Electro-weldable Spring Hinge with Central Support Element

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Solution Overview

Problem

Small electro-weldable spring hinges used in eyeglasses often deform during the electric welding process, leading to impaired mobility and function due to high contact forces and material displacement, especially in thin housing areas.

Innovation Solution

A spring hinge design featuring a centrally arranged support element with a welding boss, which isolates the welding current and absorbs contact pressure, preventing deformation and allowing for direct current flow to the welding area, thus maintaining the hinge's structural integrity and mobility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If high contact forces are applied during electric welding, then a firm connection is created between the spring hinge and the spectacle element, but deformation of the housing and cavity occurs

Engineering Contradiction:
Improveconnection strengthVSAvoidhousing deformation
Core Design Contradiction:
StrengthVSShape

Solution Approach 1:

The housing is segmented into a wall section and a bottom section, with the support element arranged centrally in the bottom section. This segmentation allows the welding current to be directed specifically through the support element rather than through the entire housing, concentrating the thermal effect where needed while protecting the housing walls from excessive heat and deformation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The support element acts as an intermediary component between the welding current and the housing. It provides a dedicated path for current flow and serves as the primary contact point for welding forces, mediating the interaction between the external welding process and the internal housing structure to prevent direct transmission of harmful effects.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If welding current passes through the housing, then the welding process can be performed, but overheating and damage to thin housing areas and spring element occur

Engineering Contradiction:
Improvewelding processabilityVSAvoidoverheating damage
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The support element is designed with different properties than the housing walls - it has optimized electrical conductivity and mechanical strength specifically for withstanding welding currents and forces. This local differentiation allows the housing walls to remain thin and lightweight while the support element handles the welding stress, preventing overheating damage to critical areas.

Inventive Principle:
Principle #3Local quality

3Strength

If material displacement occurs during welding, then the welding connection is formed, but projections are created in the cavity that impair hinge element mobility

Engineering Contradiction:
Improvewelding connectionVSAvoidhinge element mobility
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The support element is extracted as a separate, freely arranged component within the housing rather than being integrated into the housing walls. This extraction allows it to be positioned optimally to absorb welding forces without transmitting them to the housing walls and cavity, preventing material displacement and projection formation that would interfere with hinge element movement.

Inventive Principle:
Principle #2Taking out (Extraction)

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

The design ensures optimal current flow and force distribution, preventing overheating and deformation, allowing for a stable and functional electro-welded spring hinge even in small dimensions, with improved assembly and cost-effectiveness.

Implementation Method 1

a welding current of 2,000 A to 8,000 A is passed through the housing of the spring hinge and the spectacle element... In the area of contact between the spring hinge and the frame of the glasses, there are weld bumps that heat up and melt when the current is high

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

the support element can also absorb the contact pressure forces introduced during the welding process in a particularly effective manner due to the advantageous central arrangement in the cavity

Methodology Applied
Scientific EffectMechanical force absorption: Mechanical Force

Data Source

PatentEP2153270B1Spring hinge
Publication Date: 2021.03.10 OBE OHNMACHT & BAUMGARTNER GMBH & CO KG
  • EP2153270B1 patent drawingFigure 1
  • EP2153270B1 patent drawingFigure 2
  • EP2153270B1 patent drawingFigure 3~4

AI summary

The invention relates to an electrically weldable spring hinge (1) for spectacles, comprising a housing (3), which is open on the bottom and has a cavity (17) into which a spring element can be inserted and in which at least one support element (19) is provided, and a hinge element (5) that is dispaceably arranged in the housing (3). According to the invention, the at least one support element (19) is arranged essentially centrically in the region of an open front-side section (S) of the housing (3) and, starting from a bottom surface (B) of the housing (3), protrudes in a free-standing manner into the cavity (17), a welding hump (23) for electrically welding the housing (3) to the element of the spectacles being provided on the bottom side of the support element (19), facing an element of the spectacles.