Lifting seat tube for a bicycle

Abstract

The utility model provides a bicycle lifting seat tube, including outer tube, inner tube, bush, sealing assembly and buffer ring. Inner tube can move up and down in the outer tube, and bush is equipped between inner and outer tube, and top end has upper abutting part. Sealing assembly is equipped between inner and outer tube, has annular inner ring shoulder, effectively blocks liquid and solid material to enter seat tube inside, keeps clean. Buffer ring is equipped between sealing assembly inner ring shoulder and bush upper abutting part, absorbs impact and vibration in the process of lifting, reduces the wear and tear between inner tube and bush, disperses reaction force, reduces stress concentration, improves durability and impact resistance, and keeps stable cooperation, avoids shaking and abnormal sound, ensures that lifting is smooth and comfortable. The utility model effectively solves the problems, such as seat tube subsidence, shaking, abnormal sound and wear and tear, improves stability and durability, and improves riding experience.

Description

Technical Field

[0001] This utility model relates to bicycle seatposts, and more particularly to a dropper seatpost for bicycles. Background Technology

[0002] The saddle height of a bicycle affects riding comfort and safety. Therefore, current bicycle designs incorporate adjustable seatposts that can adjust the saddle height according to the rider's body type, habits, and riding environment, allowing the rider to ride in the correct posture and thus improving riding comfort and safety.

[0003] However, while adjustable seatposts can lower the inner tube height to save storage space, the height must be readjusted every time the seatpost is lowered, requiring time to find a suitable seat height. This can cause inconvenience and trouble for riders.

[0004] According to publication number M613821, a bicycle dropper seatpost includes a bushing structure. This bushing can be composed of two parts, and the assembly method is not limited to a fitting or fixed connection, nor does it need to be distinguished as an upper and lower bushing. The main function of this structure is to assist the inner tube in sliding stably within the seatpost cylinder and to achieve height adjustment positioning through a limiting structure. However, this design has significant deficiencies in its stress management mechanism, which may lead to structural damage and performance degradation under long-term use.

[0005] Specifically, when a user adjusts the height of the seat post, the limiting protrusion on the inner tube contacts the height limiting groove of the bushing body, generating a direct force. This force, without effective buffering, is rapidly concentrated and transmitted to localized areas of the bushing structure, especially the contact or connection areas between components. Because the bushing body lacks stress absorption or dispersion structures, such as elastic components, energy transfer structures, or structural transition designs, stress concentration occurs at these points under repeated stress. Over long-term use, this can lead not only to localized wear, deformation, and cracks, but also to loosening or detachment of the bushing components, severely impacting the normal raising and lowering operation of the seat post and structural stability.

[0006] Furthermore, the bushing, as the transition interface between the seatpost and the inner tube, also serves to reduce friction, prevent wobbling, and stabilize the guide. If stress concentration causes a decrease in bushing precision, it can further lead to jamming, wobbling, or abnormal noise during seatpost raising and lowering, affecting the rider's riding experience and accelerating wear on other structural components. Therefore, while this design achieves basic raising and lowering and limiting functions, there is still significant room for improvement in long-term durability and structural reliability.

[0007] In summary, optimizing the stress transmission path in the bushing structure and introducing structural designs with buffering, shock absorption, or stress dispersion functions, such as flexible inserts, elastic gaskets, or multi-segment stress relief structures, will help reduce the risk of localized stress concentration, improve overall service life and performance stability, and thus improve the reliability and user experience of the lifting seat tube in practical applications. Utility Model Content

[0008] The purpose of this invention is to provide an improved bicycle dropper seatpost to overcome the shortcomings of existing technologies in terms of stress transfer and distribution design. Traditional dropper seatposts often suffer from stress concentration in specific areas of the bushing components due to the direct bearing of the inner tube's reaction force by the limiting structure. This leads to localized wear, deformation, or damage, affecting the smoothness of seatpost lifting and lowering, the stability of the overall structure, and even shortening the product's service life.

