Cam Locking Mechanism for Tubular Saddle Posts
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing locking devices for tubes, such as those on bicycles between the saddle post and saddle tube, fail to effectively prevent slippage under varying forces, leading to instability and potential movement when forces are exerted along the longitudinal axis.
Innovation Solution
A locking device with a cam system and a rod that moves inside the first tube, featuring cams that pivot to exert pressure on the inside face of the second tube, preventing sliding when activated, and a return spring to maintain contact, ensuring secure locking in both downward and upward forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rod and cam system is used to lock the first tube to the second tube, then the locking effectiveness is improved, but the device complexity increases
Solution Approach 1:
The cam system employs dynamic elements that can pivot between locked and unlocked positions. The cams are mounted on pivot pins allowing them to rotate into contact with or away from the second tube, providing adaptive locking that responds to applied forces while maintaining mechanical simplicity
Solution Approach 2:
The locking mechanism is divided into discrete functional elements: the rod for actuation, multiple cams for locking engagement, and pivot pins for movement. This segmentation allows each component to perform its specific function efficiently while enabling easy assembly and maintenance
2Stability of the object's composition
If the cam system exerts pressure on the inside face of the second tube to prevent sliding, then the stability is improved, but the friction and resistance increase
Solution Approach 1:
The cams utilize curved surfaces that contact the inside face of the second tube. This curvature distributes the locking force more evenly and allows for smoother engagement and disengagement, reducing peak friction forces while maintaining stable locking when engaged
Solution Approach 2:
The cam system operates in periodic cycles of engagement and disengagement. During normal operation, the cams remain in a stable locked position; when unlocking is required, the rod actuates the cams to pivot away, creating a periodic action that reduces continuous friction while maintaining stability during locked operation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively prevents slippage between the saddle post and saddle tube by accentuating contact pressure, ensuring stability during sitting and lifting, thereby enhancing the locking mechanism's effectiveness.
Implementation Method 1
each of the cams exerts pressure on the inside face of the second tube and prevents the first tube from sliding inside the second tube
Implementation Method 2
a repositioning system configured to return said cams into their second position
Data Source
AI summary
The invention relates to a locking device (5) for locking together a first tube (2) and a second tube (3), the first tube being slidably received in the second tube, the locking device comprising at least one rod (10) mounted to move into two positions and a cam system made up of at least two cams (6, 7, 8, 9) that are mounted on the first tube to pivot either into a first position in which the cams are not in contact with the second tube and allow the first tube to slide inside the second tube, or into a second position in which each of the cams exerts pressure on the inside face of the second tube and prevents the first tube from sliding inside the second tube. The rod is assembled with the cam system and is configured so that it at least moves the cams into their first position, a repositioning system being configured to return said cams into their second position. The invention also relates to a bicycle (1) equipped with such a locking device (5) arranged between a saddle post (2) and a saddle tube (3).