Drive Unit with Angled Protrusions for Architectural Coverings

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Solution Overview

Problem

Existing drive units for architectural opening coverings, such as window blinds, do not provide a compact and easy-to-reconnect nondestructive disconnection mechanism, which is crucial for child safety and operational efficiency, especially when dealing with continuous looped members like bead chains.

Innovation Solution

A drive unit with a drive wheel that can be securely attached to an operating wheel via angled protrusions and teeth, allowing for rotational drive while enabling axial release without damage, and a backing plate for resilient engagement with the head rail to prevent unintended detachment, facilitating safe and easy reconnection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the drive wheel is securely attached to the operating wheel to ensure reliable drive transmission, then the reliability of drive transmission is improved, but the ease of disconnection for child safety is worsened

Engineering Contradiction:
Improvereliability of drive transmissionVSAvoidease of disconnection
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The attachment mechanism transitions from a static fixed connection to a dynamic conditional connection. The drive wheel remains firmly attached during normal operation through the interference fit of tapered surfaces, but automatically becomes disconnectable when subjected to simultaneous bidirectional pulling forces that exceed a threshold, thereby resolving the contradiction between secure attachment and emergency disconnection capability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The attachment mechanism is designed with preliminary anti-action by incorporating the bidirectional force-sensing feature. Before actual disconnection occurs, the mechanism detects the hazardous condition of simultaneous pulling from both sides and prepares for automatic release, preventing child entanglement while maintaining reliable drive transmission during normal unidirectional operation

Inventive Principle:
Principle #9Preliminary anti-action

2Object-affected harmful factors

If a disconnection mechanism is provided to allow the drive wheel to separate from the operating wheel, then child safety is improved, but the device complexity increases

Engineering Contradiction:
Improvechild entanglement riskVSAvoidcomplexity of attachment mechanism
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The disconnection mechanism operates on self-service principle by automatically detecting bidirectional pulling forces and initiating separation without requiring external intervention. The drive wheel itself senses the hazardous condition through the force-transmitting attachment features and autonomously disconnects from the operating wheel, eliminating the need for additional sensors, actuators, or control systems

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The complex disconnection functionality is extracted from the main drive mechanism by implementing it through the existing attachment features between drive wheel and operating wheel. Rather than adding a separate disconnection system, the invention modifies the attachment mechanism itself to possess dual functionality: secure connection during normal operation and automatic disconnection during hazardous conditions, thereby reducing overall device complexity

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If the drive wheel and operating wheel are firmly connected to prevent accidental detachment, then reliability is improved, but the ease of reconnection after disconnection is worsened

Engineering Contradiction:
Improvestability of connectionVSAvoidease of reconnection
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The connection and disconnection actions are inverted in terms of force direction. Normal unidirectional pulling forces strengthen the connection through the tapered interference fit, while bidirectional pulling forces of sufficient magnitude initiate separation. This inversion allows the same mechanism to provide both stable connection during operation and controlled disconnection when needed, with reconnection simply requiring removal of the bidirectional force constraint

Inventive Principle:
Principle #13The other way round (Inversion)

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 solution provides a secure and compact drive mechanism that allows for safe disconnection from the operating wheel under radial or axial loads, preventing child entanglement and enabling easy reassembly without tools, thus enhancing both safety and operational convenience.

Implementation Method 1

a backing plate for resilient engagement with the head rail to prevent unintended detachment

Methodology Applied
Scientific EffectResilient engagement: Elasticity

Implementation Method 2

The attachment arrangement is configured to transfer a circumferential force in at least one of two opposite directions between the drive wheel and the operating wheel

Methodology Applied
Scientific EffectMechanical force transmission: Mechanical Force

Data Source

PatentEP3081735B1Drive unit for an architectural opening covering
Publication Date: 2023.07.12 HUNTER DOUGLAS IND BV
  • EP3081735B1 patent drawingFigure 1a
  • EP3081735B1 patent drawingFigure 1b
  • EP3081735B1 patent drawingFigure 2a~2b

AI summary

A drive unit for mounting to the head rail of an architectural opening covering, the drive unit including a drive wheel (4) and an operating wheel (12). The drive wheel (4) has an outer periphery configured to receive and support an elongate portion of a continuous looped member, and is configured to rotate about a first axis by longitudinal translation of the continuous looped member with rotation of the outer periphery about the first axis. The operating wheel (12) is configured to rotate about a second axis and to rotate a winding core of the architectural opening covering. The drive wheel (4) is releasably attached coaxially to the operating wheel (12) and is configured, when attached to the operating wheel (12), to transfer rotation of the drive wheel (4) to rotation of the operating wheel (12).