Clutch device

Abstract

The invention relates to a clutch device (KE4) for selectively transmitting a torque, in particular for a gear-shifting system for a bicycle, the clutch device comprising a first and a second clutch half (402, 403), which can be brought into a closed state, an intermediate state, and an open state by an actuating device (410, 418-422). In the intermediate state, only a torque which does not exceed a determined threshold torque can be transmitted by the clutch device (KE4). The clutch device (KE4) can in particular be realised by an interlocking connection between the two clutch halves (402, 403), which connection can be disconnected in the intermediate state when a torque which is greater than the threshold torque is applied to the first clutch half (402). In this manner, the operating torque, which is applied to the clutch device (KE4) by the rider, is used for the shifting process, and so only a relatively low actuating force has to be applied by the actuating device (410, 418-422). Opening of the clutch device (KE4) and thus a shifting process under load is also made possible thereby.

Description

[0001] Coupling device

[0002] Description

[0003] The entire content of priority application DE 10 2023 211 468.2 is hereby incorporated by reference into the present application.

[0004] The invention relates to a clutch device for a bicycle and a gearshift for a bicycle with such a clutch device.

[0005] The bicycle can also be an electric bicycle. Electric bicycles have an auxiliary motor that assists the cyclist's pedaling motion. Gears on a bicycle, including an electric bicycle, ensure that pedaling can be achieved at a roughly constant cadence over a wide speed range.

[0006] According to the state of the art, the following gear shifts are currently used on bicycles and electric bicycles:

[0007] 1) Hub gears

[0008] 2) Derailleur gears

[0009] 3) Bottom bracket gears

[0010] When it comes to tackling a variety of tasks within the diverse environments in which bicycles are used, a shiftable transmission is indispensable in most cases. While a single-speed, i.e. a bicycle with a non-shiftable gear ratio, may be sufficient in urban traffic without hills, their use reaches its limits over longer distances, such as those prevalent in rural areas. Steep climbs or descents in mountain biking, heavy loads in the transport of people or goods, ergonomic aspects of long-distance rides, or ever-increasing maximum speeds require the rider to be able to change the ratio of the applied torque and speed while riding. This allows the rider to adapt the cadence and pedal force to the respective situation.

[0011] In a bicycle, the aforementioned transmissions are usually designed in three different ways: as a switchable traction transmission, planetary gear transmission or spur gear transmission.

[0012] Planetary gears are usually used within the hub shell on the rear wheel, whereas spur gears are often located near the bottom bracket shaft.

[0013] Drivetrains predominantly connect the bottom bracket spindle to the rear wheel hub, particularly in the form of a derailleur, as described below.

[0014] Over the past sixty years, chain drives with gear shifting at the rear wheel axle have become increasingly popular on bicycles. A rotating bottom bracket with one or more chainrings is mounted on the frame, which forms the load-bearing part of the bicycle with all its attachment points for the front fork, seat post, and rear wheel. A cassette consisting of up to thirteen sprockets of different sizes is mounted on the rear wheel hub. A rear derailleur is attached to a dropout connecting the frame to the rear axle. Its job is to guide the chain onto the cassette sprockets and enable gear shifting. Additionally, a front derailleur, usually mounted on the seat tube, allows switching between different chainrings at the bottom bracket. Bicycles with a gear shifting system like the one described above are generally referred to as derailleur bicycles.

[0015] Because the components of a derailleur bike are mounted on the outside of the frame by design, they are particularly exposed to environmental influences, resulting in increased wear and tear and, consequently, a significant drop in efficiency after a short period of use. The resulting short maintenance intervals, especially on bikes with auxiliary drive, are very costly due to the necessary replacement of the torque-transmitting components of the traction drive. In addition, the derailleur, located in an exposed position on the rear wheel, is at increased risk of damage from falls or similar incidents.

[0016] In so-called hub gears and gears located near the bottom bracket (hereinafter referred to as bottom bracket gears), the components are protected from external influences within a housing. A hub gear usually has a single or multiple planetary gears connected in series, which share the rotational axis of the rear wheel as a coaxial rotational axis for the individual gear stages. Hub gears are also often called gear hubs.

[0017] Hub gears are switchable planetary gears built into the hub shell of the rear wheel. The hub gears are enclosed in a housing, isolated from the outside environment, and are therefore largely maintenance-free. However, the disadvantage of hub gears is the heavy weight on the rear wheel, which leads to unfavorable weight distribution. The heavy weight on the rear wheel hub is a nuisance not only when carrying the bike, but also when cornering or during aggressive off-road riding.

[0018] Another disadvantage of the hub gears available on the market today is the lack of shifting capability under load. A cyclist who is pedaling uphill under load, for example, in sixth gear with high torque and wants to shift down a gear, must first release the pedals with standard hub gears to enable the shift to fifth gear.

[0019] The rider's torque is usually transmitted via a traction drive to the input shaft of the gear hub, converted by the planetary gears, and transferred to the hub shell, which then serves as the output shaft of the transmission. The input shaft is also often called the driver. The spokes attached to the hub shell connect the gear to the rim, which transmits the torque to the road surface via the tire. The traction drive design, combined with a toothed belt, requires significantly less maintenance than a chain and is better protected against external influences. Compared to hub gears, derailleur gears offer improved shifting under load.As already mentioned, derailleur systems on the rear wheel have multiple chain sprockets arranged in a stack, with the front derailleur guiding the chain to a specific sprocket depending on the selected gear, thus achieving a specific gear ratio. This gear change is possible with a derailleur system even under load.

[0020] Derailleur gears were historically developed to transmit exclusively the mechanical pedaling power exerted by a human to the rear wheel. If the bicycle also has an auxiliary drive, this is usually located at the bottom bracket in the case of the electric bicycles considered here. With these so-called mid-drive motors, the power of the cyclist at the crank and the power of the electric motor are combined and transmitted to the gears, which can result in very high power transmission. Today, derailleur gears or hub gears are typically used in this configuration because there isn't enough space at the bottom bracket for a gear system.

[0021] As already mentioned, derailleur systems have the disadvantage that their components—namely, the pinions on the rear wheel hub, at least one chainring, and the chain and derailleur—are unprotected and therefore easily contaminated. Wear is significantly increased due to the high power transmission required when an auxiliary drive is present. Derailleur systems are therefore comparatively maintenance-intensive. The maintenance interval for an electric bike with derailleur systems can be between 600 and 1200 km. This is considered a disadvantage. Instead of, or in combination with, derailleur systems, electric bikes also use hub gears on the rear wheel.

[0022] A more favorable weight distribution is achieved when the gear shift is positioned centrally in the bike, as is the case with bottom bracket gears, for example. However, current bottom bracket gear shifts are quite large, leaving no space around the bottom bracket for the electric motor. Furthermore, bottom bracket gear shifts are already so heavy that the additional weight of an auxiliary drive would result in an electric bike that would be too heavy for everyday use or for continuing to ride with a dead battery. In addition, the shifting performance under load with bottom bracket gear shifts is just as poor as with hub gears.

[0023] Bottom bracket gears are usually spur gears, as known, for example, from DE 10 2009 060 484 B4, whose housings are attached to the main frame of the bicycle. This utilizes a protected and compact installation space around the bottom bracket axle to achieve the transmission's function. The input shaft of a bottom bracket gear is usually directly connected to the bicycle's cranks and pedals. A transmission mechanism also transmits torque to the rear wheel on the output shaft. This type of bicycle transmission has the advantage that the weight of the transmission is located at a central and low point, which has a positive effect on the center of gravity and thus on the handling. However, for the reasons stated above, the sporty use of a bicycle with bottom bracket gears or hub gears is difficult.

[0024] In gear drives, the various gear ratios, referred to below as gears or gear stages, are achieved by combining several gear pairs or their individual ratios. Since in spur and planetary gear drives all gears on each input or intermediate shaft are usually in mesh with the corresponding gear on the following intermediate or output shaft at all times, one gear in each pair must be able to rotate freely on its shaft without transmitting torque. Using switchable clutches, individual ones of these free gears can be connected to the corresponding shaft or a component downstream in the torque flow in a torque-transmitting manner. The activation of individual clutches thus transmits the torque through the gear pairs, which together result in the desired overall gear ratio of a gear.

[0025] The couplings can be designed as radial or axial couplings, usually as positive-lock couplings, which predominantly transmit torque in only one direction of rotation, following the freewheel principle. The function of such a radial coupling is clearly visible as an example in Figures 9 and 10 of WO 98 / 52817 A1. Switchable axial couplings are usually designed as claw couplings and each have an axially movable and an axially fixed component, as also shown in Figures 6 and 7 of WO 98 / 52817 A1.

[0026] Compared to a radial clutch with pawls, the face gearing of an axial clutch offers the advantage of a significantly larger force-transmitting surface within the same installation space. This advantageously reduces surface pressure.

[0027] The control of the axial clutches is carried out by a so-called actuating element, hereinafter also referred to as the selector shaft or selector drum, as shown, for example, in WO 98 / 52817 A1. This is a cylindrical body in which spiral grooves as well as elevations and depressions are embossed. See also Fig. 15 of WO 98 / 52817 A1. The selector drum is usually arranged so as to be rotatable in a fixed hollow axle, hereinafter referred to as the main axle, whereby the angular position of the selector drum in relation to the main axle defines the states of the individual clutches (active, inactive) for the gears. This angular position of the hollow axle can be controlled by the rider, either mechanically via Bowden cables or electrically via an actuator, from the handlebars of the bicycle.

[0028] If we consider a single axial clutch according to WO 98 / 52817 A1, the two halves of the face gearing are usually held together by a spring when engaged. To separate the axial clutch, the spring-loaded clutch half is usually moved axially by a sliding ring connected to the shift drum so that the clutch is opened. When shifting under load, certain functional surfaces of the movable clutch half are in frictional contact with adjacent surfaces of the fixed clutch half. In order to shift from one gear to another under load, the static friction must first be overcome. The movable clutch component must then be moved further under the influence of sliding friction. Due to the high frictional forces, shifting under load is difficult or even impossible.The object of the present invention is therefore to provide a clutch device with improved switching capability under load.

