Seat post assembly
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- BASTILLE CYCLES
- Filing Date
- 2023-06-29
- Publication Date
- 2026-06-09
AI Technical Summary
Existing bicycle seat post fixing systems require tools for adjustment and are cumbersome when frequent adjustments are needed, especially in shared or folding bicycles.
A seat post assembly with a link rod and rotatable seat support that allows easy locking and unlocking through saddle pivoting, using a lever mechanism for force amplification, enabling tool-free height adjustments.
Facilitates easy, tool-free height adjustments suitable for shared bicycles and allows seat post retraction for folding bicycles, enhancing user convenience and functionality.
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a seat post assembly. This assembly can be particularly attached to a bicycle. More specifically, the present invention relates to a seat post assembly provided with a fixing system that enables changing and fixing the height of the seat post.
Background Art
[0002] There are numerous fixing systems for bicycle seat posts. The fixing systems used for bicycle seat posts (and also for handlebars) include a link rod extending inside the seat post and a wedge connected to this link rod. The link rod can move between a low position where the wedge does not interfere with the sliding of the seat post inside the seat tube surrounding the seat post and a high position where the wedge interferes with this sliding to fix the seat post in a predetermined position. An exemplary system of this kind is shown in Patent Document 1. Such a fixing system has been evaluated for its robustness and reliability. However, the operations required for fixing and releasing this system are not easy and often require tools. This drawback can be tolerated when the height of the seat post is adjusted only once to fit the size of its sole user. In contrast, this drawback becomes immediately troublesome when it is necessary to frequently adjust the height of the seat post, as in the case of a bicycle shared among multiple users. Furthermore, this drawback becomes troublesome when it is frequently necessary to retract the seat post as far as possible into the seat tube so as to reduce the bulk of the bicycle, as in the case of most folding bicycles. Therefore, there is a need for a seat post fixing system that is easy to handle and does not require any tools.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Means for Solving the Problem
[0004] The seat post assembly according to the present invention includes a seat post adapted to be mounted in a slidable manner within a seat tube, a link rod extending inside the seat post, the link rod being movable between a lower position and a higher position relative to the seat post, a base mounted at the upper end of the seat post, a seat support on which a saddle can be mounted, the seat support being mounted to the base, and a fixing system. The fixing system is operable between an unlocked position where the fixing system does not prevent the sliding of the seat post inside the seat tube and a locked position where the fixing system prevents the sliding and fixes the seat post at a predetermined position inside the seat tube.
[0005] The fixing system is actuated by the movement of the link rod between its higher and lower positions.
[0006] The seat support is mounted to the base in a manner rotatable about a first axis, and is connected to the link rod such that the rotation of the seat support about the first axis causes the link rod to move between its higher and lower positions.
[0007] Therefore, when the saddle is mounted on the seat support, the user can lock and unlock the fixing system simply by pivoting the saddle together with the seat support about the first axis. Therefore, the required operation is particularly easy.
[0008] In certain embodiments, the seat support is connected to a link rod by a lever pivotally attached to the base for pivoting about a second axis, with a first arm of the lever extending on one side of the second axis and connected to the link rod to move the link rod between its high and low positions, and a second arm of the lever extending on the other side of the second axis and being rotated and moved about the second axis by rotation of the seat support about a first axis. This lever connection has the advantage of being simple and robust. Additionally, the lever allows for amplification of the force applied by the user by adjusting the length of each arm of the lever. Thus, only a moderate force is sufficient to move the link rod between its high and low positions to lock and unlock the fixing system.
[0009] The present invention also relates to a vehicle comprising the seat post assembly described above, a frame having a seat tube in which the seat post is slidably mounted, and a saddle mounted on the seat support. This vehicle can be a bicycle or any other vehicle equipped with a saddle.
[0010] The above and other features and advantages, as well as other features and advantages, will become apparent upon reading the following detailed description. This detailed description refers to the accompanying drawings.