[0009] To address the aforementioned issues, this invention proposes a bushing structure with no limitation on assembly form. Its design emphasizes the introduction of stress buffering and dispersion mechanisms, allowing the reaction force generated by the inner tube under stress to be absorbed and evenly dispersed through a specific structure, preventing damage from excessive stress on a single part over a long period. Therefore, it not only effectively improves the durability and structural integrity of the bushing body but also ensures stable and smooth operation of the lifting seat post during use, further enhancing the user's riding experience and the overall value of the product.

[0010] To achieve the above objectives, the present invention provides a bicycle dropper seatpost, comprising an outer tube; an inner tube that is vertically and horizontally displaceable and passes through the outer tube, with the top end of the inner tube located outside the outer tube and the bottom end located inside the outer tube; a bushing having an upper ring portion and a lower ring portion disposed between the inner tube and the outer tube, the top end of the bushing having an upper abutment portion; a sealing assembly for sealing the space between the inner tube and the outer tube to prevent liquid or solid substances from entering the seatpost; the sealing assembly having an annular inwardly oriented inner shoulder; and a buffer ring installed between the inner shoulder of the sealing assembly and the upper abutment portion of the bushing.

[0011] In this bicycle dropper seatpost, a shock ring is positioned between the upper abutment of the bushing and the inner shoulder of the sealing assembly. Its primary function is to absorb the impact and vibration generated during the raising and lowering of the inner tube, reducing direct friction and wear between the inner tube and the bushing. The shock ring's elastic structure effectively disperses and mitigates reaction forces, reducing stress concentration and thus improving the seatpost system's impact resistance and durability. Furthermore, the shock ring helps maintain a stable fit between the inner tube and the bushing, preventing wobbling or abnormal noise caused by vibration, ensuring a smooth and comfortable raising and lowering process. The sealing assembly, located between the inner and outer tubes, effectively prevents liquids and solids from entering the seatpost, keeping the interior clean, preventing contamination and corrosion, and ensuring the long-term stability and reliable operation of the overall structure.

[0012] Optionally, the outer tube has a first outer tube section and is provided with multiple turning slots. These turning slots are arranged around the first outer tube section, which can make the inner tube more stable during height adjustment, prevent the inner tube from moving or shifting during the adjustment process, thereby improving the overall structural stability and making the height adjustment operation simpler and more accurate.

[0013] Optionally, the outer tube has a second outer tube portion connected to the first outer tube portion. The second outer tube portion is provided with a plurality of first alignment portions, which are disposed on the inner wall of the second outer tube portion. Therefore, they can be precisely aligned with the corresponding parts of the bushing, ensuring that the bushing will not slip or misalign during the engagement with the outer tube, thereby improving the stability of the inner tube and its ability to make precise adjustments.

[0014] Optionally, the bushing is provided with a second alignment part that aligns with the first alignment part of the second outer tube. The design of the second alignment part matches the first alignment part, thus making the fit between the bushing and the outer tube tighter and more stable, thereby preventing the bushing from shaking during operation and ensuring the structural accuracy and safety of the entire lifting seat tube system.

[0015] Optionally, the outer diameter of the upper ring is greater than or equal to the outer diameter of the lower ring, thus forming a strong fitting structure between the upper and lower rings, thereby improving the joint strength between the two rings. This can effectively prevent misalignment or detachment between the upper and lower rings during adjustment, thereby improving the overall structural stability and impact resistance of the lifting seat tube.

[0016] Optionally, the bushing comprises an upper sleeve body and a lower sleeve body, the upper sleeve body comprising an upper ring portion and the lower sleeve body comprising a lower ring portion. This design enables the bushing to achieve greater structural stability, thereby improving the durability of the entire system and allowing for simple replacement or maintenance as needed, extending the service life of the lifting seat tube.

[0017] Optionally, the outer circumferential surface of the inner tube is provided with a height control part, and the lower part of the bushing is provided with a height limit part. After the inner tube rises, the height control part of the inner tube can abut against the height limit part of the bushing. The height limit part is used to limit the maximum range of movement of the inner tube to prevent the inner tube from being damaged due to excessive movement, thereby ensuring the long-term stable operation of the product.