[0029] This object is achieved by a clutch device according to claim 1 or by a transmission for a bicycle according to claim 21 with such a clutch device. Advantageous developments of the invention are contained in the subclaims.

[0030] The coupling device in question is intended for the selective transmission of torque from a first shaft or hub to a second shaft or hub, in particular for a transmission for a bicycle. It comprises a first coupling half, which is non-rotatably connected to the first shaft or hub, a second coupling half, which is non-rotatably connected to the second shaft or hub, and an actuating device.

[0031] According to the invention, the clutch device can be brought into several states by actuating the actuating device, namely into a closed state in which a torque can be transmitted from the first clutch half to the second clutch half in both directions of rotation and in which, in particular, the first clutch half is connected to the second clutch half in a rotationally fixed manner, into at least one intermediate state in which, in a first direction of rotation, a torque which is less than or equal to a threshold torque dependent on the intermediate state and no torque which is greater than the threshold torque of the intermediate state, and in a second direction of rotation opposite to the first direction of rotation, essentially no torque can be transmitted from the first clutch half to the second clutch half, and into an open state,in which no torque can be transferred from the first coupling half to the second coupling half in any direction of rotation.

[0032] The clutch device according to the invention can thus be brought into at least one intermediate state in a first partial shifting process by actuating the actuating device before a shifting process in which the clutch device is to be brought from the closed to the open state. This first partial shifting process can take place with a relatively low actuating force. If the intermediate state is set up such that its threshold torque is below the instantaneous operating torque, this operating torque can therefore no longer be transmitted between the first clutch half and the second clutch half. An operating torque is understood to mean the torque with which the first clutch half is acted upon at the time in question, in particular by the operation of the bicycle with the gearshift which contains the clutch device.

[0033] The clutch device can then be brought into the open state in a second partial shifting operation without having to overcome additional forces that would act during torque transmission between the first and second clutch halves, particularly frictional forces. Thus, only a relatively low actuation force is required in the second partial shifting operation.

[0034] During the described switching process from the closed to the open state of the clutch device, the invention thus utilizes the operating torque to execute the switching process. Even if the clutch device is subjected to a high operating torque, only a relatively low actuating force needs to be applied by the actuating device during the entire switching process.

[0035] The described switching process from the closed to the open state of the clutch device thus facilitates switching under load, in particular, and thus achieves the object of the invention. The fact that the operating torque is simultaneously utilized for the switching process contributes to the fact that only a relatively low actuating force needs to be applied by the actuating device. This is particularly advantageous when the actuating device is driven by an electric motor. This can then be designed to be correspondingly small and also consumes correspondingly little electrical energy.

[0036] The at least one intermediate state is preferably used only during a shifting operation, specifically in the manner just described. Otherwise, the clutch device is preferably in the closed or open state.

[0037] In a preferred embodiment of the invention, the clutch device can be brought into a plurality of intermediate states with different threshold torques by actuating the actuating device. In this way, the at least one intermediate state into which the clutch device is brought in the first partial shifting operation can be specifically selected such that its threshold torque is slightly below the current operating torque. This allows the shifting behavior of the clutch device to be adapted to the current load conditions. The disengagement of the clutch device and thus the entire shifting operation can thus be carried out quickly and reliably.

[0038] In a preferred variant of the previously described embodiment of the invention, the clutch device can be brought, by actuating the actuating device, from the closed state successively, in particular continuously, into the plurality of intermediate states and finally into the open state, with the threshold torques of the intermediate states decreasing monotonically, and in the reverse order, from the open state to the closed state. This facilitates the selection of the intermediate state to be set in each case, for example by appropriately adjusting the required actuating force of the actuating device, which can also decrease monotonically, in particular continuously.

[0039] In a further preferred embodiment of the invention, the first coupling half and the second coupling half are movable relative to each other.Furthermore, they are designed to produce a separable positive connection with one another, in particular by means of claws on the first coupling half and on the second coupling half which can be brought into engagement with one another, wherein the positive connection is produced in the closed state of the coupling device, is produced in the at least one intermediate state of the coupling device when the first coupling half is subjected to a torque which is less than or equal to the threshold torque of the at least one intermediate state, and is separable by subjecting the first coupling half in the first direction of rotation to a torque which is greater than the threshold torque of the at least one intermediate state, and is separated in the open state of the coupling device.

[0040] The clutch device according to the invention can be easily implemented by a positive connection between the first and second clutch halves. In particular, the behavior of the clutch device according to the invention in the at least one intermediate state can be easily implemented by separating the positive connection when the threshold torque is exceeded.

[0041] In a preferred variant of the previously described embodiment of the invention, the coupling device can be brought into the open state, into the at least one intermediate state and / or into the closed state by the actuating device by a respective different restriction of the possible positions of a movable coupling half, which is one of the first coupling half and the second coupling half, to a specific position or a specific range of positions relative to the other coupling half.

[0042] The movable coupling half is preferably movable in the axial direction.

[0043] In this variant, the actuating device thus controls at least one state, preferably several states, and more preferably all states of the coupling device by restricting the possible positions of the movable coupling half. This state or these states can be partially predetermined directly by restricting these possible positions.

[0044] This represents a further simple possibility for implementing the coupling device according to the invention. In a preferred variant of the variant described above, the coupling device can be brought into the open state by restricting the possible positions of the movable coupling half to a position in which the positive connection is separated, can be brought into the at least one intermediate state by restricting the possible positions of the movable coupling half to a range between a position in which the positive connection is established and a position in which the positive connection is separated, and / or can be brought into the closed state by restricting the possible positions of the movable coupling half to a position in which the positive connection is established.

[0045] In this variant, the restriction of the range of possible positions of the movable coupling half directly determines the respective state(s) of the positive connection between the two coupling halves and thus the respective state(s) of the coupling device. This results in particularly simple control of the coupling device.

[0046] In a preferred variant of the previously described variant, the coupling device has one or two movable limiting devices, wherein the range of possible positions of the movable coupling half can be determined by the area between one limiting device and the other coupling half or by the area between the two limiting devices. In the first alternative, the other coupling half thus functions as a second, but preferably non-movable, limiting device.

[0047] In this way, the coupling device can be controlled simply and directly by the actuating device by controlling one or both limiting devices.

[0048] In a preferred variant of the three variants described above, the coupling device further comprises a spring which is pre-tensioned in the at least one intermediate state, wherein the spring, when pre-tensioned, can generate a spring force by which an actuating force acting in the closing direction of the positive connection can be generated directly or indirectly.

[0049] The desired behavior of the clutch device in at least one intermediate state can be easily achieved by applying the actuating force. For this purpose, an opening force can be generated from the operating torque, which acts in the opening direction of the positive connection and thus counteracts the actuating force. If the threshold torque of the intermediate state is dimensioned such that, when the operating torque exceeds the threshold torque, the opening force also exceeds the actuating force, the positive connection opens under this condition, and the operating torque can no longer be transmitted via the clutch device.

[0050] Since the actuating force generated by the spring force is preferably approximately the same order of magnitude as the opening force generated by the operating torque, and the operating torque can be relatively high, particularly in a bicycle gear hub, the spring is preferably designed to be relatively hard. The spring is preferably a compression spring. However, depending on the design, it can also be designed as a tension spring, torsion spring, elastomer spring, or another type of spring.

[0051] In a preferred variant of the previously described variant, the spring is supported at a first end on the movable coupling half and at a second end, opposite the first end, on a component that is immovable relative to the other coupling half.

[0052] In an alternative preferred variant of the two previously described variants, the spring is supported at a first end on the movable coupling half and at a second end, opposite the first end, on a limiting device.

[0053] Both alternative spring support variants allow the desired actuating force acting in the closing direction of the positive connection to be generated simply and directly. In the second of these alternative variants, the actuating force can also be varied by shifting the limiting device against which the spring rests at its second end.

[0054] In any case, only a single spring is required to implement the coupling device in the last-described embodiment of the invention. The term "spring" is generally understood here as a device that generates a spring force. However, the "single spring" can also technically be implemented by a plurality of, preferably smaller, springs, which are preferably connected in parallel, i.e., by an "array" of springs.

[0055] In a further preferred embodiment of the invention, the clutch device has a first spring, and the actuating device is configured to preload the first spring. Furthermore, the clutch device can be brought into the open state by reducing the preload of the first spring by the actuating device, brought into the at least one intermediate state by increasing the preload of the first spring by the actuating device, wherein the degree of preload of the first spring determines the threshold torque of the intermediate state, and brought into the closed state by further increasing the preload of the first spring by the actuating device.

[0056] In this embodiment of the invention, the actuating device thus controls the various states of the clutch device indirectly via the preload of the first spring.

[0057] This also represents a simple way to implement the clutch device according to the invention. In particular, only a single variable needs to be influenced, namely the preload of the first spring, and not, as in at least one of the previous embodiments, two variables, namely, in particular, the positions of two limiting devices.

[0058] In a preferred variant of the previously described embodiment of the invention, a first spring force can be generated by the first spring when it is pretensioned, by which a first actuating force acting directly or indirectly in the closing direction of the positive connection can be generated.

[0059] This allows the desired control of the states of the clutch device to be implemented in a simple manner. Similar to what was explained above, an opening force can be generated from the operating torque, which acts in the opening direction of the positive connection and thus counteracts the first actuating force. If the threshold torque of the at least one intermediate state and the first actuating force generated by the first spring force are dimensioned such that, when the operating torque exceeds the threshold torque, the opening force also exceeds the first actuating force, the positive connection opens under this condition, and the operating torque can no longer be transmitted via the clutch device, thereby achieving the desired behavior of the clutch device in the at least one intermediate state.

