Roof Window Lifting Device with Push Arm Mechanism

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Solution Overview

Problem

Existing roof window lifting devices lack design flexibility, making it difficult to achieve the desired movement pattern and ease of operability, especially when installed on inclined roofs with varying inclinations.

Innovation Solution

The roof window features a lifting device with a lifting arm and a push arm, where the first end of the lifting arm is rotatably connected to a sledge slidably connected to the primary frame, and the first end of the push arm is rotatably connected to the sledge guide. This configuration provides increased freedom of movement for the lifting arm while maintaining stability, allowing for easier operation without requiring large forces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a traditional lifting device with direct connection between lifting arm and sledge is used, then the structure is simple, but the design flexibility and movement pattern control are insufficient

Engineering Contradiction:
Improvedesign flexibilityVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The lifting device is segmented into multiple independent components: lifting arm, push arm, sledge, and sledge guide. Each component performs a specific function and can be independently optimized. The push arm acts as an intermediary element that divides the connection between the lifting arm and sledge, allowing each segment to contribute to the overall movement pattern control without requiring the entire structure to be complex.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The push arm serves as an intermediary element between the lifting arm and the sledge. This mediator component enables indirect control of the sledge movement, providing additional degrees of freedom and allowing the lifting arm to influence the sledge position through the push arm's rotational connection to the sledge guide. This intermediary structure increases design flexibility without proportionally increasing overall complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the lifting arm is directly connected to the sledge, then the connection is simple, but the freedom of movement and stability are limited

Engineering Contradiction:
Improvefreedom of movementVSAvoidconnection complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The connection between the lifting arm and sledge is made dynamic through the push arm's rotational joint with the sledge guide. Instead of a fixed direct connection, the system allows the push arm to rotate and adjust its position, enabling the lifting arm to achieve a larger range of motion. This dynamic connection adapts during operation, providing freedom of movement while maintaining stability through the guided rotational mechanism.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If a simple lifting mechanism is used, then the device is easy to manufacture, but large forces are required to operate the window

Engineering Contradiction:
Improveforce requiredVSAvoidmanufacturing complexity
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The push arm acts as a mechanical intermediary that provides leverage and force distribution. By connecting the lifting arm to the sledge through the push arm's rotational joint with the sledge guide, the system creates a mechanical advantage that reduces the force required to move the window. The push arm's position and orientation can be optimized to distribute forces more efficiently, making operation easier without requiring complex additional mechanisms.

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 enhanced design flexibility of the lifting device allows for precise control over the movement pattern of the roof window, improving ease of operation and reducing the force required to open and close the window, even on roofs with varying inclinations.

Implementation Method 1

a spring assembly configured to be coupled to a sledge... to balance at least part of the weight of the movable components

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

the lifting arm having a first end and a second end, the second end being rotatably connected to the at least one secondary frame... the push arm having a first end and a second end, the second end being rotatably connected to the lifting arm

Methodology Applied
Scientific EffectLever: Lever

Implementation Method 3

provides a point of rotation around the push arm allowing the first end of the lifting arm to have a larger degree of freedom while still having the necessary stability to securely lift the secondary frame and without requiring large force to operate the roof window

Methodology Applied
Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP4567237A1A roof window with a lifting device
Publication Date: 2025.06.11 VKR HOLDING AS
  • EP4567237A1 patent drawingFigure 1A
  • EP4567237A1 patent drawingFigure 1B
  • EP4567237A1 patent drawingFigure 1C

AI summary

A roof window (100), comprising a stationary primary frame (1), at least one secondary frame (2), and a lifting device (10) comprising a lifting arm (14) inserted between the primary frame (1) and the at least one secondary frame (2), the lifting arm (14) having a first end (14a) rotatably connected to a sledge (30) slidably connected with the primary frame (1) in a sledge guide (16) and a second end (14b) rotatably connected to the at least one secondary frame (2), the lifting device (10) furthermore comprising a spring assembly (20) configured to be coupled to the sledge (30), the lifting device further comprising a push arm (40) having a first end rotatably connected to the sledge guide (16) and a second end rotatably connected to the lifting arm (14).