Device and method for changing center of gravity of bicycle according to situation

Abstract

To further enhance safety of a cyclist and provide a device, a system, a bicycle, and a method for changing the center of gravity of the bicycle according to the situation.SOLUTION: The present invention relates to a device (1) configured to change the center of gravity of a bicycle, in particular an electric bicycle, and includes: an actuator (2) configured to change the center of gravity of the bicycle; at least one sensor configured to monitor a riding status of the bicycle; and a control unit configured to receive and process data from the sensor, determine the center of gravity appropriate for the situation, and output a corresponding control signal to the actuator to execute the change of the center of gravity. According to the present invention, the adjustment speed for changing the center of gravity can be adapted to the riding status of the bicycle. The present invention also relates to a system and a bicycle that are adapted to change the center of gravity of the bicycle according to the situation. Furthermore, the present invention relates to a method for changing the center of gravity of a bicycle according to the situation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] statement The present invention relates to a situation-adaptive center of gravity changing device for a bicycle, in particular an electric bicycle, comprising an actuator for changing the center of gravity, at least one sensor for monitoring the riding conditions of the bicycle, and a control unit for receiving and processing data from the sensor, determining a situation-adaptive center of gravity of the bicycle, and outputting corresponding control signals to the actuator for performing the change of the center of gravity.

[0002] The increasing demand in road traffic has led to an increasing need for safety measures, especially for cyclists. Due to the high center of gravity of the bicycle, which is further aggravated by the rider, critical riding situations result, for example, when braking. With electric bicycles, this problem is exacerbated by the significantly higher speeds. At the same time, the demands for comfort are increasing, especially as electric bicycles reach other or additional target groups of riders.

[0003] Thus, devices and methods for adapting the center of gravity of an electric bicycle are known from the state of the art. However, there is a need to further improve the known devices and methods.

[0004] SUMMARY OF THE PRESENT EMBODIMENT It is therefore an object of the present invention to provide an apparatus, system, bicycle and method for changing the center of gravity of a bicycle depending on the situation, which further enhances safety for a cyclist.

[0005] The present invention provides an apparatus according to claim 1 which achieves the technical object. This object is further achieved by a system according to claim 16, a bicycle according to claim 17 and a method according to claim 18. Advantageous designs are the subject matter of the dependent claims.

[0006] Specifically, this object is achieved by a situation-adaptive center of gravity changing device for a bicycle, in particular an electric bicycle, comprising an actuator for changing the center of gravity, at least one sensor for monitoring the riding conditions of the bicycle, and a control unit for receiving and processing data from the sensor, determining a situation-adaptive center of gravity of the bicycle, and outputting a corresponding control signal to the actuator for performing the change of the center of gravity.

[0007] According to the present invention, the adjustment speed of the center of gravity change can be adapted to the riding state of the bicycle. In particular in critical riding situations, it is advantageous for the center of gravity of the bicycle to be changed as quickly as possible to increase the safety of the cyclist. For example, if the ABS sensor detects a safe limit braking or a limit lean of the bicycle, it is advantageous to lower the center of gravity quickly.

[0008] It should be noted here that in the context of the present invention, a riding situation should be understood not only as a riding motion of a bicycle, but also as a stationary motion. The general term bicycle also includes single-track muscle-powered bicycles, electric bicycles or pedelecs, as well as multi-track cargo or transport bicycles or freight bicycles (muscle-powered or electric-powered).

[0009] Preferably, the actuator is used to change the centre of gravity of the bicycle by adjusting the height of the seat post.

[0010] Also, by lowering the seat post, the rider can stand firmly with both feet on the ground, while in the non-critical riding mode, a more ergonomic seat position can be achieved, these positions can be approached automatically according to the appropriate presets.

[0011] According to an advantageous embodiment of the invention, the actuator can have at least one drive unit and a gear change unit driven by the drive unit, which can for example simply be operated by an accumulator.