[0060] This also prevents the transmission from jamming during the shifting process because two parallel gear stages are engaged simultaneously. Geometric overdetermination is prevented.

[0061] Furthermore, the first actuating force can be increased to such an extent that it exceeds any desired opening force value, thus ensuring that the positive connection is always closed, thereby achieving the desired behavior of the coupling device in the closed state. This can preferably be achieved by designing the first spring as a compression spring and preloading it to such an extent that it locks, whereby the first spring force and thus also the first actuating force theoretically become infinitely large.

[0062] Since the first actuating force generated by the first spring force is preferably at least of the same magnitude as the opening force generated from the operating torque, and the operating torque can be relatively high, particularly in a bicycle gear hub, the first spring is preferably designed to be relatively hard. As already mentioned, the first spring is preferably a compression spring. However, depending on the design, it can also be designed as a tension spring, torsion spring, elastomer spring, or another type of spring.

[0063] Finally, the first actuating force can be reduced to such an extent that the positive connection is always open, thereby achieving the desired behavior of the coupling device in the open state. This can preferably be achieved by designing the first spring as a compression spring and completely relaxing it, whereby the first spring force and thus also the first actuating force become equal to or almost zero.

[0064] In a preferred variant of the variant described above, the first spring force acts in a direction substantially equal to the closing direction of the positive connection between the first coupling half and the second coupling half, in a direction substantially opposite to this closing direction or in a direction substantially orthogonal to this closing direction.

[0065] The first spring force can thus act in the same direction as the first actuating force, which always acts in the closing direction of the positive connection, but also in other directions. This provides additional degrees of freedom in the design of the coupling device for the arrangement of the first spring relative to the positive connection, and in particular relative to the movable coupling half, in that the first spring can also be arranged in a direction other than the closing direction of the positive connection.

[0066] In a preferred variant of the previously described variant, the first spring force can be deflected by a lever mechanism, a wedge mechanism and / or a link guide in order to generate the first actuating force.

[0067] By redirecting the first spring force by the aforementioned machine elements, the aforementioned arrangement of the first spring can be realized in a direction other than the closing direction of the positive connection. Preferably, the first spring force can be redirected in a direction substantially opposite to the closing direction by a lever mechanism, and the first spring force can be redirected in a direction substantially orthogonal to the closing direction by a wedge mechanism and / or a slotted guide.

[0068] In a preferred variant of the previously described variants with a first spring, the coupling device additionally has a second spring, which is preloaded in the closed state and in the at least one intermediate state of the coupling device. When preloaded, the second spring can directly or indirectly generate a second actuating force acting in the opening direction of the positive connection.

[0069] The second actuating force thus counteracts the first actuating force. In particular, if the first spring is not pre-tensioned or is only slightly pre-tensioned, the second actuating force can exceed the first actuating force and thus cause the positive connection to open. The second spring can therefore assist in bringing the clutch device into the open state. This is particularly important when the clutch device is to be opened but is not currently subjected to an operating torque, for example because the bicycle is stationary (i.e. when shifting gears while stationary) or because the rider is riding but not pedaling. In this case, the positive connection can also be opened solely by the second spring.In addition, the second spring can ensure that the clutch device does not automatically change from the open state to an intermediate state due to dynamic factors such as inertia or vibration.

[0070] In a preferred variant of the previously described variant, the first spring has a greater spring constant than the second spring.

[0071] To support the opening or ensure the open state of the positive connection, generally only a relatively low second actuating force is required. The second spring can therefore be designed to be weaker than the first spring. This also has the advantage that the actuating device, which must preload the first spring and thereby work against the second actuating force, is not subjected to more than necessary load.

[0072] In the last-described variants, two springs are therefore required to implement the coupling device. This eliminates the need for any limiting devices required in the first-described embodiment of the invention to determine the range of possible positions of the movable coupling half and to control the latter. However, it is also possible to implement the coupling device with two springs and one limiting device. In a further preferred embodiment of the invention, the first coupling half has at least one first substantially planar drive surface, and the second coupling half has at least one second substantially planar drive surface, which can be brought into contact with one another to establish the positive connection in the first direction of rotation.In this case, the at least one first drive surface and / or the at least one second drive surface is inclined relative to a radial plane through which the axis of rotation of the first coupling half or of the second coupling half runs and which intersects the respective drive surface, on a side facing the second coupling half against the first direction of rotation and on a side facing away from the second coupling half in the first direction of rotation. In this way, the at least one first drive surface and / or the at least one second drive surface can, in the at least one intermediate state, cause a separation of the positive connection between the first coupling half and the second coupling half when the first coupling half is subjected to a torque in the first direction of rotation that is greater than the threshold torque of the at least one intermediate state.

[0073] The at least one first and the at least one second drive surface are preferably side surfaces of teeth (also referred to as claws) of circumferentially arranged, end-face toothings (i.e. the teeth extend from the tooth roots to the tooth tips in the axial direction) of the first and second coupling halves, respectively. Such end-face toothing is also called face toothing. When the coupling device is closed, the end-face teeth or claws engage with one another and thus create the positive connection between the first and second coupling halves. The at least one first and the at least one second drive surface then bear against one another and transmit a torque in the first direction of rotation.

[0074] In a conventional claw coupling, the side surfaces of the front teeth are not inclined relative to the radial plane mentioned, but lie completely in this radial plane.

[0075] The inclination of the drive surfaces relative to the radial plane according to the invention can cause the first and second drive surfaces to "slide" against each other when a torque, i.e., the operating torque, is applied to the first clutch half in the first direction of rotation. The first and second drive surfaces thereby form a wedge gear. In other words, the clutch device can thus function as a slip clutch in the first direction of rotation in the at least one intermediate state.

[0076] If at least the first or the second coupling half is axially displaceable, this sliding of the drive surfaces against each other can cause an axial movement of the two coupling halves away from each other and thus an opening of the positive connection. This is counteracted by the frictional force due to the contact between the at least one first and the at least one second drive surface, as well as possibly the actuating force generated by the spring or the first spring. Overall, therefore, when a certain torque applied to the first coupling half is exceeded, the positive connection opens. This torque represents the threshold torque for the intermediate state of the coupling device thus established.

[0077] In a preferred variant of the previously described embodiment of the invention, the angle of inclination of the at least one first drive surface and / or the at least one second drive surface relative to the respective radial plane is 2 to 10 degrees, preferably 4 to 7 degrees, more preferably approximately 5 degrees.

[0078] Corresponding tests have shown that with these preferred value ranges or values ​​for the angles of inclination of the drive surfaces, it is possible to ensure that the clutch device does not open too easily or too heavily, ie appropriate threshold torques of the intermediate states can be achieved in this way.

[0079] In a further preferred embodiment of the invention, the first coupling half has at least one first substantially planar freewheel surface and the second coupling half has at least one second substantially planar freewheel surface, which can be brought into contact with one another in the second direction of rotation to establish the positive connection. The at least one first freewheel surface and / or the at least one second freewheel surface are inclined in the first direction of rotation on a side facing the second coupling half and counter to the first direction of rotation on a side facing away from the second coupling half, relative to a radial plane through which the axis of rotation of the first coupling half or the second coupling half runs and which intersects the respective freewheel surface.In this way, the at least one first freewheel surface and / or the at least one second freewheel surface in the at least one intermediate state can cause a separation of the positive connection between the first clutch half and the second clutch half when a torque is applied to the first clutch half in the second direction of rotation.

[0080] The at least one first and the at least one second freewheel surface are preferably not provided for transmitting a torque between the first and the second clutch half, but for realizing a freewheel function in the second direction of rotation.

[0081] The inclination of the freewheel surfaces relative to the respective radial plane according to the invention can also ensure that, when the first clutch half is subjected to a torque in the second direction of rotation, the at least one first and the at least one second freewheel surface can "slide" against one another. In other words, the clutch device can thus also function as a slip clutch in the second direction of rotation in the at least one intermediate state. In contrast to the first direction of rotation, however, the slip clutch in the second direction of rotation is preferably designed to become effective even at very low torques. Thus, the actual clutch function of the clutch device is preferably only present in the first direction of rotation.

[0082] In a preferred variant of the previously described embodiment of the invention, the angle of inclination of the at least one first freewheel surface and / or the at least one second freewheel surface relative to the respective radial plane is 35 to 75 degrees, preferably 45 to 65 degrees, more preferably approximately 55 degrees.

[0083] These preferred value ranges or values ​​for the angles of inclination of the freewheel surfaces are clearly significantly greater than the above-mentioned preferred value ranges or values ​​for the angles of inclination of the drive surfaces. The at least one first and the at least one second freewheel surface thus slide against one another significantly faster in the second direction of rotation than the drive surfaces in the first direction of rotation. In this way, the desired freewheel function in the second direction of rotation can be easily implemented. The sliding of the freewheel surfaces in the second direction of rotation occurs, in the at least one intermediate state, preferably against the actuating force generated by a spring and acting in the closing direction of the positive connection.This actuating force preferably always re-engages the first and second clutch halves after the freewheel surfaces have slipped in the second direction of rotation, so that torque can continue to be transmitted in the first direction of rotation.

[0084] The invention further relates to a gearshift for a bicycle with at least one clutch device according to the invention.

[0085] In a preferred embodiment, the transmission according to the invention comprises at least one partial transmission, wherein each partial transmission comprises an idler gear shaft on which at least one idler gear is mounted, at least one clutch device according to the invention, and a gear shaft on which at least one gear is mounted in a rotationally fixed manner, and wherein the at least one idler gear meshes with the at least one gear. In this case, a torque can be selectively transmitted from the at least one idler gear to the idler gear shaft or vice versa by the at least one clutch device in order to activate a gear stage of the respective partial transmission.

