Roof Window Hinge With Adjustable Guide for Smooth Movement

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Solution Overview

Problem

The loose movement between the frame-mounted and sash-mounted components of roof windows becomes less smooth over time due to the weakening of the leaf spring, requiring replacement, which is wasteful and costly for homeowners who lack the necessary skills.

Innovation Solution

A hinge system with an expandable element, such as a compressible bushing, is integrated into the guide means of the sash-mounted component, allowing adjustment of its width and depth within the channel of the frame-mounted component, controlled by an actuator for improved friction and smoother operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a leaf spring is used in the frame-mounted component to cushion the movement of the stud, then the movement between the sash and frame becomes smoother, but the leaf spring deforms and weakens over time due to repeated impacts, causing the channel to widen and movement to become loose

Engineering Contradiction:
Improvesmoothness of movementVSAvoiddurability of leaf spring
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The invention removes the leaf spring from the frame-mounted component entirely. Instead, a separate cushioning element is provided in the sash-mounted component that contacts the frame-mounted component during operation. This extraction eliminates the problem of the leaf spring weakening and deforming over time while maintaining the cushioning function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of placing the cushioning element (leaf spring) in the frame-mounted component as in conventional designs, the invention inverts the arrangement by placing the cushioning element in the sash-mounted component. This inversion allows the cushioning element to be replaced independently without replacing the entire frame-mounted component, and enables the guide means to be adjusted for proper engagement with the channel.

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

2Ease of operation

If the leaf spring is replaced when weakened, then smooth movement is restored, but this requires skilled labor and is costly for roof-window owners

Engineering Contradiction:
Improvesmoothness of movementVSAvoiddifficulty of replacing leaf spring
Core Design Contradiction:
Ease of operationVSEase of repair

Solution Approach 1:

The invention divides the hinge system into separable components: the frame-mounted component and the sash-mounted component. The cushioning element is integrated into the sash-mounted component, which can be independently removed and replaced by the user without requiring skilled labor to access and replace the leaf spring in the frame-mounted component.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The design enables users to perform maintenance themselves. The sash-mounted component with the integrated cushioning element can be easily removed and replaced by the user without requiring specialized skills or tools, eliminating the need to hire skilled laborers for routine maintenance.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If the guide means is adjustable in width and depth, then it can occupy optimal space in the channel for controlled movement, but this requires an expandable element mechanism

Engineering Contradiction:
Improveprecision of guide means positioningVSAvoidcomplexity of expandable element mechanism
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The guide means is designed with an expandable element that allows it to dynamically adjust its width and depth. The guide means can be in a first configuration (expanded) when the sash-mounted component is engaged with the frame-mounted component for precise controlled movement, and in a second configuration (collapsed) when disengaged for easy removal and replacement. This dynamic adjustment provides manufacturing precision when needed while keeping the overall system simple.

Inventive Principle:
Principle #15Dynamics

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 system maintains consistent resistance and smooth operation by adjusting the guide means' occupancy of the channel space, reducing wear and tear, and eliminating the need for leaf spring replacement.

Implementation Method 1

the expandable element is a compressible bushing

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

the expandable element and the surface of the frame-mountable component that is contactable by the expandable element having a high coefficient of friction serving to control movement between the sash-mountable and frame-mountable components

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP4215707B1A hinge for a roof window
Publication Date: 2026.03.04 KEYLITE ROOF WINDOWS
  • EP4215707B1 patent drawingFigure 1~2
  • EP4215707B1 patent drawingFigure 3
  • EP4215707B1 patent drawingFigure 4~5

AI summary

A hinge (2) for a roof window, the hinge (2) having a frame-mountable component (4) mountable to a frame (8) of a roof window, a sash-mountable component (6) mountable to a sash (12) of a roof window, wherein the frame-mountable component (4) and the sash-mountable component (6) are engageable with one another and are movable relative to one another when engaged. The frame-mountable component (4) comprises a channel (14), and wherein the sash-mountable component (6) comprises a guide arrangement (16), the guide arrangement (16) being configured to move through the channel (14) of the frame-mountable component (4) and to guide the relative movement between the frame-mountable component (4) and the sash-mountable component (6). At least part of the guide arrangement (16) is adjustable so that the guide arrangement (16) occupies more or less of the space of the channel (14) of the frame-mountable component (4).