Brief Description of the Drawings
[0011] The accompanying drawings are schematic diagrams and are not necessarily to scale, and are mainly intended to illustrate the principles of the present invention. In the accompanying drawings, the same element (or a part of the element) is identified by the same reference numeral throughout the plurality of figures.
[0012]
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
DETAILED DESCRIPTION OF THE INVENTION
[0013] In the following, with reference to the examples shown in the accompanying drawings, a plurality of specific embodiments of the proposed seat post assembly will be described in detail. These embodiments show the features and advantages of the present invention. However, it should be noted that the present invention is not limited to these embodiments.
[0014] In a plurality of specific embodiments, as in the examples shown in each figure, the seat post assembly includes a seat post 1 designed to be slidably mounted inside a seat tube 20. The upper end 1A of the seat post 1 supports a seat support 10, and a saddle 18 is installed thereon. FIG. 3 shows the saddle 18 in its use position. In this position, the user sits on the upper surface 18S of the saddle 18.
[0015] In this application, horizontal and vertical are determined based on the use position of the saddle 18 shown in FIG. 3. In this use position, the upper surface 18S of the saddle is substantially horizontal. The upper and lower parts are determined based on the vertical direction. The front and rear are determined based on the horizontal direction and the normal position of the user sitting on the saddle 18 facing forward.
[0016] In the examples shown in each figure, the saddle 18 is provided with a plurality of mounting rails 19 on its lower surface. These rails 19 extend in the longitudinal direction of the saddle 18. These rails 19 are held within jaws 4 provided on both sides of the seat support 10. These jaws 4 are tightened around the rails 19 by screws 3. This mounting system complies with current standards so that most commercially available saddles with rails can be mounted on this seat support 10. Of course, other mounting systems for mounting the saddle 18 on the seat support 10 can also be envisioned.
[0017] The seat post assembly further includes a fixing system 2 for fixing the seat post 1 at a predetermined position inside the seat tube 20, and a link rod 17 extending inside the seat post 1 and connected to the fixing system 2.
[0018] The link rod 17 is movable relative to the seat post 1 between the low position shown in FIG. 4 and the high position shown in FIGS. 3 and 5.
[0019] The fixing system 2 operates by the link rod 17 moving between its high and low positions. The fixing system 2 can operate between an unlocked position and a locked position. In the unlocked position, the fixing system does not prevent the sliding of the seat post 1 inside the seat tube 20, and in the locked position, the fixing system prevents the sliding and fixes the seat post 1 at a predetermined position inside the seat tube 20.
[0020] In this example, when the link rod 17 is in the lower position, the fixing system 2 is in the unlocked position and does not prevent the sliding of the seat post 1 inside the seat tube 20. When the link rod 17 is in the higher position, the fixing system 2 is in the locked position, preventing the sliding and fixing the seat post 1 at a predetermined position inside the seat tube 20. Therefore, the higher and lower positions of the link rod 17 respectively correspond to the unlocked and locked positions of the fixing system 2. However, the reverse correspondence can also be assumed without departing from the scope of the present invention.
[0021] In certain embodiments, as shown in the examples in each figure, the link rod 17 passes through the seat post 1, and the lower end 17B of the link rod 17 extends beyond the lower end 1B of the seat post 1. The fixing system 2 is mounted on the lower end 17B of the link rod 17 such that the link rod 17 moves a part of the fixing system 2 during its movement to activate the fixing system 2.
[0022] In certain embodiments, the fixing system 2 includes a wedge 30. The lower end 1B of the seat post 1 is beveled along an inclined surface 31 that forms a non-zero angle, for example an angle between 30° and 60°, with respect to a plane orthogonal to the main axis X of the seat post 1. The wedge 30 is supported by the link rod 17 and has an inclined surface 30A facing the inclined surface 31. When the link rod 17 moves from its lower position to its higher position, the link rod 17 causes the inclined surface 30A to slide against the inclined surface 31 and lift the wedge 30, thereby causing the displacement of the wedge 30 from the main axis X of the seat post 1. Thereafter, as shown in FIGS. 3 and 5, the wedge 30 presses against one inner wall of the seat tube 20 and presses the seat post 1 against the opposite inner wall. The resulting friction prevents the sliding of the seat post 1 inside the seat tube 20, and as a result, the seat post 1 is fixed at a predetermined position.
