Wrap Spring Collar for Quiet Architectural Covering Operation

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Solution Overview

Problem

Existing architectural-structure covering operating systems often suffer from misalignment of housing portions, leading to improper operation and unwanted noise due to imperfect tolerances, causing the wrap spring to snag and result in detectable clicking sounds.

Innovation Solution

Incorporation of a collar that encases the end portion of the wrap spring, allowing for proper friction and operation while enabling manufacturing with different lubricated materials, and preventing relative rotation with the housing to ensure smooth operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If housing portions are manufactured with standard tolerances, then manufacturing cost and ease of manufacture are improved, but misalignment occurs leading to improper operation and unwanted noise

Engineering Contradiction:
Improvemanufacturing with standard tolerancesVSAvoidproper operation
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

A collar component is introduced as an intermediary element between the housing portions and the wrap spring. The collar serves as a mediator that absorbs misalignment through its own degree of freedom, preventing the wrap spring from contacting misaligned housing surfaces. This intermediary component allows standard manufacturing tolerances while ensuring reliable operation by decoupling the wrap spring from direct contact with potentially misaligned housing portions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If housing portions are manufactured with tighter tolerances to prevent misalignment, then proper operation is improved, but manufacturing cost and complexity increase

Engineering Contradiction:
Improveproper operationVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The collar acts as a mediator that compensates for manufacturing tolerances. Instead of requiring precise alignment between housing portions, the collar's presence allows for standard tolerances while maintaining proper wrap spring operation. The collar absorbs the alignment variability, eliminating the need for costly tight tolerance manufacturing.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The collar introduces a new geometric parameter (its own dimensions and fit characteristics) that can be optimized to accommodate tolerance variations in the housing portions. By changing the system's geometric parameters to include this intermediate component, the design becomes more robust to manufacturing variations without increasing complexity.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the wrap spring is allowed to contact housing surfaces directly, then device complexity is reduced, but misalignment causes snagging and clicking sounds

Engineering Contradiction:
Improvesimple wrap spring contactVSAvoidclicking sounds and snagging
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The collar serves as an intermediary between the wrap spring and housing surfaces. It provides a dedicated, precisely fitted contact surface for the wrap spring, preventing the spring from contacting misaligned housing surfaces. This intermediary eliminates the harmful clicking sounds and snagging while adding minimal complexity to the overall device.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The collar acts as a thin-walled protective structure that encloses the critical interaction zone between the wrap spring and housing. This thin-walled component provides sufficient structural support to maintain alignment while allowing the wrap spring to operate smoothly without direct contact with the housing surfaces.

Inventive Principle:
Principle #30Flexible shells and thin films

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 collar addresses misalignment issues, reducing noise and ensuring proper operation by shielding the wrap spring from housing surfaces and maintaining necessary friction for efficient rotation, thus enhancing user experience and reducing product returns.

Implementation Method 1

maintaining necessary friction for efficient rotation

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3705678B1Operating system for an architectural-structure covering
Publication Date: 2024.10.02 HUNTER DOUGLAS INC
  • EP3705678B1 patent drawingFigure 1
  • EP3705678B1 patent drawingFigure 2
  • EP3705678B1 patent drawingFigure 3

AI summary

An operating system (200) for use with an architectural-structure covering for moving a covering portion of the architectural-structure covering between an extended position and a retracted position is disclosed. The operating system (200) may include a drive mechanism (210) (e.g., a drive spool (212)), a driven member (230) operatively coupled to the drive mechanism (210), a clutch mechanism (220) (e.g., a wrap spring (222)) operatively coupled to the drive mechanism (210) and the driven member (230), and a collar (300) operatively associated with the clutch mechanism (220). The collar (300) may be adapted and configured to receive an end portion of the clutch mechanism (220) so that the end portion of the clutch mechanism (220) is encased by the collar (300).