Screwless Eyeglass Hinge Assembly for Durable Temple Pivoting

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Solution Overview

Problem

Existing eyeglasses require complex assembly processes involving small screws or other components for connecting the temple to the front, which is delicate and often requires specialized assistance, and the hinge is prone to failure under stress.

Innovation Solution

A simplified hinge design using an L-shaped connecting element with a spherical retention and locking element, allowing the temple to be coupled directly to the lens without screws or adhesives, ensuring durability and ease of assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional hinges with screws, rivets, or bushings are used to connect the temple to the front of the eyeglasses, then the connection can be achieved, but the assembly process becomes complex and requires specialized technicians

Engineering Contradiction:
ImproveEase of assemblyVSAvoidAssembly process complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent removes traditional fastening components (screws, rivets, bushings) from the hinge assembly, extracting only the essential connecting elements needed for the temple-to-front connection. This simplifies the assembly process while maintaining structural integrity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The hinge is designed to be self-assembling without requiring specialized tools or technicians. The temple can be coupled to the front by the user through simple manual insertion and engagement of the hinge components

Inventive Principle:
Principle #25Self-service

2Reliability

If traditional small hinge components are used, then the connection is achieved, but the hinge becomes delicate and prone to failure under stress

Engineering Contradiction:
ImproveHinge durabilityVSAvoidResistance to stress
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent merges multiple traditional hinge components into a single integrated hinge structure. This unified design eliminates weak points between separate parts and improves overall strength and reliability under repeated stress from opening and closing operations

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hinge utilizes composite construction combining different materials with complementary properties, creating a structure that is both durable and resistant to the intense stresses of repeated use and excessive temple opening

Inventive Principle:
Principle #40Composite materials

3Productivity

If traditional hinge assembly methods are used, then the connection is secure, but production time increases

Engineering Contradiction:
ImproveAssembly speedVSAvoidProduction time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The hinge components are pre-configured and pre-positioned during manufacturing, allowing for rapid final assembly. The temple can be coupled to the front in a single quick operation without requiring multiple assembly steps or adjustments

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

By removing complex fastening mechanisms and retaining only the essential connecting elements, the patent dramatically reduces assembly time while maintaining secure connection

Inventive Principle:
Principle #2Taking out (Extraction)

4Shape

If traditional hinge components are used, then the connection is achieved, but the aesthetics of the eyeglasses are compromised

Engineering Contradiction:
ImproveAesthetic appearanceVSAvoidNumber of components
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The patent combines multiple visible components into a single streamlined hinge structure, reducing visual clutter and improving the aesthetic appearance of the eyeglasses while maintaining all necessary functional elements

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3999899B1Eyeglasses with simplified hinge
Publication Date: 2026.01.14 LUXOTTICA SRL
  • EP3999899B1 patent drawingFigure 1~3
  • EP3999899B1 patent drawingFigure 4~5
  • EP3999899B1 patent drawingFigure 6~7

AI summary

Eyeglasses (1) with simplified hinge, comprising a pair of lenses (2), a pair of temples (3) and a hinge for connection between each one of the temples and the lenses; the hinge comprises an element (7) for connecting the lens (2) and the temple (3), adapted to be connected to the lens at one end and provided, at the opposite end, with a portion (6) adapted to engage a retention and locking element (9), the temple (3) being provided with a cavity (4) adapted to accommodate and lock the retention and locking element (9), the retention and locking element (9) acting as a rotation fulcrum for the temple (3) with respect to the connecting element (7).