[0086] The use of the clutch device according to the invention in a transmission for a bicycle makes it possible, as explained above, to shift the transmission even under load. This increases riding comfort for the cyclist, as they no longer have to briefly interrupt their pedaling action when shifting or at least relieve the pressure on the pedals while pedaling in order to complete the shifting operation. Especially when riding uphill, and especially when out of the saddle, such an interruption or relief of the pedals is difficult or at least disrupts the pedaling rhythm, thus throwing the cyclist off-kilter and can cost valuable time, particularly in cycling competitions. Automatic shifting can also be implemented.

[0087] In a preferred variant of the previously described embodiment, the transmission according to the invention comprises a first sub-transmission and a second sub-transmission, which are connected in series to transmit torque from the first sub-transmission to the second sub-transmission. This represents an effective way of combining different gear ratios of the two sub-transmissions into one gear ratio of the entire transmission, thus generating a wide range of gear ratios for the transmission.

[0088] Embodiments of the invention will be explained in more detail below with reference to the drawings. They show:

[0089] Fig. 1 a bicycle without auxiliary drive in side view with a

[0090] Hub gears and a belt drive;

[0091] Fig. 2 is a front view of the rear wheel of the bicycle according to Fig. 1 with

[0092] Hub gear in section AA;

[0093] Fig. 3 is a schematic sectional view through the hub gear of the bicycle according to Fig. 1 in section BB with a first and a second embodiment of a coupling device according to the invention;

[0094] Fig. 4 is a schematic sectional view of a third embodiment of a coupling device according to the invention a) in the open state, b) in an intermediate state and c) in the closed state;

[0095] Fig. 5 is a schematic sectional view of a fourth embodiment of a coupling device according to the invention;

[0096] Fig. 6 is a schematic sectional view of a fifth embodiment of a coupling device according to the invention;

[0097] Fig. 7 is a schematic sectional view of a sixth embodiment of a coupling device according to the invention;

[0098] Fig. 8 is a perspective view of a first coupling half of a coupling device according to the invention;

[0099] Fig. 9 shows an enlarged section of the spur gearing of the first

[0100] Coupling half according to Fig. 8.

[0101] Fig. 1 shows a side view of a bicycle without auxiliary drive. It shows the following components: handlebar 1 with stem, brake levers, and grips, suspension fork 2 with front wheel, crankset 3 with pedals and pulley, a simplified representation of a toothed belt 4, saddle 5 with seat post, and rear wheel 6 with hub gears and snubber 14 (a belt damper that prevents the toothed belt 4 from jumping off the pulley). Fig. 1 also shows an unsprung frame 7 with movable dropouts. The toothed belt 4 transmits the rider's torque from the crankset 3 to the rear axle or rear wheel hub. Other designs with a chain as a traction mechanism, suspension of the rear wheel 6, an auxiliary drive in the area of ​​the crankset 3 or as part of the front wheel, as well as other bicycle types are possible.

[0102] The brake lines, Bowden cables, or electrical lines used to transmit signals or power to the brakes or gearshift are not shown. Likewise, the control element for controlling the transmission on the handlebar 1 is not shown. This element transmits the driver's shift commands to a shift box or shift actuator for controlling the transmission, either mechanically implemented as a twist grip or push button with Bowden cables, or via a digital interface, electrically via cables or wirelessly (e.g., via radio).

[0103] Furthermore, two section planes AA and BB are defined in Fig. 1. Fig. 2 shows a section through the bicycle in plane AA from the front, and Fig. 3 shows a section through the rear wheel axle in the area of ​​the rear wheel hub in plane BB from the front.

[0104] Fig. 2 shows the dropouts that can be moved in the frame 7, namely the right dropout with the derailleur hanger 8 and the left dropout with the torque arm 9. The spokes 10, the rim 11, the casing 12, the belt pinion 15 and the rear stays 13 of the frame 7 are also shown in section AA. The moveability of the dropouts serves to tension the toothed belt 4 or the chain. The so-called snubber 14 prevents the belt 4 from jumping off the belt pinion 15 in extreme riding situations. The casing 12, together with the rim 11, the spokes 10, the hub shell 16 and possibly a hose (not shown), forms a unit that transfers the output torque of the transmission to the road surface. In addition, the brake disc 17 is mounted on the hub shell 16 so that the speed of the bicycle can be reduced with the help of the brake caliper 18.The thru axle 19 establishes a force-locking and positive connection to the frame by clamping the dropouts to the main axle 21 (see Fig. 3) of the hub gear. This exemplary embodiment also shows an electric shift actuator 20, which transmits the rider's shifting commands to the shift drum 22 (see Fig. 3). A mechanical transmission (e.g., using Bowden cables) is also conceivable.

[0105] Fig. 3 shows a schematic sectional view through the rear wheel axle in section B-B from Fig. 1 in the area of ​​the rear wheel hub, which in this embodiment is a 3-speed hub. The rider's torque is guided via a traction drive to the belt pinion 15 of the gear hub 6, converted by a planetary stage and transmitted to the hub shell 16, which is connected to the driver 29 of the gear. The input shaft of the gear is formed by the driver 25. The spokes 10 attached to the hub shell 16 are not shown and connect the gear to the rim 11, which transmits the torque to the road surface by means of the casing 12. The driver 25 is mounted on the main axle 21 via a ball bearing 24. The main axle 21 is fixed in the frame 7 via a thru axle 19.The sun gear 37 of the planetary gear is permanently connected to the main axle 21 in a rotationally fixed manner and secured against axial displacement by two retaining rings 47. The main axle 21 can transmit a reaction torque generated within the sun gear 37 to the frame 7 via the torque arm 9 (see Fig. 2). The left and right dropouts (not shown in Fig. 3) form the connection to the frame 7.

[0106] In this exemplary embodiment, four axially controlled clutches K1, K2, K3, K4, implemented as claw clutches, are used to realize three gear stages. These clutches K1, K2, K3, K4 are actuated by the shift drum 22. This is a cylindrical body in which spiral grooves are embossed as depressions. The shift drum 22 is rotatably mounted on the main axis 21, whereby the angular position of the shift drum 22 in relation to the main axis 21 defines the states of the individual clutches (active, inactive) for the three gears. This angular position of the shift drum 22 can be indirectly controlled by the rider, here electrically via a shift actuator 20 with an electric motor 43 and via other components not shown here, from the handlebar 1 of the bicycle. The driver 25 has an external toothing 26 and an internal toothing 27.An axially displaceable clutch body 28 is seated on the external toothing 26. It forms a component of clutch K1. This clutch body 28 is constantly pressed against the axially fixed clutch body 31 of clutch K1 by a spring 30. The movable clutch body 28 can be actuated by a shift finger 32. The shift finger 32 penetrates an elongated hole located in the main axis 21. In a preferred embodiment, several shift fingers 32 can be arranged around the circumference. The shift fingers 32 are located at their radially inner end within a groove in the shift drum 22. The shift fingers 32 can displace a shift ring 33 located within the driver 25 in the axial direction. The shift ring 33 can be moved by an axial movement of the shift ring 33.

[0107] If the force-transmitting surfaces of the clutch bodies 28, 31 are designed such that, above a certain torque applied to the driver 25, a diverging movement occurs between the axially displaceable clutch body 28 and the axially fixed clutch body 31, this relative movement must be prevented in driving situations where high torques are to be transmitted. The pressure surfaces of the clutch K1 are the force-transmitting surfaces of the clutch bodies 28, 31. If the pressure surfaces of the clutches K1, K2, K3, K4 are arranged tilted at an average angle of between 92 and 97 degrees to the flat surface, as in this exemplary embodiment, the clutch is self-opening above a certain threshold torque (see also Figs. 8 and 9). This circumstance is intentional, as it simplifies shifting under load.The sliding ring 36 can be moved to the left, allowing the clutch K1 to open slightly even under applied torque. The sliding ring 36 is moved via the shift finger 32 in the groove of the shift drum 22.

[0108] If we look at clutch K1, when engaged, the two halves of the face gearing are held together by a spring 30. To disengage this clutch K1, the spring-loaded, axially movable clutch half 28 is moved axially by means of the sliding ring 36, which is connected to the shift drum 22 via a shift finger 32, so that clutch K1 is disengaged. However, this is only possible if the shift drum 22 has previously opened the latch 34. The latch 34 is constructed similarly to the sliding ring 36. All sliding rings and latches can move axially and are supported torsional to the main axis 21 via a spline. To ensure that clutch K1 is locked and high torques do not cause clutch K1 to disengage, Fig. 3 shows latch 34 in a closed position. The latch 34 and the sliding ring 36 lie completely against the shift ring 33. Clutch K1 is locked.Spring 30 cannot be compressed. Clutch K1 cannot function as a freewheel in this situation.

[0109] The torque is transmitted from the driver 25 via the clutch K1 to the ring gear 38. The axially fixed clutch body 31 of the clutch K1, the axially fixed clutch body 58 of the clutch K2 and the ring gear 38 of the planetary gear form a one-piece component. This component is not axially movable. However, it can rotate freely because it is mounted on the driver 25 and the output member 29. The ring gear 38 is in meshing connection with the large diameter of a stepped planet gear 39. The stepped planet gear 39 is also in meshing connection with the sun gear 37 with its small diameter. The stepped planet gear 39 is mounted on the planet gear axle 42. The planet gear axle 42 is supported on the web 40. Since there are more than three planetary gears on the circumference of the web 40 and they run on the sun gear 37 and the ring gear 38, no radial bearing of the web 40 is necessary.Axially, the web 40 is supported to the left on the driver 25 and to the right on the driver 29. The radially inner regions of the web 40 form the axially fixed coupling body 41 of the coupling K3 on the left and the axially fixed coupling body 44 of the coupling K4 on the right.