[0012] The different adjustment speeds of the seat post can be realized in a simple manner in that the gear shifting unit has a shiftable derailleur with at least two different ratios, the ratio of which can be selected depending on the riding conditions of the bicycle, so that the adjustment speed in the vertical direction of the seat post is adapted to the riding conditions of the bicycle.

[0013] An advantageous design can be achieved if the gear unit has a freewheel that depends on the direction of rotation in order to adapt the gear ratio to the riding conditions of the bicycle. The freewheel can be used, for example, to lock the gear stages in one direction of rotation and release them in the opposite direction, so that the full gear ratio of the gear unit is available in the ascending direction and only a lower partial ratio is available in the descending direction. This allows the adjustment speed in the descending direction to be significantly increased.

[0014] For example, an electric motor can be used as the drive unit and a single or multi-stage planetary gear can be used as the transmission.

[0015] An alternative advantageous embodiment of the invention provides that by suitable design of the gear shifting unit and / or the motor characteristic curve in the ascending / descending direction, the adjustment speed of the seat post is adapted to the riding conditions of the bicycle.

[0016] Furthermore, a force compensation element can be advantageously provided which supports the extension movement of the seat post in the upward direction. A pressurizable spring bellows can be provided as force compensation element, which supports the extension movement of the seat post in the upward direction. If the seat post has additional spring means, the bellows can also advantageously be designed as a pressure accumulator for the spring means.

[0017] Alternatively, it is conceivable to provide a gas spring element as the force compensation element.

[0018] In an advantageous further development of the invention, the actuator can comprise a drive designed as an electric spindle drive and arranged in a housing having a drive unit and a gear unit driven by the drive unit, a spindle that can be driven in rotation by the drive unit about a rotation axis and is threadedly engaged with the spindle nut so that the spindle nut is axially non-rotatably displaceable in the housing, and a seat tube as an adjustment element for adjusting the height of the seat post, which can be displaced along a displacement axis by the drive unit relative to the drive unit.

[0019] Here, the spindle nut can be connected to the adjusting element in a snap-fit ​​manner, such that the connection is capable of absorbing forces in the pressure direction, the snap-fit ​​can be achieved simply by a clip connection and the spindle nut can be produced cost-effectively.

[0020] To improve the riding comfort, according to an advantageous embodiment of the invention, the seat post has a seat suspension, for example a parallelogram suspension seat post, which can be adapted, for example, using exchange spring elements.

[0021] Preferably, a gas force support can be provided for adjusting the seat suspension, the axially adjustable adjustment element for the gas force support having a pressure chamber which can be variably filled with gas by means of a valve.

[0022] Mechanical seat suspensions can be adjusted as needed using gas force in a pressure chamber. The valve allows the suspension to be easily adjusted at any time without removing the seat post. At the same time, the mechanism can be better and permanently protected from external influences such as weather, rain, mud, etc., since replacement is no longer necessary to replace the suspension and the suspension is no longer easy to disassemble. Individual adjustments of the suspension can be made only through the valve.

[0023] The pressure chamber can be limited by a plunger arranged in the seat tube on the side facing the seat suspension so that it is axially displaceable depending on the gas volume in the pressure chamber, and a tappet arranged on the plunger is operatively connected to the mechanical seat suspension so that the axial displacement of the plunger causes a change in the seat suspension. If the mechanical seat suspension is designed as a parallelogram spring unit with articulated sides and support components and spring elements, the spring force can be adjusted as required by adjusting the joints. The spring elements can be, for example, mechanical compression coil springs or deformable elastomer elements. As already mentioned, it is no longer necessary to replace the spring elements to adjust the suspension, and the spring elements and the joints can be better and permanently protected from external influences.

[0024] According to a further advantageous embodiment of the invention, the sensor can be designed as a proximity switch designed to scan the contour of the brake disc of the bicycle.

[0025] The brake disc can have a cam for a mating connection with the support, which can be scanned by a proximity switch. This allows for a very fine signal resolution without additional sensor elements. At the same time, the proximity switch and the brake disc provide a robust and cost-effective system to implement.

