Watch Bezel with Segmented Elastic Ring for Independent Friction and Indexing
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Solution Overview
Problem
Existing watch cases with rotary bezels face challenges in optimizing frictional torque and indexing functions independently, often requiring large annular cross sections and affecting the bezel's centering and user experience, while also limiting the ratio of the glass diameter to the overall middle diameter.
Innovation Solution
A watch case design featuring a ring and middle with immobilizing elements and elastic components that separate friction and indexing functions, allowing independent adjustment of these functions within a small cross-sectional area, using a pivot connection and elastic elements to generate uniform friction and indexing torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single set of flexing leaves is used to both index and hold the bezel, then the device complexity is reduced, but the frictional torque cannot be optimized independently from the detent function
Solution Approach 1:
The single flexing leaf is divided into two separate flexing leaves: a first flexing leaf dedicated to the detent function (indexing) and a second flexing leaf dedicated to the braking function (frictional torque). This segmentation allows each leaf to be optimized independently for its specific function, resolving the contradiction between device simplicity and functional adaptability.
2Ease of operation
If the vertical position of the bezel is adjusted to regulate frictional torque, then the friction can be optimized, but the centering of the bezel is affected
Solution Approach 1:
The segmentation of functions into separate flexing leaves allows independent adjustment of frictional torque through the second flexing leaf without affecting the centering of the bezel, which is maintained by the first flexing leaf and the single set of projections.
Solution Approach 2:
The second flexing leaf acts as an intermediary element that provides frictional torque regulation independently of the centering mechanism. This intermediary allows adjustment of friction without influencing the precise centering of the bezel on the middle.
3Ease of operation
If ball bearings and helical springs are used to center and hold the bezel, then the frictional torque becomes uniform and adjustable, but the annular cross section becomes too large to accommodate the detent function
Solution Approach 1:
The complex ball bearing and helical spring mechanism is replaced by a simpler elastic ring structure that provides the same centering and frictional torque functions. This extraction of the essential function (elastic force) from the complex mechanism reduces the annular cross section while maintaining uniform and adjustable frictional torque.
Solution Approach 2:
The elastic ring acts as a flexible element that provides centering and frictional torque with a much smaller cross section than rigid ball bearings and springs. The flexibility of the elastic ring allows it to deform and provide the necessary forces within a compact annular space.
4Reliability
If multiple bending operations are performed on the ring to create flexing leaves, then the detent function is achieved, but the sensation when turning the bezel becomes dependent on handling and axial pressure distribution
Solution Approach 1:
By separating the detent function and braking function into distinct flexing leaves, each optimized for its specific purpose, the system provides more consistent and predictable operation. The first flexing leaf ensures reliable indexing while the second flexing leaf provides uniform frictional torque, reducing dependence on user handling variations.
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
Enables independent adjustment of bezel friction and indexing functions, maintaining a small cross-sectional area and maximizing the glass diameter ratio, while improving user experience by separating the functions and allowing for a more optimized bezel operation.
Implementation Method 1
a first elastic element (4b, 4c, 4d) pressing the bezel against the middle in such a way as to create friction between the middle and the bezel
Implementation Method 2
allowing the bezel to turn on the middle
Data Source
AI summary
A watch case (9; 19; 29) has a middle (2; 12; 22), a bezel (3; 13; 23) mounted to turn on the middle, a ring (5; 15; 25) interfacing between the middle and the bezel, and a first indexing element (1; 11) and a second indexing element (3a; 13a; 23a) which collaborate in such a way as to index the bezel in position relative to the middle, a first elastic element (4b, 4c, 4d; 15; 25) pressing the bezel against the middle and a second elastic element (4a) pressing the first indexing element against the second indexing element (3a; 13a; 23a), the ring comprising an opening (5a; 15a) through which the first or the second indexing element is arranged.