[0023] In the present application, a wedge or a chuck means a movable mechanical member to which a force for prevention can be applied in order to prevent relative movement between components in an assembly composed of a plurality of components. In this case, the wedge 30 enables prevention of relative movement between the seat post 1 and the seat tube 20.
[0024] In the following, another example of the fixing system 2 will be described with reference to FIGS. 6 to 9. These examples of the fixing system 2 have the advantages of being robust and reliable. In particular, they are more reliable than systems that use a collar to clamp the seat tube against the seat post.
[0025] This seat post assembly further includes a base 6 installed at the upper end 1A of the seat post 1. In this example, the base 6 includes a sleeve 26 that is fitted into and installed at the upper end 1A of the seat post 1. The seat support 10 is attached to the base 6 in a rotatable manner around the first axis 11, and the seat support 10 is connected to the link rod 17 such that the link rod 17 moves between its high position and its low position by rotation of the seat support 10 around the first axis 11.
[0026] In certain embodiments, as in the examples shown in each figure, the upper part of the base 6 extends rearward from the seat post 1, that is, from the sleeve 26. The upper part of the base 6 has a front wall that forms or supports a hook 16 and two side walls that terminate in two arms 6A toward the rear. The upper part of the base 6 is hollow and has no lower wall and no rear wall.
[0027] The rear part 10B of the seat support 10 is attached between the two arms 6A in a rotatable manner around the first axis 11. Thereby, the seat support 10 can depict a relative rotational movement with respect to the base 6.
[0028] In this example, the first axis 11 is a rotating axis embodied by two screws 11A facing each other and arranged in the same direction. These screws 11A are screwed into the arm 6A from the outside. These screws 11A penetrate through the thickness of the arm 6A and are accommodated in cylindrical holes that penetrate through the rear part 10B of the seat support 10. These screws together form a (two-part) shaft. The seat support 10 is supported by this shaft so as to pivot around it.
[0029] Of course, other configurations for realizing the connection between the seat support 10 and the base 6 can also be assumed. For example, two spindles can be extended on both sides of the rear part 10B of the seat support 10. These spindles can be respectively supported by two bearings formed on the arm 6A. According to another example, the first rotating axis 11 can be a (single-piece) shaft that penetrates through the seat support 10 and the arm 6A.
[0030] According to another example, the first rotating axis 11 is not embodied by any component, but is merely a virtual straight line, and a rotational movement is performed around this virtual straight line. In the latter case, the connection between the seat support 10 and the base 6 is realized, for example, by fitting an annular groove to an annular rib.
[0031] In certain embodiments, the seat support 10 is connected to the link rod 17 by a lever 7 attached to the base 6 in a manner pivotable around the second axis 8. The lever 7 includes two arms extending on both sides of the second axis 8. The first arm 7A of the lever extends on one side of the second axis 8 and is connected to the link rod 17 so that the link rod 17 moves between its high position and low position. The second arm 7B of the lever extends on the other side of the second axis 8 and rotates around the second axis 8 due to the rotation of the seat support 10 around the first axis 11.
[0032] In this example, the second axis 8 is a rotating axis embodied by a shaft passing through the lever 7 and is supported by two bearings formed on the walls on both sides of the base 6. However, other configurations for connecting the lever 7 are also conceivable. For example, the second rotating axis 8 can be formed by two spindles extending on both sides of the lever 7. The lever 7 may be provided with a hole 9 through which the second axis 8 can pass.
[0033] In certain embodiments, the first arm 7A of the lever is longer than the second arm 7B. Further, the lever 7 may have a bent shape. The second axis 8 is located at the bent portion of the lever 7.
