Multi-Arm Notching Spring for Reliable Timepiece Bezel Indexing
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Solution Overview
Problem
Existing notching systems for timepiece bezels suffer from issues of compactness, reliability, and the potential for premature wear due to independent arm deformations, which affect the number and durability of notches.
Innovation Solution
A notching spring with at least two elastic arms forming a closed loop, each with first notching teeth and a pivot connection element, designed to be convex when unloaded, and capable of increasing curvature when loaded, providing a reliable and compact notching system with a large number of notches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single elastic arm with notching element is used (as in EP 0 686 897), then the device complexity is reduced, but the reliability and durability of the notching system deteriorates due to independent arm deformations and premature wear
Solution Approach 1:
The spring is divided into multiple elastic arms (at least two) that are connected together to form a closed loop structure. Each arm can deform independently during operation, but they are mechanically coupled through the closed loop configuration. This segmentation allows each arm to handle localized stresses separately, preventing premature wear from propagating through the entire system and improving overall reliability while maintaining manageable complexity.
Solution Approach 2:
Multiple elastic arms are merged into a single closed loop structure that functions as one integrated notching system. The arms are connected in series to form a continuous loop that engages with the notching ring teeth simultaneously, distributing the mechanical load across multiple contact points and improving durability through balanced force distribution.
2Reliability
If multiple elastic arms are used to improve reliability, then the device complexity increases, but the compactness of the notching system may be compromised
Solution Approach 1:
The multiple elastic arms are arranged in a nested configuration where they overlap and interlock to form a compact closed loop structure. The arms are positioned concentrically around the rotation axis, with each arm nested within the spatial envelope defined by the others, minimizing the overall volume occupied by the spring while maintaining the multiple-arm configuration for improved reliability.
3Manufacturing precision
If the elastic arms deform independently, then the manufacturing precision is easier to achieve, but the balanced mechanical interaction and durability are reduced
Solution Approach 1:
The closed loop structure of the spring arms is pre-configured during manufacturing with predetermined geometric relationships and connection points. This preliminary arrangement ensures that when the notching system operates, the arms deform in a coordinated manner that distributes forces evenly across all arms and their connection points, preventing localized stress concentration and extending the durability of the stationary notching ring.
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 enhances the reliability and compactness of notching systems, allowing for a varied and large number of notches while ensuring balanced mechanical interactions, thus improving the durability and functionality of timepiece bezels.
Implementation Method 1
the elastic deformation of a given elastic arm is independent of the deformation of the elastic arms that adjoin it... the spring is made to bend, causing a reduction in the radius of curvature of each of the arms
Data Source
AI summary
A notching system (100) including a spring (1) having a first toothset including n first teeth (11a, 12a) a first member (2) having a second toothset including m second teeth (22a, 22b), and a second member (3) mounted so as to be movable, in particular mounted so as to be rotatable, with respect to the first member (2), the first and second toothsets being arranged such that, through their interactions, they define p notches or indexed positions, the spring (1) including at least two elastic arms (11, 12), and at least one first pivot connection element (1b) between said two elastic arms (11, 12), the second member including at least one second pivot connection element (3b) cooperating with the at least one first pivot connection element (1b) in order to create at least one pivot connection between the spring (1) and the second member (3).