 1.

[0002] Hydraulic quick-release couplings, actuated by a lever arm, are known from US 6,016,835 A1 and EP 38,056 B1. These quick-release couplings have a coupling socket movably mounted in a housing, which is movable between a working position, an engagement position, and a disengagement position. In the working position, the corresponding coupling plug is held in the coupling socket, with the two parts being fluid-tightly sealed against each other. In the engagement position, the coupling plug can be engaged into the coupling socket. In the disengagement position, the coupling plug can be disengaged from the coupling socket. The engagement and disengagement positions can coincide.Furthermore, a rotatable cam is associated with the coupling bushing, which is coupled to the coupling bushing in such a way that the coupling bushing can be moved from the working position to the engaged position, thereby enabling the respective coupling plug to be engaged in the coupling bushing. For the purposes of this application, the coupling bushing is understood to be the female coupling part, and the coupling plug is understood to be the associated male coupling part.

[0003] Furthermore, a hydraulic assembly in the form of a valve block with several valve discs is known from the publication "LUDV Load-Sensing Steuerblick EHM18" by Mannesmann Rexroth AG (order no. RDE 66 128-W; edition 12 / 99). Two quick-release couplings are integrated into each valve disc. Each quick-release coupling is associated with a lever arm that is rotationally fixed to the corresponding cam. By pivoting the lever arm, the coupling bushing can be moved from the working position to the engaged position.

[0004] From DE 196 49 697 A1, a hydraulic assembly in the form of a valve disc is known. Quick-release couplers are integrated into the valve disc, which can be unlocked with an associated hand lever.

[0005] From US patent 7,568,502 B2, a hydraulic assembly with two quick couplers is known, which can be unlocked with a common hand lever that has three positions. In a center position of the hand lever, both quick couplers are locked, while in the two opposite end positions, one associated quick coupler is unlocked in each case.

[0006] US Patent 5,896,889 A discloses a hydraulic quick coupler which can be unlocked by means of a hand lever.

[0007] The advantage of the present invention is that the coupling device is particularly space-saving, so that it can be easily used in a valve block that has a large number of quick-release couplings. Furthermore, the forces required to actuate the quick-release couplings are low.

[0008] According to the independent claim, it is proposed that a separate third lever arm be rotatably mounted on the housing, which is movable between a first actuating position, a neutral position, and a second actuating position. The third lever arm is coupled to the first and second lever arms in such a way that when the third lever arm moves from the neutral position to the first actuating position, only the first clutch bushing can be moved into the engaged position. Similarly, when the third lever arm moves from the neutral position to the second actuating position, only the second clutch bushing can be moved into the engaged position. Thus, only the third lever arm is intended for operation by a single operator, meaning that only this lever arm needs to be large and ergonomically designed. The first and second lever arms, in contrast, can be made much smaller.Because of the alternating actuation of the clutch bushings, only the force required to actuate a single clutch bushing needs to be applied at any given time.

[0009] The dependent claims specify advantageous further developments and improvements of the invention.

[0010] It can be provided that a pressure relief valve with an actuating pin is assigned to each of the first and second coupling bushings, wherein the actuating pin is movable between an open and a closed position, wherein in the open position pressure fluid can escape from the assigned coupling bushing via the pressure relief valve, wherein the pressure relief valve is fluid-tight in the closed position, wherein the first and the second cam are each motionally coupled to the assigned actuating pin and the assigned coupling bushing such that first the assigned actuating pin is moved from the closed to the open position, wherein subsequently the assigned coupling bushing is moved from the working position to the engaged position, whereby pressure fluid can escape from the respective coupling bushing via the pressure relief valve.before the relevant coupling plug can be engaged in the coupling socket. Quick couplings with a pressure relief valve and an actuating pin are known from US 6,016,835 A1 and EP 38,056 B1. Without the pressure relief valve, it is often very difficult to insert the coupling plug into the coupling socket, even when the coupling socket is in the engaged position. A particular advantage of the coupling device according to the invention is that it can be used directly in conjunction with the aforementioned pressure relief valve.

