Tilt-Turn Roof Window Locking for Intuitive Mode Switching

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Solution Overview

Problem

Existing tilt and turn type roof windows require unintuitive user operations to select between tilt and turn modes, are aesthetically unappealing, and may suffer from mechanical complexity leading to reliability issues.

Innovation Solution

A tilt and turn type roof window with a first handle that remains in a fixed position during both tilt and turn modes, allowing intuitive operation, and a second handle for unlocking, combined with a lock system that enables easy retrofitting of an electric actuator, ensuring mechanical simplicity and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a lock system requires manual unlocking before turning the window in turn mode, then the window can be securely locked in closed position, but the user operation becomes unintuitive and complex

Engineering Contradiction:
Improvelocking reliabilityVSAvoiduser operation intuitiveness
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The lock system is segmented into two independent locks: a first lock for securing the movable unit to the fixation frame in closed position, and a second lock for enabling turn mode operation. This segmentation allows each lock to have a specific function, making the operation sequence simpler and more intuitive while maintaining security.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first lock is designed to automatically unlock when the movable unit is tilted open in tilt mode, eliminating the need for manual unlocking operations. This preliminary automatic action simplifies the user interface and makes the operation more intuitive while maintaining reliable locking when closed.

Inventive Principle:
Principle #10Preliminary action

2Ease of operation

If the handle position changes during operation to indicate mode selection, then user feedback is provided, but the mechanism becomes more complex and less reliable

Engineering Contradiction:
Improvemode selection feedbackVSAvoidhandle mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

Instead of moving the handle to indicate mode selection, the invention keeps the handle in a fixed position and uses the lock system state to indicate the operational mode. This inversion simplifies the handle mechanism while providing clear user feedback through the locking status.

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If the lock directly interlocks the movable unit and fixation frame, then secure locking is achieved, but retrofitting electric actuators becomes difficult

Engineering Contradiction:
Improvelocking securityVSAvoidactuator retrofitting ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

An interconnecting part is introduced as an intermediary element between the movable unit and the fixation frame. The first lock interlocks this interconnecting part to the fixation frame, while the movable unit connects to the interconnecting part through hinges. This intermediary structure maintains secure locking while providing accessible mounting points for retrofitting electric actuators.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of operation

If multiple handles and locks are used for tilt and turn modes, then operational control is precise, but the aesthetic appearance deteriorates

Engineering Contradiction:
Improveoperational control precisionVSAvoidaesthetic appearance
Core Design Contradiction:
Ease of operationVSShape

Solution Approach 1:

The first and second locks are integrated into a unified lock system that can be operated through a single handle mechanism. This merging reduces the number of visible components while maintaining precise operational control for both tilt and turn modes, improving aesthetic appearance.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4650545A1A tilt and turn type roof window comprising a movable unit configured to be manually tilted and turned
Publication Date: 2025.11.19 VKR HOLDING AS
  • EP4650545A1 patent drawingFigure 1
  • EP4650545A1 patent drawingFigure 2
  • EP4650545A1 patent drawingFigure 3

AI summary

The present disclosure relates to a roof window (1) of the tilt (AX1) and turn (AX2) type, for a building. The roof window (1) comprises a first lock (12, 25) which in a locked state is configured to interlock an interconnecting part (11, 11a, 11b) and a fixation frame (2) of the roof window (1), at least in a turn mode (TUM), so that turning of the movable unit (3) around a turn axis (AX2) is allowed while a first lock (12, 25) is in a locked state and while a first handle (8) of the roof window (1) remains in a first handle position (HP1). A second lock (15) is, in a locked state, configured to lock the movable unit (3) in a third, closed and locked mode (CLM). A second handle (18) is configured to be operated so as to switch the second lock (15) between the locked state and an unlocked state. The movable unit (3) is configured to be turned relative to the interconnecting part (11, 11a, 11b) around said turn axis (AX2) by means of the second handle (18) while the first handle (8) is in a second handle position (HP2) and while the first lock (12, 25) is in an unlocked state. The present disclosure also relates to a method of retrofitting a tilt and turn type roof window to comprise an electrically powered actuator (9).