[0110] The functions of the four clutches K1, K2, K3 and K4 can be summarized as follows in Fig. 3: a) Clutch K4: The axially movable clutch body 50 operates as a freewheel with the help of the spring 30", which presses it towards the axially fixed clutch body 44, when the latch 52 is in the open position, engaged to the right, and the sliding ring 51, due to its axial position pushed to the left, allows the engagement of the clutch K4. The clutch K4 is deactivated and can rotate freely in both directions of rotation when the latch 52 is in the open position, engaged to the right, and the sliding ring 51, due to its axial position pushed to the right, prevents the engagement of the clutch K4. The clutch K4 is activated and locked when the latch 52 is engaged to the left and the sliding ring 51 is engaged to the left.This prevents the clutch bodies 44 and 50 from moving apart from one another when high applied torques are applied. The latch 52 rests directly on the axially movable clutch body 50. In Fig. 3, the clutch K4 is shown activated and locked. b) Clutch K3: The axially movable clutch body 49 operates as a freewheel with the aid of the spring 30'", which presses it towards the axially fixed clutch body 41, when the latch 45 is in the open position, engaged to the left, and the sliding ring 46, due to its axial position shifted to the right, allows the clutch K3 to be engaged. The clutch K3 is deactivated and can rotate freely in both directions of rotation when the latch 45 is in the open position, engaged to the left, and the sliding ring 46, due to its axial position shifted to the left, prevents the clutch K3 from being engaged.The clutch K3 is activated and locked when the latch 45 is engaged to the right and the sliding ring 46 is engaged to the right. This prevents the clutch bodies 49 and 41 from moving apart from one another under high applied torques. The latch 45 then rests directly on the axially displaceable clutch body 49. In Fig. 3, the clutch K3 is shown deactivated. c) Clutch K1: The axially displaceable clutch body 28 operates as a freewheel with the aid of the spring 30, which presses it towards the axially fixed clutch body 31, when the latch 34 is engaged to the left in the open position and the sliding ring 36, due to its axial position shifted to the right, allows the clutch K1 to be engaged.The clutch K1 is deactivated and can rotate freely in both directions when the latch 34 is in the open position, engaged to the left, and the sliding ring 36, due to its axial position engaged to the left, prevents the clutch K1 from engaging. The clutch K1 is activated and locked when the latch 34 is engaged to the right and the sliding ring 36 is engaged to the right. This prevents the clutch bodies 28 and 31 from moving apart from one another under high applied torques. The latch 34 then rests directly on the switching ring 33. The switching ring 33 then rests on the axially displaceable clutch body 28 via the locking finger 35. In Fig. 3, the clutch K1 is shown activated and locked.d) Clutch K2: The axially movable clutch body 57 operates as a freewheel with the aid of the spring 30', which presses it towards the axially fixed clutch body 58, when the latch 53 is in the open position, engaged to the right, and the sliding ring 56, due to its axial position shifted to the left, allows the clutch K2 to be engaged. The clutch K2 is deactivated and can rotate freely in both directions of rotation when the latch 53 is in the open position, engaged to the right, and the sliding ring 56, due to its axial position shifted to the right, prevents the clutch K2 from being engaged. The clutch K2 is activated and locked when the latch 53 is engaged to the left and the sliding ring 56 is engaged to the left. A separation of the clutch bodies 57 and 58 relative to one another at high applied torques is thus prevented. The latch 53 then rests directly on the switching ring 54.The switching ring 54 then rests on the axially displaceable coupling body 57 via the locking finger 35". In Fig. 3, the coupling K1 is shown deactivated.

[0111] The guide pin 55 is firmly pressed into the main axis 21 and its end runs in a groove located within the shift drum 22. In this way, the axial position of the shift drum 22 remains constant during its rotational movement. Since the shift drum 22 has helical grooves (not shown) in which the locking fingers 35, 35', 35", 35'" and the shift fingers 32, 32', 32", 32'" slide without play, the axial position of all locks 34, 45, 52, 53 and all sliding rings 36, 46, 51, 56 can be precisely controlled by rotating the shift drum 22. In an advantageous embodiment, the friction on the surfaces of the sliding rings 36, 46, 51, 56 and latches 34, 45, 52, 53, where they are connected to the switching rings 33, 54 or the coupling bodies 49, 50, is minimized by bearings.

[0112] The ring gear 38 has 113 teeth. The stepped planetary gear 39 has 35 teeth on its large diameter and 20 teeth on its small diameter. The sun gear 37 has 58 teeth. The following table shows the different gear ratios depending on the condition of each individual clutch K1, K2, K3, and K4. The following table shows, with the help of arrows pointing to the right or left, the position in which the respective latch 34, 45, 52, 53 or sliding ring 36, 46, 51, 56 must be in the engaged gear or during the shifting process between the gears. In Fig. 3, each clutch K1, K2, K3, K4 has a latch 34, 45, 52, 53 and a sliding ring 36, 46, 51, 56, which is referred to as a ring in the table. The arrow pointing to the right or left indicates the position in which the respective latch 34, 45, 52, 53 or sliding ring 36, 46, 51, 56 must be. It can be seen that between the gears, the clutch K1, K2, K3, K4 which is to change state must first be unlocked. After unlocking, each clutch K1, K2, K3, K4 can work as a freewheel if the sliding ring 36, 46, 51, 56 is in an activated position.This is important so that on the one hand, neutral is not possible between gears and on the other hand, the transmission cannot jam.

[0113] Another table with the same structure below also shows the condition of the respective latch 34, 45, 52, 53 and sliding ring 36, 46, 51, 56.

[0114] As soon as a bolt 34, 45, 52, 53 is “locked”, the

[0115] Clutch teeth do not work as a freewheel, and even high

[0116] Torques can be transmitted.

[0117] As soon as a bolt 34, 45, 52, 53 is “unlocked”, the

[0118] Clutch teeth work as a freewheel, and the force-transmitting surfaces on the clutch teeth can be easily moved towards each other and opened even under load.

[0119] As soon as a sliding ring 36, 46, 51, 56 is "pulled," the force-transmitting surfaces on the clutch teeth cannot engage with each other. The clutch is deactivated and can rotate freely in both directions.

[0120] As soon as a sliding ring 36, 46, 51, 56 is "open," the force-transmitting surfaces on the clutch teeth can engage with each other. The clutch is activated. The axially movable clutch body 28, 57, 49, 50 is pressed against the axially fixed clutch body 31, 41, 44, 58 by the spring.

[0121] Fig. 4 shows a third embodiment KE4 of a coupling device according to the invention in the open state (Fig. 4a), in an intermediate state (Fig. 4b), and in the closed state (Fig. 4c). The operation of the coupling device KE4 is explained using the open state (Fig. 4a). Since Figs. 4b and 4c show the same coupling device KE4 as Fig. 4a, only in different states, they have not been provided with reference numerals.

[0122] In this embodiment, the clutch device KE4 is used to transmit torque from a hub 401 to a shaft 400. The hub 401 is designed as a gear, which is driven by another gear 404. The torque flow from the driving gear 404 via the hub 401, which is designed as a gear, to the shaft 400 is schematically indicated by arrows.

[0123] The hub 401 is freely rotatably mounted on the shaft 400 via a hub bearing 413 and secured against axial displacement by retaining rings 414, 415. A fixed coupling half 402 is integrally connected to the hub 401 and carries a spur gear 405 in the axial direction. Axially opposite the fixed coupling half 402, a movable coupling half 403, also designed as a hub, is arranged on the shaft 400. The movable coupling half 403 is connected to the shaft 400 in a rotationally fixed manner, thus transmitting torque, and simultaneously axially displaceable, via an internal gear 411 that engages with an external gear 412 of the shaft 400. The movable coupling half 403 carries a spur gear 406, which can engage with the spur gear 405 of the fixed coupling half 402. The movable coupling half 403 thus forms a claw coupling together with the fixed coupling half 402.

[0124] The movable clutch half 403 is actuated by a clutch actuation 408. Since the clutch actuation 408 does not rotate on the shaft 400, a clutch actuation bearing 407 is arranged axially between the clutch actuation 408 and the movable clutch half 403, which transmits the axial actuation force of the stationary clutch actuation 408 to the rotating movable clutch half 403. The clutch actuation bearing 407 is preferably designed as a roller bearing.

[0125] An actuator 410 is provided to control the clutch actuation 408. A first spring 409 is arranged axially between the clutch actuation 408 and the actuator 410. This spring is designed as a compression spring and can be preloaded by an axial displacement of the actuator 410.

[0126] The drive for the axial displacement of the actuator 410 is provided by an electric motor 419. This drives a reduction gear 421 via a motor pinion 420 to reduce the motor speed. The reduction gear 421 drives a spindle 422, the external thread of which engages with an internal thread 418 of the actuator 410.

[0127] The spindle drive allows the actuator 410 to be axially displaced. This initially preloads the first spring 409, which in turn presses the movable coupling half 403 against the fixed coupling half 402 via the clutch actuation 408 and the clutch actuation bearing 407. The strength of the contact force, which thus acts in the closing direction of the claw clutch, depends on the degree of preload of the first spring 409. The range of axial displaceability of the movable coupling half 403 on the shaft 400 is limited by two retaining rings 416, 417. A second spring 423, which is also designed as a compression spring, is arranged axially between the retaining ring 416 facing the fixed coupling half 402 and the movable coupling half 403. The second spring 423 is always pre-tensioned and exerts a force on the movable coupling half 403 which acts in the opening direction of the claw coupling.

[0128] In the illustration in Fig. 4a, the actuator 410 has been moved axially far to the right by the spindle drive, so that the first spring 409 is completely released. As a result, the second spring 423 pushes the movable coupling half 403 to the right until it strikes the retaining ring 417. The two spur gears 405 and 406 on the fixed coupling half 402 and the movable coupling half 403, respectively, are therefore completely disengaged, and the coupling device KE4 is in the open state.

