Electroformed Barrel Spring Hooking Zone for Wider Material Use

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Solution Overview

Problem

Conventional methods for manufacturing barrel springs for watch movements are limited to specific materials and are not suitable for electroplated materials, due to their complexity in small dimensions and particular shapes, restricting the variety of materials that can be used.

Innovation Solution

A method for manufacturing barrel springs with an original attachment zone using electroforming, forming a spiral metal blade and attachment zone by photolithography, electrodeposition, and other techniques like chemical etching or additive manufacturing, allowing for precise production in various materials, including those that cannot undergo rolling or stamping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional wire drawing and rolling methods are used to manufacture barrel springs, then the manufacturing process is well-established and reliable, but the material selection is limited and cannot include electroplated materials

Engineering Contradiction:
Improvematerial selection rangeVSAvoidmanufacturing process complexity
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent changes the manufacturing parameters from conventional wire drawing and rolling to electroforming processes, allowing the use of electroplated materials and other non-traditional materials while maintaining manufacturing reliability through controlled electrochemical deposition parameters

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces mechanical wire drawing and rolling processes with electrochemical electroforming processes, enabling the manufacture of barrel springs from materials that cannot undergo mechanical deformation such as electroplated layers and brittle materials

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If separate steps are used to produce the rectangular opening and shell for mounting, then each component can be optimized independently, but the manufacturing process becomes more complex and time-consuming

Engineering Contradiction:
Improveattachment zone precisionVSAvoidmanufacturing process steps
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent merges the production of the barrel spring body and the attachment zone (rectangular opening and shell) into a single integrated electroforming process, eliminating separate manufacturing steps while maintaining the precision of the attachment features through direct formation from the mold

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent incorporates the attachment zone features (rectangular opening and mounting shell) directly into the electroforming mold design, so that these features are pre-formed during the initial electroforming process rather than requiring subsequent separate manufacturing steps

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If traditional ferrules or eyelets are used for mounting, then the attachment mechanism is simple and well-established, but the design flexibility and material options are restricted

Engineering Contradiction:
Improvedesign flexibilityVSAvoidattachment reliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent integrates the attachment zone directly into the barrel spring structure through electroforming, merging the spring body and mounting features into a single unified component, which eliminates the need for separate ferrules or eyelets while enhancing design flexibility and material compatibility

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent enables the use of composite or layered materials such as electroplated layers on substrate materials, allowing combination of different material properties (e.g., corrosion resistance from plating with structural integrity from substrate) while maintaining attachment reliability through the integrated electroformed structure

Inventive Principle:
Principle #40Composite materials

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 the production of barrel springs in a wide range of materials, particularly those that cannot be rolled or stamped, ensuring precise attachment and maintenance on the barrel shaft, overcoming the limitations of conventional methods.

Implementation Method 1

a phase of filling said at least one level of the mold by electrodeposition of a metallic material

Methodology Applied
Scientific EffectElectrodeposition: Electrodeposition

Data Source

PatentEP3499316B1Barrel spring for a clock movement of a timepiece and method for manufacturing such a spring
Publication Date: 2024.08.07 NIVAROX FAR SA
  • EP3499316B1 patent drawingFigure 1~3
  • EP3499316B1 patent drawingFigure 4~6
  • EP3499316B1 patent drawingFigure 7~9

AI summary

The invention relates to a barrel spring (1a, 1b, 1c, 1d, 1e) comprising a spiral metal blade (3) and a hooking zone (4a, 4b, 4c, 4d, 4e) defined in an inner face (5) of an inner end (6) of said blade (3), the hooking zone (4a, 4b, 4c, 4d, 4e) comprising at least one profile (7a) and/or at least one cavity (7b) included in said inner face (5) of this inner end (6).