Coup Perdu Escapement Adjustable Lost Strokes

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Solution Overview

Problem

Existing lost-stroke escapements, such as detent escapements, often compromise oscillation frequency and quality factor, limiting their application to high-quality oscillators and conventional ones alike, with few mechanisms offering more muted alternations effectively.

Innovation Solution

A direct escapement mechanism incorporating an escape wheel that directly supplies energy to a balance wheel, a blocking member to intermittently block rotation, and a trigger wheel system with an elastic pawl and release mechanism to control impulses, allowing adjustable lost strokes and optimized interactions between the escape wheel and balance wheel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If a detent escapement is used to limit disturbances to the oscillator and increase power reserve, then the power reserve is improved, but the oscillation frequency is reduced and the quality factor requirement becomes more stringent

Engineering Contradiction:
Improvepower reserveVSAvoidoscillation frequency
Core Design Contradiction:
Duration of action of moving objectVSSpeed

Solution Approach 1:

The escapement mechanism dynamically adjusts the blocking duration through the interaction between the escape wheel teeth and the blocking member, allowing the system to transition between blocked and unblocked states. This dynamic operation enables the balance wheel to maintain higher oscillation frequencies while still accumulating sufficient energy reserve, as the blocking is intermittent rather than continuous.

Inventive Principle:
Principle #15Dynamics

2Reliability

If a detent escapement is used to reduce disturbances to the oscillator, then the quality factor is improved, but the oscillation frequency is reduced

Engineering Contradiction:
Improvequality factorVSAvoidoscillation frequency
Core Design Contradiction:
ReliabilityVSSpeed

Solution Approach 1:

The escapement employs periodic blocking action where the blocking member intermittently engages with the escape wheel teeth. This periodic engagement allows the balance wheel to complete full oscillations with minimal disturbance during unblocked phases, maintaining high quality factor, while the timing and duration of blocked phases can be optimized to preserve oscillation frequency.

Inventive Principle:
Principle #19Periodic action

3Duration of action of moving object

If the number of lost strokes is increased to enhance power reserve, then the power reserve is improved, but the oscillation frequency is reduced

Engineering Contradiction:
Improvepower reserveVSAvoidoscillation frequency
Core Design Contradiction:
Duration of action of moving objectVSSpeed

Solution Approach 1:

The mechanism allows adjustment of the number of lost strokes by changing geometric parameters such as the angle of the blocking member, the position of the escape wheel teeth, or the configuration of the trigger mechanism. By varying these parameters, one can optimize the balance between power reserve (number of lost strokes) and oscillation frequency for different application requirements.

Inventive Principle:
Principle #35Parameter changes

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 mechanism maintains oscillation frequency while allowing for adjustable lost strokes, enhancing the power reserve and quality factor, making it suitable for both high-quality and conventional oscillators, and optimizing performance by controlling the number of lost strokes.

Implementation Method 1

a flexible pawl (30) for mounting on the balance wheel (10). This pawl (30) includes a finger (32) capable of cooperating with the release wheel (22) during the oscillations of the balance wheel (10)

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3405839B1Coup perdu escapement mechanism
Publication Date: 2020.06.17 FREYMOND ERIC
  • EP3405839B1 patent drawingFigure 1
  • EP3405839B1 patent drawingFigure 2~3
  • EP3405839B1 patent drawingFigure 4~5

AI summary

The invention relates to a coup perdu escapement mechanism including: an escapement wheel (12) intended for receiving energy from an energy source so as to rotate same, and for directly supplying a portion of energy to a balance (10); a blocking member (16) intended for cooperating with the escapement wheel (12) so as to block the rotation thereof; a release wheel (22) rotatably mounted and arranged to cooperate directly or indirectly with the escapement wheel (12); and a one-way drive system intended for being mounted on the balance (10). The mechanism is arranged such that the one-way drive system actuates the release wheel (22) once by oscillation so as to rotate same, periodically freeing the escapement wheel (12) so as to provide an impulse to the balance (10).