Elastic Stud Holder for Watch Hairspring Assembly

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Solution Overview

Problem

In mechanical watches, the assembly and adjustment of clockwork spiral springs are delicate and prone to errors due to restricted access and the risk of the hairspring tightening screw or eyebolt coming loose or being lost during manipulation.

Innovation Solution

An assembly comprising a stud holder with elastic means, including a base with a first stop and a second stopper, where the elastic means naturally exert stress on the eyebolt, allowing for simplified assembly and disassembly by deforming to enlarge or reduce the housing for the eyebolt, eliminating the need for complex screws or manipulations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional screw holders with tightening screws are used, then the stud can be securely held, but the assembly and disassembly become complex and time-consuming with risk of losing small parts

Engineering Contradiction:
Improveassembly and disassembly simplicityVSAvoidstud holder structure
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The stud holder is segmented into a base and separate elastic means (arms) that can independently deform. This segmentation allows the elastic arms to be manipulated separately for assembly/disassembly while the base remains stable, simplifying the operation without increasing overall structural complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The static stud holder structure is transformed into a dynamic system where elastic arms can deform reversibly. The arms transition between constrained and unconstrained states, enabling easy assembly by deforming the arms to enlarge the housing and simple disassembly by releasing the constraint, eliminating the need for complex screw mechanisms

Inventive Principle:
Principle #15Dynamics

2Reliability

If elastic means with natural constraint are used, then the stud is securely retained, but the housing space is limited

Engineering Contradiction:
Improvestud retention securityVSAvoidhousing space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The housing space is made dynamic through the elastic arms that can deform to enlarge the housing volume when needed. During normal operation, the arms maintain natural constraint with minimal space occupation. When assembly is required, the arms deform to temporarily increase housing space, allowing the stud to be inserted or removed without permanent increase in component size

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The physical state of the elastic arms changes between constrained and unconstrained configurations. This parameter change allows the housing space to vary dynamically - small during operation for compactness, and enlarged during assembly/disassembly operations, resolving the contradiction between secure retention and available space

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

Facilitates easy mounting and dismounting of the eyebolt without impact, reducing the risk of loss or loosening, and simplifies the assembly process by using elastic deformation to secure and release the eyebolt.

Implementation Method 1

the elastic means are made so as to naturally exert a constraint on the eye bolt when it is placed in the housing

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the housing being able to be enlarged to release the eye bolt by deformation of said elastic means

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP3032353B1Detachable stud support
Publication Date: 2019.08.07 ETA SA MFG HORLOGERE SUISSE
  • EP3032353B1 patent drawingFigure 1a~2a
  • EP3032353B1 patent drawingFigure 2b~3a
  • EP3032353B1 patent drawingFigure 3b~4c

AI summary

Assembly for holding or supporting a watch spiral spring, comprising a stud and a stud holder, which stud holder comprises: - a base (30, 300) having a first stop (32, 320) extending along a longitudinal axis (L) of said base; - means for attaching said stud holder to a balance bridge (5), said stud holder further comprising elastic means (34, 340) equipped with a second stop (36, 360).