[0026] This object is further achieved by a system for adaptively changing the centre of gravity of a bicycle, in particular an electric bicycle, equipped with one of the above-mentioned devices according to the invention and an electrically actuable mainstand and / or a semi-automatic or fully automatic hand brake.

[0027] Furthermore, this object is achieved by a bicycle equipped with the above-mentioned device according to the invention or with the above-mentioned system according to the invention.

[0028] A further aspect of the invention is a method for adaptively varying the center of gravity of a bicycle, in particular an electric bicycle, comprising the steps of: capturing sensor data indicative of a riding status of the bicycle; evaluating the sensor data and determining a situation-adaptive center of gravity of the bicycle; generating a control signal for modifying the center of gravity of the bicycle; outputting a control signal to an actuator to effect a change in the center of gravity; and adjusting the adjustment speed of the change in the center of gravity to suit the riding conditions of the bicycle.

[0029] Preferably, the center of gravity is altered by adjusting the height of the bicycle's seat post using an actuator, which advantageously adjusts the height of the seat post faster in a downward direction than in an upward direction, thereby mitigating critical riding situations.

[0030] In a preferred embodiment, the centre of gravity can be altered by means of a device such as those described above.

[0031] The present invention will be described below with reference to several embodiments. Identical or similar components are provided with the same reference numerals. The drawings, the specification and the claims contain a number of combinations of features. Those skilled in the art can also conveniently consider these features individually and combine them to form advantageous further combinations. Thus, individual or several embodiments can be advantageously combined with each other. [Brief description of the drawings]

[0032] The drawings are as follows: [Figure 1] 1 shows a schematic diagram of an actuator of a device according to the invention for adaptively modifying the center of gravity of a bicycle; [Diagram 2] 2 shows a cross-sectional view of the actuator shown in FIG. [Diagram 3] FIG. 2 shows a side view of an actuator having a spring-type seat suspension, excluding the variable speed unit, illustrating one embodiment of the device according to the present invention. [Figure 4] FIG. 4 shows a side view of the device according to FIG. 3, without the gear unit of the actuator with seat-integrated spring suspension. [Diagram 5] 5 shows a cross-sectional view of the device shown in FIG. [Figure 6] 6 shows an enlarged portion Q of the cross section shown in FIG. 5. [Figure 7] 3 shows a cross-sectional view of another embodiment of a device according to the invention; [Figure 8] 8 shows an enlarged portion Q of the cross section shown in FIG. [Figure 9] 8 shows an enlarged portion R of the cross section shown in FIG. 7.

[0033] 1 shows an actuator 2 of a device 1 for adapting the center of gravity of a bicycle. In the context of the present invention, the bicycle can be a single-track muscle-powered bicycle, an electric bicycle, or a pedelec, or a multi-track load, transport, or cargo bicycle (muscle-powered or electric-powered).

[0034] The device 1 according to the invention for adapting the centre of gravity of a bicycle to increase bicycle safety comprises an actuator 2 for adapting the centre of gravity, at least one sensor for monitoring the riding conditions of the bicycle, and a control unit for receiving and processing data from the sensor, determining the centre of gravity of the bicycle to the circumstances and outputting corresponding control signals to the actuator for carrying out the modification of the centre of gravity.

[0035] For example, the speed signal can be generated by scanning the contour of the brake disc, for which purpose one or more proximity switches can be used, by means of which a spiral arm of the brake disc is scanned.

[0036] Alternatively, a brake disc made of steel, for example, arranged coaxially on a support made of aluminum, may have preferably 18 cams directed inwards for a snap-fit ​​connection with the support. These may be scanned by a suitable sensor, for example a proximity switch, to generate a signal about the speed of the bicycle. As a result, no additional sensor elements may be required.

[0037] The adjustment speed of the center of gravity change is adapted to the riding conditions of the bicycle, so that the center of gravity of the bicycle can be changed as quickly as possible, particularly in critical riding situations. For example, it is advantageous to quickly lower the center of gravity when safety-critical braking is detected by an ABS sensor or when a safety-critical bicycle lean is detected by a suitable sensor.

