Free Escapement Mechanism with Impulse Spring for Timepiece

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Solution Overview

Problem

Existing free escapement mechanisms in clockwork movements suffer from energy losses and are sensitive to shocks due to the need for energy damping, which results in audible ticking and inefficiency, particularly during the mute phase where energy is not transmitted effectively.

Innovation Solution

A free escapement mechanism that uses two triggers to control the escapement wheel, allowing energy transmission during both alternations of the balance wheel, with an impulse spring storing energy during the winding phase and releasing it during the mute phase, reducing energy losses and making the mechanism insensitive to shocks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If energy damping is used to control the escape wheel, then the mechanism can prevent snagging due to manufacturing tolerances, but energy is lost and audible ticking sound is generated

Engineering Contradiction:

Improveprevention of snaggingVSAvoidenergy damping loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

A spring element is introduced as an intermediary between the escape wheel teeth and the control element. This spring absorbs dimensional variations and manufacturing tolerances through its elasticity, preventing snagging while allowing energy to be stored and released smoothly without direct impact damping losses

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The spring element is pre-loaded to provide a cushioning effect before contact between escape wheel teeth and control element. This beforehand cushioning compensates for manufacturing tolerances and prevents snagging without requiring energy damping during operation

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Use of energy by moving object

If the escape wheel accelerates and transmits energy to the oscillator before damping on the pallet fork, then energy transmission occurs, but considerable energy loss and audible ticking sound result

Engineering Contradiction:

Improveenergy transmission to oscillatorVSAvoidenergy damping loss

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The spring acts as a mediator that stores energy during the impulse phase and releases it during the silent phase, smoothing energy transmission to the oscillator and eliminating the need for energy damping that causes ticking sounds

Inventive Principle:

Principle #24Intermediary (Mediator)

3Device complexity

If the gear train advances once per oscillator period in detent escapements, then the mechanism is simple, but the oscillator is not self-starting due to lack of impulse during silent phase

Engineering Contradiction:

Improveescapement mechanism simplicityVSAvoidself-starting capability

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

The spring element continues to store and release energy during both the impulse phase and the silent phase, providing continuous useful action to the oscillator. This ensures the oscillator receives energy during each alternation and maintains self-starting capability without increasing overall mechanism complexity

Inventive Principle:

Principle #20Continuity of useful action

4Reliability

If anchor escapements transmit energy indirectly via the anchor, then control is improved, but energy transmission efficiency decreases and ticking sound increases

Engineering Contradiction:

Improvecontrol stabilityVSAvoidindirect energy transmission loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The spring element is extracted from the traditional anchor mechanism and positioned to act directly on the escape wheel teeth. This allows the spring to store and release energy directly during the impulse phase, improving energy transmission efficiency while the control element maintains reliable control through the spring's cushioning effect

Inventive Principle:

Principle #2Taking out (Extraction)

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 design ensures energy is transmitted to the oscillator during each alternation, minimizing energy loss and reducing the audible ticking, making the escapement mechanism more efficient and shock-resistant, allowing for a higher number of teeth on the escape wheel without increasing diameter, and maintaining precise timekeeping.

Implementation Method 1

an impulse spring storing energy during the winding phase and releasing it during the mute phase

Methodology Applied

Scientific EffectElastic potential energy storage and release: Elasticity

Data Source

PatentEP2660661B1Free escapement mechanism for timepiece movement, movement and/or timepiece comprising said escapement mechanism

Publication Date: 2019.06.26 PATEK PHILIPPE SA

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AI summary

The mechanism has a pulse mobile unit (2) pivoted on a frame of a clockwork movement and comprising a fork (2.3) engaged with a pulse pin (7.7) of a plate (7). An elastic arm (2.5) is terminated by a hook (2.6) engaged with teeth of an escape wheel (1.2). A control unit formed of detents (5, 6), a release nose (7.6) and a release pin (7.10) is arranged to release the escape wheel from a step during first alternation of a balance spring (3) in a rotation direction and releasing the hook from teeth of an escape wheel during second alternation of the balance spring in second rotation direction. An independent claim is also included for a detent for an escape mechanism of clockwork movement.