[0129] In the illustration in Fig. 4b, the actuator 410 has been moved axially further to the left compared to the illustration in Fig. 4a, so that the first spring 409 is partially preloaded and its spring force exceeds the spring force of the second spring 423. The two spur gear teeth 405 and 406 are thus engaged. The clutch device KE4 is in an intermediate state.

[0130] However, the engagement between the two spur gears 405 and 406 is only so strong that this engagement can be released by a sufficiently large operating torque, which is applied to the hub 401 via the driving gear 404. If the clutch device KE4 is to be opened from the intermediate state, this opening is thus assisted by the operating torque. For this purpose, the spur gears 405 and 406 have drive surfaces inclined relative to a radial plane, which can slide off one another, causing the movable coupling half 403 to move axially to the right away from the fixed coupling half 402 and thus releasing the engagement between the two spur gears 405 and 406. This will be described in more detail in connection with Figs. 8 and 9.

[0131] If the clutch device KE4 is to be closed from the intermediate state, the actuator 410 is moved axially further to the left. In the illustration in Fig. 4c, the actuator 410 has been moved axially as far as possible to the left, so that it strikes the clutch actuation 408. The first spring 409 is maximally preloaded and preferably even goes into a block. The spur gears 405 and 406 are firmly engaged with each other, which cannot be released even by a high operating torque. The clutch device KE4 is thus in the closed state.

[0132] Because the actuator 410 can abut against the clutch actuation 408, the mobility of the movable clutch half 403 in the axial direction away from the fixed clutch half 402 is limited, so that the actuator 410 acts as a movable limiting device. This is particularly evident when the clutch device KE4 is closed, in which the actuator 410 abuts against the clutch actuation 408 and thus locks the clutch device KE4. In the axial direction toward the fixed clutch half 402, however, the mobility of the movable clutch half 403 is limited by the fixed clutch half 402 itself, in that the two clutch halves 402, 403 abut against each other at the maximum penetration depth of the two spur gear teeth 405, 406.

[0133] Figs. 5 to 7 show further embodiments KE5, KE6, KE7 of the coupling device according to the invention. Therefore, reference numerals corresponding to those in Fig. 4 were used wherever possible, with the first digit of a reference numeral always indicating the number of the respective figure. Since the basic structure of the coupling devices KE5, KE6, KE7 according to Figs. 5 to 7 corresponds to that of the coupling device KE4 according to Fig. 4, only the respective differences will be discussed below.

[0134] Fig. 5 shows a fourth embodiment KE5 of a coupling device according to the invention. Here, the spring force of the first spring 509 does not act in the closing direction of the coupling device KE5, but in the opposite direction. The spring force is therefore redirected in the closing direction of the coupling device KE5 by a lever 524, which is mounted at a fixed point and acts in the form of a rocker with, in this embodiment, lever arms of equal length. However, the lever 524 can also have lever arms of different lengths, resulting in an increase or decrease in the spring force. In order to reduce the friction between the end points of the two lever arms of the lever 524 and the adjacent component, the first spring 509 is accommodated in a spring housing 526 with mutually displaceable halves and rounded ends, which establishes contact at one end of the first spring 509 with the end point of one lever arm of the lever 524.Secondly, for this purpose, a lever bearing 525 in the form of a roller bearing is arranged between the clutch actuation 508 and the end point of the other lever arm of the lever 524. Furthermore, the two halves of the spring housing 526 can strike each other at maximum preload of the first spring 509 and thereby, particularly in the closed state of the clutch device KE5, limit the mobility of the movable clutch half 503 in the axial direction away from the fixed clutch half 502, so that the spring housing 526 acts as a movable limiting device.

[0135] Furthermore, the actuator 510 does not press against the first spring 509 in the axial direction in order to preload it, but via a wedge gear consisting of the wedge surfaces 527, 528 on the actuator 510 or on the end of the spring housing 526 opposite the lever 524. This results in a reduction of the travel of the spring housing 526 and thus of the first spring 509 compared to the travel of the actuator 510, whereby the force applied to preload the first spring 509 is increased accordingly.

[0136] Fig. 6 shows a fifth embodiment KE6 of a clutch device according to the invention. Two such clutch devices KE6 are shown, each of which selectively connects a hub 601, designed as a gear, to a common shaft 600 in a torque-transmitting manner. The clutch device KE6 on the left in Fig. 6 is in the open state, and the right one is in the closed state.

[0137] In this case, the first spring 609 is not arranged parallel to the shaft 600, but orthogonally to it. The spring force of the first spring 609 is deflected by 90 degrees via a wedge mechanism consisting of the wedge surfaces 627, 628 on the movable clutch half 603 and on the clutch actuation 608, respectively, in order to generate the actuation force acting in the closing direction of the clutch device KE6. The wedge surface 627 on the movable clutch half 603 is arranged circumferentially and has the shape of a truncated cone. The wedge mechanism with the wedge surfaces 627, 628 thus simultaneously serves as a plain bearing, through which the movement of the stationary clutch actuation 608 is transmitted to the rotating, movable clutch half 603. A separate clutch actuation bearing as in the previous embodiments is therefore unnecessary in this case.

[0138] In Fig. 6, the actuator 610 is not controlled via a spindle drive, as in the previous embodiments, but via the camshaft 629. Depending on the rotational position of the camshaft 629, the actuator 610 is displaced by different distances via an eccentric cam 630 that is non-rotatably connected to the camshaft, thereby causing a different preload of the first spring 609. Similar to the spindle in the previous embodiments, the camshaft 629 is driven by an electric motor 619, a motor pinion 620, and a reduction gear 621.

[0139] Such a cam control allows different states of multiple clutch devices KE6 to be achieved at the same time in a simple and precisely synchronized manner via a common camshaft 629 by means of multiple cams 630 arranged differently with respect to their rotational position. Fig. 6 shows two clutch devices KE6 as examples, which are in the aforementioned states. The cam control is therefore particularly suitable for a spur gear transmission in which a plurality of idler gears 601 must be selectively and synchronously connected to an idler gear shaft 600 by a plurality of clutch devices KE6 in a torque-transmitting manner.

[0140] The actuator 610 and the clutch actuation 608 can also strike one another when the first spring 609 is at maximum preload and thereby, particularly when the clutch device KE6 is in the closed state, limit the mobility of the movable clutch half 603 in the axial direction away from the fixed clutch half 602, so that the actuator 610 acts as a movable limiting device. Fig. 7 shows a sixth embodiment KE7 of a clutch device according to the invention. Two of these clutch devices KE7 are again shown, each of which selectively connects a hub 701 designed as a gear to a common shaft 700 in a torque-transmitting manner. The upper clutch device KE7 in Fig. 7 is in the open state and the lower one is in the closed state.

[0141] In Fig. 7, the spring force of the first spring 709 is deflected by at least one guide rail, thereby generating the actuating force for the movable coupling half 703. An actuator 710, which, similar to Fig. 6, can be displaced by a camshaft 729 with an eccentric cam 730, presses against one end of the first spring 709 to preload it. The other end of the first spring 709 displaces a guide rail push rod 733, which has an S-shaped guide rail opening 732. A guide rail bearing 736 arranged in the guide rail opening 732 follows the displacement of the guide rail opening 732 and in this way pivots a guide rail follower 731, to one outer end of which the guide rail bearing 736 is attached. At its other outer end, the guide rail follower 731 is rotatably mounted about a fixed point by a pivot bearing 735. In the embodiment according to Fig.7, two such guide rails are arranged offset by 180 degrees on the circumference of the coupling device KE7.

[0142] The link guide is designed such that, due to the displacement of the link push rod 733 and the resulting pivoting of the link follower 731, a pressure peak 734 of the link follower 731 presses in the direction of the clutch actuation 708. Similar to what was already described for Figs. 4 and 5, the clutch actuation 708 presses via a clutch actuation bearing 707 onto the rotating, movable coupling half 703 in order to engage its spur gearing 706 with a spur gearing 705 on the hub 701. Since the spur gearing 705 is arranged directly on the hub 701, no separate, fixed coupling half is formed in this case. Furthermore, the link bearing 736 can be accommodated in the end region of the link opening 732 during a maximum deflection of the link push rod 733 and can therefore no longer be movable in the axial direction.The mobility of the movable coupling half 703 in the axial direction away from the hub 701 is thereby limited by the link follower 731, so that the link guide acts as a movable limiting device in the closed state of the coupling device KE7.

[0143] The function of the second spring, which is intended to ensure complete opening of the coupling device KE7 when the preload of the first spring 709 is removed, is in this case divided into three individual second springs 723a-c, which act on the link follower 731, on the movable coupling half 703 or on the link push rod 733 in order to return the respective component against the actuating force caused by the first spring 709.

[0144] Fig. 8 shows once again the movable coupling half 403 from Fig. 4 in a perspective side view to illustrate the spur gearing 406 of the movable coupling half 403, which engages with the (in this respect identically designed) spur gearing 405 of the fixed coupling half 402.

[0145] Fig. 9 shows a radially external section of the spur gearing 406, in which one of the teeth 900 is shown in detail. It can be seen that the drive surface 901 of the tooth 900, which is directed forward in a first direction of rotation (the drive direction in which the clutch device KE4 is intended to transmit torque), does not extend exactly in an (imaginary) radial plane containing the axis of rotation of the movable clutch half 403, but is inclined by an angle α relative to this radial plane. This angle α is preferably between 4 and 10 degrees and, in the exemplary embodiment according to Fig. 9, approximately 5 degrees.

