Roof Window Operator with Spring-Wound Free-Wheel Clutch

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Solution Overview

Problem

Existing roof window operating arrangements are complex and difficult to install, require significant power for operation, and lack manual override capabilities, making them expensive and hard to handle, especially when installed high in ceilings.

Innovation Solution

A roof window operating arrangement featuring a drive unit with a winding drum actuated by a spring, providing a free-wheeled mechanism for manual control and automatic winding, allowing for both automatic and manual operation with reduced resistance, using a two-part control mechanism influenced by the drive unit and spring force.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Extent of automation

If an electrically driven operating arrangement with a complex coupling mechanism is used to control the roof window, then the window can be automatically opened and closed, but the arrangement becomes expensive to produce and requires significant power for operation

Engineering Contradiction:
Improveautomatic window operationVSAvoidpower consumption
Core Design Contradiction:
Extent of automationVSUse of energy by moving object

Solution Approach 1:

The patent applies a one-way clutch mechanism that dynamically changes the coupling state between the winding drum and drive shaft based on rotation direction. During manual operation (unwinding), the clutch disengages to reduce resistance and power consumption. During automated closing, the clutch engages to transmit motor force. This dynamic state change resolves the contradiction by allowing automatic operation only when needed while enabling easy manual override.

Inventive Principle:
Principle #15Dynamics

2Reliability

If an electrically driven operating arrangement with secure coupling between male and female parts is used, then the window can be reliably controlled, but the installation becomes difficult and the components are hard to reach when installed high in the ceiling

Engineering Contradiction:
Improvereliable window controlVSAvoidinstallation ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent segments the coupling mechanism into two functional parts: a secure operational coupling (male-female connection) and a simple installation interface (spline connection). The spline connection between the operating element and winding drum allows easy assembly and disassembly during installation, while the male-female connection provides reliable control during operation. This segmentation resolves the contradiction between installation ease and operational reliability.

Inventive Principle:
Principle #1Segmentation

3Reliability

If an electrically driven operating arrangement with self-locking mechanism is used, then the window can be securely held in position, but manual override capability is lost

Engineering Contradiction:
Improvesecure position holdingVSAvoidmanual override capability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The one-way clutch creates a dynamic locking mechanism that is self-locking in one direction (preventing unintended window movement) but freely reversible in the opposite direction (allowing manual override). The clutch engages during automated closing to hold the window securely, but disengages when manual force is applied in the unwinding direction. This dynamic behavior resolves the contradiction between secure position holding and manual override capability.

Inventive Principle:
Principle #15Dynamics

4Reliability

If a complex releasable coupling mechanism with multiple components is used between sash and frame, then the window can be controlled with precise force management, but the installation becomes difficult due to the series of components that have to be fitted together

Engineering Contradiction:
Improveforce management during operationVSAvoidinstallation complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent merges the force management function and the connection function into a single integrated operating element. The operating element combines the winding drum, one-way clutch, and coupling mechanism into one component that performs both secure force management during operation and simple installation via spline connection. This merging resolves the contradiction by eliminating the need for multiple separate components while maintaining reliable force control.

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

Enables easier installation, reduced power consumption, and manual handling capabilities while maintaining automated closure, with a simple and cost-effective design that reduces operational complexity and enhances user control.

Implementation Method 1

The winding drum is actuated by a spring, which in an inactive state of the drive unit is able to rotate the winding drum in a reverse direction

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

The operator housing is provided with a drive unit comprising an electric motor connected to a drive shaft, the drive shaft being further arranged with a winding drum

Methodology Applied
Scientific EffectElectric motor force: Electromagnetic Induction

Data Source

PatentEP2957700B1Roof window operator
Publication Date: 2021.08.11 VKR HOLDING AS
  • EP2957700B1 patent drawingFigure 1
  • EP2957700B1 patent drawingFigure 2
  • EP2957700B1 patent drawingFigure 3~4

AI summary

By the invention is provided a roof window operating arrangement (10) and a roof window (1) employing the operating arrangement (10). The operating arrangement (10) is configured to provide manual opening and closing of the window (1) and further automatic closing of the window (1). The operating arrangement (10) has a winding drum (23; 123; 223) for winding up an operating element (30; 130; 230), such as a cord, in order to automatically close the window (1). The window may be manually opened because a free wheel clutch (40; 140; 240) enables the operating element (30; 130; 230) to be manually withdrawn. The operating element (30; 130; 230) is releasable from the window (1) and when released the operating element (30; 130; 230) is withdrawn into the operator housing (20; 120; 220) by a spring (24; 124; 224).