Plastic Windshield Carrier with Compression Zones

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Solution Overview

Problem

Conventional carriers or holders for rain sensors, light sensors, cameras, and mirrors attached to vehicle windshields using hard adhesives face issues with thermal expansion, leading to glass breakage or bond failure, necessitating the use of expensive materials with minimal thermal expansion.

Innovation Solution

A plastic carrier or holder with compression and expansion zones, designed to absorb thermal changes without transmitting excessive forces to the adhesive surface, allowing for a rigid and cost-effective non-metallic solution that accommodates thermal expansion while maintaining a secure bond with hard adhesives.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a hard adhesive is used to fix the carrier to the windshield, then the bond strength is improved, but the glass may break or the bond may fail due to thermal expansion

Engineering Contradiction:
Improvebond strengthVSAvoidbond reliability under thermal stress
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The carrier is divided into distinct functional zones: rigid adhesive bonding zones that provide strong attachment to the windshield, and flexible compression/expansion zones that accommodate thermal movement. This segmentation allows different parts of the carrier to perform different functions - maintaining bond strength while preventing thermal stress damage to the glass.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the carrier are given different mechanical properties. The adhesive bonding areas are designed to be rigid and strong, while the compression and expansion zones are designed to be more compliant and flexible. This local differentiation of material properties allows the carrier to simultaneously achieve strong bonding and thermal stress accommodation.

Inventive Principle:
Principle #3Local quality

2Reliability

If metal materials with low thermal expansion are used for the carrier, then the thermal expansion problem is solved, but the cost increases significantly

Engineering Contradiction:
Improvethermal expansion stabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of changing the base material to expensive metal, the invention changes the effective thermal expansion parameter by introducing compliant zones within the plastic carrier structure. The compression and expansion zones modify the overall thermal response of the carrier, allowing it to accommodate expansion without requiring low-expansion materials.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The carrier functions as a composite structure combining rigid and flexible zones within a single plastic component. This internal composite design allows the carrier to exhibit both rigid bonding characteristics at the adhesive surfaces and flexible thermal accommodation in the compression/expansion zones, achieving metal-like thermal performance at plastic-like cost.

Inventive Principle:
Principle #40Composite materials

3Stability of the object's composition

If the carrier is made rigid to ensure sensor attachment stability, then the sensor positioning is improved, but the adhesive bond fails under thermal stress

Engineering Contradiction:
Improvesensor positioning stabilityVSAvoidadhesive bond reliability
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The carrier is segmented into rigid adhesive bonding zones that ensure stable sensor attachment and flexible compression/expansion zones that protect the adhesive bond from thermal stress. This segmentation allows the sensor mounting area to remain stable while the transition zones absorb thermal movements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The compression and expansion zones act as pre-designed cushioning elements that absorb thermal stresses before they can reach the adhesive bonds. These zones are positioned in advance to intercept and mitigate thermal forces, protecting the rigid bonding areas from stress-induced failure.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 plastic carrier or holder effectively absorbs thermal expansion without causing glass breakage or bond failure, enabling the use of less expensive materials and ensuring the adhesive system's stability under heat and pressure, suitable for automotive applications.

Implementation Method 1

the plastic carrier or holder can be made of plastic, that is to say of materials which inherently have a greater thermal expansion

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

the hard adhesive is no longer subject to expansion, since it only establishes a connection to the carrier or holder in certain areas

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP2179894B1Holder or carrier for a rain sensor, light sensor, a camera, a mirror or similar on a windscreen
Publication Date: 2012.07.11 SAINT GOBAIN VITRAGE SA
  • EP2179894B1 patent drawingFigure 1
  • EP2179894B1 patent drawingFigure 2

AI summary

The holder/carrier (1) has a single-piece plastic mold part (3) provided with adhesion surfaces (4, 5), where the holder or carrier is fixed at disk surfaces by a contact adhesive. The holder or carrier is formed from a single-piece body. A compression zone (6) or an extension zone (7) is formed between the adhesion surfaces in a molding operation. The body has a closed circumferential wall (8) with an edge region (9). The adhesion surfaces are formed for receiving the contact adhesive. The compression zone and the extension zone are arranged in the wall.