Glass Opening Reinforcement via Bushing Compressive Stress

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Solution Overview

Problem

Glass products with openings are weakened and prone to breaking due to tensile stress, as conventional tempering processes cannot be applied after forming holes, and existing reinforcement methods are inadequate for maintaining durability and strength.

Innovation Solution

A glass product with a bushing and adhesive system that introduces compressive stress at the opening by expanding and contracting the bushing, which is thermally or mechanically expanded and then adhered to the glass edge, creating a compressive force that strengthens the glass around the opening.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an opening is formed in a glass sheet, then the glass sheet can be used for applications requiring openings (e.g., wiper passages, antenna holes), but the glass sheet is weakened and prone to breaking under tensile stress

Engineering Contradiction:
Improveapplicability for openingsVSAvoidstrength at opening
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The patent applies local quality by introducing a reinforcement element specifically at the opening area where stress concentration occurs. The reinforcement member is positioned locally at the opening rather than throughout the entire glass sheet, providing targeted strengthening where needed while maintaining the overall glass properties elsewhere.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining the glass sheet with a reinforcement member made of different materials (such as metal, polymer, or ceramic). This composite structure leverages the strengths of both materials - the optical and chemical properties of glass combined with the mechanical strength of the reinforcement material - to create a glass assembly that maintains strength despite having an opening.

Inventive Principle:
Principle #40Composite materials

2Strength

If thermal tempering is applied to strengthen glass, then the glass gains permanent residual surface compression and becomes difficult to break, but the glass cannot be cut or shaped after tempering

Engineering Contradiction:
Improvesurface compression strengthVSAvoidpost-tempering processing
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by forming openings and installing reinforcement members in the glass sheet before the tempering process. This sequence allows the glass to be cut, drilled, and reinforced while still in its annealed state, and then strengthened through tempering afterward. The reinforcement member is positioned in advance to withstand the thermal stress of tempering and provide ongoing strength enhancement.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If laminated glass is used to provide impact protection, then the glass offers better safety and various functional benefits, but the complexity of the glass structure increases

Engineering Contradiction:
Improveimpact protectionVSAvoidlaminated structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies universality by designing the reinforcement member to serve multiple functions simultaneously. The reinforcement member not only strengthens the glass at the opening but also acts as a bonding interface between laminate layers, provides a mounting surface for components, and can incorporate sealing or insulation functions. This multi-functionality reduces the need for separate components and simplifies the overall structure despite the laminated configuration.

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

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 method effectively enhances the strength and durability of glass products with openings by distributing compressive stress, reducing the risk of cracking and fractures, and can be applied to both tempered and non-tempered glass, including laminated glass sheets.

Implementation Method 1

The bushing may be made of a metal or metal alloy, and preferably may be aluminum or its alloy. The bushing is subject to tension.

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

A sheet of glass having an opening may undergo tempering to provide a strengthened glass sheet. Tempering glass is a thermal or chemical process that provides a strengthened glass sheet having permanent residual internal tension and surface compression.

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Implementation Method 3

The adhesive may be thermally, chemically, or ultraviolet radiation cured.

Methodology Applied
Scientific EffectThermal curing: Heating

Implementation Method 4

The adhesive may be thermally, chemically, or ultraviolet radiation cured.

Methodology Applied
Scientific EffectChemical curing: Chemical Bonding

Implementation Method 5

The adhesive may be thermally, chemically, or ultraviolet radiation cured.

Methodology Applied
Scientific EffectUV radiation curing: Photopolymerisation

Data Source

PatentEP3833564B1Methods of reinforcing openings in glass and products formed therefrom
Publication Date: 2022.06.29 CENT GLASS CO LTD
  • EP3833564B1 patent drawingFigure 1~3
  • EP3833564B1 patent drawingFigure 4~6
  • EP3833564B1 patent drawingFigure 7~10

AI summary

A glass product includes a glazing having at least one glass sheet, an opening extending through the glazing, a bushing extending through the opening; and an adhesive provided between an edge of the opening and an outer edge of the bushing, wherein compressive stress is formed in the glazing around the opening in the glazing by contraction of the bushing.