Roof Window Mullion Dynamics for Aperture Utilization

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Solution Overview

Problem

Existing roof window arrangements do not fully utilize the aperture created in the roof structure due to the presence of mullions, which divide the aperture into smaller openings.

Innovation Solution

A roof window arrangement where at least one window unit has an openable pane-carrying sash that opens about a horizontal centre hinge axis, and the window units can be configured to open as a common openable sash in a second operational condition, allowing for better utilization of the roof aperture.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If mullions are used to separate window units in a roof window arrangement, then structural stability and individual window operation are improved, but the aperture utilization is reduced because the aperture is divided into smaller openings

Engineering Contradiction:
Improvestructural stabilityVSAvoidaperture utilization
Core Design Contradiction:
Stability of the object's compositionVSArea of stationary object

Solution Approach 1:

The mullion is designed with dynamic functionality, allowing it to switch between a fixed state (when window units are closed) and a movable state (when window units open). The mullion can be coupled to the common stationary frame or decoupled therefrom, enabling it to move together with the window units during opening operation. This dynamic characteristic allows the mullion to maintain structural stability when needed while enabling full aperture utilization during window operation.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If mullions are fixed to the common stationary frame, then individual window unit operation is enabled, but the ability to utilize the full aperture as a single opening is lost

Engineering Contradiction:
Improveindividual window operationVSAvoidcommon opening capability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The coupling mechanism between the mullion and common stationary frame is designed to be reversible. The mullion can be coupled to enable individual window operation, and decoupled to enable common opening of all window units together. This dynamic coupling capability provides adaptability and versatility, allowing the roof window arrangement to switch between different operational modes as needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The mullion serves multiple functions: it provides structural separation and stability when window units are closed, enables individual window operation when coupled to the frame, and allows common opening of all windows when decoupled. This multi-functionality resolves the contradiction between individual operation capability and common opening capability.

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

3Strength

If the aperture is divided into smaller openings by mullions, then structural support and hinge arrangement are improved, but light influx and fire escape functionality are reduced

Engineering Contradiction:
Improvestructural supportVSAvoidlight influx
Core Design Contradiction:
StrengthVSIllumination intensity

Solution Approach 1:

The mullion's ability to move with the window units during opening operation allows the aperture to be fully utilized when windows are open. When window units are opened individually or together, the mullion decouples from the stationary frame and moves accordingly, eliminating the division effect and maximizing light influx and fire escape functionality while maintaining structural support when closed.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4512974A1A roof window arrangement comprising a common stationary frame and at least a first window unit and a second window unit
Publication Date: 2025.02.26 VKR HOLDING AS
  • EP4512974A1 patent drawingFigure 1
  • EP4512974A1 patent drawingFigure 2
  • EP4512974A1 patent drawingFigure 3

AI summary

A roof window arrangement comprising a common stationary frame and at least a first window unit and a second window unit. A roof window arrangement comprising a common stationary frame configured to be built into a roof surface and at least a first window unit and a second window unit configured in a side-by-side configuration, where each window unit comprises a pane-carrying sash where at least one of the window units has an openable pane-carrying sash which opens about a horizontal centre hinge axis defined by a set of hinges arranged substantially at the centre of the window units in a height direction in a first operational condition and where the at least first window unit and second window unit are configured to open as a common openable sash in a second operational condition.