[0018] Optionally, the height limiting part has multiple stepped height limiting grooves arranged along the axial direction of the inner tube. These height limiting grooves are arranged along the axial direction of the inner tube at a certain interval. After the inner tube rises, the height controlling part of the inner tube can abut against one of the height limiting grooves of the bushing. Therefore, the lower sleeve can accurately align with one of the height limiting grooves during the height adjustment process, thereby limiting the maximum movement range of the inner tube, effectively preventing the inner tube from being damaged due to excessive movement, and ensuring the long-term stable operation of the product.

[0019] Optionally, the top edge of the lower ring of the lower sleeve is in close contact with the bottom edge of the upper ring of the upper sleeve, thus ensuring precise fit between the two components during adjustment and avoiding gaps or instability between them during operation, thereby improving the stability and durability of the overall structure.

[0020] Optionally, the lifting seat tube further includes a buffer ring disposed between the top edge of the lower ring portion of the lower sleeve and the bottom edge of the upper ring portion of the upper sleeve. Through the elastic buffering effect of the buffer ring, the impact and vibration generated during adjustment between the upper and lower sleeves can be effectively absorbed, reducing direct friction and wear between them, improving the durability and stability of the structure, and preventing loosening or abnormal noise caused by long-term use, thereby ensuring smooth and comfortable operation of the lifting seat tube.

[0021] The detailed construction, features, assembly, or use of the dropper seatpost for bicycles will be described in the following specific embodiments. However, it should be understood that the embodiments and accompanying drawings described below are for illustrative purposes only and should not be used to limit the scope of protection of this utility model. Attached Figure Description

[0022] Figure 1 This is a perspective view of the lifting seat tube according to a preferred embodiment of the present invention;

[0023] Figure 2 yes Figure 1 A partial exploded 3D view of the lifting seat tube;

[0024] Figure 3 This is a perspective view of the lifting seat tube of a preferred embodiment of the present invention from another direction;

[0025] Figure 4 yes Figure 3 A partial exploded 3D view of the lifting seat tube;

[0026] Figure 5 This is a partial cross-sectional view of a preferred embodiment of the lifting seat tube of this utility model, showing the state in which the bushing abuts against the height control part of the inner tube with the uppermost height limiting groove.

[0027] Figure 6 This is a partially enlarged cross-sectional view of the lifting seat tube according to a preferred embodiment of the present invention;

[0028] Figure 7 This is a perspective view of a preferred lifting seat tube of the present invention, omitting some components, showing the alignment status;

[0029] Figure 8 This is a three-dimensional sectional view of a preferred lifting seat tube of the present invention, showing the engaged state;

[0030] Figure 9 This is a partially enlarged cross-sectional view of the lifting seat tube of another preferred embodiment of the present invention.

[0031] In the accompanying drawings, the meanings of the reference numerals are as follows:

[0032] 10-Lifting seat post;

[0033] 12-Clamping seat;

[0034] 14-Gas bar;

[0035] 16-Flip-Flops;

[0036] 20-Outer tube;

[0037] 22-First Foreign Affairs Department;

[0038] 24-Second Foreign Affairs Department;

[0039] 26-Turn the card slot;

[0040] 28-First opposing part;

[0041] 30-Inner tube;

[0042] 32-Height control unit;

[0043] 40 - Sealing assembly;

[0044] 42-Cap;

[0045] 44-Inner shoulder;

[0046] 46 - Seals;

[0047] 50-Bushing;

[0048] 60 - Upper body;

[0049] 62 - Upper ring;

[0050] 64-Upper part;

[0051] 66-Turn the card forward;

[0052] 68-Second opposing part;

[0053] 70-Lower sleeve;

[0054] 72 - Lower ring;

[0055] 76 - Height Restriction Section;

[0056] 78-Height Restriction Trench;

[0057] 90-buffer ring. Detailed Implementation

[0058] First, it should be noted that the technical features provided by this utility model are not limited to the specific structures, uses, and applications described in the embodiments. The terms used in the description are all illustrative descriptive terms that can be understood by those skilled in the art. The directional descriptive terms such as "front," "upper," "lower," "rear," "left," "right," "top," "bottom," "inner," and "outer" mentioned in this specification are only illustrative descriptive terms based on the normal use direction and are not intended to limit the scope of protection.