[0146] When the clutch device is in the closed state or in an intermediate state, the drive surface 901 comes into contact with a correspondingly inclined drive surface on a tooth of the spur gearing 406 of the fixed clutch half 402. Due to the inclination of the two drive surfaces, they can slide against each other when the movable clutch half 403 is subjected to an operating torque, causing the clutch device to open. This is counteracted by the frictional force between the two drive surfaces and the actuating force generated by the first spring 409, which acts in the closing direction of the clutch device KE4. As soon as the operating torque exceeds a certain threshold torque, the aforementioned forces are overcome, and the two drive surfaces slide against each other, causing the clutch device KE4 to open.

[0147] If the clutch mechanism is part of a bicycle's transmission, this process can, as already mentioned, assist the opening of the clutch mechanism through the operating torque applied by the cyclist. Conversely, only a relatively low actuation force is required by the actuating device, for example, a gear lever or electric motor. Furthermore, shifting under load is easier this way, since the operating torque itself can be used to initiate the opening process of the clutch mechanism and thus the shifting process.

[0148] In the second direction, opposite to the first direction of rotation, a freewheeling surface 902 of tooth 900 on the movable coupling half 403 comes into contact with a corresponding freewheeling surface on the fixed coupling half 402. The inclination of the freewheeling surface 902 is significantly greater than the angle α; in the embodiment according to Fig. 9, it is approximately 45 degrees. This results in a "sawtooth-like" profile of the spur gear teeth 406. Therefore, the two freewheeling surfaces slide against each other much more easily in the second direction of rotation than the two drive surfaces in the first direction of rotation. In this way, a freewheeling function is always realized in the second direction of rotation in the intermediate state, so that in the intermediate state in the second direction of rotation, practically no torque can be transmitted via the clutch device KE4.The selective torque transmission from the first to the second clutch half therefore essentially only acts in the first direction of rotation.

[0149] Reference symbol list

[0150] 1 handlebar with stem, 28 axially adjustable brake levers and grips clutch body K1

[0151] 2 suspension fork with front wheel 29 Abtreiber

[0152] 3 Crank group with pedals 30-30“' spring and belt wheel 40 31 Axial fixed

[0153] 4 timing belt clutch body K1

[0154] 5 Saddle with seat post 32-32" shift finger

[0155] 6 rear wheel with 33 shift ring

[0156] Hub gear 34 bar K1

[0157] 7 frames 45 35-35'““ locking fingers

[0158] 8 derailleur hanger 36 sliding ring K1

[0159] 9 Torque support 37 Sun gear

[0160] 10 spokes 38 ring gear

[0161] 11 Rim 39 Stepped planetary gear

[0162] 12 Sheath 50 40 Bridge

[0163] 13 Rear stays 41 Axial fixed

[0164] 14 Snubber coupling body K3

[0165] 15 Belt pinion 42 Planetary gear axle

[0166] 16 Hub shell 43 Electric motor

[0167] 17 Brake disc 55 44 Axially fixed

[0168] 18 Brake caliper clutch body K4

[0169] 19 Quick release axle 45 Lock K3

[0170] 20 Shift actuator 46 Sliding ring K3

[0171] 21 Main axis 47 Retaining ring, spring ring

[0172] 22 Shift drum 60 48 Spline

[0173] 23 Driver 49 Axially movable

[0174] 24 ball bearing clutch body K3

[0175] 25 Driver 50 Axially movable

[0176] 26 External teeth of coupling body K4

[0177] 27 Internal toothing 65 51 Sliding ring K4

[0178] 52 bars K4

[0179] K1-K4 claw coupling 53 latch K2

[0180] 54 Switching ring K2 55 Guide pin 503 Movable

[0181] 56 Sliding ring K2 coupling half

[0182] 57 Axially movable 504 Driving gear clutch body K2 505, 506 Spur gearing

[0183] 58 Axially fixed 40 507 clutch actuation clutch body K2 bearing

[0184] 508 clutch actuation

[0185] KE4 clutch device 509 first spring

[0186] 400 Shaft 510 Actuator

[0187] 401 Hub 45 511 Internal gearing

[0188] 402 Fixed coupling half 512 External gearing

[0189] 403 Movable 513 Hub bearing clutch half 514-517 Retaining ring

[0190] 404 Driving gear 518 Internal thread

[0191] 405, 406 Spur gearing 50 519 Electric motor

[0192] 407 Clutch actuation 520 Engine pinion bearing 521 Reduction gear

[0193] 408 Clutch actuation 522 Spindle

[0194] 409 First spring 523 Second spring

[0195] 410 Actuator 55 524 Lever

[0196] 411 Internal gearing 525 Lever bearing

[0197] 412 External gearing 526 Spring housing

[0198] 413 Hub bearing 527, 528 Wedge surface 414-417 Retaining ring

[0199] 418 internal thread 60 KE6 coupling device

[0200] 419 Electric motor 600 Shaft

[0201] 420 Motor pinion 601 Hub

[0202] 421 Reduction gear 602 Fixed coupling half

[0203] 422 Spindle 603 Movable

[0204] 423 Second spring 65 clutch half

[0205] 605, 606 spur gearing

[0206] KE5 clutch device 607 clutch actuation

[0207] 500 shaft bearings

[0208] 501 Hub 608 Clutch actuation

[0209] 502 Fixed coupling half 70 609 First spring 610 Actuator 735 Pivot bearing of the

[0210] 611 Internal gearing of the link follower

[0211] 612 External gearing 736 Link bearing of the

[0212] 614-617 Retaining ring for link follower

[0213] 619 electric motor 40

[0214] 620 Motor pinion QQQ tooth of

[0215] 621 Reduction gear spur gearing

[0216] 623 Second spring Drive surface

[0217] 627, 628 wedge surface gg2 Free-running area

[0218] 629 camshaft

[0219] 45

[0220] 630 cam

[0221] KE7 coupling device

[0222] 700 wave

[0223] 701 hub

[0224] 703 Movable coupling half

[0225] 704 Driving gear

[0226] 705, 706 spur gearing

[0227] 707 clutch actuation bearing

[0228] 708 clutch actuation

[0229] 709 First Spring

[0230] 710 Actuator

[0231] 711 internal gearing

[0232] 712 external gearing

[0233] 714-715 Retaining ring

[0234] 723a-c Second spring

[0235] 729 camshaft

[0236] 730 cam

[0237] 731 Scenery Follower

[0238] 732 backdrop opening

[0239] 733 Link rod

[0240] 734 Pressure peak of the link follower

Claims

Patent claims 1. Coupling device (K1-K4, KE4-KE7) for the selective transmission of a torque from a first shaft or hub (25, 38, 40, 401, 501, 601, 701) to a second shaft or hub (29, 38, 40, 400, 500, 600, 700), in particular for a gearshift for a bicycle, comprising a first coupling half (28, 44, 49, 58, 402, 502, 602, 701), which is connected in a rotationally fixed manner to the first shaft or hub (25, 38, 40, 401, 501, 601, 701), a second coupling half (31, 41, 50, 57, 403, 503, 603, 703), which is connected to the second shaft or hub (29, 38, 40, 400, 500, 600, 700) in a rotationally fixed manner, and an actuating device (20; 410, 418-422; 510, 518-522; 610, 619-621, 629, 630; 710, 729, 730), characterized in that the coupling device (K1-K4, KE4-KE7) is actuated by actuating the actuating device (20; 410, 418-422; 510, 518-522; 610, 619-621, 629, 630; 710, 729, 730) - into a closed state in which a torque can be transmitted from the first coupling half (28, 44, 49, 58, 402, 502, 602) to the second coupling half (31, 41, 50, 57, 403, 503, 603, 703) in both directions of rotation and in which, in particular, the first coupling half (28, 44, 49, 58, 402, 502, 602) is connected to the second coupling half (31, 41, 50, 57, 403, 503, 603, 703) in a rotationally fixed manner, - in at least one intermediate state in which, in a first direction of rotation, a torque which is less than or equal to a threshold torque dependent on the intermediate state and no torque which is greater than the threshold torque of the intermediate state, and in a second direction of rotation opposite to the first direction of rotation, essentially no torque can be transmitted from the first coupling half (28, 44, 49, 58, 402, 502, 602) to the second coupling half (31, 41, 50, 57, 403, 503, 603, 703), and - into an open state in which no torque can be transmitted from the first coupling half (28, 44, 49, 58, 402, 502, 602) to the second coupling half (31, 41, 50, 57, 403, 503, 603, 703) in any direction of rotation, can be brought.

2. Clutch device (K1-K4, KE4-KE7) according to claim 1, characterized in that the clutch device (K1-K4, KE4-KE7) can be brought into a plurality of intermediate states with different threshold torques by actuating the actuating device (20; 410, 418-422; 510, 518-522; 610, 619-621, 629, 630; 710, 729, 730).

3. Clutch device according to claim 2, characterized in that the clutch device (K1-K4, KE4-KE7) can be brought by the actuation of the actuating device (20; 410, 418-422; 510, 518-522; 610, 619-621, 629, 630; 710, 729, 730) starting from the closed state successively, in particular continuously, into the plurality of intermediate states and finally into the open state, wherein the threshold torques of the intermediate states decrease monotonically, and can be brought in the reverse order starting from the open state into the closed state.

4. Coupling device (K1-K4, KE4-KE7) according to one of the preceding claims, characterized in that the first coupling half (28, 44, 49, 58, 402, 502, 602) and the second coupling half (31, 41, 50, 57, 403, 503, 603, 703) are movable relative to one another and are designed to produce a separable, positive connection with one another, in particular by means of claws (405, 406; 505, 506; 605, 606; 705, 706) on the first coupling half (28, 44, 49, 58, 402, 502, 602) and on the second coupling half (31, 41, 50, 57, 403, 503, 603, 703), whereby the positive connection - in the closed state of the coupling device (K1-K4, KE4-KE7), - in the at least one intermediate state of the coupling device (K1-K4, KE4-KE7) when the first coupling half (28, 44, 49, 58, 402, 502, 602) is acted upon in the first direction of rotation with a Torque which is less than or equal to the threshold torque of the at least one intermediate state, and is separable by applying a torque to the first clutch half (28, 44, 49, 58, 402, 502, 602) in the first direction of rotation which is greater than the threshold torque of the at least one intermediate state, and - in the open state of the coupling device (K1-K4, KE4-KE7) is separated.

