Roof Window Hinge With Friction Braking for Position Holding

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Solution Overview

Problem

Existing hinges for roof windows, particularly those with linkage mechanisms, lack effective control over output forces and ease of operability, leading to potential accidents and difficulty in modulating the opening and closing movements.

Innovation Solution

A hinge design featuring a linkage mechanism with sliding joints, guide tracks, and a braking device that includes a friction element, such as a friction disc or squeeze blocks, to manage the movement pattern and ensure smooth, stable operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional hinges with simple rotation around a fixed axis are used, then the structure is simple, but the window pane sash cannot be held at arbitrary positions and may fall due to gravity

Engineering Contradiction:
Improveposition holding capabilityVSAvoidhinge structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The hinge transitions from a static fixed-axis rotation to a dynamic mechanism with multiple links (first link 150, second link 160) that can adapt their configuration. The linkage mechanism allows the sash to be held at arbitrary positions by adjusting the angles between links, providing position holding capability while maintaining operational flexibility.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The hinge is divided into multiple independent components: frame hinge part 130, sash hinge part 140, first link 150, second link 160, and braking device 180. This segmentation allows each component to perform its specific function independently, with the linkage mechanism providing motion control and the braking device providing position locking, thereby achieving reliable position holding through coordinated action of segmented parts.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If a linkage mechanism with multiple links is introduced to enable arbitrary position holding, then position control is improved, but the device complexity increases

Engineering Contradiction:
Improvearbitrary position holdingVSAvoidhinge mechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The linkage mechanism serves multiple functions simultaneously: it enables arbitrary position holding, provides mechanical advantage for operation, and works in conjunction with the braking device to maintain positions. The first link 150 and second link 160 together form a versatile mechanism that handles both motion control and position stabilization, reducing the need for separate dedicated components.

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

Solution Approach 2:

The braking device 180 is integrated within or alongside the linkage mechanism structure, with friction elements positioned to act on the links or joints. This nesting allows the braking function to be incorporated into the existing linkage structure rather than requiring a completely separate positioning system, thereby managing complexity through compact integration.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Reliability

If friction elements are added to create a braking device for position holding, then position stability is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveposition stabilityVSAvoidhinge manufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The friction elements in the braking device 180 are designed to automatically engage and disengage based on the operational state of the hinge. When the sash is moved to a desired position, the braking mechanism self-activates to maintain that position without requiring additional actuators or complex control systems. This self-service capability simplifies manufacturing by eliminating the need for powered positioning systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The friction elements are designed as simple, inexpensive components that can be easily manufactured and replaced if needed. Rather than using complex mechanical locks or powered actuators, the patent employs friction-based elements that provide sufficient position holding capability through simple material properties and geometric design, reducing manufacturing complexity and cost.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

4Adaptability or versatility

If the hinge mechanism includes multiple links and braking devices, then the window sash can be held at arbitrary positions, but the number of parts increases

Engineering Contradiction:
Improvearbitrary position capabilityVSAvoidnumber of parts
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The frame hinge part 130 and sash hinge part 140 are combined with the linkage mechanism (first link 150, second link 160) and braking device 180 into an integrated hinge assembly. Rather than treating these as separate systems, they are merged into a single coordinated mechanism where the linkage and braking components work together with the hinge parts to provide unified position control and holding functionality.

Inventive Principle:
Principle #5Merging (Combining)

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 hinge provides safer and easier opening and closing of roof windows by modulating movements, minimizing the risk of accidents and ensuring stable, controlled operation.

Implementation Method 1

The braking device (180) comprises one or more friction elements

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4365398B1Hinge for a roof window and roof window with a set of hinges
Publication Date: 2026.04.29 VKR HOLDING AS
  • EP4365398B1 patent drawingFigure 1
  • EP4365398B1 patent drawingFigure 2~3
  • EP4365398B1 patent drawingFigure 4~5

AI summary

In the roof window, each hinge (110) of the set of hinges comprises a frame hinge part (130), a sash hinge part (140), and a movement supporting assembly comprising guiding means including a linkage mechanism with at least two links (150, 160) providing connection between the sash hinge part and the frame hinge part. Each link is connected to at least one of the frame hinge part and the sash hinge part at a joint and connected to each other. The hinge (110) furthermore comprises a braking device (180) acting on at least one element of the movement supporting assembly over at least a part of the opening and/or closing movement. The braking device (180) comprises one or more friction elements.