Blind Clutch Quick-Release Mechanism for Tool-Free Chain Access

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Solution Overview

Problem

Conventional chain guard housings for blinds make it difficult to remove the chain without disassembling the entire blind control unit, leading to loosened connections and potential assembly failures, and existing solutions are either hard to actuate or require tools.

Innovation Solution

A quick-release mechanism for the chain guard housing and clutch assembly that allows chain insertion or removal without disassembling the control unit, featuring a drive spline, chain wheel, and a chain cover module with a central pin and actuator, enabling axial movement prevention and easy release via a button actuator.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional chain guard housings are used to prevent chain disengagement, then chain security is improved, but chain removal becomes difficult requiring full disassembly

Engineering Contradiction:
Improvechain securityVSAvoidchain removal
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The chain guard housing is divided into a stationary outer housing and a movable inner chain cover that can be independently actuated. The quick-release actuator selectively moves only the chain cover portion, separating the function of chain retention (outer housing) from chain access (inner cover), allowing chain removal without full disassembly while maintaining security during operation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The chain cover is designed with dynamic movement capability through the quick-release actuator mechanism. The actuator translates user input into axial movement of the chain cover, dynamically changing the assembly state from locked to unlocked, enabling easy chain removal when needed while maintaining secure enclosed state during normal use.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If repeated disassembly of blind control unit is performed to remove chain, then chain access is improved, but connection reliability deteriorates due to loosened connections

Engineering Contradiction:
Improvechain accessVSAvoidconnection reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The mechanism separates chain access function from overall unit disassembly. Only the chain cover portion needs to be actuated via the quick-release mechanism, while the drive spline, chain wheel, and wall mounting bracket remain securely connected. This segmented approach provides chain access without compromising the integrity of other connections in the control unit.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The quick-release actuator is integrated directly into the chain cover assembly, allowing the chain cover to be opened and closed without external tools or intervention. The actuator mechanism itself provides the force needed to move the chain cover, making the system self-sufficient for repeated operations without affecting other connections.

Inventive Principle:
Principle #25Self-service

3Ease of operation

If roller blind assembly is removed from tube to release chain cover, then chain removal is enabled, but assembly integrity is compromised and reassembly becomes difficult

Engineering Contradiction:
Improvechain removalVSAvoidreassembly complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The design isolates the chain cover as a separate, independently actuated component from the main roller blind assembly. The quick-release actuator is positioned at the second end of the assembly, allowing the chain cover to be opened without removing the drive spline from the roller blind tube or disconnecting wall mounting brackets, greatly simplifying both removal and reassembly procedures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The quick-release actuator serves as an intermediary mechanism that mediates between user input and chain cover movement. It translates simple button pressing into the complex coordinated movements needed to release the deformable legs and move the chain cover, making the operation simple for users while maintaining secure connections throughout the assembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Stability of the object's composition

If tight fit between blind control unit and roller blind tube is maintained, then connection stability is improved, but repeated disassembly becomes increasingly difficult

Engineering Contradiction:
Improveconnection stabilityVSAvoiddisassembly ease
Core Design Contradiction:
Stability of the object's compositionVSEase of operation

Solution Approach 1:

The mechanism creates a segmented disassembly path where only the chain cover portion needs to be accessed for chain removal. The tight fit between the drive spline and roller blind tube is preserved for connection stability, while the chain cover's independent quick-release mechanism provides easy access without requiring loosening or removal of the tight-fit connections.

Inventive Principle:
Principle #1Segmentation

5Ease of operation

If quick-release mechanism is made accessible in tight spaces, then ease of operation is improved, but mechanism complexity increases

Engineering Contradiction:
Improveactuator accessibilityVSAvoidmechanism complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The quick-release actuator is positioned at the second end of the assembly, extending the control interface to a location that is more accessible in the vertical dimension. This positioning allows users to reach the actuator button from above or below rather than having to access tight lateral spaces between the wall and blind control unit, improving accessibility without requiring overly complex linkage mechanisms.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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

Enables quick and tool-free chain installation or replacement without dismounting the blind, maintaining secure connections and preventing assembly failures, while allowing for easy reassembly.

Implementation Method 1

a central pin (114, 214) extending from the drive spline at the first end, the central pin comprising at least one deformable leg (115, 215) engaged with the chain cover (131, 231) via an outward facing catch face (116, 216) on the leg

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a quick release actuator (140, 240) located at a second end of the assembly comprising an inner annular abutment surface (145, 245) in contact with the at least one leg (115, 215)

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP3521545B1Clutch for blinds
Publication Date: 2020.05.13 DECORA BLIND SYST
  • EP3521545B1 patent drawingFigure 1~2
  • EP3521545B1 patent drawingFigure 3
  • EP3521545B1 patent drawingFigure 4~5

AI summary

The present invention relates to a chain guard housing and clutch assembly (100, 200) for a blind comprising: a first end (100', 200') which is able to be inserted into a roller blind tube; a second end (100", 200") engageable with a wall mounting bracket; a drive spline (110, 210) forming the outer part of the chain guard housing and clutch assembly (100, 200) which is able to engage with the inside of a roller blind tube; a chain wheel (120, 220) , connected to the drive spline (110, 210) ; a chain cover module (130, 230) comprising a rim (132, 232) , the rim covering part of the chain wheel (120, 220) ; a central pin (114, 214) extending from the drive spline (110, 210) at the first end (100', 200') , the central pin (114, 214) comprising at least one deformable leg (115, 215) engaged with the chain cover (130, 230) via an outward facing catch face (116, 216) on the leg (115, 215) , thus preventing axial movement of the chain cover module (130, 230) relative to the drive spline (110, 210) ; and a quick release actuator (140, 240) located at a second end (100", 200") of the assembly comprising an inner annular abutment surface (144, 244) in contact with the at least one leg (115, 215).