Carousel Cage Speed Control for Watch Escapement Drive
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Solution Overview
Problem
Existing mechanical watch movements with carousels lack the aesthetic appeal of tourbillons while being easier to produce and compensate for balance wheel faults, but they typically rotate at a speed that prevents the escapement wheel from being driven if the second wheel and cage rotate at the same speed.
Innovation Solution
A watch movement where the carousel cage rotates at one revolution per minute, allowing the balance wheel and escapement to operate at standard frequencies, enabling the carousel to carry a seconds indicator and maintain aesthetic appeal similar to a tourbillon.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the second wheel and cage rotate at the same speed, then the carousel structure is simplified, but the escapement wheel cannot be driven
Solution Approach 1:
The patent applies dynamics by making the cage rotate at a different speed than the second wheel. The cage completes one revolution per minute while the second wheel rotates at a different speed, creating relative motion between them. This dynamic speed difference enables the escapement wheel to be driven by the intermediate mobile, resolving the contradiction between structural simplification and functional reliability.
2Shape
If the carousel rotates at standard speed, then aesthetic appeal similar to tourbillon is achieved, but balance wheel frequency must be reduced
Solution Approach 1:
The patent segments the functions by separating the aesthetic display function (cage rotating at one revolution per minute visible on dial side) from the timekeeping function (balance wheel and escapement operating at standard frequencies). The intermediate mobile acts as an independent segment that transmits power while allowing the cage to rotate at display speed without affecting balance wheel frequency, resolving the contradiction between aesthetics and performance.
3Shape
If the cage is visible on the dial side, then aesthetic appeal is improved, but the mechanism becomes more complex
Solution Approach 1:
The patent applies multi-functionality by designing the cage to serve dual purposes: it acts as a structural support for the balance wheel and escapement, and simultaneously serves as a visible seconds indicator when positioned on the dial side. The intermediate mobile also performs multiple functions by transmitting power while enabling independent rotation speeds. This reduces overall mechanism complexity despite the aesthetic requirement.
Data Source
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AI summary
The movement has a balance and a gear-train for transmitting the energy stored in a barrel to an escapement wheel. The gear-train has an intermediate wheel (23) kinematically connected to the barrel by a portion of the gear and kinematically connected to the escapement wheel by another portion of the gear. The latter portion and the balance are mounted in a rotary cage (16) kinematically connected to the movement and coaxially rotated about the intermediate wheel at a speed different from speed of the intermediate wheel. The movement imposes speed of one revolution per minute to the cage.