PVC–Aluminum Window Frame Clip Connection for Thermal Expansion

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Solution Overview

Problem

Existing methods for connecting PVC window frames with aluminum facings fail to effectively compensate for manufacturing tolerances and thermal expansion differences between PVC and aluminum, leading to potential misalignment and instability.

Innovation Solution

A composite frame design using connecting clips with spreading springs and elastic elements that allow for secure attachment of aluminum facings to PVC profiles, accommodating manufacturing tolerances and thermal expansion through elastic deformation and rotational movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If rigid connecting clips with fixed positioning are used to attach aluminum facings to PVC profiles, then precise alignment can be achieved, but manufacturing tolerances and thermal expansion cannot be compensated

Engineering Contradiction:
Improvealignment precisionVSAvoidtolerance compensation
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The connecting clip incorporates a rotatable element that can rotate within a defined range, transforming the rigid connection into a dynamic one. This rotation capability allows the connection to adapt to manufacturing tolerances and thermal expansion while maintaining precise alignment when properly installed

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The connecting element features an inclined surface that converts rotational movement into linear displacement. As the rotatable element rotates, the inclined surface translates this motion into positional adjustment, enabling the connection to compensate for dimensional changes due to temperature or manufacturing variations

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If multiple connecting clips are arranged in a straight line with fixed positioning, then structural stability is improved, but deviations from straight line alignment cannot be compensated

Engineering Contradiction:
Improvestructural stabilityVSAvoidstraight line alignment
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

Each connecting clip includes a rotatable element that can independently adjust its position within a defined range. This dynamic capability allows each clip to compensate for deviations from perfect straight line alignment while maintaining overall structural stability through the collective action of multiple clips

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The connection system divides the rigid alignment requirement into multiple independent adjustable segments. Each connecting clip acts as an independent unit with rotation capability, allowing local adjustments without affecting the entire assembly, thus accommodating deviations while maintaining overall stability

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If fixed-height clip connectors are used to attach metal profiles to wooden frames, then assembly simplicity is improved, but thermal expansion differences between materials cannot be compensated

Engineering Contradiction:
Improveassembly simplicityVSAvoidthermal expansion compensation
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The connecting element incorporates a rotatable component that can move dynamically to accommodate thermal expansion and contraction. This dynamic feature is integrated into an otherwise simple clip connector design, maintaining ease of assembly while adding the capability to compensate for material expansion differences

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The rotatable element with inclined surface acts as an intermediary mechanism between the fixed clip connector and the materials being joined. It mediates the thermal expansion forces by converting them into rotational movement, protecting both the clip and the materials from stress

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution provides a stable and secure connection that compensates for manufacturing tolerances and thermal expansion, ensuring precise alignment and durability of the composite frame.

Implementation Method 1

a spreading spring arranged on both sides of the plate

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

An elastic spring is arranged on one side of the plate... allowing for a secure connection that can simultaneously compensate for manufacturing tolerances and heat-induced movements

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4411097B1Connection of a PVC window frame with aluminium facing shells or frames
Publication Date: 2025.10.15 PROFINE GMBH
  • EP4411097B1 patent drawingFigure 1
  • EP4411097B1 patent drawingFigure 2~5
  • EP4411097B1 patent drawingFigure 6~7

AI summary

A composite frame for a window or door comprises an outer cover frame made of metal profiles connected to each other at the corners, or at least one outer metal cover shell (2, 3), and a base frame made of plastic profiles (5, 6) welded together at the miter joints. The outer cover frame or the at least one outer metal cover shell (2, 3) is connected to the base frame by means of connecting clips (1). The connecting clip (1) has a plate (7) that is at least approximately flat, with expanding springs (8, 9) spaced apart on both sides of the plate (7). An elastic spring (10) is arranged on one side of the plate (7). Bores (12, 13) are arranged in the outer surfaces (14, 15) of the plastic profiles (5, 6). The metal profiles or outer metal cover shells (2, 3) are connected to the plastic profiles (5, 6) by means of the connecting clips (1).