Flexible Rocker Control Mechanism for Blocked Calendar Correction

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Solution Overview

Problem

Existing calendar watch mechanisms risk component breakage when manually correcting indicators near midnight due to opposing forces during blocked star or disc rotation, and known solutions like a pivotable drive wheel finger lead to disengagement issues.

Innovation Solution

A control mechanism with a flexible second rocker arm that allows pivoting into a tilted position even when the star or disc is blocked, ensuring the same movement is achieved without component breakage by allowing the rocker to flex and maintain the same stroke length.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rigid control mechanism is used to advance calendar indicators, then the mechanism provides precise indexing control, but the mechanism risks breaking when antagonistic forces are exerted during manual correction near midnight

Engineering Contradiction:
Improvemechanical strengthVSAvoidmanual correction capability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The second arm is made elastically flexible rather than rigid, changing the mechanical parameter of stiffness to allow the arm to flex under antagonistic forces during manual correction, preventing breakage while maintaining control

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The elastic flexibility of the second arm serves as a pre-designed cushioning mechanism that absorbs antagonistic forces before they can cause mechanical failure, protecting the star wheel and disc from breakage during manual adjustment

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Manufacturing precision

If the second arm is made rigid to ensure precise force transmission, then the indexing accuracy is improved, but the mechanism becomes vulnerable to breakage when the star or disc is blocked

Engineering Contradiction:
Improveindexing accuracyVSAvoidresistance to mechanical failure
Core Design Contradiction:
Manufacturing precisionVSStrength

Solution Approach 1:

The second arm's elastic flexibility is carefully designed to maintain sufficient stiffness for accurate indexing while allowing enough compliance to prevent breakage when blocked, optimizing both precision and strength

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If a pin-driven finger mechanism is used to allow free pivoting, then manual correction can be performed without breakage risk, but the finger becomes de-indexed from the teeth

Engineering Contradiction:
Improvemanual correction safetyVSAvoidindexing accuracy
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The second arm acts as a flexible element that maintains continuous contact and indexing with the star wheel teeth while allowing controlled movement, replacing the pin-driven finger mechanism that caused de-indexing

Inventive Principle:
Principle #30Flexible shells and thin films

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

Prevents component breakage by allowing the rocker to pivot and maintain the same operational stroke length, even with blocked star or disc rotation, ensuring smooth and safe manual adjustment.

Implementation Method 1

a spring arranged to return the rocker in the rest position

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the second arm is elastically flexible enough to allow the rocker to come into the tilted position when the mechanism is actuated, even if the end of the second arm is retained because the rotation of the star or of the disc is otherwise blocked

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3992731B1Manually operable control mechanism for a timepiece
Publication Date: 2026.05.20 PATEK PHILIPPE SA
  • EP3992731B1 patent drawingFigure 1A~1C
  • EP3992731B1 patent drawingFigure 2a~2b

AI summary

The control mechanism comprises a manually actuated member from outside the timepiece, a rocker (3) pivotally mounted between a rest position and a tilted position, and a spring (9) arranged to return the rocker to the rest position. The rocker (3) has a first arm (5) arranged to cooperate with the manually actuated member so as to bring the rocker (3) into the tilted position when the member is actuated, and a second arm (7) whose end is arranged to push one of the teeth of a star wheel (11) so as to drive it by actuating the control mechanism. The second arm (7) is sufficiently flexible to allow the rocker (3) to move into the tilted position when the mechanism is actuated, even if the end of the second arm (7) is held because the rotation of the star wheel (11) is otherwise blocked.