[0034] In certain embodiments, the lever 7 is housed inside the base 6 between the walls on both sides of the base 6 (i.e., between the arms 6A). Similarly, the upper end 17A is housed inside the base 6, and the link rod 17 passes through the sleeve 26. Therefore, the mechanism of the fixing system is protected from external impacts. Since this mechanism is in a position out of reach of the user's hand, the risk of trapping can be avoided.
[0035] In certain embodiments, the upper end 17A of the link rod 17 passes through the first arm 7A of the lever and has an upper stop portion 27A and a lower stop portion 27B on both sides of the first arm 7A. The first arm 7A hits the upper stop portion 27A when the link rod 17 is in a high position and hits the lower stop portion 27B when the link rod 17 is in a low position. In other words, when the first arm 7A rises, the first arm 7A contacts the upper stop portion 27A and pulls up the post 27. Conversely, when the first arm 7A descends, the first arm 7A contacts the lower stop portion 27B and pushes down the post 27. In the examples shown in each figure, the stop portions 27A, 27B have the shape of a collar, and the end of the first arm 7A forms a fork. This fork is fitted around the post 27 between the stop portions 27A, 27B.
[0036] In certain embodiments, as shown in each figure, the seat support 10 is rotatable about a first axis 11 and movable between the following three positions. - A support position corresponding to the use position of the saddle 18. In this position, the seat support 10 is correctly upward and supported on the base 6. - An inverted position. In this position, the seat support 10 is tilted backward of the base 6. - An intermediate position between the support position and the inverted position.
[0037] These three positions are shown in FIGS. 3, 5, and 4 respectively.
[0038] In FIG. 3, the seat support 10 is in the support position and the saddle 18 is in its use position. The upper surface 18S of the saddle is substantially horizontal so that a user can sit on it.
[0039] In FIG. 4, the seat support 10 is in the intermediate position, the saddle 18 is upright, and the upper surface 18S of the saddle is nearly vertical.
[0040] In FIG. 5, the seat support 10 is in the inverted position. The support 10 and the saddle 18 are tilted backward. The saddle is inverted and its upper surface 18S is downward.
[0041] The link rod 17 is in a high position when the seat support 10 is in the support position, in a low position when the seat support 10 is in the intermediate position, and in a high position again when the seat support 10 is in the inverted position.
[0042] In certain embodiments, the seat support 10 (in this case, the rear portion 10B of the seat support 10) supports the pin 12. Further, an oval opening 13 is provided in the second arm 7B of the lever 7. The oval opening 13 and the seat support 10 are configured such that while the seat support 10 rotates about the first axis 11, the pin 12 moves along therein within the oval opening 13. As shown in FIGS. 3-5, the movement of the pin 12 within the oval opening 13 pivots the lever 7 about the second axis 8.
[0043] While the seat support 10 rotates about the first axis 11, the pin 12 traces a circular path. In this example, the oval opening 13 curves in the same direction as the circular path. The curvature of the oval opening 13 is less than the curvature of the circular path of the pin 12.
[0044] In the following, with reference to FIGS. 3-5, the operation of the fixing system will be described.
[0045] As shown in FIG. 3, when the seat support 10 is in the support position, the pin 12 is located at the first end of the oval opening 13. At this time, the second arm 7B of the lever 7 is in the low position, and the first arm 7A is in the high position conversely. The first arm 7A contacts the upper stop portion 27A of the link rod 17 and pulls up the link rod 17. At this time, the link rod 17 is in the high position, the fixing system 2 is locked, and the seat post 1 is fixed at a predetermined position inside the seat tube 20.
[0046] In certain embodiments, the seat support 10 may include a connection system that enables connection of the seat support to the base 6 to hold the seat support 10 in the support position. For example, the seat support 10 may include a hook 5. The hook 5 is fitted into another hook 16 supported by the base 6. The hook 5 can be held in the engaged position by the compression spring 14. To disengage the hook 5 from the other hook 16, the user applies a force to the hook 5 that counteracts the force of the spring 14. To make this operation easier, the hook 5 may be provided with a tab or tongue that the user can push to disengage or remove the hook 5. The hook 5 can be attached to the seat support 10 in a rotatable manner about the shaft 15. Of course, other connection systems for connecting the seat support 10 to the base 6 can also be envisioned. For example, the other hook 16 can be replaced with an opening provided in the base 6 for hooking the hook 5.