5. Coupling device (K1-K4, KE4-KE7) according to claim 4, characterized in that the coupling device (K1-K4, KE4-KE7) is designed to be movable by a respective different restriction of the possible positions of a movable coupling half (28, 49, 50, 57, 403, 503, 603, 703), which is one of the first coupling half (28, 44, 49, 58, 403, 503, 603, 703) and the second coupling half (31, 41, 50, 57, 402, 502, 602, 701), to a specific position or a specific range of positions relative to the other coupling half (31, 41, 44, 58, 402, 502, 602, 701) by the Actuating device (20; 410, 418-422; 510, 518-522; 610, 619-621, 629, 630; 710, 729, 730) can be brought into the open state, into at least one intermediate state and / or into the closed state.

6. Coupling device (K1-K4, KE4-KE7) according to claim 5, characterized in that the coupling device (K1-K4, KE4-KE7) can be brought into the open state by restricting the possible positions of the movable coupling half (28, 49, 50, 57, 403, 503, 603, 703) to a position in which the positive connection is separated, can be brought into the at least one intermediate state by restricting the possible positions of the movable coupling half (28, 49, 50, 57, 403, 503, 603, 703) to a range between a position in which the positive connection is established and a position in which the positive connection is separated, and / or can be brought into the closed state by restricting the possible positions of the movable coupling half (28, 49, 50, 57, 403, 503, 603, 703) can be restricted to a position in which the positive connection is established.

7. Coupling device (K1-K4, KE4-KE7) according to claim 6, characterized in that the coupling device (K1-K4) has one or two movable limiting devices (34, 36; 53, 56; 45, 46; 51, 52; 410; 526; 610; 731-736), wherein the range of possible positions of the movable coupling half (28, 49, 50, 57, 403, 503, 603, 703) is defined by the area between one limiting device (410; 526; 610; 731-736) and the other coupling half (402, 502, 602, 701) or by the area between the two limiting devices (34, 36; 53, 56; 45, 46; 51, 52).

8. Coupling device (K1-K4) according to one of claims 5 to 7, characterized in that the coupling device (K1-K4) further comprises a spring (30-30") which is prestressed in the at least one intermediate state, wherein the spring (30-30"), when prestressed, can generate a spring force by which an actuating force acting in the closing direction of the positive connection can be generated directly or indirectly.

9. Coupling device (K1, K2) according to claim 8, characterized in that the spring (30-30") is supported at a first end on the movable coupling half (28, 57) and at a second end opposite the first end on a component (25, 29) which is immovable relative to the other coupling half (31, 41, 44, 58).

10. Coupling device (K3, K4) according to claims 7 and 8, characterized in that the spring is supported at a first end on the movable coupling half (49, 50) and at a second end opposite the first end on a limiting device (45, 52).

11. Coupling device (KE4-KE7) according to claim 4, characterized in that the coupling device (KE4-KE7) has a first spring (409, 509, 609, 709), that the actuating device (410, 418-422; 510, 518-522; 610, 619-621, 629, 630; 710, 729, 730) is designed to preload the first spring (409, 509, 609, 709), that the coupling device (KE4-KE7) can be released by reducing the preload of the first spring (409, 509, 609, 709) by the actuating device (410, 418-422; 510, 518-522; 610, 619-621, 629, 630; 710, 729, 730) can be brought into the open state, that the clutch device (KE4-KE7) by increasing the preload of the first spring (409, 509, 609, 709) by the actuating device (410, 418-422; 510, 518-522; 610, 619-621, 629, 630;710, 729, 730) can be brought into the at least one intermediate state, wherein the degree of preload of the first spring (409, 509, 609, 709) determines the threshold torque of the intermediate state, and that the clutch device (KE4-KE7) can be brought into the closed state by a further increase in the preload of the first spring (409, 509, 609, 709) by the actuating device (410, 418-422; 510, 518-522; 610, 619-621, 629, 630; 710, 729, 730); 12. Coupling device (KE4-KE7) according to claim 11, characterized in that the first spring (409, 509, 609, 709), when pretensioned, can generate a first spring force, by which a first actuating force acting in the closing direction of the positive connection can be generated directly or indirectly.

13. Coupling device (KE4-KE7) according to claim 12, characterized in that the first spring force acts in a direction substantially equal to the closing direction of the positive connection between the first coupling half (28, 44, 49, 58, 402, 502, 602) and the second coupling half (31, 41, 50, 57, 403, 503, 603, 703), in a direction substantially opposite to this closing direction or in a direction substantially orthogonal to this closing direction.

14. Coupling device (KE5-KE7) according to claim 13, characterized in that the first spring force can be deflected by a lever gear (524-525), a wedge gear (627-628) and / or a slotted guide (731-736) in order to generate the first actuating force.

15. Coupling device (KE4-KE7) according to one of claims 11 to 14, characterized in that the coupling device (KE4-KE7) has a second spring (423, 523, 623, 723a-c) which is prestressed in the closed state and in the at least one intermediate state of the coupling device (KE4-KE7), and in that a second actuating force acting in the opening direction of the positive connection can be generated directly or indirectly by the second spring (423, 523, 623, 723a-c), when it is prestressed.

16. Coupling device (KE4-KE7) according to claim 15, characterized in that the first spring (409, 509, 609, 709) has a greater spring constant than the second spring (423, 523, 623, 723a-c).

17. Coupling device (K1-K4, KE4-KE7) according to one of claims 4 to 16, characterized in that the first coupling half (28, 44, 49, 58, 402, 502, 602) has at least one first substantially planar drive surface (901) and the second coupling half (31, 41, 50, 57, 403, 503, 603, 703) has at least one second substantially planar drive surface (901), which can be brought into contact with one another in order to produce the positive connection in the first direction of rotation, wherein the at least one first drive surface (901) and / or the at least one second drive surface (901) are arranged opposite a radial plane through which the axis of rotation of the first coupling half (28, 44, 49, 58, 402, 502, 602) or the second coupling half (31, 41, 50, 57, 403, 503, 603, 703) and which intersects the respective drive surface (901), on one of the second Coupling half (31, 41, 50, 57, 403, 503, 603, 703) facing side against the first direction of rotation and on a side facing away from the second coupling half (31, 41, 50, 57, 403, 503, 603, 703) is inclined in the first direction of rotation, wherein by the at least one first drive surface (901) and / or the at least one second drive surface (901) in the at least one intermediate state, when the first coupling half (28, 44, 49, 58, 402, 502, 602) is subjected in the first direction of rotation to a torque which is greater than the threshold torque of the at least one intermediate state, a separation of the positive connection between the first coupling half (28, 44, 49, 58, 402, 502, 602) and the second coupling half (31, 41, 50, 57, 403, 503, 603, 703) can be effected.

18. Coupling device (K1-K4, KE4-KE7) according to claim 17, characterized in that the inclination angle of the at least one first drive surface (901) and / or of the at least one second drive surface (901) relative to the respective radial plane is 2 to 10 degrees, preferably 4 to 7 degrees, more preferably approximately 5 degrees.

19. Coupling device (K1-K4, KE4-KE7) according to one of claims 4 to 18, characterized in that the first coupling half (28, 44, 49, 58, 402, 502, 602) has at least one first substantially flat running surface (902) and the second coupling half (31, 41, 50, 57, 403, 503, 603, 703) has at least one second substantially flat running surface (902), which can be brought into contact with each other to produce the form-fitting connection in the second rotational direction, the at least one first running surface (902) and / or the at least one second running surface (902) relative to a radial plane through which the axis of rotation of the first coupling half (28, 44, 49, 58, 402, 502, 602) or the second coupling half (31, 41, 50, 57, 403, 503, 603, 703) runs and which intersects the respective freewheel surface (902), on a side facing the second coupling half (31, 41, 50, 57, 403, 503, 603, 703) in the first direction of rotation and on a side facing the second coupling half (31, 41, 50, 57, 403, 503, 603, 703) is inclined against the first direction of rotation, wherein the at least one first freewheel surface (902) and / or the at least one second freewheel surface (902) in the at least one intermediate state when the first coupling half (28, 44, 49, 58, 402, 502, 602) is subjected to a torque in the second direction of rotation, can cause a separation of the positive connection between the first coupling half (28, 44, 49, 58, 402, 502, 602) and the second coupling half (31, 41, 50, 57, 403, 503, 603, 703).

20. Clutch device (K1-K4, KE4-KE7) according to claim 19, characterized in that the angle of inclination of the at least one first freewheel surface (902) and / or the at least one second freewheel surface (902) relative to the respective radial plane is 35 to 75 degrees, preferably 45 to 65 degrees, more preferably approximately 55 degrees.

21. Gearshift for a bicycle with at least one clutch device (K1-K4, KE4-KE7) according to one of the preceding claims.

22. Gearshift according to claim 21 with at least one partial transmission, wherein each partial transmission has an idler gear shaft (600, 700) on which at least one idler gear (601, 701) is mounted, at least one clutch device (KE6, KE7) according to one of claims 1 to 20 and a gear shaft on which at least one gear (704) is mounted in a rotationally fixed manner, wherein the at least one idler gear (601, 701) meshes with the at least one gear (704) and wherein a torque can be selectively transmitted from the at least one idler gear (601, 701) to the idler gear shaft (600, 700) or vice versa by the at least one clutch device (KE6, KE7) in order to put a gear stage of the respective partial transmission into operation.

23. Gearbox according to claim 22 with a first partial transmission and a second partial transmission, which are used to transmit a torque are connected in series from the first sub-gearbox to the second sub-gearbox.

Images