[0011] It can be provided that the first lever arm has a radially outer, free end which rests against the third lever arm at least in the first actuation position, and that the second lever arm has a radially outer, free end which rests against the third lever arm at least in the second actuation position. This minimizes the forces at the contact point between the first and third lever arms, and between the second and third lever arms. The free end of the first and / or the second lever arm is preferably convexly rounded. The corresponding mating surface on the third lever arm is preferably flat.

[0012] It can be provided that the third lever arm has at least one web which extends radially with respect to the axis of rotation of the third lever arm, wherein the free end of the first and second lever arms, respectively, rests against the at least one web in the first and second actuation positions of the third lever arm, respectively. This results in particularly low-friction engagement between the different lever arms. The side surface of the web against which the free end of the first and second lever arms rests is preferably flat. In the region of the at least one web, the third lever arm is preferably T-shaped in cross-section.

[0013] It may be designed so that at least one of the bridges points towards the housing. This minimizes the risk of injury to the operators of the third lever arm.

[0014] It may be provided that a separate sealing screw is screwed into the housing, with the third lever arm rotatably mounted on the sealing screw. This provides the pivot joint for the third lever arm in a particularly simple and cost-effective manner. The sealing screw is preferably screwed into a bore in the housing in which a valve spool or other separate valve component is received. Preferably, the bore is sealed fluid-tight with the sealing screw.

[0015] It can be designed so that the axes of rotation of the first, second, and third lever arms run parallel to each other. This results in particularly low frictional forces when the third lever arm is actuated.

[0016] It can be designed so that the axes of rotation of the first and second lever arms coincide. The corresponding coupling device is particularly space-saving.

[0017] It can be provided that the first cam is rigidly connected to the first lever arm via a first axis, wherein the first axis is rotatably mounted on the housing, and that the second cam is rigidly connected to the second lever arm via a second axis, wherein the second axis is rotatably mounted on the housing or on the first axis. This means that sealing against fluid leakage is only required on these axes. This is particularly cost-effective. Preferably, the first and second cams are arranged inside the housing, with the first and second lever arms arranged outside the housing. Preferably, the second axis is rotatably mounted on the first axis, with the corresponding axes of rotation coinciding.

[0018] It is possible to arrange the first, second, and third lever arms on the same side of the housing. This allows the aforementioned motion coupling between the lever arms to be implemented in a particularly simple manner.

[0019] It may be provided that a seal is arranged between the first shaft and the housing, and / or between the second shaft and the housing, and / or between the first and second shafts. The seal is intended to prevent pressurized fluid from escaping the housing. The proposed seal arrangement is particularly simple and cost-effective.

[0020] It can be provided that the length of the third lever arm is at least twice the length of the first and / or the second lever arm. This results in a particularly space-saving coupling device. The length of a lever arm is preferably measured from its axis of rotation to its radially outermost end.

[0021] It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or on their own, without leaving the scope of the present invention.

[0022] The invention is explained in more detail below with reference to the accompanying drawings. They show: Fig. 1 a perspective view of a hydraulic assembly with a coupling device according to a first embodiment of the invention; Fig. 2 a perspective view of the coupling device according to Fig. 1 without the casing; Fig. 3 another perspective view of the arrangement according to Fig. 2; Fig. 4 a perspective view of a coupling device without the housing according to a second embodiment of the invention; Fig. 5 another perspective view of the arrangement according to Fig. 4; and Fig. 6 a longitudinal section of the first and second axes of the second embodiment of the invention.

[0023] Fig. Figure 1 shows a perspective view of a hydraulic assembly 11 with a coupling device 10 according to a first embodiment of the invention. The hydraulic assembly 11 is designed in the form of a valve disc for a hydraulic valve block. The internal structure of a corresponding valve disc is described, for example, in DE 10 2009 034 616 A1. The hydraulic assembly 11 has two working ports formed by a first and a second coupling bushing 21; 22. The coupling bushings 21; 22 are part of a hydraulic quick-release coupling, which may be designed, for example, according to US 6 016 835 A1.