[0047] To unlock the fixing system 2, the user removes the hook 5 and lifts the saddle 18 together with the seat support 10 to the intermediate position shown in FIG. 4. At this time, the pin 12 moves toward the middle of the oval opening 13. As a result, the second arm 7B of the lever 7 is lifted. At this time, the second arm 7B of the lever 7 is in a high position, and the first arm 7A is in a low position conversely. The first arm 7A contacts the lower stop portion 17B of the link rod and pushes down the link rod 17. At this time, the link rod 17 is in a low position, and the fixing system 2 is unlocked, so that the seat post 1 can slide freely inside the seat tube 20. This freedom of movement is schematically shown by double arrows in FIGS. 4 and 8.
[0048] In the case of a conventional (i.e., non-folding) bicycle, especially in the case of a bicycle shared among multiple users, when the fixing system 2 is unlocked, the height of the saddle 18 can be adjusted to the size of the new user. After adjusting the height of the saddle 18, the saddle 18 can be folded back toward its use position shown in FIG. 3 to lock the fixing system 2 and fix the saddle 18 in place.
[0049] In the case of a folding bicycle, when the fixing system 2 is unlocked, the seat post 1 can be retracted (i.e., lowered) as much as possible into the seat tube 20 so as to limit the size of the folded bicycle. Once the seat post 1 is retracted, the saddle 18 can be folded forward towards its use position shown in Fig. 3 to lock the fixing system 2 and fix the saddle 18 in a predetermined position.
[0050] As a variant, the saddle 18 can be tilted rearward together with the seat support 10 towards the inverted position shown in Fig. 5. At this time, the pin 12 moves towards the second end of the oval opening 13. Thereby, the second arm 7B of the lever 7 drops. At this time, the second arm 7B of the lever 7 is in a low position, and the first arm 7A is in a high position conversely. The first arm 7A contacts the upper stop portion 17A of the link rod and pulls up the link rod 17. At this time, the link rod 17 is in a high position and the fixing system 2 is locked, so the seat post 1 is fixed at a predetermined position inside the seat tube 20.
[0051] The possibility of tilting the saddle 18 rearward towards the inverted position shown in Fig. 5 is optional. This possibility has the advantage that in the case of a folding bicycle as described in European Patent No. 3634842, the saddle is tilted rearward so that the size of the folded bicycle is as small as possible. See Fig. 7B of European Patent No. 3634842. In such a case, due to the fact that the fixing system 2 is locked when the saddle 18 is in the inverted position (Fig. 5), the user can, if desired, hold the saddle 18 of the folded bicycle and operate this bicycle. This also enables the transportation of the folded bicycle without the risk of the seat post 1 coming out of the seat tube 20.
[0052] Pin 12 and oval opening 13 are an example of an operating system for moving lever 7. Other operating systems are also conceivable. For example, in certain embodiments (not shown), sheet support 10 supports a cam. This cam rotates around first axis 11 by the rotation of sheet support 10 around first axis 11. The second arm 7B of lever 7 is pressed against the outer contour of the cam. At this time, the second arm 7B is used as a cam follower. The rotation of the cam around the first axis 11 enables the up and down movement of the second arm 7B of the lever 7.
[0053] Another example of the fixing system 2 is shown in FIGS. 6 to 9. This system can be used instead of the fixing systems shown in FIGS. 1 and 2. The fixing system 2 includes a lower cone 32 connected to the lower end 17B of the link rod 17, an upper cone 33 fastened to the lower end 1B of the seat post 1, and a plurality of wedges 34 circumferentially arranged around the link rod 17 between the cones 32, 33. The vertices of the lower and upper cones face each other.
