Anti-trip Balance Spring Finger Channel Constraint
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Solution Overview
Problem
Existing anti-trip mechanisms for mechanical watches disturb the inertia of the balance and generate friction, limiting their efficiency and effectiveness in preventing excessive angular extension of the balance in both directions of rotation.
Innovation Solution
A balance spring with a finger integrally mounted on one of its coils, which moves within a travel limiter channel in the anti-trip mechanism, limiting the balance's angular travel without contacting the channel during normal operation, thus preventing excessive rotation in both directions without affecting the balance's inertia or efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pinion meshing with a toothed wheel is used to limit balance rotation, then the balance's angular extension is limited, but the inertia of the balance is disturbed and friction is generated
Solution Approach 1:
The invention extracts the anti-trip function from the balance assembly and places it in the flange as a separate component. The finger carried by the balance spring interacts with a corresponding channel in the flange to provide anti-trip functionality, eliminating the need for pinions and toothed wheels that generate friction and disturb inertia.
Solution Approach 2:
The finger acts as an intermediary element between the balance spring and the flange. It transmits the rotational motion of the balance spring while being constrained by the channel in the flange to prevent excessive angular extension, thereby providing anti-trip protection without direct mechanical interference.
2Reliability
If a locking arm inserted between a finger and columns is used to limit balance rotation, then excessive expansion is limited in one direction, but rotation in both directions cannot be limited
Solution Approach 1:
The channel in the flange is designed with an asymmetric geometry that allows the finger to move freely during normal oscillation in one direction while providing constraint during excessive rotation in either direction. The asymmetric shape of the channel enables bidirectional anti-trip protection while maintaining smooth operation during normal function.
3Reliability
If a pin stopped in a spiral groove is used to limit oscillation, then excessive oscillation is limited, but friction causes interference throughout oscillations
Solution Approach 1:
The invention replaces the traditional mechanical stop-and-friction system with a guidance-based system. The finger follows the contour of the channel in the flange during normal operation, eliminating contact friction. The channel's geometry provides the limiting function through shape constraint rather than mechanical stopping, thereby eliminating frictional interference.
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 effectively limits the balance's angular travel in both directions without disturbing its inertia or generating friction, ensuring efficient operation and preventing excessive rotation during shocks or accelerations.
Implementation Method 1
a balance spring with at least one blade or strip wound into a plurality of coils
Implementation Method 2
at least one said coil of said balance spring carries or includes at least one finger, mounted integrally with said at least one coil
Data Source
AI summary
An anti-trip mechanism includes a flange with a radial travel limiting channel and a balance spring with a strip wound into a plurality of coils. The balance spring includes an inner coil fixed, at a first end, to a collet coaxial to the balance spring relative to a pivot axis, and an outer coil fixed, at a second, opposite end, to a hooking element. A coil of the balance spring includes a finger that includes a feeler spindle stud that is mounted integrally with the coil. The feeler spindle stud is moveable without any contact, during the normal extension and contraction of said balance spring, in the radial travel limiting channel of the flange. The radial travel limiting channel limits travel of the finger relative to the pivot axis when an angle of pivoting imparted to the collet is greater than a determined nominal value.