[0024] The coupling bushings 21 and 22 are both movable relative to the housing 12 of the hydraulic assembly 11 in the direction of movement indicated by reference numeral 25. They can each be moved into a working position, an engaged position, and a disengaged position. In the working position, a matching coupling plug is held in the coupling bushing 21 or 22, so that it is fluid-tightly connected to the hydraulic assembly. In the engaged position, the coupling plug can be engaged in the coupling bushing 21 or 22. In the disengaged position, the coupling plug can be disengaged from the coupling bushing. The engaged and disengaged positions can be formed by one and the same position of the coupling bushing 21 or 22.

[0025] The different positions of the coupling bushings 21; 22 are set with the third lever arm 50. The third lever arm 50 can be moved between three positions 51; 52; 53, which are described in Fig. 1 are each indicated by a dashed line. In the middle neutral position 53, both coupling bushings 21; 22 are in the working position. In the Fig. In the second actuation position of the third lever arm 50 shown in Figure 1, only the second clutch bushing 22 is in the engaged position, while the first clutch bushing 21 is in the working position. In the first actuation position 51 of the third lever arm 50, only the first clutch bushing 21 is in the engaged position, while the second clutch bushing 22 is in the working position.

[0026] The third lever arm 50 is rotatably mounted on a circular cylindrical pin 59 of a separate sealing screw 55, where it is held by a retaining ring 58. The sealing screw 55 is screwed into a bore in the housing 12, in which, for example, a movable valve slide may be accommodated. The sealing screw 55 therefore has two functions: it forms the pivot point of the third lever arm 50 and simultaneously seals the aforementioned bore tightly.

[0027] Furthermore, reference should be made to the first and second lever arms 31; 41, which will be explained in more detail with reference to the following figures.

[0028] Fig. Figure 2 shows a perspective view of the coupling device 10. Fig. 1 without the housing (No. 12 in Fig. 1). Fig. Figure 3 shows another perspective view of the arrangement according to Fig. 2, wherein the viewing directions of the Fig. 2 and Fig. 3 are directed in roughly opposite directions.

[0029] The first and second coupling bushings 21; 22 are identical in design. They are each surrounded by a sleeve 26, which engages with a circular cylindrical outer circumferential surface in a corresponding bore of the housing (No. 12 in Fig. 1) is installed, where it is held in place by a retaining ring. A coil spring 27 is clamped between the sleeve 26 and the associated coupling bushing 21; 22, which holds the coupling bushing 21; 22 in Fig. Presses down on 2 or 3.

[0030] Opposite to the in Fig. At the lower ends of the coupling bushings 21 and 22, a first and a second cam 30 and 40, respectively, are arranged. The first cam 30 is rotatable with respect to the first axis of rotation 33, while the second cam 40 is rotatable with respect to the second axis of rotation 43. The first and second axes of rotation 33 and 43 are arranged parallel to and spaced apart from each other. The third axis of rotation 56 of the third lever arm 50 is arranged parallel to and spaced apart from the first and second axes of rotation 33 and 43.

[0031] The second cam 40 is integrally connected to the second lever arm 41 via a substantially circular cylindrical second axis 44. The second axis 44 is located in the housing (No. 12 in Fig. 1) is rotatably mounted with respect to the second axis of rotation 43. In the area where the second axis 44 protrudes from the housing, a seal 57 is arranged, which comprises an annular circumferential sealing groove in the second axis 44 and a sealing ring (not shown). The second lever arm 41 is arranged outside the housing, with the second cam 40 and the remaining second axis 44 arranged inside the housing. When the second lever arm 41 is in Fig. When the third lever arm 50 is rotated to the right (viewed from position 2), the second cam 40 moves upwards. It first touches the actuating pin 24 on the second clutch bushing 22, and then engages the second clutch bushing 22. Fig. 2 shifts upwards, so that it is moved from the working position to the engaged position.

[0032] Both coupling bushings 21, 22 have an actuating pin 24, which is part of a pressure relief valve 23. The actuating pin 24 is movable between an open and a closed position. When the respective cam 30; 40 does not contact the associated actuating pin 24, the latter is in the closed position, so that the pressure relief valve 23 is fluid-tight. When a cam 30; 40 contacts the associated actuating pin 24, it is pushed into the open position, so that pressurized fluid can escape from the coupling bushing 21; 22 via the pressure relief valve 23. The movement coupling described above between the cams 30; 40, the actuating pins 24 and the coupling bushings 21; 22 results in the coupling bushings 21; 22 must first be relieved of pressure before being moved from the working position to the engagement position.As a result, the coupling plug can be inserted into the coupling socket with little effort.

