Footring Height Adjustment Using a Tapered Collet Lock
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing footring adjustment mechanisms lack a reliable and efficient method for vertical height adjustment that provides secure locking and easy sliding functionality.
Innovation Solution
A mechanism featuring a collet sleeve with a radially outwardly projecting pin and a track on the hub, where the track has first and second pin stops, and at least one surface is tapered, allowing the hub to compress or retract the collet sleeve onto a shaft for locking or releasing, enabling frictional locking and sliding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a footring adjustment mechanism uses a cam or threaded hub design, then the vertical height can be adjusted, but the locking reliability and ease of operation are insufficient
Solution Approach 1:
The mechanism uses a dynamic collet sleeve that can transition between expanded and contracted states. When the hub is rotated, the pin moves along the tapered surface, causing the collet sleeve to dynamically change its grip force on the shaft, providing both easy adjustment and reliable locking
Solution Approach 2:
The tapered surface on the collet sleeve or hub converts rotational motion into axial motion, changing the dimensional parameter of the collet sleeve (its expanded or contracted state). This parameter change enables the transition between locked and adjustable positions with simple rotational input
2Reliability
If the collet sleeve is compressed onto the shaft to lock the position, then the locking reliability improves, but the device complexity increases
Solution Approach 1:
The mechanism merges multiple functions into the hub component: it serves as both the adjustment element (through rotation) and the actuation mechanism (through the pin-track-taper interaction). This integration reduces the number of separate components needed to achieve reliable locking
Solution Approach 2:
The tapered surface automatically converts the rotational motion of the hub into the axial compression of the collet sleeve without requiring additional actuators or mechanisms. The system self-regulates the compression force based on the geometry of the tapered surface, reducing the need for external control systems
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
This mechanism securely locks the vertical position of the footring while allowing easy adjustment by compressing or releasing the collet sleeve, providing a reliable and user-friendly height adjustment solution.
Implementation Method 1
compress the collet sleeve onto the shaft to frictionally lock the collet sleeve to the shaft
Data Source
AI summary
A mechanism for vertically adjusting a component on a shaft has a collet sleeve riding on the shaft. A spiral track of the component's hub receives a radially outwardly projecting pin on the collet sleeve. The outer surface of the collet sleeve and the inner surface of the hub are tapered so that the hub can rotated one direction to advance the hub on the collet sleeve and compress the collet sleeve onto the shaft to frictionally lock the collet sleeve to the shaft. Because the hub is joined to the collet sleeve by the pin, this also locks the vertical position of the component. Conversely, the hub can be oppositely rotated to release the compression of the collet sleeve so that the collet sleeve, and therefore the vertical component, is slidable on the shaft.