Semi-rigid Chain with Directional Bend Control for Window Treatments

Solution Overview

Problem

Existing window treatment chains, such as those used in roller shades and blinds, lack sufficient directional control and flexibility, leading to inefficient operation and potential damage when bent in certain directions.

Innovation Solution

The development of a chain for window treatments with a unique design that includes a plurality of members joined in a loop, where each member is configured to contact adjacent members to restrict bending in specific directions, thereby controlling the minimum bend radius.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a typical ball chain loop is used for window treatment operation, then the chain can be easily manufactured and operated, but the chain lacks directional control and allows bending in all directions which can cause operational inefficiency and potential damage

Engineering Contradiction:

Improvechain operationVSAvoidchain durability

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The chain is divided into individual link members, each with a specific geometry that includes a first portion and a second portion. This segmentation allows each link to independently control bending in specific directions while maintaining overall chain flexibility for operation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Each chain link member has non-uniform geometry with a first portion and a second portion having different bending characteristics. The first portion allows bending in a first direction while the second portion restricts bending in a second direction, creating local directional control throughout the chain.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If the chain allows free bending in all directions, then the chain maintains high flexibility and ease of manipulation, but the minimum bend radius becomes too small causing operational inefficiency and potential damage

Engineering Contradiction:

Improvechain flexibilityVSAvoidchain damage

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

Each chain link member has non-uniform geometry with a first portion and a second portion having different bending characteristics. The first portion allows bending in a first direction while the second portion restricts bending in a second direction, creating local directional control throughout the chain.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The chain link members feature asymmetric geometry where the first portion and second portion have different shapes and bending radii. This asymmetry creates different minimum bend radii for different bending directions, restricting bending in one direction while allowing it in another.

Inventive Principle:

Principle #4Asymmetry

3Manufacturing precision

If the chain geometry is modified to restrict bending in specific directions, then directional control and minimum bend radius are improved, but the chain structure becomes more complex

Engineering Contradiction:

Improveminimum bend radius controlVSAvoidchain structure

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The chain is divided into individual link members, each with a specific geometry that includes a first portion and a second portion. This segmentation allows each link to independently control bending in specific directions while maintaining overall chain flexibility for operation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Instead of trying to control the entire chain's bending behavior through a complex overall structure, the invention inverts the approach by embedding directional control features within each individual simple link member, making each unit self-regulating.

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS20250043630A1Semi-rigid chain for a window treatment

Publication Date: 2025.02.06 LUTRON TECHNOLOGY COMPANY LLC

AI summary

A manually-operated window treatment system includes a roller tube, a covering material, and a chain (e.g., a semi-rigid chain). The roller tube is supported at opposed ends thereof. The covering material is attached to the roller tube. The covering material is operable between a raised position and a lowered position via rotation of the roller tube. The chain is configured to be operated by a user to rotate the roller tube. The chain has a first minimum bend radius when bent in a first direction and a second minimum bend radius when bent in a second direction. The first minimum bend radius is less than the second minimum bend radius.