[0033] The second lever arm 41 extends radially with a constant, rectangular cross-sectional shape with respect to the associated second axis of rotation 43. At its radially outer, free end 43, it has a convex rounded shape. In the Fig. In the second actuation position of the third lever arm 50 shown in Figure 2, the aforementioned free end 42 of the second lever arm 41 rests against a web 54 of the third lever arm 50. The web 54 points towards the housing (No. 12 in Figure 2). Fig. 1) to, forming a flat contact surface for the free end 42 of the second lever arm 41. When the third lever arm is moved from the neutral position (No. 53 in Fig. 1) into the second operating position (No. 52 in Fig. 1) When moved, the bridge 54 comes into contact with the free end 42 of the second lever arm 41, so that the latter is in Fig. Viewed from the third lever arm 50, the second clutch bushing 22 is rotated to the right. As a result, the second clutch bushing 22 is moved from the working position to the engaged position, as described above.

[0034] As in Fig. As can be seen in Figure 3, the first lever arm 31 rests loosely against the bridge 54 in the neutral position of the third lever arm 50, with the first cam 30 positioned at a distance from the first clutch bushing 21. Thus, in the second actuation position of the third lever arm 50, the first clutch bushing 21 is held in its working position by the associated spring 27. The same applies to the second lever arm 41 and the second cam 40.

[0035] In Fig. Figure 3 further shows that the first cam 30 is integrally connected to the first lever arm 31 via a first axis 34. The first and second lever arms 31; 41 are identical, bearing against the web 54 of the third lever arm 50 on opposite sides. The first axis 34 is located in the housing (No. 12 in Fig. 1) rotatably mounted with respect to the assigned first axis of rotation 33. The first cam 30 is thereby in Fig. 1 moved upwards when the first lever arm is in Fig. 3 is rotated to the right when viewed from the first cam 30. This is precisely the case when the third lever arm 50 is moved from the neutral position (No. 53 in Fig. 1) into the first operating position (No. 51 in Fig. 1) is moved. The seal 57 on the first axis 34 is essentially identical in design to the seal on the second axis 44. It also includes an annular circumferential sealing groove in which a sealing ring (not shown) is installed.

[0036] Fig. Figure 4 shows a perspective view of a coupling device 10a without the housing according to a second embodiment of the invention. Fig. Figure 5 shows another perspective view of the arrangement according to Fig. 4, wherein the viewing directions of the Fig. 4 and Fig. 5 are directed in roughly opposite directions.

[0037] The second embodiment is identical to the first embodiment except for the differences described below, whereby reference is made to the embodiment to the Fig. References are made to 1 to 3. Identical or corresponding parts are assigned the same reference numbers.

[0038] The second cam 40 with the second axis 44 and the second lever arm 41 are arranged exactly as in the first embodiment according to the Fig. 1 to 3. The first axis 34, however, is designed as a hollow axis that surrounds the second axis 44, so that the first and second axes of rotation 33; 43 coincide. This reverses the direction of rotation of the first cam 30 compared to the first embodiment, which is necessary to move the first clutch bushing 21 from the working position to the engaged position. The first lever arm 31, which is integrally connected to the first axis 34, now points to the third axis of rotation 56 of the third lever arm 50. A separate first and second web 54a; 54b, respectively, is assigned to the first and second lever arms 31; 41 on the third lever arm 50, each located in the region of the free end 32; 42 of the associated lever arm 31; 41. Accordingly, the position of the first and second actuation positions of the third lever arm 50 does not change compared to the first embodiment.The first and second bridges 54a; 54b each point to the case (No. 12 in . Fig. 1) The side surface of the first and second webs 54a; 54b, against which the first and second lever arms 31; 41 abut, is planar and extends radially with respect to the third axis of rotation 56 of the third lever arm 50. The first and second axes of rotation 33; 43 are parallel and spaced apart from the third axis of rotation 56 of the third lever arm 50.

