Clock Barrel Elastic Flange Overtorque Protection
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Solution Overview
Problem
Existing timepiece barrel systems face issues with overtorque during maximum winding, leading to fatigue and chronometric problems, and lack clear indication of full winding for manual winding, with sliding flanges causing torque variations and wear during aging tests.
Innovation Solution
A non-circular barrel drum and flexible flange system where the flange deforms to separate from the drum at a predetermined torque, allowing controlled clutch release and reducing stress on components, with a specific shape that enables the flange to disengage without rotating the drum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a fixed flange is used to maximize spring properties and number of turns, then the spring can store maximum energy, but overtorque is generated during maximum winding causing fatigue and chronometric problems
Solution Approach 1:
The flange is designed with elastic protrusions that can dynamically change their radial position based on applied torque. At normal operating torques, the protrusions maintain full contact with the drum for maximum energy transmission. When overtorque is detected, the protrusions radially shrink and disengage from the drum, automatically protecting the system from excessive stress while allowing the spring to continue winding.
Solution Approach 2:
The system changes the contact parameter between the flange and drum based on torque conditions. The protrusions transition from a contacting state (transmitting full torque) to a non-contacting state (limiting torque), thereby adapting the force transmission characteristics to prevent overtorque damage while maintaining efficient energy storage during normal operation.
2Reliability
If a sliding flange is used to prevent overtorque, then component reliability is improved, but torque variations occur during maximum winding and wear increases during aging tests
Solution Approach 1:
The flange is segmented into multiple protrusions distributed around its circumference. This segmentation allows progressive disengagement as torque increases, with each protrusion independently responding to torque conditions. The segmented design distributes wear across multiple contact points and reduces torque variation compared to a single sliding contact point, while maintaining reliable overtorque protection.
3Adaptability or versatility
If a sliding flange is used for automatic movements, then automatic winding is enabled, but the user cannot clearly detect when the barrel is fully wound during manual winding
Solution Approach 1:
The system uses tactile feedback changes analogous to color changes in visual systems. As the protrusions disengage from the drum during overtorque protection, the user experiences a noticeable change in winding resistance and tactile sensation. This provides clear feedback to the user that the barrel is fully wound, eliminating the ambiguity present in traditional sliding flange 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 solution allows direct control of clutch release torque, reduces overtorque-related stress, provides a clear sensation of maximum winding, and extends component lifespan by distributing stress evenly, applicable to various horological movements.
Implementation Method 1
at least one said protrusion of said sliding elastic flange is subjected to radial shrinkage when the torque applied to said sliding elastic flange is greater than a torque limit value
Data Source
Figure 1~5
Figure 6~8
AI summary
A barrel (1) comprising a spring (2) cooperating internally with a plug (4), externally with a track (6) of a drum (7) by means of a sliding elastic flange (8). Said track (6) and flange (8) are of non-circular shape, nested in the free state of said flange (8), and arranged to cause a protrusion (12) of said flange (8) to cooperate against a threshold (11) of said track (6) when the torque applied to said flange (8) is less than a torque limit value, and to allow a radial contraction of said protrusion (12) when said torque is greater than said limit value, to allow the passage of said protrusion (12) over said threshold (11) and to allow an angular stroke of said flange (8) under the effect of said torque until the next encounter between said threshold (11) and said protrusion (12).