Uni-directional Lift Control Unit for Architectural Coverings

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Solution Overview

Problem

Existing control systems for architectural openings, such as windows and doors, pose a risk of physical harm to infants and young children due to endless pull cords, and there is a need for safer alternatives that allow for incremental operation and gravity-assisted retraction of coverings.

Innovation Solution

A control unit with a uni-directional drive assembly and a one-way brake system, where a pull cord is used to incrementally raise or lower coverings and a release system allows for gravity-assisted extension, eliminating the risk of loop formation and enabling safe operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If endless pull cords are used to operate coverings, then the covering can be easily controlled, but physical harm may occur to infants and young children due to loop formation

Engineering Contradiction:
Improvecontrollability of coveringVSAvoidphysical harm risk to children
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent removes the harmful endless loop configuration and extracts only the necessary functional elements. The pull cord is made finite with secure ends, eliminating the loop that causes harm while preserving the pull-cord operation mechanism for controlling the covering.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the potential harm of cord loops into a benefit by using the pull cord's linear configuration with secure ends. This design eliminates the strangulation risk while maintaining ease of operation, and the cord's tension mechanism still enables effective control of the covering position.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If a uni-directional drive system is used to eliminate looped cords, then safety is improved, but the system complexity increases due to additional components

Engineering Contradiction:
Improvesafety from looped cordsVSAvoidcontrol system components
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent combines the drive mechanism, brake assembly, and pull cord system into an integrated control unit. This merging of components achieves the safety function of eliminating loops while managing system complexity through consolidation rather than separate discrete parts.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control unit is designed as a multi-functional device that integrates the pull cord operation, uni-directional drive, and brake control into a single assembly. This universal design accomplishes multiple functions (safety, drive, positioning) within one compact unit, balancing safety requirements with manageable complexity.

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

3Measurement precision

If a brake assembly is added to retain the covering at any position, then positioning precision is improved, but the device complexity increases

Engineering Contradiction:
Improvepositioning precision of coveringVSAvoidcontrol unit components
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The brake assembly is integrated into the control unit along with the drive mechanism and pull cord system. This consolidation provides precise positioning capability while managing complexity by combining multiple functions into a single modular assembly rather than separate distributed components.

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 solution provides a safe and efficient method for operating architectural coverings, allowing incremental retraction and gravity-assisted extension, reducing the risk of injury from looped cords and enabling precise control over the covering's position.

Implementation Method 1

a return spring biasing the spool in a wrapping direction

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

a brake assembly operatively associated with the drive assembly wherein the brake assembly selectively prevents the shade from dropping by gravity

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 3

the covering is allowed to be extended by gravity upon the release of a brake

Methodology Applied
Scientific EffectGravitation: Gravitation

Data Source

PatentEP2208852A2Control unit for lift system for coverings for architectural openings
Publication Date: 2010.07.21 HUNTER DOUGLAS INC
  • EP2208852A2 patent drawingFigure 1~2
  • EP2208852A2 patent drawingFigure 3~4
  • EP2208852A2 patent drawingFigure 5

AI summary

A control unit for controlling a lift system in a covering for an architectural opening includes a drive assembly and a brake assembly. The drive assembly includes a spool about which a pull cord can be wrapped or unwrapped and a spring for biasing the spool in a direction to wrap the pull cord thereabout. A drive gear is operatively associated with the spool so that upon a pulling of the pull cord and unwrapping of the cord from the spool, the drive gear is shifted axially into engagement with a driven gear in the brake assembly. The driven gear under such circumstances rotates a driven shaft, which in turn rotates a lift shaft in the covering to raise the covering from an extended position to a retracted position.