[0039] It should also be noted that the side web 45 on the second axis 44 extends the second cam 40 in the direction of the second axis of rotation 43. The side web 45 serves as a lateral stop for the first axis 34, thus positively defining its position on the second axis 44.

[0040] It should also be noted that the second lever arm 41 is detachably connected to the second axle 44 so that the first axle 34 can be mounted on the second axle 44. This connection can be secured, for example, with a threaded pin 46 screwed into the hub of the second lever arm 41, the tip of which engages positively with the second axle 44.

[0041] The first axis 34 is provided with a seal 57, which includes an annular circumferential sealing groove in which a (not shown) sealing ring is installed.

[0042] Fig. Figure 6 shows a longitudinal section of the first and second axes 34; 44 of the second embodiment of the invention. The corresponding section plane coincides with the first and second axes of rotation 33; 43. It can be seen that the side web 45 on the second axis 44 forms a lateral stop for the first axis 34. Furthermore, the seal 60 between the first and second axes 34; 44 should be noted. This seal comprises an annular circumferential sealing groove in the first axis 34, into which a sealing ring (not shown) is inserted. The two seals, reference numerals 57 and 60, are arranged at approximately the same position with respect to the first axis of rotation 33.

[0043] Furthermore, reference should be made to the pin 47 on the second axle 44, to which the second lever arm (No. 41 in Fig. 4) is fastened. The pin 47 can be designed in cross-section as a hexagonal or as a multi-wedge profile. The first lever arm 31, on the other hand, is formed integrally with the first axis 34.

[0044] Both in the first embodiment of the invention according to the Fig. 1 to 3 as well as in the second embodiment according to the Fig.In the neutral position 53, the third lever arm 50 has play relative to the first and second lever arms 31 and 41. This play can be eliminated by using adjustment devices. It is conceivable to apply a spring, directly or indirectly, to the first and / or second axis 34 or 44 such that the first or second cam 30 or 40 is pressed against the associated actuating pin 24 with slight preload. The preload is chosen to be so small that the actuating pin 24 remains in the closed position as long as the third lever arm 50 is in the neutral position 53. Furthermore, adjusting screws, wedges, or other movable adjustment devices can be provided to reduce the distance between the web 54 and the first or second lever arm 31 or 41 to almost zero in the neutral position 53 of the third lever arm 50. The aforementioned spring can act on these adjustment devices. Reference sign 10 Coupling device (first embodiment) 10a Coupling device (second embodiment) 11 hydraulic assembly 12 cases 21 first coupling bushing 22 second coupling bushing 23 Pressure relief valve 24 Actuating pins 25 Direction of movement of the coupling bushings 26 sleeve 27 spring 30 first cam 31 first lever arm 32 free end of the first lever arm 33 first axis of rotation of the first lever arm 34 first axis 40 second cam 41 second lever arm 42 free end of the second lever arm 43 second axis of rotation of the second lever arm 44 second axis 45 Side rib on the second axis 46 Threaded pin 47 pins for second lever arm 50 third lever arm 51 First actuation position of the third lever arm 52 second actuation position of the third lever arm 53 Neutral position of the third lever arm 54 Bridge on the third lever arm 54a first jetty 54b second jetty 55 Locking screw (pivot point of third lever arm) 56 third axis of rotation of the third lever arm 57 Seal 58 retaining ring 59 pins on the locking screw 60 Seal

