Inflatable Sealing Element for Roof Window Gap Management

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Solution Overview

Problem

Existing roof windows face challenges in achieving optimal sealing, insulation, and sound dampening while maintaining smooth operation and minimizing frictional resistance during sash movement.

Innovation Solution

A roof window system featuring a flexible, tubular inflatable sealing element that fills with fluid in the closure position to seal gaps between the sash and frame, reducing friction and risk of damage, and deflates for easy operation, with the option to be placed on either the frame or sash, and integrated with a pressure source for controlled inflation and deflation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a traditional striking bead gasket is used on the sash and frame, then the sash can pivot smoothly during opening and closing, but the sealing and insulation performance is insufficient

Engineering Contradiction:
Improvesash pivoting smoothnessVSAvoidsealing and insulation performance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The sealing system is divided into two distinct levels: a traditional striking bead gasket that contacts first during closure to guide and protect the sash, and a secondary inflatable sealing element that engages afterward to provide enhanced sealing. This segmentation allows each component to perform its specific function optimally without interfering with the smooth pivoting operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The inflatable sealing element transitions from a deflated state during opening/closing operation to an inflated state during the closed position. This dynamic state change allows the sealing element to be flexible during movement (not interfering with pivoting) and rigid/sealing during the closed position (providing enhanced sealing and insulation).

Inventive Principle:
Principle #15Dynamics

2Reliability

If the gap between frame and sash is minimized to reduce heat loss and draught, then sealing performance improves, but the frame and sash members become more complex and harder to operate

Engineering Contradiction:
Improvesealing performanceVSAvoidframe and sash member complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Instead of reducing the gap dimension horizontally, the solution adds a vertical dimension by introducing an inflatable element that expands perpendicular to the gap plane. This allows the gap to remain physically present for smooth operation while the inflated element bridges the gap to provide sealing, effectively solving the problem in a different dimensional space.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The sealing element changes its physical parameters (volume, pressure, cross-sectional area) by inflating and deflating. During operation, it remains deflated with minimal impact on the gap; during closure, it inflates to increase its sealing cross-section, effectively reducing the functional gap without requiring permanent structural changes to the frame or sash.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If an inflatable sealing element is used to improve sealing and insulation, then heat loss and sound transmission are reduced, but frictional resistance during sash movement increases

Engineering Contradiction:
Improvesealing and insulationVSAvoidfrictional resistance during movement
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The inflatable sealing element operates in periodic cycles: deflated state during opening and closing movements (low friction period), and inflated state during the closed position (high sealing period). This periodic action ensures that the sealing element only engages when needed, minimizing frictional resistance during operation while maintaining excellent sealing when closed.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The sealing element dynamically changes its physical state between deflated and inflated based on operational requirements. During movement, it remains deflated to minimize contact and friction with the sash; during closure, it inflates to provide enhanced sealing. This dynamic adaptation resolves the contradiction between smooth operation and effective sealing.

Inventive Principle:
Principle #15Dynamics

4Reliability

If a larger abutment surface is provided between frame and sash to improve sealing, then closure effectiveness improves, but the operating force required increases

Engineering Contradiction:
Improveclosure effectivenessVSAvoidoperating force
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The solution replaces the need for large mechanical abutment surfaces with a pneumatic system. Instead of relying solely on mechanical compression of large surfaces to achieve sealing, an inflatable element uses internal fluid pressure to generate sealing force. This substitution allows effective closure with reduced operating force, as the inflation pressure provides the necessary sealing force without requiring large contact areas.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The sealing element changes its pressure parameter during operation. During closure, inflation pressure increases to provide strong sealing force; during operation, pressure is reduced or released to minimize resistance. This dynamic parameter change allows effective sealing without requiring continuously high operating forces.

Inventive Principle:
Principle #35Parameter changes

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

Enhances sealing and insulation, reduces operational force, and extends component lifetime by minimizing friction and snagging risks during closing, while maintaining effective sound dampening.

Implementation Method 1

the hollow profile being configured to assume an inflated state and a deflated state, the inflated state being obtained by filling with a fluid

Methodology Applied
Scientific EffectInflation: Pressure Increase

Implementation Method 2

at least one sealing element of said set is made from a flexible material and comprises a substantially tubular hollow profile

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4421262A1A roof window system comprising an inflatable sealing element, and a method of sealing such a roof window
Publication Date: 2024.08.28 VKR HOLDING AS
  • EP4421262A1 patent drawingFigure 1
  • EP4421262A1 patent drawingFigure 2~3
  • EP4421262A1 patent drawingFigure 4

AI summary

A roof window system (1) comprising of a frame (2) with a top member (21), a bottom member (24), two side members (22, 23), an operating element and a sealing element (80) with a tubular hollow profile (80.1). The sealing element (80) is made from a flexible material; thus the hollow profile (80.1) can assume an inflated or a deflated state by adding fluid via a pressure source. By positioning the operating element in a closure or an opening position, the hollow profile can become inflated or deflated, respectively, and improved sealing, insulation and/or sound dampening properties are achieved.