[0059] To illustrate the technical features of this utility model in detail, the following embodiments are provided and described in conjunction with the accompanying drawings, wherein:

[0060] Please refer to the accompanying drawings. In a preferred embodiment of the present invention, the lifting seat tube 10 includes an outer tube 20, an inner tube 30, a sealing component 40, a bushing 50, and a buffer ring 90.

[0061] The outer tube 20 consists of a first outer tube section 22, a second outer tube section 24, multiple reversing slots 26, and a first alignment section 28. The first outer tube section 22 and the second outer tube section 24 are tightly connected by design. The reversing slots 26 are provided on the first outer tube section 22 to facilitate adjustment or fixation of the internal components. The first alignment section 28 is located on the second outer tube section 24 and is specifically designed to ensure accurate alignment during assembly. Notably, the inner diameter of the second outer tube section 24 is larger than the inner diameter of the first outer tube section 22. This design helps improve structural stability and ensures effective fit between components.

[0062] The top of the outer tube 20 has multiple reversing slots 26 (six arc-shaped slots are used as an example, but the number is not limited to this). The reversing slots 26 are arranged in a ring with equal intervals relative to the axis of the outer tube 20.

[0063] The top end of the inner tube 30 is located outside the outer tube 20 and is provided with a clamping seat 12 for mounting a seat cushion (not shown in the figure). The bottom end of the inner tube 30 passes through the top end of the outer tube 20 and is inserted into the outer tube 20. In addition, the outer peripheral surface of the bottom end of the inner tube 30 has three straight height control parts 32 (only at least one is actually needed), and the three height control parts 32 are arranged at equal intervals relative to the axis of the inner tube 30.

[0064] An air pressure bar 14 is installed inside both the outer tube 20 and the inner tube 30. A trigger 16 is installed at the bottom of the outer tube 20. When the trigger 16 is driven by the controller (not shown in the figure) to trigger the air pressure bar 14, the inner tube 30 can rise or fall relative to the outer tube 20. If the top of the inner tube 30 is not bearing the rider's weight, the inner tube 30 will rise relative to the outer tube 20. However, if the top of the inner tube 30 is bearing the rider's weight, the inner tube 30 will fall relative to the outer tube 20.

[0065] The sealing assembly 40 has a cap 42 and a seal 46. The cap 42 is screwed onto the top of the outer tube 20, and the seal 46 is fitted onto the inner tube 30 and pressed against the outer circumferential surface of the inner tube 30 by the cap 42, thereby filling the gap between the outer tube 20 and the inner tube 30. Furthermore, the inner circumferential surface of the cap 42 has an inner shoulder 44 located below the seal 46, the inner shoulder 44 being formed circumferentially inward. The sealing assembly 40 primarily covers the inner tube 30, isolating it from external dirt and preventing easy leakage of internal lubricating oil.

[0066] A bushing 50 is disposed between the outer tube 20 and the inner tube 30. The bushing 50 has an upper sleeve 60 and a lower sleeve 70. In this embodiment, the upper sleeve 60 is made of metal, and the lower sleeve 70 is made of a flexible material (e.g., plastic). The upper sleeve 60 and the lower sleeve 70 are designed as an integral structure, for example, bonded together by adhesive or plastic molding. Although the upper sleeve 60 and the lower sleeve 70 are an integral structure in this embodiment, in other embodiments they can be assembled in a separable manner, allowing for disassembly and reassembly according to maintenance needs. This design not only improves the durability of the system but also ensures flexibility when needed.

[0067] The upper sleeve 60 is rotatably mounted on the top of the outer tube 20. Structurally, the upper sleeve 60 includes an upper ring portion 62, an upper abutment portion 64, a reversing locking protrusion 66, and a second alignment portion 68. The upper abutment portion 64 is located above the upper ring portion 62 and integrally connected to it. The reversing locking protrusion 66 is located on the outer peripheral side, and the second alignment portion 68 is located on the top edge. Therefore, when the bushing 50 rotates, the reversing locking protrusion 66 of the upper sleeve 60 aligns with one of the reversing locking slots 26 of the outer tube 20, allowing the rider to control the rotation angle of the bushing 50 and improve adjustment accuracy.