Claims

[1] Coupling device (10; 10a) for a hydraulic or pneumatic assembly (11), wherein the coupling device (10) has a housing (12), wherein a first and a second coupling socket (21; 22) are movably received in the housing (12), each of which is movable between a working position, an engagement position and an disengagement position, wherein in the working position a coupling plug is retained in the coupling socket (21; 22), wherein in the engagement position the coupling plug can be engaged into the coupling socket (21; 22), and wherein in the disengagement position the coupling plug can be disengaged from the coupling socket (21; 22), wherein a first rotatable cam (30) is assigned to the first coupling bushing (21), wherein a second rotatable cam (40) is assigned to the second coupling bushing (22), wherein the first and the second cam (30; 40) are each coupled to the assigned coupling bushing (21; 22) in such a way that the assigned coupling bushing (21; 22) can be moved from the working position to the engagement position, whereby the respective coupling plug can be engaged in the coupling bushing (21; 22), wherein the first cam (30) is connected to a first lever arm (31) in a rotationally fixed manner, wherein the second cam (40) is connected to a second lever arm (41) in a rotationally fixed manner, wherein the first and the second lever arm are formed separately (31; 41) from each other, characterized by, that a separate third lever arm (50) is rotatably mounted on the housing (12), which is movable between a first actuating position (51), a neutral position (53) and a second actuating position (52), wherein the third lever arm (50) is coupled to the first and the second lever arms (31; 41) in such a way that when the third lever arm (50) moves from the neutral position (53) to the first actuating position (51) only the first clutch bushing (21) can be moved into the engaged position, and when the third lever arm (50) moves from the neutral position (53) to the second actuating position (52) only the second clutch bushing (22) can be moved into the engaged position. [2] Coupling device according to claim 1, wherein the first and second coupling bushings (21; 22) are each associated with a pressure relief valve (23) with an actuating pin (24), wherein the actuating pin (24) is movable between an open and a closed position, wherein in the open position pressure fluid can escape from the associated coupling bushing (21) via the pressure relief valve (23), wherein the pressure relief valve (23) is fluid-tight in the closed position, wherein the first and second cams (30; 40) are each coupled to the associated actuating pin (24) and the associated coupling bushing (21; 22) in such a way that first the associated actuating pin (24) is moved from the closed to the open position, and subsequently the associated coupling bushing (21; 22) is moved from the working position to the engaging position, allowing pressure fluid to escape from the respective coupling bushing (21; 22) via the pressure relief valve (23) before the respective coupling plug can be engaged in the coupling bushing (21; 22). [3] Coupling device according to one of the preceding claims, wherein the first lever arm (31) has a radially outer free end (32) which rests against the third lever arm (50) at least in the first actuation position (51), wherein the second lever arm (41) has a radially outer free end (42) which rests against the third lever arm (50) at least in the second actuation position (52). [4] Coupling device according to claim 3, wherein the third lever arm (50) has at least one web (54; 54a; 54b) which extends radially with respect to the axis of rotation (56) of the third lever arm (50), wherein the free end (32; 42) of the first and second lever arms (31; 41) respectively bears against the at least one web (54; 54a; 54b) in the first and second actuation positions (51; 52) of the third lever arm (50). [5] Coupling device according to claim 4, wherein the at least one web (54; 54a; 54b) points towards the housing (12). [6] Coupling device according to one of the preceding claims, wherein a separate locking screw (55) is provided which is screwed into the housing (12), wherein the third lever arm (50) is rotatably mounted on the locking screw (55). [7] Coupling device according to one of the preceding claims, wherein the axes of rotation (33; 43; 56) of the first, second and third lever arms (31; 41; 50) are parallel to each other. [8] Coupling device according to one of the preceding claims, wherein the axes of rotation (33; 43) of the first and second lever arms (31; 41) coincide. [9] Coupling device according to claim 7 or 8, wherein the first cam (30) is fixedly connected to the first lever arm (31) via a first axis (34), wherein the first axis (34) is rotatably mounted on the housing (12), wherein the second cam (40) is fixedly connected to the second lever arm (41) via a second axis (44), wherein the second axis (44) is rotatably mounted on the housing (12) or on the first axis (34). [10] Coupling device according to one of the preceding claims, wherein the first, second and third lever arms (31; 41; 50) are arranged on the same side of the housing (12). [11] Coupling device according to claim 10 in conjunction with claim 9, wherein a seal (57; 60) is arranged between the first axis (34) and the housing (12) and / or the second axis (44) and the housing (12) and / or the first and the second axis (34; 44). [12] Coupling device according to one of the preceding claims, wherein the length of the third lever arm (50) is at least twice as long as the length of the first and / or the second lever arm (31; 41).

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