Roof Window Lifting Device for Variable Roof Inclinations

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Solution Overview

Problem

Existing roof windows with lifting devices lack design flexibility and operability, particularly in balancing the force exerted by the lifting device to accommodate varying roof inclinations, leading to uncomfortable or hazardous operation.

Innovation Solution

A roof window with a lifting device featuring a sledge guide, lifting arm, and an adjustment system that allows for adjusting the angle between the lifting arm and adjustment arm, coupled with a spring assembly, to balance the force exerted on the secondary frame based on roof inclination, using an adjustment screw and bushing mechanism for precise adjustment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a lifting device with spring assembly is used to balance the weight of movable components, then the ease of operation is improved, but the device cannot accommodate varying roof inclinations effectively

Engineering Contradiction:
Improveease of operationVSAvoidadaptability to roof inclination
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The lifting device incorporates an adjustable arm that can be repositioned to different angles relative to the primary frame, transforming a static lifting mechanism into a dynamic one that adapts to varying roof inclinations. This allows the device to maintain optimal force balance across different installation conditions while preserving ease of operation.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the geometric parameter (angle) of the lifting arm relative to the primary frame to accommodate different roof inclinations. By adjusting this parameter, the lifting device optimizes the mechanical advantage and force distribution for each specific installation angle, thereby achieving both ease of operation and adaptability.

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If the lifting arm is directly connected to the secondary frame, then the structure is simple, but the design flexibility is limited

Engineering Contradiction:
Improvestructure simplicityVSAvoiddesign flexibility
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The lifting device is segmented into distinct functional components: a primary frame connection point, an adjustable arm with intermediate connection, and secondary frame attachment. This segmentation allows independent optimization of each component while maintaining overall structural simplicity, thereby increasing design flexibility without excessive complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The adjustable arm serves as an intermediary element between the primary frame and secondary frame, providing geometric flexibility and force distribution optimization. This intermediate component enables design flexibility by allowing angle adjustment while maintaining a relatively simple overall structure through its straightforward mechanical connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution provides increased design flexibility and ease of operability by allowing the roof window to be balanced for roof inclinations ranging from 15° to 65°, ensuring smooth operation and user safety.

Implementation Method 1

a spring assembly configured to be coupled to the sledge

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

a first end rotatably connected with a sledge slidably connected with the primary frame in a sledge guide

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

a lifting arm with a first end rotatably connected with a sledge and a second end rotatably connected with the at least one secondary frame

Methodology Applied
Scientific EffectLever: Lever

Data Source

PatentEP4390030B1Roof window with a lifting device and method of assembling a lifting device
Publication Date: 2025.10.08 VKR HOLDING AS
  • EP4390030B1 patent drawingFigure 1A
  • EP4390030B1 patent drawingFigure 1B
  • EP4390030B1 patent drawingFigure 1C

AI summary

In the roof window (100), the lifting device (10) further comprises a lifting arm (14) inserted between the primary frame (1) and the at least one secondary frame (2). The lifting arm (14) has a first end (12) rotatably connected with a sledge (30) slidably connected with the primary frame (1) in a sledge guide (16) and a second end (13) rotatably connected with the at least one secondary frame (2). The lifting device (10) further comprises a spring assembly (20) configured to be coupled to the sledge (30), an adjustment system (50) and an adjustment arm (52).