[0038] In the above-described embodiment, the center of gravity is changed by adjusting the height of the bicycle's seat post 12, but this is not limiting. The height can be adjusted automatically depending on the riding position of the bicycle. It is also conceivable that the height adjustment can be additionally controlled by the cyclist.

[0039] Also, by lowering the seat post 12, the rider can stand firmly with both feet on the ground, while in the non-critical riding mode, a more ergonomic seat position can be achieved, these positions can be automatically approached according to appropriate presets.

[0040] The actuator 2 comprises at least one drive unit 3 and a gearbox unit 4 driven by the drive unit 3, for example an electric motor is used as the drive unit and a single or multi-stage planetary gear is used as the gearbox. In a bicycle with an electric drive, the drive unit 3 can be operated using the battery of the electric drive.

[0041] According to the illustrated embodiment, the actuator 2 can be designed as an electric spindle drive.

[0042] As can be seen in particular from Fig. 2 showing the cross section, the actuator 2 comprises a drive arrangement arranged in a housing 5 with a drive unit 3 and a gear unit 4 driven by the drive unit 3, and a spindle 6 which can be driven in rotation by the drive unit 3 about a rotation axis and which is in threaded engagement with a spindle nut 7. The spindle nut 7 is arranged axially displaceable in the housing 5 or in a profile tube 8 arranged in the housing 5. Furthermore, the actuator 2 has a seat tube 9 designed as an adjustment element for adjusting the height of the seat post 12, which can be displaced by the drive unit 3 relative to the drive along a displacement axis.

[0043] The profile tube 8, preferably made of plastic, allows an internal torque support for the axially displaceable spindle nut 7, which is connected to the seat tube 9 in such a way that the connection can absorb forces in the pressure direction. A simple clip connection is conceivable. For this purpose, the spindle nut 7 can have elastic spring arms that can be clipped into recesses in the profile tube 8. The spindle nut 7 can also be connected directly to the seat tube 9 via a corresponding connection.

[0044] The profile tube 8 has one or more nose-like projections 10 on its outside, which engage in complementary recesses 11 in the housing 5 to prevent rotation or to transmit torque. Furthermore, a further torque-transmitting connection can be made by partially deforming the housing 5, the material of the housing 5 being pressed into the material of the profile tube 8. This connection also allows a seal between the profile tube 8 and the housing 5.

[0045] In this embodiment, the housing 5 forms a fixed part of a seat post which can be attached to the frame of the bicycle, while the adjustment element 9 forms a height-adjustable part of the seat post 12 to which a bicycle seat 19 can be attached. When a situation is detected in which a change of the bicycle's centre of gravity is advantageous, the drive unit 3 is activated by the control unit, which causes the seat post 9 to be moved axially along the displacement axis accordingly, so that a change of the centre of gravity can be achieved by adjusting the height of the bicycle seat post.

[0046] The seat post height can be adjusted down faster than up, which can greatly ease critical riding situations.

[0047] Different adjustment speeds of the seat post 12 can be adapted to the riding conditions of the bicycle, for example by suitable design of the gear unit and / or the motor characteristic curve in the ascending / descending direction.

[0048] An alternative embodiment provides for a gear shifting unit designed as a shiftable derailleur having at least two different ratios, the ratios of which can be selected depending on the riding conditions of the bicycle such that the adjustment speed of the seat post 12 in the ascending / descending direction is adapted to the riding conditions of the bicycle.

[0049] In order to adapt the transmission ratio to the riding conditions of the bicycle, the transmission unit can have, for example, a freewheel that is dependent on the direction of rotation. By means of the freewheel, the gear stages can be locked in one direction of rotation and released in the opposite direction, so that the full transmission ratio of the gear unit is available in the ascending direction and only the lower partial transmission ratios are available in the descending direction. This allows the adjustment speed in the descending direction to be significantly increased.

[0050] It is also conceivable to design the device with a force compensation element which supports the extension movement of the seat post 12 in the upward direction. A pressurizable spring bellows can be provided as force compensation element, which supports the extension movement of the seat post in the upward direction. If the seat post 12 has additional spring means, the bellows can advantageously also be designed as a pressure accumulator for the spring means. It is also conceivable to provide a gas spring element as force compensation element.

