Escapement Mechanism Direct Detent Rocker Unlocking
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Solution Overview
Problem
The existing timepiece escapement mechanisms experience imprecision in the start of the pulse communicated to the regulator due to a lengthy succession of actions required to unlock the escapement wheels, which affects the isochronism of the regulator, as the unlocking is controlled by a dynamic movement of the leaf spring and varies with the winding level of the drive member.
Innovation Solution
The escapement mechanism includes a detent rocker that directly cooperates with the escapement mobile to lock and unlock the escapement wheels, using input and output members like spouts to act alternately on the escapement wheel, and incorporates a single escapement wheel set with winding elements that cooperate like a gear to ensure precise locking and unlocking, reducing the reliance on the leaf spring's dynamic movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the detent rocker is controlled indirectly through the winding rocker and leaf spring to unlock the escapement wheels, then the unlocking mechanism can be simpler, but the timing precision of the pulse delivery to the regulator deteriorates
Solution Approach 1:
The patent extracts the unlocking function from the indirect control chain (detent rocker → winding rocker → leaf spring) and assigns it directly to the detent rocker through spout cooperation with the escapement mobile. This separation allows the detent rocker to control unlocking independently and directly, improving timing precision while maintaining mechanism simplicity.
Solution Approach 2:
The spout acts as an intermediary element between the detent rocker and the escapement mobile, enabling direct cooperation for locking and unlocking. This intermediary mechanism provides precise control of the unlocking instant without requiring the leaf spring to take up play, thereby improving pulse timing precision.
2Device complexity
If the leaf spring dynamically controls the winding rocker to unlock the escapement wheels, then the mechanism can use fewer components, but the unlocking force varies with winding level affecting isochronism
Solution Approach 1:
The patent extracts the unlocking control function from the leaf spring's dynamic movement and assigns it to the detent rocker through direct spout cooperation. This separates the energy storage function (leaf spring) from the unlocking control function (detent rocker), eliminating the variation in unlocking force with winding level and improving isochronism.
Solution Approach 2:
The detent rocker is positioned in advance by the limiting stop before unlocking occurs. This preliminary positioning ensures that the unlocking action happens at a precise, predetermined moment independent of the winding level, thereby maintaining consistent isochronism across different power reserve conditions.
3Ease of manufacture
If the leaf spring must take up play before driving the winding rocker for unlocking, then the mechanism can have simpler positioning, but the unlocking sequence becomes longer reducing precision
Solution Approach 1:
The patent extracts the play-take-up requirement from the unlocking sequence by establishing direct spout cooperation between the detent rocker and escapement mobile. This eliminates the intermediate step where the leaf spring must take up play, shortening the unlocking sequence and improving the precision of pulse delivery timing.
Solution Approach 2:
The direct spout cooperation mechanism allows the detent rocker to immediately unlock the escapement wheels without the intermediate delay of the leaf spring taking up play. This skipping of the play-take-up step reduces the overall unlocking sequence duration and improves timing precision.
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
This solution allows for precise timing of the pulse delivery to the regulator, improving isochronism by ensuring the leaf spring is free to provide energy at the appropriate time, and simplifies the assembly by eliminating the need for indexing two escapement wheels, while reducing friction and inertia.
Implementation Method 1
The leaf spring is fixed by its two ends to recesses or to pivot members, and its midpoint is kept aligned with said two ends. The distance separating the two recesses is such that the leaf spring undergoes a compression which forces it to deform according to a second mode buckling.
Implementation Method 2
The bistable elastic member is a leaf spring working in buckling. The leaf spring can occupy two stable states, the transition from one to the other of these stable states being effected by reversing the direction of the two convexities.
Data Source
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AI summary
The invention relates to a timepiece escapement comprising at least one escapement wheel (1), a bistable elastic member (2), a winding lever (3) arranged to be driven by said at least one escapement wheel (1) so as to wind the bistable elastic member (2) during winding phases, and a detent lever (4) arranged to be driven by a detent of said bistable elastic member (2) after each winding phase so as to transmit an impulse to a regulator. The at least one escapement wheel (1) is locked after each winding phase, and then released. The detent lever (4) is arranged to engage directly with the at least one escapement wheel (1) so as to lock said at least one escapement wheel (1).