[0054] When the link rod 17 moves from its lower position to its upper position, the lower cone and the upper cone approach each other, and the link rod 17 pulls up the lower cone 32 so as to clamp the wedge 34 therebetween. As a result, the wedge 34 moves radially away from the link rod 17. Then, the wedge 34 presses the inner wall of the seat tube 20. Due to the resulting friction, the sliding of the seat post 1 inside the seat tube 20 is prevented, and thus the seat post 1 is fixed in place.
[0055] In some embodiments, as shown in FIGS. 6 to 9, the upper cone 33 is provided with a hole at its center for sliding the link rod 17.
[0056] The lower cone 32 and the upper cone 33 each have inclined surfaces 32A and 33B whose overall shape is conical. Each wedge 34 is angled at its upper and lower parts along the inclined surfaces 34A, 34B.
[0057] These wedges 34 can be held together around the link rod 17 by an elastic ring 35 surrounding the wedges 34. For this purpose, a groove 37 for receiving the ring 35 can be provided on the outer surface of the wedge 34.
[0058] In the unlocking position (FIG. 8) where the link rod 17 is in the lower position (corresponding to FIG. 4), the elastic ring 35 holds the wedges 34 close to the link rod 17, so that the seat post 1 can slide freely inside the seat tube 20.
[0059] When locked (FIG. 9), when the link rod 17 moves from the lower position to the higher position (as shown in FIGS. 3 and 5), the lower cone 32 approaches the upper cone 33. Under the action that the inclined surfaces 32A and 33B press against the inclined surfaces 34A and 34B respectively, the wedge 34 moves radially away from the link rod 17 (that is, in a direction perpendicular to the axis of the link rod 17) and is pressed against the inner wall of the seat tube 20. Due to the resulting friction, the sliding of the seat post 1 inside the seat tube 20 is prevented, and thus the seat post 1 is fixed at a predetermined position.
[0060] The outer surface of the wedge 34 can have a substantially the same radius of curvature as the inner wall of the seat tube 20 in the radial plane so as to maximize friction.
[0061] The presence of the groove 37 on the outer surface of the wedge 34 enables avoidance or limitation of the frictional force in the elastic ring 35. Thereby, the wear of the elastic ring 35 is reduced.
[0062] Each embodiment described in this disclosure is provided for illustration rather than limitation, and those skilled in the art may modify these embodiments or consider other embodiments while staying within the scope of the present invention in light of this disclosure.
[0063] In particular, those skilled in the art will easily be able to imagine modified examples that include only some of the features of the above-described embodiments, provided that some of these features are sufficient to achieve one of the advantages of the present invention. In addition, the various features of these embodiments may be used alone or in combination with each other. When combining the various features, these features may be combined as described above or otherwise. The present invention is not limited to the specific combinations described in this disclosure. In particular, unless otherwise specified, the features described with respect to one embodiment may equally apply to another embodiment.
Claims
1. It is a seatpost assembly, A seatpost (1) adapted to be mounted in a manner that allows it to slide inside the seat tube (20), A link rod (17) extending inside the seat post (1), the link rod (17) being movable between a lower position and a higher position relative to the seat post (1), A base (6) is attached to the upper end (1A) of the seat post (1), A seat support (10) on which a saddle (18) can be mounted, the seat support (10) being attached to the base (6), A fixing system (2) which is operable between an unlocked position in which the fixing system (2) does not prevent the sliding of the seat post (1) inside the seat tube (20) and a locked position in which the fixing system (2) prevents the sliding and fixes the seat post (1) to a predetermined position inside the seat tube (20), Equipped with, The fixing system (2) is operated by the movement of the link rod (17) between its high position and its low position. The seat support (10) is mounted on the base (6) in a manner that allows it to rotate around a first axis (11), and is connected to the link rod (17) such that the link rod (17) moves between its high position and low position as the seat support (10) rotates around the first axis (11). Seatpost assembly.
