Instantaneous Date Control Device for Mechanical Wristwatch
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Solution Overview
Problem
Existing instantaneous date control mechanisms for horological date displays face issues such as torque capture from the horological movement, risk of double jumps, inability to manually correct time or date without restrictions, and suboptimal part trajectories, leading to potential damage and compromised chronometric performance.
Innovation Solution
An instantaneous date control device with a yoke mobile featuring a pivot axis eccentrically placed on a second toothed wheel, allowing the unlocking and driving yoke to pivot and position the driving finger optimally for date disc jumps, while incorporating a biasing spring for secure date disc protection and enabling manual corrections without restrictions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a manual correction mechanism is added to allow unrestricted time and date setting, then ease of operation is improved, but device complexity increases due to additional components and control mechanisms
Solution Approach 1:
The crown is designed to perform multiple functions: normal time setting, rapid date correction, and protection against prohibited manual correction periods. By making the existing crown multi-functional rather than adding separate mechanisms, the patent improves ease of operation while minimizing additional complexity
Solution Approach 2:
The mechanism automatically detects the prohibited manual correction period through the interaction between the cam, control lever, and actuating lever, and prevents manual correction during this period without requiring additional sensors or control systems. The mechanical design itself provides the protective function
2Speed
If the date disc is made lightweight for instantaneous jump, then speed is improved, but reliability deteriorates due to risk of double jumps and potential damage from uncontrolled movement
Solution Approach 1:
The actuating lever is positioned and prepared in advance during the prohibited manual correction period, so that when the permitted period begins, the instantaneous jump can occur immediately without delay. This preliminary positioning ensures reliable single-jump operation
Solution Approach 2:
The cam and control lever act as intermediary elements that mediate between the horological movement and the date disc. They control the timing and execution of the instantaneous jump, preventing uncontrolled movement and double jumps while enabling rapid date change
3Manufacturing precision
If the driving lever trajectory is optimized for precision, then manufacturing precision is improved, but device complexity increases due to complex guiding mechanisms
Solution Approach 1:
The pivot axis is placed eccentrically on the second toothed wheel rather than at its center. This eccentric positioning in a different dimensional location allows the driving lever to achieve an optimized trajectory for precise date disc engagement without requiring complex guiding mechanisms
Solution Approach 2:
The asymmetric placement of the pivot axis relative to the toothed wheel creates the necessary trajectory variation. This asymmetric geometry naturally guides the driving lever through the optimal path for precise operation while simplifying the overall mechanism
4Power
If torque capture from horological movement is maximized for reliable date change, then power is improved, but chronometric performance deteriorates due to excessive load on the movement
Solution Approach 1:
The cam is designed to distribute torque capture periodically throughout the day rather than concentrating it in a single moment. The cam profile and control lever interaction create a rhythm of torque application that accumulates sufficient power for the instantaneous jump while spreading the load over time to protect chronometric performance
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 solution minimizes torque capture from the horological movement, prevents double jumps, allows for unrestricted manual date and time corrections, and optimizes part trajectories, ensuring safe, reliable, and user-friendly operation, suitable for extra-thin movements.
Implementation Method 1
said unlocking and driving yoke (4.3) comprises a biasing spring (4.6) exerting a biasing force on said driving finger (4.5)
Data Source
AI summary
An instantaneous date control device for a timepiece, in particular for a mechanical wristwatch, including: a date disc, a gear train forming a kinematic linkage between the control device and a horological movement of said timepiece, a first mobile including a first toothed wheel driven at a speed of one turn per day and a cam mounted freely rotatably, over a limited angular range and/or in a single direction of rotation, as well as temporarily coupled in rotation to said first toothed wheel, a second mobile including a second toothed wheel driven at a speed of one turn per day, an unlocking and driving yoke carrying a feeler bearing on said cam and a driving finger which can mesh with teeth located on the date disc, an unlocking and driving spring, and a retaining means allowing to secure the angular position of the date disc between two instantaneous jumps.