Chronograph Counter Mechanism With Elastic Retrograde Reset
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Solution Overview
Problem
Existing chronograph mechanisms are complex, require delicate setup, and are uncomfortable to use due to high force requirements for reset, often bulky, and lack ease of arrangement on a timepiece dial.
Innovation Solution
A chronograph mechanism with a display mobile that includes teeth meshing with return mobiles, allowing temporary decoupling and retrograde movement for simplified construction, combined with neutralization devices for comfortable manipulation and efficient counter resetting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional chronograph mechanisms are used with multiple mobile components (clutch device, lock/brake, reset device, shuttle/column-wheel), then the measurement function is achieved, but the device complexity increases significantly and setup becomes delicate and complex
Solution Approach 1:
The patent combines multiple separate mobile components (clutch device, lock/brake, reset device, shuttle/column-wheel) into a single integrated return mobile structure. The return mobile performs multiple functions: it locks the display mobile during operation, controls the reset mechanism, and manages the elastic return member. This consolidation reduces the number of separate components while maintaining the chronograph measurement function.
Solution Approach 2:
The return mobile is designed as a multi-functional component that serves several purposes simultaneously: it acts as a clutch mechanism to engage/disengage the display mobile, functions as a lock during operation, controls the reset sequence, and manages the elastic return member. This multi-functionality eliminates the need for separate dedicated components for each function.
2Ease of operation
If conventional reset devices with heart-shaped cam and hammer are used, then the display mobile can be reset to zero position, but high force is required which is uncomfortable for the user
Solution Approach 1:
The patent introduces an intermediary elastic return member that mediates between the return mobile and the display mobile during reset operation. Instead of directly applying high force through a hammer mechanism, the elastic return member stores and releases energy gradually, reducing the peak force required by the user while still achieving the reset function.
Solution Approach 2:
The patent changes the force parameter by using an elastic return member that provides a progressive, controlled force profile during reset. The elastic member allows the reset force to be applied over a longer duration with lower peak values, transforming the force characteristics from high-impact to gradual, thereby improving user comfort.
3Adaptability or versatility
If conventional chronograph mechanisms with multiple counters (seconds, minutes, hours) are used, then comprehensive time measurement is achieved, but the mechanism becomes bulky in thickness direction
Solution Approach 1:
The patent implements a nested arrangement where multiple counter mechanisms (seconds, minutes, hours) are positioned concentrically or in overlapping layers. The display mobiles of different counters share common mechanical pathways and the return mobile structure, allowing comprehensive time measurement capability while minimizing the overall thickness of the mechanism.
Solution Approach 2:
The patent transitions from a planar arrangement of counters to a three-dimensional concentric or layered configuration. By utilizing the radial and vertical dimensions more efficiently, multiple counters can coexist in a compact space, reducing the thickness requirement while maintaining full time measurement versatility.
4Reliability
If conventional chronograph mechanisms are used, then the chronograph counter can be locked and reset, but delicate setting up and adjustment operations are required to ensure correct operation
Solution Approach 1:
The patent incorporates preliminary action features where the return mobile is pre-configured with predetermined engagement points and travel paths. The elastic return member is pre-loaded to specific tensions, and the toothed wheel geometries are designed with built-in indexing features. These preliminary configurations ensure that when the mechanism is assembled, the synchronization of locking, resetting, and counting functions occurs automatically without requiring delicate field adjustments.
Solution Approach 2:
The mechanism is designed to self-regulate and self-synchronize through the inherent mechanical properties of the return mobile and elastic return member. The elastic member automatically compensates for minor manufacturing tolerances, and the toothed engagement provides self-indexing that ensures correct positioning without requiring external adjustment operations during setup.
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 mechanism ensures robust and reliable operation with comfortable user interaction, reducing setup complexity and bulkiness, while maintaining efficient counter operation.
Implementation Method 1
an elastic return member arranged to act on the return mobile and to tend to return it to its initial position
Data Source
AI summary
The invention relates to a chronograph mechanism (1; 201), for a timepiece movement, including a counter for a unit of time comprising:—a display wheel capable of being rotated from a zero position,—a return wheel, rotatable between an initial position, associated with the zero position of the display wheel, and a final position, the display wheel and the return wheel being arranged such that the return wheel pivots from its initial position to its final position when the display wheel makes one revolution,—a resilient return member (20) arranged to act on the return wheel and to tend to return it to its initial position, the display wheel including a toothing arranged in mesh with the return wheel and having a truncated portion intended to allow the display wheel and the return wheel to be uncoupled on each complete revolution of the display wheel.