Helical Cam Clamping Device for Ergonomic Adjustment
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Solution Overview
Problem
Existing clamping devices for adjusting the height of components like seat posts and steering columns are ergonomically challenged, requiring significant user effort and posing risks due to protruding levers, and are difficult to operate when the bicycle is already mounted.
Innovation Solution
A clamping device with a coaxial helical cam system and actuation axis perpendicular to the clamping axis, allowing for a longer actuation lever that reduces effort and minimizes protrusion, enabling easier operation and adjustment even when the bicycle is assembled.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the lever length is increased to reduce user effort, then the actuation force required decreases, but the lever protrudes too much from the collar creating safety risks
Solution Approach 1:
The actuation axis is repositioned from being parallel to the clamping axis to being perpendicular to it. This dimensional change allows the lever to rotate in a different plane, enabling a longer lever arm that provides mechanical advantage while the lever tip retracts closer to the collar body, reducing protrusion and safety hazards.
2Object-affected harmful factors
If the lever length is reduced to minimize protrusion and safety risks, then the harm factor decreases, but significant forces are imposed on a small bearing surface making tightening difficult
Solution Approach 1:
By changing the actuation axis orientation to perpendicular, the system gains leverage in a different dimensional direction. This allows the lever to be long enough to provide adequate mechanical advantage while its rotation path keeps the tip closer to the collar, simultaneously reducing required force and minimizing protrusion.
Solution Approach 2:
The clamping element is divided into two separable ends that can move independently relative to each other. This segmentation allows each end to be actuated by the lever through the helical cam mechanism, distributing the force application and reducing the stress concentration on any single bearing surface.
3Manufacturing precision
If a tool is used for pre-tightening with the screw head, then the tightening precision improves, but the device complexity increases and requires additional tools
Solution Approach 1:
The helical cam mechanism integrated into the lever provides automatic pre-tightening capability. As the lever rotates during normal operation, the helical cam profile automatically engages and applies controlled pre-load to the clamping element, eliminating the need for separate tool-based pre-tightening operations while maintaining precision.
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 reduces the effort required for tightening and loosening, enhances ergonomics by minimizing lever protrusion, and allows for intuitive height adjustments post-mounting, ensuring safer and more convenient operation.
Implementation Method 1
One of these ends is connected to one of the ends of the clamping element, or to an actuation means comprising at least one arm, one end of which is connected to one of the ends of the clamping element, via a helical cam
Implementation Method 2
The helical cam has a second face opposite the first face, constituting a helical bearing surface. Furthermore, the end of the arm connected to one of the ends of the clamping element has a face constituting a helical bearing surface symmetrical to, and intended to cooperate with, the helical bearing surface of the helical cam
Data Source
Figure 1~3
Figure 2A~2B
AI summary
The invention relates to a clamping device for clamping a stem in a tube. The device comprises a clamping element (2) to surround the element (1) to be clamped about a clamping axis (A), said clamping element having two ends (2a, 2b) that can be moved closer together in order to clamp the element (1) to be clamped, and a clamping means including an actuating means (4) rotatably mounted about an actuating axis (B) and a joining means (3) connecting the two ends (2a, 2b) of the clamping element (2). Said clamping means enables the two ends of the clamping element to be moved closer together in relation to the actuating axis, the actuating axis (B) not being parallel to the clamping axis (A). Furthermore, the actuating means (4) includes at least one arm (4a), one end of which is connected to one of the ends (2a, 2b) of the clamping element (2) via a helical cam (4b). Thus, the actuating means can be considerably long, which reduces the amount of actuation force required, while barely protruding or not protruding at all relative to the element to be clamped when in the clamping position, which reduces the risk of injuries.