Retrograde Watch Movement Asymmetric Hour Ring Correction
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Solution Overview
Problem
Existing watch movement mechanisms combining retrograde and jumping displays are complex and cumbersome, particularly in correcting time, as they require significant size and complexity to facilitate bidirectional corrections.
Innovation Solution
A watch movement mechanism featuring a retrograde mobile with asymmetrical internal teeth, a drive member that transmits clockwise corrections to the hour ring while preventing counterclockwise transmissions, allowing for bidirectional correction of the retrograde display without full revolution, thus simplifying the construction and enabling rapid time setting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a correction mechanism allows bidirectional correction of the retrograde display, then the time setting becomes faster and more convenient, but the mechanism size and complexity increase significantly
Solution Approach 1:
The patent employs an asymmetric internal toothing on the hour ring with differently inclined flanks (first flank and second flank). The drive member is configured to engage with specific flanks depending on the correction direction. This asymmetric design allows the mechanism to transmit corrections in the clockwise direction while blocking counterclockwise corrections, thereby enabling bidirectional correction capability without requiring a fully symmetric complex mechanism for both directions.
Solution Approach 2:
The drive member acts as an intermediary element between the correction mechanism and the hour ring. It selectively transmits rotational movements from the retrograde mobile to the hour ring based on the direction of correction. The drive member's specific geometry and engagement characteristics with the asymmetric toothing allow it to mediate the transmission of corrections only in the clockwise direction, simplifying the overall mechanism by eliminating the need for separate transmission paths for each direction.
2Reliability
If the correction mechanism transmits corrections in both directions to the hour ring, then all corrections are synchronized, but the mechanism requires modification of the jumping hour drive which increases complexity
Solution Approach 1:
The asymmetric internal toothing of the hour ring with its specifically inclined flanks creates a one-way transmission path. The drive member is designed to engage with the first flank for clockwise corrections, transmitting them to the hour ring, while the second flank's inclination prevents engagement during counterclockwise corrections. This asymmetric configuration allows selective transmission without modifying the existing jumping hour drive mechanism, maintaining its original simplicity while achieving synchronized correction when needed.
3Adaptability or versatility
If the mechanism allows unlimited counterclockwise correction of the retrograde mobile, then correction flexibility increases, but accidental movements of the jumping hour ring may occur
Solution Approach 1:
The asymmetric internal toothing design with differently inclined flanks inherently blocks the transmission of counterclockwise corrections to the hour ring. The drive member's engagement geometry with the second flank prevents any rotational transmission in the counterclockwise direction, thereby eliminating the risk of accidental hour ring movements while allowing unlimited counterclockwise correction of the retrograde mobile. This asymmetric configuration provides built-in protection against display errors.
Solution Approach 2:
The correction mechanism is segmented into independent functional zones: the retrograde mobile can be corrected bidirectionally without affecting the hour ring, while the hour ring receives corrections only in the clockwise direction. This segmentation isolates the two display elements, allowing flexible correction of the retrograde indicator while protecting the jumping hour display from unintended movements, thereby maintaining both flexibility and reliability.
Data Source
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AI summary
The invention relates to a watch movement comprising a retrograde moving part, an hour ring having an internal asymmetric toothing and driven by the retrograde moving part so as to display the current time in a jumping manner, a correction mechanism allowing the retrograde moving part to be corrected in a two-directional manner, and a driving body which is actuated by said correction mechanism and engaged with said internal asymmetric toothing such that the corrections of the retrograde moving part in the clockwise direction are transmitted to the hour ring, while the corrections in the anti-clockwise direction are not transmitted to the hour ring.