Bicycle Seat Post Anti-Twist Spline Mechanism
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Solution Overview
Problem
Existing bicycle seat post devices with anti-twist protection require precise manufacturing tolerances to minimize rotation play, leading to high production costs and complexity.
Innovation Solution
The use of a spline device with a clamping element and guiding groove configuration that allows for adjustable anti-twist protection, enabling reliable anti-rotation without the need for tight tolerances, by pressing the clamping element and spline unit together, particularly in the extended position to compensate for rotation play.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If clamping elements and guiding grooves are manufactured with highly precise fit to eliminate rotation play, then anti-twist protection reliability is improved, but manufacturing costs and complexity increase
Solution Approach 1:
The invention changes the geometric parameters of the guiding groove to have a trapezoidal cross-section with a wider opening at the top than at the bottom. This parameter change allows the clamping element to be securely held without requiring high-precision manufacturing tolerances, as the tapered geometry provides self-centering and anti-rotation functionality through its shape rather than through precise dimensional tolerances.
Solution Approach 2:
The guiding groove exhibits local quality variation through its trapezoidal profile, where the cross-sectional dimensions change along the length of the groove. The wider top section accommodates the clamping element with sufficient clearance to prevent rotation, while the narrower bottom section provides stable support. This local variation in geometry eliminates the need for uniform high-precision manufacturing throughout the entire groove.
2Manufacturing precision
If clamping elements and guiding grooves are manufactured with highly precise fit to eliminate rotation play, then rotation play is reduced, but production costs increase
Solution Approach 1:
The guiding groove is designed with a trapezoidal cross-section where the opening width at the top exceeds the width at the bottom, creating a tapered geometry. This parameter change allows standard manufacturing tolerances to be used while still achieving the functional requirement of preventing rotation play, as the geometric taper provides self-alignment and secure retention of the clamping element.
3Reliability
If multiple clamping elements are used to prevent saddle rotation, then anti-twist protection is improved, but device complexity increases
Solution Approach 1:
The single clamping element is equipped with a multi-faceted geometry that interacts with the trapezoidal guiding groove to provide comprehensive anti-rotation protection. The local quality of the clamping element's contact surfaces is optimized to engage with the tapered walls of the groove, creating multiple constraint points that prevent saddle rotation without requiring multiple separate clamping elements.
Data Source
AI summary
A bicycle component for an at least partially muscle-powered bicycle, including a seat post device adjustable between two positions, with two support members telescopically movable relative to one another in the axial direction namely, a first support member and a second support member. The bicycle component has an anti-twist protection with a clamping element that non-rotatably couples the support members together, and which is displaceably received in a guiding groove, so that rotational movement of the first support member relative to the second support member can be at least partially blocked. The anti-twist protection includes a spline device with a spline unit that can be pressed against the clamping element in the axial direction. By pressing the clamping element and the spline unit together, the clamping element can be moved relative to the guiding groove transverse to the axial direction.