[0068] The lower sleeve 70 is located inside the outer tube 20. Structurally, the lower sleeve 70 includes a lower ring portion 72 and a height limiting portion 76. The lower ring portion 72 is located at the top of the lower sleeve 70, and the height limiting portion 76 is located at the bottom of the lower sleeve 70. This allows the upper sleeve 60 and the lower sleeve 70 to rotate synchronously. Furthermore, the top edge of the lower ring portion 72 of the lower sleeve 70 is integrally connected to the bottom edge of the upper ring portion 62 of the upper sleeve 60 (but this invention is not limited to this, and it can also be a combined type). Furthermore, the bottom end of the lower sleeve 70 has three height-limiting portions 76 (in fact, at least one height-limiting portion 76 is sufficient). The height-limiting portions 76 are arranged in an evenly spaced ring relative to the axial direction of the outer tube 20 and are located above the three height-controlling portions 32 of the inner tube 30. Each height-limiting portion 76 is composed of five height-limiting grooves 78 arranged in a stepped manner along the axial direction of the outer tube 20. The lower sleeve 70 abuts against one height-controlling portion 32 of the inner tube 30 through one of the height-limiting grooves 78 to limit the height point of the inner tube 30 when it rises. That is, the bushing 50 abuts against the height-controlling portion 32 of the inner tube 30 through the height-limiting portion 76 of the lower sleeve 70. In addition, the outer diameter of the upper ring portion 62 of the upper sleeve 60 is greater than or equal to the outer diameter of the lower ring portion 72 of the lower sleeve 70 to improve structural strength.

[0069] Through the above-described structural design of the lifting seat tube 10, the top edge of the lower ring portion 72 of the lower sleeve 70 is connected to the bottom edge of the upper ring portion 62 of the upper sleeve 60. Therefore, when the inner tube 30 is adjusted to a desired height by the pneumatic rod 14, when the height control portion 32 of the inner tube 30 abuts against one of the height limiting grooves 78 of the height limiting portion 76 of the lower sleeve 70, the stress generated by the height control portion 32 can be transmitted through the top edge of the lower ring portion 72 to the bottom edge of the upper ring portion 62 of the upper sleeve 60, effectively dispersing the transmitted stress. This reduces the stress on the bushing 50 and gives the lifting seat tube 10 a longer service life.

[0070] If the lower sleeve 70 is combined with the upper sleeve 60 and is made of a flexible material (such as plastic), the lower sleeve 70 can be slightly elastically deformed under force, so the hardness of the upper sleeve 60 will be greater than that of the lower sleeve 70.

[0071] In this embodiment, the buffer ring 90 is an O-ring made of nitrile rubber (NBR) with high elasticity and high pressure resistance, and is positioned between the inner shoulder 44 of the sealing assembly 40 and the upper abutment 64 of the upper sleeve 60. The elastic design of the buffer ring 90 effectively absorbs and evenly distributes external impact forces, thereby reducing negative impacts on other critical components and further ensuring operational stability and long-term durability. This design helps reduce impact stress between the bushing 50 and the inner tube 30, reducing mechanical stress damage to the structure during operation, thus extending the service life of the lifting seat tube. This buffering mechanism enables stable operation in more challenging environments, improving overall performance and reliability.

[0072] This invention cleverly combines the buffer ring 90 and the outer tube 20, and includes multiple reversible slots 26 and a first alignment part 28. These features not only provide effective cushioning but also allow the user to easily align and ensure accurate engagement visually. In particular, the second alignment part 68 works in conjunction with the first alignment part 28 to facilitate visual alignment and ensure precise engagement, effectively preventing the buffer ring 90 from entering the grooves, avoiding potential damage or malfunction, and improving durability and stability.

