Balance Spring Length Adjustment for Gravity-Stable Watch Oscillation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing manual adjustment mechanisms for balance spring length in mechanical watches are prone to frequency variations due to gravity, leading to imprecise adjustments and disturbances in the balance wheel's oscillations, particularly when the watch is positioned vertically or horizontally.
Innovation Solution
An autonomous adjustment device for the balance spring length, utilizing a freely rotating weight interacting with movable arms and cams to modify the spring length based on gravity, with damping mechanisms to stabilize adjustments during sudden movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a manual adjustment mechanism with pins is used to adjust the balance spring length, then the device structure is simple, but gravity causes frequency variations and the adjustment precision is limited
Solution Approach 1:
The weight automatically positions itself according to gravity direction, causing the cam to rotate and adjust the balance spring length without manual intervention. The system uses gravity itself as the driving force for autonomous adjustment, eliminating the need for manual operation while achieving precise compensation for gravitational effects on timekeeping accuracy.
Solution Approach 2:
The patent replaces the manual mechanical adjustment system with an autonomous system driven by gravity. The weight-cam mechanism automatically converts gravitational force into rotational motion that precisely adjusts the balance spring length, substituting human-operated mechanical adjustment with a self-regulating gravitational mechanism.
2Adaptability or versatility
If the balance spring moves between pins due to play, then the mechanism allows adjustment, but it causes disturbance in active length and frequency variation
Solution Approach 1:
The patent removes the pins from the adjustment mechanism and replaces them with a cam surface. The cam directly contacts the balance spring to adjust its length, eliminating the play and instability caused by pin-based adjustment while maintaining the ability to precisely control the spring's active length.
Solution Approach 2:
Instead of having the balance spring move between fixed pins, the invention uses a rotating cam to actively push and position the balance spring. This inverts the interaction: rather than the spring finding its position between pins, the cam deterministically sets the spring's position through controlled contact, eliminating play and improving stability.
3Manufacturing precision
If a clamping system is used to secure the balance spring, then the spring can be adjusted, but the adjustment process is tedious and requires multiple manual steps
Solution Approach 1:
The weight-cam mechanism autonomously performs the entire adjustment process by utilizing gravity to rotate the cam, which continuously adjusts the balance spring length. This eliminates the need for watchmakers to manually loosen clamps, adjust the spring, and retighten components, transforming a multi-step manual process into a self-executing automatic system.
Solution Approach 2:
The patent replaces the manual clamp-based adjustment system with a gravity-driven cam mechanism. The cam's rotating surface directly controls the balance spring length through continuous contact, substituting the discrete manual clamping operation with a smooth, automatic mechanical system that requires no human intervention.
4Adaptability or versatility
If the watch is positioned vertically or horizontally, then gravity affects the balance wheel oscillations, but manual adjustment cannot compensate for position-dependent variations
Solution Approach 1:
The weight is free to rotate and dynamically repositions itself according to the watch's orientation relative to gravity. As the watch changes position, gravity causes the weight to rotate to a new equilibrium position, which automatically adjusts the cam and modifies the balance spring length to compensate for gravitational effects, maintaining frequency consistency across different orientations.
Solution Approach 2:
The system uses gravity itself as feedback: the weight's position is determined by the direction of gravitational force, and this position automatically translates into the appropriate adjustment of the balance spring length. The gravitational field provides continuous feedback about the watch's orientation, and the cam mechanism converts this feedback into real-time compensation, maintaining isochronism regardless of position.
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 gravity-induced perturbations in the balance wheel's isochronism, ensuring consistent oscillation frequency regardless of the watch's orientation.
Implementation Method 1
a movable weight rotating around a shaft on which at least one cam is mounted, the weight being arranged to rotate freely around the shaft according to gravity
Implementation Method 2
elastic constraint means configured to exert an elastic restoring action in position on the at least one arm
Implementation Method 3
damping means comprising a toothed wheel coaxial with and mounted on the weight, and a damping device arranged to cooperate with the weight via the toothed wheel and limit the change in the active length of the balance spring in the event of sudden acceleration or deceleration
Data Source
Figure 1~2
Figure 3~4
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).