[0051] The described device can be combined with an electrically operated kickstand and / or a semi-automatic or fully automatic handbrake as part of a system for adapting the centre of gravity of the bicycle to the conditions.

[0052] The device 1 may further comprise a mechanical seat suspension 13, shown in FIG. 3, to which the seat tube 9 is connected. The mechanical seat suspension 13 may be designed as a parallelogram spring seat post with articulated side and support components 14, 15, 16, 17 and a spring element 18. Here, the seat tube 9 is connected to a first support component 16, the bicycle seat 19 is connected to an opposite second support component 17, and the side components 14, 15 are articulated to the support components 16, 17, respectively, to form a parallelogram. It is known that a spring element 18, for example designed as a mechanical compression coil spring, is arranged between two of the parallelogram components 14-17 to provide the suspension. The seat suspension 13 is connected to the seat tube 9 by the first support component 16 or by a connecting element 20 attached to the first support component 16.

[0053] Figure 3 shows the seat suspension 4 in a deflected state in which the two support components 16, 17 have a maximum distance between them. In a compressed state, shown for example in Figure 4, the spring element 19 is compressed such that the distance between the support components 16, 17 is reduced.

[0054] The mechanical seat suspension 13 can be designed with minimal spring force because the device 1 provides gas force support as described below. The gas force support is parallel to the seat suspension, allowing the overall suspension force to be adjusted.

[0055] Figure 5 shows a cross section of the device 1 shown in Figures 3 and 4. As can be seen, the actuator is designed as an electric spindle drive, whose spindle 6 is arranged in a seat tube 9.

[0056] For gas force support a pressure chamber 22 is provided in the seat tube 9 which can be variably filled with gas or air by means of a valve 23. The mechanical seat suspension can be adjusted as required by the gas force in the pressure chamber 22. The suspension can be easily adjusted at any time via the valve 23 using an air pump without having to remove the seat post.

[0057] The pressure chamber 22 is limited on the side facing the seat suspension 13 by a plunger 24 arranged axially displaceably in the seat tube 9 .

[0058] The plunger 24 is sealingly guided in the seat tube 9 and has a tappet 25 which also extends sealingly through a recess in the connecting component 20. As can be seen in FIG. 5, the free end of the tappet 25 protrudes from the connecting component 20 and is operatively connected via a cam 26 to the mechanical seat suspension 13, such that an axial displacement of the plunger 24 causes a modification of the seat suspension by adjusting the parallelogram components 14-17.

[0059] On the actuator side, the pressure chamber 22 is limited by a sealing separation piston 27, which can be axially displaced in the seat tube 9 by the spindle 6. The seal is achieved, for example, by an O-ring 28 arranged in a ring groove of the separation piston 27. In this embodiment, the spindle end 29 facing away from the actuator is in rotatable contact with the separation piston 27 or with a protrusion 30 of the separation piston 27 in order to minimize frictional forces. As can be seen from FIG. 6, the protrusion 30 is arranged at the bottom of a recess 31 of the separation piston 27, so that an additional guiding of the spindle end 29 is possible. Here too, the pressure chamber 22 is limited on the side facing the seat suspension 13 by a plunger 24, which can be axially displaced in the seat tube 9, the entire plunger surface of the plunger 24 being effective. This allows a relatively large adjustment force to be generated on the tappet 25.

[0060] Due to the gas present in the pressure chamber 22, the separating piston 27 remains in contact with the spindle 6 and is displaced in the seat tube 9 according to the adjustment movement. The gas pressure can therefore act on the entire separating piston surface which supports the extension force of the actuator in addition to the spring force of the seat suspension 13.

[0061] Since the size of the pressure chamber 22 is stroke-dependent in this embodiment, the gas output support can be adjusted in dependence on the stroke.

[0062] Figures 7 to 9 show further embodiments. Figure 7 shows a cross section PP of another embodiment of the device 1. As can be seen, the actuator 2 is designed as an electric spindle drive, whose spindle 6 is arranged in a seat tube 9.

