Single Cord Control System for Retractable Architectural Coverings

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Solution Overview

Problem

Conventional window covering control systems often require users to choose between multiple operating elements for raising and lowering shades or blinds, leading to confusion, especially when elements are tangled, and pose a strangulation hazard due to their length, while also lacking compatibility with all systems and needing improvements in operational smoothness and dependability.

Innovation Solution

A control system for roller tube retractable coverings using a single retractable operating element, such as a cord or cable, that allows users to move the covering between extended and retracted positions by imparting a repetitive motion, featuring an input assembly, reversible transmission, and output assembly to convert linear motion into rotational motion of a head roller, with automatic retraction and a braking feature to hold the covering in place.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a looped operating element is used to provide convenient operation, then ease of operation is improved, but the length of the operating element increases creating strangulation hazards

Engineering Contradiction:
Improveease of operationVSAvoidlength of operating element
Core Design Contradiction:
Ease of operationVSLength of moving object

Solution Approach 1:

The patent extracts the harmful looped portion of the operating element and replaces it with a retractable cord mechanism. The cord is paid out only as needed during operation and automatically retracts afterward, eliminating the persistent loop that creates strangulation hazards while maintaining the convenience of operation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the parameter of operating element length from fixed and excessive to dynamic and controlled. The retractable mechanism allows the cord length to vary based on operational needs, providing sufficient length for operation but automatically reducing it to minimal necessary length afterward, thereby eliminating strangulation hazards.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If multiple operating elements are provided to give users choices, then adaptability is improved, but device complexity increases and user confusion occurs when elements are tangled

Engineering Contradiction:
ImproveadaptabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by designing a single operating element that performs multiple functions: it raises the covering when paid out in one direction and lowers it when paid out in the opposite direction. This eliminates the need for separate operating elements for different functions, reducing complexity while maintaining adaptability.

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

Solution Approach 2:

The patent merges the functions of multiple operating elements into a single retractable cord mechanism. By combining raising and lowering operations into one unified system with directional control, it eliminates the tangling issues and complexity associated with multiple separate cords or elements.

Inventive Principle:
Principle #5Merging (Combining)

3Length of stationary object

If a longer operating element is used to raise or lower the shade, then the drop of the shade is increased, but the strangulation hazard increases

Engineering Contradiction:
Improvedrop of shadeVSAvoidstrangulation hazard
Core Design Contradiction:
Length of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The retractable cord mechanism is self-managing in terms of length control. It automatically pays out the necessary length to accommodate the shade drop and then automatically retracts to minimize exposed length, eliminating the need for manual length adjustment while preventing strangulation hazards through automatic length management.

Inventive Principle:
Principle #25Self-service

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 system simplifies operation by using a single element for both raising and lowering, reduces the risk of entanglement and strangulation, and enhances operational smoothness and dependability, ensuring compatibility with various window covering systems.

Implementation Method 1

a clock spring, which may be mounted on the spool and engaged to automatically retract the operating cord after use

Methodology Applied
Scientific EffectElastic potential energy: Elasticity

Implementation Method 2

The input assembly may include a cord spool and pulley, the pulley being connected to the spool

Methodology Applied
Scientific EffectPulley mechanism: Pulley

Data Source

PatentEP1728963B1Control system for architectural coverings with reversible drive and single operating element
Publication Date: 2013.11.06 HUNTER DOUGLAS INC
  • EP1728963B1 patent drawingFigure 1
  • EP1728963B1 patent drawingFigure 2~3
  • EP1728963B1 patent drawingFigure 4

AI summary

The present invention provides for retractable coverings for architectural openings utilizing a control system having a single operating element allowing a user to move a retractable covering between extended and retracted positions by imparting a repetitive motion to the operating element. The control system may include an input assembly, a transmission, and an output assembly cooperatively engaging to convert linear movement of the operating element into rotational movement of a head roller in the required direction to provide movement of the covering in the desired direction and distance. The input assembly may convert linear movement of the operating element into rotational movement imparted to the transmission. The input assembly may also engage the transmission to effect the direction of rotational output from the transmission. The transmission imparts rotational movement to the output assembly, which interfaces with the head roller to rotate the head roller and to provide a braking feature.