Spring Contactor for Watch Battery Electrical Connection

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Solution Overview

Problem

Existing watch designs face challenges in maintaining a permanent and reliable electrical connection between the battery and circuit, especially under conditions of acceleration or impact, requiring multiple components and complex assembly processes.

Innovation Solution

A single spring contactor is used to secure the circuit and battery assembly by pinching it during the watch's closure, ensuring excellent electrical contact without additional components like screws or rivets, utilizing a rigid spring with elastic return means to maintain contact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple components (screws, rivets, etc.) are used to secure the battery and circuit assembly, then the reliability of electrical connection is improved, but the device complexity and assembly time increase

Engineering Contradiction:
Improveelectrical connection reliabilityVSAvoidnumber of components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the functions of multiple separate components (screws, rivets, spring tabs) into a single integrated spring contactor assembly. This contactor simultaneously provides mechanical securing and electrical connection functions, eliminating the need for multiple discrete fastening components while maintaining connection reliability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spring contactor is designed as a multi-functional component that performs multiple roles: it mechanically secures the battery and circuit assembly, provides elastic return force to maintain contact pressure, and establishes electrical connections. This universal component replaces several specialized components with a single element that accomplishes all necessary functions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If multiple components and assembly steps are used to ensure permanent electrical connection, then the reliability under acceleration and impact is improved, but the assembly time and manufacturing cost increase

Engineering Contradiction:
Improveconnection permanence under acceleration and impactVSAvoidassembly time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The spring contactor is pre-configured with built-in elastic return means that automatically engage and secure the battery and circuit assembly when the back is closed. The elastic deformation and recovery of the spring tabs create immediate mechanical interlocking and electrical contact without requiring separate assembly steps for fastening and connection.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs dynamic spring elements that can elastically deform to accommodate variations in assembly tolerances and maintain constant contact pressure under different operating conditions including acceleration and impact. This dynamic response ensures permanent reliable connection without requiring over-engineered rigid fastening systems.

Inventive Principle:
Principle #15Dynamics

3Reliability

If a rigid spring contactor with elastic return means is used to secure the assembly, then the electrical contact quality is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveelectrical contact qualityVSAvoidmanufacturing simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent utilizes changes in the physical parameters of the spring contactor, specifically its elastic properties and geometric configuration, to achieve reliable electrical contact. The spring tabs are designed with specific dimensions and material properties that enable them to deform elastically and maintain optimal contact pressure, ensuring high-quality electrical connection through parameter optimization rather than complex manufacturing processes.

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 solution provides a cost-effective and time-efficient method to ensure permanent electrical connection between the battery and circuit, minimizing components and assembly complexity while maintaining reliability under various usage conditions.

Implementation Method 1

contactor (8) is rigid and comprises elastic return means tending to bring it back to a geometry of rest

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP2650734B1Battery attachment with improved contact
Publication Date: 2018.01.24 ETA SA MFG HORLOGERE SUISSE
  • EP2650734B1 patent drawingFigure 1~8
  • EP2650734B1 patent drawingFigure 3~7

AI summary

The structure has a back cover (3) for confining an electronic/electrical module including a plate (4) with a compartment (41) arranged to receive an electrical energy accumulator (5). The module comprises a rigid connecting contactor i.e. spring, for providing electrical connection between the accumulator and a contact area of a circuit (6), where the contactor comprises an elastic return unit tending to return the contactor to a rest geometry. The contactor comprises two arms (82, 86) together for forming a clamp for pressing the circuit of the module and the accumulator toward each other. The accumulator is a cell battery.