[0063] The spindle 6 is driven to rotate about a rotation axis by a drive unit (not shown) of the drive device, and is threadedly engaged with a spindle nut 7 (not shown). The spindle nut 7 itself is provided for axial displacement within the housing 5 and is non-rotatably connected to a seat post 9, which can be displaced along an adjustment axis by the actuator 2 relative to the drive device for height adjustment of the seat post 12.

[0064] The connection between the spindle nut 7 and the seat tube 9 is designed so that it can absorb forces in the pressure direction. For this purpose, an easy-to-manufacture clip connection is conceived, in which the spindle nut 7 has elastic spring arms which can be clipped into recesses in the seat tube 9.

[0065] In this embodiment, the housing (not shown) forms a fixed portion of a seat post 12 which can be attached to the frame of a bicycle.

[0066] For gas force support a pressure chamber 22 is provided in the seat tube 9, which pressure chamber 22 can be variably filled with air by means of a valve 13. The mechanical seat suspension 13 can be adjusted as required by means of the gas force in the pressure chamber 22. The suspension can be easily adjusted at any time via the valve 23 using an air pump without having to remove the seat post 12.

[0067] On the side facing the seat suspension 13 , the pressure chamber 22 is limited by a plunger 24 arranged axially displaceably in the seat tube 9 .

[0068] The plunger 24 is sealingly guided in the seat tube 9 and has a tappet 25 which extends sealingly through a recess in the connecting component 20. As can be seen in FIG. 7, the free end of the tappet 25 protrudes from the connecting part 20 and is operatively connected via a cam 26 to the mechanical seat suspension 13, such that an axial displacement of the plunger 24 causes a modification of the seat suspension by adjusting the parallelogram components 14-17.

[0069] On the actuator side, the pressure chamber in the embodiment example shown in Figures 7 to 9 is limited by a separation tube 32 which at least partially surrounds the spindle 6 and protrudes into the seat tube 5. The separation tube 32 is approximately pot-shaped and adjoins the seat tube 9 with a separation tube end 33 which is cross-sectionally enlarged. For this purpose, the seat tube 9 has a radially inwardly facing shoulder 34 which can be formed, for example, by molding the seat tube material. To seal the separation tube end 33 against the seat tube 9, a washer 35 with a radially extending sealing element 36 can also be arranged between the separation tube end 33 and the shoulder 34.

[0070] When the actuator is actuated, i.e. when the seat tube 9 is adjusted, the separation tube 32 moves along the adjustment axis together with the seat tube 9, so that the gas force support in this embodiment is independent of the stroke.

[0071] From Fig. 8, which shows an enlarged section Q of Fig. 7, it can be seen that the separation tube 32 is guided at its further end 37 in a guide element 38 in the seat tube 9, which guide element 38 has on its outer side an axially extending recess 39. Through the recess 39, the air supplied into the pressure chamber 22 via the valve 23 can also reach into the annular space 40 which the separation tube 32 forms with the seat tube 9. The pressure chamber 22 thus extends from the plunger 24 to the separation tube end 33, providing a large pressure volume and a flat gas force characteristic curve.

Claims

1. A device (1) for adapting the center of gravity of a bicycle, in particular an electric bicycle, comprising: an actuator (2) for modifying the centre of gravity of the bicycle; at least one sensor that monitors a riding status of the bicycle; a control unit receiving and processing data from said sensors, determining the centre of gravity of the bicycle adapted to said situation and outputting corresponding control signals to said actuators (2) in order to effect said modification of the centre of gravity; Equipped with The device (1) is capable of adapting the adjustment speed of the center of gravity modification to the riding conditions of the bicycle.

2. 2. The device (1) according to claim 1, characterized in that the modification of the centre of gravity is brought about by the actuator (2) by adjusting the height of a seat post (12) of the bicycle.

3. 3. The device (1) according to claim 2, characterized in that the actuator (2) comprises at least one drive unit (3) and a transmission unit (4) driven by said drive unit.