2. A seatpost assembly according to claim 1, wherein the seat support (10) is connected to the link rod (17) by a lever (7) attached to the base (6) in a manner that allows it to pivot around a second axis (8), the first arm (7A) of the lever (7) extends to one side of the second axis (8) and is connected to the link rod (17) so as to move the link rod (17) between its high and low positions, and the second arm (7B) of the lever (7) extends to the other side of the second axis (8) and rotates around the second axis (8) by the rotation of the seat support (10) around the first axis (11), Seatpost assembly.
3. A seatpost assembly according to claim 2, wherein the seat support (10) supports a pin (12), the second arm (7B) of the lever (7) is provided with an oval opening (13), the oval opening (13) and the seat support (10) are configured such that the pin (12) moves within and along the oval opening (13) while the seat support (10) rotates around the first axis (11), and the movement of the pin (12) within the oval opening (13) causes the lever (7) to pivot around the second axis (8).
4. A seatpost assembly according to claim 3, wherein the pin (12) traces a circular trajectory while the seat support (10) rotates around the first axis (11), the oval opening (13) is curved in the same direction as the circular trajectory, and the curvature of the oval opening (13) is smaller than the curvature of the circular trajectory of the pin (12).
5. A seatpost assembly according to claim 2, wherein the seat support (10) supports a cam that rotates around the first axis (11) by the rotation of the seat support (10) around the first axis (11), and the second arm (7B) of the lever (7) is pressed against the outer contour of the cam.
6. A seatpost assembly according to any one of claims 2 to 5, wherein the upper end (17A) of the link rod (17) passes through the first arm (7A) of the lever (7), and has an upper stopper (27A) and a lower stopper (27B) on both sides of the first arm (7A), and the first arm (7A) contacts the upper stopper (27A) when the link rod (17) is in the high position, and contacts the lower stopper (27B) when the link rod (17) is in the low position.
7. A seatpost assembly according to any one of claims 1 to 5, wherein the fixing system (2) is in the locked position when the link rod (17) is in the high position, and in the unlocked position when the link rod (17) is in the low position.
8. A seatpost assembly according to claim 7, wherein the seat support (10) is movable between a support position, an inverted position, an intermediate position between the support position and the inverted position, where the seat support (10) is tilted backward from the base (6), and where the seat support (10) is correctly facing upward and supported on the base (6), and where the seat support (10) is correctly facing upward and supported on the base (6), The link rod (17) is in the high position when the seat support (10) is in the support position, in the low position when the seat support (10) is in the intermediate position, and again in the high position when the seat support (10) is in the reversed position, in a seat post assembly.
9. A seatpost assembly according to any one of claims 1 to 5, wherein the fixing system (2) comprises: a lower cone (32) connected to the lower end (17B) of the link rod (17); an upper cone (33) mounted on the lower end (1B) of the seatpost (1), wherein the apex of the lower cone and the upper cone are opposite to each other; and a plurality of wedges (34) circumferentially arranged around the link rod (17) between the lower cone and the upper cone (32, 33), wherein when the link rod (17) moves from its lower position to its higher position, the link rod (17) pulls up the lower cone (32), the lower and upper cones move closer to each other, and the plurality of wedges move radially away from the link rod (17) by tightening the wedges (34) between the lower and upper cones.
10. A seatpost assembly according to any one of claims 1 to 5, wherein the lower end (1B) of the seatpost (1) is beveled along an inclined surface (31) that forms a non-zero angle with respect to a plane perpendicular to the main axis (X) of the seatpost (1), and the fixing system (2) comprises a wedge (30) having an inclined surface (30A) opposite to the inclined surface (31), and when the link rod (17) moves from its lower position to its higher position, the link rod (17) is pulled up by the wedge (30) and the inclined surface (30A) is pressed against the inclined surface (22) and slides, causing the wedge (2) to shift away from the main axis (X) of the seatpost (1).
11. A vehicle comprising: a seatpost assembly according to any one of claims 1 to 5; a frame having a seat tube (20) on which the seatpost (1) is mounted in a manner that allows it to slide within the frame; and a saddle (18) mounted on the seat support (10).