Horological Limiting Device for Watch Oscillator Rate Control
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Solution Overview
Problem
Mechanical watches with tourbillons or karussels face challenges in maintaining chronometric precision across different positions, as existing technologies do not effectively limit the variation of the oscillator's rate during hand-setting, leading to inaccuracies in timekeeping.
Innovation Solution
A horological limiting device that stops the tourbillon or karussel carriage during hand-setting by using a control rod to engage a lifting finger, which radially moves a stop finger to block the oscillator, ensuring precise time adjustment to the nearest second and restarting the oscillator after setting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the tourbillon or karussel carriage is allowed to move freely during hand-setting, then the mechanism is simpler to manufacture, but the chronometric precision deteriorates due to rate variation in different positions
Solution Approach 1:
The patent introduces a control rod as an intermediary element that connects the winding/setting stem to the carriage stopping mechanism. This rod transmits the stopping command from the user's manual operation to the carriage, enabling precise rate limitation during hand-setting without requiring direct complex mechanical coupling between the stem and carriage stopping elements
Solution Approach 2:
The carriage is equipped with self-contained stopping means (stop finger and stop surface) that automatically engage when the control rod is actuated. The stopping mechanism is integral to the carriage structure, allowing it to self-regulate its position and maintain chronometric precision without requiring external continuous intervention
2Manufacturing precision
If a control rod is introduced to stop the carriage during hand-setting, then the chronometric precision is improved, but the device complexity increases
Solution Approach 1:
The control rod serves multiple functions: it transmits the stopping command during hand-setting, enables precise time adjustment to the nearest second, and facilitates restarting of the oscillator. This multi-functionality reduces the need for separate dedicated mechanisms for each operation, thereby limiting overall device complexity while achieving high time-setting precision
Solution Approach 2:
The patent combines the stopping means (stop finger, stop surface) with the carriage structure itself, merging the limiting function into the existing carriage assembly. This integration eliminates the need for separate stopping mechanisms and reduces overall device complexity while maintaining precise chronometric control
3Manufacturing precision
If the oscillator is stopped during hand-setting, then the time-setting accuracy is improved to the nearest second, but the duration of oscillator action is reduced
Solution Approach 1:
The oscillator stopping is applied periodically and temporarily only during the specific hand-setting operation, rather than continuously. The control rod enables the user to stop the oscillator precisely when needed for time adjustment, then restart it immediately after setting. This periodic, on-demand stopping maintains high time-setting accuracy while minimizing interruption to the oscillator's overall operation duration
Data Source
AI summary
A horological device including an oscillator of a watch and device for stopping this oscillator embedded in a carriage of a tourbillon or karussel, including a rod arranged to axially push a lifting finger into an active blocking position, against a first spring tending to recall same axially into a rest position in which it bears against a carriage wheel, which lifting finger includes a ramp radially repelling a stop finger against a second spring tending to radially distance same from the axis, which stop finger is remote from the axis when the lifting finger is in the rest position thereof, and, in the active blocking position of this lifting finger, the stop finger can interfere with a stop cam integral with a wheel set of the oscillator, in an angular position remote from the dead center position of the oscillator.