Lift Cord Locking Member to Prevent Hazardous Window Blind Loops

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Solution Overview

Problem

Existing window and architectural passage coverings that rely on cords pose a significant hazard to small children due to the risk of entanglement and strangulation, as they can form loops of sufficient diameter that are hazardous, and current solutions either do not eliminate this risk or are not suitable for heavier coverings.

Innovation Solution

A locking mechanism for lift cords that engages a guide ring and allows the cord to move freely in one direction to raise or lower the covering, but rotates to pinch the cord between the locking member and guide ring when pulled in a second direction, preventing the formation of hazardous loops.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional lift cords are used to raise and lower coverings, then the functionality and aesthetics of cord-based systems is maintained, but hazardous loops can form that pose entanglement and strangulation risks to children

Engineering Contradiction:
Improvefunctionality of cord-based systemVSAvoidentanglement and strangulation hazard
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

A locking member is introduced as an intermediary component between the lift cord and the covering. This locking member includes a guide ring that the lift cord passes through, and a locking mechanism that can engage with the guide ring to prevent the cord from being pulled far enough to create hazardous loops, while still allowing normal operation

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The locking member is designed with selective rotative ability, allowing it to rotate freely during normal operation to accommodate the lifting and lowering motion, but to lock in position when the cord is pulled in a direction that would create a hazardous loop, thus dynamically adapting its constraint level based on operational conditions

Inventive Principle:
Principle #15Dynamics

2Reliability

If the locking member is designed to prevent cord pull-through, then loop formation is prevented, but the cord must still move freely during normal raising and lowering operation

Engineering Contradiction:
Improveprevention of loop formationVSAvoidfree movement of cord during operation
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The locking member incorporates a dynamic locking mechanism that remains unlocked during normal vertical operation, allowing the cord to pass freely through the guide ring. When the cord is pulled in a direction that would create a hazardous loop (perpendicular or at an angle), the mechanism detects this abnormal pull direction and engages the locking feature to prevent further movement

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2666954B1Apparatuses, systems and methods for locking lift cords used to lift architectural opening coverings
Publication Date: 2016.07.20 SAFE T SHADE
  • EP2666954B1 patent drawingFigure 1A
  • EP2666954B1 patent drawingFigure 1B
  • EP2666954B1 patent drawingFigure 2

AI summary

A locking member to be used in conjunction with a guide ring and a lift cord configured to raise of lower a covering for an architectural opening, such as a window, door or the like, is disclosed. The locking member is configured to engage the guide ring and the lift cord in such a way that the locking member has a selective rotative ability, which allows the lift cord to freely move in a first direction to raise or lower the covering, but the locking member will move or rotate about the guide ring when the lift cord is pulled in a second direction to pinch the lift cord between the locking member and the guide ring so that the lift cord is prevented from being pulled away from the covering far enough to create a loop of a certain diameter.