4. 4. The device (1) according to claim 3, characterized in that the gear shifting unit (4) comprises a shiftable transmission having at least two different ratios, the ratios of which are selectable depending on the riding state of the bicycle, whereby the adjustment speed in the ascending / descending direction of the seat post (12) is adapted to the riding state of the bicycle.

5. 5. The device (1) according to claim 4, characterized in that the transmission unit (4) comprises a freewheel depending on the direction of rotation in order to adapt the transmission ratio to the riding state of the bicycle.

6. The device (1) according to any one of claims 3 to 5, characterized in that the adjustment speed of the seat post (12) is provided to suit the riding conditions of the bicycle by a suitable design of the gear shifting unit (4) and / or by motor characteristics in the ascending and descending direction.

7. Device (1) according to any one of claims 2 to 6, characterised in that a force compensation element is provided, said force compensation element supporting the extension movement of the seat post (12) in the upward direction.

8. 8. The device (1) according to claim 7, characterized in that as the force compensation element a spring bellows is provided which can be subjected to pressure, said spring bellows supporting the extension movement of the seat post (12) in the upward direction.

9. 9. The device (1) according to claim 8, characterized in that the seat post (12) has additional spring means and that the spring bellows is designed as a pressure accumulator for the spring means.

10. 8. The device (1) according to claim 7, characterized in that a gas spring element is provided as a force compensation element, said gas spring element supporting the extension movement of the seat post (12) in the upward direction.

11. The actuator (2) is designed as an electric spindle drive, a drive device arranged in a housing (5) and having the drive unit (3) and the variable speed unit (4) driven by the drive unit (3); a spindle (6) that can be rotatably driven about a rotation axis by the drive unit (3) and that is threadedly engaged with a spindle nut (7) such that the spindle nut (7) is axially displaceable in a rotationally fixed manner within the housing (5); The device (1) according to any one of claims 3 to 10, characterized in that it comprises a seat tube (9) as an adjustment element (9) for adjusting the height of the seat post (12), the seat tube (9) being displaceable relative to the drive device by the drive unit (3) along a displacement axis.

12. 12. Device (1) according to claim 11, characterized in that the spindle nut (7) is in a snap-on connection with the adjusting element (9), said connection being capable of absorbing forces in the direction of pressure.

13. Device (1) according to any one of claims 2 to 12, characterised in that the seat post (12) comprises a seat suspension (13).

14. 14. The device (1) according to claim 13, characterized in that a gas force support is provided for adjusting the seat suspension (13), and the axially adjustable adjustment element (9) for the gas force support has a pressure chamber (22) which can be variably filled with gas by means of a valve (23).

15. Device (1) according to any one of the preceding claims, characterized in that the sensor is designed as a proximity switch designed to scan the contour of the brake disc of the bicycle.

16. A system for adapting the centre of gravity of a bicycle, in particular an electric bicycle, comprising: The composition according to any one of claims 1 to 15, A system comprising a device (1) with an electrically operated centre stand and / or a semi-automatic or fully automatic hand brake.

17. A bicycle comprising a device (1) according to any one of claims 1 to 15 or a system according to claim 16.

18. A method for adaptively changing the center of gravity of a bicycle, in particular an electric bicycle, comprising: - capturing sensor data indicative of a riding status of the bicycle; - evaluating the sensor data and determining a situation-adaptive center of gravity of the bicycle; - generating a control signal for modifying the centre of gravity of the bicycle; - outputting said control signals to actuators (2) to effect said modification of the centre of gravity; - adjusting the rate of adjustment of the change in the center of gravity to suit riding conditions of the bicycle.

19. 19. The method according to claim 18, characterized in that the change in the centre of gravity is brought about by adjusting the height of a seat post (12) of the bicycle by means of the actuator (2).

20. 20. The method according to claim 19, characterized in that the height adjustment of the seat post (12) is faster in a downward direction than in an upward direction.

21. Method according to any one of claims 18 to 20, characterized in that said modification of the centre of gravity is performed by a device according to any one of claims 1 to 15.

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