[0073] In this embodiment, when the second alignment part 68 determines its specific position, the relative position of the first alignment part 28 is also determined. Therefore, the specific position of the reversing slot 26 can be inferred from the position of the first alignment part 28. Specifically, the reversing slot 26 is located circumferentially on the outer tube 20 and precisely corresponds to the reversing protrusion 66 of the bushing 50. Which reversing slot 26 the reversing protrusion 66 engages with can be determined by the first alignment part 28 and the second alignment part 68. This design ensures precise alignment of each component during rotation, avoiding deviations or misalignments, thereby improving overall stability and operational accuracy. Therefore, the key to this process is that once the second alignment part 68 determines its position, the accurate position of the first alignment part 28 can be calculated from that position, thus determining the position of the reversing slot 26. This series of correspondences ensures stability and functionality during rotation and effectively controls the precise fit between each component.

[0074] When the rotating slot 26 and the first alignment part 28 are spaced apart, this design helps ensure that the buffer ring 90 can stably and effectively perform its functions of absorbing shock and providing a seal. The buffer ring 90 is responsible for absorbing shock and preventing noise from metal-to-metal contact during the expansion and contraction of the inner tube; therefore, it requires an independent, undisturbed space for normal compression and rebound. If the rotating slot 26 and the first alignment part 28 are too close, the compression area of ​​the buffer ring 90 may overlap with the rotary positioning structure, causing installation difficulties, uneven stress, or deformation, thus affecting the sealing and shock absorption effects. By spaced them apart, the rotary positioning structure and the buffer structure are effectively separated, avoiding mutual interference. This not only improves the assembly accuracy and structural stability of the overall seat tube but also ensures that the buffer ring 90 maintains a normal compression state and long-term durability during use, further enhancing the operational smoothness and reliability of the overall structure.

[0075] Furthermore, to optimize the overall performance of the buffer ring 90 in the seat post system, particularly in its fit with the cap 42 and the upper abutment 64 of the bushing 50, this design emphasizes the integration and improvement of multiple structures and materials. Its main purpose is to enhance the positioning stability and sealing performance of the buffer ring 90, while also improving its durability and stress absorption capacity.

[0076] First, the internal structure of the cap 42 should be designed so that its lower end can accurately align with and tightly engage with the upper abutment 64 of the bushing 50, forming a clear structural positioning reference. This mating surface needs to have high flatness and smoothness to reduce the possibility of uneven compression or sealing failure caused by local gaps. The buffer ring 90 is disposed between the cap 42 and the upper abutment 64, forming a restricted compression zone in this space, achieving effective buffering and sealing functions through deformation under stress.

[0077] Under the downward pressure of the cap 42, the buffer ring 90 is forced to compress to the upper abutment 64 of the bushing 50. At this time, its elastic deformation provides a vertical shock absorption effect, while tightly fitting the contact surface between the two components to achieve a sealing effect. This structural design ensures that the buffer ring 90 will not displace or move during operation, and can repeatedly withstand cyclic stress, maintaining a stable buffering and sealing state.

[0078] To further enhance overall stability, the cap 42 and the upper abutment 64 can form an annular limiting groove on their mating surface, allowing the buffer ring 90 to be accurately embedded therein, preventing lateral sliding or rotation, and improving installation consistency. This groove structure also helps to disperse concentrated stress and reduce the risk of material fatigue caused by single-point loads.

[0079] In terms of materials, the buffer ring 90 can also be made of other materials with high elasticity and high pressure resistance, such as fluororubber (FKM) or thermoplastic elastomer (TPE), to ensure that it can maintain its shape and elasticity under high-frequency compression. The contact surfaces of the cap 42 and the bushing 50 are recommended to be made of anodized or surface-hardened metal to improve wear resistance and support, while preventing the uniformity of pressure on the buffer ring 90 from being affected by metal deformation.

[0080] In summary, the function of the buffer ring 90 is no longer limited to shock absorption and sealing, but forms a cohesive structural system with the cap 42 and the upper abutment 64 of the bushing 50. Through the joint design, material selection, and installation positioning control of the three components, it is ensured that the buffer ring 90 can produce stable and uniform deformation during compression, thereby improving the reliability and durability of the overall system.

