Bidirectional Watch Movement Date Ring Drive Mechanism

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Solution Overview

Problem

Existing electronic watch movements with unidirectional date ring rotation require significant energy and time to return to previous dates, as they can only move forward, necessitating almost a complete revolution and prolonged operation even in accelerated modes.

Innovation Solution

A watch movement with two bidirectional electric motors drives a date ring in both directions using a unidirectional drive mechanism with retractable drive elements, allowing quick date changes without additional motors, and is designed to be simple and cost-effective to manufacture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a unidirectional drive mechanism is used for the date ring, then the date can be advanced quickly in the forward direction, but returning to a previous date requires driving the date ring through almost a complete revolution which consumes significant energy and time

Engineering Contradiction:

Improvedate change speedVSAvoidenergy consumption for date correction

Core Design Contradiction:

SpeedVSUse of energy by moving object

Solution Approach 1:

The patent applies bidirectional drive capability to the date ring mechanism, allowing the date to be advanced or retreated by one day with equal ease. The drive wheel can rotate in both clockwise and counterclockwise directions, enabling correction of date display by driving the date ring in the opposite direction rather than completing a full revolution. This inversion of the unidirectional constraint resolves the energy and time consumption problem.

Inventive Principle:

Principle #13The other way round (Inversion)

2Adaptability or versatility

If a bidirectional motor is used to enable two-way date ring rotation, then quick date changes in both directions are achieved, but the device complexity and manufacturing cost increase

Engineering Contradiction:

Improvedate ring rotation directionVSAvoidmotor and mechanism complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments the drive mechanism into a drive wheel with direction-dependent drive elements. The drive wheel is designed with specific engagement features that enable bidirectional rotation control without requiring two separate motors. The mechanism is divided into functional segments (drive elements, date ring, engagement zones) that work together to achieve bidirectional control through a single motor's reversible rotation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs dynamic engagement and disengagement of drive elements based on rotation direction. The drive mechanism transitions between engaged and disengaged states depending on whether the motor rotates clockwise or counterclockwise. This dynamic behavior allows a single motor to control bidirectional date ring movement without requiring complex mechanical linkages or additional actuators.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If additional motors are added to enable bidirectional date ring drive, then quick date changes in both directions are achieved, but the device complexity and manufacturing cost increase significantly

Engineering Contradiction:

Improvedate ring bidirectional driveVSAvoidnumber of motors and mechanisms

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes a single motor perform multiple functions by enabling it to drive the date ring in both forward and reverse directions. The same motor that advances the date also retreats the date, eliminating the need for separate motors for each direction. The drive mechanism is designed to be universally controlled by one motor through directional rotation, reducing component count and simplifying the overall system architecture.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enables quick and efficient date changes in both directions without additional energy consumption, reducing operational time and complexity, while maintaining accurate date display.

Implementation Method 1

The present invention relates in particular to electronic watch movements comprising analog indicators driven by at least one electromagnetic motor

Methodology Applied

Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Data Source

PatentEP2937742B1Device for driving an analogue display of a timepiece

Publication Date: 2017.03.01 ETA SA MFG HORLOGERE SUISSE

AI summary

The watch movement comprises a first indicator (4) associated with a first drive mechanism (6) and a date ring (8) associated with a second drive mechanism (10). These first and second mechanisms are driven by a single bidirectional motor (12). The second mechanism is a unidirectional drive mechanism comprising a drive wheel (16) having fingers (18, 20) arranged such that, when this drive wheel is actuated in a given first direction, these fingers drive the date ring in its normal direction of advancement, and when the drive wheel is actuated in a second direction contrary to the first, these fingers are retracted so that they do not drive the ring. Furthermore, the first mechanism is arranged so that it drives the first indicator in its normal direction of advancement when the drive mechanism actuates the drive wheel in its second direction.