Bicycle Quick-Release Torque Limiting Mechanism
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Solution Overview
Problem
Existing quick-release systems for bicycles lack control over tightening force, which can lead to safety issues due to variability in tightening magnitude, reliance on user strength, and potential for excessive or insufficient tension, resulting in risks of loosening or breakage, and often require expensive high-strength materials or oversized components.
Innovation Solution
A quick-release system with a torque limiting mechanism that includes a disengageable connection interface formed by friction portions, an elastic tensioning mechanism, and a torsional stress recovery mechanism, allowing for controlled tightening and indication of optimal torque through audible signals, reducing material costs and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the skewer is made of high-strength material and oversized to guarantee resistance against failing under very high torques, then the resistance to failure is improved, but the weight and cost increase
Solution Approach 1:
The torque limiting mechanism performs preliminary action by preventing excessive torque from being applied to the skewer in the first place. The mechanism limits the maximum torque to a predetermined safe value, eliminating the need to design the skewer for worst-case failure scenarios and allowing use of lighter, less expensive materials.
Solution Approach 2:
The torque limiting mechanism acts as an intermediary between the user's tightening action and the skewer. It mediates the torque transmission, allowing the skewer to be designed for normal operating conditions rather than extreme failure conditions, thereby reducing weight and cost.
2Ease of operation
If the center distance is adjusted to be too long, then the tightening force is reduced, but the tightening becomes insufficient causing safety problems
Solution Approach 1:
The torque limiting mechanism provides feedback by mechanically limiting the maximum torque that can be applied, regardless of user adjustment. This feedback loop ensures that even if the center distance is adjusted incorrectly, the tightening force cannot exceed safe limits, thereby improving reliability while maintaining ease of adjustment.
3Ease of operation
If the center distance is adjusted to be too short, then the tightening force is increased, but the axial tension force on the skewer becomes too substantial causing rupture or breakage
Solution Approach 1:
The torque limiting mechanism performs preliminary protection by preventing excessive torque application before it can damage the skewer. This preliminary action allows the skewer to be designed with lower strength requirements, as the mechanism ensures torque never exceeds safe thresholds during operation.
4Ease of manufacture
If the tightening force is not controlled, then the device is easier to manufacture, but the tightening magnitude varies substantially causing loosening or breakage
Solution Approach 1:
The torque limiting mechanism is designed to be self-regulating, automatically limiting torque to predetermined values without requiring complex external control systems. This self-service approach maintains manufacturing simplicity while ensuring consistent, reliable tightening across all operations.
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 system provides consistent and controlled tightening force, reduces the risk of loosening, and allows for lightweight construction using lower-cost materials, enhancing user safety and efficiency while minimizing material costs.
Implementation Method 1
at least one of the friction portions is disengageable against the action of an elastic tensioning mechanism
Implementation Method 2
The connection interface is formed by engagement of two friction portions in contact with one another
Data Source
AI summary
A quick-release system for a quick-release device, in particular for a cycle, such as a bicycle, the device being of the type including an axially extending skewer and an end support element mounted on a first end of the skewer adapted to be supported on a first tightening surface of the cycle. The quick-release system includes a tightening sub-assembly including a support surface and an actuation sub-assembly including a movable actuating mechanism, capable of axial rotation around the skewer and configured to transmit a tightening torque to the tightening sub-assembly when the device is being tightened. The system includes tightening torque limiting mechanism making it possible to limit the torque transmitted by the actuation sub-assembly to the tightening sub-assembly.