[0081] like Figure 9The diagram shows another preferred embodiment of the lifting seat tube of this utility model, which is largely the same as the embodiment described above, except that it also includes another buffer ring 90. This buffer ring 90 is located between the top edge of the lower ring portion 72 of the lower sleeve 70 and the bottom edge of the upper ring portion 62 of the upper sleeve 60. Through the elastic buffering effect of this buffer ring 90, the impact and vibration between the upper sleeve 60 and the lower sleeve 70 can be effectively absorbed, reducing direct friction and wear between them, improving the durability and stability of the structure, preventing loosening and abnormal noise, and ensuring smooth and comfortable operation of the lifting seat tube. The upper sleeve 60 and the buffer ring 90 can be combined in various ways, and the buffer ring 90 and the lower sleeve 70 can be combined in various ways, or the upper sleeve 60 and the lower sleeve 70 can be combined in various ways with the buffer ring 90 placed between them, to adapt to different structural requirements and manufacturing processes, further improving the flexibility and reliability of the product.

[0082] In addition to the examples above, this utility model is not limited to bicycle dropper seats with a height limiting section for adjusting the overall height; it can also be applied to dropper seats without a height limiting groove.

[0083] Finally, it must be reiterated that the methods and components disclosed in the above embodiments of this utility model are merely illustrative examples and are not intended to limit the scope of protection of this utility model. Any simple structural modifications or changes made without exceeding the scope of this utility model, or substitutions with other equivalent components, should still fall within the scope of protection of this utility model.

Claims

1. A dropper seatpost for a bicycle, characterized in that, Includes: One outer tube; An inner tube is inserted into the outer tube and can be moved up and down. The top end of the inner tube is outside the outer tube and the bottom end is inside the outer tube. A bushing having an upper ring portion and a lower ring portion disposed between the inner tube and the outer tube, and an upper abutment portion provided at the top of the bushing; A sealing assembly for sealing the space between the inner tube and the outer tube to prevent liquid or solid substances from entering the interior of the seat tube; the sealing assembly has an annular inwardly facing inner shoulder; A buffer ring is installed between the inner shoulder of the sealing assembly and the upper abutment of the bushing.

2. The bicycle drop seat post according to claim 1, characterized in that, The outer tube has a first outer tube section and a plurality of reversing slots provided in the first outer tube section.

3. The bicycle dropper seatpost according to claim 2, characterized in that, The outer tube has a second outer tube section connected to the first outer tube section, and a plurality of first alignment sections provided in the second outer tube section.

4. The bicycle dropper seatpost according to claim 3, characterized in that, The bushing has a second alignment portion that aligns with the first alignment portion of the outer tube.

5. The bicycle dropper seatpost according to claim 1, characterized in that, The outer diameter of the upper ring portion of the bushing is greater than or equal to the outer diameter of the lower ring portion.

6. The bicycle dropper seatpost according to claim 1, characterized in that, The inner tube has a height control part on its outer circumference and a height limit part on its lower part. After the inner tube is raised, the height control part of the inner tube can abut against the height limit part of the bushing.

7. The bicycle dropper seatpost according to claim 6, characterized in that, The height limiting part of the bushing has multiple height limiting grooves arranged in a stepped manner along the axial direction of the inner tube. After the inner tube rises, the height controlling part of the inner tube can abut against one of the height limiting grooves of the bushing.

8. The bicycle dropper seatpost according to claim 1, characterized in that, The bushing is composed of an upper sleeve body and a lower sleeve body, the upper sleeve body including the upper ring portion and the lower sleeve body including the lower ring portion.

9. The bicycle drop seat post according to claim 8, characterized in that, The top edge of the lower ring of the lower sleeve is connected to the bottom edge of the upper ring of the upper sleeve.

10. The bicycle drop seat post according to claim 8, characterized in that, It also includes a buffer ring disposed between the top edge of the lower ring portion of the lower sleeve and the bottom edge of the upper ring portion of the upper sleeve.

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