Balance Spring Length Adjustment for Gravity-Compensated Isochronism
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Solution Overview
Problem
Existing manual adjustment mechanisms for the active length of a balance spring in mechanical oscillators are prone to frequency variations due to gravity, leading to inaccuracies in watch rate, and require tedious manual adjustments.
Innovation Solution
An autonomous adjustment device for the active length of a balance spring, utilizing a spherical weight that rotates based on gravity to move arms between rest and correction positions, adjusting the balance spring length to compensate for gravitational perturbations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual adjustment mechanisms are used to adjust the active length of the balance spring, then the frequency can be adjusted, but gravity influences the frequency depending on the orientation of the watch movement
Solution Approach 1:
The device enables autonomous self-adjustment of the balance spring active length by utilizing the spherical weight's gravity-dependent position to automatically modify the regulator's position, allowing the system to compensate for gravitational effects on its own without external intervention
Solution Approach 2:
The spherical weight's position, determined by gravity and orientation, provides continuous feedback that automatically adjusts the regulator position to compensate for gravitational perturbations, creating a closed-loop system that responds to changing conditions
2Manufacturing precision
If manual adjustment is performed by a watchmaker using clamping means, then the active length can be modified, but the precision of adjustment is significantly limited and the process is tedious
Solution Approach 1:
The autonomous adjustment device eliminates the need for manual watchmaker intervention by automatically adjusting the balance spring active length through the gravity-driven spherical weight mechanism, saving time and achieving higher precision
Solution Approach 2:
The device replaces static manual adjustment with dynamic autonomous adjustment, where the regulator position continuously adapts to gravitational effects through the movable spherical weight, enabling precise real-time compensation
3Adaptability or versatility
If the balance spring moves between pins due to play, then the active length changes, but this causes disturbance in frequency
Solution Approach 1:
The device autonomously compensates for position variations and play in the balance spring-pins interface by automatically adjusting the active length through the regulator mechanism, maintaining frequency stability without external intervention
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 device provides precise, autonomous compensation for gravitational perturbations, ensuring consistent isochronism of the balance wheel by continuously adjusting the active length of the balance spring.
Implementation Method 1
a spherical weight, mobile in rotation around two axes perpendicular to each other, the weight being arranged to move according to gravity
Implementation Method 2
elastic constraint means configured to exert an elastic restoring action in the rest position on the arms
Data Source
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AI summary
The present invention relates to a device (6) for autonomous adjustment of the active length of a balance spring (5), for a balance-spring type oscillator (4, 5), comprising a cock (12) mounted on a plate (13) of a watch movement (2) and in which a balance shaft pivots, the balance spring (5) having an inner end fixed to the balance shaft and an outer end fixed to a stud (8) attached to a stud holder (10), the stud holder (10) being pivotally mounted on the cock (12) concentrically with the balance shaft, and means for modifying the active length of the balance spring (5).