Hybrid Gear Timepiece Control with Elastomeric Roller
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Solution Overview
Problem
Existing control systems for rotating flanges in timepieces are either too large due to deep toothing, noisy due to tooth interaction, and inconvenient for fine adjustments, or have low reliability and efficiency due to friction-driven mechanisms.
Innovation Solution
A hybrid gear device using a drive roller made of elastomeric material for rolling friction transmission between a crown and a flange, eliminating the need for deep toothing and reducing noise, while maintaining reliability and allowing for easier positioning and assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a terminal pinion with deep toothing is used to ensure latching between the crown and flange, then the transmission reliability is improved, but the overall height of the timepiece increases
Solution Approach 1:
The patent introduces a crown stone as an intermediary element between the crown and flange. This crown stone has a crowned face that engages with the flange's peripheral bead, while the crown itself engages with the crown stone. This intermediary allows the use of shallower toothing while maintaining reliable transmission, thereby reducing the overall height of the timepiece.
Solution Approach 2:
The patent replaces the traditional direct tooth-to-tooth meshing system with a hybrid system combining friction-based crown stone engagement and rolling element engagement. The crowned face of the crown stone works in conjunction with a rolling element (crown wheel) to transmit motion, substituting the need for deep toothing while maintaining transmission reliability.
2Reliability
If deep toothing is used to ensure latching, then the transmission reliability is improved, but the gear mechanism becomes noisy
Solution Approach 1:
The patent replaces the noisy tooth-to-tooth meshing system with a hybrid system that incorporates a crowned face engagement and rolling element engagement. The rolling element (crown wheel) rolling on the crowned face of the crown stone provides smooth, quiet operation while maintaining reliable transmission, eliminating the rattling and clicking noises associated with traditional deep toothing systems.
3Device complexity
If a small diameter terminal pinion is used, then the device complexity is reduced, but the manufacturing precision becomes difficult to achieve
Solution Approach 1:
The crown stone acts as an intermediary that distributes the engagement requirements across larger, more easily manufactured surfaces. The crowned face of the crown stone and the peripheral bead of the flange provide large contact areas that are much easier to machine with high precision than small diameter pinion toothing, thereby reducing manufacturing difficulty while maintaining device functionality.
4Device complexity
If a friction drive mechanism is used, then the device complexity is reduced, but the transmission reliability deteriorates over time
Solution Approach 1:
The patent employs a composite engagement system combining different mechanical principles: the crowned face engagement (similar to friction drive but with geometric constraint) and the rolling element engagement. This hybrid approach maintains the simplicity of the friction drive while adding the reliability of positive mechanical engagement, preventing the transmission reliability deterioration that occurs with pure friction drive mechanisms over time.
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 hybrid gear device reduces the overall height of the timepiece, enhances transmission quality and reliability, and reduces production costs by simplifying machining and material usage, while providing a silent and efficient rotational control mechanism.
Implementation Method 1
A hybrid gear device using a drive roller made of elastomeric material for rolling friction transmission between a crown and a flange
Implementation Method 2
the flexibility of which avoids jerks and the noise of rattling gears
Data Source
Figure 1A~1C
Figure 2A~2C
Figure 3A~3C
AI summary
The invention relates to a control system for a rotating member of a timepiece, including a control member for actuating said rotating member, and a transmission device between said control member and said rotating member. The control system is characterised in that the gear device is a hybrid gear device including a first element which can move about a first axis of rotation (10) and is provided with a drive roller (25) made of an elastomer material, and a second element (31) which can move about a second axis of rotation (30) and is provided with a toothed gearing (32). The drive roller (25) engages with the toothed gearing (32) by means of friction.